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Wyszukujesz frazę "sliding" wg kryterium: Temat


Tytuł:
Sliding mode control of periodic review perishable inventories with multiple suppliers and transportation losses
Autorzy:
Bartoszewicz, A.
Maciejewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/200764.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
discrete time sliding mode control
sliding surface design
inventory control
Opis:
The purpose of this paper is to develop robust and computationally efficient supply chain management strategy ensuring fast reaction to the demand variations for periodic review perishable inventory systems. For that purpose, we apply a sliding mode approach and we propose a new discrete time warehouse management strategy. The strategy employs the sliding hyperplane appropriately designed to ensure a dead-beat performance of the closed loop system. Our strategy not only explicitly takes into account decay of goods stored in the warehouse (perishing inventories) but it also accounts for transportation losses which take place on the way from suppliers to the warehouse. The proposed strategy ensures full customers’ demand satisfaction, minimizes the on-hand inventory volume and prevents from exceeding the warehouse capacity. This reflects the need of simultaneous minimization of the lost sales costs and inventory holding costs. Furthermore, the strategy ensures that the ordered quantities of goods are always non-negative and upper bounded. These favourable properties of the proposed strategy are formally stated as a lemma and three theorems and proved in the paper.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2013, 61, 4; 885-892
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surgical trap of a routine procedure. Scrotal hernia with concomitant sliding of the urinary bladder – case report
Autorzy:
Cybułka, Bartosz
Podgórny, Marek
Rapeła, Jacek
Wach, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/1394320.pdf
Data publikacji:
2015
Wydawca:
Index Copernicus International
Tematy:
scrotal hernia
sliding hernia
sliding of the urinary bladder
scrotal cystocele
Opis:
The content of the hernial sac may comprise peritoneal cavity elements, such as small and large bowel loops, visceral adipose tissue, the greater omentum, appendix (amyand hernia), and Meckel's diverticulum. The sliding of part of the urinary bladder wall to the inguinal canal is rare, being observed in 1%-4% (0.5%-3%) of inguinal hernia cases. Complete migration of the urinary bladder to the scrotum is considered a rare anomaly. As of today, 100 such cases have been described.
Źródło:
Polish Journal of Surgery; 2015, 87, 11; 587-591
0032-373X
2299-2847
Pojawia się w:
Polish Journal of Surgery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ siły docisku zestyku na parametry zestyków ślizgowych stosowanych w elektrycznej trakcji kopalni miedzi
Influence of contact force on the performance of dc sliding contacts in copper mine electric rail transport
Autorzy:
Miedziński, B.
Okraszewski, Z.
Habrych, M.
Wandzio, J.
Powiązania:
https://bibliotekanauki.pl/articles/187016.pdf
Data publikacji:
2009
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technik Innowacyjnych EMAG
Tematy:
parametry zestyków slizgowych
zestyk ślizgowy
performance of sliding contacts
sliding contact
Opis:
W artykule przedstawiono wyniki badań wpływu wartości siły docisku zestyku w stykach ślizgowych prądu stałego stosowanych w układach zasilania elektrycznej trakcji kopalnianej w kopalni miedzi na ich podstawowe parametry eksploatacyjne. Badania miały na celu znalezienie rozwiązania umożliwiającego zastąpienie dotychczas stosowanych ślizgów grafitowych, charakteryzujących się dużym zużyciem i uszkodzeniami mechanicznymi materiału, dużymi lokalnymi stratami energii i związanymi z nimi lokalnymi przegrzewaniami. Zaproponowano zastosowanie nowych ślizgów wykonanych z materiału kompozytowego miedź-molibden. Na podstawie przeprowadzonych badań sformułowano wnioski praktyczne odnośnie do efektywności wymiany ślizgów grafitowych na ślizgi wykonane z materiału kompozytowego typu Cu-Mo.
The paper features the test results of the influence of contact force on the basic performance parameters of DC sliding contacts used in the electric drives in copper mine electric rail transport. The tests aimed at finding a solution to replace the sliding contacts made of graphite which demonstrated excessive wear, mechanical damages of the material, significant local energy losses, and related local overheating. The new sliding contacts were proposed, made of a copper-molybdenum composite material. Based on the performed tests results, practical conclusions were drawn with respect to the efficiency of replacing the graphite sliding contacts with the contacts made of the copper-molybdenum composite material.
Źródło:
Mechanizacja i Automatyzacja Górnictwa; 2009, R. 47, nr 4, 4; 15-26
0208-7448
Pojawia się w:
Mechanizacja i Automatyzacja Górnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model of a sliding gate controlled by a PLC driver
Autorzy:
Majcher, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/376511.pdf
Data publikacji:
2019
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
PLC
sliding gate
visualisation
Opis:
Due to low costs, PLC controllers are used not only in technological processes but also in everyday life. The article presents the possibility of using a PLC controller to control the operation of a sliding gate. For this purpose, a design was created and a sliding gate model made controlled with a Siemens S7-1200 PLC controller. This model is used to develop various gate control algorithms, especially for appropriate gate protection against crushing or uncontrolled closing. In addition, this model is connected via the Internet to a stand equipped with the SCADA application. The iFix 5.8 PL application was used to visualise the operation of the door, which, by means of a communication driver, allows the elevator operation to be controlled remotely. In addition, elements are shown in a graphic way, whereby it is possible to assess the position of the gate.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2019, 99; 191-199
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of sliding surface on the performances of adaptive sliding mode slip ratio controller for a HEV
Autorzy:
Dash, B. K.
Subudhi, B.
Powiązania:
https://bibliotekanauki.pl/articles/229381.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sliding mode control
slip ratio control
hybrid electric vehicle
sliding surface
ABS
Opis:
Slip ratio control of a ground vehicle is an important concern for the development of antilock braking system (ABS) to avoid skidding when there is a transition of road surfaces. In the past, the slip ratio models of such vehicles were derived to implement ABS. It is found that the dynamics of the hybrid electric vehicle (HEV) is nonlinear, time varying and uncertain as the tire-road dynamics is a nonlinear function of road adhesion coefficient and wheel slip. Sliding mode control (SMC) is a robust control paradigm which has been extensively used successfully in the development of ABS of a HEV. But the SMC performance is influenced by the choice of sliding surface. This is due to the discontinuous switching of control force arising in the vicinity of the sliding surface that produces chattering. This paper presents a detailed study on the effects of different sliding surfaces on the performances of sliding mode based adaptive slip ratio control applied to a HEV.
Źródło:
Archives of Control Sciences; 2013, 23, 2; 187-203
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adaptive fuzzy-sliding mode controller for trajectory tracking control of quad-rotor
Autorzy:
Simoud, Lahcen
Kadri, Boufeldja
Bousserhane, Ismail Khalil
Powiązania:
https://bibliotekanauki.pl/articles/384825.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
quadrotor UAV
sliding mode control
adaptive PD-Slidng mode controller
fuzzy PD-sliding mode
Opis:
This paper deals with the design of an adaptive-fuzzy-PD-Sliding mode controller to achieve stabilization of a quadrotor aircraft in the presence of wind disturbance. Firstly, the dynamic system modeling is carried out using Euler-Lagrange formalism. Then, an adaptive PD-sliding mode control system with an integral-operation switching surface is investigated for quadrotor desired trajectory tracking. Finally, an adaptive fuzzy-PD-sliding mode controller is proposed to achieve control objectives and system stabilization where the fuzzy logic system used to dynamically control parameters settings of the PD-sliding mode equivalent control law. Effectiveness and robustness of the proposed control scheme is verified through simulation results taking into account external disturbances. The simulation results of a quadrotor aircraft control with the proposed controller demonstrate the high performance during flight such as null tracking error and robustness in the presence of external disturbances.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2020, 14, 2; 15-24
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Filtered integral sliding mode control in a two-mass drive system
Autorzy:
Dróżdż, P.
Szabat, K.
Powiązania:
https://bibliotekanauki.pl/articles/1193310.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
filtered integral sliding mode control
integral sliding mode control
two-mass system
chattering alleviation
Opis:
The paper presents issues related to the application of filtered integral sliding mode control to a two-mass drive system. A classical control structure has been presented and its design procedure is shown in detail. The properties of the classical structure, in which the chattering phenomenon seems to be a big drawback, have been summarized. In order to eliminate this phenomenon, an output low-pass filter has been proposed and the performance of this system has been tested. In order to improve its characteristics, an adaptive low-pass filter has been proposed. The bandwidth of the filter was changed on-line by the fuzzy system according to the current state of the plant. During the steady-states, the bandwidth is low to eliminate chattering effect, and during transients higher in order to ensure the fast dynamics of the plant.
Źródło:
Power Electronics and Drives; 2017, 2, 37/1; 121-134
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gravity- and Turbulence-Dominated Sediment Motion in the Clear-Water Scour Process at a Vertical-Wall Abutment in Pressurized Flow
Autorzy:
Radice, A.
Ballio, F.
Tran, C. K.
Powiązania:
https://bibliotekanauki.pl/articles/241458.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
abutment scour
sediment kinematics
turbulence
sliding
Opis:
Results on the motion of sediment particles on the bottom of the erosion hole are shown for a clear-water scour experiment with a vertical-wall abutment. The paper presents an investigation of particle kinematics starting from the division of the grain instantaneous movements into two populations, namely the "turbulence-dominated" events (those in which the particle motion is triggered by the turbulent flow field) and the "gravity-dominated" events (those in which the particles slide along the slopes of the scour hole due to geotechnical instability). Attention is focused on the well developed stages of the erosion process. For such experimental times, the action of the principal vortex system is particularly evident because the latter is not much stretched along the direction of the mean flow deviation, thanks to the increased flowing area. At the same time, the temporal unsteadiness of the vortices lets a bimodal behaviour of the sediments to emerge. A relevant difference has been found between the dynamics of gravity-dominated and turbulence-dominated events. In addition, it was found that the presence of geotechnical effects in the erosion hole may significantly alter the scour rate. Potential implications of the present results for the modelling of local scour processes are described.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2010, 57, 1; 43-59
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tribological properties of surface layer with boron
Autorzy:
Lubas, J.
Powiązania:
https://bibliotekanauki.pl/articles/242091.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
wear
sliding friction
surface treatment
boron
Opis:
The aim of the present work is to determine the influence of technologically produced boron surface layers on the friction parameters in the sliding pairs under the conditions of mixed friction. The tribological evaluation included ion nitrided, pack borided, laser borided, quenched and tempered surface layers and TiB2 coating deposited on 38CrAlMo5-10, 46Cr2 and 30MnB4 steels. Modified surface layers of annular samples were matched under test conditions with counter-sample made from AlSn20 bearing alloy. Tested sliding pairs were lubricated 15 W/40 Lotos mineral engine oil. The tribological tests were conducted on a T-05 block on ring tester. The applied steel surface layer modification with boron allow creating surface layers with pre-determined tribological characteristics reąuired for the elements of kinematic pairs operating in the conditions of sliding friction. Pack boronizing reduces the friction coefficient during the start-up of the frictional pair and the maximum start-up resistance level is similar to the levels of pairs with nitrided surface layers. Paper present comparison between surface roughness of annular sample and countersample before and after test, influence of surface treatment annular sample on change of friction coefficient vs. rotation speed and load, influence of surface treatment annular sample on moment of friction in function load of kinematics pair, influence of surface treatment annular sample on friction forces and temperature depending on load, as well as influence of surface treatment annular sample on wear of AlSn20 bearing alloy under various load conditions.
Źródło:
Journal of KONES; 2009, 16, 3; 213-221
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Strategie sterowania ślizgowego z ruchomą hiperpowierzchnią przełączeń - krótki przegląd
Sliding Mode Control Strategies with a Time-Varying Switching Hypersurface - a Brief Survey
Autorzy:
Latosiński, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/275701.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
teoria sterowania
sterowanie ślizgowe
ruchome hiperpowierzchnie przełączeń
control theory
sliding mode control
time-varying sliding hypersurface
Opis:
Strategie sterowania ślizgowego są cenione za swoją całkowitą niewrażliwość na klasę zakłóceń i niepewności modelu. Uzyskanie tej właściwości jest możliwe przez sprowadzenie punktu opisującego dynamikę układu na pewną hiperpowierzchnię przełączeń zdefiniowaną w przestrzeni stanów. W początkowym etapie sterowania, w którym punkt opisujący zbliża się do tej hiperpowierzchni, układ pozostaje wrażliwy na zakłócenia, co utrudnia projektowanie skutecznych strategii sterowania ślizgowego. Aby zapewnić odporność układu na zakłócenia i niepewności modelu na wszystkich etapach procesu sterowania liczni autorzy zaproponowali zastosowanie ruchomych hiperpowierzchni przełączeń. Celem niniejszego artykułu przeglądowego jest przedstawienie najważniejszych osiągnięć z zakresu sterowania ślizgowego z wykorzystaniem takich hiperpowierzchni. Omówione są pionierskie prace proponujące zastosowanie ruchomych hiperpowierzchni przełączeń oraz przedstawione są metody ich projektowania. Następnie podkreślone są najważniejsze osiągnięcia z zakresu sterowania ślizgowego wykorzystującego ruchome hiperpowierzchnie przełączań zarówno dla układów ciągłych jak i dyskretnych.
Sliding mode control strategies are valued for their total insensitivity to the class of disturbances and uncertainty of the model. Obtaining this property is possible by bringing a point describing the dynamics of the system to a certain switching hypersurface defined in the state space. At the initial stage of control, where the description point approaches this hypersurface, the system remains sensitive to interferences, which hinders the design of effective sliding mode control strategies. To ensure the system’s resistance to interference and model uncertainty at all stages of the control process, many authors proposed the use of mobile switching hypersurfaces. The purpose of this review article is to present the most important achievements in the area of sliding mode control using such hypersurfaces. Discussed are pioneering works proposing the use of mobile switching hypersurfaces and methods of their design are presented. Next, the most important achievements in the area of sliding mode control using movable switching hypersurfaces for both continuous and discrete systems are highlighted.
Źródło:
Pomiary Automatyka Robotyka; 2020, 24, 1; 41-47
1427-9126
Pojawia się w:
Pomiary Automatyka Robotyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laboratoryjna ocena wpływu nacisku i prędkości ślizgania na intensywność zużycia stali obręczowej gatunku B6T przy suchym tarciu ślizgowym
Laboratory assessment of the influence of contact pressure and sliding speed on wear rate of a tyre steel grade B6T in dry sliding conditions
Autorzy:
Witaszek, M.
Witaszek, K.
Powiązania:
https://bibliotekanauki.pl/articles/198289.pdf
Data publikacji:
2008
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
prędkość ślizgania
stal obręczowa
B6T
suche tarcie ślizgowe
sliding speed
tyre steel
dry sliding conditions
Opis:
Koła kolejowe są odpowiedzialnymi elementami o dużym wpływie na bezpieczeństwo i niezawodność przewozów. Ich zużywanie, będące skutkiem tarcia pomiędzy kołami a szynami, jest ważną przyczyną utraty właściwości użytkowych. Zużywanie to zależy między innymi od takich czynników, jak nacisk i prędkość ślizgania. W pracy przedstawiono wyniki badań wpływu tych czynników na zużycie stali gatunku B6T stosowanej na obręcze kół lokomotyw.
Rail wheels are responsible elements with significant influence on the transport safety and reliability. Their wear, caused by a wheel - rail friction, is an important cause of wheels deterioration. This wear is strongly influenced by such factors as contact pressure and sliding velocity In the present work the influence of tat factors on dry, sliding wear of a tyre steel grade B6T is studied. This steel is used for locomotive tyres manufacturing.
Źródło:
Zeszyty Naukowe. Transport / Politechnika Śląska; 2008, 64; 267-274
0209-3324
2450-1549
Pojawia się w:
Zeszyty Naukowe. Transport / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust impedance control of a piezoelectric stage under thermal and external load disturbances
Autorzy:
Zareinejad, M.
Rezaei, S. M.
Ghidary, S. S.
Abdullah, A.
Motamedi, M.
Powiązania:
https://bibliotekanauki.pl/articles/969687.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
piezoelectric actuator
sliding mode
impedance control
hysteresis
Opis:
Piezoelectric actuators are widely used in micromanipulation tasks such as atomic force microscopy and cell manipulation. However, the hysteresis nonlinearity and the creep reduce their fidelity and cause difficulties in the micromanipulation control procedure. Besides, variation of temperature and external loads could change the model parameters identified for the piezo actuator. In this paper, a novel feedforward-feedback controller is proposed. The modified Prandtl-Ishlinskii model is utilized to linearize the actuator hysteresis in feedforward scheme and a sliding mode based impedance control with perturbation estimation is used to cancel out the thermal and external load disturbances in feedback scheme. The efficiency of the proposed controller is verified by experiments.
Źródło:
Control and Cybernetics; 2009, 38, 3; 635-648
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The application of CrN and TiN coatings in slide bearing kinematic coupling pin surface layer modification processes
Autorzy:
Lubas, J.
Powiązania:
https://bibliotekanauki.pl/articles/244165.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
TiN
CrN
wear
sliding friction
surface treatment
Opis:
This work presents the results of tribological stand tests of slide bearings with pins modified with CrN and TiN coatings and pins with a TiN-steel 46Cr2 and CrN-steel 46Cr2 ,,ring" structure. The ,,rin" structure samples features materials with different tribological properties in the form of rings on the pin slide surface. Such a structure is obtained when covering the 46Cr2 steel pin base with a discrete layer of TiN or CrN, using the PVD method. The stand tests of frictional couplings have been performed for the frictional kinematic coupling pin with modified surface layer and CuPb30 and AlSn20 alloy bearing liner slice. During the tests the tribological couplings were lubricated with Castrol magnatec engine oil (5W/40). The tests were performed on a T-05 tribological tester. The test results demonstrated the tribological advantageous using the "ring" structure samples in the frictional couplings. The tests demonstrated that the friction forces and the bearing material quantity wear were the least for couplings with CrN steel, 46Cr2 and nitrogen hardening, and the largest for TiN pin couplings. Modification of the CrN pin surface layer has a beneficial impact on reducing frictional resistance, and temperature reduction in the friction area as well as reduction in bearing alloy wear.
Źródło:
Journal of KONES; 2008, 15, 2; 263-267
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Control of an Induction Motor Using Sliding Mode Linearization
Autorzy:
Etien, E.
Cauet, E.
Rambault, L.
Champenois, G.
Powiązania:
https://bibliotekanauki.pl/articles/908504.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
automatyka
induction motor
sliding mode control
linearization
Opis:
Nonlinear control of the squirrel induction motor is designed using sliding mode theory. The developed approach leads to the design of a sliding mode controller in order to linearize the behaviour of an induction motor. The second problem described in the paper is decoupling between two physical outputs: the rotor speed and the rotor flux modulus. The sliding mode tools allow us to separate the control from these two outputs. To take account of parametric variations, a model-based approach is used to improve the robustness of the control law despite these perturbations. Experimental results obtained with a laboratory setup illustrate the good performance of this technique.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2002, 12, 4; 523-531
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Does water lubrication affect friction differently for rocks and soils? Evidence and open questions
Autorzy:
Cafaro, F.
Hamad, A.
Monterisi, L.
Powiązania:
https://bibliotekanauki.pl/articles/2172879.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
water lubrication
friction scale
fracture
sliding
roughness
Opis:
The present paper focuses on the shear strength exhibited by rocks and soils when sliding along dry and wet surfaces, with this mechanism of failure being strongly related to the water lubrication phenomenon. It is well known that the frictional behaviour of geomaterials requires multiscale investigation. Under this perspective, experimental evidence of both friction at the grain scale (i.e. interparticle friction) and friction along sliding surfaces of rock and granular soil samples (i.e. surface friction) are analysed by using data from the literature. The review is addressed at linking different scales, stating the differences between rocks and soils in terms of frictional response to sliding and trying to point out still open problems for the research.
Źródło:
Studia Geotechnica et Mechanica; 2022, 44, 3; 211--223
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sliding mode control for longitudinal aircraft dynamics
Autorzy:
Iskrenovic-Momcilovic, O.
Powiązania:
https://bibliotekanauki.pl/articles/385149.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
aircraft dynamics
control
elevator
longitudinal
sliding mode
Opis:
The control of the longitudinal aircraft dynamics is challenging because the mathematical model of aircraft is highly nonlinear. This paper considers a sliding mode control design based on linearization of the aircraft, with the pitch angle and elevator deflection as the trim variables. The design further exploits the decomposition of the aircraft dynamics into its short-period and phugoid approximations. The discrete-time variable structure system synthesis is performed on the base of the elevator transfer function short-period approximation. This control system contains a sliding mode controller, an observer, based on nominal aircraft model without finite zero and two additional control channels for the aircraft and for the aircraft model. The realised system is stable and robust for parameter and external disturbances.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2018, 12, 3; 55-60
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Continuous and discrete sliding mode control of an active car suspension system
Autorzy:
Łuczko, J.
Ferdek, U.
Powiązania:
https://bibliotekanauki.pl/articles/280694.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
sliding mode control
active damping
car suspension
Opis:
In this paper, sliding mode control (SMC) algorithms are tested for their use in an active car suspension system. Using the quarter model of the car as an example, the comparison of the efficiency of the algorithms is made. A continuous and two discrete versions of the sliding mode control are taken into consideration. The study is limited to finding the relation between the control parameters and the comfort factor. This is done by analyzing the response of the model to the harmonic and impulse excitation.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 1; 3-11
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An itae optimal sliding mode controller for systems with control signal and velocity limitations
Autorzy:
Pietrala, Mateusz
Leśniewski, Piotr
Bartoszewicz, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/2204689.pdf
Data publikacji:
2023
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
sliding mode control
optimal control
state constraints
Opis:
In this paper, a sliding mode controller, which can be applied for second-order systems, is designed. Robustness to external disturbances, finite regulation time and a good system’s behaviour are required for a sliding mode controller. In order to achieve the first two of these three goals, a non-linear, time-varying switching curve is introduced. The representative point (state vector) belongs to this line from the very beginning of the control process, which results in elimination of the reaching phase. The stable sliding motion along the switching curve is provided. Natural limitations such as control signal and system’s velocity constraints will be taken into account. In order to satisfy them, the sliding line parameters will be properly selected. However, a good dynamical behaviour of the system has to be provided. In order to achieve that, the integral time absolute error (ITAE) quality index will be introduced and minimised. The simulation example will verify theoretical considerations.
Źródło:
Acta Mechanica et Automatica; 2023, 17, 2; 230--238
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dead-Beat and reaching law based sliding mode control laws for perishable inventories with transportation losses
Autorzy:
Bartoszewicz, A.
Maciejewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/229507.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sliding mode control
perishable inventories
inventory control
Opis:
This paper describes discrete sliding mode (SM) supply management strategies for inventory systems with perishable goods and transportation losses. In the considered systems, the stock used to satisfy the unknown, bounded and time-varying demand is replenished with some delay from a distant supply source. The on-hand stock deterioration during lead-time delay, as well as commodity losses in supply process are explicitly taken into account. Two supply management strategies are proposed. The first one ensures fast reaction to the imposed demand variations, but may result in excessive control signal magnitude at the beginning of the inventory management process. Therefore, in order to conform to supplier limitations we also develop an alternative control strategy based on the concept of the reaching law. That strategy helps reduce the initial supply rate and satisfy the supplier limitations. A number of desirable properties of both proposed strategies are formulated and formally proved. These properties include full customer demand satisfaction and elimination of the risk of exceeding the warehouse capacity.
Źródło:
Archives of Control Sciences; 2012, 22, 3; 255-272
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new strongly predefined time sliding mode controller for a class of cascade high-order nonlinear systems
Autorzy:
Abadi, Ali Soltani Sharif
Hosseinabadi, Pooyan Alinaghi
Mekhilef, Saad
Ordys, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/229682.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
predefined time
stability
sliding mode
trajectory
synchronization
Opis:
Many real-time systems can be described as cascade space-state models of different orders. In this paper, a new predefined controller is designed using a Strongly Predefined Time Sliding Mode Control (SPSMC) scheme for a cascade high-order nonlinear system. The proposed control scheme based-on SMC methodology is designed such that the system states reach zero within a determined time prior to performing numerical simulation. Moreover, Fixed Time Sliding Mode Control (FSMC) and Terminal Sliding Mode Control (TSMC) schemes are presented and simulated to provide a comparison with the proposed predefined time scheme. The numerical simulation is performed in Simulink/MATLAB for the proposed SPSMC and the other two existing methods on two examples: second and of third order to demonstrate the effectiveness of the proposed SPSMC method. The trajectory tracking of the ship course system is addressed a san example of a second-order system. Synchronization of two chaotic systems, Genesio Tesi and Coullet, is considered as an example of a third-order system. Also, by using two performance criteria, a thorough comparison is made between the proposed predefined time scheme, SPSMC, and the two no predefined time schemes, FSMC and TSMC.
Źródło:
Archives of Control Sciences; 2020, 30, 3; 599-620
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of PI sliding mode control for Zeta DC-DC converter in PV system
Autorzy:
Hasanah, Rini Nur
Ardhenta, Lunde
Nurwati, Tri
Setyawati, Onny
Sawitri, Dian Retno
Suyono, Hadi
Taufik, Taufik
Powiązania:
https://bibliotekanauki.pl/articles/2173675.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
photovoltaic
Zeta converter
sliding mode control
PI sliding surface
fotowoltaika
konwerter Zeta
sterowanie trybem przesuwnym
powierzchnia ślizgowa PI
Opis:
Solar energy has become one of the most potential alternative energies in the world. To convert solar energy into electricity, a photovoltaic (PV) system can be utilized. However, the fluctuation of sunlight intensity throughout the day greatly affects the generated energy in the PV system. A battery may be beneficial to store the generated energy for later use. A DC–DC converter is commonly exploited to produce a constant output voltage during the battery charging process. A Zeta converter is a DC–DC converter which can be used to produce output values above or below the input voltage without changing the polarity. To deal with the inherent non-linearity and time-varying properties of the converter, in this paper the sliding mode control (SMC) is first analyzed and exploited before being integrated with a proportional-integral (PI) control to regulate the output voltage of the PV system. Disturbances are given in the form of changes in input voltage, reference voltage, and load. Voltage deviation and recovery time to reach a steady-state condition of the output voltage after disturbances are investigated and compared to the results using a proportional-integral-differential (PID) controller. The results show that the proposed control design performs faster than the compared PID control method.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 3; art. no. e140952
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Neural Network based control of Robot Manipulator
Autorzy:
Ohri, Arnav
Salim, Salim
Powiązania:
https://bibliotekanauki.pl/articles/1075537.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
RBF Neural Network
Robotic Manipulator
Sliding Mode Control
Opis:
This article proposes an RBFNN (Radial Basis Function Neural Network) and sliding mode based controller to manipulate the robot manipulator. The technique used has been based on a sliding mode control approach that can drive the system towards a sliding surface by Gaussian radial basis function neural network based tuned-controller.
Źródło:
World Scientific News; 2019, 121; 9-16
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and implementation of improved sliding mode controller on 6R manipulator
Autorzy:
Korayem, M. H.
Nekoo, S. R.
Khademi, A.
Abdollahi, F.
Powiązania:
https://bibliotekanauki.pl/articles/280702.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
improved sliding mode control
chattering
DLCC
hardware implementation
Opis:
In this work, we present an improved sliding mode control (ISMC) technique designed and implemented for control of 6R manipulator. Sliding mode control (SMC) is a well-known nonlinear robust method for controlling systems in the presence of uncertainties and disturbances and systems with complex dynamics as in manipulators. Despite this good property, it is difficult to implement this method for the manipulator with a complex structure and more than three degree-of-freedom because of the complicated and massive equation and chattering phenomenon as a property of SMC in control inputs. Here, the chattering phenomenon is eliminated by using an effective algorithm called ISMC and implemented to 6R manipulator by using a low-cost control board based on an ARM microcontroller with high accuracy and memory. The carrying load is considered as the uncertainty for the manipulator, while the dynamic load carrying capacity (DLCC) is considered as a robot performance criterion showing robustness of the controller. The results of simulations and experiments show that the proposed approach has a good performance and is suitable and practical to be applied for manipulators.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 1; 265-280
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gęstość pracy tarcia oraz intensywność zużycia materiału panewek łożysk ślizgowych
The work density of the friction and the wear journal bearing sleve material
Autorzy:
Murdzia, E.
Wójcicki, R.
Powiązania:
https://bibliotekanauki.pl/articles/387660.pdf
Data publikacji:
2009
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
tarcie
łożysko ślizgowe
zużycie
friction
sliding bearing
wear
Opis:
W pracy przedstawiono wyniki badań liniowej intensywności zużycia Ih oraz gęstości pracy (energii) tarcia e* R[J/m3] wyznaczonych metodą analityczno doświadczalną. Badania przeprowadzono dla różnych materiałów panewek. Pomiar zużycia dokonywany był poprzez pomiar okrągłości w czterech przekrojach panewki oraz przez pomiar masy przed i po pracy w warunkach tarcia mieszanego. Wyniki przedstawiono w postaci tabel i wykresów.
This paper presents the results of investigation into the wear linear intensity Ih and the density (energy) of friction e* R[J/m3] that were determined by means of experimentalanalytical method. The investigations were carried out for different materials of sleeves. Two methods were applied to the wear measurement, i.e. by measuring the roundness in four crosssections of sleeve as well as by the measurement of the mass before and after the operation in the conditions of mixed friction. The results are given in the form of tables and diagrams.
Źródło:
Acta Mechanica et Automatica; 2009, 3, 1; 84-97
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructural, Corrosion and Abrasive Characteristics of Titanium Matrix Composites
Autorzy:
Figiel, P.
Garbiec, D.
Biedunkiewicz, A.
Biedunkiewicz, W.
Kochmański, P.
Wróbel, R.
Powiązania:
https://bibliotekanauki.pl/articles/354537.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
titanium matrix composite
SPS
corrosion resistance
sliding wear
Opis:
Commercially pure titanium is less expensive, generally more corrosion resistant and lower in strength than its alloys, and is not heat-treatable. The use of Ti and its alloys as construction materials under severe friction and wear conditions is limited due to their poor tribological properties. Nevertheless, proper addition of hard ceramic particles into Ti and its alloys has proved to be an efficient way to enhance their mechanical and wear properties. Our purpose in this work was to analyze the corrosion, tribocorrosion, mechanical and morphological effects of combining titanium carbide with titanium metal, to create a unique composite via spark plasma sintering technique (SPS). Composites with different mass percentage (1, 5, 10, 15 and 20 wt %) of ceramic phase were produced. The samples of pure Ti and Ti-6Al-4V alloy were also tested, as a reference. These composites were examined for mechanical properties and corrosion resistance in an environment similar to the human body (Ringer’s solution). Open circuit potential (OPC) and anodic polarization measurements were performed. The properties of titanium composites reinforced with micro- and nanocrystalline TiC powders were compared. It was stated that wear properties were significantly improved with increasing amount of TiC in matrix, especially in the case of nanocrystalline reinforcement. In terms of corrosion resistance, the composites showed slightly worse properties compared to pure titanium and Ti-6Al-4V alloy.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 4; 2051-2059
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Backstepping sliding mode controller improved with fuzzy logic: Application to the quadrotor helicopter
Autorzy:
Zeghlache, S.
Saigaa, D.
Harrag, A.
Kara, K.
Bouguerra, A.
Powiązania:
https://bibliotekanauki.pl/articles/229480.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fuzzy sliding mode
backstepping
quadrotor helicopter
dynamic modeling
Opis:
n this paper we present a new design method for the fight control of an autonomous quadrotor helicopter based on fuzzy sliding mode control using backstepping approach. Due to the underactuated property of the quadrotor helicopter, the controller can move three positions (x;y; z) of the helicopter and the yaw angle to their desired values and stabilize the pitch and roll angles. A first-order nonlinear sliding surface is obtained using the backstepping technique, on which the developed sliding mode controller is based. Mathematical development for the stability and convergence of the system is presented. The main purpose is to eliminate the chattering phenomenon. Thus we have used a fuzzy logic control to generate the hitting control signal. The performances of the nonlinear control method are evaluated by simulation and the results demonstrate the effectiveness of the proposed control strategy for the quadrotor helicopter in vertical flights.
Źródło:
Archives of Control Sciences; 2012, 22, 3; 315-342
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The research of rotating sets in turbochargers, the influence of relative width of sliding bearings with a floating ring on static and dynamic properties
Autorzy:
Cygnar, M.
Aleksander, M.
Mazurkow, A.
Budzik, G.
Powiązania:
https://bibliotekanauki.pl/articles/242325.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
turbocharger
rotating unit
sliding bearing with a floatin
Opis:
This work is the continuation of the research concerning the dynamic model of a rotating set in turbocharger. In this model masses of rotors and a shaft have been modelled as concentrated masses. The rotating set has been propped on two supports forming lateral sliding bearings with a floating ring bearing. Each bearing is designed including floating ring bearing mass. The shaft of a rotating set spins at angular velocity omega 1 whereas a floating ring bearing spins at angular speed omega 2. A mathematical model constitutes a system of differential equations, mutually coupled. The mathematical model has been solved by determining: acceleration, velocity and displacement in each knot. The paper shows the crucial influence of a bearing relative clearance on static and dynamic properties of a rotating set in a turbocharger. The authors suggest that the rotating set works stably only in these cases as for given parameters, we choose properly oil films' geometry. In the conclusion, the authors formulate proposal that might be usefulfor the designers who deal with these types of bearings. Especially, the mathematical model o f a turbocharger rotating set, work parameters of bearing knots, researches of static and dynamic properties are presented in the paper.
Źródło:
Journal of KONES; 2009, 16, 2; 91-96
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tribological properties of sliding pairs with surface layer containing boron under mixed friction conditions
Autorzy:
Lubas, J.
Powiązania:
https://bibliotekanauki.pl/articles/242626.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
surface treatment
wear
sliding friction
boron
bearing alloy
Opis:
The aim of the present work is to determine the influence of surface layers containing boron on the friction parameters in sliding pairs under mixed friction conditions. The tribological evaluation included three production methods of surface layers with boron; pack boronizing, laser boronizing, and TiB2 coating deposited on 46Cr2 steel. Modified surface layers of ring specimens with 46Cr2 steel were matched under test conditions with a counterpart made from AlSn20 bearing alloy. Tested sliding pairs were lubricated with 5W/40 Lotos synthetic engine oil. The applied modification technologies of the surface layer of steel allowed for obtaining construction materials with predetermined tribological characteristics required for the elements of sliding pairs working undermixed friction conditions. The results showed differences in the wear of bearing alloy, as the effect of the interaction between the cooperating surface layers and of the physiochemical changes of their surfaces, induced by external forces. The TiB2 coating generated the highest friction resistance and bearing alloy wear. The pack borided surface layer reduces the friction coefficient, the moment during the start-up of the frictional pair and the wear of the bearing material. The analysis of the surface layer indicated that the content of aluminum on pack borided ring specimens reached 21%, and on the TiB2 coating, it exceeded 8%.
Źródło:
Journal of KONES; 2013, 20, 1; 185-192
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of main design parameters of ship propeller shaft water-lubricated bearings on their properties
Autorzy:
Litwin, W.
Powiązania:
https://bibliotekanauki.pl/articles/259397.pdf
Data publikacji:
2010
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
water lubrictaed bearings
stern tube bearings
sliding bearings
Opis:
In recent years more and more frequently can be met ships in which propeller shaft water-lubricated polymer bearings have been applied. It results from their simplicity and associated relatively low initial and operational cost as compared with the complex classical sealed system based on oil-lubricated bearings. It is worth mentioning that the water-lubricated bearings are also environmentally friendly as no risk of pollution with lubricating oil used in classical systems, is involved. Design procedure of bearings in question based on materials made available by producers is relatively simple. However it turns out that choice of an appropriate sliding material, clearance value and optimum arrangement of lubricating grooves may greatly influence bearing’s properties. As results from the performed research investigations, bearing of the kind is a highly sensitive unit. Problems of choosing a suitable bearing clearance, designing an optimum bush geometry, selecting a proper bush material are crucial for life time of the bearing. In particular the problem is in forming hydrodynamical properties of bearing as owing to its operation in the fluid friction regime durability of bearings, the very responsible units of propulsion transmission system, can be greatly extended.
Źródło:
Polish Maritime Research; 2010, 4; 39-45
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dry Sliding Wear Behavior of Boron-Doped AISI 1020 Steels
Autorzy:
Aktas, B.
Balak, V.
Carboga, C.
Powiązania:
https://bibliotekanauki.pl/articles/1031623.pdf
Data publikacji:
2017-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
dry sliding wear
AISI 1020 steel
boron
friction
Opis:
In the present study, the wear properties of AISI 1020 steels produced by a casting process with different boron contents were investigated, using a pin-on-disc tribometer under dry sliding conditions. The friction coefficients of undoped AISI 1020 steel, 0.002 and 0.01 wt% boron-doped samples were 0.33, 0.27, and 0.32, respectively. The addition of boron into AISI 1020 steel led to a decrease in the friction coefficient, due to the lubricating effect of boron; X-ray diffraction showed that both Fe₂B and FeB phases are present in the boron-doped samples, both of which cause this lubrication. The wear test results also showed that the wear rate of the 0.002 wt% boron-doped AISI 1020 sample decreased compared to the undoped AISI steel, and then increased in the 0.01 wt% boron sample. Therefore, the wear resistance of AISI 1020 steel is increased with the addition of small amounts of boron. Scanning electron microscopy results indicated that the characteristic wear mechanism for the boron-doped sample surfaces was plastic deformation and mild abrasive wear; for undoped AISI 1020 steel, cracking and spalling were observed instead.
Źródło:
Acta Physica Polonica A; 2017, 132, 3; 455-457
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
ANFIS-based PID continuous sliding mode controller for robot manipulators in joint space
Autorzy:
Elawady, Wael M.
Asar, Mohammed F.
Sarhan, Amany M.
Powiązania:
https://bibliotekanauki.pl/articles/1839129.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
PID
continuous sliding mode control
ANFIS
uncertainties
robot
Opis:
This paper presents a feasible design for a con- trol algorithm to synthesize an adaptive neuro-fuzzy inference system-based PID continuous sliding mode control system (ANFIS- PIDCSMC) for adaptive trajectory tracking control of the rigid robot manipulators (RRMs) in the joint space. First, a PID sliding mode control algorithm with sliding surface dynamics-based continuous proportional-integral (PI) control action (PIDSMC-SSDCPI) is presented. The global stability conditions are formulated in terms of Lyapunov full quadratic form such that the robot system output can track the desired reference output. Second, to increase the control system robustness, the PI control action in the PIDSMC- SSDCPI controller is supplanted by an ANFIS control signal to provide a control approach that can be termed adaptive neuro-fuzzy inference system-based PID continuous sliding mode control system (ANFIS-PIDCSMC). For the proposed control algorithm, numerical simulations using the dynamic model of RRM with uncertainties and external disturbances show high quality and effectiveness of the adopted control approach in high-speed trajectory tracking control problems. The simulation results that are compared with the results, obtained for the traditional controllers (standalone PID and traditional sliding mode controller (TSMC)), illustrate the fact that the tracking control behavior of the robot system achieves acceptable tracking performance.
Źródło:
Control and Cybernetics; 2019, 48, 4; 525-555
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of sliding friction of WC-Co composite on particleboard
Autorzy:
Wilkowski, Jacek
Barlak, Marek
Jałocha, Radosław
Werner, Zbigniew
Auriga, Alicja
Powiązania:
https://bibliotekanauki.pl/articles/2200135.pdf
Data publikacji:
2020
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
WC-Co composites
particleboard
sliding friction
surface roughness
Opis:
Analysis of sliding friction of WC-Co composite on particleboard. The paper presents the analysis of the coefficient of friction at the contact area between WC-Co composite and particleboard. The four types of WC-Co composite in the form of milling indexable knives for wood materials machining were tested. The tests were carried out on a linear reciprocating tribotester (pin-on-flat), where the sample was the clearance surface of WC-Co indexable knives and the counter-sample was made of three-layer particleboard. Before and after tribological tests, the surface roughness of tested knives was measured. The highest values of friction coefficient were obtained for the type UMG04 of cemented carbide - with nano size of WC grains and the lowest content of cobalt. The average coefficient of friction for selected types of WC-Co correlated with the average increase in surface roughness (the roughness parameter Ry).
Analiza tarcia ślizgowego kompozytu WC-Co w kontakcie z płytą wiórową. Artykuł przedstawia analizę współczynnika tarcia na styku kompozyt WC-Co i płytay wiórowaej. Przebadano cztery rodzaje kompozytu WC-Co w postaci frezarskich noży wymiennych do obróbki materiałów drzewnych. Badania przeprowadzono na tribotesterze typu „trzpień po płaszczyźnie”, gdzie próbką była powierzchnia przyłożenia noża wymiennego WC-Co, a przeciwpróbką był trzpień wykonany z trójwarstwowej płyty wiórowej. Przed i po badaniach tribologicznych dokonano pomiaru chropowatości powierzchni badanych noży. Najwyższe wartości współczynnika tarcia uzyskano dla rodzaju węglika UMG04 o najdrobniejszych ziarnach WC i najniższej zawartości kobaltu. Średni współczynnik tarcia dla poszczególnych rodzajów WC-Co korelował ze średnim przyrostem chropowatości wyrażonej parametrem Ry.
Źródło:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology; 2020, 111; 60--67
1898-5912
Pojawia się w:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sliding mode observers for fault identification in linear systems not satisfying matching and minimum phase conditions
Autorzy:
Zhirabok, Alexey
Zuev, Alexander
Filaretov, Vladimir
Shumsky, Alexey
Powiązania:
https://bibliotekanauki.pl/articles/1409401.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
linear systems
faults
identification
disturbances
sliding mode observer
Opis:
The paper studies the fault identification problem for linear control systems under the unmatched disturbances. A novel approach to the construction of a sliding mode observer is proposed for systems that do not satisfy common conditions required for fault estimation, in particular matching condition, minimum phase condition, and detectability condition. The suggested approach is based on the reduced order model of the original system. This allows to reduce complexity of sliding mode observer and relax the limitations imposed on the original system.
Źródło:
Archives of Control Sciences; 2021, 31, 2; 253-266
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of overset mesh approach in the investigation of the Savonius wind turbines with rigid and deformable blades
Autorzy:
Marchewka, Emil
Sobczak, Krzysztof
Reorowicz, Piotr
Obidowski, Damian Stanisław
Jóźwik, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/1955051.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
CFD
savonius
deformable blade
overset mesh
sliding mesh
Opis:
Machines utilising renewable energy constantly undergo research aimed at raising their efficiency. One of them is a Savonius wind turbine, where scientists propose adjustments to improve its aerodynamic properties. At present, their assessment is usually performed by means of transient computational fluid dynamics simulations with two- or threedimensional models. In this paper, the overset (chimera) mesh approach was applied to investigate the performance of a Savonius wind turbine equipped with deformable blades. They were continuously deformed during rotation by a dedicated mechanism to increase a positive torque of the advancing blade, and meanwhile, decrease a negative torque of the returning blade. A quasi-two-dimensional model with a two-way fluid-structure interaction method was applied, where the structural solver determined blade deflection caused by the predefined deformation mechanism and aerodynamic loads, whereas the coupled computational fluid dynamics solver determined the transient flow. The deformable blades rotor performance was calculated and compared with a conventional rigid Savonius turbine, both simulated using the overset mesh approach. The average value of the power coefficient achieved a 55% rise in the case of deformable blades turbine. Additionally, to validate the overset method, its results were compared with the classical sliding mesh method for a conventional rigid rotor.
Źródło:
Archives of Thermodynamics; 2021, 42, 4; 201-216
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fractal Analysis of Noise Signals of Sampo and John Deere Combine Harvesters in Operational Conditions
Autorzy:
Boroujeni, Farzad Mahdiyeh
Maleki, Ali
Powiązania:
https://bibliotekanauki.pl/articles/176317.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
sound
combine
fractal dimension
engine speed
sliding window
Opis:
Combine harvesters are the source a large amount of noise in agriculture. Depending on different working conditions, the noise of such machines can have a significant effect on the hearing conditio of drivers. Therefore, it is highly important to study the noise signals caused by these machines and find solutions for reducing the produced noise. The present study was carried out is order to obtain the fractal dimension (FD) of the noise signals in Sampo and John Deere combine harvesters in different operational conditions. The noise signals of the combines were recorded with different engine speeds, operational conditions, gear states, and locations. Four methods of direct estimations of the FD of the waveform in the time domain with three sliding windows with lengths of 50, 100, and 200 ms were employed. The results showed that the Fractal Dimension/Sound Pressure Level [dB] in John Deere and Sampo combines varied in the ranges of 1.44/96.8 to 1.57/103.2 and 1.23/92.3 to 1.51/104.1, respectively. The cabins of Sampo and John Deere combines reduced and enhanced these amounts, respectively. With an increase in the length of the sliding windows and the engine speed of the combines, the amount of FD increased. In other words, the size of the suitable window depends on the extraction method of calculating the FD. The results also showed that the type of the gearbox used in the combines could have a tangible effect on the trend of changes in the FD.
Źródło:
Archives of Acoustics; 2019, 44, 1; 89-98
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gaussian process dynamic modeling and backstepping sliding mode control for magnetic levitation system of maglev train
Autorzy:
Sun, Yougang
Wang, Sumei
Lu, Yang
Xu, Junqi
Powiązania:
https://bibliotekanauki.pl/articles/2086959.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
maglev train
Gaussian process
sliding mode control
parameter perturbations
Opis:
The maglev trains are strongly nonlinear and open-loop unstable systems with external disturbances and parameters uncertainty. In this paper, the Gaussian process method is utilized to get the dynamic parameters, and a backstepping sliding mode controller is proposed for magnetic levitation systems (MLS) of maglev trains. That is, for a MLS of a maglev train, a nonlinear dynamic model with accurate parameters is obtained by the Gaussian process regression method, based on which a novel robust control algorithm is designed. Specifically, the MLS is divided into two sub-systems by a backstepping method. The inter virtual control inputs and the Lyapunov function are constructed in the first sub-system. For the second sub-system, the sliding mode surface is constructed to fulfil the design of the whole controller to asymptotically regulate the airgap to a desired trajectory. The stability of the proposed control method is analyzed by the Lyapunov method. Both simulation and experimental results are included to illustrate the superior performance of the presented method to cope with parameters perturbations and external disturbance.
Źródło:
Journal of Theoretical and Applied Mechanics; 2022, 60, 1; 49--62
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stability analysis of sliding-mode feedback control
Autorzy:
Clarke, F. H.
Vinter, R. B.
Powiązania:
https://bibliotekanauki.pl/articles/970887.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
sliding-mode control
discontinuous control
Lyapunov functions
stabilization
robustness
Opis:
This paper provides new analytic tools leading to the first rigorous stability and robustness analysis of sliding-mode feedback controllers. Unrestrictive conditions are given, under which these controllers are stabilizing in the presence of large disturbances, conditions invoke the existence of two Lyapunov-type functions, the first associated with passage to the sliding set in finite time, and the second with convergence to the desired state. In this approach, account is taken, from the outset, of implementational constraints. We provide a framework for establishing stability and robustness of the closed-loop system, for a variety of implementation schemes. We illustrate our results by means of two examples of the type frequently encountered in the sliding-mode literature.
Źródło:
Control and Cybernetics; 2009, 38, 4A; 1169-1192
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hierarchical sliding mode control for a class of SIMO under-actuated systems
Autorzy:
Qian, D.
Yi, J.
Zhao, D.
Powiązania:
https://bibliotekanauki.pl/articles/971008.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
control approaches
control applications
sliding mode control
underactuated systems
Opis:
A hierarchical sliding mode control approach is proposed for a class of SIMO under-actuated systems. This class of under-actuated systems is made up of several subsystems. Based on this physical structure, the hierarchical structure of the sliding surfaces is designed as follows. At first, the sliding surface of every subsystem is defined. Then the sliding surface of one subsystem is defined as the first layer sliding surface. The first layer sliding surface is used to construct the second layer sliding surface with the sliding surface of another subsystem. This process continues till the sliding surfaces of the entire subsystems are included. According to the hierarchical structure, the total control law is deduced by the Lyapunov theorem. In theory, the asymptotic stability of the entire system of sliding surfaces is proven and the parameter boundaries of the subsystem sliding surfaces are given. Simulation results show the feasibility of this control method through two typical SIMO under-actuated systems.
Źródło:
Control and Cybernetics; 2008, 37, 1; 159-175
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of grain dust on the friction factor in sliding kinematic pairs of plastic - steel
Autorzy:
Szefler, J.
Weiner, W.
Powiązania:
https://bibliotekanauki.pl/articles/24401.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
grain-feed product
corn
sliding factor
dust
grain dust
Źródło:
International Agrophysics; 1999, 13, 4
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Linear Speed Control for Multi-Machine system Using Fuzzy-Sliding Mode
Autorzy:
Bouchiba, B.
Hazzab, A.
Glaoui, H.
Med-Karim, F.
Bousserhane, I. K.
Sicard, P.
Powiązania:
https://bibliotekanauki.pl/articles/384749.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
multi-motors system
fuzzy logic
sliding mode control
MIMO
Opis:
In this contribution, a control scheme based on multi input multi output Fuzzy Sliding Mode control (MIMOFSMC) for linear speed regulation of multi-motors system is proposed. Once the decoupled model of the multi- motors system is obtained, a smooth control function with a threshold was chosen to indicate how far the state from to the sliding surface is. However, the magnitude of this control function depends closely on the upper bound of uncertainties, and this generates chattering. So, this magnitude has to be chosen with great care to obtain high performances. Usually the upper bound of uncertainties is difficult to known before motor operation, so, a Fuzzy Sliding Mode controller is investigated to solve this difficulty; a simple Fuzzy inference mechanism is used to reduce the chattering phenomenon by simple adjustments. A simulation study is carried out and shows that the proposed controller has great potential for use as an alternative to the conventional sliding mode contro.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2012, 6, 1; 3-7
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ wybranych parametrów eksploatacyjnych mikrołożysk ślizgowych na stan powierzchni elementów trących
The influence of selected process parameters on surfaces properties of the friction elements
Autorzy:
Łupicka, O.
Maciejewski, I.
Lapitskaya, V.
Kuznetsova, T.
Powiązania:
https://bibliotekanauki.pl/articles/313720.pdf
Data publikacji:
2017
Wydawca:
Instytut Naukowo-Wydawniczy "SPATIUM"
Tematy:
łożysko ślizgowe
zużycie ścierne
SEM
sliding bearing
abrasive wear
Opis:
W pracy przedstawiono wyniki badań wpływu wybranych parametrów procesu eksploatacji mikro-łożysk ślizgowych, tj. czasu t [h] oraz obciążenia L [N] na stan powierzchni współpracujących elementów. Topografię i analizę powierzchni oceniano przy użyciu elektronowego mikroskopu skaningowego SEM oraz mikroskopu sił atomowych AFM. Uzyskane wyniki potwierdziły istotny wpływ badanych parametrów na chropowatość powierzchni oraz pozwoliły na dokonanie oceny stopnia zużycia badanych elementów w skali mikro.
The paper presents the results of investigations of the influence of selected process parameters on surface properties of the sliding micro-bearing, i.e. time t [h] and load L [N]. The obtained results confirmed the influence of both parameters on the surface and makes possible to evaluate the wear in micro scale.
Źródło:
Autobusy : technika, eksploatacja, systemy transportowe; 2017, 18, 6; 895-899, CD
1509-5878
2450-7725
Pojawia się w:
Autobusy : technika, eksploatacja, systemy transportowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Friction lining coefficient of the drive friction pulley
Autorzy:
Krešák, Jozef
Peterka, Pavel
Ambriško, Ľubomír
Mantič, Martin
Powiązania:
https://bibliotekanauki.pl/articles/1841748.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
hoisting rope
friction pulley
friction lining
sliding friction coefficient
Opis:
Mine hoisting KOEPPE system or friction hoist winch work with traction pulley, the pulley rim grooves are lined. Lining has to provide a higher friction coefficient between the rope and the traction pulley. The constructors of mine hoisting machines require from the manufacturers a guaranteed appropriate and stabile value of a friction coefficient at different pressures between a rope and a friction lining under different external conditions (drought, moisture, icing, etc.). The paper presents processed measurements performed on the six samples of the friction lining (G1-G6) made of rubber and the sample of the standard used friction lining (K25). The samples (G1-G6) differ in the chemical composition of the rubber. Due to the confidentiality of the material composition of the friction linings the hardness of the lining material as a discriminator was chosen. The measured values of the friction coefficient of the rubber friction lining samples were compared with the values of the friction coefficient of the friction lining (K25) usually mounted on friction lining pulley.
Źródło:
Eksploatacja i Niezawodność; 2021, 23, 2; 338-345
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two cascaded and extended kalman filters combined with sliding mode control for sustainable management of marine fish stocks
Autorzy:
Benz, Katharina
Rech, Claus
Mercorelli, Paolo
Sergiyenko, Oleg
Powiązania:
https://bibliotekanauki.pl/articles/1837383.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
Lotka‐Volterra model
sliding mode control
Extended Kalman Filter
Opis:
This paper deals with a possible approach to controlling marine fish stocks using the prey‐predator model described by the Lotka‐Volterra equations. The control strategy is conceived using the sliding mode control (SMC) approach which, based on the Lyapunov theorem, offers the possibility to track desired functions, thus guaranteeing the stability of the controlled system. One of the most important aspects of this model is the identification of some parameters which characterizes the model. In this work two cascaded and Extended Kalman Filters (EKFs) are proposed to estimate them in order to be utilized in SMC. This approach can be used for sustainable management of marine fish stocks: through the developed algorithm, the appropriate number of active fishermen and the suitable period for fishing can be determined. Computer simulations validate the proposed approach.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2020, 14, 3; 28-35
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Indirect torque observer-based sensor-less efficient control of bearingless switched reluctance motor using global sliding mode and square currents control method
Autorzy:
Rao, Pulivarthi Nageswara
Devarapalli, Ramesh
Marquez, Fausto Pedro Garcia
Kumar, G. V. Nagesh
Mohammadi-Ivatloo, Behnam
Powiązania:
https://bibliotekanauki.pl/articles/1409027.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
bearingless
global sliding mode
efficient: maintenance
safety
torque ripple
Opis:
The Bearingless Switched Reluctance Motor (BSRM) is a new technology motor, which overcomes the problems of maintenances required associated with mechanical contacts and lubrication of rotor shaft effectively. In addition, it also improves the output power developed and rated speed. Hence, the BSRM can achieve high output power and super high speed with less size and cost. It has a considerable ripple in the net-torque due to its critical non-linearity and the salient pole structures of both stator and rotor poles. The resultant torque ripple, especially in these motors, causes the more vibrations and acoustic noises will affects the levitated rotor safety also. Practically at high-speed operations, the accurate measurement of the rotor position is complicated for conventional mechanical sensors. A new square currents control with global sliding mode control based sensorless torque observer is proposed to minimize the torque ripple and achieve a smooth, robust operation without using any mechanical sensors. The proposed controller is designed based on the error between the reference and measured torque values. The sliding mode torque observer measures the torque from the actual phase voltages, currents, and look-up tables. The simulation model has been modelled to validate the proposed methodology. From the simulation outputs, it is clear that the reduction of torque ripple by the proposed method shows improved than the conventional sliding mode controller. The overall system is more robust to the external disturbances, and it also gets efficient torque profile.
Źródło:
Archives of Control Sciences; 2021, 31, 1; 53-80
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Volnistost poverkhnosti pri obkatyvanijj tel vrashhenija polikami
Waviness of surface at rolling-off of bodies of rotation rollers
Autorzy:
Butakov, B.
Artyukh, V.
Powiązania:
https://bibliotekanauki.pl/articles/77575.pdf
Data publikacji:
2013
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
rolling
waviness
sliding friction
mechanism
roller loading
friction force
Opis:
Formulated and reason appearance of waviness is experimentally grounded at a rolling toroobraznymi rollers is oscillation of effort of rolling from the presence of large forces of sliding friction in the mechanism of loading of roller.
Źródło:
Motrol. Motoryzacja i Energetyka Rolnictwa; 2013, 15, 2
1730-8658
Pojawia się w:
Motrol. Motoryzacja i Energetyka Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ship trajectory tracking control system design based on sliding mode control algorithm
Autorzy:
Liu, Y.
Bu, R.
Gao, X.
Powiązania:
https://bibliotekanauki.pl/articles/259621.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
LOS
ship trajectory
tracking control system
sliding mode control
Opis:
The paper reports the design and tests of the planar autopilot navigation system in the three-degree-of-freedom (3-DOF) plane (surge, sway and yaw) for a ship. The aim of the tests was to check the improved maneuverability of the ship in open waters using the improved nonlinear control algorithm, developed based on the sliding mode control theory for the ship-trajectory tracking problem of under-actuated ships with static constraints, actuator saturation, and parametric uncertainties. With the integration of the simple increment feedback control law, the dynamic control strategy was developed to fulfill the under-actuated tracking and stabilization objectives. In addition, the LOS (line of sight) guidance system was applied to control the motion path, whereas the sliding mode controller was used to emulate the rudder angle and propeller rotational speed control. Firstly, simulation tests were performed to verify the validity of the basic model and the tracking control algorithm. Subsequently, full scale maneuverability tests were done with a novel container ship, equipped with trajectory tracking control and sliding mode controller algorithm, to check the dynamic stability performance of the ship. The results of the theoretical and numerical simulation on a training ship verify the invariability and excellent robustness of the proposed controller, which: effectively eliminates system chattering, solves the problem of lateral drift of the ship, and maintains the following of the trajectory while simultaneously achieving global stability and robustness.
Źródło:
Polish Maritime Research; 2018, 3; 26-34
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quasi-Sliding Mode Control of Discrete-Time Systems
Autorzy:
Bartoszewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/908266.pdf
Data publikacji:
1999
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
sterowanie
system dyskretny
sliding-mode control
discrete-time systems
Opis:
A reaching law approach to the design of discrete-time quasi-sliding mode control systems is considered. First the required position of the system representative point with reference to the sliding plane is specified, and then novel control strategies, which drive the system in such a way that the position actually changes according to the specification, are proposed. The strategies are linear and consequently the undesirable chattering and high-frequency switching between different values of the control signal are avoided. Furthermore, the state of the controlled system is driven to the narrowest possible band around the sliding plane. The strategies, when compared with previously published results, are simpler and they guarantee favourable performance of the controlled systems while using essentially reduced control effort.
Źródło:
International Journal of Applied Mathematics and Computer Science; 1999, 9, 4; 801-810
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on beam supply control strategy based on sliding mode control
Autorzy:
Zhang, Hao
Dong, Haiying
Zhang, Baoping
Wu, Tong
Chen, Changwen
Powiązania:
https://bibliotekanauki.pl/articles/141014.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
beam supply
DC/DC converter
robustness
sliding mode control
Opis:
In the hybrid multiple H-bridge topology of beam supply, the load change of a DC/DC full-bridge converter can greatly affect the output voltage during onsite operation. An improved sliding mode control (SMC) strategy is thus proposed in this paper, where the rate of switching control is added to the law of system equivalent control to create a law that can realize a complete sliding mode control. Considering the special operating conditions of the load can have an influence on the performance of the controller, the impact of uncertainty existing in onsite conditions is suppressed with the proposed strategy utilized. The validity of the proposed strategy, finally, is verified by simulation, which proves the outperformance of the system in both robustness and dynamics.
Źródło:
Archives of Electrical Engineering; 2020, 69, 2; 349-364
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental evaluation of DLC/steel sliding contacts’ operational envelope
Doświadczalna ocena dopuszczalnych warunków eksploatacji dla ślizgowego skojarzenia DLC/stal
Autorzy:
Łubiński, J.
Wasilczuk, M
Powiązania:
https://bibliotekanauki.pl/articles/190091.pdf
Data publikacji:
2018
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
sliding friction testing
tribometer
distributed contact
sliding friction
resistance to wear
badania tarcia ślizgowego
tribometr
styk konforemny
tarcie ślizgowe
odporność na zużycie
Opis:
In an industrial project concerning sliding bearings, a sliding pair was selected of high alloy steel vs. industrial grade DLC coated high alloy steel as a basis for an innovative design of high performance sliding bearings lubricated with a synthetic oil for use in geared transmission units. The development process required credible data on the ultimate resistance of the sliding pair to very high contact stress. An experimental evaluation was undertaken in ring-on-ring contact with an incremental semi-steady state input parameters increase. Due to restrictions in time, economy, and manufacturing, the number of specimen sets available was limited. A flexible approach to specimen use and load/velocity/time combinations was employed to deliver required test results within the available resource limitations and at constantly updated project detailed goals.
Przedstawiono przebieg i wyniki badań tarcia ślizgowego skojarzenia próbek ze stali wysokostopowej z powłoką DLC do zastosowań przemysłowych naniesioną na jedną ze stron skojarzenia. Badania stanowiły część prac związanych z rozwojem łożysk ślizgowych o wysokiej obciążalności jednostkowej, przeznaczonych do pracy w warunkach smarowania syntetycznym olejem przekładniowym. W toku prac rozwojowych konieczne okazało się uzyskanie danych na temat maksymalnej odporności powłoki na uszkodzenia przy bardzo dużych obciążeniach jednostkowych. Doświadczenia przeprowadzono w skojarzeniu płaskim, pierścieniowym przy semistacjonarnym wymuszeniu obciążeniem. Z uwagi na ograniczenia czasowe, finansowe i technologiczne związane z ograniczonymi możliwościami wytwarzania próbek, prace badawcze zrealizowano przy bardzo ograniczonej liczbie skojarzeń. Wykorzystano elastyczne podejście do wykorzystania próbek oraz zastosowanych w testach kombinacji obciążenie/prędkość/czas, aby zgromadzić dla partnera przemysłowego potrzebne wyniki w ramach dostępnych środków i przy ciągłych korektach szczegółowych celów podczas prowadzenia prac.
Źródło:
Tribologia; 2018, 281, 5; 41-46
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Firefly algorithm optimization of manipulator robotic control based on fast terminal sliding mode
Autorzy:
Mallem, Ali
Douak, Fouzi
Benaziza, Walid
Bounouara, Asma
Powiązania:
https://bibliotekanauki.pl/articles/27314236.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
manipulator robotic
fast terminal sliding mode
firefly algorithm
Lyapunov stability
Opis:
In this paper a new algorithm of optimization in the field of manipulator robotic control is presented. The proposed control approach is based on fast terminal sliding mode control (FTSMC), in order to guarantee the convergence of the position articulations errors to zero in finite time without chattering phenomena, and the Firefly algorithm in order to generate the optimal parameters that ensure minimum reaching time and mean square error and achieve better performances. This ensures the asymptotic stability of the system using a Lyapunov candidate in the presence of disturbances. The simulations are applied on a two-link robotic manipulator with different tracking references by using Matlab/ Simulink. Results show the efficiency and confirm the robustness of the proposed control strategy.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2022, 16, 4; 44--52
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of the Wear Mechanism in Sliding Contact of Satelite Gears of a Hydraulic Motor
Ocena zużycia mechanizmu satelitowego w skojarzeniu ślizgowym wykorzystywanego w silniku hydraulicznym
Autorzy:
Bąkowski, H.
Powiązania:
https://bibliotekanauki.pl/articles/188603.pdf
Data publikacji:
2018
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
wear
sliding contact
hydraulic motor
zużycie
skojarzenie ślizgowe
silnik hydrauliczny
Opis:
The paper presents tests of the wear of selected elements of a hydraulic satellite engine in sliding contact. The tests were carried out on the tribotester T-05 in a roll-block system, taking into account the influence of the most important operational parameters determining the durability of the friction node in question. The performed tribological, metallographic and profilographometric studies allowed the comparison and evaluation of the mechanism of sliding contact wear in the laboratory stand and on the real object, which allows one to make far-reaching assumptions about the durability of the contact in question and its resistance to wear under various operating.
W pracy przedstawiono badania zużycia wybranych elementów hydraulicznego silnika satelitowego w skojarzeniu ślizgowym. Badania przeprowadzono na tribotesterze T-05 w układzie rolka-klocek, uwzględniając wpływ najważniejszych parametrów eksploatacyjnych decydujących o trwałości rozpatrywanego węzła tarcia. Przeprowadzone badania tribologiczne, metalograficzne i profilografometryczne pozwoliły na porównanie i ocenę mechanizmu zużywania skojarzenia ślizgowego na stanowisku laboratoryjnym i na obiekcie rzeczywistym, co pozwala wysuwać daleko idące przypuszczenia co do trwałości rozpatrywanego skojarzenia i jego odporności na zużycie w różnych warunkach eksploatacji.
Źródło:
Tribologia; 2018, 279, 3; 5-12
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A note on attractivity for the intersection of two discontinuity manifolds
Autorzy:
Difonzo, Fabio V.
Powiązania:
https://bibliotekanauki.pl/articles/1397339.pdf
Data publikacji:
2021
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
piecewise smooth systems
sliding motion
co-dimension 2
discontinuity manifold
Opis:
In piecewise smooth dynamical systems, a co-dimension 2 discontinuity manifold can be attractive either through partial sliding or by spiraling. In this work we prove that both attractivity regimes can be analyzed by means of the moments solution, a spiraling bifurcation parameter and a novel attractivity parameter, which changes sign when attractivity switches from sliding to spiraling attractivity or vice-versa. We also study what happens at what we call attractivity transition points, showing that the spiraling bifurcation parameter is always zero at those points.
Źródło:
Opuscula Mathematica; 2020, 40, 6; 685-702
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza korelacji wyników zmęczeniowych badań łożysk ślizgowych
Correlation analysis of results of plain bearing fatigue investigations
Autorzy:
Sikora, J.
Powiązania:
https://bibliotekanauki.pl/articles/387522.pdf
Data publikacji:
2009
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
łożysko ślizgowe
zmęczenie
standardy ISO
sliding bearing
ISO standards
tiring
Opis:
W pracy przedstawiono analizę korelacji wyników zmęczeniowych badań łożysk przeprowadzonych zgodnie z zaleceniami norm ISO. Przedmiotem analizy były wyznaczone graniczne wartości naprężeń obwodowych w warstwach ślizgowych panwi badanych w testerze SKMR-2 (zgodnym ze standardem ISO 7905/4) oraz w warunkach pełnego filmu smarowego na stanowiskach łożyskowych MWO i SMOK w Politechnice Gdańskiej.
A correlation analysis of results of plain bearing fatigue tests, that were performed in accordance with ISO standards, have been presented in the paper. Estimated boundary values of tangential stresses in surface layers of slide bearing bushes were objects of the analysis. The bushes were investigated in different devices: SKMR-2 fatigue tester (according to ISO 7905/4 standard) and MWO and SMOK bearing testing machines (under conditions of full fluid lubrication). It has been proved that the results of fatigue experiments performed on rigs of different pattern of load generation are not directly comparable though they demonstrate the same order of various bearing materials from the viewpoint of fatigue resistance.
Źródło:
Acta Mechanica et Automatica; 2009, 3, 2; 94-96
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Problemy eksploatacyjne oraz diagnostyka zakłóceń i awarii występujących w pracy maszyn elektrycznych z zestykiem ślizgowym
Operating problems and diagnostics of disturbances and failures occuring in the operation of electrical machines with sliding contact
Autorzy:
Małota, K.
Powiązania:
https://bibliotekanauki.pl/articles/1368757.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Napędów i Maszyn Elektrycznych Komel
Tematy:
diagnostyka zakłóceń
maszyny elektryczne
zestyk ślizgowy
electrical machines
sliding contact
Opis:
Technical devices that use electric machines with brush sliding contact stillrepresent a large part of utilized drives. In wide variety of applications for carbon brushes such as mining, vehicles with battery drive, aerospace, cosmonautics,power engineering, traction, industry, and many other areas, proper selection of the sliding contact elements, mainly carbon electric brushes, is a prerequisite for failsafe work, to obtain the Best performance and lowest operating costs. In recent years, due to the generational exchange of technical personnel in industry, more and more often one does not see the importance of maintaining a professional approach to the technical efficiency of electrical machines with sliding contacts. In this study we present few selected fromrecent years, typical operational problems,identified by the company's specialists from Elektrocarbon in Tarnowskie Gory. Often, problems arose from failure tothe technical rules of proper selection of replacement part to sliding contact: brush holder or brush. In this study have been discussed following examples of failure and disruption of machines that have occurred in: asynchronous slip-ring motors used in conveyor belt drives in coal open-pit mines, the comutatorgenerator supplying winder in a coal mine, the railway engine of modernized electric locomotives. In each of these cases method of how problems were successfully solved was presented.
Źródło:
Maszyny Elektryczne: zeszyty problemowe; 2012, 1, 94; 87-91
0239-3646
2084-5618
Pojawia się w:
Maszyny Elektryczne: zeszyty problemowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of four state observer design algorithms for MIMO system
Autorzy:
Vinodh, K. E.
Jovitha, J
Ayyappan, S.
Powiązania:
https://bibliotekanauki.pl/articles/229209.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
luenberger observer
Kalman observer
unknown input observer
sliding mode observer
Opis:
A state observer is a system that models a real system in order to provide an estimate of the internal state of the system. The design techniques and comparison of four different types of state observers are presented in this paper. The considered observers include Luenberger observer, Kalman observer, unknown input observer and sliding mode observer. The application of these observers to a Multiple Input Multiple Output (MIMO) DC servo motor model and the performance of observers is assessed. In order to evaluate the effectiveness of these schemes, the simulated results on the position of DC servo motor in terms of residuals including white noise disturbance and additive faults are compared.
Źródło:
Archives of Control Sciences; 2013, 23, 2; 243-256
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza uszkodzeń styków ślizgowych kompozytowych (Cu-Mo) stosowanych w transporcie kopalnianym
Failure analysis of sliding contacts made of cu-mo composition used in mining transportation
Autorzy:
Miedziński, B.
Okraszewski, Z.
Habrych, M.
Wandzio, J.
Minakova, R.
Timofyeeva, I.
Isayeva, I.
Zatovsky, V.
Francevic, I.
Powiązania:
https://bibliotekanauki.pl/articles/185902.pdf
Data publikacji:
2010
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technik Innowacyjnych EMAG
Tematy:
awaria
przyczyny awarii
styk kompozytowy
energy lost
failure
sliding contact
Opis:
W artykule przedstawiono i przedyskutowano wyniki analizy uszkodzeń styków kompozytowych Cu-Mo wykorzystywanych w układach transportu kopalnianego zasilanego prądem stałym. Na podstawie analizy morfologii powierzchni stykowych oraz wyników badań makro- i mikrostruktury obszarów zestyków uszkodzonych sformułowano wnioski odnośnie przyczyn zaistniałych uszkodzeń.
Paper presents and discusses the results of failure analysis of Cu-Mo composition used as a material in sliding power contacts DC for mining transportation. On the basis of the investigated results of the contact surface morphology and inspection of macro and microstructure of degradated areas the conclusions on reasons of the contact degradations are formulated.
Źródło:
Mechanizacja i Automatyzacja Górnictwa; 2010, R. 48, nr 4, 4; 41-48
0208-7448
Pojawia się w:
Mechanizacja i Automatyzacja Górnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmiana położenia układu odwróconego wahadła przy użyciu sterowania ślizgowego
Position changing of inverted pendulum system using a sliding mode control
Autorzy:
Tomera, M.
Powiązania:
https://bibliotekanauki.pl/articles/268605.pdf
Data publikacji:
2014
Wydawca:
Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Tematy:
sterowanie ślizgowe
LQR
odwrócone wahadło
sliding mode control
inverted pendulum
Opis:
W referacie przedstawione zostało sterowanie ślizgowe zastosowane do zmiany położenia wózka w układzie odwróconego wahadła. Obiekt sterowania jest nieliniowy, o dwóch stopniach swobody (kąt ustawienia wahadła i pozycja wózka) i jednym wejściu (siła przyłożona do wózka). Zadanie sterowania polega na takim przemieszczaniu położenia wózka, aby wraz z jego zmianami, pręt wahadła balansował w położeniu pionowym i nie przewrócił się. Model matematyczny obiektu składa się z czterech nieliniowych równań stanu. Sterowanie ślizgowe zazwyczaj stosowane jest do obiektów drugiego rzędu, zapisywanych w postaci zmiennych fazowych. Dlatego też w przypadku układu odwróconego wahadła konieczna była dekompozycja problemu i zastosowane zostało dwuwarstwowe sterowanie ślizgowe. W części równoważnej sterowania rozważone zostały regulatory: liniowo-kwadratowy (LQR) i proporcjonalno-całkującoróżniczkujący (PID), które są powszechnie stosowane do sterowania procesami dynamicznymi. Uzyskane układy sterowania ślizgowego są odporne na wpływ działających zakłóceń. Wyniki badań symulacyjnych pokazują efektywność pracy zaproponowanych struktur układów sterowania.
The paper presents sliding mode control, which was used to change the position of the cart in the inverted pendulum system. The plant of control is non-linear, with two degrees of freedom (the angle of the pendulum and the position of the cart) and one input (force applied to the cart). The task is to control the movement of the cart position to get along with his changes, balancing the pendulum rod in the upright position. The mathematical model of the object consists of four nonlinear equations of state. Sliding mode control is normally applied to the second-order systems, presented in the canonical form. Therefore, in the case of an inverted pendulum system, the decomposition of the problem was necessary and two-layer sliding mode control was applied. In the equivalent part of the control, two controllers were considered: linear quadratic regulator (LQR) and Proportional-Integral-Derivative (PID), which are commonly used to control dynamic processes. The resulting sliding mode control systems are robust to the influence of disturbance input. The results of simulation studies show the effectiveness of the work of the proposed structures of control systems.
Źródło:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2014, 40; 119-126
1425-5766
2353-1290
Pojawia się w:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Motion control and collision avoidance algorithms for unmanned surface vehicle swarm in practical maritime environment
Autorzy:
Zhuang, Jiayuan
Zhang, Lei
Qin, Zihe
Sun, Hanbing
Wang, Bo
Cao, Jian
Powiązania:
https://bibliotekanauki.pl/articles/260012.pdf
Data publikacji:
2019
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
USV
swarm control
collision avoidance
sliding mode
artificial potential field
Opis:
The issue of controlling a swarm of autonomous unmanned surface vehicles (USVs) in a practical maritime environment is studied in this paper. A hierarchical control framework associated with control algorithms for the USV swarm is proposed. In order to implement the distributed control of the autonomous swarm, the control framework is divided into three task layers. The first layer is the tele-operated task layer, which delivers the human operator’s command to the remote USV swarm. The second layer deals with autonomous tasks (i.e. swarm dispersion, or avoidance of obstacles and/or inner-USV collisions), which are defined by specific mathematical functions. The third layer is the control allocation layer, in which the control inputs are designed by applying the sliding mode control method. The motion controller is proved asymptotically stable by using the Lyapunov method. Numerical simulation of USV swarm motion is used to verify the effectiveness of the control framework.
Źródło:
Polish Maritime Research; 2019, 1; 107-116
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measuring Electromagnetic Emissions from Active Landslides
Autorzy:
Maniak, K.
Powiązania:
https://bibliotekanauki.pl/articles/309465.pdf
Data publikacji:
2015
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
electromagnetic emission
landslide
sliding-down force
slip planes
slope stability
Opis:
The paper describes the mechanism of electromagnetic emission generation in active landslides and measuring techniques. Special attention is given to electromagnetic emission fields. The author proposes an original system for measuring both continuous and pulsed magnetic emission of landslides. For such measurements boreholes must be drilled in the landslide. It is essential that the tubing constituting the borehole’s lining be made of a material which does not attenuate magnetic fields. Besides its primary function, i.e. the registration of landslide magnetic field activity, the system can be used for the structural inhomogeneity of rock strata examination subjected to considerable stresses. The results of examinations of active and inactive landslide in Poland are presented. The post-extraction cave in the SMZ Jelsava Mine in Jelsava, Slovakia, is presented too.
Źródło:
Journal of Telecommunications and Information Technology; 2015, 2; 44-51
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Core loss resistance impact on sensorless speed control of an induction motor using hybrid adaptive sliding mode observer
Autorzy:
Ayana, Tadele
Wogi, Lelissa
Morawiec, Marcin
Powiązania:
https://bibliotekanauki.pl/articles/27309950.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
induction motor
loss minimization
core loss
adaptive observer
sliding mode controller
Opis:
Induction motors (IMs) experience power losses when a portion of the input power is converted to heat instead of driving the load. The combined effect of copper losses, core losses, and mechanical losses results in IM power losses. Unfortunately, the core losses in the motor, which have a considerable impact on its energy efficiency, are not taken into account by the generally employed dynamic model in the majority of the studies. Due to this, the motor rating often corresponds to the worst-case load in applications, but the motor frequently operates below rated conditions. A hybridized model reference adaptive system (MRAS) with sliding mode control (SMC) is used in this study for sensorless speed control of an induction motor with core loss, allowing the motor to operate under a variety of load conditions. As a result, the machine can run at maximum efficiency while carrying its rated load. By adjusting the -axis current in the reference frame in vector-controlled drives, the system’s performance is enhanced by running the motor at its optimum flux. Regarding the torque and speed of both induction motors with and without core loss, the Adaptive Observer Sliding Mode Control (AOSMC) has been constructed and simulated in this case. The AOSMC with core loss produced good performance when the proposed controller was tested.
Źródło:
Archives of Electrical Engineering; 2023, 72, 4; 895--913
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust Flow Controllers for a Single Virtual Circuit in Data Transmission Networks with Lossy Links
Autorzy:
Bartoszewicz, A.
Leśniewski, P.
Powiązania:
https://bibliotekanauki.pl/articles/108780.pdf
Data publikacji:
2012
Wydawca:
Społeczna Akademia Nauk w Łodzi
Tematy:
data transmission networks
congestion control
sliding-mode control
discrete-time systems
Opis:
The paper concerns an application of regulation theory methods to modeling and effective control of connection-oriented data transmission networks. In particular the problem of congestion control in a single virtual circuit of such a network is considered and new discrete-time sliding mode data flow rate controllers are proposed. The controllers are designed in such a way that packet losses are explicitly accounted for. The closed-loop system stability and finitetime error convergence are proved. Moreover, a number of favorable properties of the proposed controllers are stated as theorems, formally proved and verified in a simulation example. It is demonstrated that the proposed controllers guarantee full utilization of the available bandwidth and eliminates the risk of bottleneck node buffer overflow. Application of time-varying sliding hyperplanes helps avoid excessive transmission rates at the beginning of the control process.
Źródło:
Journal of Applied Computer Science Methods; 2012, 4 No. 1; 5-20
1689-9636
Pojawia się w:
Journal of Applied Computer Science Methods
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and Simulation of Direct and Indirect Back EMF Sliding Mode Observer for Sensorless Control of PMSM
Autorzy:
Petro, Viktor
Kyslan, Karol
Powiązania:
https://bibliotekanauki.pl/articles/1193886.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
back-EMF sliding mode observer
sensorless control
PMSM
phase-locked loop
Opis:
This article compares two sensorless control algorithms for a permanent magnet synchronous machine (PMSM) based on the back-EMF sliding mode observer (SMO). Indirect SMO (I-SMO) treats the back-EMF voltages as a disturbance. Direct SMO (D-SMO) considers back-EMF voltages as state-space variables. The same phase-locked loop (PLL) is used for both observers for extraction of the rotor position and speed values from the observed back-EMF voltages. In a sensorless control, the observed speed is used as feedback for the PI controller, and the observed position is used in the Park transformations. Both observers have been implemented and tested with standard field-oriented control. Simulation results indicate rather comparable speed and position estimation precision for both, but the D-SMO indicates slightly higher precision in steady-state. Even more, a tuning procedure of the D-SMO is more straightforward when compared to the I-SMO. Thus, the D-SMO was further verified experimentally with the OP 5600 rapid prototyping device and with a 350 W PMSM drive. Experimental results of the D-SMO are included at the end of the paper.
Źródło:
Power Electronics and Drives; 2020, 5, 40; 215-228
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust continuous third-order finite time sliding mode controllers for exoskeleton robot
Autorzy:
Fellag, Ratiba
Guiatni, Mohamed
Hamerlain, Mustapha
Achour, Noura
Powiązania:
https://bibliotekanauki.pl/articles/1845025.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
exoskeleton robot
higher order
sliding control
homogeneous
robust
trajectory tracking
rehabilitation
Opis:
In this work, continuous third-order sliding mode controllers are presented to control a five degrees-of-freedom (5-DOF) exoskeleton robot. This latter is used in physiotherapy rehabilitation of upper extremities. The aspiration is to assist the movements of patients with severe motor limitations. The control objective is then to design adept controllers to follow desired trajectories smoothly and precisely. Accordingly, it is proposed, in this work, a class of homogeneous algorithms of sliding modes having finite-time convergence properties of the states. They provide continuous control signals and are robust regardless of non-modeled dynamics, uncertainties and external disturbances. A comparative study with a robust finite-time sliding mode controller proposed in literature is performed. Simulations are accomplished to investigate the efficacy of these algorithms and the obtained results are analyzed.
Źródło:
Archive of Mechanical Engineering; 2021, LXVIII, 4; 395-414
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quadrotor UAV control for transportation of cable suspended payload
Autorzy:
Kusznir, Tom
Smoczek, Jarosław
Powiązania:
https://bibliotekanauki.pl/articles/246855.pdf
Data publikacji:
2019
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
transport
UAV
quadrotor
under actuated
cable suspended payload
sliding mode control
Opis:
Payload transportation with UAV’s (Unmanned Aerial Vehicles) has become a topic of interest in research with possibilities for a wide range of applications such as transporting emergency equipment to otherwise inaccessible areas. In general, the problem of transporting cable suspended loads lies in the under actuation, which causes oscillations during horizontal transport of the payload. Excessive oscillations increase both the time required to accurately position the payload and may be detrimental to the objects in the workspace or the payload itself. In this article, we present a method to control a quadrotor with a cable suspended payload. While the quadrotor itself is a nonlinear system, the problem of payload transportation with a quadrotor adds additional complexities due to both input coupling and additional under actuation of the system. For simplicity, we fix the quadrotor to a planar motion, giving it a total of 4 degrees of freedom. The quadrotor with the cable suspended payload is modelled using the Euler-Lagrange equations of motion and then partitioned into translation and attitude dynamics. The design methodology is based on simplifying the system by using a variable transformation to decouple the inputs, after which sliding mode control is used for the translational and pendulum dynamics while a feedback linearizing controller is used for the rotational dynamics of the quadrotor. The sliding mode parameters are chosen so stability is guaranteed within a certain region of attraction. Lastly, the results of the numerical simulations created in MATLAB/Simulink are presented to verify the effectiveness of the proposed control strategy.
Źródło:
Journal of KONES; 2019, 26, 2; 77-84
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lqr-Based Nonlinear Tuning Relay Control Design With Fast Convergence
Autorzy:
Yu, X.
Xia, Y.
Ledwich, G.
Oghanna, W.
Powiązania:
https://bibliotekanauki.pl/articles/908299.pdf
Data publikacji:
1999
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
sterowanie rozdzielcze
sterowanie przekaźnikowe
switching control
LQR
relay control
sliding mode
Opis:
In this article, we present a relay control scheme based on LQR design with fast convergence. This scheme provides a practical and simple way to achieve fast convergence based on the well-known LQR design principle. The controller is a global stabiliser in the sense that for any given initial condition, we can always initialize the controller to drive the system to reach the origin. This controller is tunable in accordance with the position of the system state: the closer to the origin, the larger the control gains, which results in a fast control that maintains bounded control magnitude. It has also been shown that setting matrix Q can significantly influence the tendency of eigenvalues to switch the hyperplane. The relation between matrix Q and the tendency of those eigenvalues has been identified. Simulation results are presented to demonstrate the effectiveness of the scheme.
Źródło:
International Journal of Applied Mathematics and Computer Science; 1999, 9, 2; 313-326
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rocking of freestanding objects: theoretical and experimental comparisons
Autorzy:
Gesualdo, A.
Iannuzzo, A.
Minutolo, V.
Monaco, M.
Powiązania:
https://bibliotekanauki.pl/articles/949322.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
rocking and sliding motion
freestanding rigid body
nonlinear dynamics
experimental testing
Opis:
The methodical study of safeguard of artistic heritage and other devices subjected to earthquake and, in general, to time-dependent forces has considerably spreaded in the last years, thus increasing researchers’ interest in problems concerning motions of rigid objects simply supported on a base plane. The behaviour of piece of equipments, statues, storage tanks, or even tall buildings has been in fact studied as that of rigid bodies with relation to different base excitations. In some cases, the possibility of influencing the quality of motion can be a strong tool to reduce vulnerability, like in the cases in which rocking motion is to be avoided and sliding motion is welcome. This paper focuses the attention on this last problem. This is the same large class of both non-structural and structural elements that can lose their functionality because of earthquake motions. The results of numerical modelling of sliding and rocking motion in presence of both different excitations and mechanical parameters are presented and compared with experimental data performed by the authors. The results developed are in good agreement with the laboratory tests, and this assures the reliability of both the analytical procedure and the determination of the parameters involved.
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 4; 977-991
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dead-beat and reaching-law-based sliding-mode control of perishable inventory systems
Autorzy:
Ignaciuk, P.
Bartoszewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/202382.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sliding-mode control
inventory control
perishable inventories
discrete-time control systems
Opis:
In this paper we consider the problem of efficient control of inventory systems with perishable goods. In the analyzed setting the deteriorating stock at a distribution center used to fulfill unknown, time-varying demand is replenished with delay from a supply source. The challenging issue is to achieve the high service level with minimum costs when the replenishment orders are procured with lead-time delay spanning multiple review periods. On the contrary to the typical heuristic approaches, we apply formal methodology based on discrete-time sliding-mode (SM) control. The proposed SM controller with the sliding plane selected for a dead-beat scheme ensures that the maximum service level is obtained in the system with arbitrary delay and any bounded demand pattern. In order to account for the supplier capacity limitations in the systems with input constraints, we also develop an alternative control strategy based on reaching law. Both controllers achieve a given service level with smaller holding costs and reduced order-to-demand variance ratio as compared to the classical order-up-to policy.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2011, 59, 1; 39-49
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Możliwości odzwierciedlenia warunków eksploatacyjnych i ich efektów w wybranym skojarzeniu toczno-ślizgowym
The possibilities to reflect the operational conditions and their effects in the selected rolling-sliding contact
Autorzy:
Bąkowski, H.
Powiązania:
https://bibliotekanauki.pl/articles/197531.pdf
Data publikacji:
2013
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
właściwości tribologiczne
trwałość
skojarzenie toczno-ślizgowe
tribological properties
durability
rolling-sliding
Opis:
W artykule przedstawiono wpływ najważniejszych czynników eksploatacyjnych, tj. obciążenia, poślizgu i prędkości, na właściwości tribologiczne, tj. zużycie i współczynnik tarcia, które są główną przyczyną zużycia zmęczeniowo-kontaktowego w badanym skojarzeniu toczno-ślizgowym. Otrzymanie zbieżnych efektów na stanowisku laboratoryjnym w odniesieniu do obiektu rzeczywistego umożliwiło sformułowanie końcowych wniosków niezwykle istotnych dla poprawy bezpieczeństwa w ruchu kolejowym oraz wydłużenia trwałości.
The influence of the most important operational factors, ie load, slip and speed on the tribological properties, such as wear, friction coefficient, which is the main cause of wear fatigue in the rolling-sliding. Obtain convergent results as a laboratory for real object has enabled the formulation of final conclusions very important for improving rail safety and extend durability.
Źródło:
Zeszyty Naukowe. Transport / Politechnika Śląska; 2013, 81; 7-10
0209-3324
2450-1549
Pojawia się w:
Zeszyty Naukowe. Transport / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new 4-D hyperchaotic system with no equilibrium, its multistability, offset boosting and circuit simulation
Autorzy:
Vaidyanathan, Sundarapandian
Moroz, Irene M.
Sambas, Aceng
Powiązania:
https://bibliotekanauki.pl/articles/229944.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
chaos
chaotic systems
hidden attractors
sliding mode control
circuit design
synchronization
Opis:
A new 4-D dynamical system with hyperchaos is reported in this work. It is shown that the proposed nonlinear dynamical system with hyperchaos has no equilibrium point. Hence, the new dynamical system exhibits hidden hyperchaotic attractor. An in-depth dynamic analysis of the new hyperchaotic system is carried out with bifurcation transition diagrams, multistability analysis, period-doubling bubbles and offset boosting analysis. Using Integral Sliding Mode Control (ISMC), global hyperchaos synchronization results of the new hyperchaotic system are described in detail. Furthermore, an electronic circuit realization of the new hyperchaotic system has been simulated in MultiSim software version 13.0 and the results of which are in good agreement with the numerical simulations using MATLAB.
Źródło:
Archives of Control Sciences; 2020, 30, 3; 575-597
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ grubości warstwy DLC na właściwości tribologiczne w tarciu ślizgowym
The effect of the DLC layer thickness on the tribological properties in sliding friction
Autorzy:
Piątkowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/189230.pdf
Data publikacji:
2012
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
warstwy DLC
tarcie ślizgowe
zużycie
FIB
DLC layers
sliding friction
wear
Opis:
W pracy przedstawione są wyniki badań tribologicznych wykonanych na próbkach z warstwami o grubości 50 nm, 500 nm i 1300 nm nałożonymi na podłoże ze stali narzędziowej 316L. Warstwy nakładane były metodą RF PACVD. Testy tribologiczne realizowano w węźle tarcia typu kula–powierzchnia płaska z postępowo-zwrotnym ruchem ślizgowym kulki. Grubsze warstwy DLC wykazały stabilny i niski współczynnik tarcia. Ślady tarcia analizowano za pomocą elektronowego mikroskopu skaningowego oraz mikroskopu interferencyjnego. Najmniejsze zużycie zaobserwowano dla próbki z warstwą DLC o grubości 500 nm. Nawet w przypadku intensywnego uszkodzenia, warstwy DLC pełniły funkcję zabezpieczającą i zmniejszały zakres i zmieniały rodzaj zniszczeń.
This paper presents the results of tribological tests made on the samples with a layer thickness of 50 nm, 500 nm and 1300 nm deposited on the surface of 316L tool steel. The DLC layers were made by the RF PACVD method. Tribological tests were carried out on the ball-flat surface friction node, with the reciprocating sliding movement of the ball. The thicker DLC layers showed a stable and low friction coefficient. Friction traces were analysed by scanning electron microscopy and interference microscopy. The lowest wear was observed for the DLC layer with thickness of 500 nm. Even in the case of heavy damage, the DLC layer acted as a protection and reduced the extend and changed the type of damage.
Źródło:
Tribologia; 2012, 3; 137-144
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sterowanie ślizgowe mikrosamolotem w oparciu o wyznaczone momenty sił aerodynamicznych
Sliding mode control of the MAV with used eralier calculated aerodynamical forces and moments
Autorzy:
Koszewnik, A.
Powiązania:
https://bibliotekanauki.pl/articles/387455.pdf
Data publikacji:
2010
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
sterowanie
aerodynamika
mikrosamolot
regulator ślizgowy
control
aerodynamics
microplane model
sliding controller
Opis:
Typowe sterowanie mikrosamolotem odbywa się w klasyczny sposób z wykorzystaniem powierzchni nośnych płatowca. Czasami ze względu na ograniczone możliwości konstrukcyjne MAV i postawione jemu wymagania należy zmienić sposób sterowania MAV a tym samym zmienić sposób powstawania wirów krawędziowych na krawędzi natarcia samolotu. W poniższym artykule w pierwszym etapie zostanie rozpatrzony model MAV z wysuwaną barierą mechaniczną na krawędzi natarcia. W drugim zaś zostanie zaprojektowane prawo sterowania barierą w oparciu o regulator ślizgowy ( ang. sliding controller). Uzyskane w ten sposób badania symulacyjne zostaną ze sobą porównane w celu wyciągnięcia istotnych wniosków.
Nowadays control of MAV progressed in typical way by surface lift vehicle. Sometimes in relative limited possibility structural we may changed way control of MAV. Simultaneously we have changed way appear leading edge vortexes on vehicle. The paper was divided on two stage. In the first step was consider mathematical model of MAV with movable bar mechanical on leading edge. In second step was designed control law for control movable mechanical bar based on sliding controller. Obtained results in simulation was collected and compared.
Źródło:
Acta Mechanica et Automatica; 2010, 4, 3; 70-75
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sliding mode speed control for multi-motors system
Autorzy:
Bouchiba, B.
Hazzab, A.
Glaoui, H.
Med-Karim, F.
Bousserhane, I. K.
Powiązania:
https://bibliotekanauki.pl/articles/384373.pdf
Data publikacji:
2010
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
Multi-Motors systems
sliding mode control
proportional-integral (P1) control
Opis:
Continuous processes in the plastics, textile paper and other industries, require several drives working in synchronism. The aim of this paper is to control speed of the multi motors system, and to maintain a constant mechanical tension between the rollers of the system. Several controllers are considerer, including Proportional-Integral (PI) and sliding-mode control (SMC). Since the PI control method can be applied easily and is widely known, it has an important place in control applications. But this method is insensitive to parameter changes. The advantage of an SMC is its robustness and ability to handle the non-linear behaviour of the system, and is indicated in comparison with traditional proportional-integral (P1) control scheme. Theoretical analysis and simulation results are provided to evaluate the consistency and performances of this control technique (SMC).
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2010, 4, 3; 50-54
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lubrication impact on the value of friction coefficient of coffee beans sliding ever the steel surfaces of various roughness
Autorzy:
Kuzminskyi, R.
Sokolovskyi, O.
Lozovyi, R.
Sheremeta, R.
Zholobko, V.
Powiązania:
https://bibliotekanauki.pl/articles/411159.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
coffee beans
steel surfaces
roughness
dry friction
sliding friction coefficient
lubrication
Opis:
The article analyzes the influence of steel surfaces processing quality on the value of sliding friction coefficient of Robusta and Arabica coffee beans at dry and lubricated fricbica. The research obtained coffee dry and lubrication functions and parameters of sliding friction coefficients distributions and mathematical models for determining the index which depends on the roughness of steel surfaces.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2014, 3, 4; 91-95
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adaptive sliding mode control for ship autopilot with speed keeping
Autorzy:
Liu, Z.
Powiązania:
https://bibliotekanauki.pl/articles/259349.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
surface vessel
speed loss
adaptive control
course keeping
sliding mode control
Opis:
The paper addresses an important issue in surface vessel motion control practice that the ship dynamics and sailing performance can be affected by speed loss. The vessel speed is significantly decreased by the added resistance generated by waves. An adaptive sliding mode course keeping control design is proposed which takes into account uncertain ship dynamics caused by forward speed variations, while avoiding performance compromises under changing operating and environmental conditions. The sliding mode control provides robust performance for time-varying wave disturbances and time-varying changes in ship parameters and actuator dynamics. After combining the unknown but bounded system uncertainties, the design of the adaptation law is obtained which is based on the Lyapunov’s direct method. Simulations on a ship with two rudders illustrate the effectiveness of the proposed solution.
Źródło:
Polish Maritime Research; 2018, 4; 21-29
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Propeller hydrodynamic characteristics in oblique flow by unsteady ranse solver
Autorzy:
Nouroozi, Hossein
Zeraatgar, Hamid
Powiązania:
https://bibliotekanauki.pl/articles/259792.pdf
Data publikacji:
2020
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
DTMB-P4119 propeller
URANS equation
oblique flow
sliding mesh technique
Opis:
Propellers may encounter oblique flow during operation in off-design conditions. Study of this issue is important from the design and ship performance points of view. On the other hand, a propeller operating in oblique flow may sometimes result in a better propulsion efficiency. The main goal of the present study is to provide an insight on the propeller characteristics in the oblique flow condition. In this research, the performance of the DTMB 4419 propeller is studied by the numerical method based on solving Reynolds Averaged Navier‒Stokes (RANS) equations in several inflow angles. The sliding mesh approach is used to model the rotary motion of the propeller. Initially, the numerical method is verified by grid and time step dependency analysis at various inflow angles. Additionally, computed results at zero inflow angle are compared with the available experimental data and good agreement is achieved. Finally, the forces and moments acting on the propeller are obtained for 0° to 30° inflow angles. It is concluded that the inflow angle up to 10° has no significant influence on the thrust and torque coefficients as well as the propeller efficiency. However, at high angles up to 30°, the thrust and torque coefficients increase as the inflow angle increases, which may result in a significant improvement of propeller efficiency.
Źródło:
Polish Maritime Research; 2020, 1; 6-17
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomechanical analysis of Yangs spear turning-stab technique in Chinese martial arts
Autorzy:
Liu, Yufeng
Kong, Jianguo
Wang, Xiuping
Shan, Gongbing
Powiązania:
https://bibliotekanauki.pl/articles/1922261.pdf
Data publikacji:
2020-08-05
Wydawca:
PPHU Projack Jacek Wąsik
Tematy:
3D motion capture
force measurement
phases
hiding
sliding
relative motion
Opis:
The Yang's spear turning-stab was a legendary technique, applied in ancient battles in China. It resulted in numerous famous winnings. The mythical aspect of the technique is a victory in fleeing and back-facing a fighter. Now the skill is a spear technique of Chinese martial arts that is learned and excised by many Chinese Gungfu practitioners. Due to a dearth of scientific study on the skill, the uniqueness and its winning secretes are still unknown. The aim of this study is to demystify the skill by using a synchronized measurement of 3D motion capture (VICON 12 camera system), stab-force measurement (AMTI force platform). Six Gungfu athletes with more than 30 years training experience participated in the study. Both the Yang's spear turning-stab (used by a fleer) and spear forward-stab (used by a chaser) were measured and biomechanically analyzed. The results reveal that there would be six secrets for its historical successes. They are 1) showing weakness (i.e. pretend to be defeated), 2) shortening the stab for quick turning, 3) hiding the stab for a covert attack, 4) leaving less reaction time for opponent, 5) generating higher stab-force than opponent, and 6) leaning backward for a stable stab-posture. These secrets identify elements necessary for systematic training toward a reliable execution of the skill. This skill shows the delicate characteristics of Chinese martial culture. Learning and training the skill would benefit trainees both physically and culturally.
Źródło:
Physical Activity Review; 2020, 2, 8; 16-22
2300-5076
Pojawia się w:
Physical Activity Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of the dynamics of forced motion on the static friction in metal-polymer sliding pairs
Wpływ dynamiki wymuszenia ruchu na opory tarcia statycznego w parach ślizgowych metal–polimer
Autorzy:
Opałka, Mariusz
Wieleba, Wojciech
Radzińska, Angelika
Powiązania:
https://bibliotekanauki.pl/articles/2055631.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
dynamics of start
sliding polymers
friction
dynamika ruchu
polimery ślizgowe
tarcie
Opis:
The resistance during the frictional interaction of polymeric materials with metallic materials is characterized by a significant dependence on the dynamics of the motion inputs. In a metal-polymer friction pair, the static friction resistance during standstill under load depends on the rate of growth of the force causing the relative motion. Tribological tests of selected (polymer-metal) sliding pairs were carried out. The selected polymers were polyurethane (TPU), polysulfone (PSU), and silicone rubber (SI). They interacted with a pin made of normalized C45 steel under unitary pressure p = 0.5 MPa in dry friction conditions at different gradients of the force driving the relative motion (dF/dt = 0.1-20 [N/s]). The static friction coefficient of the selected sliding pairs was determined on the basis of the recorded static friction force values. The test results show a significant influence of the rate of increase in the motion driving force on the values of static friction resistance. This is mainly due to the viscoelastic properties of polymers.
Opory podczas współpracy ciernej materiałów polimerowych z materiałami metalicznymi cechują się znaczną zależnością od dynamiki wymuszeń ruchu. Podczas postoju pod obciążeniem pary trącej metal–polimer, opory tarcia statycznego są zależne od prędkości narastania siły wywołującej ruch względny. Przeprowadzono badania tribologiczne wybranych par ślizgowych (polimer–metal). Polimerami wybranymi do badań były: poliuretan (TPU), polisulfon (PSU) oraz guma silikonowa (SI). Współpracowały one trzpieniem wykonanym ze stali C45 w stanie normalizowanym dla nacisku jednostkowego p = 0,5 MPa w warunkach tarcia suchego dla różnych gradientów przyrostu siły wymuszającej ruch względny dF/dt = 0,1 – 20 N/s. Na podstawie rejestrowanych wartości siły tarcia statycznego wyznaczony został współczynnik tarcia statycznego wybranych par ślizgowych. Wyniki badań ukazują znaczący wpływ prędkości narastania siły wymuszającej ruch na wartości oporów tarcia statycznego. Głównym powodem takiego stanu rzeczy są lepko-sprężyste własności polimerów.
Źródło:
Tribologia; 2021, 295, 1; 21--26
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of Tribological Parameters of Pre-Positioned Wire Based Electron Beam Additive Manufactured Ti-6Al-4V Alloy
Autorzy:
Manjunath, Anandan
Anandakrishnan, V.
Ramachandra, S.
Parthiban, Kannan
Sathish, S.
Powiązania:
https://bibliotekanauki.pl/articles/2106567.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
additive manufacturing
dry sliding wear
titanium alloy
wear analysis
wear mechanisms
Opis:
The versatile application of titanium alloy in the aerospace industry and it’s hard to machine characteristics focus towards the additive manufacturing. The Ti-6Al-4V alloy is manufactured using the electron beam source with a novel method of prepositioned titanium alloy wires. The tribology of the additive manufactured titanium alloy under dry sliding condition is experimented and analysed using Taguchi technique. The targeted objective of minimum tribological responses are attained with the identified optimal parameters as load - 9.81 N, sliding velocity - 3 m/s, sliding distance - 3000 m for minimum specific wear rate and load - 9.81 N, sliding velocity - 3 m/s, sliding distance - 1000 m for minimum coefficient of friction. Among the parameters tested, load is found to be the dominant factor on the tribology of additively manufactured titanium alloy. The morphological analysis on the worn surface and debris revealed the existence of abrasion, delamination and adhesion wear mechanisms. The increase in the load dominantly showed the appearance of delamination mechanism.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 2; 447--454
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sliding Wear Behaviour and Corosion Resistance to Ringer’s Solution of Uncoated and DLC Coated X46Cr13 Steel
Autorzy:
Scendo, M.
Radek, N.
Konstanty, J.
Staszewska, K.
Powiązania:
https://bibliotekanauki.pl/articles/355518.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
diamond-like carbon
sliding wear properties
corrosion in Ringer’s solution
Opis:
Sliding wear properties and corrosion resistance in Ringer’s solution of uncoated and diamond-like carbon (DLC) coated X46Cr13 steel was tested. The Raman spectra showed that the DLC film was successfully coated by plasma assisted CVD method onto the steel surface. The wear test, carried out using a ball-on disk tribometer, revealed that the DLC coating show better resistance to sliding wear and lower friction coefficient against a 100Cr6 steel ball than five times softer X46Cr13 steel. The oxidation kinetic parameters were determined by means of both the gravimetric and electrochemical method. It was found that the DLC coating markedly decreased the rate of corrosion of the X46Cr13 steel, irrespective of the corrosion mechanism involved.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 4; 1895-1900
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new multistable double-scroll 4-D hyperchaotic system with no equilibrium point, its bifurcation analysis, synchronization and circuit design
Autorzy:
Vaidyanathan, Sundarapandian
He, Shaobo
Simbas, Aceng
Powiązania:
https://bibliotekanauki.pl/articles/1409110.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hyperchaos
hyperchaotic systems
hidden attractors
multistability
sliding mode control
circuit design
Opis:
In this work, we have developed a new 4-D dynamical system with hyperchaos and hidden attractor. First, by introducing a feedback input control into the 3-D Ma chaos system (2004), we obtain a new 4-D hyperchaos system with no equilibrium point. Thus, we derive a new hyperchaos system with hidden attractor. We carry out an extensive bifurcation analysis of the new hyperchaos model with respect to the three parameters. We also carry out probability density distribution analysis of the new hyperchaotic system. Interestingly, the new nonlinear hyperchaos system exhibits multistability with coexisting attractors. Next, we discuss global hyperchaos self-synchronization for the new hyperchaos system via Integral Sliding Mode Control (ISMC). As an engineering application, we realize the new 4-D hyperchaos system with an electronic circuit via MultiSim. The outputs of the MultiSim hyperchaos circuit show good match with the numerical MATLAB plots of the hyperchaos model. We also analyze the power spectral density (PSD) of the hyperchaos of the state variables using MultiSim.
Źródło:
Archives of Control Sciences; 2021, 31, 1; 99-128
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved direct torque control of induction motors using adaptive observer and sliding mode control
Autorzy:
Kouchih, D
Tadjine, M.
Boucherit, M. S.
Powiązania:
https://bibliotekanauki.pl/articles/229910.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
adaptive observer
direct torque control
induction motor
sensorless
sliding mode control
Opis:
This paper presents the synthesis of an adaptive observer which is used for the improvement of the direct torque control of induction motor drives. The observer detects stator flux components in two-phase stationary reference frame, rotor speed and stator resistance by measure of the stator terminal voltages and currents. The observer is adapted using a simple algorithm which does not imply a high computational load. Stability analysis based on Lyapunov theory is performed in order to guarantee the closed loop stability. Simulation tests under load disturbance and stator resistance variation are provided to evaluate the consistency and performance of the proposed control technique in the low and high speeds.
Źródło:
Archives of Control Sciences; 2013, 23, 3; 361-376
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania własności ruchowych zdegenerowanych stawów synowialnych
Tribological properties of degenerate synovial joints
Autorzy:
Koziarski, C.
Trzaskacz, T.
Ferenc, Z.
Powiązania:
https://bibliotekanauki.pl/articles/971540.pdf
Data publikacji:
2012
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
biotribologia
tarcie toczno-ślizgowe
chrząstka stawowa
biotribology
rolling-sliding friction
articular cartilage
Opis:
W ludzkim organizmie chrząstka stawowa jest jednym z tych elementów, które są najbardziej narażone na zmiany przeciążeniowo-zwyrodnieniowe. W pracy przedstawiono wyniki badań, które mają na celu określenie własności tribologicznych zdegenerowanych chrząstek stawowych człowieka, a co się z tym wiąże stopnia zużycia biologicznego węzła ciernego. Badania przeprowadzono na drodze doświadczalnej, z wykorzystaniem modeli fizycznych. W badaniach próbka i przeciwpróbka wykonują ruch ślizgowo-toczny, co odpowiada możliwie wiernie ruchowi wzajemnemu powierzchni ciernych w stawie. Pomiary momentu tarcia realizowano dla ruchu wahadłowego, przy zachowaniu warunków płynnego tarcia toczno-ślizgowego. Badania realizowano przy sile nacisku Fn = 0÷105[N] i prędkości poślizgu vs = {0, 3, 6, 9}[mm/s] przy prędkości obrotowej w punkcie pomiarowym ω = 0,33[s-1] Materiał badawczy klasyfikowano pod względem uszkodzeń powierzchni chrząstki stawowej. Pozwoliło to na porównanie kolejnych stadiów degeneracji chrząstki i odniesienie ich do zmian parametrów tribologicznych w postaci momentu tarcia i współczynnika tarcia na badanych powierzchniach.
Joint cartilage in the human body is one of those elements that is most vulnerable to overload and degenerative changes. These changes are influenced by factors such as traffic accidents, lack of physical activates or metabolic disturbances. In this paper, the results of research aimed at the determination of the degeneration rate of the cartilage of a human joint on its tribological properties are presented. This experimental research was carried out using physical models. To carry out this research, a test stand modelling a fundamental scheme of loading and motion for the knee joint had been constructed. The measurements of the friction moment were realised for the fluctuate motion, with the proceeding of the time of rolling- sliding fluid friction. The research was realised for load force Fn = 0÷105[N]. (Sliding velocity vs = {0, 3, 6, 9}[mm/s], and the speed of rotation in measuring point ω = 0.33[s-1]) The specimen and counter specimen used in the testing are in sliding/rolling contact, which reflects, to a maximum degree possible, the relative motion of frictional surfaces in a joint. The results of this research were used for the evaluation of the influence of degenerative changes on tribological changes in the joint cartilage.
Źródło:
Tribologia; 2012, 5; 55-63
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polymer Blended (Epoxy/Vinylester) Nanocomposites Resistance against Pulling & Sliding Wear Loads
Autorzy:
Harisankar, P.
Reddy, Y. V. M.
Reddy, K. H.
Powiązania:
https://bibliotekanauki.pl/articles/971334.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
blended polymer composite
vinylester
epoxy
mechanical properties
sliding wear
Taguchi Method
SEM
Opis:
This paper discloses the development and synthesis of polymer blended nanocomposites filled with nanoclay. The hybridization of epoxy is mixed with vinylester resin (VER) to prepare polymer blend filled with organoclay was studied to enhance mechanical properties of epoxy/VER. Clay loading was done in such a way that with different wt. proportions viz.1, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0, & 7.5 w % ratios. Appropriately cured samples gave excellent mechanical and tribological properties. Results showed that the tensile strength of the composites increased with increase in filler content for the range of filler contents (2.5-4 % vol.). The results indicated that at 4 % wt. of filler concentration the tensile strength obtained is good i.e. 47.79 MPa with density 1.37 gm/cm3 and hardness 45.5. Dry Sliding wear tests were also conducted by following a well-planned experimental schedule based on Taguchi’s design of experiments, considering parameters like Filler content, Normal load, Sliding Velocity and Sliding distance, on a Pin-On-Disc set-up (ASTM G-99 standard, Make: DUCOM Engineers, Bangalore, India). In the experimentation composite pins were worn against a rotating steel disc (Europe Norm) EN-31, (Rockwell C Hardness) HRC 60 and (Roughness Average) Ra 0.02 microns. Control factors like Filler Content, Normal Load were found to be significant factors affecting the Wear rate i.e. the inclusion of nanoclay as filler found to be contributed in improving the wear resistance of the composite. SEM observations are made to probe the wear mechanisms involved.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 18; 75-90
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental research on insufficient water lubrication of marine stern tube journal bearing with elastic polymer bush
Autorzy:
Barszczewska, Agnieszka
Powiązania:
https://bibliotekanauki.pl/articles/1573813.pdf
Data publikacji:
2020
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
lubrication failure
bearing seizure
water-lubricated bearing
non-metallic bearing
sliding bearing
Opis:
Water-lubricated bearings with polymer bushes are steadily gaining popularity due to their advantages, including environmental friendliness, relatively simple construction and long-term operation. Nevertheless, in practice instances of damage to such bearings occur due to insufficient or absent flow of the lubricating agent. In this study, experimental tests established that elastic polymer bush bearing is capable of operating without excessive wear for a period of at least 60 minutes under conditions of marginal water flow and typical loads for stern tube journal bearings of small ships.
Źródło:
Polish Maritime Research; 2020, 4; 91-102
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wybrane czynniki wpływające na odporność na zużycie węzłów ślizgowych
Selected factors effecting on wear resistance of sliding pairs
Autorzy:
Gałda, L.
Powiązania:
https://bibliotekanauki.pl/articles/317037.pdf
Data publikacji:
2016
Wydawca:
Instytut Naukowo-Wydawniczy "SPATIUM"
Tematy:
badania tribologiczne
węzły ślizgowe
wpływ czynników
tribological tests
sliding knots
impact factors
Opis:
W artykule omówiono wpływ wybranych czynników charakteryzujących elementy węzłów ślizgowych oraz wybranych warunków eksploatacji na odporność na zużycie smarowanych węzłów tarcia. Przedstawiono wyniki badań tribologicznych realizowanych przy zróżnicowanej chropowatości powierzchni stalowej tarczy, wyrażonej parametrem Ra w zakresie 0,05-0,24 μm. Badaniom poddano również węzły cierne o zróżnicowanej twardości stalowego elementu w zakresie 22-42HRC. Badania odporności zrealizowano w odniesieniu do dwóch różnych skojarzeń materiałowych: stal-stal (42CrMo4 - 100Cr6) oraz stal-ceramika (42CrMo4 - SiC) w celu oceny możliwości zastosowania ceramiki w węzłach ciernych. W wyniku zrealizowanych badań przy różnych obciążeniach wykazano, że chropowatość powierzchni, twardość i rodzaj materiału, a także warunki eksploatacji wywierają istotny wpływ na odporność na zużycie współpracujących ślizgowo części maszyn.
The effect of selected factors characterizing the elements of sliding pairs and the influence of selected exploitational conditions on wear resistance are described in the article. The results of tribological tests realized at different surface roughness of steel discs, Ra in the range of 0,05 – 0,24 μm, are presented. The influence of material hardness of the steel discs in the range of 22-42HRC was also tested. The experiments were realized with the usage of two material sets: steel-steel (42CrMo4 - 100Cr6) and steel-ceramic (42CrMo4 - SiC) to assess the possibility of ceramic application on the sliding assemblies construction. As the result of the experiments it was demonstrated that the surface roughness, material hardness, material type and also the exploitational conditions influenced significantly on the wear of sliding elements of machines.
Źródło:
Autobusy : technika, eksploatacja, systemy transportowe; 2016, 17, 6; 861-865
1509-5878
2450-7725
Pojawia się w:
Autobusy : technika, eksploatacja, systemy transportowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of the distribution of variable characteristics determining the asymmetry of the sealing rings sliding surfaces on the values of friction loss coefficients and other selected parameters of oil film
Autorzy:
Wróblewski, P.
Powiązania:
https://bibliotekanauki.pl/articles/133559.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
rings asymmetrical sliding surface
friction loss
oil film
straty tarcia
film olejowy
Opis:
The article presents the results of research on the effect of the change in coordinates that determine the location of the common vertex of the parabolas and ellipses demonstrating the asymmetric shape of the rings sliding surfaces on the change in the thickness of oil film, the amount of scraped oil, and the oil left on the cylinder wall, once a set of selected sealing rings has passed, as well as the results concerning friction losses. Mathematical relationships of the asymmetric shapes of the rings sliding surfaces were presented, and the values of coefficients characterizing selected parameters of oil film and friction losses were determined. It was confirmed that there is a large dependence of the coordinate values of the vertices determining the asymmetric shapes of these surfaces on the condition and cooperation between piston rings and the cylinder bearing surface, and mainly on the amount of the oil scraped in the selected engine strokes.
Źródło:
Combustion Engines; 2017, 56, 4; 107-116
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computer image analysis of sliding couple elements upper layers
Komputerowa analiza obrazu warstw wierzchnich elementów skojarzeń ślizgowych
Autorzy:
Golba, P.
Skoneczny, W.
Powiązania:
https://bibliotekanauki.pl/articles/209917.pdf
Data publikacji:
2007
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
analiza obrazu
skojarzenia ślizgowe
warstwy wierzchnie
image analysis
sliding coupe
upper layers
Opis:
The results of a computer image analysis of sliding couple elements’ upper layers are presented in the paper. When performing the measurements, the primary focus was placed on fibres’ diameters and porosity analysis. One of the objectives of the measurements made was to determine the usefulness of a computer image analysis for the examination of functional properties of future upper layers. Algorithms were proposed to transform the images of sliding couple elements’ upper layers, allowing complete or partial automation of the measurements.
W pracy przedstawiono wyniki komputerowej analizy obrazu warstw wierzchnich elementów skojarzeń ślizgowych. Wykonując pomiary skupiono się na pomiarach średnicy włókien oraz analizie porowatości. Jednym z celów przeprowadzenia pomiarów było określenie przydatności komputerowej analizy obrazu podczas badania właściwości użytkowych przyszłych warstw wierzchnich. Zaproponowano algorytmy przekształceń obrazu warstw wierzchnich elementów skojarzeń ślizgowych pozwalające na całkowite lub częściowe zautomatyzowanie pomiarów.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2007, 56, sp.1; 43-52
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sliding mode tracking control for unmanned helicopter using extended disturbance observer
Autorzy:
Ullah, Ihsan
Pei, Hai-Long
Powiązania:
https://bibliotekanauki.pl/articles/229728.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
unmanned helicopter
external disturbances
sliding mode control
extended disturbance observer
mismatched uncertainty
Opis:
This paper presents a robust control technique for small-scale unmanned helicopters to track predefined trajectories (velocities and heading) in the presence of bounded external disturbances. The controller design is based on the linearized state-space model of the helicopter. The multivariable dynamics of the helicopter is divided into two subsystems, longitudinallateral and heading-heave dynamics respectively. There is no strong coupling between these two subsystems and independent controllers are designed for each subsystem. The external disturbances and model mismatch in the longitudinal-lateral subsystem are present in all (matched and mismatched) channels. This model mismatch and external disturbances are estimated as lumped disturbances using extended disturbance observer and an extended disturbance observer based sliding mode controller is designed for it to counter the effect of these disturbances. In the case of heading-heave subsystem, external disturbances and model mismatch only occur in matched channels so a second order sliding mode controller is designed for it as it is insensitive to matched uncertainties. The control performance is successfully tested in Simulink.
Źródło:
Archives of Control Sciences; 2019, 29, 1; 169-199
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of Wear Resistance of Functional Composite Polymeric Materials and Durability of Metal-Polymer Bearings
Autorzy:
Chernets, Myron
Świć, Antoni
Kornienko, Anatolii
Yurchuk, Alina
Powiązania:
https://bibliotekanauki.pl/articles/2201913.pdf
Data publikacji:
2023
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
polyamides
wear resistance
composites
dry sliding friction
metal-polymer plain bearings
durability
Opis:
A method of tribological testing of models with such sliding friction using a simple pin-on-disc mechanism was presented. Wear resistance indicators of unfilled polyamides PA6, PA66 and composites based on polyamide PA6+30GF, PA6+30CF, PA6+MoS2, PA6 and oil coupled with steel C45 are determined. They, as polymeric materials with the property of self-lubrication, they are often used in metal-polymer dry friction bearings. Based on them, wear resistance characteristics of these polymeric materials at sliding friction are established. They are used as basic parameters for developed by authors mathematical model of material wear kinetics at sliding friction and analytical research method of metal-polymer sliding bearings research. For comparative assessment of wear resistance of the investigated polymeric materials, their wear resistance diagrams are constructed. Thef show the functional dependence of wear resistance on specific friction forces. It is proved that the wear resistance of materials nonlinearly depends on specific pressure, i.e., the specific friction forces. Qualitative and quantitative influence of the type and structure of fillers (which improve the tribological properties of the base polymer PA6) on their wear resistance has been established. The forecast estimation of durability of metal polymer bearings made of the specified polyamides by the author's method of calculation taking into account their various wear resistance, characteristics of elasticity and conditions of dry friction is carried out. The research results are presented graphically, which facilitates their understanding and analyses.
Źródło:
Advances in Science and Technology. Research Journal; 2023, 17, 2; 258--267
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling the trochoidal gearing with respect to the uniform teeth wear
Modelowanie przekładni trochoidalnej z uwagi na równomierne zużycie zębów
Autorzy:
Ivanović, L.
Josifović, D.
Devedžić, G.
Powiązania:
https://bibliotekanauki.pl/articles/190830.pdf
Data publikacji:
2009
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
przekładnia trochiodalna
poślizg względny
równierne zużycie
trochoidal gearing
specific sliding
uniform wear
Opis:
This paper presents a theoretical model of gearing with a modified trochoidal profile applied to Gerotor pumps. Gerotor pumps belong to the category of rotating machines whose kinematics is based on the principles of a planetary mechanism with internal gearing. Using geometrical and kinematical models of the trochoidal gearing, we provide a detailed analysis of specific sliding at the contact points of the profiles, as well as the relations for its determination. Specific sliding is one of the most significant constraining factors in the selection of the geometrical parameters of the gearing profile, which indicates conditions for appearing friction and wear of the tooth contact surface. The key objective in optimal gerotor pump design is to provide the appropriate selection of geometrical parameters of the gearing, leading to the uniform wear of meshing gears teeth profiles. This requires ensuring the uniform wear of meshing profiles at the point with highest value of sliding velocity, i.e. at the contact points most distant from the pitch point. Consequently, the methodology described in the paper defines the constraints to enable uniform wear of meshing gear teeth profiles from the kinematical point of view.
W referacie przedstawiono model teoretyczny zmodyfikowanego zazębienia trochoidalnego, które jest stosowane w pompach systemu Gerotor. Pompy Gerotor należą do maszyn wirujących, których kinematyka oparta jest na zasadzie mechanizmu planetarnego z zazębieniem wewnętrznym. Za pomocą modeli geometrycznych i kinematycznych przeprowadzono szczegółową analizę poślizgu względnego w punktach styku profili; podano też zależności do jego określenia. Poślizg względny jest jednym z najbardziej istotnych czynników spośród parametrów geometrycznych decydujących o warunkach tarcia i zużyciu kontaktujących się powierzchni. Zasadniczym zadaniem w konstrukcji pomp Gerotor jest właściwy dobór parametrów zazębienia dla uzyskania równomiernego zużycia w punkcie z największą prędkością poślizgu, tj. w punkcie najbardziej oddalonym od bieguna zazębienia. Metodologia przedstawiona w referacie umożliwia określenie warunków dla uzyskania równomiernego zużycia z punktu widzenia kinematyki.
Źródło:
Tribologia; 2009, 1; 63-75
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Właściwości tribolgiczne warstwy wierzchniej z borem w warunkach tarcia ślizgowego
Tribological characteristics of the surface layer with boron under sliding friction onditions
Autorzy:
Lubas, J.
Powiązania:
https://bibliotekanauki.pl/articles/190836.pdf
Data publikacji:
2009
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
tarcie ślizgowe
zużycie
obróbka powierzchniowa
bor
sliding friction
wear
surface treatment
boron
Opis:
Właściwości tribologiczne par ciernych zależą od ich konstrukcji, zastosowanych materiałów i przeprowadzonej obróbki powierzchniowej elementów pary. Celem badań było wyznaczenie wpływu modyfikacji warstwy powierzchniowej elementów stalowych borem w parach pracujących w warunkach tarcia ślizgowego. Badania porównawcze przeprowadzono na testerze T-05 typu rolka–klocek. W celu realizacji programu badań wykonano próbki pierścieniowe z trzech gatunków stali: 38CrAlMo5-10, 46Cr2 i 30MnB4. Próbki te azotowano jonowo, borowano w proszku, borowano laserowo oraz metodą PVD wykonano powłokę TiB2. Próbki pierścieniowe skojarzone zostały w warunkach testu z przeciwpróbkami wykonanymi ze stopu łożyskowego AlSn20, a obszar tarcia smarowano olejem silnikowym Lotos mineralny 15W/40. Przeprowadzone badania wykazały, że warstwy powierzchniowe borowane w proszku wpływają na obniżenie współczynnika tarcia podczas rozruchu, a jego maksymalne wartości są zbliżone do zmierzonych w skojarzeniach z warstwami azotowanymi i ulepszanymi cieplnie ze stali 30MnB4. Największe wartości współczynnika tarcia i najwyższe temperatury w obszarze tarcia występują w parach z próbkami pierścieniowymi z warstwą borowaną laserowo i z powłoką TiB2. Zużycie stopu łożyskowego AlSn20 jest największe w skojarzeniu z przeciwpróbką z powłoką TiB2, a najniższe zużycie zmierzono w skojarzeniach z warstwami azotowanymi i ulepszanymi cieplnie.
The properties of the frictional slide couplings depend on the constructional material used and technology applied during the production process. The tribological properties of the frictional coupling are the resultant of the coupling construction and properties of the cooperating surfaces. The surface layer may be shaped by technological processes through the correct material selection used for these elements and technology applied for the surface treatment. Currently, numerous methods are used in producing the surface layers, which protect against tribological wear; however, particularly advantageous properties feature those coatings with boron. These coatings feature a high degree of the hardness of the structures, resistance to wear and corrosion, and good fatigue properties, depending on the technological preparation of the base. The purpose of the study to determine the influence of the boron modification of the technological surface layer on the characterisation of the operation of frictional pairs under the conditions of mixed friction, and in practical application, increasing of the durability and reliability of frictional pairs and, in consequence, whole technical objects, such as automobiles. In order to create surface layers modified with boron, technological processes were selected that allowed for the creation of these layers on the elements of a combustion engine. These processes were used for the treatment of the surface layer of annular samples for stand test on the T-05 block-on-ring wear tester. Three types of steel were used in the creation of annular samples, 38CrAlMo5-10, 46Cr2, and 30MnB4. Samples from 38CrAlMo5-10 steel were nitrided in the atmosphere H2 + N2, at the temperature of 500°C for 6 hours. Samples from 46Cr2 steel were borided in powder, at the temperature of 950°C for 8 hours. In the boronizing process, powder of the following composition was used: B4C-30%, Al2O3-68%, NH4Cl and NaF. Samples from 46Cr2 steel were also laser-borided, with the use of CO2 laser (power of beam P = 2 kW, spot diameter d = 4 mm, energy density 160 W/mm2, tracking speed v = 16 mm/s, gas carrier –argon). The boronizing process consisted in covering the annular sample with the layer of amorphous boron and liquid glass and melting with a laser beam. Also, the samples from steel 46Cr2 were covered with a TiB2 coating, using the PVD method (temperature 400°C, time 40 min, pressure in ionization chamber p = 2,5 x 10-2 bara). The sample of 30MnB4 steel was hardened and tempered, and hardening was at the temperature of 800°C, and drawing temper was at the temperature of 450°C. Modified surface layers of annular samples were matched under test conditions with counter samples made from AlSn20 bearing alloys. Tested slide pairs were lubricated during the stand test with 15W/40 Lotos mineral engine oil. On the basis of the tests and the analysis of the results, it was concluded that the boron-modified surface layers can be applicable in the slide couplings operating under mixed friction conditions, and their tribological properties are the effect of the interaction between the surface layers of the slide coupling elements and the lubricating oil. The modified surface layer in the process of boronizing in powder coupled with the AlSn20 bearing alloy is characterised by low friction resistance and temperature, which ensures that the slide coupling has conducive conditions for start-up and fast stabilisation of the friction conditions. In turn, the laser borided surface layer and layer TiB2 causes intensive friction processes in the slide coupling, which generates high friction resistance and temperature and intensifies the processes of bearing alloy wear. It was stated that the use of 30MnB4 steel in the slide coupling after the hardening and tempering ensures similar work parameters and a comparable level of wear of the bearing alloy, as in the application of 38CrAlMo5-10 steel with a nitrided surface. The research proved that the lubrication of the friction area with the mineral oil has an influence on the decrease of wear of the bearing alloy and the decrease of the matching parameters of the moment of friction and temperature, mainly in the couplings with the AlSn20 alloy counter samples. Using the boron-modification processes of surface layers in slide couplings operating under the conditions of mixed friction, it is possible to decrease the costs of material using mild-alloy steel or carbon steel and to decrease the costs of exploitation by increasing the durability of elements. However, each time surface layers with boron are used on a large scale, it should be preceded by economic calculation.
Źródło:
Tribologia; 2009, 1; 97-112
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An elbow planar manipulator driven by induction motors using sliding mode control for current loop
Autorzy:
Diniz, E. C. de
Júnior, A. B. S.
Honório, D. A.
Barreto, L. H. S. C.
Reis, L. L. N. dos
Powiązania:
https://bibliotekanauki.pl/articles/206213.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
sliding mode control
induction motor drives
manipulators
digital signal processor
PI controllers
Opis:
The control of a planar elbow manipulator driven by a squirrel-cage induction motor using sliding mode control (SMC) is presented in this paper. The modeling of the manipulator mechanical coupling as a load applied to the induction motor shaft is developed. This has direct influence on both dq currents, which are chosen as the sliding manifold instead of controlling both mechanical and electrical parts as individual processes like most industrial manipulators do. Conventional proportional-integral (PI) controllers are used for each loop, implying easy design procedure and implementation with low computational effort. The system can then be implemented by using a digital signal processor (DSP) and applied in industrial environments. Simulation and experimental results on a real manipulator are shown to validate the proposed control scheme. The results show that there is low steady-state error for the manipulator position.
Źródło:
Control and Cybernetics; 2012, 41, 2; 395-413
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fazownik samoczynny z ostrzem napinanym sprężyną śrubową
The self-acting chamfering tool with blade tensioned by helical spring
Autorzy:
Cichosz, P.
Karolczak, P.
Kołodziej, M.
Kowalski, M.
Skowronek, H.
Waszczuk, K.
Powiązania:
https://bibliotekanauki.pl/articles/194703.pdf
Data publikacji:
2017
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
narzędzie skrawające
płoza ślizgowa
krawędź
fazowanie
cutting tool
sliding skid
edge
chamfering
Opis:
Współczesna technologia dąży do maksymalnej efektywności wytwarzania z zachowaniem odpowiedniej dokładności wytwarzanych elementów. Załamywanie krawędzi realizowane standardowymi metodami może być czasochłonne. Fazowanie narzędziami samoczynnymi, dostępnymi na rynku, nie gwarantuje odpowiedniej dokładności wymiarów i właściwości fazek, szczególnie w produkcji seryjnej. W pracy przedstawiono ideę fazowania narzędziem posiadającym ostrze z płozą ślizgową, napinane sprężyną śrubową. Pokazano proces konstrukcji tego narzędzia. Zaprezentowano jego końcową wersję oraz wybrane wyniki fazowania tym narzędziem. Pokazano główne zalety takiego fazownika wraz z jego wadami, a także zasugerowano możliwe dalsze usprawnienia konstrukcji narzędzia, które mogą wady te wyeliminować.
Modern technology strives to maximum productivity while maintaining the correct accuracy of manufactured components. Chamfering of the edges by standard methods increases the production time. Chamfering with self-acting tools available on the market does not guarantee the proper dimensions and properties of the chamfer, especially in mass production. This paper presents the idea of chamfering by the tool with a sliding blade and tensioned with helical spring. The construction processes of this tool have been shown. Its final version and selected chamfering results are presented. The main advantages of such a chamfer with its disadvantages are shown, and further possible improvements to the design of the tool, which can eliminate disadvantages, are suggested.
Źródło:
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika; 2017, z. 89 [295], 4; 479-486
0209-2689
2300-5211
Pojawia się w:
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fazownik samoczynny z ostrzem napinanym sprężyną piórową
The self-acting chamfering tool with blade tensioned by leaf spring
Autorzy:
Cichosz, P.
Kowalski, M.
Karolczak, P.
Kołodziej, M.
Skowronek, H.
Waszczuk, K.
Powiązania:
https://bibliotekanauki.pl/articles/195852.pdf
Data publikacji:
2017
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
narzędzie skrawające
fazowanie
krawędź
element ślizgowy
cutting tool
chamfering
edge
sliding element
Opis:
Problemem, który może generować znaczne koszty oraz zwiększać czasochłonność procesów technologicznych, są czynności związane z fazowaniem i gratowaniem krawędzi obrobionych wcześniej przedmiotów. Problem ten jest szczególnie istotny w przypadku obróbki masowej, kiedy ważne jest utrzymanie wysokiej efektywności wytwarzania. Dotychczas stosowane narzędzia do fazowania krawędzi, których konstrukcja opiera się na sprężyście umocowanych ostrzach, mają tę wadę, że wielkość i regularność wykonywanej fazy są uzależnione od zakłóceń losowych, np. zmiennych właściwości materiału półfabrykatu. Problem ten nasila się w przypadku kształtowania przedmiotów z materiałów plastycznych lub kompozytowych w obecności nieregularnych wypływek i zadziorów. W pracy omówiono proces konstrukcji i finalną wersję narzędzia do fazowania, wykonanego w wariancie z ostrzem ze zintegrowaną płozą ślizgową i napinanego sprężyną piórową. Omówiono wybrane wyniki fazowania tym narzędziem.
One of the problems that generate significant costs and increase the time consuming process of the process is the chamfering and deburring the edges of previously machined objects. In the case of mass processing it is particularly important to maintain high efficiency of production. The size and regularity of the made phase subjected to random disturbances such as the variable properties of the material of the semi-finished product are indicated as disadvantages of existing tools for chamfering the edges which design is based on the elastically mounted blades. This problem arises when objects made from plastic or composite materials are machined in the presence of irregular spikes and burrs. This article discusses the construction process and presents the final version of the chamfering tool with a blade with integrated sliding skid tensioned by leaf spring. The selected chamfering results obtained with this tool are discussed.
Źródło:
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika; 2017, z. 89 [295], 4; 469-478
0209-2689
2300-5211
Pojawia się w:
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sravnenije koehfficientov trenija skol'zhenija semjan i zhmykha l'na po poverkhnostjakh razlichnykh materiallov
Comparison of the sliding friction coefficient of linseed of oil varieties and linseed oil cake over the surface of different metals
Autorzy:
Kuzminskijj, R.
Sokolovskijj, O.
Vasilkevych, V.
Sheremeta, R.
Powiązania:
https://bibliotekanauki.pl/articles/77520.pdf
Data publikacji:
2015
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
sliding friction
linseed oil
flax seed
dry friction
friction coefficient
metal surface
Źródło:
Motrol. Motoryzacja i Energetyka Rolnictwa; 2015, 17, 4
1730-8658
Pojawia się w:
Motrol. Motoryzacja i Energetyka Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Właściwości tribologiczne węzłów ślizgowych zawierających elementy z warstwami powierzchniowymi modyfikowanymi borem
Tribological properties of sliding pairs containing elements with surface layers modified with boron
Autorzy:
Lubas, J.
Powiązania:
https://bibliotekanauki.pl/articles/263569.pdf
Data publikacji:
2009
Wydawca:
Sieć Badawcza Łukasiewicz. Przemysłowy Instytut Motoryzacji
Tematy:
bor
tarcie
węzły ślizgowe
właściwości tribologiczne
boron
friction
sliding pairs
tribological properties
Opis:
Właściwości tribologiczne węzłów ciernych zależą od ich konstrukcji, zastosowanych materiałów i przeprowadzonej obróbki powierzchniowej ich elementów. Celem badań było wyznaczenie wpływu modyfikacji borem warstwy powierzchniowej elementów, zastosowanych w parach kinematycznych pracujących warunkach tarcia ślizgowego. Badania porównawcze przeprowadzono za pomocą testera T-05 typu rolka-klocek. Dla realizacji programu badań wykonano próbki pierścieniowe z trzech gatunków stali: 38CrAlMo5-10, 46Cr2 i 30MnB4. Próbki te azotowano jonowo, borowano w proszku, borowano laserowo oraz pokryto powłoką TiB2. Próbki pierścieniowe skojarzone zostały w warunkach testu z przeciwpróbkami wykonanymi ze stopu łożyskowego AlSn20, a obszar tarcia smarowano olejem silnikowym Lotos syntetyczny 5W/40. Przeprowadzone badania wykazały, że warstwy powierzchniowe ulepszane cieplnie wpływają na obniżenie momentu tarcia podczas rozruchu, a jego maksymalne wartości są niższe od zmierzonych w skojarzeniach z warstwami azotowanymi. Najwyższe wartości współczynnika tarcia i temperatury w obszarze tarcia stwierdzono w parach z próbkami pierścieniowymi z warstwą borowaną laserowo. Natomiast największe zużycie stopu łożyskowego AlSn20 występuje w skojarzeniu z próbką z powłoką TiB2, a najniższe uzyskano w skojarzeniach z warstwami azotowanymi.
On the basis of the tests and the analysis of the obtained results, it was concluded that the boron-modified surface layers can be applicable in the slide pairs operating under mixed friction conditions, and their tribological properties are the effect of interaction between the surface layers of the slide pair elements and the lubricating oil. The surface layers of ring sample modified in the process of boronizing in powder with the AlSn20 bearing alloy are characterized by low friction resistance and temperature, which ensures that the slide pair has conducive conditions for a start-up and fast stabilization of the friction conditions. In turn, the laser-borided surface layer and the TiB2 layer causes intensive friction processes in the slide pair, which generates high friction resistance and high temperature and intensifies the processes of bearing alloy wear. It was stated that the use of 30MnB4 steel in the slide pairs after the hardening and tempering ensures similar work parameters and comparable level of wear of the bearing alloy, as in the application of 38CrAlMo5-10 steel with nitrided surface.
Źródło:
Archiwum Motoryzacji; 2009, 4; 297-305
1234-754X
2084-476X
Pojawia się w:
Archiwum Motoryzacji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Approximate formulation of the rigid body motions of an elastic rectangle under sliding boundary conditions
Autorzy:
Şahin, Önur
Erbaş, Barış
Wilson, Brent
Powiązania:
https://bibliotekanauki.pl/articles/1837937.pdf
Data publikacji:
2021
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
elastic rectangle
low frequency
rigid body motion
perturbation schemes
sliding boundary conditions
Opis:
Low-frequency analysis of in-plane motion of an elastic rectangle subject to end loadings together with sliding boundary conditions is considered. A perturbation scheme is employed to analyze the dynamic response of the elastic rectangle revealing nonhomogeneous boundary-value problems for harmonic and biharmonic equations corresponding to leading and next order expansions, respectively. The solution of the biharmonic equation obtained by the separation of variables, a consequence of sliding boundary conditions, gives an asymptotic correction to the rigid body motion of the rectangle. The derived explicit approximate formulae are tested for different kinds of end loadings together with numerical examples demonstrating the comparison against the exact solutions.
Źródło:
Acta Mechanica et Automatica; 2021, 15, 2; 82-90
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Finite-time integral sliding mode control for chaotic permanent magnet synchronous motor systems
Autorzy:
Chibani, A.
Daaou, B.
Gouichiche, A.
Safa, A.
Messlem, Y.
Powiązania:
https://bibliotekanauki.pl/articles/140698.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
chaos control
control chaotic Permanent Magnet Synchronous Motor
finite-time
sliding mode
Opis:
In this paper, an integral finite-time sliding mode control scheme is presented for controlling a chaotic permanent magnet synchronous motor (PMSM). The controller can stabilize the system output tracking error to zero in a finite time. Using Lyapunov’s stability theory, the stability of the proposed scheme is verified. Numerical simulation results are presented to present the effectiveness of the proposed approach.
Źródło:
Archives of Electrical Engineering; 2017, 66, 2; 229-239
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A fault monitoring method for wind power generation system based on sliding mode observer
Autorzy:
Yu, Wenxin
Huang, Shao Dao
Jiang, Dan
Powiązania:
https://bibliotekanauki.pl/articles/141570.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
double-fed induction generator (DFIG)
sliding model observer (SMO)
stator voltage-oriented
Opis:
In this paper, a rotor current fault monitoring method is proposed based on a sliding mode observer. Firstly, the state-space model of the Double-Fed Induction Generator (DFIG) is constructed by vector transformation. Meanwhile, the stator voltage orientation vector control method is applied to decouple a stator and rotor currents, so as to obtain the correlation between the stator and rotor current. Furthermore, the mathematical model of stator voltage orientation is obtained. Then a state sliding mode observer (SMO) is established for the output current of the rotor of the DFIG. The stability and reachability of the system in a limited time is proved. Finally, the system state is determined by the residuals of the measured and estimated rotor currents. The simulation results show that the method proposed in this paper can effectively monitor the status: a normal state, voltage drop faults, short-circuit faults between windings, and rotor current sensor faults which have the advantages of fast response, high stability.
Źródło:
Archives of Electrical Engineering; 2020, 69, 3; 625-643
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Observer design estimating the propofol concentration in PKPD model with feedback control of anesthesia administration
Autorzy:
Ilyas, Muhammad
Khan, Awais
Khan, Muhammad Abbas
Xie, Wei
Riaz, Raja Ali
Khan, Yousaf
Powiązania:
https://bibliotekanauki.pl/articles/2106507.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pharmacokinetic models
pharmacodynamic model
bispectral index monitor
observer design
sliding mode control
Opis:
Propofol infusion in anesthesia administration requires continual adjustment in the manual infusion system to regulate the hypnosis level. Hypnotic level is based on Bispectral Index Monitor (BIS) showing the cortical activity of the brain scaled between 0 to 100. The new challenging aspect of automation in anaesthesia is to estimate the concentration of hypnotic drugs in different compartments of the body including primary, rapid peripheral (muscle), slow peripheral (bones, fat) and effect site (brain) compartment based on Pharmacokinetics (PK) and Pharmacodynamics (PD) model. This paper aimed to regulate the hypnosis level with estimating the Propofol concentrations using a linear observer in feedback control strategy based on Integral Super-Twisting Sliding Mode Controller (ISTSMC). The drug concentration in plasma of the silico patients accurately estimated in nominal transient. The results show that tracking errors between the actual output in form of BIS level and linearized output nearly approaches to zero in the maintenance phase of anesthesia to ensure the controller response on sliding phase with optimum performances by achieving desired hypnotic level 50 on BIS. The robustness of control strategy is further ensured by adding measurement noise of electromagnetic environment of operation theatre distracting signal quality index of the output BIS level.
Źródło:
Archives of Control Sciences; 2022, 32, 1; 85--103
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł

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