A pendulum-based rotational energy harvester for self-powered monitoring of rotating systems in the era of industrial digitization

Wireless condition monitoring of rotating systems, including vehicle powertrains and wind turbines, is a key for continuously assessing the operational performance in the era of industrial digitization. However, one of their major challenges revolve around the dependence on power supply from batteries. Hence, this paper presents the concept, theoretical model, and experimental study of a pendulum-based energy harvester for high-speed rotational systems. The proposed design harvests energy from rotating shafts by using a suspended eccentric pendulum-based configuration and requires only one anchor point with the host to extract mechanical energy. A numerical model was established to study the dynamics and the electromechanical properties of the harvester. An experimental prototype was developed based on the key parameters determined from the numerical study and mounted on an electric motor-driven shaft for testing. The fabricated device was able to stably operate up to 250 rad/s input speed with an eccentric mass as low as 30 g where 104.5 mW RMS was measured through 450Ω resistive load. An analytical model is developed to outline the critical operating conditions and relationship between the design parameters. Finally, a self-powered wireless sensing system is established employing the harvester to measure temperature data near the operating environment.