Design and experimental study of piezoelectric vibration energy harvester with variable pitch beam

In view of the shortcomings of wired sensing equipment used by roadheaders, such as difficult power supply and difficult to replace power supply under complex working conditions, the vibration signal of the cutting part of a roadheader is collected and analyzed by using the environmental characteristics of strong working vibration of a roadheader, and a piezoelectric vibration energy harvester with variable pitch beam is proposed. Based on theory and simulation, experimental verification was carried out to explore the influence of different structural parameters on the output characteristics of the energy harvester. Through the application experiments of the energy trapping structure and interface circuit array installation, the feasibility of the energy trap to supply power to the wireless sensing node of the roadheader is demonstrated. The experimental results show that the designed array energy harvester has a higher voltage output at 13-15 Hz, and a better output effect at 70 kΩ load, with an output power of 5.6 mW. Finally, the power supply experiment of the energy trap is carried out to verify that the designed energy trap meets the power supply requirements of the low-power acceleration sensing node and is highly matched with the vibration signal characteristics of the roadheader under working conditions, and the energy acquisition efficiency is higher, which is of great significance for the health monitoring of the underground roadheader.