JP2004212324A - Buried object detection device - Google Patents

Abstract

Provided is a buried object exploration device that can accurately detect a position up to a buried object buried in the ground.
One or a plurality of transmitting antennas for transmitting electromagnetic waves, and a reflected electromagnetic wave having a different directional angle from each other and receiving reflected electromagnetic waves reflected from a buried object are provided at a tip of a leading conductor of a propulsion device for excavating and propelling an underground. And a plurality of receiving antennas.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a buried object exploration device for exploring a buried object that is buried underground and cannot be seen from the ground.
[0002]
[Prior art]
Conventionally, when constructing pipes for housing communication cables etc. underground by the non-drilling method, the leading conductor of the propulsion device that excavates and promotes underground works to prevent collisions with nearby buried objects. A buried object exploring device for exploring the buried object is provided at the tip of the body. This buried object detection device is based on the principle of radar.It transmits electromagnetic waves toward the ground in front and transmits electromagnetic waves reflected from buried objects as obstacles buried in the ground. It has a configuration for detecting the presence or absence of a buried object using a receiving antenna for receiving.
[0003]
FIG. 8 is an explanatory view showing a surface of a tip portion of a conventional buried object detection device. The tip of the embedded object exploration apparatus 4 shown in FIG. 1 includes a transmission antenna 41 for transmitting electromagnetic waves illuminating the ground and a reception antenna 43 for receiving electromagnetic waves reflected by the embedded object. FIG. 9 shows a side view of the buried object detection device 4 for detecting the buried object 50 buried in the ground, and two arrows indicate electromagnetic waves transmitted from the transmitting antenna 41 and reflected from the buried object 50, The electromagnetic waves received by the receiving antenna 43 are conceptually represented.
[0004]
[Problems to be solved by the invention]
However, the above-mentioned conventional buried object detection device can detect only the presence or absence of a buried object in front of the propulsion device at the time of the exploration, so that it can accurately detect the position of the distance to the buried object, direction, etc. could not. Therefore, since the exact position to the buried object is unknown, the operation of the propulsion device has to be stopped when the presence of the buried object is detected.
[0005]
The present invention has been made in view of the above, and an object of the present invention is to provide a buried object exploration device that can accurately detect a position of a buried object buried underground.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention according to claim 1 is provided at the tip of a leading conductor of a propulsion device for excavating and propelling an underground, and searches for a buried object buried in the ground based on transmission and reception of electromagnetic waves. An embedded object exploration apparatus, comprising one or more transmitting antennas for transmitting electromagnetic waves, and a plurality of receiving antennas having different directivity angles and receiving reflected electromagnetic waves reflected from the embedded object, respectively. Make a summary.
[0007]
According to the first aspect of the present invention, the mounting positions and combinations of one or a plurality of transmitting antennas and a plurality of receiving antennas mounted on the tip of the leading conductor of the propulsion device are appropriately adjusted, and the plurality of receiving antennas By analyzing the received electromagnetic wave data, it is possible to accurately detect not only the presence or absence of a buried object to be searched but also the position (distance, direction, etc.) to the buried object.
[0008]
The term "buried object" as used herein means not only communication cables, metal pipes, concrete pipes, and other conduits, but also all obstacles to the propulsion system including peculiar geology, such as bedrock.
[0009]
According to a second aspect of the present invention, in the buried object exploration apparatus according to the first aspect, two transmitting antennas whose polarization directions are orthogonal to each other are provided as the transmitting antennas, and the plurality of receiving antennas having different directivity angles are provided. The point is that at least two receiving antennas whose polarization directions when receiving reflected electromagnetic waves are orthogonal to each other are provided for each polarization direction.
[0010]
According to the second aspect of the present invention, a buried object including two transmitting antennas whose polarization directions are different from each other by 90 degrees (orthogonal to each other) and two pairs of receiving antennas whose polarization directions are different from each other by 90 degrees. Providing the exploration device makes it possible to accurately detect the position (distance, direction, etc.) to the buried object.
[0011]
According to a third aspect of the present invention, there is provided a buried object exploration apparatus according to the first aspect, wherein a plurality of pairs of a transmitting antenna and a receiving antenna are provided near each other and form a pair.
[0012]
According to the third aspect of the present invention, a position (distance to an embedded object) is provided by providing an embedded object detection device provided with a plurality of pairs of a transmitting antenna and a receiving antenna arranged near each other and forming a pair. , Direction, etc.) can be accurately detected.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings.
[0014]
FIG. 1 is an explanatory diagram showing the configuration of the surface of the tip of the buried object search device according to the first embodiment of the present invention. The tip of the embedded object detection device 1 shown in FIG. 1 is attached to, for example, the tip of the leading conductor of the propulsion device. In the following description, the distal end of the buried object detection device may be simply referred to as the buried object detection device.
[0015]
The buried object detection device 1 is provided with a transmitting antenna 11 and two receiving antennas 13a and 13b at its tip. The receiving antennas 13a and 13b have different directivity angles. As shown in the side view of the buried object exploration apparatus 1 in FIG. 2, the directional angle is such that the electromagnetic wave beam of the receiving antenna 13a covers the electromagnetic wave beam of the other receiving antenna 13b from the front to the upper side in the drawing. It is appropriately adjusted to cover the lower part from the front. As a result, at least one of the two receiving antennas can receive all reflected electromagnetic waves reflected from the buried object in front. More specifically, the angle of the electromagnetic wave beam is about 40 to 50 degrees (more preferably, about 45 degrees), and the two receiving antennas 13a are arranged so that the electromagnetic wave beams having such directivity overlap and cover the front. And 13b are arranged. The forward search distance of the electromagnetic wave beam is about 1.0 m to 2.0 m (more preferably, about 1.5 m).
[0016]
The embedded object exploration apparatus 1 according to the present embodiment applies the principle of radar, and each transmission and reception antenna is a half-pitch 36-pin digital-only interface having, for example, a teardrop element shape. The electromagnetic wave transmitted from the transmitting antenna 11 has a transmission pulse width of about 1.0 ns to 1.5 ns (corresponding to a radio wave having a center frequency of about 660 MHz to 1 GHz), more preferably about 1.2 ns (a radio wave having a center frequency of about 830 MHz). The present invention is not necessarily limited to this, and a continuous wave may be used as an electromagnetic wave. Each of the transmitting and receiving antennas further has a function of transmitting and receiving data to and from the main body of the buried object search device 1.
[0017]
The main body of the buried object exploration apparatus 1 is composed of a circuit having a high output and a low noise, a transmission wave generator for generating an electromagnetic wave (hereinafter referred to as a transmission wave) transmitted from the transmission antenna 11, and a reception antenna 13a. A / D converter for converting the reflected electromagnetic wave (hereinafter referred to as a reflected wave) from the buried object received at each of 13b and 13b into an analog signal, for analyzing the analog-converted reflected wave to detect the position of the buried object And at least a monitor that outputs a search result of the buried object detected by the arithmetic processing unit. Among these, the resolution of the A / D converter is about 16 bits (about 8 bits for display and storage).
[0018]
More specifically, the arithmetic processing in the arithmetic processing unit measures the difference in the intensity of the reflected waves received by the receiving antennas 13a and 13b, the difference in the time in which each receiving antenna receives the reflected waves, and the like. The position of the buried object is detected by appropriately adding a correction according to the conditions of the exploration place.
[0019]
FIG. 3 is an explanatory diagram conceptually illustrating a case where the receiving antenna 13a receives a reflected wave stronger than the receiving antenna 13b. In the figure, a transmission wave and two reflected waves are conceptually represented by arrows. As shown in FIG. 3, the reflected waves received by the two receiving antennas 13a and 13b each have a difference in intensity depending on the position of the buried object (the length of the arrow of the reflected wave generally indicates the difference in intensity). It is possible to accurately detect the position of the buried object in the Z direction (vertically downward direction in FIG. 3).
[0020]
In addition to the case described with reference to FIG. 3, for example, when the receiving antennas 13a and 13b simultaneously receive reflected waves of the same intensity, it is possible to detect the presence of an embedded object in the propulsion direction in front of the propulsion device.
[0021]
According to the first embodiment of the present invention described above, a buried object exploration device equipped with a transmitting antenna and two receiving antennas having different directivity angles is mounted on the tip of the leading conductor of the propulsion device or the like. The position of the buried object existing ahead in the propulsion direction can be accurately detected based on information such as the intensity and time of the reflected waves received by the two receiving antennas. As a result, it is possible to prevent an accident in which the leading conductor of the propulsion device collides with a nearby buried object.
[0022]
When installing a new pipeline near the existing pipeline (metal pipe, concrete pipe, etc.) that is propelled underground without excavating from the ground, ensure a certain distance from the existing pipeline. Construction is required. If the buried object detection device of the present embodiment is applied to such a new pipeline, not only the front, but also the position between the buried objects in the vertical direction can be accurately detected, so that the above-described requirement is satisfied. It will be possible to construct new pipeline construction.
[0023]
FIG. 4 is an explanatory diagram showing the configuration of the surface of the distal end portion of the buried object search device according to the second embodiment of the present invention. In addition to the transmitting antenna 21a and the receiving antennas 23a and 23b corresponding to the transmitting antenna 11 and the receiving antennas 13a and 13b of the first embodiment, the transmitting antenna A transmitting antenna 21b whose polarization direction is different from that of 21a by 90 degrees, and receiving antennas 23c and 23d whose directions of polarization are different from those of the receiving antennas 23a and 23b by 90 degrees are provided.
[0024]
The two transmitting antennas 21a and 21b are arranged on a square plane perpendicular to the propulsion direction provided at the center of the tip of the buried object detection device 2 such that the center of each antenna coincides with the center of the plane. On the other hand, the receiving antennas 23a, 23b, 23c and 23d are arranged around the plane so as to generate a symmetrical positional relationship with the plane. Each receiving antenna has a different directional angle from each other similarly to the first embodiment, forms a predetermined angle with respect to the plane, and radiates symmetrically on four slopes from each side of the square forming the plane. Respectively. Therefore, when the buried object detection device 2 is viewed from the side, it has the same projected shape as the side view of the buried object detection device 1 shown in FIG.
[0025]
FIG. 5 is a perspective view of the above-described buried object inspection device 2 as viewed from substantially the front. Instead of providing the inclined surface for mounting the receiving antenna described above, it is also possible to provide all the transmitting antennas and the receiving antennas on the same plane with the front end surface as one plane. Also in this case, it is needless to say that the surface of the distal end portion when the embedded object exploration apparatus 2 is viewed from the front is the same as that in FIG.
[0026]
By mounting the four receiving antennas as described above, the all-sky direction in front of the buried object detection device 2 can be covered by the four receiving antennas, and when the buried object is detected ahead, It is possible to obtain not only the vertical direction (corresponding to the Z direction in FIG. 3) of the buried object, but also horizontal position information orthogonal to the vertical direction.
[0027]
The configuration of the buried object exploration apparatus according to the present embodiment other than the transmitting and receiving antennas is the same as that of the above-described first embodiment except that a transmission wave generation unit and the like according to the increase in the number of transmitting antennas and receiving antennas are added. This is the same as the embodiment. Also, the method of detecting the position of the buried object based on the reflected wave does not have any particular difference other than adding a process associated with an increase in the number of receiving antennas, particularly a process in the horizontal direction, to the arithmetic process itself.
[0028]
It goes without saying that the second embodiment of the present invention described above has the same effects as the first embodiment. Further, according to the present embodiment, it is also possible to obtain horizontal position information with respect to the tip of the leading conductor of the propulsion device, so that it is possible to more accurately detect the position of the buried object.
[0029]
FIG. 6 is an explanatory diagram illustrating a configuration of a surface of a tip portion of a buried object search device according to a third embodiment of the present invention. In the embedded object exploration apparatus 3 shown in FIG. 7, two pairs of transmitting and receiving antennas (transmitting antenna 31a and receiving antenna 33a) and (transmitting antenna 31b and receiving antenna 33b) are shown in the side view of FIG. So as to face different directions from each other. As a result, similarly to the above embodiment, the receiving antennas 33a and 33b have different directivity angles, and it is possible to detect the position of the buried object by analyzing the reflected waves received by each receiving antenna. The angle formed between the two transmitting / receiving antenna pairs when the distal end is mounted is appropriately adjusted according to the purpose and application. In view of the properties of the antenna, even if the mounting positions of the transmitting antenna and the receiving antenna shown in FIGS. 6 and 7 are reversed, there is no difference in the obtained effects.
[0030]
In the embedded object exploration apparatus according to the third embodiment of the present invention described with reference to FIGS. 6 and 7, the configuration other than the transmitting / receiving antenna and the operation when detecting an embedded object are the same as those of the above two embodiments. Essentially the same. Therefore, it goes without saying that the third embodiment of the present invention has the same effect as the above two embodiments.
[0031]
It should be noted that the buried object exploration apparatus according to the present invention can be mounted on various devices used for exploring underground buried objects in addition to being mounted on the tip of the leading conductor of the propulsion device as described above. Needless to say, the same effects as described above can be obtained when the device is mounted on such a device. As described above, the present invention can naturally include various embodiments having the same effects as described above.
[0032]
【The invention's effect】
According to the present invention described above, it is possible to provide a buried object exploration device that can accurately detect a position up to a buried object buried underground.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram illustrating a surface of a tip portion of a buried object search device according to a first embodiment of the present invention.
FIG. 2 is a side view of a distal end portion of the buried object search device according to the first embodiment of the present invention.
FIG. 3 is an explanatory diagram showing a search by the buried object search device according to the first embodiment of the present invention.
FIG. 4 is an explanatory diagram illustrating a surface of a tip portion of an embedded object search device according to a second embodiment of the present invention.
FIG. 5 is a side view of a tip of a buried object search device according to a second embodiment of the present invention.
FIG. 6 is an explanatory diagram showing a surface of a tip end portion of a buried object search device according to a third embodiment of the present invention.
FIG. 7 is a perspective view of a distal end portion of a buried object detection device according to a second embodiment of the present invention as viewed from substantially the front.
FIG. 8 is an explanatory view showing a surface of a tip portion of a conventional embedded object search device.
FIG. 9 is a side view of a tip portion of a conventional embedded object detection device.
[Explanation of symbols]
1, 2, 3, 4 buried object detection device 11, 21a, 21b, 31a, 31b, 41 transmitting antennas 13a, 13b, 23a, 23b, 23c, 23d, 33a, 33b, 43 receiving antenna 50 buried object

Claims (3)

A buried object exploration device that is provided at the tip of the leading conductor of a propulsion device that excavates and promotes underground, and that searches for buried objects buried in the ground based on transmission and reception of electromagnetic waves,
One or more transmitting antennas for transmitting electromagnetic waves,
A buried object exploration apparatus, comprising: a plurality of receiving antennas having different directivity angles and receiving reflected electromagnetic waves reflected from the buried object. As the transmission antenna, while providing two transmission antennas whose polarization directions are orthogonal to each other,
2. The buried object according to claim 1, wherein at least two reception antennas whose polarization directions when receiving reflected electromagnetic waves are orthogonal to each other are provided for each polarization direction as the plurality of reception antennas having different directivity angles. 3. Exploration equipment. 2. The buried object exploration apparatus according to claim 1, wherein a plurality of pairs of a transmitting antenna and a receiving antenna are provided near each other and form a pair.

Images