Research On Mcpherson Supension Angle Vibration Model And Its Lqg Control

In this paper,the vibration model between the traditional body and the wheel used to study vehicle ride comfort is improved.For the control of the MacPherson suspension system,based on the angular coordinate system,the angle of the suspension control arm is expressed as the unsprung Quality of movement.In the new model of a two-degree-of-freedom quarter-vehicle suspension,the suspension state output is the vertical acceleration of the sprung mass and the angular displacement of the control arm.The results show that the traditional two-degree-of-freedom vibration model of the body and the wheel is a special form of the new model,and the horizontal motion of the spring body is considered in comparison with the traditional model,which is more in line with the real motion of the MacPherson suspension system.Based on the new model of a quarter-vehicle suspension with two degrees of freedom,we further design a new model of a four-degree-of-freedom vehicle suspension.The suspension state output is the vertical acceleration of the sprung mass.The vehicle's pitch angle acceleration and the angular displacement of the left and right control arms.The results show that there are excellent performance evaluation indicators between the traditional model and the new model,but the gap is not large.However,compared with the traditional model,the new model considers the horizontal motion of the spring body,which is more in line with the real motion of the MacPherson suspension system.Based on the design of the two-degree-of-freedom quarter-vehicle suspension new model and the four-degree-of-freedom two-vehicle suspension new model,we further linearly optimally control the active suspension of the two models.Design,In the Matlab/Simulink environment,the vibration analysis of the vehicle under different working conditions is given,and the two are separated from the traditional two-degree-of-freedom quarter-vehicle suspension model and the traditional four-degree-of-freedom one-half vehicle.The suspension model was compared and analyzed under the same conditions.The results show that the performance of the active suspension model is better than that of the passive suspension model,both for the new model and the old model.Therefore,the LQG controller designed for the old and new models has excellent control effects.However,the LQG controller designed has different optimization results between the performance indicators of the old and new models,and each has its own advantages and disadvantages.The new model is more in line with the real motion of the MacPherson suspension system,which is more practical for guiding the design of the whole vehicle.