Research On Control Strategy Of Wheeled Mobile Robot Problem Of Trajectory Tracking

Wheeled mobile robot is a non-linear,non-integrity-constrained,under-actuated system.The trajectory tracking problem of wheeled mobile robots is always a research hotspot.In recent years,scholars have obtained some research results in the field of trajectory tracking.However,the existing methods still have some problems that affect the performance of the tracker,such as the initial speed exceeding the robot speed constraint range,the parameter uncertainty and unmodeled interference of the robot dynamics modeling,and the emergence of the robot during the trajectory tracking process.Slip and slip phenomenon.This article has carried out research on the above-mentioned key problems in the design of the trajectory tracker of a wheeled mobile robot.The main contents are divided into the following aspects:(1)Aiming at the wheeled mobile robot with speed saturation constraint,a tracking scheme based on model predictive control is proposed.First,the kinematics virtual control speed is designed based on backstepping method.Then,considering its input and state constraints,a linear quadratic controller is designed to transform the quadratic optimal problem into a quadratic programming problem.Finally,simulation verification was performed to prove the effectiveness of the controller.(2)An adaptive dynamics control algorithm based on RBF neural network is proposed for a wheeled mobile robot with parameter uncertainty and unmodeled interference.First,the kinematics controller is designed by the backstepping method.Secondly,the PD controller is designed based on the dynamic model of the wheeled mobile robot,and the parametric and non-parametric uncertainties in the dynamic model are feed forward compensated by using the RBF neural network with automatic adjustment weights.Then the stability of the system is proved by Lyapunov function.Finally,simulation verification was performed to prove the effectiveness of the controller.(3)For a wheeled mobile robot with unknown sliding and slipping,a tracking control strategy based on the idea of active disturbance rejection is proposed.First,a dynamic model of the wheeled mobile robot under sliding and slipping conditions is established.Secondly,the kinematics controller is designed by the backstepping method.A linear expansion observer and a dynamic controller are designed based on the model,and the stability analysis of the system is given.Finally,a simulation comparison with integrated sliding mode control is performed,and the results show that the error convergence speed of the control method is faster.The observer can accurately estimate the disturbance of the robot from sliding and slipping and dynamic uncertainties,which improves the trajectory tracking of the wheeled mobile robot Robustness.