空间机器人在轨双臂辅助航天器对接力/位置嵌套双层滑模阻抗控制  

Double layer sliding mode force/position impedance control for dual-arm space robot on orbit auxiliary docking spacecraft operation

作　　者：朱安 陈力[2] ZHU An;CHEN Li(School of Energy and Mechanical Engineering,Jiangxi University of Science and Technology,Nanchang 330013,China;School of Mechanical Engineering and Automation,Fuzhou University,Fuzhou 350108,China)

机构地区：[1]江西理工大学能源与机械工程学院,江西南昌330013 [2]福州大学机械工程及自动化学院,福建福州350108

出　　处：《光学精密工程》2023年第22期3266-3278,共13页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.51741502);福建省工业机器人基础部件技术重大研发平台资助项目(No.2014H21010011);福建省机器人基础部件与系统集成创新中心专项资金项目。

摘　　要：为了实现空间机器人捕获航天器及辅助对接操作的柔顺化,对航天器对接装置的输出力与位姿的精确控制进行了研究,且在关节电机与机械臂之间添加了弹簧阻尼缓冲装置,以防止接触、碰撞时产生的巨大冲击力造成关节破坏。首先,结合Newton第三定律、捕获点的速度约束及闭链系统的几何约束,获得了捕获航天器后的混合体系统动力学方程,通过动量守恒关系计算了碰撞冲击效应与冲击力。接着,通过航天器对接装置相对载体坐标系的运动学关系,建立了对接操作过程中的阻抗模型。然后,设计了一种鲁棒自适应双层滑模控制策略,其与阻抗控制相结合,采用力加载随动控制系统实现对接装置的位姿与输出力的精确控制,以降低接触、碰撞时的冲击力。该控制策略具有双层滑模结构,其第一层保证混合体系统在有限时间内收敛,第二层用于解决控制的高增益问题。最后,通过Lyapunov定理证明了系统的稳定性;利用数值仿真验证了所提控制策略的有效性。仿真结果表明,在给定的速度下缓冲装置最大可将碰撞冲击力矩降低46.78%,输出力的控制精度优于0.5 N,位置、姿态的控制精度优于10^(-3)m,0.5°。To comply with the process of a space robot capturing a spacecraft and the subsequent auxiliary docking operation,precise control of the output force and position of the spacecraft docking device was studied herein.A spring damper buffer device was added between the joint motor and manipulator to prevent the joint from being damaged under the huge impact force generated during contact and impact.First,by combining Newton's third law,velocity constraints of the capture points,and closed-chain system geometric constraints,a dynamic model of the hybrid system after capture was obtained,and the impact effect and force were estimated based on momentum conservation.Then,the impedance model during docking was established through the kinematics of the spacecraft docking device relative to the base coordinate system.Subsequently,a robust adaptive-double-layer sliding-mode control strategy was developed.Combined with impedance control,this strategy employed a force load servo control system to accurately control the position and output force of the docking device to reduce the impact force during contact and impact.The control strategy featured a double-layer sliding-mode structure,with the first layer ensuring convergence of the hybrid system in finite time and the second layer being used to solve the high-gain problem of the controller.Finally,the stability of the system was proved using the Lyapunov theorem,and the effectiveness of the proposed strategy was verified through a numerical simulation.The simulation results indicate that the buffer device can reduce the impact force by 46.78%of the maximum at the given velocities.Moreover,the control accuracy of the output force is better than 0.5 N,while the accuracies of the position and attitude are better than 10^(-3)m and 0.5°,respectively.

关 键 词：双臂空间机器人 缓冲装置 辅助对接操作 阻抗控制 双层滑模 

分 类 号：TP241[自动化与计算机技术—检测技术与自动化装置]