控制力矩受限情况下漂浮基柔性空间机械臂鲁棒自适应控制

Robust and Adaptive Control of Free-floating Flexible Space Manipulator with Bounded Control Torques

讨论控制力矩受限情况下,参数不确定的漂浮基柔性空间机械臂系统的智能控制问题。结合系统动量守恒关系和拉格朗日-假设模态法建立系统动力学方程。为了同时实现漂浮基柔性空间机械臂系统载体姿态和关节运动轨迹的渐近跟踪以及系统弹性振动的抑制,基于奇异摄动法将系统分解为快变和慢变两个子系统。针对快变子系统设计二次最优控制方法以抑制柔性臂引起的系统弹性振动,保证系统的稳定性;针对慢变子系统提出一种鲁棒自适应混合控制方法。该方法利用连续可导递增函数来限制控制力矩的幅值大小,使控制更符合空间实际要求;利用鲁棒自适应调节器来克服系统不确定参数的影响,保证系统的控制精度。计算机仿真结果证明了所提出方法的有效性。

The intelligent control problem of free-floating flexible space manipulator system with bounded control torques and uncertain parameters is studied.According to the momentum conservation and Lagrange-assumed mode method,the dynamic equation of the system is established.In order to realize the asymptotic trajectory tracking of the angles of the base’s attitude and the joints,and to suppress the system’s elastic vibration,the system is decomposed into a slow subsystem and a fast subsystem base on the singular perturbation approach.For the fast subsystem,a second optimization control is used to suppress the vibration of the flexible link,guarantee the system’s stability.For the slow subsystem,a robust and adaptive composite controller is designed.The proposed controller can limit the control torques effectively by the continuous differentiable increasing functions,which lets the controller more practical.And it can overcome the parametric uncertainty’s influence by use of robust and adaptive adjustment,so that it can guarantee the precision of the control system.The computer simulation results show the efficiency of the controller.