Data processing: vehicles – navigation – and relative location – Navigation – Employing position determining equipment
Patent
1996-11-05
1999-12-14
Chin, Gary
Data processing: vehicles, navigation, and relative location
Navigation
Employing position determining equipment
701200, 701209, 340990, 340995, G06F16500
Patent
active
060029811
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to a method for correcting composite-navigation and to a navigation system of a motor vehicle.
BACKGROUND INFORMATION
When working with a map-supported navigation system, conventional systems are used to determine position using a composite-navigation process in which the data supplied by the sensors of a motor vehicle are compared to those of a digital road map. The vehicle position determined by the composite-navigation process is corrected, the vehicle being placed on a street that runs nearby. However, if many streets run at a similar angle relative to the travel direction of the vehicle, it is possible that the vehicle may be positioned on the wrong street. As it continues its trip, the vehicle remains on this "incorrect street", since no other test is performed to check the accuracy of this positional correction.
European Patent Application No. 0 314 806 describes that a range of error is determined for the estimated vehicle position, whose magnitude is predetermined by the tolerances of the sensors for the length of travel and the driving direction. By means of a computer, those vehicle positions, which are transmitted for a given driving situation, are calculated for all streets within the range of error. By estimating the distances and other parameters, the vehicle position whose street characteristic curve comes the closest is determined to be the actual position. In this conventional method, the problem arises that when working with a narrow network of streets having several parallel routes situated closely together, the street can not always be found on which the vehicle is actually driving.
SUMMARY OF THE INVENTION
One of the advantages of the correction method and the navigation system according to the present invention is that several possible vehicle positions are calculated concurrently, all travel routes within a driving area being considered. Even when a main route is found for the most probable vehicle position, it is retained only until a parallel route reaches a greater level of probability for the vehicle position on the basis of plausibility considerations. This yields the advantage that the navigation vehicle guidance) becomes more reliable, and the vehicle is always localized on the street where it is actually located.
It is also advantageous to include the measuring tolerances of the sensors and/or of the navigation device, so that the range of error is always calculated (or estimated) to ensure that the vehicle is situated within the ranges of error. This ensures that the potential vehicle locations are determined for all streets in the driving area.
It is also beneficial to select a street as the main route whose direction substantially conforms with that of the composite navigation travel route and which is the closest to the route. If the main route is selected again when additional measurements are taken, for example, also in view of the life span of the route or its angle of inclination, then it is highly probable that it corresponds to the actual travel path of the vehicle.
To avoid vacillating back and forth to determine the most likely vehicle position (main route position), for example, when streets run in parallel and at a small distance from one another in sections, an evaluation (qualification) hysteresis is provided, so that the main route is not changed until several measurements have proven such a change to be plausible.
When the length of the travel path is measured, sensor-related errors occur, which can then be simply recognized when the vehicle travels out or turns off at an intersection. Since the position of the intersection is determined by its exact coordinates, a reference point is thus obtained between two measuring marks, which can be used to correct the length measurement.
Since the position of the vehicle can also be determined using navigation satellites, the simplest way to eliminate errors occurring transversely to the driving direction (route and direction) is to mathematically place the
REFERENCES:
patent: 4796191 (1989-01-01), Honey et al.
patent: 4807127 (1989-02-01), Tenmoku et al.
patent: 4964052 (1990-10-01), Ohe
patent: 4999783 (1991-03-01), Tenmoku et al.
patent: 5307278 (1994-04-01), Hermans et al.
patent: 5359529 (1994-10-01), Snider
patent: 5374933 (1994-12-01), Kao
patent: 5523765 (1996-06-01), Ichikawa
patent: 5583775 (1996-12-01), Nobe et al.
Patent Abstracts of Japan, vol.13, No. 382, Aug. 24, 1989.
Chin Gary
Robert & Bosch GmbH
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