Research on piezoelectric energy harvester based on coupled oscillator model for vehicle vibration utilizing a L-shaped cantilever beam

Piezoelectric energy harvester can replace the battery and provide energy for most kinds of micro devices. And due to its advantages of considerable output power and high output voltage, it has bright prospects. This paper presents a piezoelectric energy harvester based on coupled oscillator model utilizing a L-shaped cantilever beam to collect the vibration energy of the vehicle with the frequency band from 5 Hz to 25 Hz. The finite element analysis of the designed piezoelectric energy harvester is carried out by running ANSYS simulation software, including modal analysis, transient response analysis and harmonic response analysis. The results shows that under the coupling, the amplitude-frequency characteristic curve of each oscillator has two peak points, which widens the working frequency band of the energy harvester. Meanwhile, experimental research is carried out on the collector prototype. By analyzing the experimental results, the natural frequency of oscillator 1 is about 17.1 Hz, and the natural frequency of oscillator 2 is about 21.1 Hz. Therefore, these natural frequencies meet the need to collect vibration energy of 5 Hz to 25 Hz. In addition, by comparing the frequency response curves of the open circuit output voltage of the energy collectors working independently and under coupling, the results show that the operating frequency band of the energy collector is broadened under coupling.