Jiamei Nie

A Semiactive Skyhook-Inertance Control Strategy Based on Continuously Adjustable Inerter

This paper presents a modified skyhook-inertance control strategy which is realized through a hydraulic device of continuously adjustable inertance between sprung mass and unsprung mass. The parasitic damping inherent in the hydraulic device as well as the inertance is taken into account in the modified control strategy. Differential equation models are built to compare the performance of the semiactive suspension employing the modified control strategy with that of the passive suspension. The results demonstrate that the semiactive suspension significantly reduces sprung mass natural frequency, attenuates the resonant peak value without the penalty of deterioration at higher frequencies, and achieves over 28% improvement on ride comfort, compared with the passive suspension in unload condition. The proposed hydraulic device, together with its control strategy, can be used to reduce the variation of sprung mass natural frequency and ride comfort between unload and full-load condition.

Application of multi-variable grey model in the integrated control of vehicle SAS and EPS

In order to eliminate the time lag in the integrated control of SAS and EPS, MGM(1,n) model was introduced into the integrated control system to predict the output performance index. It was compared with GM(1,1). In the MGM(1,n) model the mutual influences among the output performance were considered which can improve the prediction accuracy. The control strategy of the integrated controller was adjusted in real-time based on the predictive value. The simulation results show that, the predictive value of MGM(1,n) model is closer to the measured value, the integrated control of SAS and EPS system based on MGM(1,n) model can eliminate the time lag in effect and improve the vehicle handing performance.