Design and optimization of coupled structural parameters of magnetostrictive bistable harvester

Bistable vibration harvester makes the system have two equilibrium states, thus improving its output characteristics. To further optimize the vibration acquisition capacity of harvester, it is important to identify and optimize the material and structural parameters of harvester. This paper proposes a method to identify the key coupled parameters of mathematical model of designed magnetostrictive bistable vibration harvester with displacement amplification mechanism using the Wild Horse Optimizer. The important coupled structural parameters of the mainly designed bistable structure and displacement amplification mechanism are analyzed and discussed based on identified parameters. In addition, the Wild Horse Optimizer is used for optimization design of three important coupled parameters, including the repulsive permanent magnets distance that constitute the bistable structure, the mass ratio and the stiffness ratio between the displacement amplification mechanism and the bistable vibration harvesting system. Finally, harvester prototype based on the optimized coupling parameters obtained is tested experimentally. The results show that second-order output voltage of the prototype reaches 3.06 V under the excitation of 0.8 g. Compared with the preliminarily designed prototype, the peak voltage is nearly improved 5 times, which further verifies the effectiveness of identifying and optimizing the magnetostrictive bistable vibration harvester with displacement amplification mechanism.