JP2911101B2 - Underground excavator position detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting the position of an underground excavator (hereinafter sometimes referred to as an excavator), and more particularly to a method of detecting the position of an underground excavator suspended from the ground surface and excavating vertically. And an apparatus.

[0002]

2. Description of the Related Art FIG. 7 shows an example of a conventional method of detecting the position of a down swing type underground excavator. Underground excavator 1 has its top surface 2
Is suspended in the direction of gravity from the ground surface 3 by the suspending wire 5 connected to the ground, and the pit 8 is excavated vertically. In practice, the tip of the excavator 1 may be displaced from the vertical direction due to the hardness of the stratum, and the verticality of the pit 8 may be impaired. In order to ensure the verticality, the position of two points on the excavator 1 is detected, the excavator posture is calculated from those positions, and the required posture or position of the excavator 1 is corrected. . FIG. 7 shows a method for measuring the position of one of the two points, and the same measurement can be performed for the other point. The weight 9 is hung from the reference point 7 on the ground surface 3 by the measurement wire 6 using the template T. In the drawing, R ₁ and R ₂ are wire reels for the suspension wire 5 and the measurement wire 6. Referring to FIGS. 7A and 7B, the suspended weight 9
The sensor tube 40 is fixed at a position on the top surface 2 of the excavator 1 to surround the excavator 1, and two sets of eddy currents for detecting the position of the weight 9 in the coordinate axes XX and YY directions on the excavator 1 Sensor 41
a, 41b and 41c, 41d are provided on the side wall of the sensor tube 40.
If the positions of the two corresponding sensor tubes 40 on the excavator 1 with respect to the two reference points 7 on the ground surface 3 are measured, the attitude of the excavator 1 can be calculated. For example, the calculation is performed by the computer C and the calculation result is obtained. Can be displayed on the display D.

[0003]

However, the conventional method for detecting the position of an underground excavator has the following disadvantages. (1) During excavation, the sensor cylinder 40 or the eddy current sensor 41 may hit the side wall of the vertical hole 8 or the discharged soil and be damaged. (2) It is conceivable to mount the sensor tube 40 inside the frame of the excavator 1 in order to prevent damage. However, in this case, the magnetic field of the eddy current sensor 41 is affected by the surrounding metal and causes a measurement error. Become. (3) Depending on the eddy current sensor 41, accurate measurement is difficult. For example, to accurately measure the position of the weight 9 on the order of 10 cm, the coil of the sensor becomes large, the sensor cylinder 40 also becomes large, and the weight 9 also weighs 100 kg and the height is about 1 m. In addition, it becomes inconvenient to handle.

Accordingly, it is an object of the present invention to provide a small and accurate underground excavator position detecting method and apparatus.

[0005]

With reference to the embodiment of FIG. 1, according to the method of detecting the position of an underground excavator of the present invention, the position of the underground excavator 1 suspended from the ground surface 3 and excavated vertically. In the method of detecting the weight , the sense of the size according to the approach of the weight 9 to a plurality of portions on the excavator 1 whose coordinates on the excavator are known .
Multiple proximity sensing elements 11 that generate response outputs are arranged in a matrix.
Decided and fixed in advance, underground excavator from reference point 7 on surface 3
The weight that is smaller in diameter than the distance between the proximity sensing elements 11 up to just above
The weight 9 is suspended, and one or more proximity sensing elements with respect to the weight 9
The sensing output from the excavator 11 is detected, and the position of the excavator 1 with respect to the ground reference point 7 is detected from the detected sensing output and the coordinates on the excavator of the proximity sensing element 11 that generated the sensing output.

Preferably, the weight 9 is a magnet, and the approach detection element 11 is a Hall element or a magnetoresistive element.

[0007]

The operation of the present invention will be described with reference to the embodiment shown in FIG. In this example, the approach sensing element 11 is a Hall element,
A plurality of approach detection elements 11 are mounted on the position detection unit 20 in a grid-like arrangement, and are fixed to the excavator 1.
Are suspended from the suspension unit 4 provided with the two reference positions 7A and 7B, but the present invention is not limited to this example.

Since the weight 9 suspended from the reference point 7 on the ground surface 3 to just above the underground excavator 1 is vertically below the reference point 7,
The plane coordinates of the reference point 7 on the ground surface are also maintained on the plane coordinates of the weight 9 parallel to the ground surface. For example, a plurality of approach sensing elements 11 are fixed on the excavator 1 in a grid-like arrangement of 5 rows and 5 columns as shown in FIG.
Assuming that the proximity sensing element 11 in the row and the fourth column generates the same output and the outputs of the other proximity sensing elements 11 in the vicinity are symmetric with respect to the row C, the weight 9 is in the same position as the third column on the row C and the third column. It can be detected that it is at the center between the four rows. By the way, since the coordinates of each approach sensing element 11 with respect to the underground excavator 1 are known, C
Based on the fact that the center point between the third and fourth columns on the row is at the plane coordinates of the reference point 7 on the ground, the coordinates of the excavator 1 relative to the reference point 7 and the plane coordinates of the excavator 1 on the ground are accurate. Can be detected.

Even when a plurality of proximity sensing elements 11 are not arranged in a grid, if the coordinates of each proximity sensing element 11 on the excavator and the output of each proximity sensing element 11 are known, the weight is calculated by interpolation. Since the position on the excavator coordinates of the excavator 9 can be detected, the position of the excavator 1 with respect to the reference point 7 can be detected. In addition, the present invention can be formed by, for example, a magnet or a Hall element manufactured at low cost, and does not use a large coil as in an eddy current sensor.

In this manner, the object of the present invention is to provide "a method and apparatus for detecting the position of a small and accurate underground excavator".

[0011]

In the embodiment shown in FIG. 1, two reference points 17 are provided on the top surface 2 of the underground excavator 1 at regular intervals.
Underground excavator 1 whose coordinates on the excavator are known in the vicinity of the excavator
An approach sensing element 11 composed of a Hall element is fixed in a lattice shape to a plurality of upper portions. For convenience of detecting the output of each approach detection element 11, all the approach detection elements 11 may be incorporated into the position detection unit 20 of FIG. As the approach sensing element 11, a magnetoresistive element or another element sensitive to the proximity of the weight can be used instead of the Hall element. The two reference points 7 separated by a fixed distance on the ground surface 7
A and 7B are provided, and the weight 9 is suspended from the reference points 7A and 7B. In the illustrated example, the suspension unit 4 having a hole drilled for penetrating the measurement wire 6 is used, and the reference points 7A and 7B are determined according to the position of the hole. A depth sensor 15 is provided in the measurement wire through hole, and the depth of the weight 9 is detected from the measured value of the extension length of the measurement wire 6. However, the method of detecting the depth of the weight 9 is not limited to the method using the extension length of the measurement wire 6. Sensitive output from one or more proximity sensing elements 11 is detected for each weight 9, and the detected proximity sensing elements are detected.
Each reference point 17 for reference points 7A and 7B from 11 excavator coordinates
The position and orientation of the excavator are measured by detecting the three-dimensional position of the excavator.

FIG. 2 shows an embodiment of a system for detecting the position of the weight 9 from the output distribution of the plurality of proximity sensing elements 11 arranged in a lattice.

Next, an embodiment of the position detecting unit 20 in which the approach sensing elements 11 composed of nine Hall elements are arranged in a cross shape in the C row and the third column of FIG. Consider the case where the magnet 10 of the weight 9 is located between the B and C rows in the second column of FIG. 3B. Since the output of the Hall element is proportional to the magnetic field, it increases as the distance between the magnet 10 and the Hall element decreases, and the output of the Hall element closest to the magnet becomes the largest. 4 (A) shows the position of the weight 9 with magnet in the coordinate system of the rows and columns of FIG. 3 (B), and FIG. 4 (B) plots the output of the approach detection element 11 on the straight line of the third column. FIG. 4C shows a distribution obtained by plotting the output of the approach detection element 11 on a straight line in the C-th row.

FIG. 5 shows a curve obtained by connecting the output values of the approach detection elements shown in FIG. 4B by an interpolation method. Similarly, a curve obtained by connecting the output values of the approach detection elements shown in FIG. 4C by an interpolation method. The principle of measuring the excavator coordinates of the weight 9 as the intersection of straight lines passing through the peak value of the curve and parallel to the rows and columns is shown. By measuring the excavator coordinates of the weight 9, the position of the excavator 1 with respect to the reference point 7 on the ground surface 3 can be detected as described above.

The multiplexer 22 of the position detecting unit 20 shown in FIG. 6 sequentially applies the current I from the control current generating unit 30 to each of the hall elements, that is, the approach sensing element 11, and outputs the output voltage Eh of the approach sensing element 11 to the level sensing unit. Give to 26. In the illustrated example, the voltage amplified by the amplifier 25 is applied to the level detector 26. The multiplexer control unit 32 controls the multiplexer 22
, The connection between the control current I and the output voltage Eh is sequentially switched to each proximity sensing element 11.

The discriminating unit 28 determines the position of the magnet 10 facing the plurality of proximity sensing elements 11 based on the voltage information from the level detection unit 26 and the position information of the proximity sensing element 11 that generated the voltage from the position memory 29. Determine the position. As can be understood from FIG. 5, the position of the magnet 10 and thus the position of the weight 9 can be obtained by proportional distribution based on the voltage from the level detecting section 26.

The computer 34 calculates the known coordinate information of the reference point 7 on the ground surface 3, the excavator coordinate information of the plurality of approach sensing elements 11 on the excavator 1, and the position of the magnet 10 with respect to the approach sensing element 11 from the position detecting unit 20. The ground coordinates of the excavator 1 are calculated based on the position information. The calculation result is provided for display on the display unit 36 or recording by the recording unit 38.

The present inventor has confirmed through experiments that the position of the magnet 10 can be accurately measured with an accuracy of about ± 1 mm using a low-cost Hall element of about several hundred yen.

[0019]

As described above, the method for detecting the position of an underground excavator according to the present invention is capable of positioning the underground excavator in a matrix.
Since a combination of a plurality of approach sensing elements mounted as described above and a weight suspended from the ground reference point and having a diameter smaller than the distance between the approach sensing elements is used, the following remarkable effects are achieved.

(A) It is not necessary to provide a sensor tube in the underground excavator, and it is possible to eliminate the possibility of damage to the position measuring machine parts during excavation. (B) Since an eddy current sensor with a large coil is not used, miniaturization is possible. (C) An underground excavator position detecting device can be manufactured at low cost. (D) The position of an underground excavator can be measured accurately and at low cost with an accuracy of about ± 1 mm. (E) The attitude of the underground excavator can be measured accurately and at low cost.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of one embodiment of the present invention.

FIG. 2 is an explanatory diagram of a lattice arrangement of approach detection elements.

FIG. 3 is an explanatory diagram of a cross-shaped arrangement of approach detection elements.

FIG. 4 is an explanatory diagram of an output of a proximity sensor having a cross-shaped arrangement.

FIG. 5 is an explanatory diagram of weight position detection by an interpolation method of an approach sensing element output.

FIG. 6 is a block diagram of a position detection unit.

FIG. 7 is an explanatory diagram of an example of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Underground excavator 2 Top surface 3 Ground surface 4 Hanging unit 5 Hanging wire 6 Measurement wire 7 Reference point 8 Vertical hole 9 Weight 10 Magnet 11 Approach sensing element 15 Depth sensor 20 Position detecting unit 22 Multiplexer 24 Controller 25 Amplifier 26 Level detection unit 28 Discrimination unit 29 Position memory 30 Control current generation unit 32 Multiplexer control unit 34 Computer 36 Display unit 38 Recording unit 40 Sensor tube 41 Eddy current sensor.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-94463 (JP, A) JP-A-6-258006 (JP, A) JP-A-6-307888 (JP, A) 72291 (JP, A) Fully open 1979-157715 (JP, U) (58) Fields studied (Int. Cl. ⁶ , DB name) G01C 15/00-15/14 E21B 4/00 G01B 7/00 G01D 5/12

Claims (6)

(57) [Claims] 1. A method for detecting the position of the underground excavator to excavate vertically and hung from the surface, a large excavation machine coordinates corresponding to the approach of the weight at multiple sites on a known excavator
Multiple proximity sensing elements that generate sensitivity-sensitive output in a matrix
Pre-positioning and fixing, the underground excavation from the surface of the reference point
The diameter is smaller than the distance between the proximity sensing elements up to just above the machine
Suspending a weight, detecting a sensitive output from the one or more proximity sensing elements with respect to the weight, and detecting the detected output and the coordinates of the proximity sensing element that generated the sensitive output on an excavator to determine the ground surface. A method for detecting the position of an underground excavator, comprising detecting a position of the excavator with respect to a reference point. 2. The position detecting method according to claim 1, further comprising: a depth sensor for detecting a depth of the weight at a reference point on the ground, and detecting a three-dimensional position of the excavator with respect to the ground reference point. Underground excavator position detection method. 3. The position detecting method according to claim 2, wherein two reference points are provided on the excavator at a predetermined interval, and a plurality of reference points on the excavator whose coordinates on the excavator are known near each reference point. The approach sensing elements are positioned and fixed in a matrix at a site, and the weights are respectively suspended from reference positions at two spaced apart from each other on the surface of the ground, and one or more approach sensors for each of the weights are suspended. By detecting the three-dimensional position of each of the reference points with respect to the reference point in each place from the detected output and the coordinates on the excavator of the proximity sensing element that generated the output. An underground excavator position detection method comprising detecting the position and orientation of an excavator. 4. The position detecting method according to claim 1, wherein said approach sensing element is a hall element and said weight is a magnet. 5. The method according to claim 1, wherein the proximity sensing element is a magnetoresistive element, and the weight is a magnet. 6. An apparatus for detecting a position of an underground excavator with respect to a ground reference point, wherein a matrix is provided at a predetermined position on the underground excavator.
Is fixed in the shape of a circle and has a size corresponding to the approach of the weight
A plurality of approach sensing elements that generate a responsive output of the sensor, a suspending unit that suspends a weight having a small diameter from a predetermined position on the ground surface as compared to the distance between the approach sensing elements, to just above the underground excavator, and the weight A position detecting device for an underground excavator, comprising: a position detecting unit that detects a position of the weight with respect to the underground excavator from an output of the approach sensing element responding to the approach of the vehicle and a position of the approach sensing element responding to the approach.