High frequency energy transfer in semi-active suspension

This paper investigates the effect of unintended high frequency excitations generated by the semi-active sky-hook control algorithm on the isolation properties of a car suspension. Using a quarter car model, an energy transfer from low to high frequency is established. An alternative algorithm is presented in this paper, in order to achieve smooth variations of the control force. Compared with the continuous semi-active sky-hook, the algorithm has been found to provide a similar damping of the body resonance, but also a better isolation at high frequency and global comfort.