Stochastic resonance energy harvesting from general rotating shaft vibrations

Abstract

Many vibration energy harvesters have been developed in the past to harvest energy from rotating systems. Yet most of these harvesters are linear resonance-based harvesters whose output power drops dramatically under random excitation. This poses a serious problem because a lot of vibrations of rotating systems are stochastic. In this paper, an advanced energy harvesting mechanism is proposed to magnify power output when the excitation is random. Large power output can be produced with stochastic resonance by inputting weak periodic signal and noise excitation into a bistable system. Stick-slip and whirling vibrations which are inherently existing in various rotating shaft systems, are used to make periodic signal and noise excitation. Energy harvester with external magnet was used to compensate biased periodic force from rotating shaft. The proposed energy harvesting approach is particularly useful for high friction and low speed application such as oil drilling. Detailed analysis is conducted to prove the effectiveness of the proposed energy harvesting concept. In addition, experiments were performed to verify the feasibility of this energy harvesting strategy.