Research And Experimental Of Ratchet Type Bidirectional Coaxial Human Motion Energy Harvester

There is a lot of wasted energy in the natural environment,including vibration,sound,wind,solar,tidal,and human movement energy.Therefore,it is feasible and practical to recover energy from the natural environment and replace the traditional battery to power electronic devices,which is in line with the modern concept of sustainable development.For portable,wearable and stationary devices,the human body itself is a huge treasure trove of energy,involving thermal,mechanical and biochemical energy.The mechanical energy of the human body is the most widely and readily available.Therefore,many scholars have worked on the collection of energy from human movement.Therefore,this paper proposes a ratchet type bidirectional coaxial human motion energy harvester with the background of densely populated places such as squares and stations.The research objective of converting human motion energy into electrical energy instead of traditional batteries to power low power consumption devices.The human motion energy harvester has the characteristics of bidirectional energy recovery,high output voltage,high output power,and high energy conversion efficiency.Then the energy harvester is developed,based on which the power generation performance of the energy harvester is analyzed and relevant experimental studies are done.Firstly,this paper introduces the energy harvester energy input human motion characteristics and energy output DC motor characteristics,the human motion energy generation,consumption,energy collect principle and motor armature potential,electromagnetic torque analysis.On the basis of which to establish the system dynamics equations.To achieve clean energy recovery and reuse,the development of ratchet type bidirectional coaxial human motion energy harvester was launched.According to the technical index requirements,determine the overall scheme of the human movement energy harvester.On the basis of which the detailed structural design of the harvester’s energy storage reset system,transmission system,bidirectional to unidirectional system,energy collector and energy storage stabilization system,spindle and auxiliary structure,so that the energy harvester meets its technical index requirements.Using Creo software to simulate the feasibility of the energy harvester,verify the completion of the parts out of the drawing processing and assembly,debugging to complete the prototype installation.Next,the power generation performance of ratchet type bidirectional coaxial human motion energy harvester is analyzed,and the kinematic model of bidirectional to unidirectional system is established to study the relationship between the input displacement of the energy harvester and the spindle speed of the energy harvester.The kinetic model of human motion energy harvester is established to study the linear damping coefficient of the energy harvester,and the equations of motion of different motion stages of the energy harvester are derived.According to the different motion states of the energy harvester,analyze the energy conversion relationship during the motion of the energy harvester,derive the output voltage of the harvester during different motions,and explore the factors affecting the output voltage magnitude of the harvester.The power generation and energy conversion efficiency of the harvester in the bidirectional energy recovery process are analyzed separately to derive the overall recovery efficiency of the harvester.Finally,in order to verify the energy recovery performance and reliability of the ratchet type bidirectional coaxial human motion energy harvester proposed in this paper.To simulate the effect of the real human body acting on the device,a test platform of the human energy harvester was built in the laboratory environment.On this basis,the random human motion energy recovery test is completed to prove the bidirectional recovery effect of the harvester.The power generation characteristics test of the harvester is used to verify the structural parameters of the harvester and the influence of external factors on the output performance of the harvester.The load characteristics test of the harvester is used to verify the load carrying capacity of the harvester,and the output power and energy conversion efficiency test of the harvester.The experimental results showed that downward and upward voltages of 18.2 V and 19 V were obtained at a downward frequency of 3 Hz,respectively.When the external force is 160 N,the downward and upward powers obtained are 5.10 W and 7.04 W.The energy recovery efficiency of the human energy harvester is 72.26%.The obtained energy is stored in a supercapacitor and continuously and stably powers the sensor and LED.