Localização 3D em sistemas RFID com leitor móvel

Abstract

In this work we adopt an matrix of real reference tags (passive) and virtual tags (tags that do not exist physically). We use a single mobile RFID reader, in order to reduce the implementation costs. The mobility of the reader allows it to move in all directions and to be able to read in different positions. At the end of the readings the proposed algorithm evaluates the difference between the RSSI of the target tag and the RSSI of the reference matrix tags, looking for similarities between their values, returning possible positions of the target tag (tags positions of the reference matrix wich has the RSSI with a difference value between zero to "x" dB when compared to RSSI of the target tag). Then the algorithm evaluates the difference between the coordinates x, y, and z of the possible positions, identifying which axis has the largest difference. After that perform a new reading by moving the reader on the axis of greatest difference. The position of the reference tag with the RSSI closest to the RSSI of the target tag in this new reading is selected as the position estimated by the system. Experiments using the simulated environment demonstrated that the proposal was more accurate when compared to other studies (gain of 46% comparing the Error of the proposed solution with the Error of other solutions).