Exploratory study of RFID applications for air cargo operations .

摘要

The air cargo system is a complex network that handles a vast amount of freight aboard passenger and all-cargo aircraft. With today's globalization, there is a growing need for fresh products to be delivered year round all over the world, thus, temperature sensitive items are likely to be shipped by air because of their relatively short shelf life. Moreover, increasing demand for just in time delivery; containers being packed by third parties; inspection time being very limited and transportation security being linked to volume, monitoring of goods within containers as well as within the cargo warehouse may contribute to enhanced security, operation efficiency and provide valuable real-time information. New technologies to better track cargo shipments are accountable for maintaining control and tracking along the supply chain. Radio frequency identification (RFID) is seen as an emerging technology for improving the air cargo supply chain.;For RFID technology to be implemented, more research has to be done regarding the environmental compatibility of air cargo warehouses, the regulations involved and the materials encountered in this supply chain. Moreover, the frequency of choice may be critical for system optimization. Therefore, the main objectives of this dissertation are: indentify the multiple RF interferences encountered inside an air cargo warehouse; evaluate the RF propagation behavior inside the cargo hold of an aircraft at different frequencies; verify the effect of container wall materials on RF propagation; study the temperature distribution of different cargo holds during flight.;The main findings of this research are that interferences are lowest at 915MHz inside the air cargo warehouses studied. Following the same direction, RF propagation inside the cargo hold was found to be best at 915MHz when taking into account federal spectrum regulations. In addition, the container materials experiment showed a very strong effect of aluminum on RF transmission and minimal interaction for all other composite materials. Moreover, there can be a significant temperature gradient between the top and bottom of air cargo containers during ground operations as well as during flights. The global system proposed from this research states that a combination of active and passive tags at 915MHz could create a well suited structure for tracking of the air cargo supply chain. To summarize, the findings of this dissertation suggest that using 915MHz RFID systems for air cargo operations would lead to the most success and system flexibility considering warehouse interference, cargo hold RF propagation, temperature monitoring needs and types of tag technology available today.