In the past two years, IoT concepts such as "Smart Earth" and "Sensing China" have emerged one after another, and concepts such as "sensor network" and "M2M" have also received unprecedented attention. Different concepts are amplified by different differences in different application fields, and the core of technical implementation is to emphasize the automatic collection of information, ubiquitous ubiquitous convergence network and intelligent identification, management and control.
Although the Internet of Things is considered to be the third wave of information industry after computers, the Internet and mobile communication networks, the lack of "industry application" will be the biggest problem in its development. Only through large-scale industry application can the Internet of Things promote the formation of the industry, the breakthrough and standardization of core and key technologies.
Combined with food safety and logistics informatization, the establishment of a modern food logistics system based on the Internet of Things can be aimed at the circulation of fruits and vegetables, aquatic products, and poultry preparation, and the implementation of safety detection, control, monitoring, traceability, information sharing, etc., which has great practical significance, economic and social benefits.
The modern food logistics system will record the whole process of the effective flow of raw materials and finished products from the starting point to the end of demand and related information, and modularize procurement, transportation, warehousing, loading and unloading, circulation processing, distribution and other links. By analyzing the relationship between each module, the network relationship diagram of the first link is formed. The modules are digitized and turned into a database that can provide data.
The modern food logistics information technology system is mainly composed of the basic layer, the support layer, the data layer, the business layer, the application layer, the main technologies of the application include short-range wireless communication (NFC), mobile communication technology, global satellite positioning (GPS) technology, geographic information (GIS) technology, computer network technology, multi-technology technology, automated warehouse management technology, information exchange technology, database, Web technology, etc.
As mentioned above, the modern food logistics system covers almost all aspects of communication technology, and in terms of application scale and technical difficulty, the key technologies mainly include sensing technology and wireless communication.
The automatic collection of information depends on the sensor to complete, how to convert the changes in the food environment such as temperature, humidity, pressure, brightness and other food environment into data sources, which can be collected and processed, is the first problem to be solved by the modern food logistics system. The technology of the sensor itself is relatively perfect, and it can feedback almost any information that needs to be perceived. IoT fields such as food logistics require further sensing technology, where sensors need to be miniaturized and embedded in any environment and object where information needs to be collected, especially suitable for system-on-chip (SoC) integration. Another benefit of miniaturization is cheapness, as a large number of sensors are required for large amounts of data acquisition, and low-cost sensors make the construction of the entire network more realistic.
Wireless communication technology and sensing technology are combined to form a wireless sensor network, and the Internet of Things is also called a sensor network, which is due to this. The basic function of a node in the network is to transform and process the information collected by the sensor, and then use wireless communication technology to transmit the data, so the node composition can be basically divided into three parts: sensing unit, processing unit, and radio frequency unit.
Wireless communication can be divided into two parts: short-range wireless communication and long-distance wireless communication, short-range wireless communication can form a local local area network, and long-distance wireless communication can be connected to the Internet and other public networks to form a wide area network.
Although the unified interface specification of the Internet of Things is still being formulated, there are already some mature industry standards for use, and the current standards that can be used for short-range wireless communication are RFID, Zigbee, WiFi, etc., which can easily form a wireless sensor network with sensors. The scale configuration of the wireless sensor network is relatively flexible, and a minimum local area network can complete the collection of one or several kinds of information required in a certain area, and a plurality of such local networks can complete the collection and processing of various information in the entire required monitoring area.
The local LAN function range of a wireless sensor network can be limited, can not track the entire link of food logistics, and can not effectively perceive and cover a wide range of discontinuous areas, only by relying on long-distance communication technology to form a wide area network, can the entire logistics system be fully detected. The long-distance wireless communication network also has ready-made technology and mature network, using GPRS, EVDO, TD-SCDMA and other public networks, without setting up a new network, you can effectively complete the exchange of information.
The wireless perception network of the whole food logistics system includes a flat network architecture and a hierarchical network architecture, and a variety of network architectures are mainly used to meet the different networking and management requirements. Among them, the flat architecture is more suitable for a local network, and the layered network architecture is more suitable for a wide area network.
Sensors cannot locate their own location and need to be combined with positioning technology and electronic maps to complete the information in the food logistics system. The combination of GPS, GSM, CDMA and other mobile communication technologies helps logistics systems to obtain geolocation information more quickly and accurately.
Source: Communications & Information Technology.
Original title: Modern food logistics system based on the Internet of Things.
Author: Zhang Jiakun, Xing Baozhen.