Control between coexistent attractors for optimal performance of a bistable piezoelectric vibration energy harvester

Abstract

Research in broadband nonlinear piezoelectric energy harvesting has gained traction in recent years as resonant, linear harvesters do not operate optimally in dynamic environments. By placing a linear harvester in a symmetric magnetic field, a nonlinear restoring force allows the system to realize motion across two potential wells. Different levels of excitation enable the system to oscillate solely in one potential well, periodically across both potential wells, or aperiodically across both potential wells. Periodic interwell motion is considered desirable for nonlinear energy harvesting systems, however, coexistent attractors inhibit uniqueness of such a solution. The authors have previously shown that chaotic, aperiodic motion between potential wells can be optimized for improved energy harvesting. The technique applied a chaotic controller to stabilize a large amplitude periodic orbit within the chaotic attractor. This work considers the basins of attraction of the two concurrent attractors and applies an intermittent control law in which the system is perturbed from a chaotic, aperiodic interwell response into the desirable large amplitude, periodic, interwell response.