A Study Of Semi-active Seat Suspension Based On Magneto Rheological Damper

The seat suspension is an important part of the vehicle, which significantly impacts the ride comfort. By now, it has become an effective way to improve the ride comfort of vehicle via promoting the damping performance of seat suspension.The semi-active seat suspensions get extensive attention by researchers and engineers recent years due to the high cost and complex structure of the active seat suspension, and the limited performance of the passive suspension. The semi-active seat suspension with magnetorheological fluid(MRF) damper has become a research focus because it has the advantages of easy processing, simple structure and good control ability. The semi-active seat suspension based on MRF damper is investigated in this thesis, and the work includes the follows:(1) C-class road model and seat suspension system model are established, which is the foundation for model of the semi-active seat suspension system.(2) Some experiments are conducted to study the dynamic features of a selected MRF damper. The hyperbolic tangent function-based model of the MRF damper is identified by using parameter fitting which is achieved with Matlab. Dynamic simulation for the model of the given MRF damper is accomplished. The experiment results are compared with that from the simulation to verify the model based on hyperbolic tangent function-based model. The results show that the model is right.(3) Basic theories of skyhook control and LMS adaptive control are investigated. Two control programming which are applied to the semi-active seat suspension based on MRF damper are developed, and the characteristics of the two control methods are analyzed(4) The simulation model of the semi-active seat suspension based on MRF damper is established by using Matlab/Simulink tool. The performance of the two control plan applying on the simulation model to control the seat vibration is studied and the performance of these two control plan is compared.