A Self-Powered Wireless Sensor System (SP-WSS) for Real-Time Propulsion Shaft Monitoring

A self-powered wireless sensor system (SP-WSS) integrating a high-power energy harvester (EH) has been proposed for real-time monitoring of the propulsion shaft. The main contribution of this article is to demonstrate that the status of the propulsion shaft can be monitored in real time by integrating a high-power EH that generates power solely from the rotational force of the propulsion shaft. The proposed EH features a simple structure consisting of 12 coils and six magnets, facilitating easy design and manufacturing. The output power of the EH increases in proportion to the number of coils and rotation speed, simplifying the design of the power required for the WSS. The fabricated EH achieved power outputs of 1.5 and 5.1 W at shaft speeds of 200 and 300 r/min, respectively. The complete SP-WSS, integrating the EH, four sensors, a control module, and a radio module, was designed and installed on the propulsion shaft. The SP-WSS accurately measured the power production of the EH, power consumption of the WSS, shaft vibration, temperature changes around the shaft, and shaft rotation speed in real time, successfully transmitting the data wirelessly to a main management system.