JP3030454B2 - Underground identification device - Google Patents

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 discriminating apparatus capable of specifying the type of an underground buried object with high accuracy and stability by utilizing an elastic wave inherent to a substance.

[0002]

2. Description of the Related Art Conventionally, a detection method using electromagnetic waves or ultrasonic waves has been employed to detect underground objects. In these detection methods, electromagnetic waves or ultrasonic waves are transmitted from the ground surface toward the ground to detect reflected waves or refracted waves due to the buried object, and the position and size of the buried object are buried. Information such as the material can be obtained, but information such as the material for specifying the type of the underground object cannot be obtained. As another method of detecting an underground object, it is possible to detect an underground object using a metal detector using magnetism or the like.However, in such a metal detector, the underground object is made of metal. It can only be detected if it can, for example non-magnetic materials such as plastics and glass.

[0003] Further, as a conventional technique capable of specifying the type of an object to be buried, a probe penetrates into the ground, and the operator feels the impact when the penetrated probe is struck and the degree of slip of the probe. Although there is a method of identifying itself, since the identification accuracy is determined by the subjectivity of the operator, it is difficult to identify the type of the embedded object stably. In addition, since the judgment is performed by a person, it takes time, and it hinders labor saving and labor saving of the identification work. In order to solve such inconveniences, objective identification using a recognition device as shown in FIG. 16 can be considered.

FIG. 16 is a block diagram showing a schematic configuration of a conventional pattern recognition apparatus 1. As shown in FIG. Input patterns such as images and sounds are given to the feature extracting means 2. The feature extracting means 2 extracts a feature amount characterizing the pattern from the input pattern. The feature amount is, for example, an image, which is an essential information used to express an image pattern more simply and to be used for identification described later. The feature vector having the extracted feature amount as an element is
Given to.

[0005] The identification means 3 calculates and outputs, based on the input feature vector, a category vector representing which of the plurality of predetermined types of categories the input pattern belongs to. The identification means 3 is realized by a neural network in which the relationship between the feature vector and the category vector has been learned in advance. The calculated category vector is provided to the identification result determination means 4. The identification result determination means 4 determines the category to which the input pattern belongs based on the given category vector, and outputs the determined category as the identification result. The identification result is provided to the output means 5. Identification means 5
Is realized by a display device such as a CRT (cathode ray tube), and is configured to display an identification result and allow an operator to recognize the identification result.

The neural network used for the identification means 3 is, for example, a known back propagation neural network (hereinafter referred to as BPN).
N). About this BPNN, "Nature vol.323 9 p536-553 (Oct.1986) Learnnin
g Representations by backpropagation errors. "

[0007] Such a BPNN comprises an input layer, an output layer and one or more intermediate layers, each of which is constituted by a plurality of node groups. In the identification by the neural network, for example, in the case of a general configuration in which each node of the output layer of the neural network is associated with a category to be identified on a one-to-one basis, a maximum value is output among a plurality of nodes constituting the output layer. The category corresponding to the node being identified is used as the identification result.

As an input pattern input to the feature extracting means 2 of the pattern recognition device 1 as described above, an elastic wave signal detected by the underground object identification device 7 shown in FIG. 17 is used. The identification device 7 applies vibration to the underground object 8, receives elastic waves generated by the vibration of the underground object 8, and identifies the type of the underground object 8 from the elastic wave. Be composed. In the identification device 7, first, an excitation probe 9 for applying vibration to the underground object 8 and a vibration receiving probe 10 penetrate into the underground 11 until it comes into contact with the underground object 8. An elastic wave generated by the vibrating probe 9 vibrating the underground object 8 is received by the vibration receiving probe 10, and the type of the underground object 8 is identified by identifying the elastic wave. At the upper end 13 of the vibrating probe 9 provided in the first housing 12, the bottom of the underground object 8 is set to 0.1 mm.
Oscillation source 1 for applying an impact of 1 kgf to 0.3 kgf
4 are provided. The lower end 15 of the vibrating probe 9 penetrates into the underground 11 until it comes into contact with the buried object 8, and the impact given to the vibrating probe 9 by the oscillation source 14 is applied to the vibrating probe 9. The light propagates through the probe 9 and is transmitted to the underground object 8, from which an elastic wave unique to the substance is generated.

An acceleration sensor 18 is provided on the upper end 17 of the vibration receiving probe 10 provided in the second housing 16. Further, the lower end 19 of the vibration receiving probe 10 is in contact with the underground object 8, and the elastic wave generated in the underground object 8 moves the vibration receiving probe 10 from the lower end 19 to the upper end 17. Propagation, detection by the acceleration sensor 18, conversion into an electric signal, and feature extraction means 2 as the input pattern
Is input to

In such an identification device 7, the first
The second housings 12 and 16 are fixedly connected to each other, and the vibrating probe 9 and the vibrating probe 10 are solid bars made of metal. The oscillation source 14 is supported by the first housing 12, and the acceleration sensor 18 is supported by the second housing 16.

[0011]

In the prior art shown in FIG. 17, since the vibrating probe 9 and the vibrating probe 10 are solid rods, the oscillation source supported by the first housing 12 is used. The vibration generated by the probe 14 propagates from the upper end 13 to the lower end 15 of the excitation probe 9 as indicated by an arrow A1 and propagates through the underground object 8 as indicated by an arrow A2. Further, the vibration receiving probe 10 is moved from the lower end 19 to the upper end 1.
7 and is detected by the acceleration sensor 18 as indicated by an arrow A3. At this time, the vibration of the oscillation source 14 propagates from the first housing 12 to the second housing 16 as shown by an arrow B, and the vibration from the excitation probe 9 to the vibration receiving probe 10 through the underground 11 through the arrow. The vibration propagates as shown by the symbol C.
Is detected by The electric signal of the acceleration sensor 18 includes the vibration B propagating from the first housing 12 to the second housing 16 and the vibration propagating from the excitation probe 9 to the vibration receiving probe 10 through the underground 11. C is included as noise, so that a good signal-to-noise ratio S / N cannot be obtained, and the type of buried object cannot be quickly and accurately identified.

Accordingly, an object of the present invention is to provide an underground buried object identification device capable of quickly and accurately identifying the type of buried object with improved S / N.

[0013]

According to the first aspect of the present invention, there is provided a vibration probe which is inserted into the ground until one end of the probe contacts an underground object. Vibrating means for propagating vibration applied from the other end to the one end and vibrating the underground object, and a vibration receiving probe inserted into the ground until one end abuts the underground object. A receiving means for receiving an elastic wave propagated to the other end of the receiving probe and outputting an elastic wave signal, and identifying a type of the object buried in the ground from the elastic wave signal output by the receiving means Signal processing means for generating a vibration identification signal for performing the processing, a database section in which buried object data relating to various buried objects are stored, a vibration identification signal input from the signal processing means, and a buried object data input from the database section. To identify the type of buried object based on the vibration identification signal. The vibrating probe includes a striking core that propagates the vibration applied from the other end to one end, and a sheath tube in which the striking core is stored in a non-contact manner over substantially the entire length. The underground object identification device is characterized in that a return means is provided in the sheath tube for returning the hitting core projecting from the sheath tube to an initial position and holding the same.

According to the present invention, the vibrating probe provided in the oscillating means is configured so that the percussion core is stored in a non-contact manner over substantially the entire length by the sheath tube. It is prevented from propagating to the vibration receiving means via a part other than the middle buried object, whereby the noise of the elastic wave signal output from the vibration receiving means can be reduced and the S / N can be improved. Based on the elastic wave signal from such a receiving unit, the signal processing unit creates a receiving identification signal for identifying the type of the underground object, and relates to the receiving identification signal and various embedded objects stored in the database unit. By comparing the data with the buried object by the identification means, the type of the buried object can be quickly and accurately identified.

[0015] The identification means is specifically realized by a neural network. The neural network includes an input layer having a plurality of input sections, an output layer having a number of output sections corresponding to the type of the underground object, and one or more interposed between the input layer and the output layer. And an intermediate layer. By using such a neural network, it is easy to change the number of input data to the input layer and the number of output data from the output layer, and to train the neural network even when erroneous identification is performed. Therefore, correct identification can be performed from the next time, and the identification accuracy can be further improved.

[0016]

A return means is provided in the sheath tube, and the return means can return the hitting core projecting from the sheath tube to the initial position and hold it. By such a return means, the end of the impact core is selected so as not to protrude from the sheath tube, for example, by selecting such that the end surface of one end of the sheath tube and the end surface of one end of the impact core are flush. It is possible to prevent earth and sand from entering the sheath tube when inserting the oscillating probe into the ground, and to prevent deformation of the tip at one end side of the hitting core due to impact and deformation of the tip during transportation. The impact core is prevented from interfering with the sheath tube, and the vibration given to the impact core is prevented from being transmitted to the sheath tube. Can be detected.

According to a second aspect of the present invention, in the configuration of the first aspect, the hitting core is provided in the sheath tube with a short portion including one end, and the hitting core is coaxially arranged with the short portion. And a return portion provided between the short portion and a sheath tube surrounding the short portion.

According to the present invention, the hitting core has a structure divided into a short part and a long part, and the return means is provided between the short part and the sheath tube. Therefore, one end protruding from the sheath tube by the impact is a short portion, and the most susceptible portion of the impact core is projected from the sheath tube to vibrate the underground object. Therefore, the long part is hard to be damaged, and even if it is damaged, only the short part needs to be replaced, the replacement part due to wear or damage can be reduced, the work efficiency at the time of replacement is improved, and the entire impact core is It is possible to improve the economic efficiency as compared with the case of replacing.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a front view of a part of an underground object identification device 31 showing an embodiment of the present invention.
The identification device 31 includes a vibration unit 32, a vibration receiving unit 33, a signal processing unit 34, a database unit 35, and a display unit 37.
including.

The vibrating means 32 has a lower end 38 which is one end.
A rod-shaped vibrating probe 41 inserted into the ground 40 until it comes into contact with the underground object 39, and an oscillation source 43 provided at an upper end 42 which is the other end of the vibrating probe 41. Have. The impact applied downward by the oscillation source 43 along the axial direction of the excitation probe 41 propagates through the excitation probe 41 and is transmitted to the underground object 39. Generates an elastic wave unique to the substance. The vibrating probe 41 includes a striking core 44 for transmitting the vibration from the oscillation source 43 applied from the upper end portion 42 to the lower end portion 38, and a substantially straight line surrounding the striking core 44 in a non-contact manner over substantially the entire length. A cylindrical sheath tube 45.

The vibration receiving means 33 has a lower end 48 which is one end.
Is inserted into the underground 40 until it comes into contact with the underground buried object 39, and is provided at an upper end 50 which is one end of the probe 49. An acceleration sensor 51 that detects an elastic wave propagated to the unit 50 and outputs an elastic wave signal.

The elastic wave signal output from the acceleration sensor 51 is input to the signal processing means 34. Signal processing means 34
Then, a vibration identification signal for identifying the type of the underground object 39 is created from the elastic wave signal, and is output to the identification means 36. In the database unit 35, buried object data relating to various buried objects is stored in advance. Identification means 36
Compares the received identification signal input from the signal processing means 34 with the embedded object data input from the database unit 35, identifies and identifies the type of the embedded object based on the received identification signal, and converts the identification signal into, for example, a liquid crystal. Output to display means 37 realized by the display device.

The vibration receiving probe 49 has a solid rod shape, and the vicinity of its upper end 50 is connected to the lower end 54 of a solid mounting rod 53 by connecting means 52. Mounting rod 5
3 is fixed to the lower portion of the bracket 56.

Between the two ends of the sheath tube 45 and the vibration receiving probe 49, penetrating vibrators 57a and 57b are provided, respectively. Each of the penetrating vibrators 57a and 57b is realized by an air vibrator, and vibrates the vibrating probe 41 and the vibrating probe 49 in each plane including the axis of the sheath tube 45 and the vibrating probe 49. Or the lower end 3 of the sheath tube 45 and the vibration receiving probe 49 in a plane perpendicular to each axis.
Vibration can be applied so that 8, 48 makes a circular motion.

When the vibrating probe 41 and the receiving probe 49 penetrate into the underground 40 in this manner, each of the penetrating vibrators 5
Since vibration is given by 7a and 57b, when the lower ends 38 and 48 come into contact with each other, vibration is given to the particles, and the probes 41 and
The adhesive resistance and frictional resistance between the soil 49 and the soil can be reduced, and the force for penetrating the underground 40 can be reduced.

As described above, the vibration receiving probe 49 is configured to be connected to the mounting rod 53 by the connecting means 52, so that the axis from the lower end portion 48 to the upper end portion 50 of the vibration receiving probe 49 is formed. The length in the direction can be short, so that the damping of the vibration from the lower end portion 48 to the upper end portion 50 at the time of impact is smaller than that in the case where the lower end portion 48 and the bracket 56 are constituted by a single rod. At the same time, mixing of noise is reduced, and the accuracy and reliability of vibration by the acceleration sensor 51 can be improved.

FIG. 2 is a sectional view showing the internal structure of the vibration means 32 shown in FIG. 1, FIG. 3 is an exploded perspective view of the vibration probe 41, and FIG. FIG. The vibration means 32 has the vibration probe 41 and the oscillation source 43 as described above. The excitation probe 41 has a hollow stainless steel sheath tube 45 and a stainless steel hitting core 44 inserted into the sheath tube 45. Sheath tube 4
5, internal threads 61 and 62 are engraved on the inner peripheral parts at both ends in the axial direction, and a straight cylindrical inner periphery having an inner diameter through which the striking core 44 can pass is provided between the internal screws 61 and 62. A surface 63 is formed.

The striking core 44 inserted into the sheath tube 45 is disposed in the sheath tube 45 on the side of the lower end portion 38 and a short portion 64 and substantially coaxially with the short portion 64. It has a configuration that is divided into a long portion 65 disposed on the upper end portion 42 side. This short portion 64
Has a short rod-shaped body 66 having a right columnar shape, and a disk-shaped head 67 fixed coaxially to one end of the short rod-shaped body 66 in the axial direction, for example, by welding. The long part 65 is
A long rod 68 having a right columnar shape and a shaft joint 69 coaxially fixed to one end of the long rod 68 in the axial direction by, for example, welding. The length of the short portion 64 in the axial direction is, for example, 72 mm, and the length of the long portion 65 in the axial direction is, for example, 448 mm. Also, a short rod 66
Each outer diameter of the long rod-shaped body 68 is selected to be 2.0 mm.

The sheath tube 45 includes a guide cap 71 having an insertion hole 70 through which the short rod 66 of the short portion 64 is movably inserted in the axial direction. The guide cap 71 has a frusto-conical guide part 72 and a coaxially integral part of the guide part 72, and has a straight cylindrical sheath tube body 46.
And a screw portion 73 that is screwed to the inner screw 62 on the lower end side. The insertion hole 70 is formed coaxially in communication with the guide portion 72 and the screw portion 73.

The guide cap 71 of the sheath tube body 46
A pair of screw holes 74 in the direction of one diameter line
Are formed, and a bolt 75 is screwed into each screw hole 74. Bolts 75 screwed into the respective screw holes 74 project radially inward from the inner peripheral surface 63 of the sheath tube main body 46. The short portion 64 and the compression coil spring 76 are housed in a space below each bolt 75 in the sheath tube main body 46, and the guide cap 71 is screwed thereto.
In this state, one end of the compression coil spring 76 resiliently abuts the head 67 of the short portion 64 from below, and the other end of the compression coil spring 76 has the guide cap 71 screwed to the sheath tube body 46. It resiliently comes into contact with the end face 77 of the screw portion 73. Accordingly, as shown in FIG. 2, the short portion 64 is pushed upward by the compression coil spring 76 and is brought into contact with each bolt 75 and locked.

The long rod-shaped body 68 of the long portion 65 is inserted into the insertion hole 79 of the holder 78, and is inserted into the insertion hole 79 of the holder 78 and protrudes downward from the holder 78.
A plurality (four in this embodiment) of synthetic resin sliding rings 8
1 are fixed at equal intervals in the axial direction of the elongated rod 68. Each slide ring 81 has an annular shape, has an insertion hole 82 through which the long rod-shaped body 68 can be inserted, and a bolt is screwed into a screw hole (not shown) formed in one radial direction. Thereby, each sliding ring 81 is fixed to the elongated rod 68. Each such sliding ring 81 guides the elongated portion 65 coaxially within the sheath tube main body 46 in a state of being in contact with the inner peripheral surface 63 within the sheath tube main body 46 so as to be able to move smoothly in the axial direction. can do.

The holder 78 has a shaft portion 83 in which an insertion hole 79 is formed, and a flange 84 integrally formed at an intermediate portion between both ends of the shaft portion 83 in the axial direction. Shaft 8
An outer screw 85 is engraved at one end in the axial direction of the third tube 3. The outer screw 85 is screwed into an inner screw 61 formed at the upper end of the sheath tube main body 46, and is held at the upper end of the sheath tube main body 46. The body 78 is screwed.

A pair of screw holes 74 formed in the sheath tube main body 46 and a pair of bolts 7 screwed into the respective screw holes 74
5. The return means 86 is constituted by including the head 67 of the short portion 64, the compression coil spring 76, and the guide cap 71. By such a return means 86, the vibration probe 41 is inserted into the ground in a state where the hitting core 44 does not protrude from the sheath tube 45, and thus the short rod-like body 66 does not protrude from the guide cap 71, and the hitting is performed. The core 44 is prevented from being deformed or damaged, and the intrusion of earth and sand into the sheath tube 45 is prevented, so that the striking core 44 can move smoothly, and attenuation due to the dispersion of the striking force is prevented. In addition, the short portion 46 is maintained in a state where the one end portion 87 in the axial direction of the short rod body 66 does not protrude from the end face of the one end portion 88 in the axial direction of the guide cap 71, that is, the initial position. At this time, the long portion 65 has one end 89 in the axial direction at the lower end thereof and the head 6 of the short portion 64.
7 are spaced apart from each other at an interval ΔL in the axial direction. This interval ΔL is selected, for example, to be 10 mm.

In this manner, the head 67 of the short portion 64
By striking the long portion 65 in a state where it is separated upward, a striking force can be instantaneously applied to the short portion 64, and the long portion 65 is connected to the below-described pneumatic cylinder 9.
4, the short portion 64 is returned by the return means 86 immediately after the impact, and the reaction of the impact force caused by the contact between the short portion 64 and the long portion 65 is transmitted to the sheath tube 45. Inconvenience is prevented.

Referring to FIG. 2 and FIG.
3 includes a housing 93, a pneumatic cylinder 94 for striking which is housed in the housing 93 and generates a striking force by driving the long portion 64 in the axial direction, and a vibration isolating means 95. The housing 93 includes a box-shaped housing body 96.
And a thin-plate lid 9 for closing the opening of the housing body 96.
7 and a plurality (four in this embodiment) of bolts 98 for detachably attaching the lid body 97 to the housing body 96. The housing body 96 has a through hole 101 through which a shaft portion 83 of the holder 78 can pass through a bottom plate 99 below in FIG. 2, and a left side wall 102 of the bottom plate 99 in FIG. And a mounting hole 104 in which a connector 103 for supplying compressed air to the striking pneumatic cylinder 94 is mounted, and a bottom plate 99 is formed at the center of an upper plate 105 facing the vertical direction in FIG. Piston rod 10 of underground insertion cylinder not shown
6 is inserted through the lower end portion thereof and is fixed in a state where the upper plate 105 is sandwiched by two nuts 107.
Is formed. Note that a piston rod is similarly connected to the bracket 56.

In the interior space of the housing body 96, the mounting bracket 109 and the bolt 11
With 0, the impact pneumatic cylinder 94 is attached. Compressed air is supplied to the striking pneumatic cylinder 94 through a compressed air supply pipe 111 extending from above the connector 93, and the piston rod 112 of the striking pneumatic cylinder 94 is connected to the shaft coupling 69 of the elongated portion 65. Linked to The striking pneumatic cylinder 94 is realized by a commercially available single-acting spring return screw cylinder.

On the bottom plate 99 of the housing body 96,
An anti-vibration means 95 is provided. The anti-vibration means 95 is provided coaxially so as to surround the through hole 101 of the bottom plate 99, and has a cylindrical body 116 on which an external screw 115 is engraved on an outer peripheral portion.
An inner screw 117 screwed to the outer screw 115 of the cylindrical body 116
And a retaining cap 119 in which a through-hole 118 having substantially the same inside diameter as the through-hole 101 is formed, and a flexible and resilient, for example, an anti-vibration rubber. A pair of annular shock absorbing members 121 and 122 through which the portion 83 is inserted;
Cylindrical sleeve 123 in which is almost exactly stored
And

With the retaining cap 119 screwed to the cylindrical body 116, the holding body 78 is housed in the internal space in a state sandwiched by the respective shock absorbing members 121 and 122.
Each of the shock absorbing members 121 and 122 is inserted into the sleeve 123 together with the holder 78, and the sleeve 123 is stored in the internal space. Such a sleeve 123 prevents the shock absorbing members 121, 122 from being deformed outward in the radial direction from above, whereby the respective shock absorbing members 121, 122 abut against the inner peripheral surface of the cylinder 116. The contact is prevented, and the recoil at the time of impact is prevented from being transmitted to the housing 93 at the time of impact.

FIG. 5 shows an experiment in which an unnecessary elastic wave other than a buried object which becomes noise by vibrating a vibration isolator buried in the ground is measured, and a solid vibration probe is used. FIG. 5 is a graph showing an experimental result by the inventor of the present invention, and FIG.
5 shows the change of the unnecessary elastic wave signal with the lapse of time at the time of impact, and FIG. 5B shows the relationship between the elastic wave intensity normalized to 0 and 1 and the frequency (logarithm). When hitting a vibration-isolating material buried underground with a solid vibration probe as in the past,
The unnecessary elastic wave signal detected by the acceleration sensor 51 is approximately +33 m immediately after the impact as shown in FIG.
V reaches −30 mV, and then attenuates with the passage of time. After about 2000 μsec, the elastic wave signal converges to almost 0 mV. As shown in FIG. 5 (2), it was confirmed that the elastic wave intensity at this time increased at around 200 Hz and 1 kHz when hit with a solid vibrating probe.

FIG. 6 shows a hollow sheath tube 45 according to the invention.
FIG. 6 (1) is a graph showing experimental results by the present inventor when the vibration isolating material buried in the ground is struck using the excitation probe 41 into which the striking core 44 is inserted. FIG. 6B shows an unnecessary change in the elastic wave signal with the passage of time.
Indicates the relationship between the elastic wave intensity normalized to 0 and 1 and the frequency (logarithm). Unnecessary changes in the elastic wave signal caused by the solid vibrating probe shown in FIG. 5 (1) and the vibrating core 44 inserted into the hollow sheath tube 45 shown in FIG. 6 (1). Compared with the change of the unnecessary elastic wave signal when the probe 41 is used, the signal change immediately after the impact when using the excitation probe 41 in which the impact core 44 is inserted into the sheath tube 45 is ± 2. ~ 3mV
And about 1/10 of the solid type, and the convergence time is about 1
/ 2, which is about 1000 μsec. Looking at the frequency spectrum at this time, as shown in FIG. 6 (2), the unnecessary elasticity around 200 Hz and 1 KHz which was obtained when the solid vibration probe shown in FIG. 5 (2) was used. It was confirmed that the waves were reduced. From such experimental results, the impact core 44 is inserted into the hollow sheath tube 45 according to the present invention.
The use of a vibration probe with an inserted probe eliminates noise by eliminating unnecessary vibration transmitted through the housing or other device body and vibration transmitted from the vibration probe to the receiving probe through the soil. However, it was confirmed that good S / N was obtained.

FIG. 7 shows a hollow sheath tube 45 according to the invention.
6 is a graph showing the relationship between elastic wave intensity and frequency as a result of an experiment by the present inventor when a stone plate buried in the ground is struck using a vibration probe into which a striking core 44 is inserted. The present inventor hit a stone plate with the vibration probe according to the present invention instead of the vibration isolating material used in FIGS. 5 and 6. At this time, the frequency is around 500-600 Hz and 2.5 kHz
It was confirmed that the elastic wave intensity increased near. In this experiment, the vibrating probe was brought into contact with a stone buried underground every measurement and the measurement was repeated five times, and it was found that almost the same spectral characteristics were obtained in all of these measurements.

When a stone plate having such elastic wave characteristics is hit with a conventional solid vibrating probe, noise is reduced by 200 as shown in FIG.
In the vicinity of 1 Hz and 1 kHz, the elastic wave characteristic of the stone slab changes greatly. In order to identify the surroundings of an underground object, erroneous judgment is made or the underground object is identified as a slab. However, according to the vibration probe of the inventor of the present invention, it can be understood that the type of the underground object can be quickly and accurately specified.

FIG. 8 is a block diagram showing the electrical configuration of the underground object identification device 31. As shown in FIG. The signal processing means 34
Is a signal amplifier 127, an A / D converter 128, a waveform storage circuit 129, and an FFT (fast Fourier transform) operation circuit 13.
0, and an input vector generation circuit 131. In the signal processing circuit 34, an identification signal for identifying the type of the underground object is created from the received elastic wave. That is, the elastic wave signal converted by the acceleration sensor 51 is input to the signal amplifier 127 and amplified. Also, if necessary,
Unnecessary signals are removed by using a filter including the signal amplifier 127. The signal processed by the signal amplifier 127 is input to an A / D (analog / digital) converter 128 and converted into a digital signal.
The signal is input to the memory 29 and stored (sampled and held) as a time axis response signal.

The time axis response signal stored in the waveform storage circuit 129 is Fourier-transformed by the FFT operation circuit 130 to generate a frequency response signal. This frequency response signal is
The divided response signal divided for each of the plurality of frequency bands is processed by the input vector generation circuit 131. For example, 20
A signal in a frequency band of Hz to 5 kHz is divided into 10 to 100, for example, into 50. These divided signals are divided by the maximum value of each component in data stored in the database unit 132 by learning in advance, and are normalized to values of 0 to 1. The divided response signal thus created is the identification signal.

The identification circuit 36 includes a neural network 133 and an output vector determination circuit 134. As the neural network 133, for example, BPNN
(Back propagation neural network) is used. The divided response signal from the input vector generation circuit 131 is input to the neural network 133, and an output signal for each type of underground object based on the divided response signal is created and supplied to the output vector determination circuit 134. The output vector determination circuit 134 determines the type of the underground object based on the output signal level from the neural network 133.

Waveform storage circuit 129, FFT operation circuit 13
0, each output signal from the input vector generation circuit 131, the neural network 133, and the output vector determination circuit 134 is input to the display processing circuit 135 and subjected to image processing, and the image is processed by the display device 136 realized by, for example, a liquid crystal display device. Is displayed. The display means 37 is configured by the display processing circuit 135 and the display device 136.

FIG. 9 is a diagram showing a schematic configuration of the neural network 133 of the identification means 36. The neural network 133 is the BPNN, and the input layer 1
38, an intermediate layer 139 and an output layer 140. The input layer 138 includes a plurality of nodes NI1 to NIm. The intermediate layer 139 has one or a plurality of layer structures, and each layer includes a plurality of nodes NM1 to NMp. In the present embodiment, the intermediate layer 139 is one layer. The output layer 140 includes a plurality of nodes NO1 to NO
n.

The number of nodes constituting input layer 138 and output layer 140 is determined according to the number of data to be input and the number of data to be output. That is, the number of nodes NI forming the input layer 138 corresponds to the number of divided response signals created by the input vector generation circuit 131. Further, the number of node NOs constituting the output layer 140 is as follows:
This corresponds to the number of types of the underground buried objects 39. For example, the number of nodes NI is selected to be 50, and the number of node NOs is selected to be 4, for example, to identify metal pieces, plastic pieces, stone pieces, and wood pieces, and the number of nodes NM constituting the intermediate layer 139. Is empirically chosen to be 20.

Such a neural network 133
Is used for the learning of the elastic wave signal and the type of the underground object 39 stored in the database unit 132 in advance. The category vector corresponding to the type of the underground object 39 indicates the type to be identified by the output layer 14 of the neural network 133.
This is represented by the state of the node NO of 0. Output layer 14
The node NO of 0 and the category to be identified are associated one-to-one. For example, when learning the category corresponding to the node NOn of the output layer 140, a predetermined feature vector is given to each of the nodes NI1 to NIm of the input layer 138, and the nodes NO1 to N of the output layer 140 are given.
On (Ci (i = n) = 1, Ci (i
カ テ ゴ リ n) = 0 category vectors are given.

FIG. 10 is a diagram for explaining a determination procedure in the output vector determination circuit 134 of the identification means 36. The description will be made on the assumption that four types of buried objects are P, Q, R, and S. Therefore, the neural network 13
The three output layers 140 are composed of four node NO1 to NO4 layers. Four output signals corresponding to the types P to S of the buried objects are output from the neural network 133 and input to the output vector determination circuit 134. Is done. At this time, the one having the maximum output signal level is selected as the identification candidate. In the output vector determination circuit 134, two thresholds T1 and T2 (T1> T2) are set in advance.

As shown in FIG. 10 (1), the output signal level is the maximum, the signal level of Q selected as an identification candidate is T1 or more, and the remaining signal levels of P, R, and S are If T2 or less, Q as the identification candidate is adopted as the type of the buried object. As shown in FIG. 10 (2),
When the signal level of Q is T1 or less and the remaining signal levels of P, R, and S are T2 or less, or FIG.
As shown in (3), the signal level of Q is equal to or higher than T1, and any of the remaining P, Q, and S, for example, P becomes P2
In the above case, Q as the identification candidate is rejected.

The threshold values T1 and T2 are selected empirically. For example, when four output signal levels are close,
If T1 and T2 are set to relatively small values near the output signal level, the selected identification candidate can be adopted. If the difference between T1 and T2 is set to a large value, the selected identification candidate is rejected. Each of the thresholds T1 and T2 is set according to a desired identification accuracy. Such a threshold T
As an instruction for setting 1, T2, for example, T1 = 0.7, T2 = 0.3 with the maximum value of the output signal level being 1,
Can be set in the output level determination circuit 134, respectively.

FIG. 11 shows the display screen 14 of the display device 136.
FIG. 2 is a diagram showing display contents displayed in 1. Display device 13
11, a time waveform display area 143, a frequency spectrum display area 144, 145, and an input vector display area 146 are formed on the display screen 141 of FIG. An embedded object name display area 147, an output vector display area 148, and a neural network configuration display area 149 are formed from top to bottom on the right side of FIG.

In the time waveform display area 143, a waveform based on the time axis response signal from the waveform storage circuit 129 is displayed, for example, a waveform for 0 to 50 msec is displayed. In the frequency spectrum display areas 144 and 145, F
A spectrum based on the frequency response signal from the FT operation circuit 130 is displayed. In one frequency spectrum display area 144, for example, a spectrum between 0 and 10 kHz is displayed, and in the other frequency spectrum display area 145, for example, a spectrum between 20 Hz and 5 kHz is logarithmically displayed.

The input vector display area 146 displays a graph based on a plurality of divided response signals from the input vector generation circuit 131, that is, an input vector input to the neural network 133. In the embedded object name display area 147, a name indicating the type of the embedded object determined by the output vector determination circuit 134 is displayed. The output vector display area 148 includes the neural network 13
The output vectors from 3 are displayed, for example, in a bar graph. In the neural network configuration display area 149,
The configuration of the above-described neural network 133 (see FIG. 9) is displayed.

FIG. 12 is a flowchart showing the procedure of identifying and learning underground objects, and FIG.
FIG. 3 is a diagram showing an example of display by No. 1. In step a1, the elastic wave signal received by the receiving unit 33 is input to the signal amplifier 127 of the signal processing unit 34, converted into a digital signal by the A / D converter 128, and stored in the waveform storage circuit 129 as a time-base response signal. Is stored as Step a
In 2, the time axis response signal stored in the waveform storage circuit 129 is Fourier-transformed by the FFT operation circuit 130 to generate a frequency response signal. The input vector generation circuit 13
In step 1, a plurality of divided response signals are created. Step a3
Then, the received elastic wave signal is stored in the database unit 132. By storing the information in the database unit 132, the neural network 1
33 can be re-learned.

At step a4, it is determined whether the mode is the identification mode or the learning mode. If the mode is the identification mode, the process proceeds to step a5. If the mode is the learning mode, the process proceeds to step a9. In step a5, the divided response signal created by the input vector generation circuit 131 is input to the neural network 133 and subjected to neural network identification processing. In step a6, the output signal from the neural network 133 is input to the output vector determination circuit 134, and the identification result is determined. In step a7, the display device 136 displays, for example, the display content of the display screen 141 shown in FIG. Step a
In step 8, it is determined whether or not the process has been completed. If not, the process returns to step a1.

If the learning mode is set in step a4, the process proceeds to step a9, where the elastic wave signal stored in the database 132 is read out in step a3 and used for learning of the neural network 133. In step a10, the neural network 133 learns the relationship between the read elastic wave signal and the type of the buried object corresponding to the elastic wave signal. When this learning process ends, the process returns to the step a8. The learning mode can be executed before performing the identification, and can also be executed when the identification is performed and the result of the identification is incorrect. An error in the identification result is determined by the operator. By having the learning mode as described above, the discrimination ability can be further improved.

FIG. 14 is a sectional view of a vibrating means 32a showing another embodiment of the present invention. Note that the same reference numerals are given to portions corresponding to the above-described embodiment. In the above-described embodiment, the oscillation source 43 is driven by the vibrating probe 4 by air pressure.
In this embodiment, the motor 151 is used, though it is configured to hit 1. A cam 153 is fixed to an output shaft 152 of the motor 151.
The hammer 155 is lifted upward by the cam surface 154. When the hammer 155 reaches the top dead center, the cam 1
The cam surface 154 of the 53 comes off the hammer 155 and is pressed downward by the compression coil spring 156 to strike the contact piece 157 of the vibration probe 45 a fixed to the upper end of the long portion 65. The rotation position of the cam 153 is detected by a detection switch 158, and the motor 151 stops at each rotation according to a detection signal from the detection switch 158. The detection switch 158 is realized by, for example, a micro switch, and the motor 151 is, for example, a synchronous motor with a speed reducer.

The impact force of the hammer 155 on the contact piece 157 is determined by the spring force of the compression coil spring 156 and the hammer 15.
5 and the amount of rise of the hammer 155 by the cam 153. Motor 151 and cam 15 described above
3. The hammer 155 and the compression coil spring 156 are housed in the housing 159. At the bottom of the housing 159,
An anti-vibration means 95 having a configuration similar to that of the above-described embodiment is provided.

The vibrating means 32a having such a configuration may be used in place of the vibrating means 32 of the above-described embodiment.

FIG. 15 is a sectional view of a vibrating means 32b showing still another embodiment of the present invention. Note that the same reference numerals are given to portions corresponding to the above-described embodiment. The vibration means 32b of the present embodiment includes an oscillation source 43b having a worm 162 and a worm gear 163 driven by a motor 161, and a vibration probe 41b. A first gear 165 is fixed to an output shaft 164 of the motor 161, and a second gear 166 meshes with the first gear 165. The second gear 166 is fixed to an upper end of the shaft 167, and the shaft 167 is supported by a moving body 169 housed in the housing 168 so as to be displaceable in a direction perpendicular to the axis of the shaft 167. The moving body 169 is provided with engaging claws 170a, 170
b, and each of the engagement claws 170a, 170b
a, 171b. Each engagement piece 171a,
171b is provided on the elevating plate 173 which is elastically pressed downward in FIG. 15 by the compression coil spring 172. At the upper end of the elevating plate 173, a contact portion 174 bent toward the near side perpendicular to the paper surface of FIG. 15 is formed.

The housing 168 has an intermediate wall 1 extending vertically.
75 are provided on the inner wall 175.
Guide rods 177a, 1 with 76a, 176b mounted
77b are provided. Each guide rod 177a,
The reference numeral 177b guides the movable body 169 movably in the left-right direction in FIG. 5 by passing through a through hole formed in the movable body 169.
Each of the compression coil springs 176a and 176b is in a compressed state when the worm gear 163 is engaged with the worm 162, and moves the moving body 169 rightward in FIG. 15, that is, in a direction in which the worm gear 163 separates from the worm 162. Each of the engaging claws 170a and 170b is engaged with and engaged with the engaging pieces 171a and 171b, respectively, and the state in which the worm gear 163 meshes with the worm 162 is maintained. The worm 162 is fixed to a guide cover 179 that displays a hammer 178.

The upper end of the guide cover 179 has a projection 18
When the hammer 178 rises together with the guide cover 179 by the rotation of the worm gear 163, the projection 180 contacts the contact portion 174 of the elevating plate 173 from below and pushes up, and the engaging pieces 171a, 171b Is the engagement claw 17
0a, 170b. Thereby, the moving body 16
FIG. 9 shows a direction in which the compression coil springs 176a and 176b are separated from the inner wall 175 by the spring force of the compression coil springs 176a and 176b.
To the right of the worm gear 163 and the worm 162
Depart from.

When the worm gear 163 separates from the worm 162 in this way, the hammer 178 is pressed downward by the spring force of the compression coil spring 181 together with the guide cover 179, and the abutment provided at the upper end of the elongated rod 68 is provided. The piece 182 is hit. The contact piece 182 and the long rod 68 constitute a long portion 65b.

At the lower part of the housing 168, a mounting cylinder portion 183 having an outer thread engraved on the outer peripheral surface is integrally formed.
The anti-vibration means 95 is provided in the mounting cylinder portion 183 so as to be detachable and replaceable. An operation piece 183 partially protruding from the housing 168 is fixed to the moving body 169, and a switch 185 covered by a cover 184 is provided between the tip of the operation 183 and the housing 168.
The operating piece 183 projects outward when the engaging claws 170a and 170b are disengaged from the engaging pieces 171a and 171b. When the operating piece 183 is pushed, the operating piece 183 is pressed. , 170b are engaging pieces 171
a, 171b is pressed upward, whereby the lifting plate 17
3 is displaced upward against the spring force of the compression coil spring 172, and each engaging piece 171a, 171b is
It fits into 70b and is locked. At this time switch 1
85 conducts in conjunction with the displacement of the operation piece 183, and the motor 1
Drive power is supplied to 61. This allows the output shaft 16
The rotation of No. 4 is transmitted to the shaft 167 via the first and second gears 165 and 166, and the worm gear 163 rotates to move the hammer 178 together with the guide cover 179.

As described above, the projection 1 of the guide cover 179
When the abutment portion 174 of the elevating plate 173 is pressed upward from below as the elevating member 80 rises, the engaging pieces 171a and 171b provided on the elevating plate 173 cause the engaging claws 170a and 170
b from the engaging claws 170a, 170
15B, the operation piece 183 returns to the outside, that is, to the right in FIG.
Is cut off, the supply of the driving power to the motor 161 is cut off, the rotation of the worm gear 163 stops, and the standby state is maintained.

The vibrating means 32b having such an oscillation source 43b may be used in place of the vibrating means 32, 32a.

[0070]

According to the first aspect of the present invention, since the striking core of the vibrating probe is inserted into the sheath tube, the vibration at the time of striking propagates through the soil and the device to the vibrating probe. And thereby reduce noise and reduce S / N
(Signal-to-noise ratio) can be improved, and the type of underground object can be identified quickly with high accuracy.

Further, since a return means for returning the hitting core to the initial position and holding the same is provided in the sheath tube, the hitting core can be inserted into the ground without protruding from the sheath tube. Prevents deformation and damage, and further prevents earth and sand from entering the sheath tube, allowing the striker to be smoothly displaced within the sheath tube, and without damping and dispersing the striking force applied to the striker underground. The vibration can be transmitted to the buried object.

According to the second aspect of the present invention, the impact core is divided into a long portion and a short portion, and the return means is provided between the short portion and the sheath tube. The attenuation of the impact force propagating from the part toward the one end can be reduced, and the underground object can be vibrated accurately with a desired impact force, whereby the type of the underground object can be identified with high accuracy. be able to.

[Brief description of the drawings]

FIG. 1 is a front view of an underground object identification device 31 showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an internal structure of the vibration means 32 shown in FIG.

FIG. 3 is an exploded perspective view of an excitation probe 41.

FIG. 4 is an exploded perspective view of an oscillation source 43.

FIG. 5 is a graph showing an experimental result by the present inventor when a vibration isolating material buried in the ground is vibrated using a solid vibrating probe, and FIG. FIG. 5B shows a change in the elastic wave signal with time, and FIG. 5B shows the relationship between the elastic wave intensity and the frequency.

FIG. 6 shows a percussion wick 4 in a hollow sheath tube 45 according to the invention.
FIG. 6A is a graph showing an experimental result by the present inventor when the vibration damping material buried in the ground is hit by using the vibration probe into which the vibration probe 4 is inserted, and FIG. FIG. 6B shows the relationship between the elastic wave intensity and the frequency.

FIG. 7 shows a percussion wick 4 in a hollow sheath tube 45 according to the invention.
4 is a graph showing the relationship between the elastic wave intensity and the frequency as a result of an experiment conducted by the present inventor when a stone plate buried in the ground is hit by using a vibration probe into which a vibration probe 4 is inserted.

FIG. 8 is a block diagram illustrating an electrical configuration of an underground object identification device 31.

FIG. 9 shows a neural network 133 of the identification means 36.
It is a figure which shows the schematic structure of.

FIG. 10 is an output vector determination circuit of the identification means.
It is a figure for explaining the judgment procedure in.

FIG. 11 is a diagram showing display contents displayed on a display screen 141 of the display device 136.

FIG. 12 is a flowchart showing a procedure for identifying and learning an underground object.

FIG. 13 is a diagram showing an example of display on a display screen 141.

FIG. 14 shows a vibrating means 32 showing another embodiment of the present invention.
It is sectional drawing of a.

FIG. 15 is a cross-sectional view of a vibrating means 32b showing still another embodiment of the present invention.

FIG. 16 is a block diagram showing a schematic configuration of a conventional pattern recognition device 1.

FIG. 17 shows a typical prior art underground object identification device 7
FIG.

[Explanation of symbols]

 31 underground buried object identification device 32, 32a, 32b vibrating means 33 receiving means 34 signal processing means 35 database unit 36 identifying means 37 display means 38 lower end 39 underground buried object 40 underground 41, 41a, 41b vibration Probe 42 Upper end 43, 43a, 43b Oscillator 44 Strike core 45 Sheath tube 46 Sheath tube main body 49 Vibration probe 51 Acceleration sensor 57a, 57b Penetrating shaker 64 Short portion 65, 65a, 65b Long portion 66 Short rod-shaped body 68 Long rod-shaped body 86 Returning means 93 Housing 94 Pneumatic cylinder for impact 95 Vibration isolating means 121, 122 Shock absorbing member

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Fujio Iidaka 1-14-4 Aoba, Sagamihara City, Kanagawa Prefecture (72) Inventor China Kimura 1 Kawasakicho, Kakamigahara City, Gifu Prefecture Kawasaki Heavy Industries Gifu Factory (72 ) Inventor Makino Tatsuo 1 Kawasaki-cho, Kakamigahara-shi, Gifu Prefecture Inside the Gifu Plant, Kawasaki Heavy Industries, Ltd. JP-A-8-105977 (JP, A) JP-A-9-80034 (JP, A) JP-A-9-145848 (JP, A) Jikken 47-38001 (JP, Y1) (58) Int.Cl. ⁷ , DB name) G01V 1/00 G01V 9/00

Claims (2)

(57) [Claims] 1. A vibrating probe inserted into the ground until one end of the vibrating probe comes into contact with an object buried under the ground, and the vibration applied from the other end of the vibrating probe is applied to the one end. A vibrating means for propagating the object to be buried underground and vibrating the underground object, and a vibrating probe inserted into the ground until one end abuts on the buried object, and the other end of the vibrating probe Receiving means for receiving an elastic wave propagated to the portion and outputting an elastic wave signal, and signal processing means for generating a received identification signal for identifying a type of an underground object from the elastic wave signal output by the receiving means. The database unit in which the data of the buried objects relating to various buried objects is stored, the received identification signal input from the signal processing means and the buried object data input from the database unit are compared and collated, and Identification means for identifying and identifying the type, wherein the vibrating probe, A striking core for propagating vibration applied from the other end to the one end, and a sheath tube in which the striking core is stored in a substantially non-contact manner over substantially the entire length; An underground object identification device, further comprising a return means for returning a hitting core projecting from the head to an initial position and holding the same. 2. The hitting core is divided into a short portion including one end and a long portion including the other end coaxially with the short portion in the sheath tube, and the short portion and the short portion are separated. The underground object identification device according to claim 1, wherein the return means is provided between the sheath tube and a sheath tube surrounding the portion.