VEHICLE-MOUNTED RADAR APPARATUS

• US 20130207834A1
• Filed: 02/12/2013
• Published: 08/15/2013
• Est. Priority Date: 02/13/2012
• Status: Active Grant

• Current Assignee: DENSO Corporation, Mazda Motor Corporation
• Original Assignee: DENSO Corporation, Mazda Motor Corporation
• Inventors: Mizutani, Akiyoshi, Shimizu, Koji, Okazaki, Haruki, Matsuoka, Keiji
• Granted Patent: US 9,073,548 B2
• Time in Patent Office: Days
• US Class Current: 342/70
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: G01S 13/345 using triangular modulation
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/93185 Controlling the brakes
• CPC Class Codes: G01S 2013/9319 Controlling the accelerator
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/9325 for inter-vehicle distance regulation, e.g. navigating in platoons
• CPC Class Codes: G01S 7/411 Identification of targets based on measurements of radar reflectivity G01S7/415 takes precedence

Abstract

A vehicle-mounted radar apparatus for transmitting radar waves toward the outside of a vehicle mounting the apparatus thereon and receiving the radar waves reflected from an object to thereby acquire information about the object. In the apparatus, a target detection unit transmits and receives the radar waves to detect positions of targets. An object position determination unit determines a position of the object reflecting the radar waves on the basis of the positions of the targets. A representative target selection unit selects a representative target from the targets. A same-object target selection unit selects targets belonging to the same object as the representative target. A large-vehicle determination unit determines whether or not the object is a large vehicle on the basis of a number of targets selected by the same-object target selection unit and reflection wave received powers for the respective targets.

Claims

1. A vehicle-mounted radar apparatus for transmitting radar waves toward the outside of a vehicle mounting the apparatus thereon, the vehicle being hereinafter referred to as a radar-mounting vehicle, and receiving the radar waves reflected from an object to acquire information about the object, the apparatus comprising:

a target detection unit that transmits and receives the radar waves to detect positions of targets reflecting the radar waves;

an object position determination unit that determines a position of the object reflecting the radar waves on the basis of the positions of the targets detected by the target detection unit;

a representative target selection unit that selects one of the targets detected by the target detection unit that fulfills a predetermined representative-target designation condition for designating a representative of the targets detected by the target detection unit;

a same-object target selection unit that selects, from the targets detected by the target detection unit, targets that fulfill a predetermined same-object target selection condition for determining which of the targets detected by the target detection unit belongs to the same object as the representative target, the representative target and the targets selected by the same-object target selection unit other than the representative target forming together a same-object target group, and the object that each target of the same-object target group belongs to being referred to as a specific reflecting object; and

a large-vehicle determination unit that determines whether or not the specific reflecting object is a large vehicle on the basis of at least one of a number of targets of the same-object target group and a power spectrum indicative of reflection wave received powers for the respective targets of the same-object target group.

2. The apparatus of claim 1, wherein the object position determination unit sets a position of a target inclusion region so that all the targets of the same-object target group are included in the target inclusion region, thereby determining the position of the specific reflecting object.

3. The apparatus of claim 2, further comprising a target inclusion region changing unit that, when it is determined by the large-vehicle determination unit that the specific reflecting object is a large vehicle, enlarges the target inclusion region.

4. The apparatus of claim 3, wherein the target inclusion region changing unit, in response to whether or not it is determined by the large-vehicle determination unit that the specific reflecting object is a large vehicle, changes the target inclusion region between a target inclusion region for large vehicles and a target inclusion region for non-large vehicles, the target inclusion region for large vehicles is larger than the target inclusion region for non-large vehicles.

5. The apparatus of claim 4, wherein the target inclusion region changing unit, when it is determined by the large-vehicle determination unit that the specific reflecting object is a large vehicle, changes the target inclusion region to the target inclusion region for large vehicles.

6. The apparatus of claim 1, wherein the large-vehicle determination unit determines whether or not the number of targets of the same-object target group is equal to or greater than a predetermined threshold target number for large-vehicle determination, and when it is determined that the number of targets of the same-object target group is equal to or greater than the predetermined threshold target number for large-vehicle determination, determines that the specific reflecting object is a large vehicle.

7. The apparatus of claim 1, wherein the large-vehicle determination unit determines whether or not a reflection wave received power for one of the targets of the same-object target group that fulfills a predetermined target selection condition for selecting a target used by the large-vehicle determination unit to determine whether or not the specific reflecting object is a large vehicle is equal to or greater than a predetermined threshold received power for large-vehicle determination, and when it is determined that the reflection wave received power for the target that fulfills the predetermined target selection condition is equal to or greater than the predetermined threshold received power for large-vehicle determination, determines that the specific reflecting object is a large vehicle.

8. The apparatus of claim 1, wherein the large-vehicle determination unit determines whether or not the number of targets of the same-object target group is equal to or greater than a predetermined threshold target number for large-vehicle determination, and when it is determined that the number of targets of the same-object target group is equal to or greater than the predetermined threshold target number for large-vehicle determination, further determines whether or not a reflection wave received power for one of the targets of the same-object target group that fulfills a predetermined target selection condition for selecting a target used by the large-vehicle determination unit to determine whether or not the specific reflecting object is a large vehicle is equal to or greater than a predetermined threshold received power for large-vehicle determination, and when it is determined that the reflection wave received power for the target that fulfills the predetermined target selection condition is equal to or greater than the predetermined threshold received power for large-vehicle determination, determines that the specific reflecting object is a large vehicle.

9. The apparatus of claim 7, wherein the predetermined target selection condition states that the target used by the large-vehicle determination unit to determine whether or not the specific reflecting object is a large vehicle is a target of the same-object target group having a maximum frequency-peak intensity in the power spectrum.

10. The apparatus of claim 8, wherein the predetermined target selection condition states that the target used by the large-vehicle determination unit to determine whether or not the specific reflecting object is a large vehicle is a target of the same-object target group having a maximum frequency-peak intensity in the power spectrum.

11. The apparatus of claim 1, wherein the predetermined same-object target selection condition comprises at least one of:

a first condition that a difference in longitudinal position between the representative target and a target belonging to the specific reflecting object is less than a predetermined threshold value of longitudinal position difference;

a second condition that a difference in lateral position between the representative target and a target belonging to the specific reflecting object is less than a predetermined threshold value of lateral position difference;

a third condition that a difference in relative speed between the representative target and a target belonging to the specific reflecting object is less than a predetermined threshold value of relative speed difference; and

a fourth condition that a difference in reflection wave received power between the representative target and a target belonging to the specific reflecting object is less than a predetermined threshold value of reflection wave received power difference.

12. The apparatus of claim 1, wherein the predetermined representative-target designation condition states that the representative target is a target, of the targets detected by the target detection unit, closest to the radar-mounting vehicle.

13. The apparatus of claim 1, wherein the predetermined representative-target designation condition states that the representative target is a target, of the targets detected by the target detection unit, having a maximum frequency-peak intensity in the power spectrum.

14. The apparatus of claim 2, wherein the target inclusive range of region is a rectangular region defined by a length along a traveling direction of the radar-mounting vehicle and a width along a vehicle-width direction of the radar-mounting vehicle.