JP2821544B2 - Borehole scanner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a borehole (in the present invention, a boring hole,
The present invention relates to a borehole scanner (a borehole hole wall observation device) for observing a hole wall by a scanner built in a sonde which moves up and down and translates inside a pipe hole or other holes.

[Conventional technology]

When excavating underground cavities such as dams and tunnels, it is necessary to conduct a geological survey of the construction site and reflect it in the design, as well as to select the construction method to be adopted, how to proceed with the construction, and ensure safety measures etc. . In geological surveys in such cases, it is generally necessary to know the direction, slope and nature of the fractures in the rock, as well as the direction and slope of the formation. For this reason, investigations are being conducted by drilling the construction site and collecting and observing the core, or by directly observing the hole wall of the borehole. In the method of directly observing the hole wall of the borehole, there are borehole, TV, borehole periscope,
Devices such as borehole cameras and borehole scanners are used.

FIG. 8 is a diagram showing a specific configuration example of a conventionally used borehole scanner, and FIG. 9 is a diagram showing a trajectory of a hole wall development surface scanned by a light beam. In the figure, 30 is a main unit, 31 is a winch for winding up a sonde 32,
33 is a turning motor, 34 is a compass, 35 and 42 are lenses, 36
Denotes a mirror, 37 denotes an optical head, 38 and 41 denote slits, 39 denotes a photoelectric converter, 40 denotes a half mirror, and 43 denotes a light source.

In FIG. 8, a main unit 30 captures a signal obtained by an imaging means provided in a sonde 32, and processes the data to generate borehole observation information, such as a monitor of a borehole wall observation image. , A data processing device (computer), a magnetic tape, a storage device such as a floppy disk, a magnetic disk, and an output device such as a printer. As shown in FIG. 3B, an imaging means for obtaining a hole wall observation image is housed in the sonde 32, and the winch 31 raises and lowers the sonde 32.

As shown in FIG. 8 (b), an optical head 37 having a compass 34, a lens 35 and a mirror 36 is connected to a turning motor 33 for the sonde 32 which moves up and down in the borehole. Further, a light source 43 for sending a light beam to the optical head 37 through a half mirror 40, a lens 42 for forming a light beam, a slit 41, and an optical head 37.
And a photoelectric converter 39 for detecting a reflected beam from the device. With such a configuration, the light source 43
Is made into a beam shape by a lens 42 and a slit 41, and is applied to the inner wall of the borehole through a half mirror 40, a mirror 36, and a lens 35. And the intensity of the reflected beam is the lens 35, mirror 36, half mirror 40, slit
It is measured by the photoelectric converter 39 through 38. Therefore, while turning the optical head 37 by the turning motor 33,
When 32 is lowered, an inner wall scan u of the borehole as shown in FIG. 9 is performed, and an electric signal corresponding to the intensity of the reflected beam is obtained from the photoelectric converter 39.

Further, a triangular mirror is rotated in place of the half mirror 40 as described above, and light from a light source is reflected by one side of the triangular mirror to irradiate a wall surface.
The one that reflects the light at the other side of the corner and guides the light to the photoelectric converter has also been put to practical use by the present inventors.

[Problems to be solved by the invention]

However, in the hole wall observation by the conventional borehole scanner as described above, since the mechanical scan method is adopted, there is a problem in the mechanical scan unit that rotates. In other words, the mechanical scanning unit is composed of a turning motor 33, a compass 34, and an optical head 37 having a lens 35 and a mirror 36. Costly. In addition, the device becomes heavy and large because the rotation mechanism is mounted, and the structure becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a borehole scanner which has no moving parts and can observe a hole wall at high speed.

[Means for solving the problem]

Therefore, the present invention is a borehole scanner that illuminates the hole wall through a slit from a moving sonde, moves up and down the hole, extracts light reflected from the hole wall, and observes the hole wall, provided outside the sonde. A light source, a photoelectric conversion means provided outside the sonde, and the light from the light source outside the sonde is transmitted to the slit position to irradiate the omnidirectional hole wall, and the reflected light from the omnidirectional hole wall at the slit position An optical transmission system having an optical fiber for taking in the light and transmitting it to the photoelectric conversion means, a position detection means for detecting the observation position from the direction and position of the sonde, and a process of scanning the signal of the photoelectric conversion means and taking out the image data of the wall surface Data processing means.

[Action]

In the borehole scanner of the present invention, the reflected light from the omnidirectional irradiation hole wall is guided to the photoelectric conversion means by the optical transmission system. Therefore, by disposing the photoelectric conversion means outside the hole, there is no rotation mechanism in the sonde. In addition, since the data processing means scans the signal of the photoelectric conversion means and generates the image data of the taken-out wall surface, high-speed reading can be performed statically. Therefore, hole wall observation can be performed in a short time. Further, by using the optical fiber of the optical transmission system for the transmission of the irradiation light from the light source and the transmission of the reflected light to the photoelectric conversion means, the hole wall can be observed by introducing only the optical fiber into the sonde.

〔Example〕

 Hereinafter, embodiments will be described with reference to the drawings.

1 is a diagram showing one embodiment of a borehole scanner according to the present invention, FIG. 2 is a diagram showing a configuration example of a photoelectric conversion unit, FIG. 3 is a diagram showing a configuration example of a signal processing system, and FIG. It is a figure for explaining a detection angle of a meter and an inclinometer. In the figure,
1 is a sonde, 2 is an optical fiber, 3 is a slit, 4 is a light source, 5 is a photoelectric conversion unit, 6 is a reflected light separation unit, 8 is a compass,
9 is a tachometer, 10 is an inclinometer, 13 is a scanning unit, 14 is a hole bending measurement unit, 15 is an input image control unit, 16 is a CRT, 17 is a data processing device, 18-1 is an external storage device, and 18-2. Indicates an output device.

In FIG. 1, a sonde 1 houses an optical fiber 2 above to obtain an observation image of a hole wall, and houses a hole bending measuring device below to measure the direction and position of the sonde. An observation image of the hole wall is obtained through the portion of the slit 3, and the slit 3 is covered with a transparent member such as glass. The optical fiber 2 is obtained by extending the optical fiber 2 from the ground to the position of the slit 3, directing the tip to the hole wall in all directions (360 °), irradiating the hole wall from the tip, and returning the reflected light. Note that if a transparent member such as glass is used for the slit 3, image disturbance due to light reflection or the like becomes a problem. In such a case, a polarizing glass or the like may be used.

One end of the optical fiber 2 is directed from the slit 3 to the hole wall, while the other side is branched into a light source 4 and a photoelectric conversion unit 5 through a reflected light separation unit 6 as shown in FIG. , Respectively, are directed to the light source 4 and the photoelectric conversion unit 5. Therefore, as shown in FIG. 2A, the optical fiber 2 is configured to transmit the light from the light source 4 and the reflected light from the hole wall between the reflected light separating section 6 and the position of the slit 3 so that the irradiation light and the reflected light are not reflected. From the shared transmission unit, the irradiation light transmission unit that transmits the light from the light source 4 that is branched by the reflected light separation unit 6, and the reflected light transmission unit that transmits the reflected light separated by the reflected light separation unit 6 to the photoelectric conversion unit 5 Become. For example, a semi-transparent mirror or a prism can be used as the reflected light separating unit 6. Light from the light source 4 is transmitted to the slit 3 side through the reflected light separating unit 6 to irradiate the hole wall, and transmitted from the slit 3 side. The reflected light from the hole wall observation is separated by the reflected light separation unit 6 into the photoelectric conversion unit 5. The photoelectric conversion unit 5 includes a large number of photoelectric conversion elements that are linearly arranged. In the ground data processing device, the reference position of the photoelectric conversion unit 5 is scanned while confirming the correspondence with the reference position E of the sonde, and the hole wall is scanned. Captures image data. Therefore, when the probe 1 is raised and lowered, a continuous observation image of the hole wall can be obtained.

As the photoelectric conversion unit 5, for example, a charge-coupled device (CCD) and a commercially available linear CCD array can be used. The photoelectric conversion elements are sequentially read by a scan signal. When capturing image data as color data, filters for the three primary colors of light, R (red), G (green), and B (blue), are built in, as shown in FIG. R, G, and B are repeatedly arranged in series, and FIG.
As shown in FIG. 7, R, G, and B may be arranged in parallel. Since a circuit for reading data from such a photoelectric conversion unit is not the gist of the present invention, a detailed description of the circuit is omitted, but for example, a circuit using a shift register or the like is generally used in an image reading device. The readout circuit of the so-called CCD sensor array can be used.

Next, a configuration example of the signal processing system will be described with reference to FIG.

In FIG. 3, a scanning unit 13 reads a reflected light signal for hole wall observation from the photoelectric conversion unit, and an input image control unit 15 performs data processing of the image signal of the photoelectric conversion unit obtained through the scanning unit 13. It controls the scanning unit 13 and the CRT 16 for monitoring for loading into the device 17 and display on the CRT 16. The data processing device 17 is configured by a personal computer or a dedicated processor, and receives image data from the scanning unit 13 through the input image control unit 15 and processes the image data. Further, the data processing device 17 recognizes the observation position from the direction, position, and depth data of the sound obtained from the hole bending measurement unit 14, so that the data and the observation position are correlated. The external storage device 18-1 stores the image data, and magnetic data, a floppy disk, a magnetic disk, or the like is used.
The image data is printed out, and a printer, a plotter, a hard copy device, or the like is used. The image data and the image position data information may be transmitted to a large computer using a dedicated line or a telephone line, though not shown.

As described above, in the sonde 1 of the present invention shown in FIG. 1, in addition to the above-described configuration of the imaging unit, a hole bending measurement device is further housed. An azimuth meter 8 and an inclinometer 10 are provided for measurement, and a tachometer 9 is provided as a means for measuring the direction of the sound 1. The compass 8 includes first fulcrums A and A 'which are rotatable about a line l which coincides with the axial direction of the sound 1 as shown by a dotted line in FIG.
And a line m orthogonal to the line 1 is attached to the sonde 1 at fulcrums A and A 'via second fulcrums Q and Q' which are rotatable, and the measuring unit is arranged vertically with respect to the ground. It is supported in a state that does not change at all times, has a built-in magnet, and measures the inclination direction angle of the sound 1. Similarly, the inclinometer 10 has a line l
Have fulcrums R, R 'rotatable about
B 'is attached to the sound 1 at B', and the measuring unit rotates around the line l in accordance with the inclination of the sound 1, and incorporates a weight to measure the inclination angle of the sound 1. In addition, the tachometer 9 is provided at the position of the mounting fulcrum A of the compass 8, and measures a direction E which is a reference of the sonde 1.

In a three-dimensional coordinate space composed of x, y, and z shown in FIG. 4, when the x-axis direction is the north-south direction, the y-axis direction is the east-west direction, and the z-axis direction is the critical direction of the earth, The azimuth θ represents the azimuth from the north, and the inclination φ represents the inclination from the horizontal plane. In the sonde shown in FIG. 1, the azimuth θ shown in FIG. The inclination angle φ shown in FIG. 4 is obtained from the inclination angle indicated by the total 10.

That is, the bending of the borehole is measured by the compass 8 and the inclinometer 10, and the direction of the sound is measured by the tachometer 9. In the case of observation by an imaging device, the photoelectric conversion element can know the direction of observation from a position relative to a reference position E set in the sonde. The tachometer 9 measures the orientation of the position E, which is the reference of the sonde, in order to determine the orientation of the imaging portion due to the twist. That is, as described above, the azimuth of the position E serving as the reference of the sonde can be obtained by adding the rotation angle δ measured by the tachometer 9 to the azimuth angle θ measured by the azimuth meter 8.

FIG. 5 is a diagram showing an example of a system configuration of the hole bending measuring device, and FIG. 6 is a diagram for explaining a flow of processing by the hole bending measuring device.

In FIG. 5, a depth gauge 21 is provided in a controller on the ground for controlling the length of the gable CL, and detects the length of the cable CL. The calculation unit 23
When the depth meter 21 detects that the length of the cable CL has reached the unit length, the azimuth angle θ and the inclination angle φ are read from the compass 8 and the inclinometer 10, and the length CLL of the cable CL and the azimuth From the angle θ and the inclination angle φ, the length of the cable CL drawn by each component corresponding to the coordinate space shown in FIG. 4 Δ
x, Δy, and Δz are calculated.

The calculation unit 24 stores Δx, Δy, Δz from the storage unit 25 to the previous time.
Position coordinates X _i , Y _i , Z _i obtained by integrating
Is read out, and the lengths Δx, Δy, Δz calculated by the arithmetic unit 23 are added thereto, and the current position coordinates X of the sonde are calculated.
_{i + 1} , Yi _{+ 1} , and Zi _{+ 1} are calculated.

The storage unit 25 stores the position coordinates X, Y, and Z of the sonde calculated by the calculation unit 24 in time series, and also stores the direction of the corresponding sonde, scan data, and its observation position. Things. FIG. 6 shows a flow of processing until the position coordinates X, Y, and Z of the sonde are stored in the storage unit 25 in time series. Then, the output control unit 27 draws and outputs the trajectory of the sonde from the position coordinates X, Y, and Z stored in the storage unit 25 to, for example, a CRT display or an XY plotter, or outputs the scan data by hard copying. Or something to do. There is an apparatus for hard-copying scan data that has been separately proposed by the present inventors (see Japanese Patent Application Laid-Open No. 61-126292).

FIG. 7 (a) shows an example in which the trajectory of the sonde is drawn by the north-south cross section, and FIG. 7 (b) shows an example in which the trajectory of the sonde is drawn by the east-west cross section. FIG. 7 (c) shows an example of drawing the trajectory of the sonde seen from above in a plan view, and FIG. 7 (d) shows an example of drawing the trajectory of the sonde in three dimensions. is there. Control unit 26
Controls the entire operation including the operation units 23 and 24, the storage unit 25, and the output control unit 27.

It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible. For example, in the above-described embodiment, the transmission optical fiber for transmitting the irradiation light and the optical fiber for transmitting the reflected light are shared.
A transmission optical fiber for irradiation light may be arranged at the center of the bundle of optical fibers for transmission of reflected light, and a hole wall may be irradiated from the center of the axis of the sonde in the slit portion. Instead, an electric wire cable may be arranged, and the light source may be turned on at the center of the axis of the sonde in the slit portion.

The borehole scanner of the present invention can be applied not only to the observation of the wall surface of a borehole, but also to the investigation of various hole walls such as corrosion of a pipeline buried underground.

〔The invention's effect〕

The conventional imaging unit uses a mechanical scan method in which a mirror is rotated by a motor, so replacement of the gear due to wear of gears or deterioration of the motor performance, maintenance such as adjustment is required, but according to the present invention, Since the observation unit is of a stationary type having no movable parts, there is no longer a portion having a high degree of wear as in the related art, so that maintenance work and cost can be greatly reduced. In addition, since no motor is used, noise is reduced and image stability and image quality can be improved. Furthermore, since it is a stationary type and can capture the wall image of one round at the data scanning speed, the wall image can be captured at high speed, and the observation time can be reduced. In addition, since the optical fiber is extended from the ground to the slit and its tip is directed to the omnidirectional hole wall to capture the reflected light, the configuration inside the sonde is simplified. Since the image capturing side can also be arranged facing the linear photoelectric conversion array, there is no need to prepare a specially-shaped photoelectric conversion means in accordance with the hole wall of the observation section, and a commercially available photoelectric conversion array can be used. In addition, a sonde that does not house a light source or a photoelectric conversion unit can be provided by using or sharing a part of the optical fiber for a light source.

[Brief description of the drawings]

1 is a diagram showing one embodiment of a borehole scanner according to the present invention, FIG. 2 is a diagram showing a configuration example of a photoelectric conversion unit, FIG. 3 is a diagram showing a configuration example of a signal processing system, and FIG. FIG. 5 is a diagram for explaining a detection angle of the meter and the inclinometer, FIG. 5 is a diagram showing a configuration example of a hole bending measurement system, FIG. 6 is a diagram for explaining a flow of processing by the hole bending measurement device, FIG. The figure shows an example of a trajectory image obtained by the hole bending measurement device, FIG. 8 shows a specific example of the configuration of a conventionally used borehole scanner, and FIG. 9 shows the hole wall scanned by a light beam. It is a figure showing a locus of a development surface. 1 ... sonde, 2 ... optical fiber, 3 ... slit,
4 light source, 5 photoelectric conversion unit, 6 reflected light separation unit,
8: Compass, 9: Tachometer, 10: Inclinometer, 13: Scanning unit, 14: Bending measurement unit, 15: Input image control unit, 16: CRT, 17: Data processing Device, 18-1 ... external storage device, 18-2 ... output device.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) E21B 47/00

Claims (6)

(57) [Claims] 1. A borehole scanner for irradiating light to a hole wall through a slit from a sonde moving up and down and moving through a hole, taking out reflected light from the hole wall, and observing the hole wall, a light source provided outside the sonde. And photoelectric conversion means provided outside the sonde, transmitting light from the light source outside the sonde to the slit position and irradiating the hole wall in all directions with the reflected light from the hole wall in all directions at the slit position. An optical transmission system having an optical fiber for transmitting to the photoelectric conversion means; a position detection means for detecting an observation position from a direction and a position of a sonde; and a data for generating and processing image data of a wall surface by scanning a signal of the photoelectric conversion means. A borehole scanner comprising: processing means. 2. The optical transmission system according to claim 1, further comprising a separating means for separating the reflected light from the hole wall, and wherein said optical fiber is provided between said separating means and a slit position to reflect light from said light source and reflection from said hole wall. A shared transmission unit for irradiating light and reflected light for transmitting light, an irradiating light transmitting unit for splitting the light from the light source and transmitting the reflected light separated by the separation unit to the photoelectric conversion unit; 2. The borehole scanner according to claim 1, wherein the borehole scanner comprises a reflected light transmitting section. 3. An optical transmission system, comprising: an optical fiber for transmitting irradiation light for transmitting light from the light source to a slit position and irradiating the hole wall in all directions; and reflected light from the hole wall in all directions at the slit position. 2. The borehole scanner according to claim 1, comprising an optical fiber for transmitting reflected light which takes in the light and transmits the reflected light to the photoelectric conversion means. 4. The borehole scanner according to claim 1, wherein the ends of the optical fibers facing the photoelectric conversion means are linearly arranged. 5. The borehole scanner according to claim 1, wherein a polarizing glass is used for the slit. 6. The borehole scanner according to claim 1, wherein the data processing means generates image data in correspondence with the observation position by the position detection means.