基于鲁棒滑模观测器的两关节柔性机械手控制

Control for a two-link flexible manipulator based on the robust sliding-mode observer

中文关键词  观测器  柔性机械手  积分滑模

英文关键词  observer  flexible link manipulator  integral sliding mode

中文摘要

      柔性机械手系统为非最小相位系统, 当控制有界时, 该特性阻碍其端点位移渐近跟踪期望轨迹. 本文首先重新定义柔性机械手系统的输出, 通过输入输出线性化, 将系统分解为输入输出子系统和零动态子系统; 然后提出一种用于观测柔性模态导数的鲁棒滑模观测器, 使状态估计达到预期的指标, 解决了柔性模态导数难以获得的问题; 设计积分滑模控制策略, 使输入输出子系统在有限时间收敛到零; 选择适当的控制器参数, 使零动态子系统在 平衡点附近渐近稳定, 从而保证整个系统的渐近稳定. 本文提出的方法设计过程简单, 易于实现. 仿真结果证明了设计的有效性.

英文摘要

      Flexible manipulators system is a nonminimum-phase system. This characteristic hinders the asymptotic tracking of a desired tip trajectory with a bounded control input. The outputs of a a two-link flexible manipulator are redefined in dealing with this problem. First, the system is decomposed into input-output subsystem and zero dynamics systems by employing the input-output linearization, and then, a robust sliding mode observer is developed for generating the unmeasured derivative of the flexible modes. An integral sliding-mode control strategy is designed for the input-output subsystem to make them converge in a finite time. Moreover, the zero dynamics system can be asymptotically stable at the equilibrium point by properly adjusting controller parameters. Thus, the whole control system for the two-link flexible manipulator is guaranteed to be asymptotically stable. Furthermore, the control design procedure is simple and easy to be implemented. Simulation results validate the design.