| 摘要 |
PROBLEM TO BE SOLVED: To improve position estimation accuracy of a position detecting device, which is carried by a user or installed on vehicles, and utilizes GPS to check the current position, when measurement is impossible. SOLUTION: When position information of each of the positions P1 to P4 corresponding to times t1 to t4 is obtained from GPS, the position detecting device adopts the information and stores it. If measurement is impossible at a time t5, the device obtains position information of a position P0 of a base station for cell phones and information of a communication area A0, however, does not adopt the position P0 of the base station as the current position. Based on the previous histories, the device estimates a position PO5, and determine whether the position P4 is within the area A0. Since the communication with the base station is available, the position PO5 is adopted as the current position P5. The same procedures are used at a time t6. At a time t7, although a predicted position PO7 is not included in the area A0, if the communication with the base station is available, the position P0 of the base station is adopted as the current position for the first time. COPYRIGHT: (C)2006,JPO&NCIPI |
