Design And Implementation Of Low Frequency Driven Cantilever Beam Vibration Energy Collector

In recent years,wireless sensing technology has been widely used in various fields due to its strong environmental adaptability,low power consumption,and independence and durability.However,the problem that the traditional battery power supply time is short and must be replaced frequently limits the development of this technology.Energy harvesting technology is a good way to solve this problem.Light energy,ocean energy,temperature difference energy,vibration energy and other energy are common in daily life,but vibration energy is widely used in various equipment because it is not limited by the environment.There are three main types of vibration energy harvesters,namely piezoelectric,electromagnetic and electrostatic.Piezoelectric energy harvesters have the advantages of large output voltage,high energy density,easy integration with MEMS,and strong environmental adaptability,which is a very suitable choice for this topic.In view of the inconvenience of low-frequency vibration energy collection in the environment,this paper considers low-frequency drive as the research focus.The design of this subject contains two cantilever beam structures with different characteristic frequencies.The long beam is an ordinary cantilever beam,the characteristic frequency is relatively low,and it plays the role of driving;while the short beam is a piezoelectric cantilever beam,the characteristic frequency is relatively high,and it is responsible for collecting the vibration energy caused by the driving;the permanent magnet is used as the mass of the cantilever beam,The two cantilever beams with widely different characteristic frequencies are coupled as a whole by a magnetic field.The external vibration energy is collected by the long beam and transmitted to the piezoelectric cantilever beam through the magnetic field,thereby generating the output of electric energy.The conversion from low frequency vibration to high frequency is also completed in this process.The piezoelectric cantilever is the core structure of the whole system.It finds the optimal size by characteristic frequency analysis and is suitable for the vibration frequency of the environment.Through the analysis of the influence of the resistance and acceleration on the output power,the most suitable load resistance and acceleration parameters are found.After long beam and short beam modeling and simulation,magnetic field coupling,the overall structure of the system needs to be simulated.A series of performance parameters are obtained by simulating the geometric model of the overall structure,potential distribution,output voltage transient characteristics,magnetic transient characteristics,and flux density mode changes.Finally,through the production of low-frequency driving cantilever vibration energy harvester,designing the subsequent energy harvesting circuit,building a vibration table test system and other measures,the physical test of the energy harvester was carried out,and verified by comparison with the simulation results.The correctness of the modeling simulation.For the piezoelectric cantilever beam,the output power reaches a maximum value of 1.67 mW at a vibration frequency of91.5Hz,a load resistance of 18.1k?,and an acceleration of 1g.For the entire system structure,the frequency is increased,and the signal input frequency is At 2 Hz,the output signal has a frequency of 91.5 Hz and an output power of 0.71 mW.