摘要
研究了空间机器人在轨捕获非合作卫星过程避免关节受碰撞冲击破坏的缓冲从顺控制问题,为此在机械臂与关节电机之间配置了一种柔性机构,其作用在于:(1)在接触、碰撞阶段可通过其内置弹簧的变形来吸收被捕获卫星对空间机器人关节产生的冲击力矩;(2)在镇定运动阶段,结合与之配合的缓冲从顺控制策略来适时开、关关节电机,以保证关节受到的冲击力矩受限在安全范围.首先,利用多刚体系统理论获得配置柔性机构空间机器人及目标卫星分体系统动力学方程;之后,结合整个系统动量守恒关系,捕获操作后系统运动几何关系及力的传递规律,建立了两者形成联合体系统的动力学方程,并计算了碰撞过程的冲击效应与冲击力.为了实现失稳联合体系统的镇定控制,提出了一种基于动态面的缓冲从顺控制方案.上述控制方案可在实现吸收捕获操作产生的冲击力矩的同时,还能在冲击力矩过大时适时开启、关闭关节电机,以避免关节电机发生破坏;此外,动态面的引入避免了反演法存在的计算膨胀问题,有效减少了计算量.基于Lyapunov函数法证明了系统的稳定性,并通过系统数值仿真结果验证了上述缓冲从顺控制策略的正确性.
The buffer and compliant control for space robot to avoid joint damage during on-orbit capture non-cooperative satellite are studied. For the reason, a compliant mechanism is mounted between the joint motor and space manipulator,its functions are: first, the deformation of internal spring in compliant mechanism can absorb the impact torque of the captured satellite acting on the joint of the space robot;second, the joint impact torque can be limited to a safe range by reasonably designing the buffer and compliant control scheme. First of all, the dynamic models of the space robot system and the target satellite system before capture are derived by multi-body theory. After that, based on the law of conservation of momentum, the constraints of kinematics and the law of force transfer, the integrated dynamic model of the combined system is derived. At the same time, the impact effect and impact force are calculated. For the stabilization control of post-capture unstable combined system, a buffer and compliant control scheme based on dynamic surface is proposed.The proposed control scheme can not only effectively absorb the impact torque generated by the on-orbit capture process,but also timely open or close the joint motor when the impact torque is too large, which can avoid overload and damage of the joint motor. In addition, the dynamic surface control scheme is utilized to avoid calculation expansion caused by backstepping method and to reduce the calculation effectively. The stability of the system is proved by Lyapunov theorem,and numerical simulation verifies the effectiveness of the proposed buffer and compliant control method.
作者
艾海平
陈力
Ai Haiping;Chen Li(School of Mechanical Engineering and Automation,Fuzhou University,Fuzhou 350116,China)
出处
《力学学报》
EI
CSCD
北大核心
2020年第4期975-984,共10页
Chinese Journal of Theoretical and Applied Mechanics
基金
国家自然科学基金(11372073,51741502)
福建省工业机器人基础部件技术重大研发平台(2014H21010011)资助项目。
关键词
柔性机构
空间机器人
捕获操作
缓冲从顺控制
动态面控制
compliant mechanism
space robot
capture satellite operation
buffer and compliant control
dynamic surface control
