Design, modeling and experiments of a double-pendulum vibration energy harvester

Abstract This paper presents a double-pendulum energy harvester designed to convert low-frequency environmental vibrations, such as wave-induced motions on unmanned surface vehicles, into usable electrical energy. The key innovation lies in its double-pendulum-spring configuration, which features a serially connected inverted pendulum with a normal pendulum. This unique design effectively broadens the frequency bandwidth for energy harvesting. The harvester was designed, mathematically modeled, constructed, and experimentally tested, demonstrating effective performance in low-frequency and wide-bandwidth characteristics. Experimental results show that the prototype exhibits two distinct resonance peaks at 0.6 Hz and 1.2 Hz, with corresponding maximum average output powers of 0.250 W and 0.404 W, respectively. Compared to single-pendulum harvesters of the same pendulum length, this design offers the advantage of a broader frequency band, enhancing its energy harvesting potential.