Experimental Study of a Variable Stiffness Seat Suspension Installed With a Compact Rotary MR Damper

Shuaishuai Sun,Weihua Li,Penghui Wang,Jian Yang,Masami Nakano,Longjiang Shen,Shiwu Zhang

doi:10.3389/fmats.2021.594843

Abstract

Traditional MR seat suspension without stiffness control is not able to avoid the resonance between the excitation and the seat, though it can dampen the vibration energy. To solve this problem, this paper proposed a variable stiffness (VS) magnetorheological (MR) damper to implement an advanced seat suspension. Its natural frequency can be shifted away from the excitation frequency through the variations of stiffness, thereby realizing the non-resonance control. The new seat suspension is designed and prototyped first, and then its dynamic property under different energizing current, excitation amplitude, and excitation frequency was tested using an MTS machine. The testing results verified its stiffness controllability. The vibration attenuation performance of the seat suspension was also evaluated on a vibration shaking table. The vibration reduction performance of the seat suspension was evaluated under two kinds of excitations, i.e., harmonic excitation and random excitation; the experimental results indicate that the new seat suspension outperforms passive seat suspensions regarding their ride comfort.

Highlights

Vibration transferred from uneven road surfaces, vibrating tools, and vibrating machinery to a vehicle driver’s body significantly reduces the driver’s comfort
Two accelerometers were used to measure the accelerations of the excitation and the seat suspension, respectively
Considering that an appropriate controller is critically important for the suspension system to achieve good performance, a controller based on the short-time

Summary

INTRODUCTION

Vibration transferred from uneven road surfaces, vibrating tools, and vibrating machinery to a vehicle driver’s body significantly reduces the driver’s comfort. The damping of the MR damping unit increases gradually as the current applied to power the electromagnetic coil increases, the relative rotation between the shaft and the cylinder of the damping unit will become increasingly difficult In this case, the deformation of the torsional spring will increase under the same external excitation and the VS MR rotary damper will perform higher stiffness. The factors affecting the performance of the seat suspension mainly include the applied DC current to the magnetic coil of the rotary MR damper, the displacement amplitude and the loading frequency of the external vertical excitation. Figure reflects the phenomenon that the viscous damping is sensitive to the current variation but less sensitive to the variations of displacement amplitude

EVALUATION OF THE VIBRATION ISOLATION PERFORMANCE

CONCLUSION

DATA AVAILABILITY STATEMENT