Research On Control Method Of Vehicle Semi-active Suapension Under Discrete Impact Road Conditions

When the vehicle is running under the condition of discrete impact road surface,the severe impact will bring discomfort to the passenger and affect the ride comfort.Based on this condition,this paper takes the magnetorheological semi-active suspension as the actuator.This paper considers the pre-exploration of discrete impact roads,and introduces the semi-active suspension controller by introducing the preview information to suppress the vertical and pitch and roll motions caused by the discrete impact road surface.In addition,the software and hardware design of the semi-active suspension system is also carried out.In this paper,the characteristics of discrete impact road surface excitation signals are analyzed,and the general mathematical description of discrete impact road surface is determined.In this paper,the relationship between suspension damping and response characteristics is explored by simulating under different suspension damping.In this paper,the dynamic model of the magnetorheological semi-active suspension is established.A seven-degree-of-freedom vehicle model with magnetorheological semi-active suspension that can reflect the pitch and roll characteristics is also established.Furthermore,compared with the vehicle dynamics simulation software,it is verified that the established model can correctly reflect the response characteristics under discrete impact road conditions.Discrete impact pavement has the characteristics of short action time and high excitation frequency.However,the existing semi-active suspension control mostly adopts a single control parameter,and the control effect is not ideal under the working condition.This paper proposes to introduce road surface preview information to improve the control effect.For vehicles with environmental sensors such as lidar,it is generally assumed that the road surface preview information can be directly obtained.For vehicles without environmental sensors,this paper considers the road surface recognition based on the front wheel dynamic information,and designs the road surface contour estimator with extended Kalman filter.The discrete impact road information acquired by the front wheel can be provided to the rear wheel suspension system based on the concept of wheelbase prediction.Under the premise that the discrete impact road information can be previewed,this paper designs an optimal controller with preview.The simulation results show that the introduction of the preview information can effectively suppress the vertical,pitch and roll motions caused by the discrete impact road surface and improve the ride comfort.Finally,this paper designs the software and hardware system for thesemi-active suspension vehicle test.The design includes the top-level framework of the hardware and software and the hardware and software design of the controller.Finally,the availability of the controller is verified by the module test.