Tracking Control Of Mobile Robots

With the social development and progress of science and technology, wheeled mobile robot have been applied to many fields, such as manufacture, service, agriculture, detect and so on, which are able to perform some disgusting,heavy or harsh tasks historically assigned to human beings. The problem of wheeled mobile robot control have attracted more and more attention. In this thesis, we mainly concentrate on trajectory tracking for wheeled mobile robots. By employing backstepping and sliding mode variable structure method designe two new trajectory tracking laws are propsed based on kinematics model of the mobile robot.The improved trajectory tracking precision of the wheeled mobile robot is obtained. The main work and contributions of the thesis are summarized as follows:l.The nonholonomic constraints and nonholonomic system for wheeled mobile robots are introduced. The nonholonomics and controllability of the wheeled mobile robot are analyzed.The kinematic model and dynamic model of the mobile robot are established for the control law design and analysis.2.Basing on the kinematics model of the mobile robot, a baskstepping control is proposed.The global asymptotic stability is proven following Lyapunovs direct method. Simulation on a wheeled mobile robot demonstrate the effectiveness and improved performance of the proposed opproach.3.Integrating sliding mode technique into the backstepping control, an easy-going sliding mode control law is constructed, Lyapunovs direct method is used to prove global asymptotic tracking stability. Simulations are presented to demonstrate the effectiveness and correctness of the proposed method.