| 摘要 |
PROBLEM TO BE SOLVED: To provide a wireless tag positioning system that can determine a two-dimensional coordinate of a wireless tag with excellent accuracy.SOLUTION: A movement distance in a radial direction (a measurement distance Dm) serving as a distance in which a wireless tag 200 moves in the radial direction of a wireless tag reader 100 is measured (S2). With respect to a combination of points before and after a movement serving as a combination of an area vertex generated by dividing a positioning area into a plurality of small areas, a movement distance in the radial direction (=a computation distance Dc) is computed, and a distance difference e between the measurement distance Dm and the computation distance Dc is sequentially calculated with respect to all combinations of the points before and after the movement for each of four wireless tag readers 100 (S4). A candidate of the point before and after the movement in which the distance difference e falls within an error range is narrowed down (S6). Further, as to a continuous movement by two times, a combination of the point before and after the movement in which a point after a previous movement and a point before a later movement coincide with each other is narrowed down. The narrowing-down is performed to each movement in order until a latest movement from a movement before a past preliminary set predetermined time. |
