基于辅助变量的终端阻抗滑模六足机器人足端控制

Auxiliary variable based terminal sliding mode impedance control for hexapod robot feet

针对复杂环境下六足机器人足端力/位跟踪控制问题,提出一种基于辅助变量的终端阻抗滑模六足机器人足端控制方法来实现复杂环境下六足机器人的稳定运动。首先,该方法引入广义阻抗模型实现复杂环境下六足机器人足端位置和力的动态调节;其次,引入终端滑模控制方法提高系统的鲁棒性以及足端力/位跟踪误差收敛性能;然后,设计动态补偿器以及新型的辅助变量,构建桥梁,从而建立了结合终端滑模控制以及广义阻抗控制的复合控制框架;之后,通过Lyapunov理论证明了控制器的稳定性;最后,在六足机器人三自由度机械腿模型上与滑膜阻抗控制方法(SMIC)进行了对比仿真验证,仿真结果证明了与结合线性滑模面的滑模阻抗控制方法相比,所提控制方法具有更好的足端力/位跟踪精度以及更快的跟踪误差收敛速度。

In order to cope with the problem of feet force/position tracking control of the hexapod robot in complex environments,an auxiliary variable based terminal sliding mode impedance control for hexapod robot feet is proposed to achieve stable movement of the hexapod robot in complex environments.The generalized impedance model is adopted to dynamically adjust the position and force of the hexapod robot feet in complex environments.The terminal sliding mode control method is introduced to improve the robustness of the system and the convergence of foot force/position tracking error.The dynamic compensator and novel auxiliary variables are designed to construct a bridge,so as to establish a compound control framework that integrates terminal sliding mode control with generalized impedance control.The stability of the controller is proved by Lyapunov theory.Finally,the simulation results on the three-degree-of-freedom(3-DOF)mechanical leg model of the hexapod robot are contrasted with the sliding mode impedance control(SMIC)method.The simulation results show that the proposed control method has higher feet force/position tracking accuracy and faster tracking error convergence speed than the SMIC method combined with the linear sliding mode surface.