自由浮动空间柔性机械臂在轨操作刚性载荷的组合控制

Composite Control of On-Orbit Operation of Free-floating Space Flexible Manipulator with Rigid Load

针对自由浮动空间柔性机械臂,讨论了在笛卡尔坐标系中机械臂对刚性载荷的轨迹跟踪控制和连杆柔性振动主动控制问题。基于拉格朗日法、假设模态法和系统动量守恒定律,推导了一种自由浮动空间柔性机械臂在轨操作刚性载荷的动力学方程。在此基础上,采用奇异摄动法将系统分解为慢变和快变两种尺度时标的子系统,设计模糊终端滑模控制器和Backstepping控制器分别对两个子系统进行控制,由此得到的组合控制使得机械臂按期望轨迹对刚性载荷进行精确在轨操作,同时抑制了柔性连杆的弹性振动。通过数字仿真验证了上述方法的有效性。

Aiming at a free-floating space flexible manipulator with a rigid load on-orbit, the trajectory tracking control of the load and an active vibration suppression of the flexible manipulator are studied in Cartesian space. On the basis of the assumed modes method, the Lagrange principle and the momentum conservation law, the dynamics modeling of a free-floating space flexible manipulator with a rigid load on-orbit is derived. Furthermore, a slow subsystem and a fast subsystem are separated based on the two-time scale singular perturbation method in which a fuzzy terminal sliding mode control method and a Backstepping control method are adopted in each subsystem respectively. Using this combined control method, the manipulator can track the expected trajectory accurately and its flexible vibration can be suppressed during manipulating the rigid load. Finally, the simulation results validate the effectiveness of the proposed method.