Research On Motion Control Method Of Mobile Robot Based On Uncertainty Analysis In Complex Environment

Wheeled Mobile Robot(WMR)has been widely used in various fields due to its high flexibility.With the more complex application scenarios,wheeled mobile robots will receive many uncertainties.These uncertain factors will bring unstable factors to its motion control system.Therefore,it is necessary to study the motion control of mobile robots based on uncertainty analysis in complex environments.The main contents of this paper are as follows:The first is to study the problem of mathematical model establishment considering the uncertainty of the wheeled mobile robot itself.The velocity of the mass center and the geometric center are not coincident,and the kinematics model is established.The relationship between the torsion angle of the universal wheel and its physical parameters is analyzed,and the dynamic modeling of the universal wheel and the body of the wheeled mobile robot is carried out by means of Newtonian vector mechanics.Aiming at the longitudinal slip phenomenon in complex environment,the slip parameters are introduced to analyze the motion model of the wheeled mobile robot under the condition of longitudinal slip.Secondly,considering that the wheeled mobile robot is in an ideal condition,that is,when the wheels do not slip,the influence of its own uncertainty on the control system is analyzed,and a WMR dynamic torque controller based on uncertainty analysis is designed.The back-stepping method is used to design the kinematic control law to ensure the convergence of the pose error;the dynamic torque controller is designed using the integral sliding mode idea,and the disturbance observer is used to detect the disturbance caused by the torsion of the universal wheel.Observations are made and compensated into the control system.The simulation results show that the uncertainty disturbance caused by the torsion angle of the universal wheel will affect the stability of the dynamic torque controller.Thirdly,in view of the problem of longitudinal slippage of WMR during motion in complex environment,a WMR trajectory tracking control method based on trigger control is proposed.Two unknown slip parameters are estimated by an adaptive method.Based on the idea of trigger control,the trigger function is designed to avoid the highfrequency update of the control system in complex dynamic control operations and waste of computing resources.The stability of the system is proved by Lyapunov stability theory,and Zeno analysis of trigger control is carried out.The simulation results demonstrate the effectiveness of the control system.Finally,the WMR experimental platform is built to verify the control system designed in this paper.The experimental results show that the root mean square value of the maximum position error of the control system is reduced by 37.37%when considering the disturbance of the universal wheel.When the complex environment increases the root mean square value of the maximum position error of WMR by 56.85%,the designed control system can still make the position error converge in a short time.