Mine detector and inspection apparatus

• US 20030136249A1
• Filed: 10/28/2002
• Published: 07/24/2003
• Est. Priority Date: 10/21/1998
• Status: Active Grant

• Current Assignee: Omron Corporation
• Original Assignee: Omron Corporation
• Inventors: Tomita, Hiroshi, Inoue, Yoshitaka, Toguchi, Yoichi
• Granted Patent: US 6,679,153 B2
• Time in Patent Office: Days
• US Class Current: 89/1.13
• CPC Class Codes: F41H 11/12 Means for clearing land minefields; Systems specially adapted for detection of landmines
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
• CPC Class Codes: G01S 13/885 for ground probing prospecting or detecting using electromagnetic waves G01V3/12
• CPC Class Codes: G01S 13/89 for mapping or imaging
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 7/02 of systems according to group G01S13/00
• CPC Class Codes: G01S 7/04 Display arrangements
• CPC Class Codes: G01V 3/15 specially adapted for use during transport, e.g. by a person, vehicle or boat
• CPC Class Codes: G01V 3/17 operating with electromagnetic waves operating with millimetre waves G01V8/005

Abstract

A mine detector is provided for detecting buried land mines safely and promptly. A sensor head (12) is connected to a detector body (1) through hinges (11-1 to 11-4) and arms (12-1 to 12-3). The sensor head (12) includes a transmitting and receiving means for emitting electromagnetic impulses to the ground within a range of detection of land mines. When the transmitting and receiving means receives electromagnetic waves reflected from a land mine, information on the three-dimensional structure of the land mine buried under the ground is generated on the basis of the time of arrival of the reflected wave, the level of the reflected wave and the x and y coordinates of the transmitting and receiving means, and the information is displayed on a display (1). The detector is also applicable to the inspection of steel rods and bars for concrete reinforcement.

Claims

1. A mine detector for detecting a mine buried in the ground, characterized by comprising:

transmitting and receiving means for transmitting an electromagnetic wave toward the ground of a range intended to detect said land mine for scanning, and receiving a reflected wave thereof;

position detecting means for detecting the position of said transmitting and receiving means at a time said transmitting and receiving means receives said reflected wave;

an internal ground structure information generating means for generating information indicative of a three-dimensional structure in the ground based on a period of time from the transmission of said electromagnetic wave by said transmitting and receiving means to the reception of the reflected wave, a received level of said reflected wave, and a position detected by said position detecting means;

image information generating means for generating image information for display from information indicative of said three-dimensional structure generated by said internal ground structure information generating means; and

display means for displaying an image based on said image information generated by said image information generating means.

2. A mine detector according to claim 1, characterized by further comprising:

mode switching means for switching a first/mode for instructing said display means to display an image indicative of the scanned range of the ground, and a second mode for instructing said display means to display an image representative of a state in the ground, generated by said image information generating means,

wherein said display means displays the image indicative of the scanned range of said ground when switched to said first mode, and displays the image representative of a state in the ground when switched to said second mode.

3. A mine detector according to claim 2, characterized by further comprising:

marking means for marking a predetermined mark at a predetermined position when said transmitting and receiving means is scanned a state where said mine detector has been switched to said second mode.

4. A mine detector according to claim 1, characterized by further comprising:

scaling factor specifying means for specifying a scaling factor of an image displayed on said display means,

wherein said display means displays said image in the ground at a scaling factor specified by said scaling factor specifying means.

5. A mine detector according to claim 1, characterized in that:

said internal ground structure generating means generates three-dimensional information of said land mine positioned in the ground; and

said image information generating means generates a three-dimensional display image of said land mine positioned in the ground.

6. A mine detector according to claim 1, characterized by further comprising:

determining means for determining a material of said land mine positioned in the ground based on a signal corresponding to the level of said reflected wave.

7. A mine detector according to claim 6, characterized in that:

said determining means determines at least metal and plastic materials.

8. A mine detector according to claim 6, characterized in that:

said display means displays different materials in different colors corresponding to the result of determination made by said determining means.

9. A mine detector according to claim 1, characterized in that:

said display means further displays a shape which serves as a reference for the size of said land mine in the ground.

10. A mine detector according to claim 1, characterized in that:

said display means is formed integrally with said transmitting and receiving means.

11. A mine detector for detecting a land mine buried in the ground, characterized by comprising:

transmitting and receiving means for transmitting an electromagnetic wave toward the ground of a range intended to detect said land mine for scanning, and receiving a reflected wave thereof;

position detecting means for detecting the position of said transmitting and receiving means at a time said transmitting and receiving means receives said reflected wave;

an internal ground structure information generating means for generating information indicative of a three-dimensional structure in the ground based on a period of time from the transmission of said electromagnetic wave by said transmitting and receiving means to the reception of the reflected wave, a received level of said reflected wave, and a position detected by said position detecting means;

calibration means for calibrating the value of a dielectric coefficient of the ground which is a parameter for use in said internal ground structure information generating means;

image information generating means for generating image information for display from information indicative of said three-dimensional structure generated by said internal ground structure information generating means; and

display means for displaying an image based on said image information generated by said image information generating means.

12. A mine detector according to claim 11, characterized by further comprising:

generating means which is constructed integrally with said transmitting and receiving means and generates at least three light beams;

light receiving means for receiving said three light beams and outputting signals corresponding to positions at which said light beams are received; and

position detecting means for detecting the position of said transmitting and receiving means from an output of said light receiving means.

13. A mine detector according to claim 12, characterized in that:

said generating means generates said three light beams of substantially flat plate shape in cross section.

14. A mine detector according to claim 12, characterized in that:

said light receiving means comprises at least one line sensor; and

said position detecting means calculates the position of said transmitting and receiving means based on spacings between positions at which said line sensor receives said three light beams.

15. A mine detector according to claim 12, characterized by further comprising:

converting means for converting said three light beams to substantially collimated light.

16. A mine detector according to claim 12, characterized in that:

said light receiving means comprises at least two line sensors;

said generating means inclines said three light beams of substantially flat plate shape in cross section at a predetermined angle with respect to said two line sensors; and

said position detecting means calculates a three-dimensional position of said transmitting and receiving means and rotation about the three-dimensional axes based on spacings between positions at which said two line sensors receive said three light beams.

17. An inspection apparatus characterized by comprising:

transmitting and receiving means for transmitting an electromagnetic wave to an object under inspection in a range in which said object under inspection is scanned, and receiving a reflected wave thereof;

a position detecting means for detecting a position at which said transmitting and receiving means receives said reflected wave;

processing means for processing a signal indicative of a three-dimensional structure inside of said object under inspection based on a period of time from the transmission of said electromagnetic wave by said transmitting and receiving means to the reception of the reflected wave, a received level of said reflected wave, and a position detected by said position detecting means;

calibration means for calibrating said processing by said processing means;

generating means for generating an image signal from said signal indicative of the three-dimensional structure processed by said processing means; and

display means for displaying an image based on said image signal generated by said generating means.

18. An inspection apparatus according to claim 17, characterized in that:

mode switching means for switching a first mode for instructing said display means to display an image indicative of the range in which said object under inspection has been scanned, and a second mode for instructing said display means to display an image representative of a three-dimensional structure inside of said object under inspection, generated by said image information generating means,

wherein said display means displays the image indicative of the range in which said object under inspection has been scanned when switched to said first mode, and displays the image representative of the three-dimensional structure inside of said object under inspection when switched to said second mode.

19. An inspection apparatus according to claim 18, characterized by further comprising:

displayed cross section switching means for switching an image displayed on said display means to an image of a plane cross section inside of said object under inspection generated by said generating means, or to an image of a lateral cross section inside of said object under inspection.

20. An inspection apparatus according to claim 19, characterized by further comprising:

symbol display means for superimposing a predetermined symbol on said display means corresponding to a position of said transmitting and receiving means when said transmitting and receiving means scans in a state in which said mode switching means has switched to said second mode, and said displayed cross section switching means has switched to display an image of a plane cross section inside of said object under inspection on said display means.

21. An inspection apparatus according to claim 19, characterized by further comprising:

depth specifying means for specifying a depth of a plane cross section when an image of the plane cross section inside of said object under inspection is displayed on said display means,

wherein said display means display an image of a plane cross section inside of said object under inspection at a depth specified by said depth specifying means.

22. An inspection apparatus according to claim 19, characterized by further comprising:

direction specifying means for specifying a direction of a lateral cross section when an image of the lateral cross section inside of said object under inspection is displayed on said display means,

wherein said display means displays an image of a lateral cross section inside of said object under inspection in a direction specified by said direction specifying means.

23. An inspection apparatus according to claim 18, characterized by further comprising:

marking means for marking a predetermined mark at a predetermined position when said transmitting and receiving means is scanned in a state in which switching has been made to display an image of a plane cross section inside of said object under inspection on said display means.

24. An inspection apparatus according to claim 23, characterized by further comprising:

distinguishing means for distinguishing a material of an article positioned in said object under inspection based on a signal corresponding to the intensity of said reflected wave.

25. An inspection apparatus according to claim 24, characterized in that:

said distinguishing means distinguishes at least metal from plastic.

26. An inspection apparatus according to claim 24, characterized in that:

said display means displays different materials in different colors corresponding to the result of a determination made by said determining means.

27. An inspection apparatus according to claim 23, characterized in that:

said display means further displays a shape which serves as a reference for the size of an article in said object under inspection.

28. An inspection apparatus according to claim 17, characterized by further comprising:

scaling factor specifying means for specifying a scaling factor of an image displayed on said display means,

wherein said display means displays an image inside of said object under inspection at a scaling factor specified by said scaling factor specifying means.

29. An inspection apparatus according to claim 17, characterized in that:

said generating means generates a three-dimensional image of an article positioned in said object under inspection; and

said inspection apparatus further comprises three-dimensional image display means for displaying a three-dimensional image of said article positioned in said object under inspection.

30. An inspection apparatus according to claim 17, characterized in that:

said display means is formed integrally with said transmitting and receiving means.

31. An inspection apparatus according to claim 17, characterized in that:

said calibration means performs calibration by setting the dielectric coefficient of said object under inspection to a plurality of predetermined values.

32. An inspection apparatus according to claim 17, characterized by further comprising:

adding means for adding a mark indicative of a position at which scanning is started or a position at which the scanning is finished on said object under inspection.

33. An inspection apparatus according to claim 17, characterized in that:

said display means simultaneously displays an image of plane cross section inside of said object under inspection and an image of lateral cross section inside of said object under inspection.

34. An inspection apparatus according to claim 33, characterized in that:

said display means displays the position of a plane of the image of the lateral cross section inside of said object under inspection in line with the position of a plane of the image of the plane cross section inside of said object under inspection.

35. An inspection apparatus characterized by comprising:

transmitting and receiving means for transmitting an electromagnetic wave to an object under inspection in a range in which said object under inspection is scanned, and receiving a reflected wave thereof;

inspecting means for inspecting the interior of said object under inspection from an output of said transmitting and receiving means;

generating means constructed integrally with said transmitting and receiving means for generating at least three light beams;

light receiving means for receiving said three light beams and outputting signals corresponding to positions at which said light beams are received; and

position detecting means for detecting a position of said transmitting and receiving means from an output of said light receiving means.

36. An inspection apparatus according to claim 35, characterized in that:

said generating means generates said three light beams of substantially flat plate shape in cross section.

37. An inspection apparatus according to claim 35, characterized in that:

said light receiving means comprises at least one line sensor; and

said position detecting means calculates the position of said transmitting and receiving means based on spacings between positions at which said line sensor receives said three light beams.

38. An inspection apparatus according to claim 35, characterized by further comprising:

converting means for converting said three light beams to substantially collimated light.

39. An inspection apparatus according to claim 35, characterized in that:

said light receiving means comprises at least two line sensors;

said generating means inclines said three light beams of substantially flat plate shape in cross section at a predetermined angle with respect to said two line sensors; and

said position detecting means calculates a three-dimensional position of said transmitting and receiving means and rotation about the three-dimensional axes based on spacings between positions at which said two line sensors receive said three light beams.