CURVE-SHAPE MODELING DEVICE, VEHICLE INFORMATION PROCESSING SYSTEM, CURVE-SHAPE MODELING METHOD, AND NON-TRANSITORY TANGIBLE COMPUTER READABLE MEDIUM FOR THE SAME

• US 20160054133A1
• Filed: 03/21/2014
• Published: 02/25/2016
• Est. Priority Date: 04/19/2013
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: MIZUNO, Nobuhiro, IIDA, Masahiro
• Granted Patent: US 9,885,578 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01C 21/3811 Point data, e.g. Point of Interest [POI]
• CPC Class Codes: G01C 21/3819 Road shape data, e.g. outline of a route
• CPC Class Codes: G09B 29/00 Maps; Plans; Charts; Diagrams, e.g. route diagram star maps G09B27/04; devices for holding or supporting maps A47B97/02; for computing purposes G06G1/14, G09B1/16; display boards G09F

Abstract

A curve-shape modeling device that divides multiple sampling points along a route into a linear section, a relaxation curve section and a steady section, and models a curve shape of the route, includes: a curve extraction unit that extracts a curve from the sampling points based on a curvature of the sampling points; a steady section curvature determination unit that determines a curvature of the steady section based on a curvature of sampling points included in an extracted curve; and a curve entry and exit determination unit that sets a predetermined curvature range including the curvature of the steady section, and determines a start point and an end point of the steady section based on the curvature range.

Claims

1. A curve-shape modeling device that divides a plurality of sampling points acquired along a route into a linear section, a relaxation curve section and a steady section, and models a curve shape of the route, the curve-shape modeling device comprising:

a curve extraction unit that extracts a curve from the sampling points based on a curvature of the sampling points;

a steady section curvature determination unit that determines a curvature of the steady section based on a curvature of sampling points included in the curve extracted by the curve extraction unit; and

a curve entry and exit determination unit that sets a predetermined curvature range including the curvature of the steady section, and determines a start point and an end point of the steady section based on the curvature range.

2. The curve-shape modeling device according to claim 1,

wherein the curve extraction unit extracts the curve using an extremal value of the curvature of the sampling points.

3. The curve-shape modeling device according to claim 2,

wherein the curve extraction unit extracts the curve when the curve extraction unit determines that one of extremal points having the extremal values assigned to the curvature of the sampling points provides a same curve as at least one of one or more preceding extremal points and one or more succeeding extremal points in a case where a ratio between the curvature of the one of extremal points and a value obtained by smoothing the curvature of the one or more preceding extremal points or a value obtained by smoothing the curvature of the one or more succeeding extremal points is disposed within a predetermined range.

4. The curve-shape modeling device according to claim 3,

wherein the curve extraction unit adjusts the curvature by smoothing the extremal points, and

wherein the curve extraction unit extracts the curve when the curve extraction unit determines that the one of extremal points having the extremal values assigned to an adjusted curvature of the sampling points provides a same curve as at least one of one or more preceding extremal points and one or more succeeding extremal points in a case where a ratio between the adjusted curvature of the one of extremal points and a value obtained by smoothing the adjusted curvature of the one or more preceding extremal points or a value obtained by smoothing the adjusted curvature of the one or more succeeding extremal points is disposed within the predetermined range.

5. The curve-shape modeling device according to claim 1,

wherein the steady section curvature determination unit determines an average value or a median of curvatures in the curve extracted by the curve extraction unit as the curvature of the steady section.

6. The curve-shape modeling device according to claim 1,

wherein the steady section curvature determination unit determines an average value or a median of extremal values for curvatures in the curve extracted by the curve extraction unit.

7. The curve-shape modeling device according to claim 1,

wherein the steady section curvature determination unit determines whether the curve extracted by the curve extraction unit protrudes upward or downward,

wherein the steady section curvature determination unit determines a local maximal value of the curvature in the curve as the curvature of the steady section when the curve protrudes upward, and

wherein the steady section curvature determination unit determines a local minimal value of the curvature in the curve as the curvature of the steady section when the curve protrudes downward.

8. The curve-shape modeling device according to claim 7,

wherein the steady section curvature determination unit determines an average value or a median of curvatures in the curve extracted by the curve extraction unit as the curvature of the steady section when the curve has a form between an upward protruding curve and a downward protruding curve.

9. The curve-shape modeling device according to claim 7,

wherein the steady section curvature determination unit determines an average value or a median of extremal values for curvatures in the curve extracted by the curve extraction unit as the curvature of the steady section when the curve has a form between an upward protruding curve and a downward protruding curve.

10. The curve-shape modeling device according to claim 1,

wherein the curve entry and exit determination unit sequentially determines whether a curvature at each sampling point, which is arranged forward or backward from a predetermined sampling point in the curve along the route, exceeds the curvature range, and

wherein the curve entry and exit determination unit determines a sampling point where the curvature exceeds the curvature range to be the start point or the end point of the steady section.

11. The curve-shape modeling device according to claim 10,

wherein the predetermined sampling point in the curve has a local maximal curvature or a local minimal curvature in the curve.

12. The curve-shape modeling device according to claim 1,

wherein the curve entry and exit determination unit sequentially determines whether a curvature at each sampling point, which is arranged forward or backward from a preceding boundary or a succeeding boundary of the curve extracted by the curve extraction unit along the route, exceeds the curvature range, and

wherein the curve entry and exit determination unit determines a sampling point where the curvature exceeds the curvature range to be the start point or the end point of the steady section.

13. The curve-shape modeling device according to claim 1,

wherein the curve entry and exit determination unit sequentially determines whether a curvature at each sampling point, which is arranged in a direction from an outside of the curve extracted by the curve extraction unit toward the curve along the route, is disposed within the curvature range, and

wherein the curve entry and exit determination unit determines a sampling point where the curvature is disposed within the curvature range to be the start point or the end point of the steady section.

14. The curve-shape modeling device according to claim 1, further comprising:

a relaxation curve section determination unit that determines the relaxation curve section according to the start point and the end point of the steady section determined by the curve entry and exit determination unit.

15. A vehicle information processing system that processes information about a vehicle based on detected vehicle information and a route modeled by the curve-shape modeling device according to claim 1.

16. A curve-shape modeling method of classifying a plurality of sampling points acquired along a route into a linear section, a relaxation curve section and a steady section to model a curve shape of the route, the method comprising:

extracting a curve from the sampling points based on a curvature at the sampling points;

determining a curvature of the steady section based on a curvature at the sampling points included in an extracted curve; and

setting a predetermined curvature range including the curvature of the steady section, and determining a start point and an end point of the steady section based on the curvature range.

17. A non-transitory tangible computer readable medium comprising instructions being executed by a computer, the instructions including a computer-implemented curve-shape modeling method of classifying a plurality of sampling points acquired along a route into a linear section, a relaxation curve section and a steady section to model a curve shape of the route, the method comprising:

extracting a curve from the sampling points based on a curvature at the sampling points;

determining a curvature of the steady section based on a curvature at the sampling points included in a curve extracted at the extracting of the curve; and

setting a predetermined curvature range including the curvature of the steady section, and determining a start point and an end point of the steady section based on the curvature range.