Vehicle detector and vehicle detecting method

• US 20060089799A1
• Filed: 10/11/2005
• Published: 04/27/2006
• Est. Priority Date: 10/21/2004
• Status: Active Grant

• Current Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Original Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Inventors: Endoh, Kenjiro
• Granted Patent: US 7,509,217 B2
• Time in Patent Office: Days
• US Class Current: 701/300
• CPC Class Codes: G01S 13/726 Multiple target tracking
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 7/415 Identification of targets based on measurements of movement associated with the target

Abstract

A vehicle detector includes a detecting apparatus and a determining apparatus. If a plurality of detection points detected by the detecting apparatus forms a group of detection points, the determining apparatus sets a determining virtual window encompassing the group of detection points and determines whether the group of detection points is likely to represent the one vehicle based on a state of movement of the group of detection points with respect to the determining virtual window.

Claims

1. A vehicle detector having a detecting apparatus for detecting at least part of an object as a detection point by receiving reflected electromagnetic waves repeatedly emitted toward an area containing the object and capable of detecting another vehicle existing at least in the vicinity of a host vehicle based on a detection result of the detection point, the vehicle detector comprising:

a determining apparatus which, if a plurality of detection points detected by the detecting apparatus with one radiating operation forms one group of detection points in the form of an aggregate of a predetermined or larger number of detection points in a predetermined area, determines that the group of detection points is likely to be one vehicle and sets a determining virtual window encompassing the group of detection points,

which, if a change in the group of detection points with respect to a plurality of detection points obtained with a subsequent radiating operation is small, determines that the group of detection points is more likely to be one vehicle, and

which repeats detection and determination for each radiating operation, and if a change in the group of detection points with respect to a plurality of detection points obtained with each radiating operation is small, determines that the group of detection points is much more likely to be one vehicle and repeats a subsequent radiating operation.

2. The vehicle detector according to claim 1, wherein, if a change in the number of detection points obtained with the subsequent radiating operation in the determining virtual window is equal to or less than a predetermined number, it is determined that the group of detection points is more likely to be the one vehicle and the determining virtual window is caused to move following a movement of the group of detection points in the determining virtual window.

3. The vehicle detector according to claim 2, wherein, detection and determination are repeated for each radiating operation, continuity of determination is checked from a relationship between detection points obtained with each radiating operation and the determining virtual window, and it is determined that the group of detection points is much more likely to be the one vehicle and a subsequent radiating operation is repeated if there is continuity in the determination.

4. The vehicle detector according to claim 3, wherein, a speed and an intensity of the group of reflection points relative to the host vehicle are provided in addition to a condition of the continuity to determine a state of movement of the group of reflection points relative to the determining virtual window.

5. The vehicle detector according to claim 2, wherein the determining apparatus calculates a representative coordinate point in the group of detection points before the movement and a representative coordinate point in the group of detection points after the movement, and moves the determining virtual window by the amount of movement of the representative coordinate point in the group of detection points after the movement relative to the representative coordinate point in the group of detection points before the movement to cause the determining virtual window to track the group of detection points.

6. The vehicle detector according to claim 5, wherein the representative coordinate point is a center of gravity in the group of detection points.

7. The vehicle detector according to claim 1, wherein, if a state of movement preventing a determination that the detected object corresponding to the group of detection points is likely to be one vehicle is indicated in a process of repeating the determination, the determining apparatus maintains the determining virtual window at the current position instead of causing the determining virtual window to track the group of reflection points,

if the state of movement is continued a predetermined or larger number of times, the determining apparatus cancels the setting of the determining virtual window maintained at the current position, and

if the state of movement is eliminated before the predetermined number of times is reached and a state of movement allowing a determination that the detected object corresponding to the group of detection points is likely to be one vehicle is indicated again, the determining apparatus causes the determining virtual window maintained at the current position to track the group of detection points again.

8. The vehicle detector according to claim 1, wherein the determining apparatus is capable of making an individual determination as to a plurality of groups of detection points different from one another.

9. The vehicle detector according to claim 1, wherein the detecting apparatus is a radar apparatus.

10. The vehicle detector according to claim 9, wherein the radar apparatus emits laser beams at predetermined intervals in a desired direction.

11. A vehicle detecting method for detecting at least part of an object as a detection point by receiving reflected electromagnetic waves repeatedly emitted toward an area containing the object to detect another vehicle existing at least in the vicinity of a host vehicle based on a detection result of the detection point, the vehicle detecting method comprising:

determining that a group of a plurality of detection points detected with one radiating operation is likely to be one vehicle and setting a determining virtual window encompassing the group of detection points, if the plurality of detection points forms one group of detection points in the form of an aggregate of a predetermined or larger number of detection points in a predetermined area;

determining that the group of detection points is more likely to be one vehicle if a change in the group of detection points with respect to a plurality of detection points obtained with a subsequent radiating operation is small; and

repeating detection and determination for each radiating operation, and determining that the group of detection points is much more likely to be one vehicle and repeating a subsequent radiating operation if a change in the group of detection points with respect to a plurality of detection points obtained with each radiating operation is small.

12. The vehicle detecting method according to claim 11, wherein, if a change in the number of detection points obtained with the subsequent radiating operation in the determining virtual window is equal to or less than a predetermined number, it is determined that the group of detection points is more likely to be the one vehicle and the determining virtual window is caused to move following a movement of the group of detection points in the determining virtual window.

13. The vehicle detecting method according to claim 12, wherein, detection and determination are repeated for each radiating operation, continuity of determination is checked from a relationship between detection points obtained with each radiating operation and the determining virtual window, and it is determined that the group of detection points is much more likely to be the one vehicle and a subsequent radiating operation is repeated if there is continuity in the determination.

14. The vehicle detecting method according to claim 13, wherein, a speed and an intensity of the group of reflection points relative to the host vehicle are provided in addition to a condition of the continuity to determine a state of movement of the group of reflection points relative to the determining virtual window.

15. The vehicle detecting method according to claim 12, wherein a representative coordinate point in the group of detection points before the movement and a representative coordinate point in the group of detection points after the movement are calculated, and the determining virtual window is moved by the amount of movement of the representative coordinate point in the group of detection points after the movement relative to the representative coordinate point in the group of detection points before the movement to cause the determining virtual window to track the group of detection points.

16. The vehicle detecting method according to claim 15, wherein the representative coordinate point is a center of gravity in the group of detection points.

17. The vehicle detecting method according to claim 11, wherein, if a state of movement preventing a determination that the detected object corresponding to the group of detection points is likely to be one vehicle is indicated in a process of repeating the determination, the determining virtual window is maintained at the current position instead of causing the determining virtual window to track the group of reflection points,

if the state of movement is continued a predetermined or larger number of times, the setting of the determining virtual window maintained at the current position is cancelled, and

if the state of movement is eliminated before the predetermined number of times is reached and a state of movement allowing a determination that the detected object corresponding to the group of detection points is likely to be one vehicle is indicated again, the determining virtual window maintained at the current position is caused to track the group of detection points again.

18. The vehicle detecting method according to claim 11, wherein an individual determination is made as to a plurality of groups of detection points different from one another.

19. The vehicle detecting method according to claim 11, wherein the object is detected with a radar apparatus.

20. The vehicle detecting method according to claim 19, wherein the radar apparatus emits laser beams at predetermined intervals in a desired direction.