JPH10300459A - Azimuth measuring apparatus of excavating propulsion machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means for measuring with ease and high accuracy the azimuth of an excavating propulsion machine under the ground. SOLUTION: A horizontally installed first coil C1 and a means (AC voltage 8) for applying an AC voltage to the first coil are provided inside an excavating propulsion machine under the ground, and the azimuth measuring apparatus of the excavating propulsion machine includes at least a second coil C2, which is installed horizontally in such a way as to be substantially perpendicular to the first coil and freely rotate within a horizontal plane, and a means (voltmeter 22) for measuring the induced voltage of the second coil C2 and further includes a means for measuring the rotation angle θ of the second coil C2 and a means for rectilinear regressing the relationship between the rotation angle θand the amplitude of the induced voltage and calculating the angle at which the amplitude of the induced voltage becomes zero on a regression straight line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavation propulsion device which travels horizontally in the ground for burying an optical fiber cable or a sewer pipe, and relates to a technique for measuring an angle (azimuth angle) in a horizontal plane.

[0002]

2. Description of the Related Art Generally, when laying an optical fiber or the like, when the laying position is under a road or the like, traffic is cut off by an "excavation method". Non-cutting method is adopted. For example, FIG.
As shown in FIG. 1, the excavator 1 includes a tip device 3 having a head 2 for direction control, a main pushing device 5 fixed to a shaft, and a number of propulsion pipes 6 connecting the two.
The propulsion pipe 6 is a hollow pipe made of iron, and is pushed into the ground by the main pushing device 5 to form a desired pipe. Prior to the construction, a planning line L indicating the excavation path as the construction target is set on the ground.

In order to propel the excavator 1 along the planning line L, it is necessary to know not only the position of the tip device 3 but also its direction. For example, as shown in FIG. 12, even if only the position of the tip device 3 coincides with the plan line L,
If not parallel to the planning line L, the head 2
It is necessary to control the direction to change the propulsion direction by tilting the planning line L so as to follow the direction in which it is directed.

Conventionally, the "position" and "direction" of the excavator 1 are measured as follows. First, the position in the longitudinal direction along the planning line L is obtained from the extrusion amount of the main pushing device 5. The horizontal position perpendicular to the planning line L is "electromagnetic induction method"
Is measured according to In this electromagnetic induction method, a coil A placed horizontally and at a right angle in the longitudinal direction in the tip device 3 of the excavator 1 shown in FIG. , The coil D placed vertically
This is performed using That is, an alternating magnetic field is generated in the coil A, and the intensity is measured by the coil D. Since the generated magnetic field is horizontal just above the coil A, if the coil D is moved in a direction perpendicular to the planning line L (that is, substantially parallel to the coil A), the generated voltage of the coil D will be right above the coil A. Zero (no induced voltage is generated). Based on this principle, the horizontal position of the tip device 3 can be known. Next, the “depth” of the excavator 1 is obtained by measuring the voltages generated by the coils B and C at a position immediately above the coil A. Generally, the magnetic field generated by the coil A is attenuated with distance, so that the depth of the coil A can be known from the ratio of the voltage generated between the coils B and C. The angle (roll angle and pitch angle) of the excavator 1 in the vertical plane was measured by providing a predetermined inclinometer 9 in the tip device 3 and extracting a signal from the inclinometer 9 to the outside.

[0005]

As described above, the three-dimensional position of the excavator 1 and the two angles in the vertical plane can be directly measured. However, there was no appropriate measurement means for the angle in the horizontal plane (azimuth angle: “yaw angle”). Therefore, conventionally, two horizontal positions obtained by the above-described electromagnetic induction method are connected by a straight line, and the position is estimated from the angle formed by the straight line and the planning line L. However, since the excavator 1 is usually used near a road where traffic is frequent, measuring the position of the tip device 3 from the ground often becomes an obstacle to traffic.
The actual measurement is not performed continuously, but is performed discretely.
For this reason, the estimated yaw angle estimation error is large, and there has been a problem that the position control of the excavator 1 cannot be performed with high accuracy.

As a method of measuring the yaw angle of the excavator 1, a gyro (not shown) is mounted on the tip device 3. However, in this configuration, the device becomes complicated and expensive. Had a problem. For the above reasons,
There has been a demand for a means for measuring the yaw angle of the excavation propulsion machine with high accuracy and ease.

Accordingly, a first object of the present invention is to provide a means for detecting the "yaw angle" of a drilling propulsion device for propelling underground by electromagnetic induction from the ground. A second object is to reduce external noise and increase measurement accuracy.

[0008]

The present invention employs the following means in order to solve the above problems and achieve the object.
That is, the excavation thruster includes a first coil installed horizontally and means for applying an AC voltage to the first coil.
A second coil substantially at right angles to the coil and rotatably installed in a horizontal plane and installed on the ground;
Means for measuring the induced voltage of the coil, means for measuring the rotation angle of the second coil, linear regression of the relationship between the rotation angle and the amplitude of the induced voltage, and the angle at which the induced voltage amplitude becomes zero on the regression line Means for determining

The excavator includes a first coil installed horizontally and a means for applying an AC voltage to the first coil. A second coil substantially at right angles to the one coil and rotatably installed in a horizontal plane and installed on the ground;
Means for measuring the induced voltage of the second coil;
A third coil installed on the ground substantially parallel to the coil, and means for measuring an induced voltage of the third coil;
Means for phase-detecting and averaging the induced voltage of the second coil using the induced voltage of the third coil as a reference signal, means for measuring the rotation angle of the second coil, the rotation angle and the phase detection and averaging Means for linearly regressing the voltage and obtaining an angle at which the phase detection / averaging voltage becomes zero on the regression line.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be schematically described with reference to the accompanying drawings. (First Embodiment) As a first embodiment of the present invention, a first coil C1 horizontally installed in an underground excavator is described.
And means for applying an AC voltage to the first coil (for example, an AC power supply), while the azimuth measuring instrument (yaw measuring instrument) placed on the ground is horizontal and the first A second coil C2 substantially perpendicular to the coil C1 and rotatably installed in a horizontal plane; a means (for example, a voltmeter) for measuring an induced voltage of the second coil; A means for measuring a rotation angle (for example, a goniometer) and a means (for example, a processing circuit) for linearly regressing the relationship between the rotation angle and the amplitude of the induced voltage and obtaining an angle at which the induced voltage amplitude becomes zero on the regression line Is done.

(Function and Effect 1) The following functions and effects are provided by the above-described configuration. However, here, 2 shown in FIG.
In the arrangement relationship between the two coils (C1, C2), the coordinate origin is set to the center of the first coil C1, the vertical direction is set to the z-axis,
The direction of the center axis of the first coil C1 is described as the y-axis, and the direction perpendicular to these directions is described as the x-axis. Also, the first coil C
The horizontal position of the first coil C2 is known by a known electromagnetic induction method and the amount of extrusion of the main pushing device 5 described above.
Is located immediately above the first coil C1.

In this embodiment, first, the first coil C1
, An AC voltage having a constant frequency is applied by an AC power supply 8,
Generate an AC magnetic field. Since the first coil C1 is installed horizontally, the generated magnetic field is generated by the first coil C1.
Directly above (ie, on the z-axis) in the y-direction.

Next, when the second coil C2 is rotated about the z-axis and the induced voltage is measured at various angles θ by the voltmeter 22, the graph of FIG. 2 showing the relationship between the induced voltage and the angle θ is a cosine curve. Draw. However, here, θ = 0 ° when the second coil C2 is parallel to the first coil C1.
And Therefore, it is understood that the direction of the first coil C1 can be detected from the phase angle of the cosine curve.
Further, when the angle is changed by a small amount, the point where the voltage change is the largest is at each of θ = 90 ° and 270 °. That is, if the position where the induced voltage becomes zero is obtained, the direction of the first coil can be known with the highest sensitivity.

However, in an actual construction site, there are various electromagnetic noises, and the induced voltage does not have a perfect cosine curve. On the other hand, when there is no electromagnetic noise, θ = 90 °, 270
In the vicinity of °, the cosine curve can be approximated by a straight line. For this reason, when noise is generated at random, the induced voltage fluctuates evenly near a straight line as shown in the graph of FIG. Therefore, if the induced voltage is regressed by a straight line using the “least square method” in the vicinity of θ = 90 ° or 270 °, a voltage close to the induced voltage containing no noise can be obtained.
If the angle at which the voltage is zero is obtained on the straight line, highly accurate angle measurement can be performed.

(Second Embodiment) As a second embodiment of the present invention, a first coil C1 installed horizontally in an underground excavation propulsion machine, and an AC voltage is applied to the first coil C1. (E.g., an AC power supply).
An azimuth measuring device (yaw angle measuring device) installed on the ground is horizontal and substantially forms a right angle with the first coil C1, and a second coil C2 is installed rotatably in a horizontal plane.
A means (for example, a voltmeter) for measuring an induced voltage of the second coil C2, a third coil C3 installed on the ground substantially in parallel with the first coil C1, and a third coil Means for measuring the induced voltage of C3 (eg voltmeter)
Means for phase-detecting and averaging the induced voltage of the second coil C2 using the induced voltage of the third coil C3 as a reference signal (for example, a processing circuit); and means for measuring the rotation angle of the second coil C2 (E.g., a goniometer), and the rotation angle and the phase detection / averaging voltage are linearly regressed.
Means for obtaining an angle at which the averaged voltage becomes zero (for example, a goniometer).

(Operation and Effect 2) The following operation and effect can be obtained by the above-described configuration. That is, in the configuration of the second embodiment, three coils (C1, C2, C
3) The arrangement is made. In this configuration, the magnetic field generated by the first coil C1 is parallel to the first coil C1 on the z-axis. The induced voltage due to this magnetic field, which can be measured by the voltmeter 22, is that the second coil C2 is the first coil C1.
Is maximum when parallel to and minimum when perpendicular. That is,
Assuming that the electromagnetic noise is isotropic, its relative effect is maximum when the second coil C2 is perpendicular to the first coil C1, and minimum when parallel to the first coil C1. In the first embodiment described above, since the second coil C2 is used at a position substantially perpendicular to the first coil C1, the influence of the electromagnetic noise is maximum.

The configuration of the coil arrangement according to the second embodiment shown in FIG. 4 includes a third coil C3 substantially parallel to the first coil C1. Therefore, in this coil, the effect of electromagnetic noise is minimal. Therefore, the induced voltage of the third coil C3, which can be measured by the voltmeter 23, is used as a reference signal to perform “phase detection” on the induced voltage of the second coil C2 to reduce noise. The “phase detection” is a known signal processing method in which a positive signal is generated when the reference signal has a positive sign, and a negative signal is generated when the reference signal is negative, and the signal is multiplied by the detected signal. When the phase-detected signal is time-averaged, a DC signal having the same frequency as the reference signal and a magnitude proportional to the same phase component is obtained from the detected signal. A signal component having a frequency different from that of the reference signal and a signal component having the same frequency but a phase different by 90 ° are removed. Here, a signal whose phase is different from that of the reference signal by 180 ° is regarded as a signal having the same phase and a negative sign.

The voltages induced in the second and third coils C2 and C3 by the first coil C1 have the same frequency and the same phase. On the other hand, the induced voltage due to the electromagnetic noise has various frequencies and phase components, and the first coil C1
The components having the same frequency and the same phase are extremely small. Therefore, if the induced voltage of the second coil C2 is phase-detected and averaged by using the induced voltage of the third coil C3 having small noise as a reference signal, only the induced voltage due to the magnetic field generated by the first coil C1 can be extracted. Can be. As a result, the present embodiment can further improve the measurement accuracy of the “yaw angle” as compared with the above-described first embodiment.

Next, three examples of an azimuth measuring instrument that specifically implements the gist of the present invention will be described in detail. (First Example) FIG. 5 shows a first example of the first embodiment. As shown in the figure, a fixed base 11 is fixed on a tripod 16, a level 14 is placed on the fixed base 11, and the upper surface is set horizontally by adjusting the leg length of the tripod 16. A rotary table 12 is provided on the fixed table 11 via a rotary axis A, and the rotary table 12 is rotatable about a rotary axis A perpendicular to the upper surface of the fixed table (that is, about a vertical axis). ing. In addition, on the turntable 12,
An encoder 13, a laser oscillator 15, and a coil B are mounted. The laser oscillator 15 has a horizontal rotation axis B
, And is configured to always emit a predetermined laser beam in the same vertical plane as the central axis of the coil B. A coil C is fixed to the lower surface of the fixed base 11, and a down swing 17 is hung vertically downward. Also,
The outputs of the coils B and C and the output of the encoder 13 are connected so as to be supplied to the processing circuit 30. On the other hand, the excavation propulsion device 1 provided with the coil A and the AC power supply 8 is installed underground, and the coil A is set so that the center axis thereof is substantially orthogonal to the propulsion direction of the excavation propulsion device 1 and always keeps horizontal. ing. A planning line L indicating the target of the propulsion route of the excavator 1 is drawn in advance near the ground surface.

The operation principle of this embodiment will be described below. First, an alternating magnetic field is generated from the coil A, and its horizontal position is searched for by a conventional electromagnetic induction method. Next, the tripod 16 is placed on the ground so that the tip of the down swing 17 coincides with the horizontal position of the coil A, the upper surface of the fixed base 11 is horizontal, and the center axis direction of the coil C is substantially perpendicular to the planning line L. Install. Since the propulsion direction of the excavator 1 is substantially parallel to the planning line L, the coils A and C at this time are substantially parallel to each other.

Subsequently, the turntable 12 is rotated, and the encoder 1 is rotated.
3, the voltage generated by the coil B, and the voltage generated by the coil C are input to the processing circuit 30. At this time, the turntable 12
Rotates the coil B by a small amount near a position substantially parallel to the planning line L.

FIG. 6 shows the configuration of the processing circuit 30. In the processing circuit 30, the voltage of the coil B is phase-detected by the phase detection circuit 31 using the voltage of the coil C as a reference signal, and is averaged for a certain time by the averaging circuit 32.
Since the coil C is substantially parallel to the coil A, the signal subjected to the phase detection and averaging processing substantially indicates the component of the magnetic field generated by the coil A in the direction of the coil B. This signal is further digitized by the A / D converter 33,
The regression line operation circuit 34 is input together with the encoder output.

The regression line calculation circuit 34 performs a linear regression on the signal subjected to the phase detection and averaging processing as shown in FIG. (Referred to as “measurement angle”). The measurement angle is displayed on the display unit 35.

Next, the turntable 12 is rotated again, and the angle is set so that the encoder output matches the measurement angle. At this time, the central axis of the laser oscillator 15 is located in the same vertical plane as the coil A. Then, the laser oscillator 15 is operated to irradiate the ground surface with laser light. Normally, the planning line L is shown in FIG.
The vertical angle (pitch angle) of the laser oscillator 15 is adjusted so that the laser beam is irradiated as far as possible on the same straight line as the position of the excavator 1 as shown in FIG. Finally, the distance L1 between the laser beam irradiation point and the planning line,
The distance L2 between the down swing position and the planning line and the distance L3 between the down swing position and the laser beam irradiation point are measured with a tape measure or the like, and the angle φ in FIG. 7 is obtained. This angle φ is an angle formed between the planning line L and the excavator 1 (a direction perpendicular to the coil A). Here, the reason for irradiating the laser light as far as possible is that when the length measurement error due to the tape measure or the like is constant, the accuracy of the angle φ improves as the distance L3 increases.

(Modification 1) In this embodiment, the coil C
However, as shown in the operation and effect of the first embodiment, the yaw angle of the excavator 1 can be measured without using this coil. What is necessary is just to obtain the amplitude of the voltage of the coil B and input the result of the A / D conversion to the regression line calculation circuit 34. As a method of obtaining the amplitude, for example, the voltage of the coil B may be input to the phase detection circuit 31 (FIG. 6) as a reference signal.

(Second Embodiment) FIG. 8 shows a second embodiment of the present invention.
Shown in The features of this embodiment provide a structure simplified from the first embodiment. That is, the laser oscillator is not required, the height of the measuring instrument itself is replaced by bolts without using a tripod, and the rotation axis is close to the surface of the ground and does not require swinging.
Specifically, a turntable 12 is installed on the fixed stand 11 via a rotation axis A, and an encoder 13 and a coil B are fixed to the turntable 12. These rotary table 12 and fixed table 11
Is measured by the encoder 13. A coil C that is substantially perpendicular to the coil B is fixed to the fixed base 11 via a frame 10. Each of the coils B, C and the encoder 13 is connected to the processing circuit 30. The internal configuration of the processing circuit 30 is the same as that of the first embodiment. The fixing stand 11 has three bolts and a level 14
Is attached to adjust the height from the ground,
Is to keep the horizontal. One side surface of the fixing base 11 is a reference surface, and this surface is orthogonal to the center axis of the coil C. The angle of the encoder 13 is set to be zero when the reference plane is parallel to the coil B. Although not shown in FIG. 8, the excavation propulsion machine 1 provided with the coil A is installed underground similarly to the first embodiment.

The operation principle of the second embodiment will be described below. First, an alternating magnetic field is generated from the coil A, and its horizontal position is searched for by a conventional electromagnetic induction method. Next, the rotation axis A
Is fixed to the horizontal position of the coil A and the plan line L is parallel to the reference plane. Subsequently, the turntable 12 is rotated as in the first embodiment, and the encoder 13 is rotated.
, The voltage generated by the coil B and the voltage generated by the coil C are input to the processing circuit 30, and the regression line calculation circuit 34 calculates the measurement angle. This measurement angle is between the planning line L and the excavator 1
And the angle formed by

As described above, in this embodiment, the angle formed between the planning line L and the coil B is obtained by placing the reference plane and the planning line L in parallel. On the other hand, in the first embodiment described above, the angle formed between the planning line L and the coil B by the laser beam is obtained. Therefore, in the second embodiment, the length corresponding to L3 in FIG. 9 becomes the length of the reference plane, and the angle error may be slightly larger than that in the first embodiment. Since no oscillator is required, the structure can be simplified. Further, since it is not necessary to irradiate a distant place with a laser beam, the overall height may be low, and the height of the apparatus is reduced by using bolts instead of a tripod. Further, since the rotation axis A is close to the surface of the ground, the horizontal position of the rotation axis A and the horizontal position of the coil A can be matched without using a down swing.

(Third Embodiment) FIG. 9 shows a third embodiment of the present invention.
(A) and (b) show. This embodiment is a further simplification of the second embodiment. That is, there is no frame for installing the coil C. Specifically, the rotary table 12 includes an encoder 13, a coil B, and a coil C.
Are fixed as shown, and the coil C and the coil B form a right angle. The turntable 1 as in the second embodiment described above.
2, the output of the encoder 13, the voltage generated by the coil B and the voltage generated by the coil C are input to the processing circuit 30, and the measurement angle is obtained by the regression line calculation circuit 34. Therefore, this measurement angle is the angle between the planning line L and the excavator 1.

In this embodiment, the coil C is not safely parallel to the coil A of the excavator (not shown) and rotates by a small angle. However, since the change in the induced voltage in the coil C is a very small amount of the second order of the rotation angle, the change is extremely small and can be regarded as substantially constant. For this reason, the noise reduction effect by the phase detection processing is substantially the same as that of the above-described second embodiment, and the present embodiment further simplifies the structure because a frame is unnecessary as compared with the second embodiment.

(Other Modified Embodiments) The second and third embodiments described above
Also in the embodiment, the yaw angle can be measured without using the coil C as described in the modification of the first embodiment.
While the present invention has been described with reference to a plurality of embodiments and modifications, various modifications can be made without departing from the gist of the present invention.

[0032]

According to the present invention, the yaw angle of the excavator can be measured accurately and easily. In particular,
First, the azimuth angle of the excavator propelling underground (
Yaw angle) can be detected by electromagnetic induction using an azimuth measuring instrument on the ground. Secondly, in measurement, external noise from surroundings such as an operation site can be reduced and measurement accuracy can be increased.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an arrangement of first and second coils and a magnetic action in the present invention.

FIG. 2 is a graph showing an induced voltage amplitude when there is no external noise of a second coil.

FIG. 3 is a graph showing an induced voltage amplitude when external noise is present in a second coil.

FIG. 4 is an explanatory diagram of an arrangement of first and second coils and a magnetic action in the present invention.

FIG. 5 is a schematic diagram showing an excavation propulsion device and a horizontal measuring device according to the first embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a processing circuit of the horizontal measuring device according to the first embodiment;

FIG. 7 is an explanatory diagram illustrating measurement of a laser irradiation angle with respect to a plan line in the first embodiment.

FIG. 8 shows three views of a horizontal measuring instrument according to a second embodiment of the present invention, wherein (a) is a plan view, (b) is a front view,
(C) is a side view.

FIGS. 9A and 9B show a horizontal measuring device according to a third embodiment of the present invention, wherein FIG. 9A is a front view and FIG. 9B is a side view.

FIG. 10 is a schematic view of a conventional excavation propulsion machine and its guiding means.

FIG. 11 is a schematic diagram showing the guiding means of FIG. 10 and a coil in the excavator.

FIG. 12 is a plan view showing directional control of the excavator of FIG. 10;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Excavation propulsion machine, 2 ... Head, 3 ... Tip device, 5 ... Main pushing device, 6 ... Propulsion pipe, 8 ... AC power supply, 9 ... Inclinometer, 10
... Frame, 11 ... Fixed base, 12 ... Turn base, 13 ... Encoder, 14 ... Level, 15 ... Laser oscillator, 16 ... Tripod, 17 ... Down swing, 20 ... Azimuth angle measuring instrument (yaw angle measuring instrument), 22 ... voltmeter of the second coil, 23 ... voltmeter of the third coil, A ... coil A, B ... coil B, C ... coil C, C1 ... first coil, C2 ... second coil, C3 ...
Third coil, 30 processing circuit, 31 phase detection circuit,
32: Averaging circuit, 33: A / D converter, 34: Regression line calculation circuit, 35: Display unit.

Claims (2)

[Claims] A first coil installed horizontally in an underground excavator, and means for applying an alternating voltage to the first coil, wherein the first coil is horizontal and substantially perpendicular to the first coil. A second coil installed on the ground, and rotatably installed in a horizontal plane, and means for measuring an induced voltage of the second coil;
Means for measuring a rotation angle of the second coil, and means for linearly regressing the relationship between the rotation angle and the amplitude of the induced voltage and obtaining an angle at which the induced voltage amplitude becomes zero on the regression line. An azimuth measuring device for a drilling propulsion machine, characterized in that: 2. A first coil installed horizontally in an underground excavator and means for applying an AC voltage to the first coil, wherein the first coil is horizontal and substantially perpendicular to the first coil. And a second coil installed on the ground and rotatably installed in a horizontal plane, and means for measuring an induced voltage of the second coil,
A third coil installed on the ground substantially in parallel with the first coil, means for measuring an induced voltage of the third coil, and a second coil having the induced voltage of the third coil as a reference signal. Means for phase-detecting and averaging the induced voltage of the coil; means for measuring the rotation angle of the second coil; linearly regressing the rotation angle and the phase-detected / averaged voltage; Means for calculating an angle at which the averaged voltage becomes zero.