scholarly journals Switched Finite-Time Source Seeking of an Underactuated Ship

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yiwen Yang ◽  
Jingming Zhang ◽  
Yingjie Zhang
Keyword(s):  
Finite Time ◽  
Control Method ◽  
Angular Acceleration ◽  
Extremum Seeking ◽  
Signal Source ◽  
Underactuated Ship ◽  
Speed Controller ◽  
Source Seeking ◽  
Yaw Angle ◽  
First Time

In this paper, a switched finite-time source-seeking strategy is proposed for underactuated ships with a signal sensor. In practical application, for sensors in some complex environment, due to the lack of the ability to perceive the location of the source or its own position, we use the nonmodel gradient estimation of extremum seeking algorithm. This paper presents a three-step switching control method for the first time. In the first step, we prove that the closed-loop system of the underactuated ship is stable in a finite time with a constant yaw angular acceleration. In the second step, under the yaw angle acceleration controller, one of the position coordinates of the underactuated ship sensor is realized to be close to the center of the signal source through the average method. The third step is to drive the other position coordinates of the underactuated ship sensor to the center of the signal source under the action of the surge line speed controller. Simulation results show the effectiveness of the proposed strategy.

Robust finite-time trajectory tracking control for a space manipulator with parametric uncertainties and external disturbances

2021 ◽  
pp. 095441002110147
Author(s):  
Qijia Yao
Keyword(s):  
Trajectory Tracking ◽  
Finite Time ◽  
Tracking Control ◽  
Disturbance Observer ◽  
Control Method ◽  
Parametric Uncertainties ◽  
External Disturbances ◽  
Trajectory Tracking Control ◽  
Space Manipulator ◽  
Tracking Controller

Space manipulator is considered as one of the most promising technologies for future space activities owing to its important role in various on-orbit serving missions. In this study, a robust finite-time tracking control method is proposed for the rapid and accurate trajectory tracking control of an attitude-controlled free-flying space manipulator in the presence of parametric uncertainties and external disturbances. First, a baseline finite-time tracking controller is designed to track the desired position of the space manipulator based on the homogeneous method. Then, a finite-time disturbance observer is designed to accurately estimate the lumped uncertainties. Finally, a robust finite-time tracking controller is developed by integrating the baseline finite-time tracking controller with the finite-time disturbance observer. Rigorous theoretical analysis for the global finite-time stability of the whole closed-loop system is provided. The proposed robust finite-time tracking controller has a relatively simple structure and can guarantee the position and velocity tracking errors converge to zero in finite time even subject to lumped uncertainties. To the best of the authors’ knowledge, there are really limited existing controllers can achieve such excellent performance under the same conditions. Numerical simulations illustrate the effectiveness and superiority of the proposed control method.

scholarly journals Adaptive speed control method for electromagnetic direct drive vehicle robot driver based on fuzzy logic

2019 ◽  
Vol 52 (9-10) ◽  
pp. 1344-1353 ◽  
Author(s):  
Gang Chen ◽  
Weigong Zhang ◽  
Xu Li ◽  
Bing Yu
Keyword(s):  
Fuzzy Logic ◽  
Control Method ◽  
Tracking Error ◽  
Speed Control ◽  
System Structure ◽  
Direct Drive ◽  
Test Standards ◽  
Speed Controller ◽  
Fuzzy Neural ◽  
Vehicle Test

To solve the shortcomings of existing control methods for an electromagnetic direct drive vehicle robot driver, including large speed tracking error and large mileage deviation, a new adaptive speed control method for the electromagnetic direct drive vehicle robot driver based on fuzzy logic is proposed in this paper. The electromagnetic direct drive vehicle robot driver adapts an electromagnetic linear motor as its drive mechanism. The control system structure is designed. The coordinated controller for multiple manipulators is presented. Moreover, an adaptive speed controller for the electromagnetic direct drive vehicle robot driver is proposed to achieve the accurate tracking of desired speed. Experiments are conducted using a Ford FOCUS car. Performances of the proposed method, proportional–integral–derivative, and fuzzy neural network are compared and analyzed. Experimental results demonstrate that the proposed control method can accurately track the target speed, and it can inhabit the change of speed caused by interference under different test conditions, and it has small mileage deviation, which can meet the requirements of national vehicle test standards.

A novel robust finite-time tracking control of uncertain robotic manipulators with disturbances

2020 ◽  
pp. 107754632098244
Author(s):  
Hamid Razmjooei ◽  
Mohammad Hossein Shafiei ◽  
Elahe Abdi ◽  
Chenguang Yang
Keyword(s):  
Finite Time ◽  
Control Method ◽  
Sliding Mode ◽  
Robotic Manipulators ◽  
Sliding Mode Controller ◽  
Time Varying ◽  
State Variables ◽  
Terminal Sliding Mode ◽  
Control Laws ◽  
Finite Time Boundedness

In this article, an innovative technique to design a robust finite-time state feedback controller for a class of uncertain robotic manipulators is proposed. This controller aims to converge the state variables of the system to a small bound around the origin in a finite time. The main innovation of this article is transforming the model of an uncertain robotic manipulator into a new time-varying form to achieve the finite-time boundedness criteria using asymptotic stability methods. First, based on prior knowledge about the upper bound of uncertainties and disturbances, an innovative finite-time sliding mode controller is designed. Then, the innovative finite-time sliding mode controller is developed for finite-time tracking of time-varying reference signals by the outputs of the system. Finally, the efficiency of the proposed control laws is illustrated for serial robotic manipulators with any number of links through numerical simulations, and it is compared with the nonsingular terminal sliding mode control method as one of the most powerful finite-time techniques.

Variable Speed Vector Control for Induction Motor of Electric Vehicle

2014 ◽  
Vol 699 ◽  
pp. 759-764
Author(s):  
Amilia Emil Hasan ◽  
Haryani Hassan ◽  
Ismadi Bugis
Keyword(s):  
Embedded System ◽  
Vector Control ◽  
Induction Motor ◽  
Control Method ◽  
Torque Ripple ◽  
Electromagnetic Torque ◽  
Motor Speed ◽  
Speed Controller ◽  
Speed Performance ◽  
Constant Output

This paper presents the speed performance of an induction motor by using a vector control. The control scheme used is an indirect vector control for define speed command. The main focus of this research is to observe on the dynamic speed performance of the induction motor when the command speed is given to the motor. In this study, the system of indirect vector control will be built by using Matlab Simulink. In fact, the expression of exciting flux linkage and electromagnetic torque are used to create a simple embedded system which to find out the effects of flux weakening in motor while, the gain of the speed controller is 100. The result shows that the vector control method will cause immediate the motor speed response with a small electromagnetic torque ripple. Furthermore, the output mechanical torque starts to decrease when the motor speed above the base speed to maintain a constant output power operation. This paper contributes a new algorithm to analysis the system when the speed motor is higher than a base speed.

Visual servoing of dynamic wheeled mobile robots with anti-interference finite-time controllers

2018 ◽  
Vol 38 (5) ◽  
pp. 558-567 ◽  
Author(s):  
Hua Chen ◽  
Lei Chen ◽  
Qian Zhang ◽  
Fei Tong
Keyword(s):  
Mobile Robots ◽  
Finite Time ◽  
Visual Servoing ◽  
Control Method ◽  
External Disturbance ◽  
Nonholonomic Systems ◽  
Stability Control ◽  
Interference Control ◽  
Wheeled Mobile Robots ◽  
Content Type

Purpose The finite-time visual servoing control problem is considered for dynamic wheeled mobile robots (WMRs) with unknown control direction and external disturbance. Design/methodology/approach By using finite-time control method and switching design technique. Findings First, the visual servoing kinematic WMR model is developed, which can be converted to the dynamic chained-form systems by using a state and input feedback transformation. Then, for two decoupled subsystems of the chained-form systems, according to the finite-time stability control theory, a discontinuous three-step switching control strategy is proposed in the presence of uncertain control coefficients and external disturbance. Originality/value A class of discontinuous anti-interference control method has been presented for the dynamic nonholonomic systems.

scholarly journals Finite-Time Switching Control of Nonholonomic Mobile Robots for Moving Target Tracking Based on Polar Coordinates

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Hua Chen ◽  
Shen Xu ◽  
Lulu Chu ◽  
Fei Tong ◽  
Lei Chen
Keyword(s):  
Mobile Robots ◽  
Finite Time ◽  
Control Method ◽  
Tracking Error ◽  
Switching Control ◽  
Polar Coordinates ◽  
Control Law ◽  
Moving Target ◽  
Nonholonomic Mobile Robots ◽  
Time Switching

In this paper, finite-time tracking problem of nonholonomic mobile robots for a moving target is considered. First of all, polar coordinates are used to characterize the distance and azimuth between the moving target and the robot. Then, based on the distance and azimuth transported from the sensor installed on the robot, a finite-time tracking control law is designed for the nonholonomic mobile robot by the switching control method. Rigorous proof shows that the tracking error converges to zero in a finite time. Numerical simulation demonstrates the effectiveness of the proposed control method.

A finite-time H-infinite adaptive fault-tolerant controller considering time delay for flutter suppression of airfoil flutter

2019 ◽  
Vol 234 (2) ◽  
pp. 293-307
Author(s):  
Gao Ming-Zhou ◽  
Chen Xin-Yi ◽  
Han Rong ◽  
Yao Jian-Yong
Keyword(s):  
Finite Time ◽  
Control Method ◽  
Controller Design ◽  
Fault Tolerant ◽  
Linear Matrix ◽  
Control Methods ◽  
Actuator Faults ◽  
Control Delay ◽  
Modeling Uncertainties ◽  
The Stability

To suppress airfoil flutter, a lot of control methods have been proposed, such as classical control methods and optimal control methods. However, these methods did not consider the influence of actuator faults and control delay. This paper proposes a new finite-time H∞ adaptive fault-tolerant flutter controller by radial basis function neural network technology and adaptive fault-tolerant control method, taking into account actuator faults, control delay, modeling uncertainties, and external disturbances. The theoretic section of this paper is about airfoil flutter dynamic modeling and adaptive fault-tolerant controller design. Lyapunov function and linear matrix inequality are employed to prove the stability of the proposed control method of this paper. The numeral simulation section further proves the effectiveness and robustness of the proposed control algorithm of this paper.

Immersion and invariance adaptive finite-time control of air-breathing hypersonic vehicles

2018 ◽  
Vol 233 (7) ◽  
pp. 2626-2641 ◽  
Author(s):  
Chao Han ◽  
Zhen Liu ◽  
Jianqiang Yi
Keyword(s):  
Control System ◽  
Finite Time ◽  
Control Method ◽  
Sliding Mode ◽  
Second Order ◽  
Hypersonic Vehicles ◽  
Terminal Sliding Mode ◽  
Air Breathing ◽  
Immersion And Invariance ◽  
Time Control

In this paper, a novel adaptive finite-time control of air-breathing hypersonic vehicles is proposed. Based on the immersion and invariance theory, an adaptive finite-time control method for general second-order systems is first derived, using nonsingular terminal sliding mode scheme. Then the method is applied to the control system design of a flexible air-breathing vehicle model, whose dynamics can be decoupled into first-order and second-order subsystems by time-scale separation principle. The main features of this hypersonic vehicle control system lie in the design flexibility of the parameter adaptive laws and the rapid convergence to the equilibrium point. Finally, simulations are conducted, which demonstrate that the control system has the features of fast and accurate tracking to command trajectories and strong robustness to parametric and non-parametric uncertainties.

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