Research On Temperature And Humidity Monitoring System Of Agricultural Products Cold Chain Storage Based On Internet Of Things

The loss of agricultural products in China is quite serious.The loss of "the first kilometer" is as high as 15-25%,and the annual loss of the whole logistics link is 300 billion yuan.In recent years,the state has issued a number of policies to promote the construction of cold chain logistics and storage facilities for agricultural products and the monitoring of cold chain storage information.In the construction of cold chain storage facilities: support the improvement of production and supporting storage,fresh-keeping facilities and equipment conditions;Focusing on the "first kilometer" of fresh agricultural products,support new agricultural business entities to build storage and preservation facilities for agricultural products.In terms of cold storage information collection: it is required to collect the storage environment information on agricultural products and transmit it through the Internet.In order to reduce the "first kilometer" loss of agricultural products and realize rural revitalization,the government subsidies vigorously guide agricultural producers to build a cold storage in fields and producing areas,help them reduce costs,increase income and achieve industrial poverty alleviation.After investigation,it is found that the confusion of agricultural products layout,lack of effective pre cooling before and after warehousing,inaccurate temperature and humidity monitoring data and lack of information management are important factors for the loss of agricultural products after picking.Cold storage in producing areas is difficult to achieve effective precooling and cold storage of agricultural products,resulting in shortened preservation period and poor preservation effect of agricultural products.In view of the above problems,the system requirements of multi-point fine temperature and humidity monitoring,real-time uploading of cold storage data to the network and information management of cold chain storage are summarized.Combined with the actual problems and needs,this study proposes a set of temperature and humidity monitoring system for cold chain storage of agricultural products in origin based on the Internet of things,which aims to realize the accurate temperature and humidity monitoring of agricultural products in the cold storage,and share the monitoring data in real time to the owners and warehouse managers of agricultural products outside the warehouse,so as to improve the storage management level of cold storage in origin.Firstly,the hardware structure of temperature and humidity monitoring terminal and intelligent gateway of Internet of things is developed.According to the environment in the cold storage,the combination test of different types of sensors,communication modules and microcontrollers is carried out,and the component combination with the lowest cost and the best effect is selected.Design the circuit structure,layout the PCB wiring,test the electrical properties and package the equipment shell.Then,based on the embedded program of the temperature and humidity monitoring terminal and intelligent gateway of the Internet of things,an efficient and reliable communication protocol and networking scheme are designed,and the wireless ad hoc network for temperature and humidity collection in the cold storage is constructed by using wireless communication technology.Gather and transmit the data collected by the temperature and humidity monitoring equipment to the outside of the library,and design the data transmission program to solve the problem of data conflict and congestion in this process.Finally,the local data management software and the monitoring,query and early warning interface of the cold storage management system are designed to manage the cold storage data.Due to the large number of monitoring equipment deployed in the cold storage of agricultural products,the system pays special attention to low cost and low power consumption to ensure the practicability of the system.Finally,the temperature and humidity monitoring system of this study is tested.After testing,the system can realize the functions of multi-node temperature and humidity monitoring in the cold storage,real-time uploading of cold storage data to the network and centralized monitoring and management of cold storage information.The system can monitor the cold chain storage data of agricultural products stably and with low energy consumption at the set time interval.The data accuracy is high,and the system equipment can last for a long time.