Research On Motion And Path Following Control For Mobile Robot Based On RKP

In recent ten years,robotic technology has been developing rapidly.Wheeled mobile robot,as an important branch of mobile robot,is a hot research field and has been widely used in reqscue,military operations,factory and aerospace engineering.The study of the kinematic model of wheeled mobile robot is the premise of wheeled mobile robot control and prediction.Research on path following of wheeled mobile robots is an important condition for precise positioning and navigation.Wheeled mobile robot usually has complex structure.When establishing kinematic model of complex structure robot,the process of traditional modeling method is huge and the calculation efficiency is low.So a new kinematic modeling method is proposed,which improves the efficiency of kinematic model.Due to the slip of the mobile robot during the actual movement,including the slip of the main body of mobile robot,the longitudinal lateral slip of the wheel contact with ground,resulting in errors in following desired trajectory,thus decreasing the control accuracy of mobile robots.In order to improve the accuracy of path following with slip,a path following algorithm with slip compensation is proposed to improve the path following accuracy of wheeled mobile robots.This thesis mainly includes the following aspects:Firstly,forward and inverse kinematic model are established for wheeled mobile robot.The motion of wheeled mobile robots is abstracted as the motion of the manipulators.The method of establishing the kinematic model of the wheeled mobile robot is given.By recursively using the relative motion of the adjacent joint of wheeled mobile robot,the computing process is simplified and the motion state of the whole kinematic chain is obtained.Afterward,forward and inverse kinematic model are established for specific structure wheeled mobile robot,which can reflect the speed relationship between the robot body and the wheel,and lays a theoretical foundation for the motion control of the robot.And then,the correctness of the algorithm is verified by theory.Secondly,a path following algorithm with slip compensation is proposed.The traditional path following algorithm is no longer applicable because of the skidding,slip and steering slip of wheeled mobile robot during actual movement.To solve this problem,we need to establish a path following algorithm with slip compensation,and establish a stable and precise motion control system to ensure that the mobile robot can follow the desired trajectory.The control strategy using the front wheel to follow the trajectory and the rear wheel to compensate the slip.combined with the nonlinear control law to reduce the error of position and orientation angle.And theoretically proves that the algorithm can effectively reduce the error caused by skidding,slip and steering slip.Thirdly,in order to verify the effectiveness of the algorithm,through MATLAB simulation,the scheduled trajectory is complex curve,the wheeled mobile robot still can follow the desired path.Which shows the correctness and validity of the kinematics model established in this thesis.And the proposed path following algorithm with slip compensation can effectively reduce the error and improve the accuracy of path following.Finally,the validity of the algorithm is verified by the robot experiment platform.Through the hardware design,the power requirements and drive hardware selection of the robot are demonstrated.The motion control of the robot and the data acquisition of the encoder are realized by software design,which provides the experimental verification platform for the correctness of the algorithm.