JPH02257082A - Underground searching device - Google Patents

Abstract

PURPOSE:To improve working efficiency by detecting the position of an object to be searched in accordance with the propagation time of reflected waves, the moving distance of a moving truck obtd. at every point of the time when a reception completion signal is outputted and order in which transmission and reception operation signals are outputted. CONSTITUTION:The reception completion signals and echo signals outputted from respective signal receivers 1b to 8b and in addition, the position X of the moving truck 11 detected by a position detector 16 and the input operation signal of a keyboard input signal 19 are applied to a CPU 17. The CPU 17 controls a timing trigger generator 13 overall in accordance with the reception completion signals outputted from the receivers 1b to 8b and makes the processing to form the two-dimensional sectional image signals indicating the two-dimensional sectional image in the ground in accordance with the echo signals outputted from the receivers 1b to 8b and the output of the position detector 16. The CPU acts to output the two-dimensional sectional image signals to a TV monitor 18. The TV monitor 18 displays the two-dimensional sectional image in the ground on a display screen 18 in accordance with the above- mentioned two-dimensional sectional image signals.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an underground exploration device that non-destructively detects the position of underground objects to be explored, such as water pipes and cables buried underground. In particular, the present invention relates to an underground exploration device suitable for use in exploring a wide exploration area such as cavities that occur under the road surface or buried and hidden dangerous objects, or exploration of targets that require exploration.

[Conventional technology]

2. Description of the Related Art Hitherto, the present applicant has proposed various underground object exploration devices that can detect the position of underground objects with high precision and a simple configuration in a short time.

The structure and operation of this type of device are roughly as follows.

That is, one set of a transmitter and a receiver is mounted on a movable trolley, and the movable trolley is moved along a search line. During this time, a transmitter emits radio waves underground at each point on the exploration line, and a receiver receives the radio waves reflected by underground objects.

On the other hand, a display means is provided for displaying an echo image of the underground object using the depth direction of the underground object and the moving direction of the movable cart as parameters.

Then, the transmitter/receiver at each point on the exploration line
The echo image of the underground object is displayed on the display means based on the reception timing (propagation time of the reflected wave).

In this case, the echo image is formed as a hyperbolic echo image on the display surface of the display means due to the spread of the transmitted radio waves.

Therefore, an operation is performed to superimpose a hyperbolic pseudo echo image on this echo image. This is a technique called the Cubfitting method, which has already become known through the publication of a patent application filed by the present applicant. As a result, if the two echo images overlap, the apex of the echo image and the spread of the aperture can be determined from the information of the pseudo echo image, and the information indicating the apex position and the spread of the aperture can be used to determine the underground radio wave propagation. Calculate speed vg. Once vg has been calculated, the position of the underground object is calculated based on the relationship with the propagation time information at an arbitrary position.

[Problem to be solved by the invention]

Incidentally, in recent years, many cavities have appeared under the road surface, which frequently causes ground subsidence. Therefore, it is desired to develop an underground exploration device that can efficiently explore the above-mentioned cavities.

Unlike gas pipes, water pipes, etc., the locations of dangerous substances such as explosives buried in cavities or hidden beneath the earth's surface cannot be predicted in advance. It is necessary to do it.

However, when exploring the above-mentioned cavities etc. with the above-mentioned conventional exploration device, the exploration width with one set of transmitter/receiver is about 60 cm at most. It is necessary to perform underground exploration by moving not only on a line but also on many different exploration lines.

This significantly impairs the operating efficiency (time) of underground exploration.

Therefore, in order to expand the search range of a pair of transmitters and receivers,
Although it is possible to increase the size of the receiving antenna, this method has not been adopted or implemented because the resolution of the received echo image is significantly reduced and accurate two-dimensional cross-sectional images cannot be obtained.

Furthermore, it is conceivable to prepare a plurality of movable carts on which transmitter/receiver sets of ] are mounted and conduct the exploration by simultaneously moving these plurality of movable carts along different exploration lines, but in this case, The reflected waves of the radio waves emitted by the transmitters of each mobile carriage interfere with each other, and the receiver cannot identify which reflected wave was transmitted by the transmitter of which mobile carriage. Therefore, similar to the above, it is not possible to perform accurate exploration, so it has not been adopted or implemented.

The present invention was developed in view of these circumstances, and it is extremely efficient and effective for detecting targets that require a wide exploration area, such as cavities under the road surface or dangerous objects buried and hidden beneath the ground surface. The purpose is to provide an underground exploration device that can perform accurate exploration.

[Means to solve problems]

Therefore, in this invention, the reflected wave of the radio wave emitted underground from the transmitter mounted on the movable trolley tower by the object to be investigated is received by the receiver mounted on the movable trolley tower, and the propagation time of the reflected wave is used to determine the In a radar-based underground exploration device for detecting the position of a target, a plurality of sets of the transmitter/receiver are arranged in parallel along the interior direction of the mobile trolley, and the plurality of sets of transmitters/receivers are sequentially activated. means, specifically, each of the plurality of sets of transmitting/receiving devices includes a transmitting/receiving operation means for emitting the radio wave and receiving the reflected wave only while a transmitting/receiving operation signal is input; and a reception completion signal output means for outputting a reception completion signal when reception of the reflected wave is completed, and when each transmitter/receiver of the plurality of sets of transmitters/receivers outputs the reception completion signal. , stop outputting the transmitter/receiver operation signal to the transmitter/receiver that outputs the reception completion signal, and follow the preset order for the transmitter/receiver of the next set of the transmitter/receiver. and transmitting/receiving operation signal output means for sequentially outputting the transmitting/receiving operation signals.

Then, the position of the object to be searched is detected based on the output of each of the plurality of receivers. Specifically, the propagation time of the foul wave is increased each time each transmitter/receiver of the plurality of sets of transmitters/receivers outputs the reception completion signal;
Based on the moving distance of the movable cart obtained each time the reception completion signal is output, and the order of outputting the transmitting/receiving operation signals, The position of the exploration target is detected.

[Effect]

That is, the transmission/reception operation signal output means sequentially outputs transmission/reception operation signals to each of the plurality of sets of transmitters/receivers in a preset order in response to the output of the reception completion signal.

On the other hand, the transmitter/receiver operates only while the transmitter/receiver operation signal is input, and outputs a reception completion signal when reception is completed.

Therefore, transmission/reception is performed at the - transmitter/receiver, and no transmission/reception is performed at the other transmitter/receiver until reception is completed. Therefore, mutual interference of radio waves does not occur between the plurality of transmitters and receivers, and the receiver can identify that the reflected wave is caused by the transmitter of the set of receivers.

In this way, when transmitting/receiving operations of multiple sets of transmitting/receiving devices are performed sequentially, the propagation time of the reflected wave and the movement at each point of each transmitting/receiving operation are determined at the end of each transmitting/receiving operation (when the reception completion signal is output). Since we can obtain the distance traveled by the trolley,
Based on these data and the order of outputting transmission/reception operation signals to multiple sets of transmitters/receivers, it is possible to obtain propagation time data corresponding to the travel distance for each of multiple sets of transmitters/receivers. can.

Therefore, each installation position (Y coordinate), moving distance (X coordinate), propagation time, or propagation distance (Z
Since the correspondence between the coordinates and coordinates is specified, the movement plane (X-Y plane) of multiple pairs of transmitters and receivers, that is, the correspondence between multiple pairs of transmitters and receivers, can be determined using the conventional radar-based underground exploration method. It is possible to detect the position Z of the object to be searched under the search area whose width is the width of the parallel arrangement. Specifically, a two-dimensional underground cross-sectional image is formed under each movement line of a plurality of sets of transmitters and receivers.

By displaying all of the underground two-dimensional cross-sectional images for each set, the position of the object to be investigated under the exploration area with the exploration width equivalent to the width of the parallel installation of multiple sets of transmitters/receivers can be determined using one of the movable trolleys. It can be detected by only one movement.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an external perspective view showing an example of an underground exploration device according to the present invention.

In the embodiment, it is assumed that a cavity CV occurring under the road RD surface is to be explored.

The underground exploration device 10 shown in the figure forms a cross-sectional image under the road RD surface based on the principle of a normal electromagnetic wave reflection method. It consists of a transmitter/receiver section 14.

That is, the transmitter/receiver unit 14 is installed at the front of the mobile cart 11.
The transmitting/receiving units I-1, 2B, 4, 5, 6.7 are placed in a unit storage box 15 whose length in the longitudinal direction is approximately the length of one lane on one side of the road RD. and 8 are housed in a movable trolley] 8 sets are arranged side by side along the interior direction of 1.

Furthermore, the CPU unit section 12 and the timing trigger generator 13 are fixedly mounted on the mobile cart 1.

The wheels of the movable trolley 11 are equipped with position detectors 16 (for example, pulse encoders and counters) that generate 11 pulses every time the trolley 11 moves a unit distance to detect the position (traveling distance) of the movable trolley 11. ) is attached. Therefore, when the movable cart 1 moves along the X-axis direction, successive X-coordinate positions X can be detected.

Figure 2 shows the position detector 1-6, CPU unit 2, timing trigger generator j3, and transmission/reception units 1 and 2.
, 3, 4, 5, 6.7, and 8. FIG.

The transmitting/receiving unit 1 includes a transmitter]a that emits radio waves toward a hollow CV in the ground, a transmitting antenna]21A, a receiver]b that receives reflected waves from the hollow CV, and a receiving antenna IB. configured and other shipping/
Receiving unit 2. ..., 8 is also the same transmitter 2a, ...
.,8a and transmitting antenna 2A...8A, receiver 2b,...,8b and receiving antenna 2B,...
8B.

The timing trigger generator 13 performs a transmitting/receiving operation for each of the transmitting/receiving units 1 to 8 in accordance with the order described later. It outputs a signal.

On the other hand, in the transmitting/receiving units 1 to 8, only while the above transmitting/receiving operation signal is input manually, each transmitter]a to 8a and each receiver 1b to 8b respectively operate to emit the above radio wave. and a mechanism for receiving the reflected waves.

Each of the receivers 1b to 8b outputs a reception completion signal indicating that the reception has been completed when the reception of the reflected wave is completed, and converts the received reflected wave signal into a received signal by an A/D converter (not shown). ] 3 Convert into a digital signal (hereinafter referred to as an echo signal) indicating the arrival time and reception strength, and apply these reception completion signals and echo signals to the CPU 17 of the CPU unit section 12.

The CPU unit section 12 includes, in addition to the CPU 7 described above, a TV monitor 8 and a keyboard input device 9.

In addition to the reception completion signals and echo signals output from each receiver 1b to 8b, the CPU 17 also receives the position detector 16.
The position X of the movable trolley 11 detected at and the input operation signal of one keyboard input device are added.

Then, the CPU 17 generates a signal from the timing trigger generator 13 based on the reception completion signal outputted from the receivers b to 8b.
It also performs processing to create a two-dimensional cross-sectional image signal indicating a two-dimensional cross-sectional image of the underground based on the echo signals output from the receivers 1b to 8b and the output of the position detector 16. , serves to output this two-dimensional cross-sectional image signal to the TV monitor 1-8.

The TV monitor 18 displays a two-dimensional cross-sectional image of the underground on a display screen 1.8a (FIG. 1) based on the two-dimensional cross-sectional image signal.

When the two-dimensional cross-sectional image is displayed on the display screen 18a, the operator performs a necessary keyboard input operation on the keyboard input device 19, and based on the operation, the two-dimensional cross-sectional image is displayed via the CPU 17 using the two-dimensional cross-sectional image signal. The echo image appearing on the screen 18a and the pseudo echo image which is different from the image based on this image signal are superimposed on the display screen 18a, and the position of the underground cavity Cv is detected.

The procedure for exploring an underground cavity CV using this device in the above configuration will be explained with reference to FIG. 5, but before that, the specific circuit configuration and operation of the timing trigger generator] 3 will be explained. .

That is, as shown in FIG. 3, the timing trigger generator 13 includes a termination signal decoding section 20 which manually inputs reception completion signals outputted from the receivers 1b to 8b through the CPU 17 and decodes the reception completion signals; The decoding section 20
The timing trigger generating section 22 is constructed around a Johnson counter 21 which inputs count pulses outputted from the counter to the count input C.

AND circuit 3 of timing trigger generation section 22] 32.3
The output signals of 3, 34, 3, 36.
Receiving units l-1, 2, 3゜4.5, 6.7 and 8
are added to each.

FIG. 4 is a time chart showing the operation of the timing trigger generator 13.

That is, the reception completion signal (logical "]" is now output from the receiver 1b.
``level'' is applied to the end signal decoder 20 as a one-shot pulse, the rising edge of this one-shot pulse is captured and output from the AND circuit 31 as a logic ``1'' level transmission/reception operation signal (this is the transmission/reception operation signal). - Added to the receiving unit]) (see arrow B in the same figure), and the AND circuit 32 outputs the logic ゛]''
The level transmitting/receiving operation signal is raised and outputted, and then applied to the next transmitting/receiving unit 2 (see arrow E in the figure).

Next, when a one-shot pulse (reception completion signal) is similarly output from the receiver 2b, the transmitting/receiving operation signal applied to the transmitting/receiving unit 2 falls and (
(See arrow F in the same figure) A transmitting/receiving operation signal is output from the AND circuit 33 and is applied to the next transmitting/receiving unit 3 (see arrow G in the same figure).

Thereafter, in the same way, when a one-shot pulse (reception completion signal) is output from the receivers 1b to 8b, the transmission/reception units 1 to 8 to which the receivers 1b to 8b that output the reception completion signal belong At the same time as lowering the currently output transmitting/receiving operation signal, the next transmitting/receiving unit 1
.about.8, the operation of raising and outputting the transmitting/receiving operation signal is repeatedly executed.

Assuming that the above-mentioned operation is performed by the timing generator] 3, the processing procedure performed by the CPU 17 will be described below with reference to the flowchart shown in FIG. 5.

As shown in FIG. 1, it is assumed that the movable cart 11 is moved at a constant speed (2) in the X-axis pressure direction by a drive motor (not shown). Also, for convenience of explanation below, the transmitting/receiving unit hn (n=1 to 8) is an nth set of transmitting/receiving devices,
The receivers nb (n=1 to 8) are respectively referred to as the n-th set of receivers.

First, as shown in Fig. 4, the period in which all eight sets of transmitting/receiving units perform one-way transmitting/receiving operations is one cycle, and the content of S, which indicates how many times this cycle is, is set to 1. The processing to do so is executed (step 101).

Next, the content of n is set to 1 (step 102), and a transmitting/receiving operation signal is output to the nth set (that is, the first set) of transmitting/receiving devices. In this case, the CPU 17 controls the timing trigger circuit generator 13 as required, and the AND circuit 3]
A transmitting/receiving operation signal of logic "1" level is output only from the terminal.

Then, the rising edge of this transmission/reception operation signal is triggered, and the time (t-
Radio waves (transmission pulses) are emitted underground from transmitter]-a and are reflected by the underground cavity CV, etc.
The reflected wave (reflected echo) is received by the receiver 1b (see FIG. 4, step 103). During this time, it is sequentially determined whether a reception completion signal has been output from the 0th set (n=1) of receivers (step 104). If S=1 and n=1, the process of step 105 is not performed.

Eventually, when the reception of the reflected wave is completed in the receiver of the 0th set (n = 1), a reception completion signal is input from the same receiver, so the judgment result in step 104 becomes YES.
Next, the 0th set (n=1) of transmitters/receivers, that is, the transmitter/receiver that has been
Transmit/receive data to the transmitter/receiver pair that was receiving
The reception operation signal is lowered to stop the transmission and reception operations by this group (first group) (see arrow B in FIG. 4, step 106).

1 Then, the current position X5n (
X11), that is, 5 (S-1-) times "The time (t
The position of the mobile cart] 1 at = t 11) is input (see FIG. 4, step 104).

Next, n is incremented (step 108), and it is determined whether the increment value n is 9 or more (step 109).

If the judgment result in step 109 is NO1, that is, one cycle of vermilion has not been completed, the procedure repeats step 1 above.
It will be moved to 03.

In step 103, as described above, a process of outputting a transmitting/receiving operation signal to the transmitter/receiver of the 0th set (n=2) is executed, and from the time when this signal rises, the 0th set (n=2)
) transmitting and receiving operations are performed in the same way as described above (see arrow E in FIG. 4).

While the above transmission/reception operations are being performed, the 0th group (n=2
) is sequentially determined based on whether a reception completion signal is input from the receiver. The result of this judgment is N.

, that is, during the time Tn (T; see Figure 4) during which transmission and reception are performed by the 0th set (n = 2) transmitter and receiver,
The echo signal received by the receiver (first set of receivers) in the previous process (steps 101-111) is input to the CPU 17, and the input echo signal and the echo signal obtained in the previous step 107 are input to the CPU 17. Position X5 of mobile cart 11-
An image signal vD'5n (vD'1□) corresponding to one scan of a two-dimensional cross-sectional image of the underground is created based on Output to TV monitor 18. The TV monitor 8 receives the above image signal VD'
Based on sn (V D' 11), the moving trolley 11
At the position x sn (x 1t), the 0th set (n=
The echo image received by the receiver of
=1) Transmitter/receiver installation position Yn (Y; see Figure 1)
The echo image obtained at the X coordinate position X sn (X u) under the movement line Lt (see Figure 1) corresponding to
a as VDsn (VDl, 1.) (6th
(See figure (b)). Note that the details of this image processing will be described later (step 105).

Eventually, when the reception of the reflected wave is completed in the receiver of the 0th group (n = 2), a reception completion signal is input from the receiver, and the judgment result in step 1.04 becomes YES, and the transmission/reception operation has been continued until now. The transmitting/receiving operation signal is lowered for the transmitter/receiver pair (second pair) where the
Transmission/reception operations by this group (second group) are stopped (see arrow F in FIG. 4, step 106).

Then, in the same way as above, the 0th cycle of the Sth (]th cycle
The time (t = t
Position X5n (X12) of mobile cart 11 in 12)
will be input (see Figure 4, Step 1-0)
7).

Next, the processes of steps 108 and 109 are executed, n is incremented, and the incremented n
It is determined whether or not is 9 or more.

If one cycle has not yet been completed, the procedure moves to step 103 again, after which a transmitting/receiving operation signal is output to a new set (n=3) of transmitting/receiving devices (the fourth
(See arrow G in the figure) The judgment process of step 104 is performed.

Similarly, during the judgment process in step 104 (period T;
The echo signal of the receiver of the previous edition (n=2) is input to the transmitter/receiver arrangement position Yn (Y; see Fig. 1) of the previous set (n=2). The echo image V D sn (V D L 2 ) obtained at the X coordinate position X5n (X
) is displayed on the screen 18a of the TV monitor 8 (step 105).

Thereafter steps 106-109 and steps 102-1
The process of 05 is repeatedly executed.

Eventually, when the judgment result in step 109 becomes YES,
In other words, n is reset to 1 at the point in time when - transmission/reception operations by the transmitter/receivers from the 1st set to the 8th set have been completed (1 = 1; see Figure 4; position X; see Figure 1). [Step 1]-〇) The number of cycles S is incremented (Step 111).

Thereafter, in a new cycle, the same process will be repeated for the first to eighth sets of transmitters/receivers.

When the mobile cart 11 eventually reaches the terminal end X of the exploration area AR of the cavity CV (see FIG. 1), all the processes in the flowchart are completed.

As shown in FIG. 1, at the time when the mobile trolley [1] reaches the X coordinate position X1 of the exploration area AR, each position X11 . The echo images obtained by the first to eighth receivers at X12° . . . , X18 are all displayed on the screen 18a of the TV monitor 8.

From then on, the mobile cart 11 moves to the X coordinate position X of the exploration area AR.
,X,...,Xs..., each position X28 up to position X28
．． 2 21, 22
Each position up to position X , X , ..., X38
, place 3 31, 3
Each position from Xs to Xs is
It will be displayed on the screen 18a of the monitor 8. Then, when the mobile cart 11 reaches the terminal end XIΣ, all the echo images obtained at each point on the XY plane of the exploration area AR are displayed.

Regarding the transmitter/receivers from the first set to the eighth set, the transmitter/receiver of the first set creates a two-dimensional cross-sectional image under the movement line L1 corresponding to the installation position Y1, that is, in FIG. A two-dimensional cross-sectional image VD-1 indicated by a wavy line is obtained, and this cross-sectional image Vl)-1 is displayed on the screen 18a of the T2 monitor 18 (see FIG. 6(b)).

Furthermore, the transmitter/receiver of the second set, ..., and the eighth set move the position corresponding to the installation position Y, ..., Y8.
2..., two-dimensional cross-sectional image VD-2° below L8...
, VD-8 are obtained, and these cross-sectional images VD-2°...
, VD-8 is displayed on the screen 1.8a of the TV monitor 8. Furthermore, the first set, second set, .
, ..., W8 (see Figure 1), these search widths W, W2 . ..., Exploration areas AR-1, AR-2, ... Exploration under AR8 is the first
This means that the transmitter/receiver set, second set, . . . , and eighth set transmit/receive, respectively.

Here, we will explain the principle by which the underground cavity CV is observed as a hyperbolic echo image on the display screen], 8 a.
An echo image under the exploration area AR of the embodiment is displayed on the display screen 18a.
Explain what is displayed above.

That is, as shown in FIG. 6(a), the above-mentioned moving trolley]
Let the coordinate axis of the distance when 1 moves on the ground surface be X1, and the coordinate axis showing the distance in the depth direction toward the ground be Z. Assuming that the apex TP of the cavity C■ is at the coordinates (X, ZO), if the transmitting and receiving antennas 1A and 1°B are located at a point J directly above the point TP, the apex of the cavity CV is at the point J. , TP can be observed as an echo image at a depth of 20 corresponding to the distance below TP.

On the other hand, since the transmitted radio waves have a spread in the propagation direction, the transmitting/receiving antenna IA, 1.8 is at the point J directly above the point TP.
Cavity CV also occurs when moving to point H shifted to the right from
The echo image of the surface of can be #Jl i'jllJ. In this case, the transmitted radio wave is transmitted to the point TP on the surface of the cavity CV.
', and the echo image is reflected at the distance H between points HTP'.
It can be observed as an echo image at a point K at a depth corresponding to -TP'.

Therefore, as shown by the broken line in the figure, the locus of the point K (x, z) when the mobile cart is moved, that is, the cavity CV
The echo image of + (Z) 211/2 = H-TP'...(1
) becomes a hyperbola represented by .

On the other hand, there is the following relationship between the round trip propagation time τ until the radio wave emitted from the transmitting antenna IA is received by the receiving antenna IB, the radio wave propagation velocity vg, and the depth Z to the surface of the cavity CV.

Therefore, by equations (1) and (2), ((x
x o ) ■g″rO) 2) 1/2 + (vg ・τ = ...(3
) holds true. However, τ. is the propagation time at point J, τ is the propagation time at point H, and Xo, τo,
vg is an unknown quantity.

On the other hand, in the echo image displayed on the TV monitor 18, as shown in FIG. 6(b), the horizontal axis is the distance axis X, and the vertical axis is the time axis. Therefore, the echo image of the surface of the cavity CV is displayed by converting the distance 1111Z in the depth direction to the time axis τ.

Therefore, based on the information obtained from the echo image displayed on the TV monitor 8, the echo image is

It is defined by a joint-like relationship in the τ coordinate system.

f(x−x)+(α·τ)2, 1. /20〇−α・τ ...(4) Then, the (3rd
) and the fourth equation, the following relationship is established.

v g=2α...
(5) Once each of the unknowns in equation (3) is determined in this way, vg. By substituting the above equation (2), the coordinates of the apex position of the echo image on the surface of the cavity Cv, that is, the depth of 2°, can be easily determined. Once the depth zo is determined in this manner, the distance J-TP-2o from the ground surface (road RD surface) to the apex of the cavity CV can be determined.

In the end, the echo image EP on screen 1.8a is
If it can be obtained in the form of the equation, the position information of the echo image EP, that is, the cavity CV
This means that the vertex position coordinates (x, z) can be found.

Therefore, the equation of the hyperbola is obtained from the screen 18a, which is based on the applicant's patent application (Japanese Patent Application No. 61
．． -273381), that is, a method called the so-called curve fitting method in which a pseudo echo image is formed and superimposed on the echo image on the screen, or Japanese Patent Application No. 11471/1989 filed by the same applicant. This can be done using the technique described, that is, a method in which image information is subjected to arithmetic processing and a hyperbolic equation is determined by the least squares method based on this arithmetic processing.

In either case, superimposition and arithmetic processing are performed by the input operation of the above-mentioned keyboard input device] and 9. However, since this differs from the gist of the present invention, a detailed explanation will be avoided here.

In any case, when the equation of the hyperbola is determined by the above method, the apex position of the cavity Cv is
Xz coordinate position or Xo such as Zo 2 plane, that is, 2 in two-dimensional cross section VD-1 in
Obtained as dimensional position data (x, z).

Note that, as is clear from the above explanation, the mobile trolley 11
is located at point X1■, the image corresponding to VD1□ of two-dimensional cross-sectional image VI)-1 is also located at point X2
1, the image corresponding to VD21 of the two-dimensional cross-sectional image VD-1 is the two-dimensional cross-sectional image VD-1, and when the mobile cart 11 is located at the point Xsl, the two-dimensional cross-sectional image VD-
It can be seen that an image corresponding to VDsl of 1 can be obtained (
(See Figure 6(b)).

An image V similar to the two-dimensional cross-sectional image VD-1 in FIG.
D-2, .

Note that the two-dimensional cross-sectional image VD-1. VD-2,-...VD
-8 may be displayed on eight separate screens, and the two-dimensional cross-sectional image VD-1. VD2...VI)-
8 may be switched and displayed.

Of course, it is also possible to divide the - screen into eight parts and simultaneously display the images VD-1, VD-2, . . . , Vl)-8 on each of the divided parts.

In this way, eight images VD-1, VD-2,...Vl
)-8 is displayed, each image has a Y coordinate position of Y,
Since it is a two-dimensional cross-sectional image of the x-z plane with Y, ..., Y8, the position of the cavity CV under the exploration area AR is
Dimensional detection becomes possible.

Conventionally, exploration was carried out using only one set of transmitter/receiver, for example, transmitter/receiver unit 1, so mobile trolley ]-1 moves from ST to XE along the X axis of exploration area AR. Even if this were done, it would be impossible to obtain a two-dimensional cross-sectional image VD-IL above and below the movement line of the transmitter/receiver unit 1. Furthermore, the search area A defined by the search width W1 of the transmitter/receiver unit 1
If there is no cavity CV under R1, it is possible to move the Y coordinate position of the transmitting/receiving unit 1 from YI to a different position Y again, move it on the movement line L2, and search for the cavity CV. According to the example,
The exploration width w + w is obtained by moving the mobile cart 1] - times.
+, . . . defined in +w8] 2 Since it is possible to explore the vast exploration area AR, it is possible to reliably detect a cavity CV that exists somewhere under this vast exploration area AR. .

Further, according to the embodiment, while the - transmitting/receiving unit is transmitting/receiving, other transmitting/receiving units do not perform transmitting/receiving, so no radio wave interference occurs. The effect is that an accurate two-dimensional cross-sectional image can be obtained.

In the embodiment, two-dimensional cross-sectional images VD-1. parallel to the X-Z plane are used. ．． VD-2,-, VI)-8, but of course Y is displayed using the same method as in the embodiment.
It is also possible to display two-dimensional cross-sectional images VD'-1 (indicated by dashed lines in FIG. 1) parallel to the -Z plane.

In addition, in the embodiment, the movable trolley 11. Although the explanation has been made on the assumption that the probe is moving at a constant velocity V, it goes without saying that the same search can be performed even if the opening speed at which the search is being performed changes. In addition,
When the movable cart 11 moves at a constant speed ■, if this speed V is known in advance, the transmitting/receiving unit 6 can transmit/receive without providing the position detector 6 as shown in FIG. By measuring the time T , T , T , .
, X , X , . . . can be measured. The mobile cart] 1 may be driven by a motor as in the embodiment, or may be moved manually.

In addition, in the example, a two-dimensional cross-sectional image of the underground is displayed on the TV monitor 1.
Although the image is displayed on the screen 1.8a of 8, it is also possible to transfer the equivalent image to a medium such as paper using a hard copy device or the like and leave a record.

In addition, in the example, the object to be investigated is assumed to be a hollow CV under the road RD surface, but of course it is not limited to a hollow CV, and if it is an underground object to be investigated, explosives, water pipes, etc. Implementations to explore and detect are also possible.

〔Effect of the invention〕

As explained above, according to the present invention, a wide exploration area can be surveyed at one time, so the working efficiency of underground exploration is greatly improved. Moreover, since no radio wave interference occurs, exploration can be performed accurately.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the appearance of an example of an underground exploration device according to the present invention and an exploration area of an embodiment, and FIG. 2 is a block diagram showing the configuration of the underground exploration device shown in FIG. 3 is a circuit diagram illustrating the circuit configuration of the timing trigger generator shown in FIG. 2, FIG. 4 is a time chart showing the operation of the timing trigger generator shown in FIG.
Flowcharts illustrating processing steps not shown (not shown) performed by the CPU, FIGS. 6(a) and 6(b) show that the reflected echo image of the cavity shown in FIG. 1 is displayed on the display screen of the TV monitor shown in FIG. 2. FIG. ], 2, 3, 4, 5, 6, 7.8... Transmitting/receiving unit, ]-a, 2 a + 3 a + 4
a + 5 a, 6 a. 7a, 3a--transmitter, 1. A, 2A, 3A, 4A. 5A, 6A, 7A, 8A... transmitting antenna, 1b. 2b, 3b, 4b, 5b, 6b, 7b, 8b...Receiver, ], B, 2B, 3B, 4B, 5B, 6B, 7B, 8
B...Receiving antenna,]0...Underground exploration device, 11
...Moving trolley,]2...Part of CPU unit,]3
... timing trigger generator, 16 ... position detector, core ... CPU, 1.8 ... TV monitor, ],
8 a...Display screen, AR...exploration area, CV...
Hollow, Ll. L2, Lg...Movement line, RD...Road, VI)-1VD-2, VD-8...Two-dimensional cross-sectional image.

Claims (2)

[Claims] (1) The radio waves emitted underground from the transmitter mounted on the movable trolley tower are reflected by the target to be explored, and the receiver mounted on the movable trolley tower receives the reflected waves, and the propagation time of the reflected waves is used to determine the target In a radar type underground exploration device that detects a position, a plurality of sets of the transmitter/receiver are arranged in parallel along the width direction of the mobile cart, and the plurality of sets of transmitters/receivers are arranged in a preset order. a transmitter/receiver operating means for sequentially operating the transmitter/receiver according to the output of each receiver of the plurality of sets of transmitters/receivers;
An underground exploration device characterized by comprising means for detecting the position of the object to be investigated under the movement plane of the plurality of sets of transmitters and receivers. (2) The radio waves emitted underground from the transmitter mounted on the movable trolley tower are reflected by the target to be detected, and the reflected waves from the target to be detected are received by the receiver mounted on the mobile trolley tower, and the propagation time of the reflected waves is used to detect the target In a radar type underground exploration device for detecting a position, a plurality of sets of the transmitter/receiver are arranged in parallel along the width direction of the mobile cart, and each of the plurality of sets of transmitters/receivers has a transmitter/receiver. - A transmitting/receiving operation means that emits the radio wave and receives the reflected wave only while the reception operation signal is input; and a reception completion signal output that outputs a reception completion signal when reception of the reflected wave is completed. means, when each transmitter/receiver of the plurality of sets of transmitters/receivers outputs the reception completion signal, transmitting the transmission/reception operation signal to the transmitter/receiver that outputs the reception completion signal. a transmitting/receiving operation signal output means for stopping the output and sequentially outputting the transmitting/receiving operation signal to the next set of transmitting/receiving devices according to a preset order; The propagation time of the reflected wave obtained each time each transmitter/receiver of the plurality of sets of transmitters/receivers outputs the reception completion signal, and the movement of the mobile cart obtained each time the reception completion signal is output. an image forming means for forming an underground two-dimensional cross-sectional image under each movement line of the plurality of sets of transmitting/receiving devices based on the distance and the order in which the transmitting/receiving operation signals are output; and the image forming means 2 underground formed by
display means for displaying a dimensional cross-sectional image for each of the plurality of transmitter/receiver pairs, with the depth direction from the ground surface and the moving direction of the movable trolley as vertical and horizontal axes, respectively, and displayed on the display means. An underground exploration device characterized in that the position of the object to be explored is detected based on the information obtained.