基于变结构的移动机器人侧向控制器的设计

采用基于后推与模糊滑模控制相结合的方法设计了移动机器人的变结构状态反馈控制器,实现了对道路跟踪侧向误差的渐近镇定控制.应用Lyapunov定理推导了移动机器人满足非完整性约束的时变光滑状态反馈镇定控制律;将状态控制区域分为远离奇异点的稳定工作区域与含有奇异点的非稳定区域2部分.设计模糊控制嚣来控制移动机器人的状态从非稳定区域向稳定区域转变,并采用移动机器人Amigobot作为实验平台验证了控制器设计的有效性.研究结果表明:侧向误差较大时,模糊控制器确保移动机器人在稳定区域内沿着模态切换线减小误差;当侧向误差较小时,时变光滑状态反馈控制实现对移动机器人的平稳镇定.在控制器设计中,将移动机器人的平移速度视为渐变参数,根据侧向误差能量函数的变化进行模糊自适应调节.

Design of lateral controller based on variable structure for a mobile robot

This paper designs a nonlinear variable structure control system based on backstepping technique and fuzzy sliding mode control for asymptotic stabilization during the path tracking. A time-varying smooth state feedback controller is derived from Lyapunov theory and singular points of controller are analyzed. The control area of state is divided into stable working area which is remote from singular points and the non-stable area including singular points. A fuzzy controller is designed to force the state of robot transform from non-stable area to stable area. When existing a large lateral error, the fuzzy controller decreases the lateral error by controlling the mobile robot moves along the stable area. The time-varying smooth state feedback controller can stabilize the robot evenly with a small error. The translation-velocity is regarded as the asymptotic changed parameter and controlled by the fuzzy controller according to the varying of the lateral error function. The variable structure controller can be verified with the Amigobot.