Trajectory Tracking Control Of Uncertain Wheeled Mobile Robots

With the rapid development of science technology,wheeled mobile robots(WMR)have gradually become the focus of research,which is not only provide support for the manufacturing,service industry,but also for the defense,aviation and other cutting-edge areas.In this paper,the research of uncertain trajectory tracking control is mainly focused on two aspects: the center of mass does not coincide with the geometric center,and the wheel longitudinal and lateral sliding.The main research work and achievements are as follows:The first part is based on the WMR kinematics model when the center of mass does not coincide with the geometric center,the control law is designed by the direct method of Lyapunov function,and the correctness of the method is verified.The second part is based on the WMR kinematic model of sliding,two aspects are studied.Firstly,for the WMR longitudinal sliding,a WMR kinematic model with two unknown sliding parameters is derived,and an adaptive control method is designed to compensate the longitudinal slip.Secondly,For longitudinal and lateral slippage,the robot kinematics model containing three unknown slip parameters is established.The three parameters are estimated by sliding mode observer,and t-he tracking controller is designed by Lyapunov stability theory and method.Then,the Lyapunov method is used to prove the stability of the two systems respectively.The simulation results show the effectiveness of the two control methods.The third part is based on the dynamic model when the centroid of WMR doesn't coincide its geometric centers,an adaptive neural sliding mode trajectory tracking control strategy is proposed.Firstly,an adaptive neural sliding mode dynamic controller is designed based on backstepping method and integral sliding mode control idea.