Current position calculating device
US5941934A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 7, 1996 |
| Grant date | Aug 24, 1999 |
| Priority date | — |
| Expiry date | Jun 7, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C21/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A microprocessor 24 detects turn start and turn finish of a vehicle on the basis of outputs of various sensors 11, 12 and 13, and during this operation, the microprocessor 24 successively sets a current position to a middle point of a next link every time a predetermined condition is satisfied. While the current position is shifted from the middle point of a link to the middle point of a next link, the vehicle travel azimuth output from the sensor is corrected to approach to the azimuth of the link by an amount corresponding to the difference between the link azimuth of the just-previous middle point and the vehicle travel azimuth, and the current position is displayed on the basis of the corrected travel azimuth and the travel distance. Information on each link is obtained form a road map which is stored in a CD-ROM 15 and in which roads are expressed by an assembly of links. With this device, the current position can be displayed in the vicinity of a road on a road map on which the vehicle runs, even on a curve which is not accurately displayed on the road map.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.