Anti-disturbance Trajectory Tracking Control Of Non-holonomic Mobile Robot Based On State Observer

Non-holonomic mobile robots,as an important branch of robots,are the critical research object for many researchers due to the wide application in many fields such as industry,medical treatment and agriculture.In the problem of trajectory tracking control for non-holonomic mobile robots,it is expected that they can perform the path tracking task based on the planned trajectory.However,tracking errors often occur in the movement process,which is owing to the influence of the external environment(complex terrain,etc.)and the internal system(quality,friction,etc.),as well as the failure to consider the dynamics of modeling and the disturbance of unknown parameters in the design.This thesis takes wheeled mobile robots as the research object and establishes mathematical models of the wheeled mobile robot,including the model of kinematics and dynamics.The kinematic control law is obtained by utilizing the backstepping method,selecting proper Lyapunov function.Secondly,the stability of the law is analyzed.And then the feasibility of the kinematics control law is verified with numerical simulation.But in the actual movement of the wheeled mobile robot,the accuracy of the trajectory tracking control of the mobile robot is reduced because of the perturbation of the system parameters,unmodeled dynamics and external disturbances.So the mobile robot control system has obvious deviations.In order to effectively suppress this deviation,a trajectory tracking control method based on the extended state observer is designed.In this method,a dynamic model considering external disturbances is established.And the disturbance observer based control is used to estimate and to deal with the uncertainty in the system.Finally,the trajectory tracking control law of the model is designed.The designed wheeled mobile robot trajectory tracking control law based on the state observer is compared with the ordinary backstepping control law by simulation experiment,It is obviously that the trajectory tracking control method based on the extended state observer can effectively reduce and eliminate the influence of disturbance on its control system,and the tracking accuracy of the reference trajectory of the wheeled mobile robot is ensured.Thus,it is verified that the designed control law is effective to the disturbance exists in the mobile robot control system.