Design and multi-physics optimization of an energy harvesting system integrated in a pneumatic suspension

This paper describes a research activity concerning the design and the development of an energy harvesting system integrated in a pneumatic spring for railway application to recover otherwise wasted energy sources from the train suspension vibration. The final scope of this research is to harvest energy and create a self-powered smart component capable of supplying useful information for the monitoring and the diagnostics of a vehicle or its subsystems. Starting from a common air spring for a metropolitan train application, the boundary volume of the new device was defined by means of reverse engineering techniques. Exploiting commercial component, two alternative transduction mechanisms were evaluated to select the best one in terms of flexibility and functionality. The defined concept design was thus modelled and optimized by means of a multi-physical approach. The reiterative optimization process, based on the use of a specific cost function, led to define the optimized device layout. The effectiveness of the proposed device, in terms of power generation, was evaluated realizing a physical prototype and a test rig. The results of the experimental tests validated the design process.