Research On Magnetorheological Valve Controlled Vibration Damping Technology Of Automobile Seats

Vehicles,especially commercial vehicles and engineering vehicles often travel in complex road conditions and harsh road conditions such as construction sites,which will cause passengers,especially drivers,to be in a harsh vibration environment with low frequency and large amplitude for a long time.As the last link of the vibration path from the road surface excitation to the driver,the vibration reduction performance of the seat suspension is very important,which directly affects the comfort and safety of the driver.As a semi-active intelligent device,the magnetorheological damper can effectively improve the vibration of the seat,but the disadvantages of high cost and large mass limit its application.Aiming at the performance design requirements of the current car seat suspension shock absorber and the current design drawbacks of the magnetorheological shock absorber,a magnetorheological valve-controlled shock absorber is proposed and applied to the semi-active seat suspension system to improve the Ride comfort of car seats.Through the analysis of the working principle,theoretical modeling,magnetic field simulation,parameter optimization,device performance test and system simulation analysis of the magnetorheological valve-controlled shock absorber,the correctness of the design idea of the magnetorheological valve-controlled shock absorber is verified,and the vibration reduction effect of the shock absorber in the seat suspension is also verified.This work consists of the following aspects:(1)The working principle and mechanical model of the magnetorheological valve-controlled shock absorber are established.According to the design requirements(installation requirements and damping output requirements)of the seat suspension shock absorber,the structural scheme of the magnetorheological valve-controlled shock absorber is determined,including the structural scheme of the magnetorheological valve piston assembly.The damping output mechanical model of the valve-controlled shock absorber is derived,and the validity and correctness of the magnetic circuit design are analyzed through the magnetic field simulation.(2)Parameter optimization of magnetorheological valve-controlled shock absorbers.Optimize the key parameters of the magnetorheological valve piston assembly according to the seat vibration reduction requirements and the determined structural scheme.First select the magnetorheological fluid material and test its performance data,select the return spring according to the need of zero field output and conduct stiffness test.Then combined with the boundary conditions of the parameters of the structural design and the design requirements of the optimization objective,the key structural parameters are optimized by using the multi-objective optimization software.Finalize the size parameters,determine the drawings and process according to the plan.(3)Performance Test and Analysis of Magneto-Rheological Valve Controlled Shock Absorber.In order to prove the correctness and effectiveness of the design principle of the magnetorheological valve-controlled shock absorber proposed in this paper,in this chapter,according to the previous theoretical calculation,optimization analysis results,test conditions and assembly conditions,a set of magneto-rheological valve-controlled damper prototypes were processed and assembled.The variable damping mechanical properties of the prototype were tested and analyzed using the MTS test device,and the variation law of the damping output following variable current and variable excitation(amplitude,frequency)was studied.(4)Simulation analysis of vibration isolation of magnetorheological semi-active seat suspension.In order to verify the damping effect of the magnetorheological valve-controlled shock absorber in the suspension of the car seat,a mechanical model of the damping force of the magnetorheological valve-controlled shock absorber with respect to current and speed was established.Obtain the signal input of the random road surface,and obtain the input excitation of the seat suspension bottom plate according to the vibration transmission path of the vehicle.Finally,through the multi-body dynamics co-simulation of MATLAB and Adams,the vibration isolation effect of the magnetorheological semi-active suspension in the sky-hook control is analyzed,and the effectiveness of the magnetorheological valve-controlled shock absorber is verified.