Postcapture stabilization of space robots considering actuator failures with bounded torques  

作　　者：Xiaokui YUE Teng ZHANG Honghua DAI Xin NING Jianping YUAN 

机构地区：[1]National Key Laboratory of Aerospace Flight Dynamics (AFDL), Northwestern Polytechnical University [2]School of Astronautics, Northwestern Polytechnical University [3]Department of Mechanical Engineering, University of Alberta

出　　处：《Chinese Journal of Aeronautics》2018年第10期2034-2048,共15页中国航空学报（英文版）

基　　金：co-supported by the National Natural Science Foundation of China (Nos. 11402200 and 11502203);the China Scholarship Council (CSC)

摘　　要：Space robotics is regarded as one of the most impressing approaches for space debris removal missions. Due to the residual momentum of debris, it is essential to stabilize the base rapidly after capture. This paper presents a novel control strategy for stabilization of a space robot in postcapture considering actuator failures and bounded torques. In the control strategy, the motion of the manipulator is not regarded as a disturbance to the base; in contrast, it is utilized to compensate for the limitation of the control torques by means of an inverse dynamical model of the system. Different scenarios where actuators are external mechanisms or momentum exchange devices have been carried out, and for actuator failures, both single-and two-actuator failures have been considered. Regarding to the performance of actuators, control torques are bounded. In cases that either single or two actuators have failed, the base can be stabilized kinematically when actuators are external mechanisms, but can only be stabilized dynamically when only momentum exchange devices are used. Finally, a space robot with a seven-degree-of-freedom manipulator in postcapture is studied to verify the validity and feasibility of the proposed control scheme. Simulation results show that the whole system can be stabilized rapidly.Space robotics is regarded as one of the most impressing approaches for space debris removal missions. Due to the residual momentum of debris, it is essential to stabilize the base rapidly after capture. This paper presents a novel control strategy for stabilization of a space robot in postcapture considering actuator failures and bounded torques. In the control strategy, the motion of the manipulator is not regarded as a disturbance to the base; in contrast, it is utilized to compensate for the limitation of the control torques by means of an inverse dynamical model of the system. Different scenarios where actuators are external mechanisms or momentum exchange devices have been carried out, and for actuator failures, both single-and two-actuator failures have been considered. Regarding to the performance of actuators, control torques are bounded. In cases that either single or two actuators have failed, the base can be stabilized kinematically when actuators are external mechanisms, but can only be stabilized dynamically when only momentum exchange devices are used. Finally, a space robot with a seven-degree-of-freedom manipulator in postcapture is studied to verify the validity and feasibility of the proposed control scheme. Simulation results show that the whole system can be stabilized rapidly.

关 键 词：Actuator failure Attitude control Bounded torque Postcapture Space robot 

分 类 号：V441[航空宇航科学与技术—飞行器设计] TP242[自动化与计算机技术—检测技术与自动化装置]