Study On Control Algorithm For Compensating Time Delay Of Magneto-rheological Semi-active Seat Suspension

The vibration caused by the uneven road during the driving of the vehicle will affect the driver’s operating stability and riding comfort,and the long time to be exposed to vibration environment will cause health problems and safety hazards.The seat suspension is a force-transmitting component connecting the vehicle cab and the human body,so it can block the transmission of vibration to the driver’s body.Commonly used seat suspensions include passive seat suspension,active seat suspension and semi-active seat suspension.This paper mainly focuses on the semi-active seat suspension whose actuator is a magnetorheological damper(MRD).The time delay of the magnetorheological damper will affect the semi-active real-time control,so the main research content of this paper is to get the time delay of the damper,and analyze the impact of the damper time delay on the vibration isolation of the semi-active seat suspension.Two semi-active control algorithms are designed to compensate the time delay of the damper and improve the vibration isolation performance of the seat suspension.The research work carried out is as follows.(1)To establish the seat suspension model,firstly,construct pseudo-random excitation,and then establish the positive model and inverse model of the magnetorheological damper;secondly,establish the dynamic model of the air spring;then through the established damper model,the air spring model and the human body concentrated mass to build the seat suspension model;finally,through sinusoidal excitation,the simulation results of the built seat model in Simulink and the results of the actual seat suspension in the experiment were compared to verify the accuracy of the built seat model.(2)Determine the response time of the damper.The response time mainly includes the time from the voltage control signal to the generation of damping force of the magnetorheological damper.The response time of the magnetorheological damper is obtained through experiments.The obtained response time of MRD is used to simulate and compare the effects of skyhook control with time delay and skyhook control without time delay on the vibration isolation of the seat suspension.(3)Two semi-active control algorithms are designed to compensate for the time delay of the damper.In this paper,a grey prediction skyhook algorithm and a sliding mode variable structure control algorithm are designed to decrease the impact of the damper delay on the vibration isolation of the semi-active seat suspension.The principle of the gray prediction skyhook control algorithm and the sliding mode variable structure control algorithm are introduced.According to the algorithm principle and the research object,the corresponding semi-active control algorithms are designed,and finally the simulation verification is completed according to the two kinds of control.(4)Build a seat suspension vibration test platform to test the vibration of the seat suspension under different control conditions and evaluate its ride comfort and driving stability.Verify effectiveness that the gray prediction skyhook algorithm and the sliding mode variable structure control algorithm are used to compensate time delay of dampers and improve the vibration isolation effect of the seat suspension.