Research On Robust H_? Control Of Trajectory Tracking Of Wheeled Mobile Robot

As mobile robot has broad application prospects in deep space exploration,safety and rescue,mining,agriculture,forestry,logistics and military fields,it has become a hot research field at home and abroad in recent years,And has made some research results.In the theoretical research of trajectory tracking of mobile robots,it is usually assumed that there is only pure rolling without lateral and longitudinal sliding movements between the wheels and the ground.This ideal assumption makes the wheeled mobile robot a typical multiple input multiple output nonholonomic constraint Dynamic systems,often referred to as nonholonomic wheeled mobile robots.If only considering the control performance of the deterministic model,this control law will be greatly limited in practical engineering applications,and will not be able to cope with external disturbances and changes in internal parameters.This is also the biggest challenge for robot trajectory control.In this paper,a robust H_? controller based on a linear variable parameter model is proposed for the dynamic uncertainties in the nonholonomic mobile robot model.At the same time,a pole-tracking trajectory controller is proposed.The Euler-Lagrange method was used to establish the dynamic equation of robot trajectory tracking.The dynamic model was transformed into a linear variable parameter model with convex polyhedral structure by using the variable gain linear variable parameter convex decomposition technique.According to the robust control theory and linearity Matrix inequality theory,a state feedback controller is designed at each vertex of the convex polyhedron,and then a linear variable parameter controller is synthesized by using each vertex controller.Simulation results show that the robot has good tracking performance for the change of parameters.The main work of this paper is to establish the mathematical model of nonholonomic mobile robot firstly.Secondly,convex polytope is used to determine the convex polyhedron model and each vertex of the robot according to the actual movement of the robot.At the vertex,the linear matrix Inequality(LMI)method is used to design the state feedback H_? controller.Convex optimization techniques can be easily solved.Finally,Based on the H_? controller of each vertex,the global controller of the mobile robot is obtained by using Linear Parameter-Varying(LPV)method.Finally,the simulation results of MATLAB show that this control method has good tracking performance for a given trajectory in the presence of parameter uncertainty and external disturbances.