An Asymptotically Stable Control Scheme for Space Robot System

2018 ◽  
Vol 43 (12) ◽  
pp. 8049-8055
Author(s):  
Naveen Kumar
Keyword(s):  
Space Robot ◽  
Asymptotically Stable ◽  
Robot System ◽  
Control Scheme ◽  
Stable Control

Robust Variable Structure Control for Free-Floating Space Robot System With Dual-Arms in Joints Space

2009 ◽  
Author(s):  
Xiaoteng Tang ◽  
Li Chen
Keyword(s):  
Variable Structure Control ◽  
Variable Structure ◽  
Joint Space ◽  
Space Robot ◽  
Dynamic Equations ◽  
Robot System ◽  
Structure Control ◽  
Floating Base ◽  
Inertial Parameters ◽  
Control Scheme

In this paper, the kinematics and dynamics of free-floating space robot system with dual-arms are analyzed. It is shown that the dynamic equations of the system are nonlinearly according to inertial parameters. In order to overcome these problems, the system is modeled as under-actuated robot system, and the idea of augmentation approach is adopted. It is demonstrated that the dynamic equations of the system can be linearly depending on a group of inertial parameters. Based on this result, a robust variable structure control scheme for free-floating space robot system with dual-arms with uncertain inertial parameters to track the desired trajectories in joint space is proposed, and a planar space robot system with dual-arms is simulated to verify the proposed control scheme. The advantage of the control scheme proposed is that it requires neither measuring the position, velocity and acceleration of the floating base with respect to the orbit nor controlling the position and attitude angle of the floating base. In addition to this advantage, it is computationally simple, because of choosing the controller robust for the uncertain inertial parameters rather than explicitly estimating them online.

Self-Learning Control of Free-Floating Dual-Arm Space Robot Based on Fuzzy Adaptive Compensator

2009 ◽  
Author(s):  
Liang Jie ◽  
Chen Li
Keyword(s):  
Space Robot ◽  
Robot System ◽  
Loop Control ◽  
Inertial Space ◽  
Floating Base ◽  
Control Scheme ◽  
Adaptive Compensator ◽  
Dual Arm ◽  
Computed Torque ◽  
Fuzzy Adaptive

This paper discusses control problem of free-floating dual-arm space robot system with unknown payload parameters to track desired trajectory in inertial space, when the attitude of base is controlled and its location is uncontrolled. Combining the relationship of the linear momentum conversation and the Lagrange approach, the full-controlled dynamic equation and the Jacobian relation of free-floating dual-arm space robot are analysed and established. Based on the above results, for the case of free-floating dual-arm space robot system with unknown payload parameters, a composite control scheme is designed on the base of a computed torque controller and a fuzzy compensator to track desired trajectories in inertial space, i.e., balancing the effect of system unknown payload parameters on computed torque controller with fuzzy adaptive compensator, in order to ensure the whole closed-loop control system asymptotic stability with the existence of unknown payload parameters. The mentioned control scheme can effectively overcome the effect of system unknown payload parameters and control both the base attitude and the end-effector of dual-arm space robot, so that they can track the desired trajectory in inertia space, with obvious advantages neither the mentioned control scheme needs to measure and feedback the position, velocity and acceleration of the floating base, nor the mentioned control scheme needs to requirements for the dynamic equations of the system inertial parameters in linear function. A two planar dual-arm space robot system is simulated to verify the effectiveness of the proposed control scheme.

The Composite Adaptive Control of Free-Floating Space Robot System With Prismatic Joint

2001 ◽  
Author(s):  
Li Chen ◽  
Yanzhu Liu
Keyword(s):  
Adaptive Control ◽  
Jacobian Matrix ◽  
Jacobi Matrix ◽  
Space Robot ◽  
Robot System ◽  
Prismatic Joint ◽  
Inertial Parameters ◽  
Control Scheme ◽  
Generalized Jacobi Matrix ◽  
Composite Adaptive Control

Abstract In this paper, the kinematics and dynamics of a free-floating space robot system with prismatic joint are analyzed, and it is shown that the Jacobian matrix and the dynamic equations of the system cannot be linearly parameterized. With the augmentation approach, we demonstrate that the augmented generalized Jacobi matrix and the dynamic equation of the system can be linearly dependent on inertial parameters. Based on the results, the composite adaptive control scheme for a free-floating space robot with unknown inertial parameters to track the desired trajectory in workspace is proposed, and a two-link planar space robot system with prismatic joint is simulated to verify the proposed control scheme.

scholarly journals Reinforcement-Learning-Based Asynchronous Formation Control Scheme for Multiple Unmanned Surface Vehicles

2021 ◽  
Vol 11 (2) ◽  
pp. 546
Author(s):  
Jiajia Xie ◽  
Rui Zhou ◽  
Yuan Liu ◽  
Jun Luo ◽  
Shaorong Xie ◽  
...  
Keyword(s):  
Reinforcement Learning ◽  
Formation Control ◽  
Rapid Development ◽  
Gradient Algorithm ◽  
Robot System ◽  
Physical Relationship ◽  
Unmanned Surface Vehicles ◽  
Main Challenge ◽  
Control Scheme ◽  
Multi Robot

The high performance and efficiency of multiple unmanned surface vehicles (multi-USV) promote the further civilian and military applications of coordinated USV. As the basis of multiple USVs’ cooperative work, considerable attention has been spent on developing the decentralized formation control of the USV swarm. Formation control of multiple USV belongs to the geometric problems of a multi-robot system. The main challenge is the way to generate and maintain the formation of a multi-robot system. The rapid development of reinforcement learning provides us with a new solution to deal with these problems. In this paper, we introduce a decentralized structure of the multi-USV system and employ reinforcement learning to deal with the formation control of a multi-USV system in a leader–follower topology. Therefore, we propose an asynchronous decentralized formation control scheme based on reinforcement learning for multiple USVs. First, a simplified USV model is established. Simultaneously, the formation shape model is built to provide formation parameters and to describe the physical relationship between USVs. Second, the advantage deep deterministic policy gradient algorithm (ADDPG) is proposed. Third, formation generation policies and formation maintenance policies based on the ADDPG are proposed to form and maintain the given geometry structure of the team of USVs during movement. Moreover, three new reward functions are designed and utilized to promote policy learning. Finally, various experiments are conducted to validate the performance of the proposed formation control scheme. Simulation results and contrast experiments demonstrate the efficiency and stability of the formation control scheme.

scholarly journals Adaptive Stabilization Control for a Class of Complex Nonlinear Systems Based on T-S Fuzzy Bilinear Model

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Jinsheng Xing ◽  
Naizheng Shi
Keyword(s):  
Adaptive Control ◽  
Nonlinear Systems ◽  
Complex Systems ◽  
Closed Loop ◽  
Loop System ◽  
Asymptotically Stable ◽  
Bilinear Model ◽  
Closed Loop System ◽  
Fuzzy Modelling ◽  
Control Scheme

This paper proposes a stable adaptive fuzzy control scheme for a class of nonlinear systems with multiple inputs. The multiple inputs T-S fuzzy bilinear model is established to represent the unknown complex systems. A parallel distributed compensation (PDC) method is utilized to design the fuzzy controller without considering the error due to fuzzy modelling and the sufficient conditions of the closed-loop system stability with respect to decay rateαare derived by linear matrix inequalities (LMIs). Then the errors caused by fuzzy modelling are considered and the method of adaptive control is used to reduce the effect of the modelling errors, and dynamic performance of the closed-loop system is improved. By Lyapunov stability criterion, the resulting closed-loop system is proved to be asymptotically stable. The main contribution is to deal with the differences between the T-S fuzzy bilinear model and the real system; a global asymptotically stable adaptive control scheme is presented for real complex systems. Finally, illustrative examples are provided to demonstrate the effectiveness of the results proposed in this paper.

Sign in / Sign up

Export Citation Format

Share Document