Research On Coordinated Control Strategy Of Electric Vehicle Chassis Stability

As the most important part of electric vehicle,the active safety system of chassis directly affects the safety performance of the whole vehicle.The lateral stability system(ESP)of the chassis,the longitudinal stability system(ABS)and the driving anti-skid system(TCS)are the components of the chassis stability system,which play an important role in the vehicle stability.In order to meet the good performance of vehicles under different driving conditions,the integration of ABS,TCS and ESP is the development trend of vehicles in the future.When the vehicle is driving under complex conditions,due to the mutual coupling between the systems,the simultaneous operation of the three systems will affect the performance of the system.Therefore,through the reasonable coordinated control can solve among the three,the longitudinal braking stability can be solved,and improved the handling stability of the vehicle at the same time.In this thesis,taking the chassis system of electric vehicle as the research object,the coordinated control of the lateral stability system and the longitudinal braking stability system is studied in the following aspectsFirstly,stated the development of electric vehicle from home and abroad,introduced the working principle of vehicle chassis subsystem and the status of subsystem at home and abroad,and also stated chassis coordinated control at home and abroad.Secondly,taking the electric vehicle as the research object,based on the parametric modeling method,the vehicle model is established by using Car Sim software,and the model simulation is verified by the national standard test.Then,selected the model-free adaptive control algorithm to the chassis lateral stability system ESP,the reasons of vehicle instability are analyzed,and the yaw rate and mass center sideslip angle are determined as control variables.The theoretical calculation formula of control variables is derived through the vehicle 2DOF model,and the logic threshold control algorithm is used to control the ABS and TCS systems of the longitudinal braking stability system.The control algorithm model of each system is built by using Simulink.At last,under braking and driving conditions,through the cosimulation of Simulink/Car Sim,the respective algorithms are simulated and verified,which proves the effectiveness of the respective control algorithms.Finally,the judgment method of vehicle stability is analyzed,and the calculation formula of coordinated yaw moment is derived,and the coordinated control strategy of ABS,TCS and ESP is formulated.The simulation results show that the proposed coordinated controller can maintain the vehicle handling and stability performance under complex working conditions.