面向未知目标的柔性关节空间机器人滑模控制

针对载荷捕获的空间机器人控制问题，同时考虑机械臂关节柔性和非合作目标质量未知等因素影响，提出一种基于目标质量观测器的滑模变结构控制方法.首先，针对空间非合作目标质量未知问题，设计基于改进的最小二乘迭代算法实现对非合作目标质量在线辨识.进而，采用拉格朗日方法和动量矩守恒原理，建立漂浮基座柔性关节空间机器人动力学模型；针对动力学模型中刚柔耦合特性，基于奇异摄动理论将系统模型近似地分解为快慢变子系统；针对慢变子系统，设计滑模变结构控制器来保证系统的鲁棒性和动态特性；针对快变子系统，设计基于速度差值的反馈补偿控制算法，抑制柔性关节产生的残余振动，保证控制精度.最后，实验分析了快慢变子系统各自的作用机理，验证了控制方法有效性.

Sliding Mode Control of Flexible Joint Space Robot for Unknown Target

Aiming at the control problem of space robot with load capture, a sliding mode variable structure control method based on target mass observer is proposed, considering the joint flexibility of manipulator and the unknown mass of non cooperative target. Firstly, aiming at the problem of unknown quality of space non cooperative target, an improved least square iterative algorithm is designed to realize on line identification of non cooperative target quality. Then, the dynamic model of flexible joint space robot on floating base is established by using Lagrange method and the principle of moment of momentum conservation. According to the rigid flexible coupling characteristics of the dynamic model, the system model is approximately decomposed into fast and slow varying subsystems based on singular perturbation theory. For the slow varying subsystem, the sliding mode variable structure controller is designed to ensure the robustness and dynamic characteristics of the system. For the fast changing subsystem, the feedback compensation control algorithm based on the speed difference is designed to suppress the residual vibration of the flexible joint and ensure the control accuracy. Finally, the mechanism of fast and slow subsystems is analyzed by experiments, and the effectiveness of the control method is verified.