Vehicle position calculation apparatus and method

• US 6,581,005 B2
• Filed: 11/14/2001
• Issued: 06/17/2003
• Est. Priority Date: 11/30/2000
• Status: Expired due to Fees

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Saitou, Hiroshi, Minakawa, Rumi, Watanabe, Masaki, Nakayama, Okihiko
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): To, Tuan C
• Application Number:
  US09/987,274
• Publication Number:
  US 20020065603A1
• Time in Patent Office: 580 Days
• Field of Search: 701/207, 701/208, 701/209, 701/210, 701/211, 701/217, 701/117, 701/102, 701/200, 701/212, 340/990, 340/995, 340/988, 344/988, 702/150, 702/94, 702/95
• US Class Current: 701/210
• CPC Class Codes: G01C 21/30 Map- or contour-matching

Abstract

A vehicle position calculation apparatus and method are provided to correct a vehicle position to be located on a map route. The vehicle position calculation apparatus has a vehicle position measuring section measuring a vehicle position, a road data supply section supplying road geometrical data including a line segment and a closed region correlated with a road on a map, and a vehicle position correcting section correcting the vehicle position on the map by using the road geometrical data. The position correcting section locates the vehicle position by itself on the map as a corrected vehicle position, in response to a relatively positional relation between the vehicle position and the road geometrical data. In such a correction, the vehicle position correcting section can correct the vehicle position to be in alignment with a point on corresponding one of position correction shapes, or it can correct the vehicle position onto a traveling link generated in response to the road geometrical data.

Claims

1. A vehicle position calculation apparatus comprising:

a vehicle position measuring section measuring a vehicle position;

a position correcting shape memory section storing road shape data including position correction shapes composed of a group of line segments representing a center of a road and a two-dimensional closed regional shape correlated with a predetermined location on a map; and

a vehicle position correcting section correcting the vehicle position on the map to be in alignment with a point on corresponding one of the position correction shapes stored in the position correcting shape memory section,

wherein the vehicle position correcting section includes;

a correction reference determination unit determining whether to correct the vehicle position based on a reference of any one of the position correcting shapes stored in the position correcting shape memory section, on the basis of a close proximity or inclusive relationship between the vehicle position and the any one of the position correcting shapes;

a line segment conformity position correcting unit correcting the vehicle position so as to allow the vehicle position to be aligned onto a point of the line segment which the correction reference determination unit determines as the reference; and

a regional conformity position correcting unit correcting the vehicle position so as to allow the vehicle position to be aligned onto a point inside the closed regional shape or on a point of a contoured line segment of the closed regional shape which the correction reference determination unit determines as the reference.

2. A vehicle position calculation apparatus according to claim 1, wherein when a corrected value, which is corrected at a given time instant, of the vehicle position lies inside the closed regional shape, which the correction reference determination unit determines as the reference, or lies on a contoured line segment thereof and when a measured value, which is obtained at a subsequent given time instant, of the vehicle position remains outside the closed regional shape, the correction reference determination unit determines to use the line segment as the reference for correction of the vehicle position on the basis of a close proximity relationship between enter and exit line segments correlated with the closed regional shape and the vehicle position.

3. A vehicle position calculation apparatus according to claim 2, wherein the correction reference determination unit determines to use the closed regional shape as the reference for correcting the vehicle position when none of the enter and exit line segments remains in the vicinity of the vehicle position.

4. A vehicle position calculation apparatus according to claim 1, wherein the position correcting shape memory section stores the position correcting shapes to include the closed regional shape composed of an outer shape of a road with respect to a vicinity of nodes in which more than three roads connect with each other as a connection area.

5. A vehicle position calculation apparatus according to claim 1, wherein the position correcting shape memory section stores the position correcting shapes to include the closed regional shape composed of an outer shape of a sinuous road with a large radius of curvature.

6. A vehicle position calculation apparatus according to claim 1, wherein the position correcting shape memory section stores the position correcting shapes to include an outer shape of a large area facility to which a vehicle is able to enter or an outer shape representing a vehicle traversable range of the large area facility, and line segments which interconnects the outer shape of the large area facility or that representing the vehicle traversable range and existing road segments.

7. A vehicle position calculation apparatus according to claim 1, wherein the vehicle position correcting section includes a measured value reliability determination unit which determines a degree of reliability of a measured value of the vehicle position outputted from the vehicle position measuring section.

8. A vehicle position calculation apparatus according to claim 7, wherein the correction reference determination unit determines to correct the vehicle position based on a reference of the line segment regardless of the closed regional shape when the degree of reliability determined by the measured value reliability determination unit is below a predetermined level.

9. A vehicle position calculation apparatus according to claim 7, wherein the measured value reliability determination unit evaluates degrees of a plurality of reliabilities to select a most reliable measured value of the vehicle position as an object to be corrected.

10. A vehicle position calculation apparatus comprising:

a vehicle position measuring section measuring position information representing a vehicle position and bearing information representing a vehicle travel direction;

a road map memory section storing road shape data composed of polygons correlated with a road on a map;

an attribute data memory section storing joint attribute data representing traffic regulating information with respect to the road shape data and a joint state information between the road shape data;

a map read out section reading out the road shape data in a vicinity of the vehicle position and the joint attribute data from the map read out memory section and the attribute data memory section, respectively, on the basis of the position information;

a traveling link generating unit generating a traveling link correlated with the vehicle position in response to the road shape data and the joint attribute data read out by the map read out section, on the basis of the position information and the bearing information; and

a vehicle position correcting section responsive to the position information and the bearing information to correct the vehicle position on the map onto the traveling link generated by the traveling link generating unit.

11. A vehicle position calculation apparatus according to claim 10, wherein the traveling link generating unit extracts the number of traffic lanes from the road shape data read out by the map read out section and generates the traveling link correlated with the vehicle position by using the number of traffic lanes.

12. A vehicle position calculation apparatus according to claim 10, further comprising a traffic lane number information memory section storing traffic lane number information of the road,

wherein the map read out section reads out the traffic lane number information of a region in the vicinity of the vehicle position from the traffic lane number information memory section on the basis of the position information,

and wherein the traveling link generating unit generates the traveling link by using the traffic lane number information read out by the map read out section.

13. A vehicle position calculation apparatus according to claim 10, further comprising a traffic route searching section conducting a search for a traffic route to a destination,

wherein the traveling link generating unit generates the traveling link associated with the traffic route searched by the traffic route searching section.

14. A vehicle position calculation apparatus according to claim 10, wherein the traveling link generating unit stores the traveling link generated by the traveling link generating unit.