Optimized and Robust Orbit Jump for Nonlinear Vibration Energy Harvesting

Abstract

This paper introduces an optimized orbit jump strategy for nonlinear Vibration Energy Harvesters (VEHs). Nonlinear VEHs are a promising alternative to linear VEHs due to their broadband characteristics. However, they exhibit complex dynamical behaviors, including not only high-power inter-well orbits but also low-power intra-well orbits and chaos. The existence of low-power orbits in their dynamics can restrict their energy harvesting performance. In order to overcome this issue, this study investigates an orbit jump strategy that allows the VEH to transition from low-power intra-well orbits to high-power inter-well orbits. This strategy, based on varying the buckling level of a bistable VEH, has been previously studied but not yet optimized. In this study, we define an optimization criterion that maximizes both the effectiveness and robustness of the orbit jump strategy. We developed a Python CUDA code using GPU parallel computing to handle the large number of numerical resolutions of the nonlinear VEH model. Experimental tests were performed on a bistable VEH over a frequency range of 30 Hz, validating the numerical results obtained with the optimized orbit jump strategy. The results indicate that the energy consumption required for a successful orbit jump ranges between 0.2 mJ and 1 mJ, and can be restored within 0.2 s in the worst case. Experimental results show an average success rate of 48%, despite a variation of ±15% in the starting and ending times of the jump, leading to a robust and optimized orbit jump strategy. The proposed optimization procedure can be applied to other orbit jump strategies, and other types of nonlinear VEHs.