Energy recovering form vibrations in road vehicle suspensions

Over the last years, energy saving has become a very important issue. One possibility for limiting energy consumption is recovering it from systems where it is dissipated (energy harvesting). One of the most effective methods for implementing energy harvesting is to convert kinetic energy produced by mechanical vibrations into useful electric energy which can be stored in accumulators and then used to power sensors and/or active systems and/or on board auxiliary electrical loads. The application of an energy harvesting device to a road vehicle suspension system is presented in this paper. The device consists in a mass damper excited in resonance, a linear permanent magnet alternator and a power factor controlled rectifier (electromagnetic vibration driven generator). In a first stage of the research, the capability of the device of recovering energy from road induced vibrations of the suspension unsprung mass has been explored. The parameters of the device have then been tuned in order to optimize energy harvesting, taking into account the physical constraints concerned with the application (suspension geometry, electromagnetic vibration driven generator mass, etc.).