Energy Harvesting Optimization Using 2-dimensional Car Suspension System Actuated by a Sawtooth Speed Bump

In this work, an optimal suspension system is proposed to reduce the oscillations/vibrations of the car body and harvest some of the induced vibration energy. The usual shock absorbers are replaced with energy harvesters capable of not only absorbing vibrations for ride comfort, but also regenerate electrical energy for onboard use. To investigate the efficiency of the proposed harvesters, the input to the vehicle wheels is assumed to come from a sawtooth shaped speed bump or rumble speed strip. Also, given the coupling between the various degrees of freedom of the car (heave, pitch, etc.), a half-car model is adopted in the derivation of the equations of motion. To maximize the amount of energy harvested, the design parameters of the harvesters are obtained using the Simulated Annealing optimization technique with four objective functions. Many of the design parameters, including magnet size, coil turns, and coil layers, are adjusted during the optimization process. Constant and accelerated motions are considered in this study to maximize the Generated Electricity index (GE) and Ride Comfort Efficiency (RCE). The simulation results showed that the optimized harvesters were able to regenerate a significant amount of energy while maintaining an acceptable ride comfort level.