Research On Trajectory Tracking Of Autonomous Four-Wheel Steering Electric Vehicle

Compared with traditional front-wheel-steering cars,autonomous four-wheel-steering electric vehicles can rely on their own flexibility to track target trajectories through reasonable control and have good trajectory tracking capabilities.The dissertation focuses on the trajectory tracking and control capabilities of autonomous four-wheel-steering electric vehicles,which are independently developed by the research group.The thesis mainly researches from the following aspects:First,according to the actual parameters of the autonomous distributed driving electric experimental platform vehicle.Establish simulation models for autonomous four-wheel steering electric vehicles: car body model,power system model,suspension system model,tire system model,braking system model,and steering system model.Select typical operating conditions to verify the rationality of the simulation model.Secondly,the longitudinal and lateral control of the vehicle is studied.The longitudinal control adopts the speed control;the lateral control studies the lateral displacement control strategy and the lateral composite control strategy respectively;through the selection of typical working conditions for experimental verification,it is concluded that the lateral composite control strategy has more advantages.Furthermore,four-wheel steering control is studied.The feed forward control strategy,the feedback control strategy and the four-wheel steering control strategy based on fuzzy control theory are studied separately.The experimental verification shows that the four-wheel steering control strategy based on the fuzzy control theory is more conducive to improving the vehicle's Driving stability.Finally,the vehicle control strategy is performed for simulation verification and real vehicle verification.The simulation verification mainly verifies the trajectory tracking ability and the ability to resist the sudden change of the trajectory;the real vehicle verification uses an autonomous distributed driving electric experimental platform vehicle to verify the trajectory tracking ability.The research results show that the trajectory tracking control strategy studied in this paper can make autonomous four-wheel-steering electric vehicles have good trajectory tracking ability,and have a certain ability to resist the sudden change of trajectory.