Investigation of Gravitational Energy Harvesters for IoT Power Supply in Freight Train Monitoring

Recent advances in technology make energy harvesting a promising power supply solution for IoT devices. An electromagnetic gravitational energy harvester prototype for railway monitoring applications is proposed. The main components of the autonomous IoT sensorized node are described. Laboratory dynamic tests and simulations show the harvester resonance frequency and maximum scavenged power for supplying the node. Experimental vertical vibration data collected onboard of a freight railcar are used for harvester frequency tuning and real performance evaluation. The node power management and rectification system is studied to choose the best smoothing capacitor. Experimental battery charge tests under the real onboard excitations are performed and the duty cycle of the autonomous IoT node is defined.