输入有界的自由漂浮柔性空间机器人轨迹跟踪控制

Trajectory-tracking control for free-floating flexible space robots with bounded inputs

针对自由漂浮柔性空间机器人轨迹跟踪控制问题,首先利用拉格朗日和假设模态法建立了动力学模型.分析系统动力学模型,综合考虑欠驱动、柔性振动等特点,将其简化为一种带有柔性振动扰动完全可控的动力学模型;在此基础上,考虑控制输入受限,提出一种自适应状态反馈控制策略.该策略采用自适应技术实时在线学习柔性振动扰动参数,从而保证控制律对柔性振动扰动具有良好的鲁棒性;最后,基于Lyapunov方法证明了该控制策略能够实现关节期望轨迹的跟踪.仿真验证了该控制策略对控制输入受限系统轨迹跟踪控制的有效性和可靠性.

This paper is concerned with the trajectory-tracking of free-floating flexible space robots. By means of La- grange＇s equations and the mode-assumption method, the dynamical equations of the space robot are derived and analyzed. These equations are transformed into a fully controllable form with the flexible vibration disturbance based on the char- acteristics of the underactuated dynamical control and the flexible vibration. In considering the physical limitations of the actuator, we develop a robust control approach with adaptive state feedback to reduce the uncertain dynamic disturbance. A complete analysis on the stability and the performance are performed by using Lyapunov theory. Simulation results of the application to a two-link free-floating flexible space robot show the feasibility of the proposed controller.