Energy Harvesting for Asset Condition Monitoring and Remote Sensing in the Rail Industry

Significant advances have been made in the field of vibration energy harvesting. The efficiency of microgenerators has reached a stage where they can be considered as reliable power sources for demanding sensing applications. When combined with low power electronic sensors, ultra low power signal processing and radio communications, the potential for an autonomous sensor operating without batteries or wires is now a reality. The railway industry faces a number of challenges which will require autonomous sensors and innovative power sources often in hostile environmental circumstances. The paper introduces the fundamental operating principles of vibration energy harvesting (VEH), and includes initial results from field trials on fixed frequency vibration sources. Further field tests have been undertaken on broadband vibration energy sources such as those found in transport applications. Initial results indicate that energy harvesting in the sub 20 Hz frequency band can deliver useful levels of power and can realistically support remote long-range autonomous sensing applications. The key benefit of the microgenerator is the ease of inservice installation and hence low cost and minimal downtime for the rolling stock. An outline architecture for an autonomous sensor condition monitoring application is presented