基于终端滑模控制的移动机器人轨迹跟踪

Trajectory tracking of mobile robot based on terminal sliding mode control

针对移动机器人受到外部不规则扰动时易出现速度和位姿误差跳变的问题,提出了一种基于扰动观测器的动态终端滑模控制方法。结合运动学模型,利用李雅普诺夫法设计虚拟控制器,进一步设计非奇异动态终端滑模轨迹跟踪控制器。为减小外部扰动对系统的影响,设计非线性扰动观测器对控制器进行扰动补偿。最后,将本文所提方法与自适应滑模控制方法进行仿真比较。结果显示,在第15 s扰动发生阶跃变化时,自适应滑模控制方法的线速度和角速度分别发生1.4 m/s和1.24 rad/s的跳变,而本文所提方法速度跳变幅度小于自适应滑模控制方法的1/10。仿真结果表明,本文所提方法可有效地抑制扰动对系统的影响,减小移动机器人速度和位姿误差的跳变幅度。

A dynamic terminal sliding mode control method based on disturbance observer is presented to solve the problem of speed and position error jump when a mobile robot is subject to external irregular disturbance.Based on the kinematics model,a virtual controller is designed using lyapunov method,and a non-singular dynamic terminal sliding mode track tracking controller is further designed.To reduce the influence of external disturbance on the system,a nonlinear disturbance observer is designed to compensate the disturbance of the controller.Finally,the method proposed in this paper is compared with the adaptive sliding mode control method by simulation.The results show that the line speed and angular speed of the adaptive sliding mode control method change by 1.4 m/s and 1.24 rad/s respectively when the 15 s disturbance changes step by step.The speed jump amplitude of the method presented in this paper is less than 1/10 of that of the adaptive sliding mode control method.The simulation results show that the proposed method can effectively suppress the influence of disturbance on the system and reduce the jump amplitude of the speed and posture errors of the mobile robot.