Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "underwater vehicle" wg kryterium: Temat


Wyświetlanie 1-11 z 11
Tytuł:
Correction of navigational information supplied to biomimetic Autonomous Underwater Vehicle
Autorzy:
Praczyk, T.
Powiązania:
https://bibliotekanauki.pl/articles/259696.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
underwater navigation
odometry
underwater vehicle
Opis:
In order to autonomously transfer from one point of the environment to the other, Autonomous Underwater Vehicles (AUV) need a navigational system. While navigating underwater the vehicles usually use a dead reckoning method which calculates vehicle movement on the basis of the information about velocity (sometimes also acceleration) and course (heading) provided by on-board devicesl ike Doppler Velocity Logs and Fibre Optical Gyroscopes. Due to inaccuracies of the devices and the influence of environmental forces, the position generated by the dead reckoning navigational system (DRNS) is not free from errors, moreover the errors grow exponentially in time. The problem becomes even more serious when we deal with small AUVs which do not have any speedometer on board and whose course measurement device is inaccurate. To improve indications of the DRNS the vehicle can emerge onto the surface from time to time, record its GPS position, and measure position error which can be further used to estimate environmental influence and inaccuracies caused by mechanisms of the vehicle. This paper reports simulation tests which were performed to determine the most effective method for correction of DRNS designed for a real Biomimetic AUV.
Źródło:
Polish Maritime Research; 2018, 1; 13-23
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The analysis of hydrodynamic forces and shape of towrope for an underwater vehicle
Autorzy:
Bielański, J.
Powiązania:
https://bibliotekanauki.pl/articles/258454.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
underwater vehicle
towrope
calculating forces
Opis:
The paper presents a method of calculating forces in an underwater vehicle towrope as well as its shape under the influence of hydrodynamic forces induced by water flowing round the towrope and vehicle. The rope hydrodynamic loads are calculated from the Morison’s equation and the vehicle forces and moments by means of coefficients. An example of calculations for a vehicle has been performed in the Matlab system for one towing speed.
Źródło:
Polish Maritime Research; 2007, S 2; 83-94
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinematical control of motion of underwater vehicle in horizontal plane
Autorzy:
Garus, J.
Powiązania:
https://bibliotekanauki.pl/articles/259399.pdf
Data publikacji:
2004
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
underwater vehicle
autopilot
fuzzy logic
Opis:
In the paper presented is a method of designing a fuzzy-logic-based autopilot for control of horizontal motion of an unmanned underwater vehicle. The control system’s synthesis was performed under the assumption that the vehicle can move with variable linear and angular velocities and the quantities possible to be measured are: position and orientaŹtion of the vehicle in the inertial reference system. The task of the autopilot was to minimiŹze the mean squares of deviations from the motion trajectory given in the form of a broken line defined by the coordinates of successive turning points. To generate control signals three independent fuzzy PD controllers using the control principles based on the Mac Vicar-Whelan’s standard base, were applied. For the linguistic variables of each controller appropriate fuzzy sets were selected and linear membership functions of trapezoidal and triangular form were defined. The presented results of the simulation tests performed for the remotely operated underwater vehicle "Ukwiał", with and without influence of disturbances resulting from sea current, confirm the proposed approach to be correct and effective.
Źródło:
Polish Maritime Research; 2004, 2; 27-31
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of effectiveness of waterjet propulsor for a small underwater vehicle
Autorzy:
Rowinski, Lech
Kaczmarczyk, Maciej
Powiązania:
https://bibliotekanauki.pl/articles/2033211.pdf
Data publikacji:
2021
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
ship propulsion
hydromechanics
waterjet
underwater vehicle
Opis:
The goal of the project described is to replace the existing propulsion system of a small underwater vehicle with a solution less prone to mechanical damage and ensuring a lower risk of the entanglement of fibrous objects suspended in the body of water. Four typical marine screws are utilised in the current design of the vehicle. One possible solution of the problem is the application of waterjet propulsors located inside the body of the vehicle instead. The general conditio of the application of the new solution was to secure at least the same motion control capabilities of the vehicle while the basic capability is its propulsion effectiveness at the required speed. Specific features of the considered waterjet propulsor, when compared with their application in surface vessel propulsion, are the lack of the head losses and the low significance of cavitation issues. One of the difficulties in the considered case is the small diameter of the propulsor in comparison to commercially available waterjet units, which have diameters between 0.1 [m] and 1.0 [m]. There is very little data regarding the design and performance of devices in the 0.02 to 0.05 [m] range. Methods utilised to forecast the performance of the new propulsion system are presented and results compared. These were semi-empirical calculations, numerical calculations and tests of real devices. The algorithm that is based on semi-empirical calculations is of particular interest while it offers possibility quick assessment of performance of a propulsor composed of several well defined components. The results indicate the feasibility of modification of the propulsion system for the considered vehicle if all the existing circumstances are taken into account.
Źródło:
Polish Maritime Research; 2021, 4; 30-41
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An algorithm for determining permissible control inputs to unmanned Underwater Robotic Vehicle (URV) fitted with azimuth propellers
Autorzy:
Garus, J.
Powiązania:
https://bibliotekanauki.pl/articles/259529.pdf
Data publikacji:
2005
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
underwater vehicle
propulsion system
azimuth propeller
control
Opis:
The paper deals with synthesis of automatic control system for an unmanned underwater robotic vehicle. The problem of determining permissible propulsive forces and moments necessary for optimum power distribution within a propulsion system composed of azimuth propellers (rotative ones). To allocate thrusts the unconstrained optimization method making it possible to obtain a minimum-norm solution, was applied. A method was presented for assessing propulsion system capability to generate propulsive forces (set control inputs). For the case of lack of such capability an algorithm was proposed making modification of their values and determination of feasible propulsive forces (i.e. permissible control inputs), possible. A numerical example which confirmed correctness and effectiveness of the proposed approach, was also attached.
Źródło:
Polish Maritime Research; 2005, 4; 26-31
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of fin’s material capabilities on the propulsion system of biomimetic underwater vehicle
Autorzy:
Piskur, Pawel
Szymak, Piotr
Kitowski, Zygmunt
Flis, Leszek
Powiązania:
https://bibliotekanauki.pl/articles/1573707.pdf
Data publikacji:
2020
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
fin flexibility
propulsion force
biomimetic underwater vehicle
fish-like movement
Opis:
The technology of Autonomous Underwater Vehicles (AUVs) is developing in two main directions focusing on improving autonomy and improving construction, especially driving and power supply systems. The new Biomimetic Underwater Vehicles (BUVs) are equipped with the innovative, energy efficient driving system consisting of artificial fins. Because these driving systems are not well developed yet, there are great possibilities to optimize them, e.g. in the field of materials. The article provides an analysis of the propulsion force of the fin as a function of the characteristics of the material from which it is made. The parameters of different materials were used for the fin design and their comparison. The material used in our research was tested in a laboratory to determine the Young’s modulus. For simplicity, the same fin geometry (the length and the height) was used for each type of fin. The Euler–Bernoulli beam theory was applied for estimation of the fluid–structure interaction. This article presents the laboratory test stand and the results of the experiments. The laboratory water tunnel was equipped with specialized sensors for force measurements and fluid–structure interaction analysis. The fin deflection is mathematically described, and the relationship between fin flexibility and the generated driving force is discussed.
Źródło:
Polish Maritime Research; 2020, 4; 179-185
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameters identification of the flexible fin kinematics model using vision and Genetic Algorithms
Autorzy:
Jurczyk, Karolina
Piskur, Paweł
Szymak, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/259505.pdf
Data publikacji:
2020
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
Biomimetic Underwater Vehicle
flexible fin kinematics model
parameters identification using vision
Genetic Algorithm
Opis:
Recently a new type of autonomous underwater vehicle uses artificial fins to imitate the movements of marine animals, e.g. fish. These vehicles are biomimetic and their driving system is an undulating propulsion. There are two main methods of reproducing undulating motion. The first method uses a flexible tail fin, which is connected to a rigid hull by a movable axis. The second method is based on the synchronised operation of several mechanical joints to imitate the tail movement that can be observed among real marine animals such as fish. This paper will examine the first method of reproducing tail fin movement. The goal of the research presented in the paper is to identify the parameters of the one-piece flexible fin kinematics model. The model needs further analysis, e.g. using it with Computational Fluid Dynamics (CFD) in order to select the most suitable prototype for a Biomimetic Underwater Vehicle (BUV). The background of the work is explained in the first section of the paper and the kinematic model for the flexible fin is described in the next section. The following section is entitled Materials and Methods, and includes a description of a laboratory test of a water tunnel, a description of a Vision Algorithm (VA)which was used to determine the positions of the fin, and a Genetic Algorithm (GA) which was used to find the parameters of the kinematic fin. In the next section, the results of the research are presented and discussed. At the end of the paper, the summary including main conclusions and a schedule of the future research is inserted.
Źródło:
Polish Maritime Research; 2020, 2; 39-47
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fault risk assessment of underwater vehicle steering system based on virtual prototyping and Monte Carlo simulation
Autorzy:
He, D.
Hu, N.
Hu, L.
Chen, L.
Guo, Y.
Chen, S.
Powiązania:
https://bibliotekanauki.pl/articles/260342.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
fault risk assessment
underwater vehicle
virtual prototyping
Monte Carlo simulation
steering system
fault simulation
Opis:
Assessing the risks of steering system faults in underwater vehicles is a human-machine-environment (HME) systematic safety field that studies faults in the steering system itself, the driver’s human reliability (HR) and various environmental conditions. This paper proposed a fault risk assessment method for an underwater vehicle steering system based on virtual prototyping and Monte Carlo simulation. A virtual steering system prototype was established and validated to rectify a lack of historic fault data. Fault injection and simulation were conducted to acquire fault simulation data. A Monte Carlo simulation was adopted that integrated randomness due to the human operator and environment. Randomness and uncertainty of the human, machine and environment were integrated in the method to obtain a probabilistic risk indicator. To verify the proposed method, a case of stuck rudder fault (SRF) risk assessment was studied. This method may provide a novel solution for fault risk assessment of a vehicle or other general HME system.
Źródło:
Polish Maritime Research; 2016, 3; 97-105
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Autonomous control of the underwater remotely operated vehicle in collision situation with stationary obstacle
Autorzy:
Śmierzchalski, Roman
Kapczyński, Maciej
Powiązania:
https://bibliotekanauki.pl/articles/32898218.pdf
Data publikacji:
2022
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
underwater vehicle
mini-ROV
collision avoidance
stationary obstacles
fuzzy logic
laser-based vision system
Opis:
The article considers the problem of autonomous control of the underwater remotely operated vehicle mini Remotely Operated Vehicle (ROV) in a collision situation with a stationary obstacle. The control of the collision avoidance process is presented as a synthesis of fuzzy proportional-differential controllers for the control of distance and orientation concerning the detected stationary obstacle. The control of the submergence depth of the underwater vehicle has been adopted as a separate control flow. A method to obtain the main motion parameters of the underwater vehicle relative to the detected stationary obstacle using a Laser-based Vision System (LVS) and a pressure sensor coupled to an Inertial Measurement Unit (IMU) is described and discussed. The result of computer implementation of the designed fuzzy controllers for collision avoidance is demonstrated in simulation tests and experiments carried out with the mini ROV in the test pool.
Źródło:
Polish Maritime Research; 2022, 4; 45-55
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Three-dimensional path-following control of an autonomous underwater vehicle based on deep reinforcement learning
Autorzy:
Liang, Zhenyu
Qu, Xingru
Zhang, Zhao
Chen, Cong
Powiązania:
https://bibliotekanauki.pl/articles/32898215.pdf
Data publikacji:
2022
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
autonomous underwater vehicle (AUV)
three-dimensional path following
deep reinforcement learning-based control
lineof-sight guidance
controller chattering
Opis:
In this article, a deep reinforcement learning based three-dimensional path following control approach is proposed for an underactuated autonomous underwater vehicle (AUV). To be specific, kinematic control laws are employed by using the three-dimensional line-of-sight guidance and dynamic control laws are employed by using the twin delayed deep deterministic policy gradient algorithm (TD3), contributing to the surge velocity, pitch angle and heading angle control of an underactuated AUV. In order to solve the chattering of controllers, the action filter and the punishment function are built respectively, which can make control signals stable. Simulations are carried out to evaluate the performance of the proposed control approach. And results show that the AUV can complete the control mission successfully.
Źródło:
Polish Maritime Research; 2022, 4; 36-44
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical model of flexible link dynamics in marine tethered systems considering torsion and its influence on tension force
Autorzy:
Trunin, Konstantin
Powiązania:
https://bibliotekanauki.pl/articles/32922104.pdf
Data publikacji:
2023
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
underwater tethered system
flexible links
rigidity
submersible vehicle
Opis:
The rigidity in bending of a flexible link (is an important characteristic that should be considered during regular service conditions. The tension and bending with torsion of wire ropes are also significant factors. This study proposed a method to calculate the vectors of the generalised forces of bending of flexible links. One of the causes of torsional stresses in the power plant of underwater tethered systems is the interaction with ship equipment, such as spiral winding on the winch drum, friction on the flanges of the pulleys or winch drums, and bends on various blocks and rolls that cause torsion. The source of torsional stresses in the FL may also be related to manufacturing, storage, transportation, and its placement on the ship’s winch drums. Torsion can lead to a decrease in the tensile strength due to load redistribution between power elements, or even a violation of their structure. In some cases, torsion significantly affects the movement of the underwater tethered system as a whole. The development of a mathematical model to describe the marine tethered systems dynamics, taking into account the effect of torsion, is important and relevant. The mathematical model of the marine tethered systems dynamics was improved and solved by accounting for the generalised forces of the torsion rigidity of the flexible link, using an algorithm and computer program. The influence of the bending and torsional rigidity of the FL on its deflection and tensile strength were considered based on the example of two problems. The developed program’s working window image shows the simulated parameters and the initial position of the flexible link. The results show that torsion has almost no effect on the shape of the a flexible link’s deflection in the X0Z plane, but leads to a deviation from the X0Z plane when calculating the static deflection of the flexible link. When the carrier vessel is stationary and the submersible vehicle has no restrictions on movement and has positive buoyancy, torsion leads to a three-dimensional change in the shape of the flexible link both in the X0Z plane and in the X0Y plane. The tension force of the flexible link along its length is distributed unevenly, and the torsion of the flexible link can lead to significant changes in its shape, the trajectory of towed objects, and the forces acting on the elements of the marine tethered systems.
Źródło:
Polish Maritime Research; 2023, 2; 188-196
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-11 z 11

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies