The Study On Fault Diagnosis And Tolerant Control Strategy Of Vehicle Control System For Pure Electric Bus

In recent years,affected by the national policy of new energy industry,the pure electric vehicle industry is booming,the vehicle control strategy is more reasonable and precise,and the electric vehicle is becoming more and more perfect.That requirements of control unit,actuator and the sensor performance is more stable,to ensure the reliability and safety of the vehicle.In the same hardware conditions,launching vehicle fault diagnosis and fault-tolerant control to ensure the safety in the vehicle driving,which has become a key problem in current research.This topic comes from Jilin University and Jilin Province high and new electric vehicle co.,LTD.signed a technology development contract “Research on vehicle control strategy and development of control system test platform for pure electric vehicle”.In this project,based on the previous work in the company,Jilin University is mainly responsible for completing vehicle control strategy,fault diagnosis and fault-tolerant control strategy,to ensure the reliability and safety of vehicles in the practical use.The main contents of this paper are as follows:1.Selecting the motor,battery pack and accelerator pedal as the fault diagnosis object,completes fault mechanism analysis,and the analysis of influence of vehicle failure may be caused.Selecting the accelerator pedal sensor signal fault,motor overload and battery pack SOC correction as the research object.According to the actual demand,completing the matching design of the cooling system of the motor.Selecting the circumferential water-cooling structure as the cooling water jacket;calculating the motor's loss of rated power and peak power,and completing the analysis of motor cooling.2.Fault diagnosis based on the failure analysis,aiming at the accelerator pedal sensor signal fault,proposing fault diagnosis method based on logic gate limit,and tolerant control method based on fault law reconfiguration.The motor overload fault control strategy is based on the torque adjustment coefficient to limit torque of motot.Proposing the battery pack SOC correction control strategy based on the cycle times,temperature and discharge rate.3.Using the MATLAB/Simulink to build the related control strategy model and to simulate the strategy model.The simulation results show the control strategy can achieve fault diagnosis very well,and can come true the fault signal tolerance control.4.Using the vehicle control strategy hardware in loop test platform to verify the fault diagnosis and fault-tolerant control strategy of accelerator pedal signal.The results show the fault diagnosis strategy can achieve diagnosis very well,as well the fault-tolerant control strategy.5.Completing vehicle test of SOC correction control strategy.The results show in the range of the allowable error,the SOC correction control strategy can fulfill battery pack SOC correction.