Research On Energy Harvesting Management Method Of Self-powered Mechanical Vibration Wireless Sensor Network

The mechanical vibration wireless sensor network is a distributed sensor network with the characteristics of self-organization,convenient deployment,and strong dynamics.It has huge application potential in special environments such as rotation,airtight,high temperature and high pressure.The mechanical vibration wireless sensor network nodes generally adopt battery-powered or wired-powered power supply,and it is difficult to monitor the monitored objects for a long time in special environments such as the inside of the bearing.By collecting and utilizing the vibration energy widely existing in the mechanical test environment,the service life of the node can be improved and it is expected that the node can be self-powered.In order to solve the energy supply problem of the current mechanical vibration wireless sensor network,and to realize the self-powered mechanical vibration wireless sensor network as the goal,this paper has carried out the research on the energy harvesting management method.The specific work is as follows:Aiming at the problem that the current energy acquisition circuit is difficult to self-start or the energy consumption is too high when the energy consumption of the node system is exhausted,a low-energy cold start method of the vibration energy harvesting system is proposed.First,it analyzes the start-up process of the energy-depleted energy acquisition circuit.The energy loss mainly comes from the loss of the energy module switch due to its insufficient control voltage and the loss of the circuit device itself.Then a voltage reference source with a rapid rise in voltage without external energy is designed;the voltage of the energy storage module and the reference source voltage are used as the two input signals of the internally powered hysteresis comparator to ensure that the storage module can be set when its voltage reaches one.It turns on at a certain threshold.At the same time,reasonable selection of circuit components reduces the energy loss caused by the device itself,and ultimately ensures that the energy acquisition circuit can realize low-energy self-starting.Aiming at the problem that the current energy management circuit cannot accumulate and supply energy in time according to the energy demand of the node task,an energy management system adaptive energy supply method is proposed.A plurality of energy storage modules are formed into an energy storage module array in the order of energy storage capacity from small to large.First,accumulate energy to the minimum capacity module,monitor the current energy state of the energy storage module,and automatically turn on the energy storage switch of the subsequent energy storage module when its voltage reaches a fixed value,ensuring that the node can quickly accumulate energy to respond to unknown tasks.The node can also turn on the energy storage switch of a specific energy storage module according to the known task energy demand to accumulate enough energy to perform the task.In the case of limited energy supply,the node can adaptively select the appropriate energy storage module according to the different energy consumption requirements of the task,and finally realize the purpose of accumulating and supplying energy in time.The wireless sensor network node,energy acquisition device and energy acquisition management circuit are integrated into the system.Experiments have verified that the self-powered node system can effectively collect vibration energy in the mechanical test environment to power itself,and can collect mechanical vibration signals and transmit vibration data.