Electric Vehicle Hub Motor Viboration And Suspenion Matching

In recent years,the climatic environment has been deteriorating and global temperatures have continued to rise,so the field of BEV(Blade Electric Vehicles)is booming.Compared with traditional fuel vehicles,BEV has many unparalleled advantages,so the market is very broad.At present,BEV can be divided into two main driving forms: centralized motor drive form and hub motor drive form.Among them,the centralized motor drive form retains most traditional fuel vehicles’ structures.The hub motor drive form directly integrates the power,brake and transmission structure into the automobile hub,which greatly simplifies the mechanical structure of the car.Then,it brings the advantages of high transmission efficiency,simple structure and high space utilization.But its structure also brings a lot of car dynamics problems.This structure will deteriorate the vehicle ride comfort,increase vehicle vibration,and deteriorate the suspension filter performance.In this paper,the advantages and disadvantages of hub motors and the problems arising from their deployment in pure electric vehicles are introduced,that is,the addition of hub motors leads to the increase of unsprung mass,and the motors will also produce electromagnetic vibration,which further worsens ride comfort and handling stability.Therefore,it is necessary to adopt various means of structure and control to optimize the vibration results.Through suspension system of the wheel hub motor drive form,the modeling and simulation proved the unsprung quality to increase the impact on the riding comfort and handling stability,the establishment of permanent magnet synchronous motor model makes the suspension system more in line with the actual situation,then completed a suspension type optimization and the research of control methods of the magnetorheological suspension,the suspension parameters to the performance evaluation of the root mean square value greatly decreases,and the desired optimization goal.In view of the above problems,the purpose of this paper is to reduce the vehicle vibration and design the controller to optimize the suspension.The specific work contents are as follows:(1)Established quarter suspension models in the form of a conventional form and hub motor form.Then,the simulation of Matlab/Simulink proves that the increase in the unsprung mass of the hub motor form does deteriorate the ride comfort and steering stability of the car.(2)The motor model was established by Maxwell electromagnetic simulation software.The finite element analysis of the radial magnetic field of the motor was used to obtain the radial magnetic field force of the motor under static eccentricity and dynamic eccentricity.Applying the obtained radial magnetic field force to the Matlab/Simulink model of the hub motor makes the model more realistic.(3)The dynamic vibration absorber is used to optimize the suspension,and a magnetorheological damper is added between the body and the wheel to make it a semi-active suspension.For the control of semi-active suspension,the mature ceiling damping control is first adopted as the comparison standard,and then the fuzzy control method is used to optimize the suspension control.The rules and fitness of fuzzy control are obtained by genetic algorithm.Finally,establish the 11-degree-of-freedom vehicle model to verify the simulation results.