Research On The Coordinated Control Strategy Of Vehicle Under The Condition Of Tire Blow-out

Tire blow-out greatly affects the stability of cars.In order to prevent the vehicle from yawing after blow-out,a coordinated control algorithm is designed to control the stability and trajectory of the vehicle.At present,researches only focus on the single control of the tire blow-out of vehicle,which is difficult to ensure the stability control and improve the trajectory tracking ability of the vehicle.Therefore,based on the stability control,this paper proposes a set of coordinated control schemes for the vehicle in the process of tire blow-out,coordinated control for the brake and steering of the vehicle,so as to guarantee the stability and improve the trajectory tracking ability when the vehicle is in the process of tire blow-out The main contents of this paper are as follows:1)Based on the vehicle dynamics software Car Sim,the whole vehicle model,driving condition and road environment model are designed to simulate the vehicle.2)The tire model of Simulink is built based on the tire theory of Unitire,and the simulation platform for tire blowout experiment was established jointly with the vehicle dynamics software Carsim.By the establishment eight degree of freedom vehicle model,the simulation platform for tire blowout experiment was verified under the condition of two shifting lines and serpentine,It is concluded that the front tire blowout is more dangerous than the rear tire blowout.3)The ideal two degree of freedom model of the vehicle is established,the control method of differential braking is adopted,and the stability control system of the vehicle is designed by using the fuzzy sliding mode control algorithm.The yaw moment is distributed to each wheel according to the braking force distribution strategy.Through the design of different tire blow-out conditions for control simulation experiments,the correctness of the stability control method based on differential braking is proved.4)The method of active steering is used to control the trajectory of the tire blow-out vehicle.The algorithm of variable universe fuzzy PID is used to control the trajectory of the vehicle with tire blow-out.According to the comparison between the actual trajectory and the targeted trajectory of the blow-out vehicle,the scope of the fuzzy universe is adjusted continuously,so as to adjust the PID parameters,so as to reduce the trajectory error of the vehicle with a tire blow-out.5)A coordinated control strategy is designed,which combines the differential braking control method with the active steering control method.The weight of the differential braking and active steering is adjusted according to the magnitude of the sideslip angle and the longitudinal velocity of the mass center.Through the tire blow-out experiment on the car,the conclusion that the coordinated control is better than the stability control by the differential braking method is obtained.The innovation points in this paper:1)The characteristic parameters of vehicle stability are analyzed.By controlling the sideslip angle and yaw rate of the vehicle to maintain the vehicle's stabilization,and designed the fuzzy sliding mode control algorithm.The yaw moment is effectively compensated by the fuzzy control principle,which improves the robustness of the stability control system.2)The active steering control system is designed by variable universe fuzzy PID,and the coordinated control system is designed by combining with the stability control system.According to the driving state of the vehicle,the weight coefficients of the two are distributed,so that the coordinated control system can effectively control the stability and track tracking ability of the vehicle in the process of tire blow-out.