Energy harvesting from car suspension using a single magnet device

The need for renewable energy sources and harvesting devices has increased over the years for environmental and economical reasons. Cars, for example, have gone through important transformations over the past decade, which led to the inception of the hybrid type. The idea is to harness some of the dissipated energy and reuse it to operate a vehicle. A lot of energy is dissipated into the environment from the suspension system; therefore, harnessing that energy could be very useful for powering up electrical systems in a car. A magnetic mass-spring system to harvest the vibrational energy dissipated from the car's suspension system that maximizes electricity generation and minimizes ride discomfort is presented in this work. The comfort level for the passenger via three dimensionless indices, including a regenerated electricity transmissibility, displacement transmissibility performance, and ride comfort performance, is introduced. To maximize the regenerated electricity indicator and minimize the discomfort indices, a multi-objective function based on the above indices and three weighted factors in conjunction with the Simulated Annealing method is used to obtain the optimal physical parameters for the harvesting device. The theoretical developments are demonstrated under constant and varied driving speeds, and the simulation results show that the energy harvester is capable of producing reasonable amounts of electricity while maintaining a good comfort level. In fact, it was shown that the harvester can generate 0.045 V when the car travels at 60 km/h with an acceleration of 0.43 m/s(2) and assumed base excitation amplitude of 0.05 m. Higher voltages were achievable with larger base excitation amplitudes and (or) accelerations.