Design And Implementation Of Indoor Localization Hardware Platform Based On Active Radio Frequency Identification

Internet of Things connects objects through the Internet. In the world of Internet of Things, the occurrences of any event are highly correlated with its physical location. Data without physical location is incomplete. GPS, the most important location information service system, also has some limitations, which can not provide location sensing service in indoor environments. As the development of Internet of Things, the research of the indoor location sensing systems based on RFID, Image Processing, Infrared, Laser, ultrasonic wave attract lots of attention in recent years. Among others, RFID provides an excellent approach with its advantages of non line of sights, high precision, low cost and simple configuration.Currently, most indoor location systems are based on passive RFID technology and LANDMARC algorithm. However, these passive RFID hardware platform have some disadvantages, such as short communication distance, communication protocol redundant, and LANDMARC algorithm has high positioning latency and high system cost problems, which lead to the problem of low positioning accuracy, high positioning latency and low efficiency of multi-tag anti-collision occur in these indoor location systems. The aim of this paper is to design an active RFID indoor location hardware platform based on the analysis above, the major work of this paper specifically stated as follows:(1) Aimed at the short communication distance and lower efficiency of multi-tag anti-collision problem existing in passive RFID hardware platform, this paper design an active RFID hardware platform working in the 2.4GHz, having a longer communication distance and a higher efficiency of multi-tag anti-collision. The main work includes hardware design, circuit design, PCB design and hardware debug.(2) Aimed at the communication protocol redundant problem existing in passive RFID hardware platform, this paper design a communication protocol for the platform, which simplifies the communication flow between indoor location devices, reduces communication latency, improves communication efficiency.(3) Aimed at the high positioning latency and high system cost problems existing in LANDMARC algorithm, this paper design a RSSI and Trilateration based indoor location algorithm, which can reduce positioning time delay and system cost without any positioning accuracy reduction. The main work includes developing an indoor location PC software based on the algorithm design.According to the actual test results, this indoor location hardware platform based on active RFID had achieved better performance on the reading distance, multi-tag anti-collision and positioning time delay, when comparing to the passive RFID hardware platform. This platform can be used in warehouses, psychiatric hospitals and other indoor positioning applications for people or valuables.