Modular Environment for Development and Characterization of Tunable Energy Harvesting Systems

Abstract

This paper presents the design and development process for an electromagnetic self-tuned vibrational energy harvester prototype. Most state-of-the-art publications present non-tunable or manually tunable vibrational energy harvesters, even the market provides some commercial models of these categories for specific applications. On the other hand, self-tuned energy harvesters are yet rarely seen on the research community. The presented work follows the complete process of designing a prototype to work as a second-order oscillatory system in the form of a cantilever. Three different approaches to tune the resonant frequency of the harvester were considered, each based in changing a property of the cantilever that modifies its resonant frequency. Firstly, it was changed the effective vibrating length of the cantilever. Secondly it was introduced an axial load to the system. Then, the use of a dual cantilever wishbone structure was studied as it allows changing the equivalent stiffness of the system. Finally a prototype based on the first strategy was built and tested, including control algorithms for the maximum electrical energy harvesting point tracking which are presented.