Adaptive Control of Space Robot Despinning Tumbling Target Using Flexible Brushes

Shengxin Sun,Jianchun Lu,Cheng Wei,Yan Du,Zhuoran Huang,Hao Wu,Haibo Zhang

doi:10.1155/2021/6196556

Abstract

A flexible brush mechanism is designed and mounted at the end of a seven-degree-of-freedom robotic arm to despin a tumbling target. The dynamics model of the flexible brush is established using the absolute nodal coordinate method (ANCF), and its contact collision with the solar wing of the tumbling target is analysed. The H ∞ optimal control is proposed for a seven-degree-of-freedom robotic arm during despinning of a tumbling target while ensuring the global robustness and stability. Simulations verify that the despinning strategy can successfully eliminate the rotation speed and is feasible and effective.

Highlights

With the development of space technology, the number of human space satellites has gradually increased and the resulting space debris removal has become a key topic in the space industry [1]
In terms of contact despinning, Huang et al [4, 5] proposed a method for attitude control of noncooperative targets based on a tether terminal, which stabilizes the attitude of the tumbling target by controlling the tether tension and damping force attached to it; Daneshjou and Alibakhshi [6] proposed a spring damper buffer device which is accomplished by contact collision during nozzle docking in the despinning process; Nishida and Kawamoto [7] designed a despinning device with a flexible brush as the end-effector, which uses the elastic contact force between the brush and the target for despinning
For the stability of the deconvolution mechanism during the deconvolution process, the fast response and stability of the robotic arm are achieved by using sliding mode control

Summary

Introduction

With the development of space technology, the number of human space satellites has gradually increased and the resulting space debris removal has become a key topic in the space industry [1]. Kawamura et al [12] proposed a sliding mode control design based on a disturbance observer using Lyapunov’s stability theorem method, which reduces the gain of the switching term in the sliding mode controller and effectively eliminates jitter. Sun and Hou [17] studied the control problem of a flexible linkage robotic arm with uncertainty and proposed a sliding mode control method with both a neural network and a disturbance observer for adaptive design. By analysing Lyapunov stability, it can be demonstrated that in the case of bounded disturbances, the robust state feedback control term in the controller can effectively compensate for the uncertainties in the system and external disturbances, allowing the robot arm to accurately track the desired trajectory, i.e., the closed-loop system achieves asymptotic stability, while the quadratic performance index is optimal

Despin Dynamics

Spin Target Decontrol Study

Conclusions