漂浮基空间机器人捕获卫星过程冲击动力学建模及基于非线性滤波器的镇定运动控制

摘要

The impact analysis of space robot while capturing a target and the stability control prob-lem after the impact were studied.Firstly, with the Lagrange equation, the dynamic model of space robot system was established and the dynamic model of the target was derived by Newton-Euler ap-proach.Secondly, the impact effect of rigid coupling model was analyzed by applying geometric rela-tionship and principle of momentum conservation.Output-feedback control scheme was designed for unstable combined system so as to stabilize the combined system.The input torque limited by the control law was designed for the condition of limited inputs with saturation function.The angle veloc-ity of the system was estimated by nonlinear filter and it only required the position measurement of the system.At last, the stability of the combined system was demonstrated by Lyapunov criteria. Numerical example was used to simulate the process of collision impact and the validity of the pro-posed control scheme was verified.%研究了空间机器人系统捕获目标卫星时发生碰撞的冲击效应及之后的稳定控制问题。首先利用拉格朗日第二类方程建立了空间机器人系统的动力学模型，目标物的动力学方程则通过牛顿欧拉法获得。其次利用运动几何关系及动量守恒原理，分析了碰撞冲击对系统的影响。对于两者接触后形成失稳的联合体系统，设计了输出反馈控制方案，以完成稳定控制。同时，考虑到空间机器人输入力矩有限的条件，运用带饱和函数的控制率将控制力矩限制在一定范围内。该方案利用非线性滤波器估测机械臂关节的速度，使其在控制过程中仅需测量系统位置信息。最后，通过李雅普诺夫判据证明了系统的稳定性。数值仿真实验模拟了碰撞冲击效应，并验证了上述控制方案的有效性。