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Wyszukujesz frazę "Nonlinear Model" wg kryterium: Temat


Tytuł:
Generalization of Linear Rosenstark Method of Feedback Amplifier Analysis to Nonlinear One
Autorzy:
Borys, A.
Zakrzewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/226780.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
weakly nonlinear amplifiers
nonlinear Rosenstark model
nonlinear distortion analysis
harmonic distortion
constitutive equations
Volterra series
Opis:
Generalization of Linear Rosenstark Method of Feedback Amplifier Analysis to Nonlinear One This paper deals with an extension of the Rosenstark’s linear model of an amplifier to a nonlinear one for the purpose of performing nonlinear distortion analysis. Contrary to an approach using phasors, our method uses the Volterra series. Relying upon the linear model mentioned above, we define first a set of the so-called amplifier’s constitutive equations in an operator form. Then, we expand operators using the Volterra series truncated to the first three components. This leads to getting two representations in the time domain, called in-network and input-output type descriptions of an amplifier. Afterwards, both of these representations are transferred into the multi-frequency domains. Their usefulness in calculations of any nonlinear distortion measure as, for example, harmonic, intermodulation, and/or cross-modulation distortion is demonstrated. Moreover, we show that they allow a simple calculation of the so-called nonlinear transfer functions in any topology as, for example, of cascade and feedback structures and their combinations occurring in single-, two-, nd three-stage amplifiers. Examples of such calculations are given. Finally in this paper, we comment on usage of such notions as nonlinear signals, intermodulation nonlinearity, and on identification of transfer function poles and zeros lying on the frequency axis with related real-valued frequencies.
Źródło:
International Journal of Electronics and Telecommunications; 2014, 60, 1; 48-60
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A nonlinear statistical approach for damping uncertainty propagation in structural dynamics
Nieliniowe modelowanie statystyczne niepewności tłumienia w dynamice konstrukcyjnej
Autorzy:
Tiliouine, B.
Chemali, B.
Powiązania:
https://bibliotekanauki.pl/articles/230868.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dynamika konstrukcji
niepewność
odpowiedź dynamiczna
symulacja Monte Carlo
model nieliniowy
model statystyczny
structure dynamics
uncertainty
dynamic response
Monte Carlo simulation
nonlinear model
statistical model
Opis:
The object of the present study is to investigate the influence of damping uncertainty and statistical correlation on the dynamic response of structures with random damping parameters in the neighbourhood of a resonant frequency. A Non-Linear Statistical model (NLSM) is successfully demonstrated to predict the probabilistic response of an industrial building structure with correlated random damping. A practical computational technique to generate first and second-order sensitivity derivatives is presented and the validity of the predicted statistical moments is checked by traditional Monte Carlo simulation. Simulation results show the effectiveness of the NLSM to estimate uncertainty propagation in structural dynamics. In addition, it is demonstrated that the uncertainty in damping indeed influences the system response with the effects being more pronounced for lightly damped structures, higher variability and higher statistical correlation of damping parameters.
Nieliniowy Model Statystyczny (NLSM) jest opracowany, aby skutecznie rozpowszechniać niepewność tłumienia w analizach dynamicznych, w celu przewidywania statystyki drugiego rzędu dla probabilistycznej odpowiedzi konstrukcji ze skorelowanymi parametrami tłumienia. Waga tłumienia losowego ze skorelowanymi parametrami oraz ich wpływ na wrażliwość szczytowej odpowiedzi konstrukcyjnej, omawiane są w świetle znaczących zakresów niepewności tłumienia oraz współczynników korelacji. Dodatkowo, wpływ korelacji statystycznej tłumienia na granice przybliżenia Liniowego Modelu Statystycznego (LSM) oraz na NLSM badany jest za pomocą Symulacji Monte Carlo.
Źródło:
Archives of Civil Engineering; 2016, 62, 1; 11-24
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The identification method of the coal mill motor power model with the use of machine learning techniques
Autorzy:
Łabęda-Grudziak, Zofia Magdalena
Lipiński, Mariusz
Powiązania:
https://bibliotekanauki.pl/articles/2090698.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
coal mill motor power
nonlinear model identification
machine learning
additive regression models
process monitoring
moc silnika młyna węglowego
identyfikacja modelu nieliniowa
nauczanie maszynowe
model regresji addytywny
monitorowanie procesu
Opis:
The article presents an identification method of the model of the ball-and-race coal mill motor power signal with the use of machine learning techniques. The stages of preparing training data for model parameters identification purposes are described, as well as these aimed at verifying the quality of the evaluated model. In order to meet the tasks of machine learning, additive regression model was applied. Identification of the additive model parameters was performed on the basis of iterative backfitting algorithm combined with nonparametric estimation techniques. The proposed models have predictive nature and are aimed at simulation of the motor power signal of a coal mill during its regular operation, startup and shutdown. A comparative analysis has been performed of the models structured differently in terms of identification quality and sensitivity to the existence of an exemplary disturbance in the form of overhangs in the coal bunker. Tests carried out on the basis of real measuring data registered in the Polish power unit with a capacity of 200 MW confirm the effectiveness of the method.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2021, 69, 1; e135842, 1--9
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The identification method of the coal mill motor power model with the use of machine learning techniques
Autorzy:
Łabęda-Grudziak, Zofia Magdalena
Lipiński, Mariusz
Powiązania:
https://bibliotekanauki.pl/articles/2086819.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
coal mill motor power
nonlinear model identification
machine learning
additive regression models
process monitoring
moc silnika młyna węglowego
nieliniowa identyfikacja modelu
nauczanie maszynowe
model regresji addytywny
monitorowanie procesu
Opis:
The article presents an identification method of the model of the ball-and-race coal mill motor power signal with the use of machine learning techniques. The stages of preparing training data for model parameters identification purposes are described, as well as these aimed at verifying the quality of the evaluated model. In order to meet the tasks of machine learning, additive regression model was applied. Identification of the additive model parameters was performed on the basis of iterative backfitting algorithm combined with nonparametric estimation techniques. The proposed models have predictive nature and are aimed at simulation of the motor power signal of a coal mill during its regular operation, startup and shutdown. A comparative analysis has been performed of the models structured differently in terms of identification quality and sensitivity to the existence of an exemplary disturbance in the form of overhangs in the coal bunker. Tests carried out on the basis of real measuring data registered in the Polish power unit with a capacity of 200 MW confirm the effectiveness of the method.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2021, 69, 1; art. no. e135842, 1--9
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computationally efficient nonlinear model predictive controller using parallel particle swarm optimization
Autorzy:
Diwan, Supriya P.
Deshpande, Shraddha S.
Powiązania:
https://bibliotekanauki.pl/articles/2173694.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nonlinear model predictive control
particle swarm optimization
PSO
fast dynamic systems
rotary inverted pendulum
divide approach
conquer approach
kontrola predykcyjna modelu nieliniowa
optymalizacja roju cząstek
system dynamiczny szybki
wahadło obrotowe odwrócone
Opis:
As nonlinear optimization techniques are computationally expensive, their usage in the real-time era is constrained. So this is the main challenge for researchers to develop a fast algorithm that is used in real-time computations. This work proposes a fast nonlinear model predictive control approach based on particle swarm optimization for nonlinear optimization with constraints. The suggested algorithm divide and conquer technique improves computing speed and disturbance rejection capability, demonstrating its suitability for real-time applications. The performance of this approach under constraints is validated using a highly nonlinear fast and dynamic real-time inverted pendulum system. The solution presented through work is computationally feasible for smaller sampling times and it gives promising results compared to the state of art PSO algorithm
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 4; art. no. e140696
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficient MPC algorithms with variable trajectories of parameters weighting predicted control errors
Autorzy:
Nebeluk, Robert
Marusak, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/230077.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
model predictive control
nonlinear systems
nonlinear models
nonlinear control
simulation
optimization
Opis:
Model predictive control (MPC) algorithms brought increase of the control system performance in many applications thanks to relatively easily solving issues that are hard to solve without these algorithms. The paper is focused on investigating how to further improve the control system performance using a trajectory of parameters weighting predicted control errors in the performance function of the optimization problem. Different shapes of trajectories are proposed and their influence on control systems is tested. Additionally, experiments checking the influence of disturbances and of modeling uncertainty on control system performance are conducted. The case studies were done in control systems of three control plants: a linear non-minimumphase plant, a nonlinear polymerization reactor and a nonlinear thin film evaporator. Three types of MPC algorithms were used during research: linear DMC, nonlinear DMC with successive linearization (NDMC–SL), nonlinear DMC with nonlinear prediction and linearization (NDMC–NPL). Results of conducted experiments are presented in greater detail for the control system of the polymerization reactor, whereas for the other two control systems only the most interesting results are presented, for the sake of brevity. The experiments in the control system of the linear plant were done as preliminary experiments with the modified optimization problem. In the case of control system of the thin film evaporator the researched mechanisms were used in the control system of a MIMO plant showing possibilities of improving the control system performance.
Źródło:
Archives of Control Sciences; 2020, 30, 2; 325-363
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonlinear damage accumulation of concrete subjected to variable amplitude fatigue loading
Autorzy:
Chen, Y.
Chen, X.
Bu, J.
Powiązania:
https://bibliotekanauki.pl/articles/201230.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nonlinear damage
variable amplitude loading
prediction model
concrete
uszkodzenia
model predykcji
beton
Opis:
To account for the load sequence effect, damage fatigue models with nonlinearity in propagation and accumulation have been developed. This paper reviews five classical nonlinear fatigue models used to predict the life times of concrete under variable amplitude loadings. Experimental results from literature are used to validate the five classical prediction models. It can be found that Hilsdorf and Kesler model yields unsafe or conservative predictions, and the other four models are more suitable for predicting life times of concrete. In this paper, the author used a new nonlinear damage model based on the nonlinear continuum damage mechanics to predict fatigue life of concrete. The model considers fatigue limit, loading parameters, the unseparable characteristics for the damage parameter and the load sequence effect. The validity of the nonlinear fatigue damage model is checked against tests from literature.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2018, 66, 2; 157-163
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The application of Chaboche model in uniaxial ratcheting simulations
Autorzy:
Wójcik, Marta
Skrzat, A.
Powiązania:
https://bibliotekanauki.pl/articles/175730.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cyclic plasticity
ratcheting
Chaboche model
nonlinear kinematic hardening
isotropic hardening
Opis:
This article presents the application of Chaboche nonlinear kinematic hardening model in simulations of uniaxial ratcheting. First, the symmetrical strain-controlled cyclic tension/compression tests for PA6 aluminum samples were done. Using the experimental stress–strain curve, initial material hardening parameters were determined by the ABAQUS software. The experimental curve was compared with the numerical one. For better fitting of both curves, the optimization procedure based on the least-square method was applied. Using the determined hardening parameters, numerical simulations of the ratcheting were done by the finite element analysis software. Numerical results were then compared with the experimental data obtained in the stress-controlled cyclic loading test.
Źródło:
Advances in Manufacturing Science and Technology; 2020, 44, 2; 57-61
0137-4478
Pojawia się w:
Advances in Manufacturing Science and Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new predictive filter for nonlinear alignment model of stationary MEMS inertial sensors
Autorzy:
Alhassan, Hassan Majed
Ghahremani, Nemat Allah
Powiązania:
https://bibliotekanauki.pl/articles/2052163.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
predictive filter
nonlinear alignment
model error
optimization
MEMS inertial sensors
Opis:
This paper proposes a new approach called the Predictive Kalman Filter (PKF) which predicts and compensates model errors of inertial sensors to improve the accuracy of static alignment without the use of external assistance. The uncertain model error is the main problem in the field as the Micro Electro Mechanical System (MEMS) inertial sensors have bias which change over time, and these errors are not all observable. The proposed filter determines an optimal equivalent model error by minimizing a quadratic penalty function without augmenting the system state space. The optimization procedure enables the filter to decrease both model uncertainty and external disturbances. The paper first presents the complete formulation of the proposed filter. Then, a nonlinear alignment model with a large misalignment angle is considered. Experimental results demonstrate that the new method improves the accuracy and rapidness of the alignment process as the convergence time is reduced from 550 s to 50 s, and the azimuth misalignment angle correctness is decreased from 52′′ ± 47′′ to 4′′ ± 0.02′′.
Źródło:
Metrology and Measurement Systems; 2021, 28, 4; 673-691
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Salehs Model of AM/AM and AM/PM Conversions is not a Model without Memory : Another Proof
Autorzy:
Borys, A.
Powiązania:
https://bibliotekanauki.pl/articles/226188.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Saleh's model of AM/AM
Saleh's model of AM/PM
conversions
power amplifiers
memory effect
in-phase representation of nonlinear devices
quadrature representation of nonlinear devices
Opis:
The so-called Saleh's representation for description of the AM/AM and AM/PM conversions, occurring in communication power amplifiers, consists of two expressions that describe them as functions of a real-valued baseband signal modulating the carrier amplitude. It is a common view that this description forms a model without memory. We show here that the above belief is not correct; just the opposite is true. To prove this, we take into account an equivalent description of the Saleh's model called the quadrature model of bandpass nonlinearities and express it in a form of a nonlinear operator. Afterwards, we check whether this operator possesses a zero memory. To this end, we use an appropriate theorem of the nonlinear systems theory. Finally, as a result of this investigation, we observe that the memory of the above operator is nonzero.
Źródło:
International Journal of Electronics and Telecommunications; 2017, 63, 1; 73-77
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A robust model free controller for a class of SISO nonaffine nonlinear systems: Application to an electropneumatic actuator
Autorzy:
Boubakir, Ahsene
Labiod, Salim
Boudjema, Fares
Powiązania:
https://bibliotekanauki.pl/articles/229193.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dynamic inversion control
model free controller
nonaffine nonlinear systems
singular perturbation theory
Opis:
This paper presents a robust model free controller (RMFC) for a class of uncertain continuous-time single-input single-output (SISO) minimum-phase nonaffine-in-control systems. Firstly, the existence of an unknown dynamic inversion controller that can achieve control objectives is demonstrated. Afterwards, a fast approximator is designed to estimate as best as possible this dynamic inversion controller. The proposed robust model free controller is an equivalent realization of the designed fast approximator. The perturbation theory and Tikhonov’s theorem are used to analyze the stability of the overall closed-loop system. The performance of the developped controller are verified experimentally in the position control of a pneumatic actuator system.
Źródło:
Archives of Control Sciences; 2019, 29, 3; 437-458
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diagnosis of incipient faults in nonlinear analog circuits
Autorzy:
Deng, Y.
Shi, Y.
Zhang, W.
Powiązania:
https://bibliotekanauki.pl/articles/220611.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nonlinear circuits
fault diagnosis
Volterra series
fractional correlation
hidden Markov model (HMM)
Opis:
Considering the problem to diagnose incipient faults in nonlinear analog circuits, a novel approach based on fractional correlation is proposed and the application of the subband Volterra series is used in this paper. Firstly, the subband Volterra series is calculated from the input and output sequences of the circuit under test (CUT). Then the fractional correlation functions between the fault-free case and the incipient faulty cases of the CUT are derived. Using the feature vectors extracted from the fractional correlation functions, the hidden Markov model (HMM) is trained. Finally, the well-trained HMM is used to accomplish the incipient fault diagnosis. The simulations illustrate the proposed method and show its effectiveness in the incipient fault recognition capability.
Źródło:
Metrology and Measurement Systems; 2012, 19, 2; 203-218
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Offset-free nonlinear Model Predictive Control with state-space process models
Autorzy:
Tatjewski, P.
Powiązania:
https://bibliotekanauki.pl/articles/229638.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nonlinear control
predictive control
offset-free control
state-space model
state estimation
Opis:
Offset-free model predictive control (MPC) algorithms for nonlinear state-space process models, with modeling errors and under asymptotically constant external disturbances, is the subject of the paper. The main result of the paper is the presentation of a novel technique based on constant state disturbance prediction. It was introduced originally by the author for linear state-space models and is generalized to the nonlinear case in the paper. First the case with measured state is considered, in this case the technique allows to avoid disturbance estimation at all. For the cases with process outputs measured only and thus the necessity of state estimation, the technique allows the process state estimation only - as opposed to conventional approach of extended process-and-disturbance state estimation. This leads to simpler design with state observer/filter of lower order and, moreover, without the need of a decision of disturbance placement in the model (under certain restrictions), as in the conventional approach. A theoretical analysis of the proposed algorithm is provided, under applicability conditions which are weaker than in the conventional approach. The presented theory is illustrated by simulation results of nonlinear processes, showing competitiveness of the proposed algorithms.
Źródło:
Archives of Control Sciences; 2017, 27, 4; 595-615
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of an equivalent short solenoid model using different numerical methods
Autorzy:
Miron, O.
Desideri, D.
Micu, D.D.
Maschio, A.
Ceclan, A.
Czumbil, L.
Powiązania:
https://bibliotekanauki.pl/articles/140416.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
model solenoidu
problem nieliniowy
metoda numeryczna
metoda najmniejszych kwadratów
solenoid model
nonlinear problem
numerical methods
least squares
Opis:
This paper deals with an inverse magnetostatic problem related to the reconstruction of a permanent magnet encapsulated inside the cathode of a magnetron sputtering device. The numerical analysis is aimed to obtain the estimation of a short solenoid equivalent to the unknown magnet. Least squares approach has been used to solve the functional defined as squared sum of the residuals. A comparison of the results obtained with Genetic Algorithm approach and nonlinear system of equations is performed. A regularized solution, which is in good agreement with the experimental data, was found by applying a Newton adapted regularization technique.
Źródło:
Archives of Electrical Engineering; 2011, 60, 4; 433-444
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and experimentation of a self-tuning PID control applied to the 3DOF helicopter
Autorzy:
Boubakir, A
Labiod, S.
Boudjema, F.
Plestan, F
Powiązania:
https://bibliotekanauki.pl/articles/229575.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
3-DOF helicopter
PID control
adaptive control
MIMO nonlinear systems
model-free control
Opis:
The paper presents design and experimental validation of a stable self-tuning PID controller for three degrees of freedom (3-DOF) helicopter. At first, it is proposed a self-tuned proportional-integral-derivative (PID) controller for a class of uncertain second order multiinput multi-output nonlinear dynamic systems to which the 3-DOF helicopter dynamic model belongs. Within this scheme, the PID controller is employed to approximate unknown ideal controller that can achieve control objectives. PID controller gains are the adjustable parameters and they are updated online with a stable adaptation mechanism designed to minimize the error between the unknown ideal controller and the used by PID controller. The stability analysis of the closed-loop system is performed using Lyapunov approach. It is proven that all signals in the closed-loop system are uniformly ultimately bounded. The proposed approach can be regarded as a simple and effective model-free control since the mathematical model of the system is assumed unknown. Experimental results are presented to verify the effectiveness of the proposed controller.
Źródło:
Archives of Control Sciences; 2013, 23, 3; 311-331
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł

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