Studies on Dynamic Stiffness and Damping of the Vibration Energy Recovery System

The vehicle suspension plays a significant role in alleviating the vibrations translated from the rough road and most of the vibrations are dissipated by the hydraulic shock absorber. Vibration energy harvesting technology is widely concerned for the self-powered wireless sensor system in intelligent vehicle. However, the system dynamic characteristics are influenced by the Ampere force which induced by the electro-magnetic induction of the vibration energy recovery system. Considering the mechanical electromagnetic coupling, a dynamic model of a quarter vehicle with vibration energy recovery system is established. The additional dynamic stiffness and normalized damping characteristics of the electromagnetic system are investigated by applying the harmonic displacement excitations with different frequencies. The time-domain dynamic responses in terms of both the vibration acceleration and suspension deflection under harmonic and square displacement excitations are compared between the two vehicle models with and without the electromagnetic system. It shows that the electromagnetic interaction would result in the frequency dependent dynamic characteristics, which have effects on the system dynamic responses.