Study On Multi-field Coupled Vibration Of In-wheel Motor Electric Vehicle

The hub motor-driven vehicle has a simple overall layout,high transmission efficiency,strong controllability,and easy implementation of integrated chassis control.However,the introduction of hub motors will bring the following vertical negative effects:1)Increased unsprung mass;2)Electromagnetic coupling disturbance force induced by uneven air gap of the motor.These vertical negative effects will deteriorate ride comfort and handling stability of vehicles and hinder its further development.How to effectively reduce the vertical negative effect caused by the application of the hub motor has become one of the key issues in the research and development of the hub motor drive vehicle.To solve the above problems,this paper proposes a model of a hub motor-suspension system with a dynamic vibration absorbing structure.A set of spring-damping structure separates the motor from the wheel to reduce system vibration under complex driving conditions.It also can absorb vibration energy and reduces the influence of electromagnetic disturbance force on vehicle ride comfort and handling stability.This article focuses on the dynamic vibration absorption structure and mainly does the following work:(1)In this paper,the analytical method is used to model the switched reluctance motor and the torque model and the disturbance force model of the motor are obtained.the longitudinal and vertical coupling models of the vehicle were established.The influence of unsprung mass increase and motor disturbance force on vehicle is also discussed.At the same time,the dynamic response of the hub motor-suspension type with a dynamic vibration absorption and a traditional hub motor suspension type is compare.(2)Multi-body model of a new in-wheel motor-spension structure was built in LMS.-motion.Compare the co-simulation model with the single mathematical model to verify the realizability of the new hub motor-suspension structure.According to the results of the co-simulation,the parameters of the components of the suspension structure are designed(3)Check the strength of components of the new in-wheel motor-suspension structure,In addition,The topological optimization of parts with more material redundancy in the parts is carried out to reduce the unsprung mass and improve the ride comfort and handling stability.(4)Combining the two semi-active shock absorbers,a new type of wheel hub motorsemi-active suspension structure was proposed.The control strategy was designed.The Pareto optimal set was used to compare the passive and semi-active suspensions and optimize the damping parameters.