Research On The Impact And Vibration Energy Harvesting

With the rapid development of wireless sensor network nodes,various ultra-low-power electronic devices are deployed in farms,forests,deserts,and oceans.These devices are currently powered by various chemical batteries,but with time of useing.The replacement problem after the battery life is exhausted will be very serious.The shortcomings of battery power supply have become increasingly prominent.It has become a research hotspot to develop self-powered technology that collects energy from the environment and continuously supplies energy to power equipment.The various impacts in the environment are an irregular source of energy with a short duration.A vibration can be seen as a superposition of multiple impacts.The previous effects of impact and vibration energy collection are not satisfactory.Since the piezoelectric transducer with the piezoelectric vibrator as the core has a strong correlation between the electromechanical conversion efficiency and the vibration frequency,the closer the external excitation frequency is to its resonance frequency,the higher the conversion efficiency of the transducer and the larger the output voltage.Generally,various impacts and vibrations in the environment are not stable.This paper proposes an impact and vibration energy collector using a mechanical vibration frequency stabilizer,which aims to convert irregular mechanical energy into a continuous stable vibration output and drive the piezoelectric vibrator transducer generates electrical energy.The mechanical vibration frequency stabilizer stores the varying input mechanical energy in the spring,and then stabilizes the stored energy in a controlled manner through a series of precision gear sets with the drive wheels and jaws.The mechanical vibration of the output excites the piezoelectric vibrator to generate electricity to achieve the purpose of generating electricity by using impact energy.Finally,a rectifier bridge and a DC-DC converter are designed as interface circuits,and the alternating current generated by the piezoelectric vibrator is converted into direct current and stored in the super capacitor.In this paper,the dynamic characteristics of the impact and vibration energy collectors are theoretically analyzed.The input characteristics,output characteristics and frequency stability effects of the system are studied.The method of adjusting the output frequency is analyzed and tested.The design of the interface circuit.On the basis of designing the three-dimensional model,the new components such as laser cutting and 3D printing were used to process the components required for the test prototype,and the energy collector structure and interface circuit were completed,and the system was tested in detail.The experimental results agree well with the trend of theoretical analysis.The test shows that the impact and vibration energy collector can stabilize the output frequency change rate within 33%when the input frequency changes by 436%,and verify that the output power is on the order of 6?W/cm~3.The prototype of the laboratory proved that the concept of stable frequency is feasible.