Study On Simulation Of Vehicle Semi-active Suspension Under Road Surface Exitation

Suspension fork is an important part of the vehicle.It has a great effect on Various performance about Vehicle running smoothness and the stability of the control.Now, The vehicle is widely used passive suspension which is made up of elastic element and shock absorber. Passive suspension is difficult to improve the smoothness and stability of the vehicle at the same time when the vehicle is running on the uneven road at a high speed .In order to overcome the restrictions of the passive suspension on improving vehicle performance. Semi-active suspension is a new avenue to improve the vehicle performance.According to road conditions and the vehicle actual running situation.Semi-active suspension can optimize the control to achieve better overall performance.This subject studies on the semi-active suspension and builds a dynamic model of semi-active suspension by a quarter of the vehicle and two degrees of freedom. Then the controller of the suspension has been designed.This subject overviews there indicators of the vehicle performance. Namely, the vertical body acceleration, suspension deflection and the wheel of East dynamic load.Semi-active suspension has much more control strategies . Selecting the BP network of the artificial neural network in this subject. Especially it is suitable for nonlinear control. The simulation model of passive suspension and semi-active suspension is built by MATLAB7.0/Simulink.This subject simulate the input signal of white noise road. The simulation results show that semi-active suspension controled by BP network improved vehicle ride comfort and operation stability ,its performance is better than passive suspension.This subject can be used as the experimental research of semi-active suspension ,provides theory and numerical reference and provides the theoretical basis for semi-active suspension application in the vehicle.