JP2002214356A - Underground radar apparatus for guided drilling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an underground radar apparatus for a guided drilling method enabling the processing and displaying of signals to follow drilling speed, while being economical. SOLUTION: The underground radar apparatus for the guided drilling method includes a plurality of antenna elements AT1 to AT4 positioned along the outer peripheral surface of the front end of an underground drill moved in the direction of a rotation axis while rotating under the ground; the characteristics of the antenna elements are synthesized to form a nondirectional synthetic antenna around the rotation axis. The radar apparatus includes an estimating and reporting means which estimates that the signal received by the synthetic antenna contains a wave reflected by a reflecting object and then transmits a report signal indicative of it to an above-ground device if the amount of delay at the time of reception of the signal received by the synthetic antenna is generally monotonously increased or decreased over a predetermined length or more in the moving direction and if a change in the amount of delay in the moving direction is equal to or greater than a predetermined value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground radar device used for a non-cutting drilling method.

[0002]

2. Description of the Related Art Recently, in response to a demand for burying transmission and distribution lines underground, an economical construction method for forming a tunnel for accommodating electric lines underground is required. Conventionally, a non-cutting drilling method has been developed as an inexpensive method for forming a small-diameter tunnel in the ground without performing cutting from the ground.

[0003] According to the non-cutting drilling method, a flexible long body called a rod has a diameter of 50 to 60 m.
An excavator with a small diameter of about m is installed. An excavating blade is attached to the tip of the excavator at an angle. Then, by applying a rotational force and a propulsive force from a rotation / propulsion mechanism installed on the ground to the excavator at the tip via a rod, excavation of earth and sand is performed by a drill blade attached to the tip of the excavator,
A small-diameter tunnel is formed in the ground. Rods are added as the excavation progresses, and the tunnel is extended forward.

A tunnel formed by the above method is generally formed substantially horizontally with respect to the ground surface. When this small-diameter tunnel is completed, a back reamer is attached to the forefront of the added rod, replacing the excavator. Then, while the rod is retracted, the small-diameter tunnel is widened by the back reamer to form a final-diameter tunnel. At this time, the problem was that when the excavator formed a small-diameter tunnel, it did not become an obstacle, but when the back reamer widened it, it became an obstacle, for example, underground objects such as gas pipes and water pipes. That it may be present.

[0005] If an obstacle is found during widening by the back reamer, the operation must be repeated from the formation of a small-diameter tunnel by the excavator, resulting in a large loss in time and labor. Therefore, when a small-diameter tunnel is formed by an excavator, an underground radar device is attached to the tip side of the excavator to detect obstacles, and a small-diameter tunnel is removed from the formed obstacle by a predetermined distance necessary for widening by a back reamer. Measures have been taken to change the course of the excavator so as to keep it away.

In such an underground radar device, a plurality of antenna elements are formed along the outer peripheral surface on the tip side of an excavator when it is mounted on the back side of a digging blade (Japanese Patent Laid-Open No. 8-278371). Case (Japanese Unexamined Patent Application Publication No. 2000-147137)
No.). In the latter case, a non-directional combined antenna is formed by combining the directivities of a plurality of antenna elements. The received signals obtained by these underground radar devices pass through the rod from the excavator (Japanese Unexamined Patent Publication No.
000-204883) or through a wireless transmission path underground to a signal processing / image display device installed on the ground.

[0007]

Among the above-mentioned conventional underground radar devices, those which transmit the received signal to a signal processing / display device on the ground through a rod are provided between adjacent rods which are detachably connected. There is a problem that a broadband transmission path for the reception signal of the middle radar device must be formed, and the manufacturing cost of the rod increases. In the case of transmitting signals received by an underground radar device to a device on the ground through a wireless transmission path underground, high-speed signal transmission becomes difficult because the attenuation of radio waves propagating underground increases at higher frequencies. ,
There is a problem that the processing and display of the received signal cannot follow the digging speed of several tens of cm per second.

Accordingly, an object of the present invention is to provide an underground radar for a non-cutting drilling method in which signal processing and display can follow the excavating speed of an excavator without increasing the cost of manufacturing a rod. Is to do.

[0009]

An underground radar apparatus for non-cutting drilling method according to the present invention which solves the above-mentioned problems of the prior art is an underground excavator which is moved in the direction of the rotating shaft while rotating in the ground. A plurality of antenna elements are arranged along the outer peripheral surface on the tip side of the antenna, and the characteristics of each antenna element are combined to form a combined antenna with omnidirectional characteristics around the rotation axis. It is a radar device.

The underground radar apparatus according to the first aspect of the present invention is such that the delay amount at the time of receiving the received signal of the combined antenna increases or decreases substantially monotonically over a predetermined length in the moving direction, and When the amount of change of the delay amount in the moving direction is equal to or more than a predetermined value, an estimation / notification for estimating that the received signal includes a reflected wave from a reflecting object and transmitting a notification signal to that effect to the ground apparatus. Means. As a result, information that has been significantly compressed by the addition of the estimation function is transmitted to a terrestrial device instead of a broadband received signal.

The underground radar apparatus according to the second aspect of the present invention is characterized in that the delay amount at the time of reception of the reception signal of the combined antenna over a predetermined length in the moving direction generally increases monotonically, and then increases. An estimating / notifying means for estimating that the received signal includes a reflected wave from a reflecting object and transmitting a notification signal to that effect to the ground equipment when the amount of change of the delay amount in the moving direction is equal to or more than a predetermined value; , So that greatly compressed information based on the addition of the estimation function is transmitted to a device on the ground.

According to the non-cutting drilling method of the present invention, a plurality of antenna elements are arranged along the outer peripheral surface on the tip side of an underground excavator which is moved in the direction of the rotation axis while rotating in the ground. An underground radar device is provided in which a combined antenna having an omnidirectional characteristic is formed around the rotation axis by combining the characteristics of the elements. The underground radar device analyzes the reception signal of the omnidirectional synthetic antenna and estimates that the reception signal includes a reflected wave from a reflecting object, and transmits a notification signal to that effect to the ground device. Estimation / notification means to perform Further, the ground apparatus having received the notification signal includes means for reducing the moving speed of the underground excavator and transmitting only one received signal of each of the antenna elements to the underground radar apparatus.

[0013]

According to a preferred embodiment of the underground radar apparatus of the present invention, the above estimation is performed based on the arrangement of pixels on a virtual B-scope display screen, so that the accuracy of the estimation is improved. It is configured to increase.

According to another preferred embodiment of the underground radar apparatus of the present invention, the notification signal of the estimation result is transmitted by radio to the ground apparatus under the ground, thereby reducing the manufacturing cost of the rod. It is configured to be realized.

According to still another preferred embodiment of the underground radar apparatus of the present invention, the reception of the reception signal is performed while expanding the time axis so that a highly accurate B-scope signal is obtained. It is configured.

According to a preferred embodiment of the non-cutting drilling method of the present invention, the underground excavator is configured to be retracted by a predetermined distance before the moving speed is reduced.

[0017]

FIG. 2 is a view showing the configuration of an antenna constituting an underground radar apparatus for a non-cutting drilling method according to an embodiment of the present invention, together with the relationship with an excavator. FIG. 2 (A) shows a cylindrical excavator. FIG. 2B is a side view showing the structure of FIG. 1 with a part thereof removed, and FIG. 2B is a cross-sectional view of the structure taken along a plane perpendicular to the axis of the excavator.

Rotational force and propulsion force are transmitted to a cylindrical excavator P from a power unit installed on the ground via a rod (not shown). As a result, when the excavator P is propelled forward while rotating, a metal excavating blade BL fixed to the tip of the excavator P scrapes the soil in front of the excavator P to form a tunnel behind.

Inside the excavator P, four transmitting / receiving antennas AT1 to AT4 are installed at an angular interval of 90 ° in the circumferential direction of the excavator P. Each transmission / reception antenna is composed of a transmission-only antenna and a reception-only antenna arranged along the axial direction of the excavator P. Each of the four transmitting / receiving antennas AT1 to AT4 has a directivity of transmitting a pulse signal only forward and receiving only a reflected wave generated by a forward reflecting object. During excavation, pulse signals are simultaneously transmitted from the four transmitting / receiving antennas AT1 to AT4, and the reflected waves received by the respective transmitting / receiving antennas are combined to form a virtual single omnidirectional transmitting / receiving antenna AT. Function as

FIG. 3 is a functional block diagram showing the configuration of the main part of the underground radar for the non-cutting drilling method of the above embodiment, wherein 1 is a transmission trigger generation circuit, 2 is a transmission circuit, and 3 is a transmission circuit.
Is a transmission antenna selector, ATT1 to ATT4 are transmission-only antennas constituting transmission and reception antennas AT1 to AT4, A
TR1 to ATR4 are reception-only antennas constituting transmission and reception antennas AT1 to AT4, 4 is a reception antenna selection unit,
Is a reception circuit, 6 is an A / D conversion circuit, 7 is a control / data processing unit, 8 is a transmission / reception circuit, and AT0 is a transmission / reception antenna.

The control / data processing section 7 transmits a control signal to the transmitting antenna selecting section 3 and the receiving antenna selecting section 4 in accordance with a command from the ground, which will be described later, to virtually control the antenna portion of the underground radar apparatus. Or a single omnidirectional transmitting / receiving antenna or a group of a plurality of directional antennas.

During normal excavation work, the four transmitting / receiving antennas AT1 to AT4 function as virtual omnidirectional transmitting / receiving antennas. That is, the transmission antenna selection unit 3 selects all of the transmission-dedicated antennas ATT1 to ATT4 constituting the transmission / reception antennas AT1 to AT4 based on a command from the control / data processing unit 7, and transmits the transmission signals generated by the transmission circuit 2 to each of them. Supply pulse signal. As a result, transmission pulse signals are simultaneously output from the four transmitting / receiving antennas AT1 to AT4 into the ground. At the same time, the reception antenna selection unit 4 connects all the reception-only antennas ATR1 to ATR4 of the four transmission / reception antennas AT1 to AT4 to the reception circuit 5. As a result, the transmitting and receiving antennas AT1 to AT
4 are combined in the receiving circuit 5.

When an obstacle is detected by the virtual single omnidirectional transmitting / receiving antenna, the excavator is once moved backward, and in accordance with a later-described command from the ground,
After an appropriate one of the directional transmitting / receiving antennas AT1 to AT4 is selected, an obstacle is searched for using the selected directional transmitting / receiving antenna while moving the excavator at low speed.

FIG. 4 shows an example of a received signal waveform of a virtual single omnidirectional transmitting / receiving antenna AT. The upper rectangular pulse signal is a transmission trigger signal T of a fixed period generated by the transmission trigger generation circuit 1. A transmission pulse signal is generated in the transmission / reception circuit 2 in synchronization with the transmission trigger signal T, and a pulse-like signal is transmitted from the omnidirectional transmission / reception antenna AT underground. A certain time τ from the transmission time
The received signal R is received by the transmission / reception antenna AT with a delay of only As described above, this reception signal R is actually a combination of reception signals of the reception-only antennas of the four transmission / reception antennas AT1 to AT4.

The delay time τ from the transmission trigger signal T to the point at which the received signal R is output is determined by the fact that the radio wave transmitted from the transmitting / receiving antenna AT into the ground propagates to the reflecting object, becomes a reflected wave, and follows the reverse path. This is the time required for reception by the transmission / reception antenna AT, that is, the time required for the transmitted radio wave to travel under the ground required to reciprocate between the transmission / reception antenna AT and the reflecting object. Therefore, this delay time τ
Is divided by the propagation speed of the radio wave in the ground, and is halved, the distance from the transmitting / receiving antenna AT to the reflecting object is calculated.

The amplitude of the received signal shown in FIG.
What is displayed on the cathode ray tube with the elapsed time on the horizontal axis is the A-scope display screen. On the other hand, the B-scope display screen is obtained by converting the amplitude of the received signal R shown in FIG. 4 into a luminance signal, displaying the time axis on the vertical axis and the moving distance of the antenna on the horizontal axis on the CRT. In this B scope display, as shown in FIG. 5, a ship emits an ultrasonic signal toward the bottom of the water at a constant period while moving at a constant speed, and displays a received signal including a reflected wave on a CRT. Suitable for going.

That is, in the example of FIG. 5, as shown in FIG. 6, a display screen which reflects the underwater situation well is obtained. In this B-scope display screen, the vertical axis is set downward and is referred to as a depth distance measured from the water surface. In the underground radar device for the non-cutting drilling method according to the present embodiment, the concept of the B scope display screen described above is used for detecting a reflecting object.

FIG. 7 shows a case where the virtual single omnidirectional antenna AT attached to the excavator P advances in the soil in the direction of the arrow in the figure as the excavation progresses. I have. Normally, since the tunnel is formed substantially parallel to the ground, the traveling path of the virtual omnidirectional antenna AT is also substantially parallel to the ground. FIG. 7 illustrates a case where an embedded object X such as a gas pipe or a water pipe exists above the traveling path of the omnidirectional antenna AT so as to cross the traveling path.

In this case, as the position of the omnidirectional antenna AT changes as a, b, c... As shown in the figure, the distance between the omnidirectional antenna AT and the buried object X becomes La,
Lb, Lc,... Along with this, the delay time τ of the reflected wave included in the received signal decreases, and the distance Lc starts to increase again with the minimum value Lc.

Assuming that the situation of changes in the positions of the underground object X and the omnidirectional antenna illustrated in FIG. 7 is to be a B-scope display screen, a virtual B-scope display screen as shown in FIG. Is obtained. An image U in which the first peak portion of the reflected wave generated in the buried object X as illustrated in FIG. 1 is connected to the moving direction of the antenna appears as an image U, and the next peak portion that appears slightly later is referred to as the antenna U. The image connected in the moving direction is displayed as an image V. It is displayed as if the depth distance is the shortest immediately below the buried object X, and as the distance from this point increases and decreases.

In the waveform diagram of FIG. 4, the transmission trigger signal T
Is about 50 nsec, the farthest point that can be detected is a value obtained by multiplying the upper limit value of the one-way propagation time of 25 nsec by the propagation speed of radio waves in the ground. The propagation speed of radio waves in the ground is the value obtained by dividing the propagation speed in a vacuum of 3 × 10 ⁸ m / sec by the square root of the relative permittivity εs of the earth and sand in the ground. The specific induction rate of soil under the ground increases as the moisture content of the soil increases, and varies over a range of about 10 to 100. As a result, the farthest detectable distance is 2.
The value ranges from 5 m to 0.75 m.

The transmission of the pulse signal into the ground and the reception of the reflection signal are performed while expanding the time axis. This expansion of the time axis is achieved by transmitting a transmission signal from the transmission circuit 2 in a fixed cycle in synchronization with the transmission trigger signal T, and accumulating the reception circuit 5 by a certain minute amount with respect to the fixed transmission timing. This is performed by sampling the received signal while delaying it. In this embodiment, by setting the magnification of the time axis to 10 ⁴ , 1
Reception and is repeated with the transmission of approximately 5msec over 10 ^four pulse signals in order to obtain the pieces of data. As for the improvement of the measurement accuracy by the expansion of the actual time, if necessary, refer to Japanese Patent Publication No. 7-69427 related to the earlier application of the present applicant.

The A / D conversion circuit 5 enlarges the time axis by 10,000 times and outputs a digitized received signal.
The received signal is composed of 500 to 1000 sampling points arranged at regular intervals on a time axis of 50 nsec required for reciprocation of radio waves. In the B scope display screen of FIG. 1 based on the received signal, 200 lines are arranged on the horizontal axis for every 4 m of antenna movement distance. One line is two
Corresponding to a moving distance of cm.

The control / data processing section 7 assigns “1” if the level of each sampling point of the received signal received from the A / D conversion circuit 6 is higher than a predetermined value, and assigns “0” if the level is lower than the predetermined value. Thus, the received signal is binarized. As a result, the virtual B scope display screen of FIG. 1 is converted into an array of pixels as illustrated in FIG. The control / data processing unit 7 tracks the connectivity of the pixels obliquely downward on the virtual B-scope display screen as illustrated in FIG.

The tracking of the connectivity of the pixels obliquely downward is as follows.
First, the processing is performed from the right line to the nearest left line. When the connectivity of the pixels obliquely downward is detected, the detection of the connectivity of the pixels obliquely downward toward the leftmost adjacent line is continued one after another. Such detection of connectivity between adjacent pixels is performed according to an appropriate method used in the technical field of image processing such as pattern recognition. In this manner, the lower left pixel s is shifted from the upper right pixel a to the lower left pixel s.
Is detected.

The control / data processing unit 7 calculates a continuous reception distance Δd in the antenna moving distance direction from the number of connected pixels in the line direction, and determines whether the calculated continuous reception distance is equal to or greater than a predetermined value. judge. If Δd is equal to or more than a predetermined value, a continuous distance Δz in the depth direction is calculated from the number of connected pixels in the sampling point direction, and whether or not this is equal to or more than a predetermined value is calculated. If the calculated continuous distance Δz is equal to or greater than the predetermined value, the control / data processing unit 7 determines that the presence of a reflected wave from the reflecting object has been detected.

Virtual omnidirectional transmitting / receiving antenna AT
Has omnidirectionality around the rotation axis of the excavator, but has directivity in the traveling direction of the excavator, that is, the moving direction of the transmitting / receiving antenna AT. For this reason, in the example of FIG.
When the transmitting / receiving antenna AT is separated from the buried object X to some extent, the receiving sensitivity becomes lower than the noise level and the receiving becomes impossible.
It is assumed that the directivity of the transmitting / receiving antenna AT with respect to the moving direction is 45 ° forward and rearward, respectively, and in the example of FIG. 7, the direction of the buried object X as viewed from the position e of the transmitting / receiving antenna is exactly 45 ° rearward. . In this case, Le = √2Lc.

The pixel a and the pixel s in FIG.
If the reflected waves are obtained at the positions c and e of the transmitting and receiving antenna AT, the difference ΔZ between the depth distances of the pixels a and s is as follows: ΔZ = Le−Lc = (√2-1) Lc ≒ 0.41Lc, From this, the following equation is obtained. ΔZ / Lc ≒ 0.41

As described above, in consideration of the directivity of the transmitting / receiving antenna AT in the moving direction, in this example, the value of ΔZ is set so that the depth distance of the pixel s becomes √2 of the depth distance of the pixel a. . If the value of Δz is less than the predetermined value, it is estimated to be a reflected wave from the ground surface or a known underground object extending in the moving direction of the excavator, and no notification is made. The value of Δd is set to an appropriate value, for example, Δd = αLc (α is a proportional constant).

When detecting the reflection object, the control / data processing section 7 transmits a signal notifying the fact to the ground via the transmission / reception circuit 8 and the transmission / reception antenna AT0. The notification signal transmitted underground is an FM signal, which propagates through the ground and is received by a receiver installed on the ground. The notification signal received by the receiver is demodulated and generates an alarm sound by a buzzer or is displayed on a screen.

The operator of the excavator receiving the notification signal,
After retracting the excavator, the transmitting and receiving antennas AT1 to AT1
A command to select only one of the AT4s is controlled from the terrestrial transceiver via the transmitting / receiving antenna AT0 and the transmitting / receiving circuit 8.
The data is transmitted to the data processing unit 7. Upon receiving this command, the control / data processing unit 7 transmits and receives the directional transmission / reception antennas AT1 to AT
Select an appropriate one from the four. Thereafter, an obstacle is searched for using the selected directional transmission / reception antenna while moving the excavator forward at a low speed.

The received signal (A scope signal) received by the selected transmitting / receiving antenna is transmitted underground from the transmitting / receiving antenna AT0 via the A / D conversion circuit 6, the control / data processing unit 7, and the transmitting / receiving circuit 8, Received by the ground transceiver. In this search operation using the directional antenna, the excavator, and thus one selected directional antenna, is advanced at a low speed, and the A-scope signal is transmitted by the low-speed data transfer under the ground, and the rotation of the excavator is performed. Sent together with the angle signal to ground transmission and reception. The ground transmission / reception device receives the signal and processes the A scope signal and the rotation angle signal of the excavator to display the B scope on the ground display device. The position of the obstacle is confirmed by observing the B scope display of the operator.

As described above, by assuming that the transmitting / receiving antenna moves away from the reflecting object in the case of FIG.
The configuration in which the depth distance monotonically increases over the moving distance of the antenna equal to or more than the predetermined value, and the presence of the reflecting object is detected when the increment is equal to or more than the predetermined value has been exemplified. Conversely, by assuming a case where the transmitting and receiving antenna approaches the reflecting object in the case of FIG. May be configured to detect the presence of a reflecting object because is greater than or equal to a predetermined value. In this case, it is possible to detect the position of the reflecting object by selecting one of the antenna elements and moving the excavator forward at a low speed without retreating the underground excavator once.

Alternatively, by combining the above two and assuming a case where the transmitting and receiving antenna approaches the reflecting object and then separates, the depth distance monotonically increases and then monotonically decreases over the moving distance of the antenna equal to or more than the predetermined value. Then, it is also possible to adopt a configuration in which the presence of a reflecting object is detected based on the fact that the increment or decrement is equal to or more than a predetermined value.

Further, the configuration in which the presence of the reflecting object is determined based on the arrangement state of the pixels on the virtual B scope display screen has been exemplified. However, without using such a concept of a virtual B-scope display screen, a configuration in which the presence of a reflecting object is estimated from a state in which a delay amount at a rising point detected from a received signal changes in a moving direction of an antenna. Can also be adopted.

[0046]

As described above in detail, the underground radar apparatus for the non-cutting drilling method of the present invention has a predetermined rule that the delay amount at the time of receiving the received signal of the combined antenna changes in the moving direction. Because it is a configuration that adds the function of estimating the presence of a reflective object based on whether or not it is satisfied and notifying the ground device of that, a significantly compressed notification signal is transmitted to the ground device instead of raw data Is done. As a result, it is possible to provide an underground radar for the non-cutting drilling method in which the signal processing and display can follow the excavating speed of the excavator without increasing the manufacturing cost of the rod.

According to the preferred embodiment of the present invention, the existence of the reflective object is estimated by using the inspection method for the arrangement state of the pixels on the virtual B-scope display screen. There are advantages such as that part of existing image processing and recognition software can be used.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram exemplifying a part of a virtual B-scope display screen created from a received signal of an underground radar for a non-cutting drilling method according to an embodiment of the present invention.

FIG. 2 is a partial cutaway view (A) and a cross-sectional view (B) showing a configuration of an antenna portion of the underground radar device of the embodiment together with an excavator.

FIG. 3 is a functional block diagram showing a configuration of the underground radar device of the embodiment.

FIG. 4 is a diagram illustrating a waveform of a reception signal received by a transmission / reception antenna of the underground radar device.

FIG. 5 is a conceptual diagram illustrating a state of underwater exploration suitable for displaying a B scope virtually used in the embodiment.

FIG. 6 is a conceptual diagram illustrating a B-scope display screen as a result of the underwater search.

FIG. 7 is a conceptual diagram illustrating a state of searching for an underground object by the underground radar device of the embodiment.

FIG. 8 is a conceptual diagram illustrating a part of a virtual B-scope display screen created from a quantized reception signal of the underground radar device of the embodiment.

[Explanation of symbols]

U, V Reflected object image P Underground excavator BL Drilling blade AT0 Transmitting and receiving antenna AT1 to AT4 Directional transmitting and receiving antenna ATT1 to ATT4 Directional transmitting and receiving antenna transmitting antenna ATR1 to ATR4 Directional transmitting and receiving antenna receiving antenna 1 transmission trigger generation circuit 2 transmission circuit 5 reception circuit 7 control / data processing unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16L 1/02 Z (72) Inventor Morio Suzuki 1121-5 Kashima, Hachioji-shi, Tokyo Junes Kashima 408 F-term (Reference) 2D054 AC18 5J070 AB01 AC03 AD05 AE11 AH31

Claims (7)

[Claims] A plurality of antenna elements are arranged along the outer peripheral surface on the tip side of an underground excavator that is moved in the direction of the rotation axis while rotating in the ground, and the characteristics of each antenna element are combined. In the underground radar apparatus of the non-drilling drilling method in which a synthetic antenna having an omnidirectional characteristic is formed around the rotation axis, the delay amount at the time of receiving the reception signal of the synthetic antenna is changed in the moving direction of the underground excavator. When the amount of change in the moving direction of the delay amount is greater than or equal to a predetermined value, the reflected signal from the reflecting object is included in the received signal. An underground radar for a non-drilling drilling method, comprising: an estimating / notifying means for estimating that the drilling is performed and transmitting a notification signal to that effect to the ground equipment. 2. A plurality of antenna elements are arranged along the outer peripheral surface on the tip side of an underground excavator that is moved in the direction of the rotation axis while rotating in the ground, and the characteristics of each antenna element are combined. In the underground radar apparatus of the non-drilling drilling method in which a synthetic antenna having an omnidirectional characteristic is formed around the rotation axis, the delay amount at the time of receiving the reception signal of the synthetic antenna is changed in the moving direction of the underground excavator. To a predetermined length or more and then increase monotonically and then increase, and when the amount of change in the moving direction of the delay amount is equal to or more than a predetermined value, the received signal includes a reflected wave from a reflecting object. An underground radar for non-cutting drilling method, comprising: an estimating / notifying means for estimating that the drilling is to be performed and transmitting a notification signal to that effect to the ground equipment. 3. The underground radar for a non-cutting drilling method according to claim 1, wherein the estimation is performed based on a state of an arrangement of pixels on a virtual B-scope display screen. . 4. The underground radar for a non-drilling drilling method according to claim 1, wherein the notification signal is transmitted to the ground device wirelessly in the ground. 5. The underground radar according to claim 1, wherein the reception signal is received while expanding a time axis. 6. A plurality of antenna elements are arranged along the outer peripheral surface on the tip side of an underground excavator which is moved in the direction of the rotation axis while rotating in the ground, and the characteristics of each antenna element are synthesized. In an uncut drilling method including an underground radar device in which an omnidirectional synthetic antenna is formed around the rotation axis, the underground radar device analyzes a reception signal of the omnidirectional synthetic antenna. The estimation and notification means for estimating that the received signal includes the reflected wave from the reflecting object and transmitting a notification signal to that effect to the ground apparatus, the ground apparatus receiving the notification signal A non-cutting drilling method, comprising: means for reducing a moving speed of an excavator and transmitting only one received signal of each of the antenna elements to the underground radar device. 7. The non-cutting drilling method, wherein the underground excavator is retreated a predetermined distance before the moving speed is reduced.