Optimization and OGY-based chaos control of a bistable piezoelectric energy harvester for enhanced power generation

This study investigates the nonlinear dynamics and energy-harvesting performance of a bistable piezoelectric energy harvester. The work was motivated by the need to improve the power output and dynamic predictability of piezoelectric harvesters operating under nonlinear and potentially chaotic conditions. Numerical simulations were performed using the STONEHENGE software, and systematic parameter scans were conducted to examine the system response under different excitation and coupling conditions. Instead of treating the excitation amplitude and frequency as directly controllable design variables, the analysis was used to identify how the harvester responds over a representative range of operating conditions and how its performance can be improved through suitable physical and nonlinear system parameters. A Python-based optimization algorithm was then implemented to evaluate the parameter combinations associated with improved energy-harvesting performance within the simulated parameter domain. The revised analysis therefore focuses on performance trends, nonlinear coupling effects, and control-oriented stabilization rather than reporting specific excitation conditions as practical design targets. The results showed that the nonlinear coupling coefficient β plays a decisive role in determining energy-harvesting efficiency, indicating that nonlinear coupling can be exploited to enhance power generation. Within the investigated numerical framework, the optimized response reached a maximum power output of 69.052 mW, demonstrating the potential benefit of parameter-guided nonlinear tuning. In addition, the Ott-Grebogi-Yorke control method was applied to suppress chaotic oscillations and stabilize the system into a periodic regime. This transition from chaotic to periodic motion improved the predictability of the generated electrical response. The findings demonstrate that optimized bistable piezoelectric systems, combined with chaos-control strategies, offer a promising route for efficient and reliable vibration-based energy harvesting.