Object detection apparatus and object detection program

• US 10,649,084 B2
• Filed: 04/07/2017
• Issued: 05/12/2020
• Est. Priority Date: 04/11/2016
• Status: Active Grant

• Current Assignee: Denso PS Corporation (DENSO Corporation)
• Original Assignee: Denso PS Corporation (DENSO Corporation)
• Inventors: Katsura, Shoji, Takano, Gaku, Kobori, Wataru, Iwasaki, Tetsuya
• Primary Examiner(s): Akonai, Olumide Ajibade
• Application Number:
  US15/481,795
• Publication Number:
  US 20170293030A1
• Time in Patent Office: 1,131 Days
• CPC Class Codes: G01S 13/56 for presence detection presence detection using near field arrangements G01V3/00, e.g. G01V3/08, G01V3/12; burglar, theft or intruder alarms with electrical actuation G08B13/22 - G08B13/26
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/46 Indirect determination of position data
• CPC Class Codes: G01S 17/50 Systems of measurement based on relative movement of target
• CPC Class Codes: G01S 17/87 Combinations of systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 7/415 Identification of targets based on measurements of movement associated with the target
• CPC Class Codes: G01S 7/4806 Road traffic laser detectors

Abstract

An object detection apparatus measures a distance to a detected object at each irradiation angle, based on reflected waves of electromagnetic waves irradiated from a laser light irradiating unit at each irradiation angle. The apparatus determines whether the measured distance remains unchanged for prescribed period of time, for each irradiation angle, and stores the determined distance in a storage unit as a stationary object distance in association with the irradiation angle. The apparatus compares the current measured distance and the stored distances, and determines whether a stationary object distance matching the current distance is present among the stored distances. The apparatus initially compares the shortest stationary object distance among the stored distances with the current distance, and upon determining that a stationary object distance matching the current distance is present, stops the comparison of the current distance and the stored distances that have not been compared with the current distance.

Claims

1. An object detection apparatus that detects an object in a detection area based on reflected waves of irradiated electromagnetic waves, the object detection apparatus comprising:

a memory; and

a processor programmed to;

measure a plurality of distances to a detected object at a corresponding one of a plurality of irradiation angles, based on the reflected waves of the electromagnetic waves irradiated at the corresponding one of the plurality of irradiation angles;

determine whether the plurality of measured distances remain unchanged for a prescribed period of time, for the corresponding one of the plurality of irradiation angles;

store, in the memory, the plurality of distances determined to have remained unchanged as a plurality of stationary object distances in association with the corresponding one of the plurality of irradiation angles;

compare a plurality of measured current distances and the plurality of stationary object distances stored in the memory for the corresponding one of the plurality of irradiation angles, initially comparing a shortest stationary object distance among the plurality of stationary object distances stored in the memory to the current distance, for the corresponding one of the plurality of irradiation angles;

determine whether at least one of the plurality of stationary object distances matching the current distance is present among the plurality of stationary object distances stored in the memory; and

upon determining that at least one of the plurality of stationary object distances matching at least one of the plurality of current distances is present, stopping a comparison between the plurality of current distances and the plurality of stationary object distances that have not yet been compared with the plurality of current distances among the plurality of stationary object distances stored in the memory,

wherein the object detection apparatus is provided at a fixed position.

2. The object detection apparatus according to claim 1, wherein the processor is programmed to:

delete, from the memory, at least one of the plurality of the stationary object distances that is shorter than the at least one of the plurality of distances determined to have remained unchanged, among the plurality of stationary object distances stored in the memory that are associated with the corresponding one of the plurality of irradiation angles.

3. The object detection apparatus according to claim 1, wherein the processor is programmed to:

delete, from the memory, at least one of the plurality of stationary object distances shorter than at least one of the plurality of the current distances, among the plurality of stationary object distances stored in the memory that are associated with the corresponding one of the plurality of irradiation angles.

4. The object detection apparatus according to claim 1, wherein the processor is programmed to:

identifying a moving object by determining that an object detected at the corresponding one of the plurality of irradiation angles does not have a matching one of the plurality of stationary object distances.

5. The object detection apparatus according to claim 1, wherein:

the electromagnetic waves are laser light.

6. The object detection apparatus according to claim 1, wherein the processor is programmed to:

compare the plurality of current distances to the plurality of stationary object distances stored in the memory in order from the shortest stationary object distance, for the corresponding one of the plurality of irradiation angles.

7. The object detection apparatus according to claim 6, wherein the processor is programmed to:

delete, from the memory, at least one of the plurality of stationary object distances that is shorter than at least one of the plurality of distances determined to have remained unchanged, among the plurality of stationary object distances stored in the memory that are associated with the corresponding one of the plurality of irradiation angles.

8. The object detection apparatus according to claim 6, wherein the processor is programmed to:

delete, from the memory, at least one of the plurality of stationary object distances shorter than at least one of the plurality of current distances, among the plurality of stationary object distances stored in the memory that are associated with the corresponding one of the plurality of irradiation angles.

9. An object detection apparatus that detects an object in a detection area based on reflected waves of irradiated electromagnetic waves, the object detection apparatus comprising:

a memory; and

a processor programmed to;

measure a plurality of distances to a detected object at a corresponding one of a plurality of irradiation angles, based on the reflected waves of the electromagnetic waves irradiated at the corresponding one of the plurality of irradiation angles;

determine whether the plurality of measured distances remain unchanged for a prescribed period of time, for the corresponding one of the plurality of irradiation angles;

store, in the memory, the plurality of distances determined to have remained unchanged as a plurality of stationary object distances in association with the corresponding one of the plurality of irradiation angles;

compare a plurality of measured current distance and the plurality of stationary object distances stored in the memory for the corresponding one of the plurality of irradiation angles;

determine whether at least one of the plurality of stationary object distances matching at least one of the plurality of current distances is present among the plurality of stationary object distances stored in the memory; and

delete, from the memory, at least one of the plurality of stationary object distances that is shorter than at least one of the plurality of distances determined to have remained unchanged, among the plurality of stationary object distances stored in the memory that are associated with the corresponding one of the plurality of irradiation angles,

wherein the object detection apparatus is provided at a fixed position.

10. The object detection apparatus according to claim 9, wherein the processor is programmed to:

identifying a moving object by determining that an object detected at the corresponding one of the plurality of irradiation angles does not have a matching one of the plurality of stationary object distances.

11. The object detection apparatus according to claim 9, wherein:

the electromagnetic waves are laser light.

12. An object detection apparatus that detects an object in a detection area based on reflected waves of irradiated electromagnetic waves, the object detection apparatus comprising:

a memory; and

a processor programmed to;

measure a plurality of distances to a detected object at a corresponding one of a plurality of irradiation angles, based on the reflected waves of the electromagnetic waves irradiated at the corresponding one of the plurality of irradiation angles;

determine whether the plurality of measured distances remain unchanged for a prescribed period of time, for the corresponding one of the plurality of irradiation angles;

store, in the memory, the plurality of distances determined to have remained unchanged as a plurality of stationary object distances in association with the corresponding one of the plurality of irradiation angles;

compare a plurality of current measured distances and the plurality of stationary object distances stored in the memory for the corresponding one of the plurality of irradiation angles;

determine whether at least one of the plurality of stationary object distances matching the at least one of the plurality of current distances is present among the plurality of stationary object distances stored in the memory; and

delete, from the memory, at least one of the plurality of stationary object distances that is shorter than at least one of the plurality of current measured distances, among the plurality of stationary object distances stored in the memory that are associated with the corresponding one of the plurality of irradiation angles,

wherein the object detection apparatus is provided at a fixed position.

13. The object detection apparatus according to claim 12, wherein the processor is programmed to:

identifying a moving object by determining that an object detected at the corresponding one of the plurality of irradiation angles does not have a matching one of the plurality of stationary object distances.

14. The object detection apparatus according to claim 12, wherein:

the electromagnetic waves are laser light.

15. A non-transitory computer-readable storage medium storing an object detection program for an object detection apparatus that detects an object in a detection area based on reflected waves of irradiated electromagnetic waves, the object detection program causing a computer to perform:

a distance measuring process to measure a plurality of distances to a detected object at a corresponding one of a plurality of irradiation angles, based on the reflected waves of the irradiated electromagnetic waves at the corresponding one of the plurality of irradiation angles;

a stationary-state determining process to determine whether the plurality of measured distances remain unchanged for a prescribed period of time, for the corresponding one of the plurality of irradiation angles;

a storing process to store, in a memory provided in the computer, the plurality of distances determined to have remained unchanged by the stationary-state determining process as a plurality of stationary object distances in association with the corresponding one of the plurality of irradiation angles; and

a comparison determining process to compare a plurality of measured current distances and the plurality of stationary object distances stored in the memory for the corresponding one of the plurality of irradiation angles, and to determine whether at least one of the plurality of stationary object distances matching the at least one of the plurality of current distances is present among the stationary object distances stored in the memory,

wherein the comparison determining process initially compares a shortest stationary object distance among the plurality of stationary object distances stored in the memory with the current distance, for the corresponding one of the plurality of irradiation angles, and upon determining that at least one of the plurality of stationary object distances matching at least one of the plurality of current distances is present, stops a comparison between the plurality of current distances and the plurality of stationary object distances that have not yet been compared with the plurality of current measured distances among the plurality of stationary object distances stored in the memory, and

the object detection apparatus is provided at a fixed position.

16. The non-transitory computer-readable storage medium storing the object detection program according to claim 15, wherein the object detection program causes the computer to further perform:

a deleting process to delete, from the memory, at least one of the plurality of stationary object distances that is shorter than at least of the plurality of distances determined to have remained unchanged, among the plurality of stationary object distances stored in the memory that are associated with the corresponding one of the plurality of irradiation angles.

17. The non-transitory computer-readable storage medium storing the object detection program according to claim 15, wherein the object detection program causes the computer to further perform:

a deleting process to delete, from the memory, at least one of the plurality of stationary object distances that is shorter than at least one of the plurality of measured current distances, among the plurality of stationary object distances stored in the memory that are associated with the corresponding one of the plurality of irradiation angles.