Design And Realization Of Swing Low Frequency Energy Harvester

With the vigorous development of smart products today,wearable devices have shown great advantages,and it may replace traditional electronic products as the mainstream of the future market.However,this kind of device still has the problem of power supply.At present,most wearable devices are powered by traditional chemical batteries or external charging cables,which not only have weak battery life,but also bring many changes.Or for devices used inside the human body,this power supply method is not only difficult to replace the battery,but also brings great hidden dangers.At present,the most commonly used solution is to use the combination of energy harvesting technology and wearable devices to realize the self-powering of wearable devices.In daily life,the mechanical energy of human motion is the most stable.It is not affected by weather,time,location and other factors,and it can be perfectly integrated with wearable devices,which is the best choice.Based on the above points,this thesis starts from the design of the rocking low-frequency energy harvester,establishes its finite element simulation model,optimizes the design of the energy harvester,and studies its processing and assembly methods.The energy harvester is subjected to different accelerations and different frequencies.The low-frequency vibration test,and finally the actual wear test on the human body,The main research contents are as follows:On the one hand,a rocking energy harvester with an eccentric pendulum structure as the core is designed based on the principle of electromagnetic power generation,a finite element simulation model is established,and the physical field of "rotating machinery-magnetism" is selected,and the magnetic potential distribution field in the finite element model is calculated.,The magnetic field intensity distribution of the system is obtained,and then the power generation of the energy harvester is solved by the relative rotation of the stator and the rotor.At the same time,the multi-body dynamics physics field is introduced to simulate the motion trajectory and power generation of the energy harvester when the human arm swings,and the two physics fields are weakly coupled to complete the simulation of the motion of the energy harvester worn by the human body.Through the simulation data,the optimal design size of the coil is determined,and the optimal processing method and the most reasonable assembly method of each component are explored.On the other hand,the low-frequency vibration test and the actual wear test of the external environment were carried out on the prototype of the energy harvester.The feasibility of the design is verified,and it meets the requirements of wearable devices.When the human body is running,the output voltage value of the energy harvester is above 11 V,and the average output power value is above 11 m W.In a normal walking state,the output voltage of the energy harvester is about 3.42 V,and the corresponding average output power value is about 3.6m W.Even in the walking state,the output of the energy harvester can still drive some low-power sensor devices,such as ultra-low-power heart rate sensors,acceleration sensors with pedometer function,etc.Therefore,energy harvesters with a rocking structure have certain development prospects in the collection of low-frequency vibration energy and in the field of wearable devices.