Study On Energy Self-supply And Transmission Optimization Technology Of WSN Node In Farmland Environment

The application of agricultural wireless sensor network in agriculture provides decision-making and application support for agricultural production,which improves the level of agricultural management intelligence,but the energy limitation makes the development speed of agricultural sensor network has been greatly restricted.Therefore,in order to prolong the work cycle of nodes and improve the design of nodes,this paper alleviates the problem of energy limitation of agricultural sensor network from two aspects: optimizing transmission strategy and energy supply,and providing a method for extending the service life of wireless sensor network,This paper mainly completed the following work:1.Optimize the transmission strategy: Analyze the advantages and disadvantages of the typical data transmission algorithm,absorb the advantages of the typical algorithm and improve it,and design the Huffman algorithm based on non-uniform interval transmission.First,we set up an efficient data protocol,Of the environmental information through the multi-threshold judgment,the satisfaction of the data into the corresponding data frame,and a frame of data Huffman compression sent to the convergence node,which by reducing the amount of data sent to reduce node energy consumption.2.Energy self-supply node platform design and implementation: the use of serial connection of two solar panels to convert the amount of sunlight into electricity,the daisy-chain lithium battery pack and its effective management.Hardware design and efficient control of the sun automatic control,daisy chain battery charge and discharge collection and control,battery and LTC6803-4 chip temperature acquisition and control,single battery voltage acquisition,daisy chain battery balance control,sensor interface circuit;Software to achieve the battery charge and discharge current acquisition,battery temperature,chip temperature acquisition,battery voltage acquisition,daisy chain battery balance control,non-uniform interval Huffman compression transmission.3.Huffman algorithm for non-uniform interval transmission: Experiments of data transmission protocol comparison experiment,data compression contrast experiment,non-uniform interval transmission comparison experiment and non-uniform interval transmission experiment and typical uniform interval transmission algorithm are carried out.As a result,the design of the transmission protocol is reasonable,with energy-saving effect,Huffman in the compressed data transmission after reducing energy consumption,in addition,non-uniform interval transmission also reduces the amount of data sent,more realistic reflection of environmental data to prove The rationality and correctness of the algorithm design.4.Energy self-supply test and analysis: respectively,the software calculated charge and discharge current value,temperature value,voltage and multimeter,thermometer measured values were compared to prove the accuracy of the calculated value of the software;The results show that the effect of equalization control is satisfactory.The experiment is carried out to test the charging efficiency under different intensity and light conditions.The charging efficiency of the test period is obtained.The experiment is carried out by using the efficiency of tracking control.It is concluded that the tracking and charging ratio is not filled with the tracking battery pack 30 minutes ahead of time.The continuous discharge experiment of the daisy chain lithium battery pack is carried out,and the life cycle of the node discharge is predicted The energy consumption of each load was tested,and the discharge energy consumption of each load was obtained.Finally,the working time of the lithium battery was tested,and the daisy-chain lithium battery was obtained under the condition of no solar energy.The life cycle is 3.63 days.