Trajectory Tracking Of Omnidirectional Mobile Robot Based On Active Disturbance Rejection Control

Recently,the technology of mobile robot has been developed rapidly.Mobile robots in resource exploration,space exploration,disaster search and other fields have become more and more widely used.Compared with the traditional wheeled mobile robot,the omni-directional mobile robot can move in any direction without changing the posture of the robot.Because of its high flexibility and mobility,OMR has attracted more and more attention of scholars both at home and abroad.In practical applications,the OMR is susceptible to various factors,such as external force disturbance,ground friction change and so on.How to realize the good trajectory tracking control of OMR becomes a difficult control problem.In this thesis,OMR is taken as the research object.The problems of OMR in the process of trajectory tracking in anti disturbance are studied.The active disturbance rejection control,passive control and sliding mode control theory are adopted.The main research contents are as follows:(1)Passivity based active disturbance rejection control for omnidirectional mobile robotsCombining passivity theory with active disturbance rejection control,a trajectory tracking control method for omnidirectional mobile robots is proposed.The method uses linear extended state observer to estimate system perturbation and external disturbance,and the controller is designed based on the theory of passivity,adding the disturbance compensation term in the controller,to achieve control of the mobile robot.The stability of the designed observer and controller system is analyzed,and the bounded input bounded output stability of the observation error and the exponential stability of the control error are proved.Finally,simulations and experiments are carried out,and the results show that the proposed method has strong anti-interference ability.(2)Sliding surface based active disturbance rejection control for omnidirectional mobile robotsIn order to further improve the estimation accuracy of the observer and improve the control performance of the mobile robot,the sliding surface is introduced into the observer,and the controller is still passive controller by exponential approach law.The asymptotic stability of the estimation error of the improved observer under certain conditions is given by Lyapunov theory.Finally,the performance of the proposed method is verified by simulation and experiments.Finally,this thesis summarizes the main content and main research results of this thesis,and looks forward to the improvement in the process of research.