Small excitation self-powered sensing energy harvester for rail traffic condition monitoring

A small excitation bistable vibration energy harvester for railway transportation is developed for self-powered condition monitoring utilizing low-frequency vibration of key train components. Analyze operational vibration data collected from trains to determine design requirements. A free sliding magnet is placed in a tube with a top fixed magnet and two limit springs, using gravity, magnetism, and spring force to provide two stable positions for the movable magnet. This structure can enter the bistable operating region under small excitation amplitude and has a wide operating bandwidth. Build and test prototypes using conditions similar to real train operating conditions. A wide operating bandwidth (7 Hz-46 Hz) is obtained due to the bistability. Peak output power is 3.17mW measured into a 900 ω resistive load at 30 Hz and 1.4g.