Vibration Control with a Tunable Self-Sensing Electromagnetic Shunt Damper

Vibration damper is very useful in suppressing excessive vibrations in machines and dynamic structures. Viscous damper is the most commonly used vibration damper in industry but the damping coefficient of commercial viscous dampers is fixed once they are produced. It is useful in many industrial applications of vibration dampers if their damping coefficients can be adjusted easily in order to suit different damping requirements. In this paper, a tunable electromagnetic shunt damper (EMSD) with selfsensing capability is proposed, designed and tested experimentally. The proposed damper can provide a damping force proportional to its vibration velocity and therefore it can be used as an alternative of viscous damper. The damping coefficient of the proposed damper can be varied easily either manually or automatically. Both the damper coefficient and the vibration velocity of the proposed damper can be measured from its output voltage. The EMSD velocity sensing accuracy is comparable to a standard accelerometer and a laser displacement sensor.