| 摘要 |
PROBLEM TO BE SOLVED: To provide a "current position calculator" capable of calculating properly a current position, after the lapse of a period not allowing measurement by radio navigation. SOLUTION: This calculator calculates a position moved by the lapse of time from the n-th time to the n+m-th time of this time, at a speed found as an average of a moving speed Vn found at the n-th time by a GPS receiver 4 and a moving speed Vn+m found by the GPS receiver 4 at the n+m-th time, along a direction found as an average of a moving directionθ1 found at the n-th time by the GPS receiver 4 and a moving directionθ2 found at the n+m-th time by the GPS receiver 4, based on the present position Fn output at the n-th time when a positioning data is acquired from the GPS receiver 4 in the last before the last time, and a prediction range Bn+m is set in the periphery thereof. A positioning position found by the GPS receiver 4 at this time is output as the current position when the positioning position is included within the prediction range, and a predicted position is output as the current position when not so. COPYRIGHT: (C)2007,JPO&INPIT |
