基于位置约束的两轮驱动机器人路径跟踪控制方法

Path tracking control method for a two-wheel-drive robot based on position constraints

两轮驱动机器人的应用越来越广泛,但由于两轮驱动机器人属于欠驱动系统,输入量不能使机器人按任意轨迹运动,因此较难控制。针对两轮驱动机器人的路径跟踪控制问题,分析了两轮驱动机器人运动模型,提出了一种新的路径跟踪控制方法。通过左右轮的双闭环PID控制来约束两轮机器人的速度和位姿,同时,在期望路径附近建立矢量场,引入位置约束,促使两轮机器人在偏离期望路径时能够快速回归,完成路径跟踪任务。搭建了两轮驱动机器人硬件实验平台,实现了两轮驱动机器人的路径跟踪控制。实验结果表明,两轮驱动机器人能够准确跟踪期望路径,对于设置的一种较复杂路径跟踪实验,得出的各跟踪点的相对误差的均方差为0.86%,最大相对误差为3.64%。

Nowadays two-wheel-drive robots become more and more widely used.As an underactuated system,however,it cannot track any arbitrary trajectory,which makes it very difficult to control.Aiming at this problem,a new path tracking solution is proposed by analyzing its dynamic model.In this solution,a dual-loop PID controller is designed for both left and right wheels in order to achieve a desired velocity and pose.Meanwhile,a vector field is specifically built based on any given path so that the two-wheel-drive robot can return quickly once it deviates from the desired path.Finally,a hardware experimental platform is built,and several practical experiments are successfully implemented.For a relatively complex situation, the tracking result shows that the mean square deviation is 0.86% and the maximum relative error is 3.64%, which validates the proposed method.