A Novel Switchable Suspension Inspired by Duffing Oscillator

Inspired by the duffing oscillator, a novel suspension is proposed, which could realize the softening/hardening spring, and could switch between passive, semi-active and active control mode of suspension solely through control of the electric motor. The mathematical model of quarter vehicle suspension is given to express the suspension at different modes. Then the equivalent linear approximate model (ELAM) [1] is introduced and the switching between the semi-active suspension and passive suspension is realized through the idea from the model. The ELAM model is validated numerically by the comparison of simulation between ELAM and sky-hook control model. To further validate the proposed switching method, a scaled suspension test rig is developed, the idea of the switchable suspension is implemented by the control of the servo motor equipped in the rig, the switching experiment result agrees well with the simulation.