JPH02266211A - Horizontal position measuring instrument for drilling machine - Google Patents

Abstract

PURPOSE:To enable easy, speedy, and accurate detection without carrying a survey instrument to a target point nor performing any complicate traffic interception by laying a magnetic field detection cable on the ground surface and detecting the position. CONSTITUTION:Voltages generated on two magnetic field detection cables 3 and 4 which are laid on the ground surface one over the other along a construction plan line symmetrically about the construction plan line are measured from the magnetic field produced by a magnetic field producing element 1 provided to the drilling head 15 of the drilling machine. Arithmetic is carried out according to the measured voltage to find the deviation of the drilling head 15 from the construction plan line. Thus, the easy, speedy, and accurate detection is performed without carrying the survey instrument to the target position nor performing traffic interception.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for using an excavator to excavate along a construction plan line when burying pipe equipment underground using an excavator without excavating. The present invention relates to a position measuring device for excavating a position.

[Conventional technology] Conventionally, in underground excavation of relatively small diameters for the purpose of burying water pipes and gas pipes, the excavation space is small and curved excavations are frequently performed. First, optical 111ffi using laser transit cannot be applied to measure and confirm this excavation displacement, and it is impossible to accurately measure Sl, especially regarding this horizontal displacement. was the reality. In response to this, recently, a magnetic generation element has been installed inside the underground excavator, and by utilizing the characteristics of the alternating magnetic field generated by this magnetism generating element on the ground surface, it is possible to Four methods have been proposed based on the method of measuring the displacement from a point on the earth's surface, which is published in Japanese Patent Publication No. 11030/1983, titled ``Method for Detecting the Horizontal Stomach of a Thin Shield''.

[Problem to be solved by the invention] Although it is possible to certainly measure the horizontal position of an underground excavator using this method, in practical use, it is necessary to install the above-mentioned magnetic detection element in a predetermined posture. The probe must be transported to the target point on the earth's surface, installed, and explored, resulting in an increase in the number of personnel in charge of measurement, and the labor and time required for measurement.
New problems such as time consuming will arise. Moreover, such a measurement method is almost impossible on roads with a lot of traffic, and if traffic is frequently cut off, the original advantage of the management installation method using underground excavators will be lost.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a device for measuring the horizontal position of an underground excavator, which comprises a magnetic field generating element provided in the excavation head of the excavator, and a magnetic field generating element provided in the excavation head of the excavator. A means for supplying current to the element is placed on the ground surface along the construction plan line, and 9!2 are placed at a constant interval between the outgoing route and the return route to form a loop, and the loop is the construction plan line. The voltages generated in the two sets of cables are measured by the two sets of magnetic field detection cables laid over each other symmetrically with respect to the line, and the magnetic field from the magnetic field generating element. This is a horizontal position measuring device for an excavator that uses calculation to measure the horizontal position deviation of the excavation head from the construction plan line.

[Work] The operation of the above configuration will be explained.

The magnetic field generated by the magnetic field generating element installed in the excavation head of the excavator is used to lay the ground along the construction plan line on the ground surface, and to overlap the construction plan line symmetrically. Measure the voltage generated in the set of magnetic field cables.

By performing calculations based on this measured voltage, the deviation of the excavation head from the construction planning line is determined.

"Example] An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view schematically showing the rough configuration of the apparatus of the embodiment including the excavation head 15 attached to an underground excavator (not shown) in working condition, and FIG. 3 schematically shows a cross section of the device according to the embodiment, and FIG. In these figures, EP is the ground surface, 17
is a starting shaft; 3 and 4 are magnetic field detection cables installed on the ground surface EP; A loop is formed at 23b. Similarly, the magnetic field detection cable 4 forms a loop with the outgoing line 4a and the incoming line 4b, and these magnetic field detection cables 3 and 4 are connected to the construction plan line 1 as shown in FIG.
8, the return line 3b of the magnetic field detection cable 3 and the outward line 4b of the magnetic field detection cable 4 are located at a distance of 1/2L from the center, and the return line 4b of the magnetic field detection cable 4 is oppositely located at a distance of 3/2L. Outbound lines 3a of the magnetic field detection cables 3 are installed parallel to each other at the positions shown in FIG.

On the other hand, there is an excavation head 15 of an excavator (not shown) at the tip of the propulsion pipe 16 excavated along the construction plan line 18.
A magnetic field generating element 1 consisting of a coil is inserted into the digging head 15 at a depth of 1''. A device section 14 is installed on the ground next to the starting shaft 17, and is connected to the magnetic field detection cable 3.4 and the magnetic field generating element 1 by a single cable. The configuration of this device 14 is shown in detail in FIG. That is, as shown in FIG. 4, an oscillator 5 that emits an AC signal having an appropriate repetition frequency.
2 is connected to the magnetic field generating element 1 via a cable 19. The magnetic field generated by the magnetic field generating element 1 is detected by the magnetic field detection cables 3 and 4, and the detection signal is input to the switch 55, and the switched signal, that is, the signal detected by the magnetic field detection cable 3 or the magnetic field detection cable The signal selected as one of the signals detected in step 4 is sent to an amplifier 56, a bandpass filter 57, a detector 58, and an A/D converter 5.
9 and is input to CPtJ60. CPU60 is RO
It is equipped with M61 and RAM62, and is processed according to a program stored in advance in ROM61, and the results are displayed on display 63.

Next, the theory of this embodiment will be explained with reference to FIGS. 5 to 8.

As is clear from FIG. 5, the magnetic field detection cable 3.4 has outward routes 3a, 4a and return route 3b on the ground surface EP.

4b is laid parallel to the construction plan line 18 at intervals of distance, and the outbound path 4a is located at the midpoint of the outbound path 3a and the return path 3b, and the construction plan m18 is located at the midpoint of the outbound path 4a and the return path 3b. . The magnetic field generating element 1 is located at a depth H from the ground surface EP and horizontally separated from the construction plan line 18 by a deviation Δg. In addition, the straight-line distances from the outward paths 3a, 4a and the backward paths 3b, 4b laid on the ground surface to the magnetic field generating element 1 are respectively 13a, J3b, M4a, Jl4.
If it is b, then it becomes.

Next, find the voltage generated in the magnetic field detection cable.

As shown in FIG. 5, the voltage v3a generated in the outgoing path 3a of the magnetic field detection cable 3 is determined by assuming that the angle formed by the vertical axis of the magnetic field generator 1 connecting the outgoing path 3a and the magnetic field generator 1 is 01, and As shown in Fig. 1, when the installation length of the magnetic field detection cables 3 and 4 is LL and this length LL is compared with 413a, if LL>)413a, then V3a = K/''1 3a-cos θ 1
- K# 3a-)-1/j 3a.

Similarly, the voltage V generated on the return path 3b of the magnetic field detection cable 3
Find 3b. In FIG. 5, if the angle between the straight line connecting the return path 3b and the magnetic field generating element 1 and the vertical axis of the magnetic field generating element 1 is 02, and LL>>j 3b, then V3b=/j 3b-cos θ2 = to/# 3b-
H/j 3b.

Since the voltages V3a and V3b found above are in opposite directions, the voltage v3 generated in the magnetic field detection cable 3 is V3 = −H・(1/j) 3a2 −1/J 3b
2) (1a).

On the other hand, the voltage v4 generated in the magnetic field detection cable 4 can be determined in the same manner as the voltage V3 described above. That is,
V4a generated on the outgoing path 4a of the magnetic field detection cable 4 is defined by the angle θ3 between the straight line connecting the outgoing path 4a of the magnetic field detection cable 4 and the magnetic field generating element 1 and the vertical axis of the magnetic field generating element 1.
And if LL >> fJ 4a, then V4a = K/j 4a-cos θ3-/j14a
-H/414a.

Similarly, the voltage V4b generated on the return path 4b of the magnetic field detection cable 4 is determined by assuming that the angle between the straight line connecting the return path 4b of the magnetic field detection cable 4 and the magnetic field generation element 1 and the vertical axis of the magnetic field generation element 1 is 03. , If l l >> J 4b, then V4b = K/j 4b-cos θ3 = /j14b
-H/Jl 4b.

Since the voltages V4a and V4b obtained above are voltages in opposite directions, the voltage v4 generated in the magnetic field detection cable 4 is V4 = K −H・(1,14a −1/j 4b”
)(1b).

Note that K in the above equations (1a) and (1b) is a proportional coefficient that includes the dielectric constant of the earth.

Next, the relationship between the absolute values of the voltages 3 and V4 obtained above and the distance that the magnetic field generating element 1 is horizontally separated from the construction plan line 18, that is, the deviation Δg, is determined by the depth of the magnetic field generating element 1 ("
FIG. 6 shows the results of actual measurements under the condition of H=2L. From this figure, the absolute value voltage ■3 and v4 have a deviation Δg of −L/2≦
It changes almost linearly in the range of Δp≦L/2, and when the proportional constant is k, V3 = is expressed as -ΔN, and V4 = as -Δll.

Therefore, when we apply the above relationship to the situation shown in Figure 5, we get V3=-k(L/2-Δ1) V4-k(L/2+4jl), and the deviation Δ1 is ΔM-(V3+V4) / (V4-V3) -
It is found as L/2. Therefore, the measured voltage V3.
The deviation Δ1 can be determined from V4 and the distance 11L. Note that this deviation Δg is defined as a deviation ρ' as a calculated value. Next, Δp′ of the calculation obtained above is the deviation of the actual measurement Δρ
Figure 7 shows the differences between the two. In Figure 7, the horizontal axis shows the measured deviation Δg, and the vertical axis shows the calculated deviation Δp', H-L.
It is a figure which compared actual measurements under the conditions of -1=31 and H=5L. From FIG. 7, the calculated deviation Δ9' almost matches the measured deviation Δ1. That is, regardless of the depth H of the magnetic field generating element 1, the deviation Δ from the construction plan line 18 is almost exactly
It is possible to find n=.

Therefore, the deviation Δg' can be easily obtained by programming the ROM 11 provided in the device section 14 in advance to obtain the deviation Δg' using the method described above. That is, the value of the installation distance of the magnetic field detection cable is determined in advance by CPtJl.
o, the voltage V3° generated in the magnetic field detection cable 3 is first detected by the switch 55, and this detected value is read by the CPU 60GC via the amplifier 6 or the like. Similarly, the switch 55 is switched to detect the voltage v4° generated in the magnetic field detection cable 4 and read it into the CPU 60.

The CPU 60 uses the read V3', V4° and L to calculate the deviation Δg as ΔJ) - (V3' + V4°) / (V4° - V3°) -
Calculate by L/2.

In addition, ■3 and V4 are expressed by formulas (1a) and (1b), respectively.
What is not necessary is that the formula for calculating the deviation Δρ is v3 and V
This is because the relationship is a ratio of 4, and calculations can be made using relative values.

In this way, in this example, the outbound route and the return route are laid along the construction planned line at a constant interval to form a loop.
The voltage generated in two sets of magnetic field detection cables laid overlapping each other so that the loops are symmetrical with respect to the construction plan line is measured, and the deviation Δ1' is calculated based on the voltage value. The deviation Δp' can be displayed on the display 63.

Furthermore, the excavation direction of the excavation machine can be easily controlled in accordance with this deviation Δ1', and it can be detected automatically and with high sensitivity, and the excavation direction control of the excavation machine can be completely automated. . Furthermore, even if the construction plan line is a free curve, position detection and excavation direction control can be performed in the same way as when it is a straight line.

In addition, in the description of the above embodiment, an example was explained in which the magnetic field detection cable is laid on the ground surface, but the magnetic field detection cable may be laid on the ground surface.

[Effects of the Invention] As described above, in the present invention, a magnetic field detection cable is laid on the ground surface to detect the position.

Therefore, detection can be performed easily, quickly, and accurately without transporting the probe to the target point and without having to block traffic. It can also be applied to curved excavation.

[Brief explanation of drawings]

Fig. 1 is a plan view showing the rough configuration of an embodiment device including an excavation head of an underground excavator according to the present invention, Fig. 2 is a schematic cross-sectional view of the embodiment device, and Fig. 3 is a schematic cross-sectional view of the embodiment device. Fig. 4 is an internal configuration diagram of the device, and Fig. 5 is a diagram showing the magnetic field for explaining the operation of this embodiment. A diagram of the generating element and the magnetic field detection cable viewed from the direction of movement of the excavation head,
Figure 6 shows the relational expression between the deviation Δg and the voltage generated in the magnetic field detection cable, and Figure 7 shows the measured deviation Δg and the calculated deviation Δ1−.
FIG. 1... Magnetic field generating elements 3 (3a, 3b), 4 (4a, 4b) - fjl field calibration detection cable 15 - Niwashin head 17... Starting shaft 18... Construction plan line

Claims (1)

[Claims] A device for measuring the horizontal position of an underground excavator, comprising: a magnetic field generating element provided in the excavation head of the excavator; a means for supplying current to the element; Two sets of magnetic field detection cables are laid at a constant interval on the outbound route and the return route to form a loop, and the cables are laid overlapping each other so that the loops are symmetrical with respect to the construction plan line; An excavator characterized in that the voltage generated in the two sets of cables is measured by the magnetic field from the magnetic field generating element, and the horizontal positional deviation of the excavation head from the construction plan line is measured by calculating the voltage measurement value. Horizontal position measuring device.