Research On Four-Degree-of-Freedom Piezoelectric Vibration Energy Harvester Based On Spring Bistable And Parallel Impact Bandwidth Widening

With the development of intelligent construction and microelectronics manufacturing technology,wireless sensor nodes are gradually recognized and applied in various fields due to their small size,light weight and low power consumption.After long-term development,environmental energy harvesting technology has gradually become an alternative solution for power supply of microelectronic devices,making it possible to harvest energy in the environment for long-term power supply of wireless sensor devices.The cantilever piezoelectric vibration energy harvester can effectively harvest the vibration energy near the resonance frequency of the structure,but the working frequency band is narrow and it is difficult to adapt to the complex and changeable working environment.In order to improve the environmental adaptability of the energy harvester,this paper focuses on the nonlinear broadband energy harvesting technology.In this paper,energy capture of four-degree-of-freedom piezoelectric vibration based on spring bistable and parallel collision spread spectrum is studied by synthesizing three broadband methods,multi-frequency response,multi-steady state and mechanical collision.The details are as follows:1.A four-degree-of-freedom piezoelectric vibration energy catcher based on spring bistable state and parallel collision spread spectrum is proposed.The double parallel arrangement of cantilever beam is used to realize the spring bistable spread spectrum.The multi-frequency response and mechanical impact spread spectrum are realized.2.The energy harvester was made,and the mathematical models of electromechanical coupling,spring elasticity and collision force were established.In order to make the dynamic model more accurately reflect the output voltage response of the actual model,the quantum particle swarm optimization algorithm was used to identify the equivalent parameters of the model.3.Matlab was used to solve the nonlinear differential equation numerically,and the output voltage response of different multistable beam spacing was simulated and analyzed.4.A vibration test platform and an interface circuit energy capture test platform were built to verify and analyze the simulation results and the broadband performance of the energy capture device.The research results show that under the external excitation with an acceleration of 0.5g,a sweep frequency range of 5-30Hz,and a sweep speed of 1Hz/min,the four-degreeof-freedom cantilever beam piezoelectric vibration energy harvester SBIP-VEH has a wide frequency band through spring bistable and mechanical impact.The frequency bandwidth of the output power of the SBIP-VEH can reach 238%of the linear array energy harvester above 10μW,and the frequency bandwidth of the output power above 20μW can reach 258%of the linear array energy harvester.Interface circuit experiments show that SBIP-VEH has different load and vibration adaptability when connecting different interface circuits.The output power of the chaotic vibration part is also about 20μW,which meets the power supply requirements of some low-power electronic products.This study provides a broadband scheme of cantilever piezoelectric vibration energy harvester,and provides a new research idea for the development of cantilever piezoelectric vibration energy harvester.