A vibration energy harvester for freight train track self-powered application.

The safe and stable operation of the widely distributed freight trains urgently needs to solve the power supply problem of the freight train track monitoring network. In this article, an innovative and efficient energy harvesting mechanism is designed based on a mechanical vibration rectifier (MVR), with four modules of motion conversion, motion rectification, generator, and storage. The motion conversion module converts the linear vibration of the rail into rotational motion through the ball screw. The motion rectification module integrates mechanical rectification and transmission speed-up and converts the bidirectional rotation of the transmission shaft into a faster unidirectional rotation of the generator. Experiments show that the power and mechanical efficiency of the proposed vibration energy harvester can reach 28.0416W and 75.92%, respectively. This high-performance MVR can meet the power demand of wireless sensor networks by harvesting vibration energy to ensure the normal operation of freight trains.

An extended-range wave-powered autonomous underwater vehicle applied to underwater wireless sensor networks.

The autonomous underwater vehicle has widespread applications in marine resource exploration, seabed search and rescue, underwater military reconnaissance, and marine environmental monitoring. Owing to the limited battery capacity, autonomous underwater vehicles usually only operate for several hours or days at a time. This article presents an extended-range wave-powered autonomous underwater vehicle (WPAUV) for underwater wireless sensor networks. Through theoretical analysis, simulation, dry and field experiments, the power generation performance of the extended-range WPAUV was evaluated. Under different wave amplitudes and wave frequencies, the mechanical efficiency of the extended-range WPAUV ranges from 20.41% to 81.56%. The average efficiency is 45.35%. In the field experiments, under calm ocean conditions, the maximum instantaneous power can reach 67.74W with an average of 10.18W. This high performance manifests that the extended-range WPAUV can effectively scavenge wave energy and converts it into electrical energy for expanding the cruising mileage.