Research On Lateral Control Of Intelligent Pure Electric Vehicles Based On EPS

The rapid popularization of cars has promoted social and economic development and improved human life.But at the same time,Traffic congestion caused by the rapid popularization of vehicles,environmental pollution,frequent traffic accidents and other hazards are increasingly serious.To achieve intelligent vehicles can be a good solution to these problems.Lateral control is one of the key technologies of intelligent vehicles,mainly to study how to control the steering to achieve intelligent vehicle lateral tracking of the target trajectory.In this paper,intelligent vehicle lateral control has been studied,the main contents are as follows.First of all,the structure and working principle of the intelligent vehicle lateral control system are analyzed and studied.In order to realize the autonomous steering function,a control strategy of the intelligent driving lateral control system is designed.In view of the potential conflict of human-machine interaction in the active steering control,a driver operation decision module is constructed.Then,the dynamic model of the automobile and the tire model are studied,the reason of the parameter perturbation of the model is analyzed,and the stability and adaptability of the controller are put forward.Based on the assumption of steady-state circular motion,the ideal value of yaw rate under this assumption is derived according to the optimal preview theory.Aiming at the nonlinearity and parameter uncertainty of the steering system,a robust control method based on sliding mode variable structure is adopted,and the value of yaw rate of the ideal value is taken as a reference to design the upper tracking trajectory controller.In order to reduce the chattering of the sliding mode controller,a fuzzy controller with gain adjustment is designed.According to the requirement of lateral control,based on the incremental PID control method,the EPS control and model derivation are designed and the controller of the underlying actuator in active steering mode is designed.Thirdly,a joint simulation platform is set up in MATLAB/Simulink and Carsim environment,and the lateral control system of the system is simulated under different operating conditions to verify the effectiveness of each module of the lateral control system.Finally,based on the unmanned formula racing vehicle experimental platform,the executive controller is debugged and tested to verify the effectiveness of the controller.The actual vehicle test program of transverse path tracking is designed and the steering accuracy test is carried out on the active steering system of SUV intelligent experimental vehicle.The test shows that the steering control accuracy is good.By collecting the road data through the positioning system,the offline map is established to verify the designed transverse controller.The experimental results show the effectiveness of the designed transverse control system.