Investigation of the passive electromagnetic damper

In this paper, the electromagnetic damper (EMD), which is composed of a permanent-magnet DC motor, a ball screw and a nut, is considered to be analyzed as a passive damper. The main objective pursued in the paper is to determine the EMD characteristics in order to improve the vehicle performance. The effects of the EMD characteristics on ride comfort and road handling are investigated first, and then, the effect of a spring installed in series with the EMD to alter the EMD performance is observed. In order to study energy regeneration, the nonlinear equations of the modified passive electromagnetic suspension system (PEMSS) are extracted. The results of simulation show that the designed passive EMD maintains the desired performance while vibration energy from the road excitation can be regenerated and transformed into electric energy.