不确定移动机械臂的反演滑模轨迹跟踪控制

Backstepping Sliding Mode Trajectory Tracking Control for Mobile Manipulator with Uncertanties

针对一类受复杂不确定影响下的非完整移动机械臂轨迹跟踪问题,建立包含模型误差和外界扰动的不确定动力学模型,提出一种基于反演设计的滑模控制方法。该方法首先采用输入-输出非线性反馈进行系统线性化,建立包含总体不确定性的等价系统;然后,基于李雅普诺夫直接法两步反演设计幂次趋近率滑模控制器,有效抑制系统有界不确定性,减小滑模抖振,保证闭环控制系统渐进收敛,从而实现对参考轨迹的快速精确跟踪。仿真结果表明,该方法跟踪速度快,精度高。

Trajectory tracking control is one of the key technologies for mobile manipulator to implement efficient task operation.In this paper,aiming at the trajectory tracking problem of a class of nonholonomic mobile manipulators under complex uncertainties,an uncertain dynamic model including model errors and external disturbances is established,and a sliding mode control method based inverse design is proposed.Firstly,the input-output non-linear feedback is used to linearize the system,and an equivalent system with global uncertainties is established.Then,based on Lyapunov direct method,a power reaching rate sliding mode controller is designed by two-step back-stepping.The bounded uncertainties of the system are effectively suppressed,the sliding mode chattering is reduced,and the asymptotic convergence of the closed-loop control system is guaranteed to achieve quick and accurate tracking of the reference trajectory.The simulation results demonstrate the effectiveness of this method.