| With the rapid development of our economy, people’s living standard has been improved gradually and there are also higher requirements for food quality. Food quality is not only required to be safe, but its characteristics are also demanded to be almost perceptual. But for plant food, animal food and artificial food, during raw materials removal, processing, logistics, warehousing, sales and other sectors, their water activity (AW), Total acidity, nutrients, natural microorganisms, enzymes, biochemical substrates and preservatives and other factors, will be affected by outside temperature, humidity, light and environmental microorganisms and the composition of the packaging gas. And these important factors go through physics, chemistry and microbiology change, suffer gradual loss of its original quality at a certain speed,in some manner. So many links such as food production, transport and sales need to be monitored to make sure of food quality. However, the traditional methods simply set food production date and make use of bar code technology for food security and distribution management, which can’t satisfy the more intensive and highly effective purpose of food safety management.In view of the problems above, this paper uses RFID to design the RFID shelf‐life indicator. RFID shelf‐life indicator consists of smart RFID reader and RFID mode.It can complete optical‐invisibly and non‐contact identification work. RFID shelf‐life indicator is also able to collect and store food quality data during the whole circulation process, identify long‐distance and high‐speed food to improve the processing speed of traditional goods sorting and registration information, and reduce human errors.Smart RFID mode faces lots of problems when monitors and accesses food real‐timely. Especially in refrigerating transportation process, smart RFID mode has typical industry characteristics. Firstly，mode works under harsh environment such as low temperature, wet, mechanical vibration shock, big metal interference and electromagnetic interference, etc. Secondly, RF device requires long‐distance recognition, achieving multi‐targets with fast identification. Finally, it also needs low power consumption, large data capacity and long service life. All of these propose higher demand for RFID shelf life indicator.This paper focuses on power consumption and anti‐collision of RFID shelf‐life indicator.This paper analyzes power sources of smart RFID mode, then divides its function modes, and realizes the dynamic power management by Time Series Power Management Algorithm, which reflects its high energy efficiency compared with power consumption based on Timeout Algorithm. The smart RFID mode consumes more energy during communications process, meanwhile probably comes out reading leakage because of multi‐modes information collision in the communication. This paper designs smart self‐adaptive frame slot ALOHA algorithm to solve the energy and collision problem of smart RFID mode.Based on the above research, this paper designs the RFID shelf life indicator software and relevant hardware circuit. and three sets of experiments are made to test the devices performance. First, this paper measures its communication distance to verify whether it satisfies the long‐distance communication, to ensure that it can be applied properly in the cold chain logistics process. Secondly, numbers of moving modes are tested to validate reading leakage. Finally, we concern the power consumption of intelligent RFID particles by Time‐series algorithm and self‐adaptive frame slot ALOHA algorithm. The results show that the RFID shelf life indicator can satisfy the requirements of long‐distance communication; a number of mobile smart RFID modes can be recognized by smart RFID reader; and intelligent RFID modes can meet demands for low power consumption in the cold chain logistics process. Finally, we make a conclusion on the completed work and propose the existing problems in the field. |
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