Research On Integrated Wheel Module Of Multi-system And Steer-by-wire Technology

In recent years,with the rapid development of vehicle electrification and intelligent technology,much more innovative technologies used in automobile.The integrated wheel module of multi-system will be a new configuration of automobile technology in the future,which integrates structural and technological innovation.It realizes the functions of driving,steering and braking through the hub motor,steer-by-wire system and braking system integrated in the wheel module.After special design,vehicles with the integrated wheel module of multisystem can realize four-wheel steering,in-situ center steering,lateral driving and other steering modes,which provides an effective way to solve the problem of traffic congestion and improve the driving safety under extreme conditions.This paper focuses on the structure of the integrated wheel module of multi-system,bottom control strategy of steer-by-wire motor and top control strategy of steer-by-wire system.The main contents of this paper are as follows:(1)Two structural schemes of the integrated wheel module of multi-system are designed,and suspension parameters,wheel alignment parameters are set according to the functional requirements and structural characteristics of wheel module.Based on ADAMS/Car,the kinematics analysis of the structure of the innovative double wishbone suspension is carried out to verify its rationality.Aiming at the problems exposed in the simulation experiment of two wheels parallel runout,the suspension parameters are optimized by ADAMS/Insight,which provides a theoretical basis for the production of the integrated wheel module of multi-system.(2)The bottom control strategy of steer-by-wire motor of the integrated wheel module is designed.According to the load torque of the steering motor,its type and performance parameters are selected.The mathematical model of permanent magnet synchronous motor(PMSM)is established in synchronous rotating coordinate system,and the three-closed-loop control system of PMSM is established based on SVPWM and vector control technology.Simulation results show that active disturbance rejection control(ADRC)can improve the speed of position following response of PMSM and effectively reduce the influence of variable load disturbance.(3)The top-level control strategy of steer-by-wire system of the integrated wheel module of multi-system is designed.The expected values of yaw rate and lateral acceleration under ideal driving state are determined by two degrees of freedom vehicle model.Based on Fuzzy Adaptive PID algorithm,a comprehensive feedback control strategy is built to realize the front wheel active steering control.In Simulink-Car Sim,the effectiveness of the bottom algorithm of steer-by-wire motor and the front wheel active steering control is verified,and the bottom algorithm of steer-by-wire motor in this paper is extended to other vehicles,which makes theoretical verification for the future application of the integrated wheel module of multisystem in all levels of vehicles.(4)According to the content of the previous study,the real vehicle test is carried out.Four sets of the integrated wheel modules of multi-system are produced and assembled in the test vehicle.After the assembly,the vehicle controller and CAN communication network are designed and built.The test vehicle is debugged to the normal state,and the angle following performance of the steer-by-wire motor and the front wheel active steering control strategy designed in Chapter 4 are verified respectively.The test results show that the steering motor can follow the steering wheel angle well,and the active steering control can improve the handling stability of the vehicle when it is steering.