针对轮式机器人的轨迹跟踪控制存在的问题,设计了一种改进非线性快速终端滑模控制器(improved nonlinear fast terminal sliding mode controller,INFTSMC)的控制方案.首先,通过对轮式机器人运动学的分析建立了轨迹跟踪误差模型;其次,在设计滑模控制器阶段,针对非线性快速终端滑模控制器存在奇异点,采用一种新的滑模面幂指数时变策略来设计非奇异终端滑模控制器,解决了非线性快速终端滑模控制器奇异问题,通过构造Lyapunov函数进行稳定性分析证明了该策略的稳定性,并且进行收敛时间分析给出系统从任意初始状态收敛至平衡点所需要的时间;然后,在新的滑模面幂指数时变策略的基础上设计了轮式机器人线速度和角速度控制律,使得轮式机器人轨迹跟踪误差快速收敛至0,实现了移动机器人对期望轨迹的快速跟踪.通过仿真实验与非线性快速终端滑模控制器和传统滑模控制其进行对比,验证了改进非线性快速终端滑模控制器的优越性.
Trajectory Tracking of Wheeled Robot Based on Improved Nonlinear Sliding Mode Control
Aiming at the problem of trajectory tracking control of wheeled robot,a control scheme of im-proved nonlinear fast terminal sliding mode controller is designed.Firstly,the trajectory tracking error model is established by analyzing the kinematics of wheeled robot.Secondly,in the stage of designing sliding mode controller,a new sliding mode surface power index time-varying strategy is adopted to design a non-singular terminal sliding mode controller,aiming at the singularity of nonlinear fast terminal sliding mode controller.The singularity problem of nonlinear fast terminal sliding mode controller is solved.The stability analysis of the strategy is proved by constructing Lyapunov function.The system convergence is analyzed and the time required for the system to converge from any initial state to the equilibrium point is given.Then,based on the new sliding mode surface power index time-varying strategy,the linear velocity and angular velocity control law of the wheeled robot is designed,which makes the tracking error of the wheeled robot quickly converge to 0,and realizes the fast tracking of the expected trajectory of the mobile robot.Finally,the advantages of the improved nonlinear fast terminal sliding mode controller are verified by simulation experiments compared with the nonlinear fast terminal sliding mode controller and the traditional sliding mode controller.
wheeled robottrajectory trackingfast terminal sliding mode controltime-varying power in-dexnon-singular sliding mode control
万方数据
维普
