Realization of Adjustable Damping Characteristic Based on a Magnetorheological Damper

In order to improve the efficiency of damping characteristic adjustment for vehicle suspension shock absorber, the control system with a magnetorheological (MR) damper was proposed to realize the adjustable damping characteristic. The Bingham model of a MR damper was establish based on the damping force of the MR damper under different sinusoidal excitations and different currents. The force-velocity curves of dampers were described with a mathematics model. The whole slope and the curvature of the damping force-velocity curves were represented by separate parameters and could be adjusted independently. An embedded control system was developed to adjust damping characteristic with a speed sensor, a microprocessor, a damping characteristic adjustment module, a MR damper and a current driver. The current driver was designed by taking the voltage Pulse Width Modulation (PWM) as the excitation signal. The verification experiment shows that the overall slope and the rate of curvature change for the peak damping force-velocity curve could be adjusted in a little time delay by this control system.