Estimating the direction of motion based on active RFID

RFID is one of the crucial technology of the IOT (Internet of things), and it has been applying to the fields of manufacturing, logistics management, public security, etc. Active RFID, as one important component of RFID, has striking features of low power consumption, stable signals, long-range read and strong anti-jamming ability. Active RFID is thus widely used in the areas of long-range identification of people and vehicles and Real Time Location System. In the various applications of active RFID, estimating the direction of motion is a vital technical issue. This paper puts forward a new method to estimate. In other words, using several directional antennae, it forms several reading zones, extracts events of tag-entering or tag-leaving and then realizes the estimation by the order of events. In this way, it is feasible to estimate not only the direction of motion of tags accurately, but also other complicated logic, e.g. tag return midway.