自由漂浮柔性空间机器人轨迹跟踪控制

Free-floating flexible space robot trajectory tracking

摘要:

引起针对自由漂浮柔性空间机器人的轨迹跟踪控制问题，利用拉格朗日和假设模态法建立了动力学模 型，综合考虑其欠驱动、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，考虑载体姿态干扰，提出一种改进自适应非奇异终端滑模控制策略，该方法采用自适应技术实时在线 学习扰动参数，并引入条件积分改进滑模面消除干扰的稳态误差，从而保证所设计的控制律对扰动具有 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．仿真结果表明该 控制策略对载体姿态干扰下系统轨迹跟踪控制的有效性和可靠性

Abstract:

The problem of trajectory tracking of a two-link free-floating flexible space robot is concerned in this paper. The dynamic equations of the robot are firstly developed by using Lagrange s principle with elastic vi- bration, and then they are transformed into a fully controllable form with the flexible vibration disturbance for the purpose of controller synthesis. By this simplified model, a robust control approach using adaptive non-sin- gular terminal sliding mode is developed, in which the dynamic uncertainty and disturbance can be eliminated via the online updating law, and the associated Lyapunov stability analysis are also investigated. Numerical simulation results show that the sliding mode is modified by adding a conditional integral to reduce the stable error in the present of attitude disturbance of a spacecraft