Modeling of Piezoelectric Energy Harvesting from an L-shaped Beam-mass Structure with an Application to UAVs

TLDR

Piezoelectric energy harvesters based on cantilevered beams have been widely studied. The study introduces the L‑shaped beam‑mass structure as a novel harvester and develops a linear distributed‑parameter model to predict its voltage and displacement responses. The authors derive a coupled distributed‑parameter model, tune the structure so its first two natural frequencies are close for broadband harvesting, and evaluate its power output in a landing‑gear case study for UAVs. The L‑shaped harvester landing gear outperforms the curved‑beam design in the case study, demonstrating its suitability for UAV applications.

Abstract

Cantilevered piezoelectric energy harvesters have been extensively investigated in the literature of energy harvesting. As an alternative to conventional cantilevered beams, this article presents the L-shaped beam-mass structure as a new piezoelectric energy harvester configuration. This structure can be tuned to have the first two natural frequencies relatively close to each other, resulting in the possibility of a broader band energy harvesting system. This article describes the important features of the L-shaped piezoelectric energy harvester configuration and develops a linear distributed parameter model for predicting the electromechanically coupled voltage response and displacement response of the harvester structure. After deriving the coupled distributed parameter model, a case study is presented to investigate the electrical power generation performance of the L-shaped energy harvester. A direct application of the L-shaped piezoelectric energy harvester configuration is proposed for use as landing gears in unmanned air vehicle applications and a case study is presented where the results of the L-shaped — energy harvester — landing gear are favorably compared against the published experimental results of a curved beam configuration used for the same purpose.