Multi-directional vibration energy scavenging via a monostable magnetic rolling pendulum energy converter

Abstract

Because of its minimal mechanical damping, the magnetic rolling pendulum (MRP) mechanism has seen widespread utilization in energy scavenging. However, no studies have yet examined the MRP converter's nonlinear response and performance when exposed to a multi-directional vibrational environment. Therefore, this paper applies the MRP monostable energy converter (MRP-MEC) for scavenging energy from multi-directional vibration. Numerical simulations, utilizing a theoretical model and finite element analysis, indicate that an appropriate excitation angle induces the converter to produce high-amplitude period-1 oscillation at lower frequencies and period-2 oscillation at higher frequencies during sweep frequency excitation. Bifurcation and multi-solution analysis reveal the realization of period-1 and period-2 oscillations being close to the excitation direction, and the initial conditions have a significant influence on the probability of achieving high-amplitude oscillation. Experiments under excitation with different levels agree well with the numerical outcomes. Under the excitation of 0.5 g for an excitation angle of 60°, up-sweep frequency excitation witnesses high-amplitude period-1 oscillation from 4.1 to 8.9 Hz and period-2 oscillation from 8.9 to 19.7 Hz. Under 16.5 Hz/0.5 g excitation, a 4.89 mW maximum average power is attained when a matched resistance is applied, whereas handshaking excitation results in a 4.39 mW peak average power. Charging a 470 μF capacitor using handshaking excitation for 10 s allows the calculator, hygrothermometer, and watch to function for 354, 282, and 2106 s. Furthermore, 150 LEDs could be lit using the MRP-MEC, demonstrating its broad application prospects.