Passive Rfid Positioning And System Research

.With the rapid development of modern electronic technique and communication technology, people are in great need for real time information. Accurate, reliable and real-time location information is of utmost importance for navigating, tracking and monitoring, which leads to more and more researches on location method.Ultra High Frequency (UHF) Radio Frequency Identification (RFID) is a burgeoning automatic identification technology. Due to its long work range, non-visual environment and large information capacity. Real Time Location System (RTLS) based in RFID has become a research focus in industry. However, for applications in real world, it is quite difficult to implement a low cost, low power and long range location system.Dual frequency phase comparison theory in traditional radar technology is introduced into the RFID system in this dissertation. The theory is analyzed in detail with the consideration of signal transmission features in RFID. System based on the theory is designed and simulation model is built. Hardware implementation has also been completed to verify the performance of the system.Firstly, the dissertation gives a survey of navigation and location techniques, compares their applications and merits and demerits. Secondly, how the dual frequency phase comparison theory can be applied in RFID systems is introduced specifically. Non-ideal factors of the system have some influence on the performance, which is also analyzed and tolerant values the factors is given within the target accuracy. Thirdly, system model is built and simulated in Matlab/Simulink to verify the function. Finally, NI modularization instrument testing platform is introduced, based on which the system is implemented. Measured results indicate that the wire location average accuracy is lcm, and wireless accuracy5cm, which prove the correctness and reliability of the proposed system.