Terminal device and guidance program
US9347781B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 2013 |
| Grant date | May 24, 2016 |
| Priority date | — |
| Expiry date | Mar 15, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09B29/106
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A navigation device includes a GPS receiver, map data including tunnel data and periodically acquires a vehicle's speed to provide guidance on the current position N acquired at the GPS receiver, and when GPS radio waves become unreceivable after the vehicle passes a tunnel entrance, calculates a travel distance according to a vehicle speed and a time T up to a branch, and continues providing guidance on the current position up to the branch. After passing the branch, the navigation device suspends guidance, calculates a distance La between the branch and a tunnel exit, which is shorter, and when GPS radio waves are not received even after a movement distance from the branch exceeds distance La, after passing the branch, determines a road whose distance is longer as the road being traveled, and provides guidance on the current position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.