| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the detection accuracy of position information by estimating the position information, based upon service information in the neighborhood of the position information when the position information cannot be detected normally. SOLUTION: When position information from a GPS cannot be detected (S10), service information is being detected (S11, S12) until the position information is detected, and estimated value of the position information is calculated (S14), based upon detected service information and the latest service information stored (proximate service information). Then, estimated position information and detected time and vehicle velocity are stored into a memory device (S15). Meanwhile, when position information can be detected from the GPS (S10), detected position information, time and vehicle velocity are stored in a storage device (S16). Also, then the service information is a first data, estimated value of the position information is calculated, based upon two pieces of service information continuously detected.</p> |
