Data processing: vehicles – navigation – and relative location – Navigation – Employing position determining equipment
Reexamination Certificate
1998-07-07
2001-03-06
Cuchlinksi, Jr., William A. (Department: 3661)
Data processing: vehicles, navigation, and relative location
Navigation
Employing position determining equipment
C701S207000, C701S209000, C701S210000, C701S212000, C701S214000, C340S988000, C340S990000
Reexamination Certificate
active
06199011
ABSTRACT:
DETAILED DESCRIPTION OF THE INVENTION
1. Field of the Invention
The present invention relates to a navigation system including a map information storing means having road data stored therein, and a subject-vehicle position detecting means for detecting the position of a subject vehicle on a map, and to a vehicle control system using the navigation system.
2. Background of the Invention
Road data used in a navigation system is formed of a large number of nodes established at predetermined distances on a road. The road data is previously stored in a storage medium such as a CD-ROM or the like. When a radius of curvature of a curved road is calculated based on such road data, it is common to use a technique for determining a radius of an arc of a circle passing through three continuous nodes. Therefore, if there is no error in the coordinates of the three nodes N
1
, N
2
and N
3
, which are established at an inlet position, a central position and an outlet position of a curved road, as shown in
FIG. 4
, the radius of curvature of the curved road which is calculated from the coordinates of the three nodes N
1
, N
2
and N
3
is R.
However, if the node N
2
which is established, for example, at the central position of the curved road, is offset to a radially outer position (a position N
2
′), the radius of curvature of the curved road calculated from the coordinates of the three nodes N
1
, N
2
′ and N
3
is R′ and smaller than the correct radius R of curvature, resulting in the generation of an error.
When the position of the road has been changed due to repair work, or when a road has been newly constructed, it is impossible to cope with these situations in a conventional navigation system, because there is no road data for such a road in a storage medium.
SUMMARY OF THE INVENTION
The present invention has been accomplished with the above circumstance in mind. It is therefore an object of the present invention to provide a navigation system which can compensate for any errors in the road data and/or omission of the road data, and to provide a vehicle control system using the navigation system.
To achieve the above object, according to a first aspect and feature of the present invention, there is provided a navigation system comprising a map information storing means having road data stored therein. A subject-vehicle position detecting means detects the position of a subject vehicle on a map. The navigation system further includes an azimuth angle-varied state detecting means which detects the azimuth angle-varied state of the subject vehicle. A road data correcting means corrects the road data stored in the map information storing means based on the azimuth angle-varied state and the position of the subject vehicle.
With the above arrangement, the error of the road data corresponding to an inlet position, a central position and an outlet position of a curved road or a branch road can be accurately corrected based on the azimuth angle-varied state of the subject vehicle and the position of the subject vehicle at that time. The correcting of the road data includes newly establishing omitted road data.
According to a second aspect and feature of the present invention, in addition to the first feature, the azimuth angle-varied state detecting means detects at least one of an inlet position, a central position and an outlet position of a curved road based on the detected azimuth angle-varied state.
With the above arrangement, it is possible to detect the inlet position, the central position and the outlet position of the curved road which are important for determining the shape of the curved road.
According to another aspect and feature of the present invention, in addition to the second aspect, the azimuth angle-varied state detecting means detects a yaw rate generation starting position of the subject vehicle as the inlet position of the curved road.
With the above arrangement, the inlet position of the curved road can be accurately detected.
According to another aspect and feature of the present invention, in addition to the second aspect, the azimuth angle-varied state detecting means detects a yaw rate generation finishing position of the subject vehicle as the outlet position of the curved road.
With the arrangement, the outlet position of the curved road can be accurately detected.
According to a further aspect and feature of the present invention, in addition to the second aspect, the azimuth angle-varied state detecting means detects a yaw rate peak position of the subject vehicle as the central position of the curved road.
With the arrangement, the central position of the curved road can be accurately detected.
According to another aspect and feature of the present invention, in addition to the first aspect, the azimuth angle-varied state detecting means detects at least one of an inlet position, a central position and an outlet position of a branch road based on the detected azimuth angle-varied state.
With the above arrangement, it is possible to detect the inlet position, the central position and the outlet position of the curved road which are important for determining the shape of the branch road.
According to another aspect and feature of the present invention, in addition to the above aspect, the azimuth angle-varied state detecting means detects a yaw rate generation starting position of the subject vehicle as the inlet position of the branch road.
With the above arrangement, the inlet position of the branch road can be accurately detected.
According to a further aspect and feature of the present invention, in addition to the above aspect, the azimuth angle-varied state detecting means detects a yaw rate generation finishing position of the subject vehicle as the outlet position of the branch road.
With the above arrangement, the outlet position of the branch road can be accurately detected.
According to another aspect and feature of the present invention, in addition to the above aspect, the azimuth angle-varied state detecting means detects a yaw rate peak position of the subject vehicle as the central position of the branch road.
With the above arrangement, the central position of the branch road can be accurately detected.
According to a further aspect and feature of the present invention, there is provided a vehicle control system including a navigation system according to any of the above aspects, comprising an ahead-road shape determining means for determining the shape of a road ahead of the subject vehicle based on the road data resulting from the correction by the road data correcting means, an appropriate passage speed calculating means for calculating an appropriate passage speed on the road ahead of the subject vehicle determined by the ahead-road shape determining means, and a vehicle control means for carrying out the vehicle control based on a vehicle speed of the subject vehicle and the appropriate passage speed calculated by the appropriate passage speed calculating means.
With the above arrangement, the shape of the road ahead of the subject vehicle is determined based on the corrected road data, and the vehicle control is carried out based on a determined appropriate passage speed of the road ahead of the subject vehicle and a vehicle speed of the subject vehicle. Therefore, it is possible to properly carry out the vehicle control for permitting the subject vehicle to safely pass through the road ahead of the subject vehicle. The vehicle control includes a warning to a driver, in addition to an automatic decelerating control and a steering operation assisting control for permitting the vehicle to pass through the curved road.
REFERENCES:
patent: 5383127 (1995-01-01), Shibata
patent: 5469360 (1995-11-01), Ihara et al.
patent: 5512904 (1996-04-01), Bennett
patent: 5884218 (1999-03-01), Nimura et al.
Arent Fox Kintner & Plotkin & Kahn, PLLC
Arthur Gertrude
Cuchlinksi, Jr. William A.
Honda Giken Kogyo Kabushiki Kaisha
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