空间机器人捕获卫星操作基于柔顺装置的无源模糊避撞柔顺控制

讨论了漂浮基空间机器人在轨捕获非合作卫星过程避免关节受冲击及过载破坏的避撞柔顺控制问题。在关节电机与机械臂之间配置了一种柔顺装置——旋转型串联弹性执行器(RSEA),其作用一是在捕获阶段,通过其内置弹簧的变形来缓冲捕获过程中被捕获卫星对空间机器人关节产生的冲击能量;二是在捕获完成后的镇定运动阶段,结合所设计的避撞柔顺策略来适时开关关节电机以保证关节冲击力矩受限在安全范围。首先,根据拉格朗日法及牛顿-欧拉法分别建立了含柔顺装置空间机器人与目标卫星系统的动力学方程;之后,结合整个系统动量守恒关系、系统运动几何及位置约束关系,建立了捕获操作后两者形成混合体系统的动力学方程。在此基础上,针对捕获操作后不稳定的混合体系统,提出了一种基于无源性理论的避撞柔顺模糊控制方案以实现其镇定控制。最后,通过仿真实验验证了所提避撞柔顺策略的有效性。

Collision avoidance and compliant passive fuzzy control of space robot based on compliant mechanism capture a satellite

The problem of collision avoidance compliant control for a free-floating space robot to protect its joints due to impact in the process of capturing non-cooperative spacecraft is discussed.For this purpose,a Rotary Series Elastic Actuator (RSEA) is mounted between the joint motor and manipulator.Its functions are:first,the deformation of its internal spring can absorb and buffer the impact energy on the joints of the space robot caused by the captured spacecraft during the capture collision phase.Second,in the stabilization stage of post-capture,the joint impact torque can be limited to a safe range by combining the collision avoidance compliant control scheme.According to the Lagrange approach and Newton-Euler method,the system dynamics equation of space robot and the satellite are obtained.After that,based on the law of conservation of momentum,the constraints of kinematics and geometric constraints of the position,the integrated dynamic model of the composite system is derived.On that basis,in order to calm control of the post-capture unstable composite system,a collision avoidance compliant fuzzy control scheme based on passivity theory is proposed.Finally,the effectiveness of the proposed collision avoidance compliant control strategy is verified by simulation experiments.