Immersion object detection system and method

• US 6,535,159 B1
• Filed: 05/21/2002
• Issued: 03/18/2003
• Est. Priority Date: 12/01/2000
• Status: Expired due to Fees

• Current Assignee: Omron Corporation
• Original Assignee: Omron Corporation
• Inventors: Shimamoto, Hiroshi, Nishiguchi, Tadao, Kawamoto, Ryuji
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US09/996,594
• Time in Patent Office: 301 Days
• Field of Search: 342/27, 342/28, 342/56, 342/58, 342/59, 342/90, 342/107, 342/109, 342/113, 342/114, 342/115, 342/192, 342/196, 340/541, 340/552, 340/565, 340/567
• US Class Current: 342/27
• CPC Class Codes: G01S 13/04 Systems determining presence of a target based on relative movement of target G01S13/56
• CPC Class Codes: G01S 13/343 using sawtooth modulation
• CPC Class Codes: G01S 13/886 for alarm systems alarms with electrical actuation G08B13/22
• CPC Class Codes: G01S 5/0284 Relative positioning
• CPC Class Codes: G01S 7/352 Receivers
• CPC Class Codes: G01S 7/356 involving particularities of FFT processing

Abstract

To provide an immersion object detection system capable of detecting an immersion object within a detection target area and specifying a position thereof irrespective of a short distance/long distance.

A millimeter wave is irradiated to a detection area from a millimeter-wave RF unit through an antenna unit, and the reflected wave is detected. In the case that an immersion object exists in a short-distance area from a radar unit, the directly reflected waves from the immersion object is analyzed, thereby specifying the position of the immersion object, and in the case that the immersion object exists in a long-distance area from the radar unit, the position of the immersion object is specified in accordance with the position of the reflection member which cannot detect among the group of reflection members placed within the detection area.

Claims

1. An immersion object detection method comprising the steps of:

irradiating a wave to a detection target area;

detecting a reflected wave from the detection target area by reflected wave detection means; and

determining that an immersion object exists within the detection target area in a case that the reflected wave cannot be detected from at least one reflection member among a plurality of reflection members placed within the detection target area, and simultaneously specifying a position of the immersion object in accordance with a position of the reflection member which cannot detect.

2. The immersion object detection method according to claim 1, wherein the plurality of reflection members are placed such that distances from the reflected wave detection means to each of the reflection members are different, respectively, and

the position of the immersion object is specified as any position between a reflection member having the furthest distance from the reflected wave detection means among the reflection members which can detect the reflected wave and a reflection member having the nearest distance from the reflected wave detection means among the reflection members which cannot detect the reflected wave.

3. The immersion object detection method according to claim 1, wherein the plurality of reflection members are placed such that at least one reflection member among the plurality of reflection members has a different direction with respect to the reflected wave detection means as compared with the other reflection members.

4. The immersion object detection method according to claim 1, wherein in a case that the immersion object exists in a short-distance area having a distance of not more than a predetermined value from the reflected wave detection means, the position of the immersion object is specified by analyzing a directly reflected wave from the immersion object, and in a case that the immersion object exists in a long-distance area having a distance of not less than a predetermined value from the reflected wave detection means, the position of the immersion object is specified in accordance with the position of the reflection member which cannot detect.

5. The immersion object detection method according to claim 1, comprising the steps of:

placing a reference object for comparing with the immersion object in the short-distance area within the detection target area;

irradiating the wave to the detection target area, thereby detecting the reflected wave from the reference object by the reflected wave detection means; and

creating reference object information based on the reflected wave to be detected,

wherein in the case that the immersion object exists in the short-distance area, the position of the immersion object is specified, and the reference object information is compared with immersion object information created based on the reflected wave from the immersion object detected by the reflected wave detection means, thereby specifying the kind of the immersion object.

6. The immersion object detection method according to claim 1, wherein the wave to be irradiated is an electric wave.

7. The immersion object detection method according to claim 1, comprising the steps of:

irradiating the wave to the detection target area in a state that no immersion object exists within the detection target area, thereby detecting the reflected wave from the reflection member by the reflected wave detection means; and

creating normal state information with respect to the reflection member based on the reflected wave to be detected,

wherein the reflection member which cannot detect is specified by comparing the normal state information with information created based on the reflected wave detected by the reflected wave detection means.

8. An immersion object detection method comprising the steps of:

irradiating a wave to a detection target area;

detecting a reflected wave from the detection target area by reflected wave detection means;

determining that an immersion object exists within the detection target area in a case that the reflected wave cannot be detected from one reflection member placed within the detection target area, and simultaneously specifying a position of the immersion object in accordance with a position of the reflection member which cannot detect,

wherein the position of the immersion object is specified by analyzing a directly reflected wave from the immersion object in a case that the immersion object exists in a short-distance area having a distance of not more than a predetermined value from the reflected wave detection means, while in a case that the immersion object exists in a long-distance area having a distance of not less than the predetermined value from the reflected wave detection means, the reflected wave cannot be detected from the reflection member by the reflected wave detection means, so that existence of the immersion object is specified between a position in which a distance from the reflected wave detection means is the predetermined value and a position where the reflection member is placed.

9. The immersion object detection method according to claim 8, comprising the steps of:

placing a reference object for comparing with the immersion object in the short-distance area within the detection target area;

irradiating the wave to the detection target area, thereby detecting the reflected wave from the reference object by the reflected wave detection means; and

creating reference object information based on the reflected wave to be detected,

wherein the position of the immersion object is specified in the case that the immersion object exists in the short-distance area, and the kind of the immersion object is specified by comparing the reference object information with immersion object information created based on the reflected wave from the immersion object detected by the reflected wave detection means.

10. The immersion object detection method according to claim 8, wherein the wave to be irradiated is an electric wave.

11. The immersion object detection method according to claim 8, comprising the steps of:

irradiating the wave to the detection target area in a state that no immersion object exists within the detection target area, thereby detecting the reflected wave from the reflection member by the reflected wave detection means; and

creating normal state information with respect to the reflection member based on the reflected wave to be detected,

wherein the reflection member which cannot detect is specified by comparing the normal state information with information created based on the reflected wave detected by the reflected wave detection means.

12. An immersion object detection method comprising the steps of:

irradiating a wave to a detection target area;

detecting a reflected wave from the detection target area by reflected wave detection means; and

determining that an immersion object exists within the detection target area in a case that the reflected wave cannot be detected from one reflection member placed within the detection target area,

wherein the wave to be irradiated is an electric wave.

13. The immersion object detection method according to claim 12, comprising the steps of:

irradiating the wave to the detection target area in a state that no immersion object exists within the detection target area, thereby detecting the reflected wave from the reflection member by the reflected wave detection means; and

creating normal state information with respect to the reflection member based on the reflected wave to be detected,

wherein the reflection member which cannot detect is specified by comparing the normal state information with information created based on the reflected wave detected by the reflected wave detection means.

14. An immersion object detection system comprising:

wave irradiation means of irradiating a wave to a detection target area;

a plurality of reflection members placed within the detection target area;

reflected wave detection means in which the wave irradiated from the wave irradiation means detects a reflected wave from the detection target area; and

immersion object detection means of detecting an immersion object within the detection target area,

wherein in a case that the reflected wave detection means cannot detect the reflected wave from at least one reflection member among the plurality of reflection members, the immersion object detection means determines that the immersion object exists within the detection target area and specifies a position of the immersion object in accordance with a position of the reflection member which cannot detect.

15. The immersion object detection system according to claim 14, wherein the plurality of reflection members are placed such that distances from the reflected wave detection means to each of the reflection members are different, respectively, and the immersion object detection means determines that the immersion object exists between a reflection member having a furthest distance from the reflected wave detection means among the reflection members which can detect the reflected wave and a reflection member having a nearest distance from the reflected wave detection means among the reflection members which cannot detect the reflected wave.

16. The immersion object detection system according to claim 14, wherein the plurality of reflection members are placed such that at least one reflection member among the plurality of reflection members has a different direction with respect to the reflected wave detection means as compared with the other reflection members.

17. The immersion object detection system according to claim 14, wherein in a case that the immersion object exists in a short-distance area where a distance from the reflected wave detection means is not more than a predetermined value, the immersion object detection means specifies the position of the immersion object by analyzing a directly reflected wave from the immersion object, and in a case that the immersion object exists in a long-distance area where a distance from the reflected wave detection means is not less than the predetermined value, the immersion object detection means specifies the position of the immersion object in accordance with the position of the reflection member which cannot detect.

18. The immersion object detection system according to claim 14, further comprising

a storage means of previously placing a reference object for comparing with the immersion object in the short-distance area within the detection target area, thereby storing reference object information of the reflected wave from the reference object detected by the reflected wave detection means,

wherein the immersion object detection means compares the reference object information stored in the storage means with information detected by the reflected wave detection means in a case that the immersion object is detected in the short-distance area, thereby specifying the kind of the immersion object.

19. The immersion object detection system according to claim 14, wherein the wave irradiated from the wave irradiation means is an electric wave.

20. The immersion object detection system according to claim 14, further comprising

a storage means of storing normal state information of the reflected wave from the reflection member, detected by the reflected wave detection means, in a state that no immersion object exists within the detection target area,

wherein the immersion object detection means compares the normal state information stored in the storage means with information detected by the reflected wave detection means, thereby specifying the reflection member which cannot detect.

21. The immersion object detection system according to claim 14, wherein the reflection members are placed within a range of a predetermined height from the ground surface.

22. The immersion object detection system according to claim 14, wherein the reflection members are objects previously placed within the detection target area.

23. The immersion object detection system according to claim 14, wherein a deflection means of deflecting a course of the wave irradiated by the wave irradiation means is provided between the wave irradiation means and the reflection members.

24. A radar device used in the immersion object detection system according to claim 14.

25. A reflection member used in the immersion object detection system according to claim 14.

26. An immersion object detection system comprising:

wave irradiation means of irradiating a wave to a detection target area;

a reflection member placed within the detection target area;

reflected wave detection means in which the wave irradiated from the wave irradiation means detects the reflected wave from the detection target area; and

immersion object detection means of detecting the immersion object within the detection target area,

wherein in a case that the immersion object exists in a short-distance area where a distance from the reflected wave detection means is not more than a predetermined value, the immersion object detection means specifies a position of the immersion object by analyzing a directly reflected wave from the immersion object, and in a case that the immersion object exists in a long-distance area where a distance from the reflected wave detection means is not less than the predetermined value, the reflected wave detection means cannot detect the reflected wave from the reflection member, so that the immersion object detection means specifies that the immersion object exists between a position in which a distance from the reflected wave detection means is the predetermined value and a position where the reflection member is placed.

27. The immersion object detection system according to claim 26, further comprising

a storage means of previously placing a reference object for comparing with the immersion object in the short-distance area within the detection target area, thereby storing reference object information of the reflected wave from the reference object detected by the reflected wave detection means,

wherein the immersion object detection means compares the reference object information stored in the storage means with information detected by the reflected wave detection means in a case that the immersion object is detected in the short-distance area, thereby specifying the kind of the immersion object.

28. The immersion object detection system according to claim 26, wherein the wave irradiated from the wave irradiation means is an electric wave.

29. The immersion object detection system according to claim 26, further comprising

a storage means of storing normal state information of the reflected wave from the reflection member, detected by the reflected wave detection means, in a state that no immersion object exists within the detection target area,

wherein the immersion object detection means compares the normal state information stored in the storage means with information detected by the reflected wave detection means, thereby specifying the reflection member which cannot detect.

30. The immersion object detection system according to claim 26, wherein the reflection members are placed within a range of a predetermined height from the ground surface.

31. The immersion object detection system according to claim 26, wherein the reflection members are objects previously placed within the detection target area.

32. The immersion object detection system according to claim 26, wherein a deflection means of deflecting the a course of the wave irradiated by the wave irradiation means is provided between the wave irradiation means and the reflection members.

33. A radar device used in the immersion object detection system according to claim 26.

34. A reflection member used in the immersion object detection system according to claim 26.

35. An immersion object detection system comprising:

wave irradiation means of irradiating a wave to a detection target area;

a reflection member placed within the detection target area;

reflected wave detection means in which the wave irradiated from the wave irradiation means detects the reflected wave from the detection target area; and

immersion object detection means of detecting the immersion object within the detection target area,

wherein the wave irradiated from the wave irradiation means is an electric wave, and

in a case that the reflected wave detection means cannot detect the reflected wave from the reflection member, the immersion object detection means determines that the immersion object exists within the detection target area, and the immersion object detection means specifies that the immersion object exists between a position of the reflected wave detection means and a position of the reflection member.

36. The immersion object detection system according to claim 35, further comprising

a storage means of storing normal state information of the reflected wave from the reflection member, detected by the reflected wave detection means, in a state that no immersion object exists within the detection target area,

wherein the immersion object detection means compares the normal state information stored in the storage means with information detected by the reflected wave detection means, thereby specifying the reflection member which cannot detect.

37. The immersion object detection system according to claim 35, wherein the reflection members are placed within a range of a predetermined height from the ground surface.

38. The immersion object detection system according to claim 35, wherein the reflection members are objects previously placed within the detection target area.

39. The immersion object detection system according to claim 35, wherein a deflection means of deflecting a course of the wave irradiated by the wave irradiation means is provided between the wave irradiation means and the reflection members.

40. A radar device used in the immersion object detection system according to claim 35.

41. A reflection member used in the immersion object detection system according to claim 35.