Modelling and experimental evaluation of a variable stiffness MR suspension with self-powering capability

This paper presents the modelling and experimental evaluation of a semi-active vehicle suspension installed with a self-powered MR damper which is able to perform variable stiffness. Its variable stiffness feature as well as the self-powering capability was evaluated and verified using a hydraulic Instron test system. The testing results show that the stiffness of the damper is dependent on the current which can be generated by the self-powering component. A mathematic model was established to describe the dynamic properties of the MR damper and its power-generating capability. Finally, the self-powered MR suspension was installed on a quarter car test rig for its vibration isolation evaluation. A controller based on the short-time Fourier transform (STFT) was developed for the stiffness control. The evaluation result illustrates that the proposed MR damper can reduce the acceleration and displacement of the sprung mass by 16.8% and 21.4% respectively, compared with the passive system.