Using artificial gravity loaded nonlinear oscillators to harvest vibration within high g rotational systems

Abstract

Energy harvesting within rotating environments can help to enable self-powered wireless sensing, which has been motivated in recent years by the advent of legislations mandating tyre pressure monitoring systems for automotive wheels. The centripetal acceleration (a = ωr 2) within such rotational systems can attain 1,000's of g, which manifest as artificial gravity and can adversely suppresses the dynamic motion of oscillators. This paper investigates the possibility of using the high g conditions as a means of introducing nonlinear bi-stability, which can then allow an oscillator to benefit from a broadband response as well as mechanical amplification achieved from the bi-stable snap-through states. An experimental proof-of-concept prototype was designed, built and tested. By controlling the rotational speed ω of the apparatus, the masses of oscillators experienced a g-force of up to 90 g. Purely by increasing ω, an increase in transducer output was observed from the predicted amplification effect. However, beyond a certain threshold, output dropped to minimal as the potential barrier reached an insurmountable level. This work validates the proposed new mechanism that taps into the high g environment and opens a new avenue of design for vibration energy harvesting within rotational systems.