Study On The Front Wheel Shimmy And Active Control Technology Of Independent Suspension Electric Vehicle

Because of air pollution and oil security,auto companies,auto parts suppliers,universities and institutes have invested heavily in developing electric vehicles.As a classic problem of vehicle dynamics,the wheel shimmy appears in electric vehicles,which needs to be studied separately.In the past,the wheel shimmy of dependent suspension vehicle was mainly studied.Without adding new parts,researchers want to eliminate the wheel shimmy by optimizing vehicle parameters.Due to the interference of multiple factors that affect wheel shimmy,researchers can’t eliminate the wheel shimmy completely.Based on the previous achievements,this paper uses active control technology to eliminate the wheel shimmy of independent suspension electric vehicle.When the electric vehicle is disturbed,the simulation shows that the active control device can effectively suppress the wheel shimmy of electric vehicle,and the system has good robustness.The specific contents of this paper are as follows:(1)For the electric vehicle that is driven by in-wheel motor with independent suspension and integral steering,the dynamic model with active control module of wheel shimmy is been established.According to the dynamic model,the differential equation of wheel shimmy is presented with the help of Lagrange equation of the second kind.(2)Based on the dynamic model of wheel shimmy,the active control system of wheel shimmy is set up with the help of the state feedback control law that belongs to the modern control theory.(3)Firstly,the dynamic model and the closed-loop control system of wheel shimmy are simulated with the help of Matlab.At different speeds,the simulation shows that the state feedback control system has a shorter convergence time than others,and the system has good robustness.Secondly,through the combined simulation of Car Sim and Simulink,the accuracy of dynamic model and the effectiveness of active control system are proved again.