Method and apparatus for recognizing presence of objects

• US 8,810,445 B2
• Filed: 04/26/2011
• Issued: 08/19/2014
• Est. Priority Date: 04/27/2010
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Ogawa, Takashi, Sakai, Hiroshi
• Primary Examiner(s): Brainard, Timothy A
• Application Number:
  US13/093,904
• Publication Number:
  US 20110260909A1
• Time in Patent Office: 1,211 Days
• Field of Search: 342 70- 72
• US Class Current: 342/70
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/4876 by removing unwanted signals G01S7/495 takes precedence

Abstract

An object recognition apparatus is provided, which enhances accuracy in recognizing more than one object to be detected closely located along a scan direction. In the apparatus, measured-distance datums included in an area formed by those measured-distance datums which are spaced apart by a distance of not more than a predetermined allowable value are grouped as one candidate area. The candidate area, if it has a size larger than a specified value, is regarded as a special candidate area. An object area on an image datum corresponding to the special candidate area is subjected to an image recognition process to define the range of the objects residing therein. The special candidate area is divided at a border between the objects based on the defined range. All candidate areas including the divided new candidate areas are subjected to a tracing process to confirm an object in each candidate area.

Claims

1. An object recognition apparatus that recognizes presence of an object to be detected based on the results of sequentially emitting probe waves along a predetermined scan direction so that the probe waves are adjacently juxtaposed, the apparatus comprising:

location acquiring means that acquires a measured-distance datum indicating the location of an object, the measured-distance datum being generated for each emission of the probe wave based on a reflected wave from the object, the reflected wave being obtained as a result of emitting the probe wave;

image acquiring means that acquires an image datum that is an image of an area at least including a scan area of the probe waves;

candidate detecting means that detects a candidate area in which measured-distance datums are grouped as belonging to the same group, based on the measured-distance datums acquired by the location acquiring means, the grouped measured-distance datums being included in an area formed by those measured-distance datums which are spaced apart by a distance of not more than a predetermined allowable value;

special candidate area determining means that determines a special candidate area in the candidate area detected by the candidate detecting means, the special candidate area having a probability of including at least two or more objects to be detected which are adjacently located along a predetermined direction;

range detecting means that recognizes an object by subjecting the image datum acquired by the image acquiring means to an image recognition process and detects a range of measured-distance datums in which the objects to be detected reside, the objects being imaged in an area on the image datum, the area corresponding to the special candidate area; and

candidate dividing means that divides the special candidate area at a border position between objects, the border position corresponding to an end of the range of the measured-distance datums detected by the range detecting means.

2. The object recognition apparatus according to claim 1, wherein:

the range detecting means performs the image recognition process for an area in the image datum, the area corresponding to the special candidate area.

3. The object recognition apparatus according to claim 2, wherein:

the range detecting means determines the candidate area as being the special candidate area if the candidate area has a size larger than a specified value that indicates the size of a unit body of each of the objects to be detected.

4. The object recognition apparatus according to claim 3, wherein:

the apparatus comprises re-detecting means that allows the range detecting means to detect a range of the measured-distance datums, using the group of measured-distance datums as the special candidate area, if the group of measured-distance datums has a size larger than the specified value, the group of measured-distance datums resulting from the division performed by the candidate dividing means.

5. The object recognition apparatus according to claim 4, wherein:

the apparatus emits the probe waves using at least a vehicle'"'"'s widthwise direction as one of the scan directions; and

the range detecting means defines the special candidate area in which the vehicle'"'"'s widthwise direction is used as the predetermined direction.

6. The object recognition apparatus according to claim 5, wherein:

the apparatus emits the probe waves using at least a vehicle'"'"'s heightwise direction as one of the scan directions; and

the range detecting means defines the special candidate area in which the vehicle'"'"'s heightwise direction is used as the predetermined direction.

7. The object recognition apparatus according to claim 1, wherein:

the range detecting means determines the candidate area as being the special candidate area if the candidate area has a size larger than a specified value that indicates the size of a unit body of each of the objects to be detected.

8. The object recognition apparatus according to claim 7, wherein:

the apparatus comprises re-detecting means that allows the range detecting means to detect a range of the measured-distance datums, using the group of measured-distance datums as the special candidate area, if the group of measured-distance datums has a size larger than the specified value, the group of measured-distance datums resulting from the division performed by the candidate dividing means.

9. The object recognition apparatus according to claim 8, wherein:

the apparatus emits the probe waves using at least a vehicle'"'"'s widthwise direction as one of the scan directions; and

the range detecting means defines the special candidate area in which the vehicle'"'"'s widthwise direction is used as the predetermined direction.

10. The object recognition apparatus according to claim 9, wherein:

the apparatus emits the probe waves using at least a vehicle'"'"'s heightwise direction as one of the scan directions; and

the range detecting means defines the special candidate area in which the vehicle'"'"'s heightwise direction is used as the predetermined direction.

11. The object recognition apparatus according to claim 1, wherein:

the apparatus comprises re-detecting means that allows the range detecting means to detect a range of the measured-distance datums, using the group of measured-distance datums as the special candidate area, if the group of measured-distance datums has a size larger than the specified value, the group of measured-distance datums resulting from the division performed by the candidate dividing means.

12. The object recognition apparatus according to claim 11, wherein:

the apparatus emits the probe waves using at least a vehicle'"'"'s widthwise direction as one of the scan directions; and

the range detecting means defines the special candidate area in which the vehicle'"'"'s widthwise direction is used as the predetermined direction.

13. The object recognition apparatus according to claim 12, wherein:

the apparatus emits the probe waves using at least a vehicle'"'"'s heightwise direction as one of the scan directions; and

the range detecting means defines the special candidate area in which the vehicle'"'"'s heightwise direction is used as the predetermined direction.

14. The object recognition apparatus according to claim 1, wherein:

the apparatus emits the probe waves using at least a vehicle'"'"'s widthwise direction as one of the scan directions; and

the range detecting means defines the special candidate area in which the vehicle'"'"'s widthwise direction is used as the predetermined direction.

15. The object recognition apparatus according to claim 14, wherein:

the apparatus emits the probe waves using at least a vehicle'"'"'s heightwise direction as one of the scan directions; and

the range detecting means defines the special candidate area in which the vehicle'"'"'s heightwise direction is used as the predetermined direction.

16. The object recognition apparatus according to claim 1, wherein:

the apparatus emits the probe waves using at least a vehicle'"'"'s heightwise direction as one of the scan directions; and

the range detecting means defines the special candidate area in which the vehicle'"'"'s heightwise direction is used as the predetermined direction.

17. A non-transitory computer-readable medium storing therein a program for allowing a computer to function as an object recognition apparatus that recognizes presence of an object to be detected based on the results of sequentially emitting probe waves along a predetermined scan direction so that the probe waves are adjacently juxtaposed, the program allowing the computer to perform:

a location acquiring step that acquires a measured-distance datum indicating the location of an object, the measured-distance datum being generated for each emission of the probe wave based on a reflected wave from the object, the reflected wave being obtained as a result of emitting the probe wave;

an image acquiring step that acquires an image datum that is an image of an area at least including a scan area of the probe waves;

a candidate detecting step that detects a candidate area in which measured-distance datums are grouped as belonging to the same group, based on the measured-distance datums acquired by the location acquiring procedure, the grouped measured-distance datums being included in an area formed by those measured-distance datums which are spaced apart by a distance of not more than a predetermined allowable value;

a special candidate area determining step that determines a special candidate area in the candidate area detected by the candidate detecting procedure, the special candidate area having a probability of including at least two or more objects to be detected which are adjacently located along a predetermined direction;

a range detecting step that recognizes an object by subjecting the image datum acquired by the image acquiring procedure to an image recognition process and detects a range of measured-distance datums in which the objects to be detected reside, the objects being imaged in an area on the image datum, the area corresponding to the special candidate area; and

a candidate dividing step that divides the special candidate area at a border position between objects, the border position corresponding to an end of the range of the measured-distance datums detected by the range detecting procedure.

18. A method, implemented in a object recognition apparatus including at least a processor, of recognizing presence of an object to be detected based on the results of sequentially emitting probe waves along a predetermined scan direction so that the probe waves are adjacently juxtaposed, the method comprising:

acquiring, by location acquiring means of the object recognition apparatus, a measured-distance datum indicating the location of an object, the measured-distance datum being generated for each emission of the probe wave based on a reflected wave from the object, the reflected wave being obtained as a result of emitting the probe wave;

acquiring, by image acquiring means of the object recognition apparatus, an image datum that is an image of an area at least including a scan area of the probe waves;

detecting, by candidate detecting means of the object recognition apparatus, a candidate area in which measured-distance datums are grouped as belonging to the same group, based on the measured-distance datums acquired, the grouped measured-distance datums being included in an area formed by those measured-distance datums which are spaced apart by a distance of not more than a predetermined allowable value;

determining, by special candidate area determining means of the object recognition apparatus, a special candidate area in the candidate area detected by the candidate detecting means, the special candidate area having a probability of including at least two or more objects to be detected which are adjacently located along a predetermined direction;

recognizing, by range detecting means of the object recognition apparatus, an object by subjecting the acquired image datum to an image recognition process such that a range of measured-distance datums is detected in which the objects to be detected reside, the objects being imaged in an area on the image datum, the area corresponding to the special candidate area; and

dividing, by candidate dividing means of the object recognition apparatus, the special candidate area at a border position between objects, the border position corresponding to an end of the range of the detected measured-distance datums.