JP2757058B2 - Underground excavator relative position detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is suitable for detecting a displacement between two underground excavators that are started facing each other when they are joined underground. The present invention relates to a relative position detection device for an underground excavator.

[Conventional technology]

When constructing a tunnel on the sea floor, it is not possible to install many shafts for starting underground excavators. However, excavating over a long distance with one underground excavator not only causes difficulty in discharging excavated earth and sand, but also involves many dangers. For this reason, when constructing a submarine tunnel, two underground excavators are launched in opposition to each other to shorten the excavation distance of the underground excavator, and tunnels excavated by underground excavators are placed underground. Is performed.

However, if the centers of the two underground excavators are shifted left and right and up and down at the junction, the joined tunnel becomes discontinuous. Therefore, it is necessary to obtain the relative position of the two underground excavators and correct the positional deviation. Conventionally, when correcting the displacement between two underground excavators, the displacement of each underground excavator with respect to the tunnel planning line and the position from a reference position such as a starting point are detected. The relative displacement between the underground excavators was determined, and correction was performed based on the displacement.

Conventionally, the following method has been employed to determine the position of an underground excavator underground.

The position of the underground excavator from the reference point and the deviation from the planned line are determined by underground surveying using transit.

An optical transmission device that generates coherent light such as laser light is installed in the starting shaft of the underground excavator, irradiates the tunnel planning line with this device, and reads the light spot on the target attached to the underground excavator , The position, deviation and declination of the underground excavator from the starting shaft.

The azimuth gyro, pressure squat gauge, inclinometer, and odometer based on the length of the segment assembled in the tunnel are combined to determine the relative position from the reference position.

However, the conventional methods for obtaining the position of the underground excavator described above have the following disadvantages, and it has been difficult to perform underground joining accurately.

The method of (1) requires a large number of measurement points when excavating by bending a tunnel, and cannot be measured in real time, which is impractical. In the method, if the tunnel planning line is bent, the laser beam from the starting shaft may not be able to irradiate the target, and the optical transmitter must be moved to an appropriate position. In addition, since the laser beam cannot be directly irradiated over the entire length of the planning line, each time the optical transmitter is moved, the mutual positional relationship between the target, the optical surveying device, and the tunnel planning line is actually measured, and calculations are performed based on the measurement results. After obtaining the planned route, the position, deviation and declination of the underground excavator must be calculated. For this reason, there is a problem that the transfer, measurement, and calculation of the optical transmission device require labor and the efficiency of the excavation work is reduced.

In addition, the method is also applicable to the case where a cumulative error occurs, it is not suitable for excavation over a long distance, and when excavating a curve with a small radius of curvature, or when excavating a tunnel with a continuous curve Not suitable for And when measuring the relative position of two underground excavators like underground joining,
The error further increases.

On the other hand, as a method of detecting the position of a small underground excavating machine (for example, a mini-mall) at a relatively shallow position in the ground, there is a method of combining an electromagnetic field transmitter / receiver and an inclinometer. This is because the magnetic field generated by the transmitting loop coil installed on the ground surface is detected by the receiving coil provided inside the excavating machine, and the horizontal displacement of the excavating machine with respect to the center of the loop coil is obtained. The position of the excavator in the depth direction is obtained from the value and the excavation distance of the excavator.

However, even in this case, since the position of each of the two underground excavating machines to be joined underground is determined,
When a detection error occurs, the joining cannot be performed accurately.

Therefore, one of the two excavating machines to be joined is provided with a receiving coil for detecting a horizontal position and a receiving coil for detecting a vertical position,
This excavation machine is protruded from the excavating machine by a mini-mall, is brought close to the transmitting coil attached to the cutter face of the other excavating machine serving as a reference position, and the displacement of the receiving coil with respect to the center of the transmitting coil is detected. It is conceivable to detect the relative displacement of the machine.

[Problems to be solved by the invention]

However, the method for determining the relative position of the two excavating machines by providing a transmitting coil on one of the two excavating machines to be joined and a receiving coil on the other of the two excavating machines includes a receiving unit for detecting a vertical displacement, A receiver for detecting a horizontal displacement is required, which makes the apparatus complicated and expensive. In addition, since each receiving unit is constituted by a pair of receiving coils arranged orthogonally, it is necessary to detect the value of the induced electromotive force generated in these coils and obtain the strength of the magnetic field by the transmitting coil.
A detection error occurs depending on the mounting accuracy of the receiving coil, and it is necessary to strictly determine the attitude of the receiving coil.

In addition, since it is necessary to read the value of the detection signal, the magnetic field generated by the transmission coil can only generate a low-frequency magnetic field having a low attenuation in the soil,
It is not easy to increase the receiving sensitivity of the receiving coil.

The present invention has been made in order to solve such a drawback, and it is possible to obtain a relative position of two underground excavators to be joined underground without obtaining a value of a detection signal output from a magnetic field detector. An object of the present invention is to provide a relative position detection device for an underground excavator that can be used.

[Means for solving the problem]

In order to achieve the above object, a position detection device according to the present invention is provided in a magnetic field generator provided in front of one underground excavator to be joined underground, and provided in the one underground excavator, A rotating device for rotating the magnetic field generator in a plane perpendicular to the axis of the underground excavator, and the other underground excavator to be joined underground non-linearly disposed, the magnetic field generated by the magnetic field generator Three or more magnetic field detectors for detection, a propulsion device provided on the other underground excavator, and bringing each magnetic field detector close to the one underground excavator; and a detection signal of each of the magnetic field detectors. A peak detection circuit for detecting a peak, a peak generation time difference measurement circuit for obtaining a peak interval between output signals of the magnetic field detectors based on an output signal of the peak detection circuit, and a peak generation time difference measurement circuit based on an output of the peak generation time difference measurement circuit. To determine the relative position between It is characterized by having a Mel position calculation circuit.

[Action]

According to the present invention configured as described above, when the magnetic field generator is rotated by the rotating device, the detection signal of each magnetic field detector changes periodically. Therefore, the peak of the detection signal of each magnetic field detector is detected by the peak detection circuit, the time interval at which the peak of the detection signal between the magnetic field detectors appears is obtained by the peak occurrence time difference measurement circuit, and is input to the position calculation circuit. The position calculation circuit calculates the angle between the respective magnetic field detectors as viewed from the center of the underground excavator equipped with the magnetic field generator from the time interval obtained by the peak occurrence time difference measurement circuit, and the underground excavator to be joined underground. Find the relative position between

Therefore, in the present invention, it is only necessary to detect that the magnetic field generator has passed in front of or near the magnetic field detector,
When the magnetic field detector is composed of coils, the change in the magnetic field can be easily detected with a single coil, and the device is inexpensive, and it is not necessary to obtain the value of the detection signal itself. There is no need, and errors hardly occur. In addition, since it is sufficient to detect a change in the magnetic field, the influence of attenuation in the soil is small, the frequency of the magnetic field generated by the magnetic field generator can be increased, the detection sensitivity of the magnetic field detector can be increased, and the magnetic field detector can be used. It is possible to detect the relative positions of the two underground excavators even if they are away from the magnetic field generator.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a position shift detecting device according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a configuration diagram of an apparatus for detecting a relative position of an underground excavator according to an embodiment of the present invention.

In FIG. 1, the underground excavators 10 and 20 have cutter drums 12 and 22 each having a cutter (not shown). The cutter drums 12 and 22 are rotatable and can be stopped at an arbitrary rotation position. Also,
The underground excavators 10 and 20 advance while rotating the cutter drums 12 and 22, thereby taking in the earth and sand excavated by the cutter into the cutter drums 12 and 22, and transferring the soil backward by a screw conveyor or the like. I have. These underground excavators 10 and 20 excavate from different starting shafts in directions approaching each other along the tunnel planning line, and join the excavated tunnels.

One underground excavator 10 has a magnetic field generator 14 attached to the front or inside of a cutter drum 12. The magnetic field generator 14 is connected to an AC current source 16 and is supplied with power from the AC current source 16 to generate an AC magnetic field. Also, the magnetic field generator 14
As shown in FIG. 2, the center O of the underground excavator 10 is constituted by a rectangular transmission loop cable, and the cutter drum 12 serving as a rotating device of the magnetic field generator 14 is rotated. Cutter drum 12 around arrow ₁₀ as indicated by arrow 18
And rotate together. Then, the magnetic field generator 14, when the cutter drum 12 is stopped at the reference position, with the long side of the transmission loop cable is parallel to the Z axis is the vertical axis of the underground excavator 10, above the center O ₁₀ And the center of the transmission loop cable is located on the Z-axis.

The other underground excavator 20 is provided with compacting and excavating small-diameter boring devices 24a, 24b, 24c at the front. Detection coils 26a, 26b, and 26c, which are magnetic field detectors, are attached to the tips of the boring devices 24a, 24b, and 24c (see FIG. 3), and the magnetic field generated by the magnetic field generator 14 is detected. I can do it.

The boring devices 24a, 24b, 24c are arranged on a circumference of a radius r centered on the center O ₂₀ of the underground excavator _{20 with} respect to the center O ₂₀ .
Yes and disposed at 120 degree intervals, are located on the vertical axis boring device 24a passes through the center O ₂₀ of the underground excavator 20 (Z-axis). The boring devices 24a, 24b, and 24c are provided on the rear side of the cutter drum 22, and when the cutter drum 22 stops at the reference position, excavate underground through a not-shown through hole formed in the cutter drum 22. It can move back and forth in parallel with the axis (X axis) of the machine 20, and the detection coils 26a, 26b,
It serves as a propulsion device that brings the 26c close to the front of the underground excavator 10.

Each detection coil 26a, 26b, 26c is connected to a preamplifier 2
The detection signals are connected to the amplifiers 30a, 30b, and 30c via 8a, 28b, and 28c (the preamplifiers 28b and 28c are not shown), and the detection signal is amplified by the preamplifier and the amplifier.

The output side of the amplifiers 30a, 30b, 30c has a peak detection circuit 3
2a, 32b, 32c are connected, and the detection coils 26a, 26b, 26
The peak of the output signal c is detected, and when the peak is detected, the peak detection signal is input to the peak occurrence time difference measurement circuit 34. Then, the peak occurrence time difference measuring circuit obtains a time difference between the peak detection signals based on the input time of the peak detection signals from the peak detection circuits 32a, 32b, and 32c, and sends the time difference to the position calculation circuit.

The position calculation circuit 36 includes a boring device as described later.
24a, 24b, 24c excavation amount and peak occurrence time difference measurement circuit 34
And an output of the portions to determine the relative distance between the underground excavator 10 and 20, underground excavator 1 with respect to the center O ₁₀ of the underground excavator 10
It calculates the positional shift of the center O ₂₀ 0, and displays the output to the display device 38.

The operation of the embodiment configured as described above is as follows.

The cutter drum 22 of the underground excavator 10 is stopped at the reference position, and the boring devices 24a, 24b, and 24c are advanced toward the underground excavator 10, and the tip of each boring device is connected to the underground excavator 10.
To the front of the Then, each boring device 24a, 2
The excavation distances of 4b and 24c are input to the position calculation circuit 36. The fact that the tip of the boring device has reached the underground excavator 10 can be easily detected by detecting the excavation resistance of the boring device 24 or the like.

The tip of the boring equipment 24a, 24b, 24c is an underground excavator 10
Of the underground excavator 10
12 is rotated with a predetermined rotation period T as indicated by an arrow 19 in FIG. When the cutter drum 12 rotates, the underground excavator
A magnetic field generator 14 provided in 10 rotates integrally with the cutter drum 12, and sequentially passes in front of detection coils 26a, 26b, 26c provided inside the boring devices 24a, 24b, 24c. And
Each detection coil 26a, 26b, 26c outputs a voltage induced by the magnetic field generated by the magnetic field generator 14 as a detection signal.

The detection signals output from the detection coils 26a, 26b, and 26c are preamplifiers 28a, 28b, and 28c, and amplifiers 30a, 30b, and 3 respectively.
It is amplified by 0c and sent to the peak detection circuits 32a, 32b, 32c. The peak detection circuits 32a, 32b, and 32c take in the values of the detection signals input from the corresponding amplifiers 30a, 30b, and 30c at predetermined time intervals, for example, every 10 ms, and sequentially compare the values. That is, the peak detection circuit 32a includes the amplifier 30a
Captures the detected signal of the detection coil 26a amplified at predetermined intervals, compares the level of the currently captured detection signal with the level of the previously captured detection signal, and detects the peak of the detection signal.

When each of the peak detection circuits 32a, 32b, and 32c detects the peak of the detection signal output from the corresponding detection coil 26a, 26b, and 26c, it sends the peak detection signal to the peak occurrence time difference measurement circuit 34. When the peak detection signal is input from each of the peak detection circuits 32a, 32b, and 32c, the peak occurrence time difference measurement circuit 34 inputs the time at which the peak detection signal is input from the peak detection circuit 32a and the time at which the peak detection signal is input from the peak detection circuit 32b. The difference from the time and the time between the time input from the peak detection circuit 32a and the time input from the peak detection circuit 32c are obtained and input to the position calculation circuit.

The position calculation circuit 36 calculates the relative distance between the underground excavator 10 and the underground excavator 20 from the excavation amount of the boring devices 24a, 24b, 24c, and calculates the relative distance between the boring devices 24a, 24b, 24c. The inclination angle and the inclination direction of the underground excavator 20 with respect to the underground excavator 10 are calculated. In addition, the position calculation circuit 36
From the difference between the time when the center of the magnetic field generator 14 has passed the Z axis and the time when the magnetic field generator 14 has passed the detection coil 26a,
The rolling angle of the underground excavator 20 with respect to the underground excavator 10 is determined. Further, the position calculation circuit 36 calculates the difference (time difference) between the obtained rolling angle and the peak time of the detection signal (output voltage) between the detection coils 26a, 26b, and 26c output by the peak occurrence time difference measurement circuit 34. ), The relative position between the underground excavator 10 and the underground excavator 20, that is, the center O of the underground excavator 10
The position of the center O ₂₀ of the underground excavator 20 with respect to ₁₀ is determined.

As shown in FIG. 4, when the center O ₂₀ of the center O ₁₀ and underground excavator 20 of the underground excavator 10 are coincident, the magnetic field generator 14 rotates with a period T, each Detection coil 26
a, 26b, because 26c is are arranged at intervals of 120 degrees with respect to the center O _20, peak interval of the detection coil 26a, the detection signal between 26b is, T / 3 becomes as shown in FIG. 5, the detection Coil 26a,
The peak interval of the detection signal between 26c is 2T / 3. Therefore,
When the peak interval of the detection signal obtained by the peak occurrence time difference measurement circuit 34 is as shown in FIG. 5, the position calculation circuit 36 indicates to the display device 38 that there is no displacement between the underground excavators 10 and 20. To be displayed.

On the other hand, as shown in FIG. 6, when there is a displacement between the underground excavator 10 and the underground
The peak interval between the detection signals between 26a and 26b is _Tab , and the peak interval between the detection coils 26a and 26c is _Tac (see FIG. 7).

Now, the center O ₁₀ of the underground excavator 10 when the origin of the Y-Z coordinates, the boring device 24a provided in the ground excavator 20
~24c it is assumed that position as Figure 8 with respect to the origin O _10. And, the boring devices 24a to 24c
Are arranged at intervals of 120 degrees with respect to the center O _{20 of} , and are located at the vertices of an equilateral triangle having a side length of l. Therefore, the position calculation circuit 36 determines the rotation period T of the magnetic field generator 14 and the peak interval.
T _ab, and a T _ac, boring device as viewed from the origin O ₁₀ 24a, 24
b (detection coil 25a, 26b) angle θ _ab , boring device
The angle θ _ac between 24a and 24c (detection coils 26a and 26c) is obtained as follows.

On the other hand, the coordinates of each boring device 24a, 24b, 24c are (a _y ,
a _z ), (b _y , b _z ), (c _y , c _z ), and the angle formed by the line connecting the origin O ₁₀ and the boring device 24 c with the Y axis is ψ.
The following equations (5) to (11) are obtained from the geometric relationship.

_{b z = c z ...... (8} ) c y -b y = l ...... (9) a y = (b y + c y) / 2 ...... (10) Since l is known, and θ _ac and θ _ab are obtained by equations (3) and (4), the unknowns are ψ, a _y , a _z , b _y , b _z ,
There are seven of c _y and c _z . Therefore, each unknown can be solved by equations (5) to (11).

From equations (5), (10) and (11) From equations (12) and (9) From equations (13) and (6) On the other hand, from equations (7), (8), and (9), Transforming equation (15) Substituting equation (16) into (14) and rearranging Since only ψ is unknown in equation (17), it can be obtained by successive approximation using a computer.

Further, the formula (16), b _y using (6), b _z, equation (9), a _y by using the c _y with (8), c _z, equation (10), (11), _az can be obtained sequentially.

Therefore, the coordinates P (P _y , P _z ) of the center O ₂₀ of the underground excavator 10 which is the center of the triangle made up of three mini-malls
Is P _y = a _y …… (18) And the relative positions of the underground excavators 10 and 20 can be obtained.

Thus, in the embodiment, the detection coils 26a, 26
The relative positions of the underground excavators 10 and 20 can be obtained only by detecting the peaks of the output signals b and 26c and knowing the time when the peaks occurred. Therefore, in order to detect the strength of the magnetic field generated by the magnetic field generator 14, there is no need to arrange the coils orthogonally, and the magnetic field detector can be constituted by a single coil, and the device becomes inexpensive, Since it is not necessary to determine the absolute value of the detection signal, it is not necessary to strictly determine the attitude of the coil. Moreover, a detector for detecting the positional deviation in the Z axis direction with respect to the center O _10, there is no need to separately provide a detector for detecting the positional deviation in the Y-axis direction, device simple, inexpensive Becomes Also, it is only necessary to detect a change in the magnetic field, and since the influence of attenuation in the soil is small, the frequency of the magnetic field generated by the magnetic field generator can be increased, the detection sensitivity of the magnetic field detector can be increased, and the magnetic field detector can be used. It is possible to detect the relative positions of the two underground excavators even if they are away from the magnetic field generator.

In the above-described embodiment, the case where the magnetic field generator 14 is located in one radial direction from the center of the underground excavator 10 has been described.However, the magnetic field generator 14 has a length substantially equal to the diameter of the underground excavator beyond the center. Or a plurality of them may be provided. In the above embodiment, the case where the magnetic field generator 14 is a transmission loop cable has been described, but the magnetic field generator 14 may be a permanent magnet or the like.

Further, in the above embodiment, the case where the number of the detection coils as the magnetic field detector is three has been described, but the number of the detection coils may be four or more. If three or more detection coils are arranged so as not to be aligned on a straight line, it is not necessary to arrange them on a circumference centered on the center of the underground excavator 20. Further, in the above embodiment, the detection coils 26a, 2a
6b, has been described as being arranged at equal angular intervals of 120 degrees with respect to the center O ₂₀ to 26c, it may not be equal angular intervals. The magnetic field detector is not limited to a coil, but may be any as long as it can detect a magnetic field such as a magnetoresistive element. Further, in the above embodiment, the detection coils 26a, 26b, 26c
A case has been described in which a consolidation drilling type boring device is used as a propulsion device for moving the propulsion, but the propulsion device is not limited to this.

〔The invention's effect〕

As described above, according to the present invention, two underground excavators to be joined underground by detecting peaks of detection signals of three or more magnetic field detectors and determining a time between the peaks An inexpensive device can be obtained because the relative position between them can be obtained and the value of the detection signal itself need not be detected.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a relative position detecting device of an underground excavator according to an embodiment of the present invention. FIG. 2 is a front view of a magnetic field generator provided on the underground excavator while being joined underground. FIG. 4 is a front view showing an arrangement state of a magnetic field detector provided in the other underground excavator to be joined underground. FIG. 4 is an explanatory view of a displacement detection method when the center of each underground excavator is coincident. FIG. 5 is a diagram showing the peak interval of the detection signal when the centers of all the excavators in each region are coincident, FIG. 6 is a conceptual diagram showing a state in which the excavators in each region are displaced, and FIG. The figure shows the peak interval of the detection signal when the center of each underground excavator is shifted, and FIG. 8 is an explanatory diagram of how to determine the relative positions of two underground excavators. 10, 20: Underground excavator, 12: Rotating device (cutter drum), 14: Magnetic field generator, 24a to 24c ... Propulsion device (boring device), 26a to 26c: Magnetic field detector (detection coil) ),
32a to 32c: peak detection circuit, 34: peak occurrence time difference measurement circuit, 36: position calculation circuit.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yasuo Kanemitsu 1200 Manda, Hiratsuka-shi, Kanagawa Examiner at the Komatsu Manufacturing Laboratory Co., Ltd. Yoko Watanabe (56) References JP-A-62-168013 (JP, A) JP-A-62 −106313 (JP, A)

Claims (1)

(57) [Claims] 1. A magnetic field generator provided in front of one underground excavator to be joined underground, and a magnetic field generator provided in said one underground excavator, wherein the magnetic field generator is orthogonal to an axis of the underground excavator. A rotating device that rotates in a plane, three or more magnetic field detectors that are non-linearly arranged on the other underground excavator to be joined underground, and that detect a magnetic field generated by the magnetic field generator; A propulsion device provided in the underground excavator, and bringing each magnetic field detector close to the one underground excavator; a peak detection circuit for detecting a peak of a detection signal of each of the magnetic field detectors; and a peak detection circuit. A peak occurrence time difference measuring circuit for finding a peak interval of the output signal of each of the magnetic field detectors based on the output signal of the respective magnetic field detectors; and a relative position between the excavators in each place based on an output of the peak occurrence time difference measuring circuit. And a position calculation circuit. Relative position detection device of the middle excavator.