Research On Control Strategy Of Magnetorheological Semi-active Suspension System

With the improvement of people’s living standard, people has higher requirementin the comfort and safety of cars. The suspension system as an important part ofautomobile, plays a decisive role in the damping effect of the whole car, affecting thecomfort and safety of the car. With the development of the suspension system,magnetorheological semi-active suspension becomes a research hotspot due to its highreliability and superior control close to the active suspension. But the complex nonlinearof the magnetorheological damper limits the development of the semi-active suspension.At present, the studys of its control strategy are mostly skyhook control and activecontrol methods. The skyhook control has improved the performance of the suspension,but did not play the the advantages of the continuously adjustable coulombic force ofmagnetorheological damper. And the active control method can obtain the optimalcontrol, but it often fails in practice. This paper mainly focuses on the control strategystudy of magnetorheological semi-active suspension system.Firstly, the mechanism, working principle and related control methods ofmagneto-rheological damper are discussed. Based on the Bingham model ofmagnetorheological damper, the output force of magnetorheological damper can bedivided into controllable coulomb damping force related to the input current and theuncontrollable viscous damping force related to the system state. The coulomb dampingforce and the current relationship is nonlinear, the viscous damping force can beconsidered as a damper with fixed damping coefficient of the suspension, whichprovides conditions for later further research.Secondly, the suspension model is established, and elaborats the physical meaningof the evaluation system of the suspension system, and the road surface excitation areintroduced. we bulid the the time-domain model of road surface, through numericalsimulation, this paper focuses on the influence of damping coefficient of on car bodyacceleration, suspension dynamic deflection and tyre dynamic load under the road inputdisturbances, the simulation confirms the defects of the passive suspension, highlightsthe significance of this article.Further, in view of magnetorheological semi-active suspension system controlstrategy, the magnetorheological semi-active suspension model based on Binghammodel is established. Through the study of the skyhook control, the simulationimplements the skyhook control can obtain good vehicle ride comfort. We analyzes the state of the system, presents a new control strategy based on the displacementresponse of the sprung mass, which gets a better steering stability, the simulation resultsshow that the car can get good security under the control.Finally, the fuzzy control is put forward, according to the good safety of theskyhook control and the good comfortability of the new control, the fuzzy control rulesare developed, the simulation results verify the effecticeness of the proposed method.