| 摘要 |
PURPOSE:To detect the position of a cart even if it is difficult to receive a radio wave from a GPS satellite. CONSTITUTION:Plural position correcting means are installed on a cart way with different installation patterns and the positions of the respective position correcting means are previously stored in a storage part 5; if it becomes impossible to receive the radio wave from the GPS satellite, a detecting means 3 detects the position correcting means on the cart way, reads the installation positions of the detected position correcting means out of the storage part 5, and decides the installation position which is the closest to the last display position before the reception is disabled as the present position of the cart among the installation positions. Therefore, even if the radio wave from the GPS satellite can not be received, the position of the card can be detected. |
