Robust optimization of a dual-stage bistable nonlinear vibration energy harvester considering parametric uncertainties

This study investigates robust optimization of a dual-stage bistable energy harvester (BEH) considering parametric uncertainties, so as to efficiently search the robust optimal design parameters for enhancing vibration energy harvesting performance in a working bandwidth. Dynamic model of the dual-stage BEH and numerical method of predicting the broadband power transmissibility are presented, the fidelity of which is verified by the analytical solutions and experimental results. Then, the optimization problem is defined, where the performance index for optimization is calculated based on the power transmissibility in a working bandwidth. To ensure the robustness of optimization results, instead of straightforward maximizing the performance index, the genetic algorithm is used to maximize the mean value of the performance indices corresponding to the parametric uncertainties which satisfy normal distribution. Results show that compared to the optimization disregarding the uncertainties, the proposed robust optimization method can significantly enhance the overall performance and robustness of the dual-stage BEH subjected to the parametric uncertainties. Therefore, the comparative results validate the effectiveness of the proposed method for robust optimization of the dual-stage BEH.