An active LF RFID positioning method against metal interference

Aiming to solve the problem that multi-beacon received signal strength indicator (RSSI) ranging system is easily interfered by metal objects, this paper proposes a method to locate the cooperative target based on probability distribution. This method first calculates the probability of the source at each point within the beacon sensing range and then obtains the location by searching the coordinates of the point with the highest probability in the area. Experiments have proven that, compared with the traditional maximum likelihood positioning algorithm, this algorithm shows better performance in resisting metal interference. The positioning error of the proposed method is within 3cm, showing its priority against metal interference.