Magneto-Rheological Material

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

Overview: We design a semi-active vehicle suspension with a stiffness variable self-powered MR damper, which can vary the stiffness of the suspension. In order to convert the mechanical vibration into the electric power to support the MR damper, the energy harvesting structure coupled a ball-screw bearing with a rotary generator. The working principle and the mathematic model are presented.

After the prototype of the suspension, experimental tests were conducted to evaluate its stiffness variable feature and self-powered generation capability using a hydraulic INSTRON test system.

The testing results show that the self-powered generation component can produce electric power, which is sufficient to vary the stiffness of the suspension under the rectified-supply mode, but not effective to change the stiffness of the suspension under the direct-supply mode.

Finally, by employing the quarter-car test system, several tests of the suspension were conducted to investigate the feasibility of the control strategy of the Short Time Fourier Transmission (STFT). If the main frequency of road excitation exceeded or decreased to a threshold value, the rectified-supply mode of self-powered would be switched off or applied to vary the stiffness of the suspension to keep the relatively low transmission and avoid the system resonance.

The result illustrates that STFT control with self-powered energy, compared with the passive system, is feasible and effective to reduce 16.8% acceleration RMS and 21.4% displacement RMS.

References

• Zhu, X., Ning, D., Hao, Z., Huang, H., Sun, Y.Z., Jia, H., Sun, S., Yan, T. and Li, W., 2021. Modelling and experimental evaluation of a variable stiffness MR suspension with self-powering capability. Journal of Intelligent Material Systems and Structures, 32(13), pp.1473-1483. (Article link)