Ultra-Low Power IoT Sensors for Condition-Based Maintenance

Condition-based maintenance (CBM) systems that use wireless sensors are becoming a popular and useful tool for identifying maintenance needs and preventing system failure. This project presents a vibration-based energy harvesting method to extend the IoT sensor battery life to around three to five years in a railroad operating environment.

The team developed an energy harvesting solution that captures vibrational and solar energy from the operating environment to recharge the IoT sensors in the CBM system. Piezoelectric generators capture the vibrational energy when vibrated at certain frequencies, and solar panels on the exterior of the system capture the solar energy. An onboard microcontroller monitors the incoming harvested energy and connects the source to the rest of the circuit when a certain voltage threshold is met. The battery charging circuit is equipped with a load sharing circuit, which allows power to be shared between the incoming power and battery to power the system.