A Study Of Stability Control Under The Drive Motor Failure Of Distributed Drive Electric Automobile

Four-wheel distributed drive electric vehicle is the most potential and advantage of pure electric vehicles,the application prospect is very wide.How to ensure the handling stability of the vehicle under the fault of the drive motor has become one of the important issues restricting the development of four-wheeled distributed drive electric vehicles,and has gradually turns into a trending topic of academia.In order to solve the problem of control stability control under drive motor fault,the stability envelope boundary and stability control strategy under the four-wheel distributed drive vehicle drive motor fault has been studied in this paper,key research includes:First of all,by analyzing the force condition of the components of the four-wheel distributed drive vehicle,the dynamic model of the whole vehicle plane motion,tires,drive motor and other modules is integrated in Matlab/Simulink,so the construction of the 7-dof dynamic vehicle model is completed.After that,by comparing to the motion state parameter response of the integrated model in Car Sim under the same driving conditions,the model-accuracy is confirmed,the theoretical tool is established for the following phase plane analysis.Secondly,the manipulating stability of the four-wheel distributed drive vehicle under the fault of the drive motor is analyzed.According to the characteristics of being able to apply different additional yaw moment to the vehicle through torque distribution,a phase plane stability envelope boundary computing method suitable for distributed drive electric vehicles is proposed.At the same time,the influence of multiple external factors to phase plane stabilization boundary are also analyzed which is focusing on the analyzing of the stable boundary after the performance degradation due to the failure of the drive motor and the mapping relationship between the stable boundary parameters and the failure coefficient of the drive motor is established.So that the problem of the existing research methods for stability envelope boundary analyzing are invalid under the drive motor failing can be solved and the stability constrains of the state parameters are provided for the stability control system.This enables the distributed drive vehicle to more fully exert the stability control ability in the case of motor failure.Finally,the distributed drive vehicle stability layer controller is designed,in which the upper controller is the speed follow control based on PID control and the additional swing torque control based on the obstacle Lyapunov function(BLF),while the lower controller is the driving torque optimization distribution based on the secondary planning algorithm.Through the joint simulation of Matlab/Simulink and Car Sim,the result turns out that the stability control system designed can improve the handling stability,power and response speed of the vehicle in the event of drive motor failure.