JPH0712954A - System and device for searching object buried underground - Google Patents

Abstract

PURPOSE:To improve the searching accuracy of a device which searches object buried underground in a noncontact state by radiating radio waves against the objects by removing unnecessary reflected wave components from the ground surface. CONSTITUTION:An object buried underground is searched by radiating non-modulated radio waves toward the ground through an antenna 3 from a high-frequency transmitter 1 while a ground surface scanning machine 8 is moved in parallel with the ground surface and receiving reflected waves from the ground surface by means of a high-frequency receiver 2 through the antenna 3, and then, analyzing the receiving level of the reflected waves by means of a signal processing section 10. At the same time, the height signal of the machine 8 from the ground surface is obtained by radiating an ultrasonic pulse signal from an ultrasonic radiating device 6 and calculating the time until the reflected wave of the signal from the ground surface is sensed by an ultrasonic wave sensing device 7 at a height measuring section 9. At the time of analyzing obtained data, the variation of the receiving level caused by unnecessary reflected waves generated by the ruggedness of the ground surface is removed by referring to previously prepared calibration data indicting the correlation between receiving level signals and height signals and only the variation of the receiving level from the object buried undergroud is fetched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground buried object detection system for detecting an object buried in a shallow ground in a non-contact manner by using an unmodulated radio wave, and an underground buried object detection apparatus using this system. Regarding

[0002]

2. Description of the Related Art Unmodulated radio waves are radiated toward the ground from a scanning means for scanning the ground in the horizontal direction, and a change in reflection coefficient as an integrated value near the ground surface is reflected by the reflected wave on the ground. By detecting as a change in the reception level of
An underground buried object detection device is known which detects an object buried in the ground.

[0003]

When the target object buried in the ground has a small reflection coefficient for radio waves, the level of the reflected wave from the target object and the unevenness of the ground surface or the antenna provided on the scanning means. And the level of the unnecessary reflected wave due to the altitude change from the ground surface approaches, and it becomes difficult to identify the reflected wave from the target.

Therefore, conventionally, for example, Japanese Patent Publication No. 2-13
As disclosed in U.S. Pat. No. 756, the reflected waves from the ground surface are received by a plurality of antennas arranged apart from each other, and a plurality of reflected wave reception levels obtained by this are subtracted from the ground surface to obtain the reflected waves. The reflected waves from the underground buried object are detected by canceling the unnecessary reflected waves of the above.In this method, the incident of the reflected waves from the ground surface to the antenna is independent of the position of the antenna. It is assumed that they occur at a uniform level, and depending on the condition of the ground surface, the above-mentioned unnecessary reflected waves are not sufficiently canceled, and the subtraction process also causes the reception level of the reflected waves from the underground buried object to be relatively high. Since the S / N ratio is extremely low especially for a target object having a small reflection coefficient, the detection of the buried object in such a situation requires a very complicated process that requires many conditions. To do.

Therefore, according to the present invention, a signal level of a true reflected wave (a reflected wave from a buried object which is a target object) is rationally identified from the detected signal level including the unnecessary reflected wave component by a simple and reliable method. It is a first object to provide an underground buried object detection device that can be performed.

Further, since the conventional underground buried object detecting apparatus generally detects only the existence of the underground buried object, it is immediately judged whether or not the detected underground buried object is the target object. It is not possible.

Therefore, the present invention provides an underground buried object detecting apparatus capable of determining the shape of an underground buried object from detection data and discriminating whether or not the detected underground buried object is a target object. Is the second subject.

[0008]

In order to solve the above problems, the present invention measures the reception level of a reflected wave on the ground of an unmodulated radio wave radiated toward the ground and radiates the unmodulated radio wave. , And the altitude from the ground surface of the ground scanning means provided with an antenna that is sensitive to the reflected waves, is measured by a measurement medium having physical properties different from radio waves, such as ultrasonic waves. When detecting a medium buried object, measure the relationship between the reception level of the reflected wave and the altitude of the ground scanning means in advance in the area where there is no buried object in the detection area, and hold the correlation data between them as calibration data. The reception level data of the reflected wave obtained by the ground scanning by the ground scanning means in the detection area and the altitude data of the ground scanning means are processed based on the calibration data to obtain the reception. The bell data is used to detect as much as possible the change in the reception level due to unnecessary reflected waves on the ground surface, thereby detecting the presence of underground buried objects. By providing a plurality of side by side in a direction orthogonal to the direction, for a plurality of points on the ground, while measuring the reception level data and altitude data, to measure the scanning movement distance of the ground scanning means,
By displaying the reception level change data of each of the plurality of points obtained by the processing based on the calibration data in parallel with the distance data obtained by the scanning movement distance measurement as an axis, the shape of the underground buried object can be displayed. It was done like this.

[0009]

In the present invention, the received level change due to the reflected wave from other than the underground buried object is removed based on the calibration data indicating the relationship between the altitude of the ground scanning means and the received level of the reflected wave measured in advance. Therefore, the amount of change in the reception level due to the reflected wave from the underground buried object fluctuates significantly (decreases) due to the correction
In addition, since the calibration data used for the correction processing includes the correlation with the altitude of the ground scanning means, even if the altitude of the ground scanning means changes from the ground surface during scanning, unnecessary reflection due to the fluctuation is caused. The wave component does not remain in the detection data, the reception level change due to the unnecessary reflected wave can be effectively removed, and the underground buried object can be reliably detected.

[0010]

1 is a block diagram of a first embodiment, FIG. 2 is a block diagram of a second embodiment, FIG. 3 is a first embodiment and a first embodiment. 4A is a block diagram of an altitude measuring unit in the second embodiment, FIG. 4A is a perspective view showing a main structure of a ground scanner, FIG. 4B is a sectional view taken along line AA in FIG. 4A, and FIG. 6A to 6C are diagrams for explaining the calculation processing of the calibration data, FIG. 6 is a diagram for explaining the buried object detecting operation of the first embodiment, and FIG. 7 is a diagram for explaining the buried object detecting operation of the second embodiment. Is.

First, the device configuration of the first embodiment will be described.

In the first embodiment, as shown in FIG. 1, a high frequency transmitter 1 (first transmitter) for generating and outputting an unmodulated high frequency signal and reflection from the ground (ground surface and underground). From a high frequency receiver 2 (first receiver) that receives a wave (reflected wave of unmodulated radio wave) and outputs a signal (reception level signal) proportional to the reception level of the reflected wave, and from the high frequency transmitter 1. An antenna 3 which is supplied with a high-frequency signal to radiate an unmodulated radio wave, and a reflected wave of the unmodulated radio wave on the ground is incident to generate a high-frequency signal, the output of the high-frequency transmitter 1, and the high-frequency receiver 2 A circulator 4 which is interposed between the antenna 3 and the high-frequency transmitter 1 and the high-frequency receiver 2, and an AC pulse signal (hereinafter referred to as a pulse signal) having a frequency in the ultrasonic signal region. Generate and output pulse signal transmitter 5 ( 2 transmitter), an ultrasonic wave radiator 6 which is supplied with a pulse signal from the pulse signal transmitter 5 and emits an ultrasonic pulse signal, and a surface of the ultrasonic pulse signal from the ultrasonic wave radiator 6 Ultrasonic sensing device 7 that senses the reflected wave of the ultrasonic wave to generate an ultrasonic pulse signal, a ground scanner 8 equipped with the antenna 3, the ultrasonic radiator 6 and the ultrasonic sensing device 7; The ultrasonic pulse signal from the ultrasonic wave receiver 7 is received, and the time difference from the time when the pulse signal is transmitted from the pulse signal transmitter 5 to the time when the ultrasonic pulse signal is received is calculated to calculate the time of the ground scanner 8. An altitude calculator 9 that outputs, for example, a voltage signal (altitude signal) proportional to the altitude from the ground surface
A signal processing unit 10 for processing the reception level signal output from the high frequency receiver 2 and the altitude signal output from the altitude measuring unit 9 to generate detection data; and data processing in the signal processing unit 10. A memory 11 for storing various data (reception level signal, altitude signal, calibration data described later, etc.) necessary for the operation, and a clock oscillator 12 for generating a clock signal which serves as a time reference for arithmetic processing of the signal processing unit 10.
And a data display unit 13 for displaying detection data output by the signal processing unit 10, and an alarm sound is generated when the detection data displayed on the data display unit 13 includes data indicating the presence of an underground buried object. (Audible alarm display) or / and / or alarm lamp is turned on (or flashes) (visual alarm display) Alarm display unit 14 and mode for setting operation mode of underground buried object detection device (device shown in FIG. 1) It is configured by the setting unit 15.

As shown in FIG. 3, the altitude measuring section 9 includes an ultrasonic receiver 901 (second receiver) which receives the ultrasonic pulse signal from the ultrasonic receiver 7 and outputs the pulse signal. ,
By setting each part constituting the altitude calculation part, that is, the pulse signal from the pulse signal transmitter 5, and resetting by the pulse signal from the ultrasonic receiver 901,
An S / R flip-flop 902 that outputs a rectangular signal having a length proportional to the altitude from the ground surface of the ground scanner 8;
A clock oscillator 903 which outputs a time reference signal (clock pulse) for measuring the length of the rectangular signal from the R flip-flop 902, and the S / R flip-flop 90.
The AND gate 904 that outputs the number of clock pulses corresponding to the length of the rectangular signal and the number of clock pulses output by the AND gate 904 are counted by the logical product of the output of 2 and the output of the clock oscillator 903. It is composed of a counter 905 and a D / A converter 906 that converts the count output (digital value) by the counter 905 into a voltage (analog value) and outputs the altitude signal of the ground scanner 8.

In the structure of the first embodiment, the antenna 3 may be composed of a transmitting antenna directly connected to the high frequency transmitter 1 and a receiving antenna directly connected to the high frequency receiver 2. In some cases, the circulator 4 is unnecessary. Further, by interposing a switching device between the pulse signal transmitter 5 and the altitude measuring unit 9 (ultrasonic wave receiver 901), the ultrasonic wave radiator 6 and the ultrasonic wave receiver 7 are combined into one ultrasonic vibration. It can also be used as a container.

The structure of the ground scanner 8 is shown in FIGS. Antenna 3 of unmodulated radio wave that constitutes the ground scanner 8
The ultrasonic radiator 6 and the ultrasonic receiver 7 are of a horn type in order to limit the irradiation range of radio waves and ultrasonic waves when scanning the ground.

That is, for example, a rectangular box-shaped electromagnetic horn 8 formed by opening the lower surface with a metal such as aluminum.
01 and a power resonance rod 802 (resonator) horizontally projecting from the side surface of the electromagnetic horn 801 to a substantially central portion of the internal space of the electromagnetic horn 801, the antenna 3 is configured,
The vibrating surfaces 805A and 806A are passed through holes 803 and 804, which are provided on the upper surface of the electromagnetic horn 801, symmetrically with respect to the power resonance rod 802.
1. Ultrasonic transducers 805, 806 arranged toward the inside of
And a base member 807A, 808 formed in a member having a very low dielectric constant (close to the dielectric constant of air), such as mylar film, in the internal space of the electromagnetic horn 801.
A is a vibrating surface 805 of the ultrasonic transducers 805 and 806.
The ultrasonic radiator 6 and the ultrasonic wave are fixed by the ultrasonic horns 807 and 808 which are fixed to the A and 806A sides and are attached with the openings 807B and 808B on the lower side (the opening direction is the same direction as the electromagnetic horn 801). The receiver 7 is configured.

The power resonance rod 802 is directly fixed to a contact plug 809 provided on the side surface of the electromagnetic horn 801, and the ultrasonic transducers 805 and 806 are covered with rubber cushion materials 810 and 811. 812, 813
Is fixed to the upper surface of the electromagnetic horn 801 by means of the terminals 805B and 806B.
1. A plug 8 provided at an appropriate location (top surface in the embodiment)
14, the power resonance rod 802 and the circulator 4 are connected via a plug 809, and the ultrasonic transducers 805, 806, the pulse signal transmitter 5, and the altitude measuring unit 9. The connection between them is made via a plug 814.

Further, the ultrasonic horn 80 is located in front of the vibrating surfaces 805A and 806A of the ultrasonic transducers 805 and 806.
7, 808 are attached to holes 803, 804 provided on the upper surface of the electromagnetic horn 801, and base portions 807A, 808 thereof.
A is bonded and fixed, and this bonding and fixing is performed by a gap between the base portions 807A and 808A of the ultrasonic horns 807 and 808 and the holes 803 and 804 of the electromagnetic horn 801 (the inner diameters of the holes 803 and 804 are the base portions). 807A and 808A are set to have a diameter slightly larger than the outer diameters of 807A and 808A).
By filling 5,816.

In the ground scanner 8 constructed as described above, there are two ultrasonic horns 807, 808 in the internal space of the electromagnetic horn 801. As described above, the ultrasonic horns 807, 808 are dielectric. Since the member having a very low rate is used, the emission of unmodulated radio waves by the power resonance rod 802 is not hindered, and the electromagnetic horn 8 is used.
For fixing the ultrasonic transducers 805 and 806 and the ultrasonic horns 807 and 808 to 01, the cushion material 81 is provided.
Since 0, 811, and the elastic fillers 815, 816 are interposed, the ultrasonic vibration is not transmitted to the electromagnetic horn 801, and accordingly, the ultrasonic signal does not leak into the unmodulated radio wave ( Since the unmodulated radio wave is not modulated by the ultrasonic signal), the emission of the unmodulated radio wave is not disturbed.

Further, due to the presence of the ultrasonic horns 807 and 808, the ultrasonic pulse signal from the ultrasonic transducer (eg, 805) on the transmitting side is reflected by the power resonance rod 802 and the ultrasonic transducer (eg, on the receiving side) (eg, 806), and shock-absorbing materials (cushioning materials 810, 8) for attaching the ultrasonic transducers 805, 806 to the electromagnetic horn 801.
11, the presence of the elastic fillers 815, 816) prevents the vibration of the ultrasonic transducer 805 from being directly transmitted to the ultrasonic transducer 806 via the electromagnetic horn 801, so that the ultrasonic pulse signal output side There is no leakage from the output side to the input side (transmitting directly from the output side to the input side without passing through the reflection on the ground surface).

Two ultrasonic transducers 805 and 806 are also provided.
Is provided at a position symmetrical with respect to the power resonance rod 802 (power feeding point), so that the altitude of the ground scanner 8 can be measured directly below the emission direction of the unmodulated radio wave.

Next, the operation of the first embodiment will be described.

The high frequency transmitter 1 always outputs an unmodulated high frequency signal, and this high frequency signal is supplied to the antenna 3 (power resonance rod 802) of the ground scanner 8 through the circulator 4, whereby the antenna 3 is supplied. Unmodulated radio waves are radiated from the ground to the ground.

When the unmodulated radio wave radiated from the antenna 3 reaches the ground, it is reflected on the ground surface and in the ground, and the reflected wave generated thereby enters the antenna 3, whereby the antenna 3
A high frequency signal is induced and generated, and the high frequency signal is received by the high frequency receiver 2 via the circulator 4, and the high frequency receiver 2 outputs a reception level signal proportional to the reception level of the received high frequency signal.

Further, the pulse signal transmitter 5 outputs a pulse signal at a constant cycle, and this pulse signal is supplied to the ultrasonic wave radiator 6 (ultrasonic wave transducer 805) of the ground scanner 8 and thereby the ultrasonic wave is transmitted. An ultrasonic pulse signal is emitted from the acoustic wave radiator 6 toward the ground.

When the ultrasonic pulse signal radiated from the ultrasonic radiator 6 reaches the ground, it is reflected on the ground surface (the ultrasonic pulse signal does not reach the ground and is not reflected.). Is an ultrasonic transducer 7 (ultrasonic transducer 80
6), so that an ultrasonic pulse signal is induced and generated in the ultrasonic receiver 7 and the ultrasonic pulse signal is input to the altitude measuring unit 9.

The altitude measuring unit 9 measures the altitude of the ground scanner 7 and outputs an altitude signal as follows. That is, the pulse signal transmitter 5 sends the pulse signal to the altitude measuring unit 9 (or triggers for sending the pulse signal to the ultrasonic wave emitter 6 at the same timing as sending the pulse signal to the ultrasonic wave emitter 6). Signal), and this pulse signal is S
/ R flip-flop 902 is input to the set terminal S and the level of the output terminal Q thereof is inverted to positive, whereby the AND gate 904 is opened and the clock oscillator 903 is opened.
Is supplied to the counter 905 through the AND gate 904, and the counter 905 starts counting the clock pulses.

Next, when the ultrasonic pulse signal from the ultrasonic sensor 7 is input to the altitude measuring unit 9, the ultrasonic pulse signal is received by the ultrasonic receiver 901, and the ultrasonic receiver 901 receives the ultrasonic pulse signal. 901 outputs a pulse signal to the reset terminal R of the S / R flip-flop 902, whereby S
The level of the output terminal Q of the / R flip-flop 902 is inverted again to a negative level, and the AND gate 904
Is closed and the output of the clock pulse from the clock oscillator 903 to the counter 905 is stopped.
Counting operation stops.

At this time, the pulse signal output from the ultrasonic receiver 901 is slightly delayed by a unit (not shown), and then the counter 905 and the D / A converter 906.
Then, the D / A converter 906 outputs a voltage signal corresponding to the count value of the counter 905 at that time, and the counter 905 is reset to prepare for the next counting operation.

From the time the S / R flip-flop 902 is set to the time it is reset (until the level of the output terminal Q inverts to plus and then to minus again)
Corresponds to the time required for the ultrasonic pulse signal to make a round trip between the ground scanner 8 and the ground surface, and this time is proportional to the height of the ground scanner 8 from the ground surface. Therefore, the voltage signal from the D / A converter 906 which has converted the count value of the counter 905 representing the above time into a voltage value becomes a signal proportional to the height of the above ground scanner 8 from the ground surface. In this way, the altitude measuring unit 9 outputs the altitude signal of the ground scanner 8.

As described above, the reception level signal of the reflected wave of the unmodulated radio wave output from the high frequency receiver 2 and the altitude signal of the ground scanner 8 output from the altitude measuring unit 9 are the signal processing unit 10 It is stored in the memory 11 by the processing of.
In this storage processing, both the reception level signal and the altitude signal input to the signal processing unit 10 are analog values, but the reception level signal and the altitude signal are the analog and digital signals that the signal processing unit 10 itself has. It is converted into digital data based on the same standard by the conversion function and stored in the memory 11.

The signal processing unit 10 performs a process of calculating buried object detection data and a process of calculating calibration data for the process.

First, the calculation processing of the calibration data will be described.

In order to obtain the calibration data, the following calibration operation is performed prior to the detection operation. That is, the calibration mode is set by the mode setting unit 15, and the ground scanner 8 is moved vertically up and down by several centimeters with respect to the measurement setting altitude on a flat ground without buried objects in the underground buried object detection area. To move.

The signal processing unit 10 stores the reception level signal obtained from the high frequency receiver 2 and the altitude signal obtained from the altitude measuring unit 9 in the above operation in each predetermined area during the calibration operation. Then, calibration data is created from the reception level signal and the altitude signal stored in the memory 11.

FIG. 5 shows an example of the data for explaining the calculation processing of the calibration data. FIG. 5A shows the time when the ground scanner 8 is moved and the data obtained during the movement. The relationship between the altitude signal (voltage value)
Shows the relationship between the time when the ground scanner 8 is moved and the reception level signal (voltage value) of the unmodulated radio wave reflected wave obtained during the movement.

The above two data are stored in the memory 11 by the calibration operation of the ground scanner 8 as described above, and the signal processing unit 10 is instructed by the instruction to create the calibration data.
The altitude signal h from the memory 11 at the same travel time (t)
(T) and the reception level signal v (t) are sequentially read out, and are transferred to Cartesian coordinates with the horizontal axis of the altitude signal h (t) and the vertical axis of the reception level signal v (t). For example,
At the travel time t1, the altitude signal is h from FIG. 5 (A).
1, the reception level signal is v1 from FIG. 5 (B), and when this is moved to the coordinates in FIG. 5 (C), it becomes the point P. When this process is continuously performed over the entire recording time t0 to tn of the calibration data, the calibration data shown in FIG. 5C is obtained, and the calibration data is stored in a predetermined area of the memory 11.

The calibration data created as described above includes the altitude from the ground surface of the ground scanner 8 and the intensity of the reception level of the reflected wave from the ground (ground surface and underground) of the unmodulated radio wave. In the relationship, the data reflects the reflection coefficient due to the geology peculiar to the detection area.

Next, the operation of detecting an underground buried object and the data processing at that time will be described with reference to FIG.

The condition of the ground surface P and the buried portion of the buried object Q are as shown in FIGS.

The operation of detecting an underground buried object is performed by moving the ground scanner 8 in the horizontal direction with respect to the ground surface P. At this time, the mode setting unit 15 sets the operation mode to the detection mode.

While the ground scanner 8 is moving, the above operation causes the high frequency receiver 2 to output a reception level signal as shown in FIG. 6A at the point A, and the altitude measuring unit 9 at the point B as shown in FIG. The altitude signal as shown in is output.

Since the reception level signal includes all the reflected wave components of the unmodulated radio wave on the ground surface and in the ground, as shown in FIG. 6A, both the unevenness of the ground surface P and the buried object Q are present. It becomes a waveform that expresses the existence of the indiscriminately. On the other hand, since the altitude signal includes only the reflection component of the ultrasonic signal on the ground surface P (the ultrasonic signal does not reach the ground), as shown in FIGS. The waveform shows only that.

The signal processing unit 10 uses the calibration data already stored and held in the memory 11 in the calibration operation to perform data calibration for removing the variation in the reception level based on the reflected wave on the ground surface from the reception level signal. Perform processing.

That is, as shown in FIG. 6, for example, S1
When the reception level signal obtained at the point is v, the altitude signal is assumed to be h1, the signal processing unit 10, FIG. 5 the altitude signal h ₁ by the reference to the data shown in (C)
Recognizing that the reflected wave reception level signal from only the ground to v is v1, the reception level signal v at the point S1 is recognized.
Is subtracted from the reception level signal v1 in the calibration data to obtain a true reception level signal vk, which is used as detection data. This process is performed over the entire scan area, and FIG.
The detection data shown in C is obtained. This data calibration process is a process of subtracting the reflected wave component from only the ground represented by a function of the altitude of the ground scanner 8 from the reception level signal including all the reflected wave components of the unmodulated radio wave detected by the ground scanner 8. Accordingly, the unnecessary reflected wave from the ground can be removed without damaging the reflected wave component from the buried object Q regardless of the ground surface condition (concavo-convex condition) of the ground. When the detection data is obtained as described above, the signal processing unit 10 displays the detection data on the data display unit 13, and when the detection data includes data indicating the presence of the buried object Q, the alarm display unit 14 is displayed. An audible and / or visual alarm is displayed.

Next, a second embodiment will be described.

In the second embodiment, as shown in FIG. 2, a plurality of (N) ground scanners 8 are provided (symbols 81 to 81).
Shown as 8N. ), The ground scanners 81 to 8N are provided with antennas 31 to 3N, ultrasonic radiators 61 to 6N and ultrasonic receivers 71 to 7N, respectively. Further, the plurality of ground scanners 81 to 8N are normally arranged at equal intervals on a straight line orthogonal to the scanning direction.

Due to the plurality of ground scanners 8, the antennas 31 to 3N in the ground scanners 81 to 8N,
A ground scan switching unit 16 for sequentially switching and controlling the ultrasonic radiators 61 to 6N and the ultrasonic receivers 71 to 7N to the circulator 4, the pulse signal transmitter 5, and the altitude measuring unit 9, respectively.
Is also provided, and a distance sensor 17 whose operation is clarified in the explanation of the operation described later is provided.

Other than the above construction, the first structure shown in FIG.
The structure of the altitude measuring unit 9 is the same as that of the embodiment, and the structures of the ground scanners 81 to 8N are the same as those shown in FIG.

The ground scanners 81 to 8N are mounted on a traveling vehicle, and the mounting directions are orthogonal to the traveling direction of the vehicle, and are arranged at equal intervals on a straight line. The sensor 17 is attached. As the distance sensor 17, for example, a rotary encoder is used.

Further, in order to correspond various kinds of processing in the signal processing unit 10 and data (signal) input from each of the ground scanning machines 81 to 8N, the operation time reference of the signal processing unit 10 and the ground scanning. The operating time reference of the switching unit 16 is the same, and therefore, the same clock pulse is supplied to each of them from one clock oscillator 12.

The calculation process of the calibration data and the data process at the time of detecting the buried object are basically the same as those of the first embodiment when viewed from each of the ground scanners 81 to 8N. That is, in the second embodiment, the detection operation is simultaneously performed along the N scanning lines (tracks) on the scanning ground, and the switching speed in the ground scanning switching unit 16 is made higher than the speed of the traveling vehicle. As a result, the same result as when N underground buried object detection devices of the first embodiment are used side by side is obtained.

Further, in the second embodiment, each ground scanner 81
By continuously displaying the detection data obtained at 8N on the data display unit 13 with the movement distance signal obtained from the distance sensor 17 as an axis, the outline of the shape of the buried object can be known.

That is, as shown in FIG. 7, when the buried object Q has a disk shape, for example, each of the ground scanners 81-81.
If the data from 8N (data of each track) is three-dimensionally displayed in correspondence with the distance signal output from the distance sensor 17, the peripheral shape of the embedded object Q is roughly displayed.
It is possible to judge whether the detected buried object is the intended one.

[0055]

As described above, according to the present invention, the reception level of the reflected wave obtained by scanning the ground is shown in advance, which shows the relationship between the altitude of the ground scanning means and the reception level. This is the detection data corrected by the calibration data. By the correction processing, the change in the reception level due to the unnecessary reflected wave from the ground can be effectively removed, and the reflected wave from the underground buried object can be received. Since the level is not lowered by the correction processing, the S / N ratio is dramatically improved as compared with the conventional case, and the underground buried object can be reliably detected.

Since the calibration data is data associated with the altitude of the ground scanning means from the ground surface, the amount of change in the reception level due to the unevenness of the ground surface is corrected once by the relationship with the altitude. The data processing becomes extremely easy.

Further, a plurality of ground scanning means are used to simultaneously scan the ground along a plurality of tracks, the moving distance of the scanning means is also measured, and the plurality of tracks corresponding to the moving distances are measured. Since the outline shape of the buried object can be displayed by simultaneously displaying the above-mentioned detected data, it can be easily determined whether or not the detected buried object is the intended one.

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention.

FIG. 2 is a block diagram of a second embodiment of the present invention.

FIG. 3 is a block diagram of an altitude measuring unit 9 in FIGS. 1 and 2.

4A is a perspective view of a ground scanner 8 according to an embodiment of the present invention, and FIG. 4B is a sectional view taken along line AA in FIG.

5A to 5C are views for explaining a calibration data calculation process.

FIG. 6 is an operation explanatory diagram of the first embodiment.

FIG. 7 is an operation explanatory diagram of the second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... High frequency transmitter 2 ... High frequency receiver 3,31-3N ... Antenna 5 ... Pulse signal transmitter 6,61-6N ... Ultrasonic wave radiator 7,71-7N
... Ultrasonic receivers 8,81 to 8N ... Ground scanner 9 ... Altitude measuring unit 10 ... Signal processing unit 11 ... Memory 13 ... Data display unit 14 ... Alarm display unit 16 ... Ground scan switching unit 17 ... Distance sensor 901 ... Ultrasonic receiver 902 ... S / R
Flip-flop 905 ... Counter 906 ... D / A
Converter 801 ... Electromagnetic horn 802 ... Power resonance rod 805, 806 ... Ultrasonic transducer 807, 808
… Ultrasonic horn

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koushi Shibata 2-5-7 Koishikawa, Bunkyo-ku, Tokyo Meisei Electric Co., Ltd. (72) Fumio Kosuge 2-5-7 Koishikawa, Bunkyo-ku, Tokyo Meisei Electric Within the corporation

Claims (11)

[Claims] 1. An unmodulated radio wave is radiated from the ground scanning means toward the ground while the ground scanning means scans the ground in the horizontal direction, a reflected wave of the unmodulated radio wave on the ground is received, and the reflected wave is received. In the underground buried object detection method in which the underground buried object is detected by analyzing the reception level of, the reception level of the reflected wave is measured and the altitude of the ground scanning means from the ground surface is measured. , The ground scanning means is vertically displaced in the buried object non-buried area in the underground buried object detection area, the reception level change of the reflected wave at that time and the altitude change of the ground scanning means are measured in advance, and The correlation is calculated and stored as calibration data, and the reception level signal of the reflected wave obtained by the ground scanning in the horizontal direction by the ground scanning means in the detection area and the altitude signal of the ground scanning means are By processing on the basis of the calibration data, the reception level correction data is obtained by removing as much as possible the reception level variation due to the unwanted reflection wave from the ground surface of the unmodulated radio wave from the reception level signal, and the reception level Underground object detection method that detects the presence of underground objects from level correction data. 2. The underground buried object detection system according to claim 1, wherein the measurement of the reception level of the reflected wave and the measurement of the altitude of the ground scanning means are set at a plurality of points arranged side by side in a direction orthogonal to the ground scanning direction. Simultaneous scanning in the horizontal direction,
The scanning movement distance of the ground scanning means is measured, and the underground level of the buried object is determined from the reception level correction data obtained for each of the plurality of scanning points and the movement distance data obtained by the scanning movement distance measurement. Underground object detection method that detects the presence and shape of the object. 3. The altitude signal of the ground scanning means is based on the time difference from the time of emitting the ultrasonic pulse signal emitted from the ground scanning means to the time of receiving the reflected wave of the ultrasonic pulse signal on the ground surface. Claim 1 or Claim 2 adapted to obtain
Underground object detection method described in. 4. A first transmitter that outputs an unmodulated high-frequency signal, and a transmitting antenna that emits an unmodulated radio wave toward the ground when the unmodulated high-frequency signal is supplied from the first transmitter. , A receiving antenna in which reflected waves from the ground surface and underground of the unmodulated radio wave radiated from the transmitting antenna are incident to generate an unmodulated high frequency signal, and an unmodulated high frequency signal from the receiving antenna Then, the first receiver that outputs the reception level signal, the second transmitter that outputs the transmission pulse signal, and the transmission pulse signal supplied from the second transmitter, are transmitted toward the ground. An ultrasonic wave radiator that emits an ultrasonic pulse signal, and an ultrasonic wave receiver that generates an ultrasonic pulse signal by receiving a reflected wave on the ground surface of the ultrasonic pulse signal emitted from the ultrasonic wave radiator. , The ultrasonic pulse signal from the ultrasonic receiver A second receiver for receiving and outputting a reception pulse signal; a ground scanner equipped with the transmitting antenna, the receiving antenna, the ultrasonic radiator and the ultrasonic receiver; and the second scanner. An altitude calculator for calculating an output time difference between a transmission pulse signal output from a transmitter and a reception pulse signal output from the second receiver to obtain an altitude signal from the ground surface of the ground scanner; A first memory for storing a reception level signal of a reflected wave of the unmodulated radio wave output by the first receiver, and a second memory for storing an altitude signal of the ground scanner output by the altitude calculating section, The detection is performed by processing the reception level signal stored in the first memory and the altitude signal stored in the second memory by the measurement performed by moving the ground scanner up and down at a buried object-free location in the area. The above reception level signal in the area A calibration data calculation unit for obtaining the calibration data of the number, a third memory for storing the calibration data output by the calibration data calculation unit, and a scanning of the ground scanner along the ground surface in the detection area. Processing the reception level signal stored in the first memory and the altitude signal stored in the second memory based on the calibration data stored in the third memory, A data processing unit that removes as much as possible the reception level change due to unnecessary reflected waves from the ground surface of the radio wave, and extracts the reception level change due to the presence of an underground buried object of the unmodulated radio wave, and the data processing unit An underground buried object detection device comprising a display unit that displays output reception level change data as detection data. 5. The underground buried object detecting apparatus according to claim 4, wherein a plurality of ground scanners are arranged side by side in a horizontal direction orthogonal to the scanning direction, and each antenna is provided with a transmitting antenna and a receiving antenna. A switching control unit for sequentially switching and connecting an antenna, an ultrasonic radiator and an ultrasonic receiver to a first transmitter, a first receiver, a second transmitter and a second receiver, respectively, and the above ground scanning The data processing unit further includes a distance sensor for measuring a horizontal scanning movement distance of the machine, and in the data processing unit,
Receiving level change data is calculated for each, and the receiving level change data is displayed in parallel on the display unit with the moving distance data output by the distance sensor as an axis to display the shape of the buried object. Object detection device. 6. A circulator is interposed between the output of the first transmitter and the input of the first receiver so that one antenna serves as both the transmitting antenna and the receiving antenna. The underground buried object detection device according to claim 4 or claim 5. 7. An ultrasonic oscillating device and an ultrasonic sensitizing device are combined into one ultrasonic oscillating device by interposing a switching means between the output of the second transmitter and the input of the second receiver. The underground buried object detection device according to claim 4 or 5, which is also used. 8. The underground buried object detection device according to claim 4 or 5, which has both the configuration of the antenna according to claim 6 and the configuration of the ultrasonic vibrator according to claim 7. 9. When the reception level change data output from the data processing section includes a level change indicating the presence of an embedded object, an audible and / or visual display means for issuing an alarm is replaced with the display section, or displayed. The underground buried object detection device according to claim 4 or 5, which is provided with the section. 10. The traveling vehicle is provided with a plurality of ground scanners arranged side by side on a horizontal straight line orthogonal to the traveling direction of the traveling vehicle, and a distance sensor is provided in association with the axle of the traveling vehicle. The buried object detection device according to item 5. 11. A ground scanner for use in the underground buried object detection apparatus according to claim 4, wherein the unmodulated high-frequency signal from the first transmitter or / and the ground is used. A resonator that resonates with the reflected wave of, and an antenna for transmission and an antenna for reception or an antenna for both transmission and reception that are composed of an electromagnetic horn that contains the resonator, and a member with a dielectric constant as low as possible. An ultrasonic radiator and an ultrasonic sensing device which are composed of an ultrasonic horn mounted inside the electromagnetic horn with its direction aligned with the opening direction of the electromagnetic horn, and an ultrasonic transducer mounted at the base of the ultrasonic horn. Scanner having an ultrasonic vibrator that also serves as a detector or ultrasonic radiation.