空间机械臂冲击动力学建模及冲击后运动控制

Modeling of Impact Dynamics and NN Control for Coordinated Motion of Space Manipulator

通过对漂浮基空间机械臂冲击动力学的建模,计算出完成抓取操作后空间机械臂各关节的运动速度,从而为数值仿真计算提供初始条件.针对目标物体及空间机械臂系统惯性参数存在未知的情况,设计了冲击后空间机械臂及目标物体组合系统的载体姿态及关节运动滑模神经网络控制,并对平面自由漂浮空间机械臂系统抓取目标物体的操作及冲击后控制进行了数值仿真.仿真结果表明,空间机械臂抓取目标物体时的冲击对系统有重大的影响,所设计的控制方案可保证系统对期望运动的追踪.

To simulate the post-impact dynamics, the velocities of base＇s attitude and each joint after impact are derived from the impact model. Based on the results and considering the uncertain parameters, the NN control using sliding mode is designed for the free-floating space manipulator. In particular, it doesn＇t require position measurement, velocity nor acceleration of the base because of an effective exploitation of the particular property of the system dynamics during the derivation of the system dynamic model in the post-impact phase. The numerical simulation carried out confirms that the controller proposed is feasible and effective.