scholarly journals Dynamic Surface Adaptive Robust Control of Unmanned Marine Vehicles with Disturbance Observer

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Pengchao Zhang
Keyword(s):  
Robust Control ◽  
Disturbance Observer ◽  
Control Method ◽  
Three Dimensional ◽  
Lyapunov Stability Theory ◽  
Adaptive Robust Control ◽  
Dynamic Surface ◽  
Controlled System ◽  
Observer Error ◽  
Marine Vehicles

This paper presents a dynamic surface adaptive robust control method with disturbance observer for unmanned marine vehicles (UMV). It uses adaptive law to estimate and compensate the disturbance observer error. Dynamic surface is introduced to solve the “differential explosion” caused by the virtual control derivation in traditional backstepping method. The final controlled system is proved to be globally uniformly bounded based on Lyapunov stability theory. Simulation results illustrate the effectiveness of the proposed controller, which can realize the three-dimensional trajectory tracking for UMV with the systematic uncertainty and time-varying disturbances.

scholarly journals Adaptive Sliding Mode Robust Control for Virtual Compound-Axis Servo System

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Yan Ren ◽  
Zhenghua Liu ◽  
Le Chang ◽  
Nuan Wen
Keyword(s):  
Robust Control ◽  
High Frequency ◽  
Disturbance Observer ◽  
Position Control ◽  
Control Method ◽  
Sliding Mode ◽  
Tracking Error ◽  
Servo System ◽  
Adaptive Sliding Mode ◽  
Main System

A structure mode of virtual compound-axis servo system is proposed to improve the tracking accuracy of the ordinary optoelectric tracking platform. It is based on the structure and principles of compound-axis servo system. A hybrid position control scheme combining the PD controller and feed-forward controller is used in subsystem to track the tracking error of the main system. This paper analyzes the influences of the equivalent disturbance in main system and proposes an adaptive sliding mode robust control method based on the improved disturbance observer. The sliding mode technique helps this disturbance observer to deal with the uncompensated disturbance in high frequency by making use of the rapid switching control value, which is based on the subtle error of disturbance estimation. Besides, the high-frequency chattering is alleviated effectively in this proposal. The effectiveness of the proposal is confirmed by experiments on optoelectric tracking platform.

scholarly journals Adaptive robust control for free-floating space robot with unknown uncertainty based on neural network

2018 ◽  
Vol 15 (6) ◽  
pp. 172988141881151
Author(s):  
Zhang Wenhui ◽  
Li Hongsheng ◽  
Ye Xiaoping ◽  
Huang Jiacai ◽  
Huo Mingying
Keyword(s):  
Neural Network ◽  
Mathematical Model ◽  
Robust Control ◽  
Control Method ◽  
External Disturbance ◽  
Adaptive Robust Control ◽  
Lyapunov Theory ◽  
Space Robot ◽  
Neural Network Controller ◽  
The Stability

It is difficult to obtain a precise mathematical model of free-floating space robot for the uncertain factors, such as current measurement technology and external disturbance. Hence, a suitable solution would be an adaptive robust control method based on neural network is proposed for free-floating space robot. The dynamic model of free-floating space robot is established; a computed torque controller based on exact model is designed, and the controller can guarantee the stability of the system. However, in practice, the mathematical model of the system cannot be accurately obtained. Therefore, a neural network controller is proposed to approximate the unknown model in the system, so that the controller avoids dependence on mathematical models. The adaptive learning laws of weights are designed to realize online real-time adjustment. The adaptive robust controller is designed to suppress the external disturbance and compensate the approximation error and improve the robustness and control precision of the system. The stability of closed-loop system is proved based on Lyapunov theory. Simulations tests verify the effectiveness of the proposed control method and are of great significance to free-floating space robot.

Special Issue on Control Systems in Mechatronics

1996 ◽  
Vol 8 (3) ◽  
pp. 217-217
Author(s):  
Kiyoshi Ohishi ◽  
Keyword(s):  
Control System ◽  
Robust Control ◽  
Control Theory ◽  
Control Systems ◽  
Motion Control ◽  
Force Control ◽  
Disturbance Observer ◽  
Control Method ◽  
Mechanical Systems ◽  
Robust Control System

The special issue on Control Systems in Mechatronics is a significant and timely issue since many robotics and mechatronics engineers now pay attention to the research field of motion control and control theory. In Japan, advanced motion control technology is a key technics to improving the performance of robot systems and/or mechanical automation equipment. The definition of motion control in this issue is the control of mechanical systems driven by electrical actuators such as a do servo motor or an ac servo motor. The means or strategy of motion control has so far been of interest only to electrical engineers and mechanical engineers; it has not been as familiar to robotics engineers. Recently, a control system has been developed with industry applications. Advanced motor control technology in Japan is based on the robust control system, such as the disturbance observer, the H00 control system, the two-degrees-of-freedom control system and so on. The disturbance observer has a simple structure, and it is quite valid for disturbance torque rejection. The robust control system based on the disturbance observer is now widely used in robot and mechanical systems in Japan. The disturbance observer is the original Japanese technology designed by two electrical engineers, Prof. Ohnishi and myself, from the viewpoint of the electrical actuator but control theory. Ho control is linear control technics popular around the world. It can make the desired loop shaping of frequency characteristics for a plant system such as the actuator of a mechanical system. The robust control system based on the mixed sensitivity problem of H00 control theory has good frequency characteristics. Moreover, the availability of large amounts of computational power has enabled us to use complex control theory, and actuators for robotics applications are now mainly electrical ones because of the remarkable progress in power electronics. This change in the control of mechanical systems is a new and attractive one. Motion control is becoming a field of interest to control, electrical, and mechanical engineers who work in robotics. In this issue, the eight papers and the two news reports have been selected to show the current topics concerned with control systems in mechatronics. The first paper is a review paper titled ""robust motion control by the disturbance observer"". Prof. Ohnishi describes the physical meaning of motion control and the purpose of robust control. This review paper also shows the effectiveness of motion control based on the disturbance observer. Four papers in this issue deal with robot motion control systems using the disturbance observer. Mr. Oda explains the decoupling force control method of redundant robot manipulation by workspace disturbance observer which is not a joint space disturbance observer such as an ordinary disturbance observer. Dr. Komada explains the hybrid position/force control method based on second derivatives of position and force, which uses the force-based disturbance observer. Dr. Shimada explains the servo system considering a robot of low stiffness, which is based on the disturbance and velocity observer. This observer is mounted with each joint. Prof. Kuroe explains the decoupling control method of robot manipulation using a variable structure disturbance observer which is not an ordinary linear disturbance observer. The other three papers in this issue deal with robot motion control using the other advanced control system. Prof. Ohishi, myself explains the hybrid position/force control method without a force sensor, which is based on H00 acceleration controller and torque observer. This torque observer is the same observer as the ordinary disturbance observer. Mr. Fujimoto explains the three dimensional digital simulation of legged robots for advanced motion control. Mr. Kang explains the state estimation for mobile robots using a partially observable Markov decision process. This method can estimate the mobile robot state precisely and robustly. The two news reports in this issue deal with control and robot laboratory news from Japanese universities such as news generated by Prof. Hori of the University of Tokyo and Prof. Hori of Mie University. Both Prof. Horis are famous and active researchers in advanced motion control. This issue scans only one aspect of control systems, not the whole. Adaptive control, learning control, and other advanced control methods such as the LMI method are not mentioned. The subject of control systems in mechatronics is now expanding and developing. I greatly appreciate the efforts of the reviewers and authors in producing this issue, and I thank the Chief-Editor, Prof. Toshio Fukuda, for encouraging us to prepare it.

2A1-A06 Experiment on Catching an Object of UVMS Using Adaptive Robust Control method

2008 ◽  
Vol 2008 (0) ◽  
pp. _2A1-A06_1-_2A1-A06_4
Author(s):  
Shinichi SAGARA ◽  
Yuichiro Taira ◽  
Gaku Ohnishi ◽  
Masaharu Abe ◽  
Takashi Yatoh
Keyword(s):  
Robust Control ◽  
Control Method ◽  
Adaptive Robust Control

The control of the electro-hydraulic shaking table based on dynamic surface adaptive robust control

2016 ◽  
Vol 39 (8) ◽  
pp. 1271-1280 ◽  
Author(s):  
Wei Shen ◽  
Jun-zheng Wang ◽  
Shou-kun Wang
Keyword(s):  
Robust Control ◽  
Computational Cost ◽  
Adaptive Robust Control ◽  
Working Environment ◽  
Shaking Table ◽  
Parameter Uncertainties ◽  
Robust Controller ◽  
Dynamic Surface ◽  
Vibration Direction ◽  
And Control

The electro-hydraulic shaking table is investigated, in the present paper, to simulate the vibrational working environment of industrial components and equipment. Adaptive robust control can be applied to the shaking table system because electro-hydraulic systems suffer from internal parameter uncertainties and external disturbances. However, the adaptive robust controller design is complicated and has a large computational cost owing to the ‘explosion of terms’ problem. Thus dynamic surface control is applied in the design procedure of adaptive robust controllers to overcome the ‘explosion of terms’ problem. In this work, dynamic surface adaptive robust control is proposed. It simplifies the designed procedure of the controller and decreases its computational cost. Firstly, the structure of a shaking table is formulated and the operation principles of the shaking table, including the hydraulic and control principles, are analysed. A change is made in the mechanical-hydraulic system of the fluid circuit to address the problem of changing the vibration direction. Secondly, a dynamic model of a shaking table is proposed. Based on analysis of this model, the design of a dynamic surface adaptive robust controller for a shaking table is presented so as to improve its performance. Finally, comparative simulations and experiments are carried out. The comparison of performance results with proportional-integral-derivative control verify the correctness of the hydraulic scheme and control principle, as well as the high-performance of the dynamic surface adaptive robust controller. The shaking table achieves a guaranteed dynamical performance and tracking accuracy for the output in the presence of parameter and load uncertainties.

scholarly journals Adaptive Modified Function Projective Lag Synchronization of Uncertain Hyperchaotic Dynamical Systems with the Same or Different Dimension and Structure

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Xiuli Chai ◽  
Zhihua Gan ◽  
Chunxiao Shi
Keyword(s):  
Dynamical Systems ◽  
Chaotic System ◽  
Control Method ◽  
General Theorem ◽  
Three Dimensional ◽  
Lyapunov Stability Theory ◽  
Hyperchaotic System ◽  
Lag Synchronization ◽  
Projective Lag Synchronization ◽  
Hyperchaotic Systems

Modified function projective lag synchronization (MFPLS) of uncertain hyperchaotic dynamical systems with the same or different dimensions and structures is studied. Based on Lyapunov stability theory, a general theorem for controller designing, parameter update rule designing, and control gain strength adapt law designing is introduced by using adaptive control method. Furthermore, the scheme is applied to four typical examples: MFPLS between two five-dimensional hyperchaotic systems with the same structures, MFPLS between two four-dimensional hyperchaotic systems with different structures, MFPLS between a four-dimensional hyperchaotic system and a three-dimensional chaotic system and MFPLS between a novel three-dimensional chaotic system, and a five-dimensional hyperchaotic system. And the system parameters are all uncertain. Corresponding numerical simulations are performed to verify and illustrate the analytical results.

scholarly journals Linear Feedback Synchronization Used in the Three-Dimensional Duffing System

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Jian-qun Han ◽  
Xu-dong Shi ◽  
Hong Sun
Keyword(s):  
Feedback Control ◽  
Chaotic System ◽  
Control Method ◽  
Three Dimensional ◽  
Lyapunov Stability Theory ◽  
Linear Feedback ◽  
Nonlinear Feedback ◽  
Linear Feedback Control ◽  
Duffing System ◽  
Feedback Control Method

It has been realized that synchronization using linear feedback control method is efficient compared to nonlinear feedback control method due to the less computational complexity and the synchronization error. For the problem of feedback synchronization of Duffing chaotic system, in the paper, we firstly established three-dimensional Duffing system by method of variable decomposition and, then, studied the synchronization of Duffing chaotic system and designed the control law based on linear feedback control and Lyapunov stability theory. It is proved theoretically that the two identical integer order chaotic systems are synchronized analytically and numerically.

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