柔性空间机械臂基于奇异摄动法的鲁棒跟踪控制和柔性振动主动控制

ROBUST CONTROL AND ACTIVE VIBRATION CONTROL OF SPACE FLEXIBLE MANIPULATOR BY SINGULAR PERTURBATION APPROACH

讨论了载体位置不受控、姿态受控情况下,具有不确定参数的漂浮基柔性空间机械臂关节轨迹跟踪鲁棒控制和柔性振动主动控制问题。利用拉格朗日方程和假设模态法并结合系统线动量守恒关系,对柔性空间机械臂系统进行动力学分析,发现所得到的动力学方程仍关于一组组合惯性参数保持惯常的线性函数关系。以此为基础,使用奇异摄动法和两种时间尺度的假设,将系统分解为轨迹跟踪控制器和振动控制器可分开设计的奇异摄动系统。对于快变子系统,使用全局最优控制来对柔性杆件的振动进行主动抑制。同时,针对系统参数不确定情况下,设计了鲁棒控制器来保证慢变子系统关节轨迹的跟踪。系统数值仿真结果证实了所设计控制器的有效性。

The robust control and active vibration suppression of a free-floating space flexible manipulator with an attitude-controlled base are studied. Combined the momentum conservation of the system, the dynamic equations are developed by using the Lagrangian method and assumed mode method. It is verified that the dynamic equations can be linearly dependent on a group of inertial parameters. Based on the results and under the assumption of two-time scale, a singular perturbation model of the space flexible manipulator system is obtained, then the controller can be designed separately to track desired trajectory and to suppress vibration. The fast subsystem controller will damp out the vibration of the flexible link using an optimal Linear Quadratic Regulator （LQR） method. The slow subsystem robust controller dominates the trajectory tracking of coordinated motion with uncertain system parameters. The numerical simulation is carried out, which confirms that the proposed controller is feasible and effective.