JPH10318749A - Position detector and detecting method for underground drilling machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for detecting the drilling position of an underground drilling machine accurately even under a state where a temperature distribution is present in a space being irradiated with a laser beam. SOLUTION: The position detector for underground drilling machine comprises a laser oscillator and a light receiving unit spaced apart therefrom and receiving the laser beam to detect the light receiving position. The position detector detects the drilling position of an underground drilling machine based on the laser beam receiving position detected by the light receiving unit. The laser oscillator 8 comprises a first laser source 80 generating laser beams of different wavelength, a second laser source 81 and a dichroic mirror 82 for combining these laser beams and outputting the combined laser beam 500. The light receiving unit detects the light receiving position of each laser beam having different wavelength and the normal light receiving position of the laser beam is operated when the laser beam propagates straight based on each light receiving position and the refractive index of each laser beam. Finally, the drilling position of the underground drilling machine is detected based on the operation results.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground excavator, such as a pipe propulsion machine or a shield excavator, which excavates underground while forming an underground pit. The present invention relates to a method for detecting the position of an underground excavator that detects the position of an underground excavator, and a device for detecting the position of an underground excavator used directly for implementing such a method.

[0002]

2. Description of the Related Art Drilling underground while forming an underground pit,
Underground excavators such as pipe propulsion machines and shield excavators need to be able to excavate correctly along a planning line that is a preset excavation route. In the underground excavator, as a device for meeting such a demand, a device for detecting the excavation position of the underground excavator using a laser beam has been widely used. The underground excavator position detecting device detects a laser beam receiving position by receiving a laser beam generated by a laser beam generating unit with a laser beam receiving unit installed at an interval from the laser beam. The underground excavator is detected based on the light receiving position. The present invention seeks to improve the reliability of such a conventional underground excavator position detecting device. Therefore, in order to facilitate understanding of the present invention, taking a case where a conventional underground excavator position detecting device is used for a pipe propulsion method as an example, its basic technical contents will be described with reference to FIGS. explain. FIG. 5 is a side view schematically showing a situation when a pipe propulsion method is performed using a conventional underground excavator position detecting device,
FIG. 6 is a side view schematically showing a light receiving device in a conventional underground excavator position detecting device.

[0005] In FIG. 5, reference numeral 1 denotes a starting shaft which is a starting point for burying a pipe, and 2 denotes a starting conductor which is installed in the starting shaft 1 and has a leading conductor 3.
And a propulsion device having a push jack for propelling the buried pipe 4, a cutter 3 for excavating the ground, a leading conductor as a machine for excavating the ground by applying thrust, 4
Is a buried tube such as a fume tube connected to the rear end of the leading conductor 3, 5 is a laser oscillator as a laser beam generating means capable of generating a laser beam, 50 is a laser beam generated by the laser oscillator 5, 6 is a laser beam. Is the laser beam 50
And a light receiving device 7 as a laser beam receiving means configured to detect the light receiving position of the laser beam 50. Reference numeral 7 denotes a reaching shaft which becomes a reaching point of the pipe burial. The tip conductor 3 has a direction correcting function that can correct the direction of the excavation. For example, the leading conductor 3 may be composed of a plurality of trunks that are tiltably connected to each other, and the front trunk may be tilted with respect to the rear trunk by a stroke difference of a plurality of direction correcting jacks. By doing so, the direction of excavation of the leading conductor 3 can be corrected. The tube propulsion device is roughly composed of a propulsion device 2 and a leading conductor 3, and has a direction correcting function.

[0004] The laser oscillator 5 is usually installed in the starting shaft 1, and the light receiving device 6 is usually installed in the leading conductor 3. The laser oscillator 5 is generally installed so as to irradiate a laser beam 50 on a buried planned line which is a planned line. The light receiving device 6 is composed of elements as shown in FIG. The technical content will be described with reference to FIG. 6. Reference numeral 60 denotes a frosted glass target plate that irradiates the laser beam 50 and scatters the light of the laser beam 50, and 61 denotes light of the laser beam 50 scattered by the target plate 60. A focusing lens 62 is a light receiving element such as a CCD for receiving the light collected by the lens 61. The light receiving device 6 is roughly composed of the target plate 60, the lens 61, and the light receiving element 62. The laser beam 50 is applied to the buried pipe 4
Is irradiated on the target plate 60 through the interior of the light receiving element 62.
Are arranged to form an image.

[0005] When the pipe propulsion method shown in FIG. 5 is carried out, the propulsion device 2 installed in the starting shaft 1 first propells the tip conductor 3 and propulses it for a predetermined distance. A buried pipe 4 is installed between the conductor 2 and the leading conductor 3, and then the rear part of the buried pipe 4 (left side in the figure) is propelled. Then, the propulsive force is transmitted to the leading conductor 3 via the buried pipe 4, so that the leading conductor 1 excavates the ground with a cutter head while forming a thrust, thereby forming an underground pit. In the underground pit thus formed, the buried pipe 4 is pushed and buried in the propulsion process by the propulsion device 2. An unillustrated earth discharging pipe is laid in the buried pipe 4, and excavated earth and sand generated in the course of excavating the ground is discharged to the ground through the earth discharging pipe. Thereafter, the installation and propulsion of the buried pipe 4 are sequentially repeated to propel the leading conductor 3 to a predetermined distance, and only the leading conductor 3 is collected by the arrival shaft 7. With the construction using the pipe propulsion method as described above, the buried pipe 4 is connected so as to connect between the starting shaft 1 and the reaching shaft 7.
Is buried.

An underground excavator position detecting device constituted by a laser oscillator 5 and a light receiving device 6 is used during such an operation to detect the position of the leading conductor 3 and based on the detection result, the leading conductor 3 is positioned. 3 is maneuvered so as to be able to excavate correctly along a predetermined burial path, which is a buried route. FIG.
When the leading conductor 3 is positioned on the buried line in the excavation process, the laser beam 50 is irradiated to the reference point O on the target plate 60, When the leading conductor 3 deviates from the planned burying line, it is irradiated to a position shifted from a point O which is a reference point of the target plate 60. This shift amount is detected by the light receiving element 62 on which an image on the target plate 60 is formed. Based on this shift amount, the excavator 3 is laid in the buried line using the direction correcting function of the leading conductor 3. Correct the direction to return to.

Since the leading conductor 3 needs to perform various operations such as driving the cutter head and correcting the direction as described above, an actuator such as a direction correcting jack and a hydraulic motor for driving the cutter is provided inside the leading conductor 3. Is provided. Therefore, inside the buried pipe 4, a hydraulic hose that connects a hydraulic pressure source installed in the starting shaft 1 and their actuators is disposed. Generates heat, and acts as a heating element, causing a temperature change in the internal space of the buried pipe 4. Also,
If the tip conductor 3 is of a type that excavates and discharges earth and sand from the ground, a discharging pipe is laid in the buried pipe 4 as described above. Since heat is generated by friction with the earth and sand, the discharge pipe also acts as a heating element and causes a temperature change in the internal space of the buried pipe 4. As described above, since a temperature change occurs in the buried pipe 4 due to various factors, a region having a temperature different from the center of the heating element in the radial direction of the buried pipe 4 is formed in the inner space of the buried pipe 4. As a result, a so-called temperature distribution is formed.

On the other hand, the laser beam 50 has such a property that the refractive index relatively increases when the temperature of the air becomes relatively high. Therefore, when the above-described temperature distribution is formed in the internal space of the buried pipe 4, a region in which the refractive index of the laser beam 50 is different is formed in the internal space of the buried pipe 4 in accordance with the temperature distribution. A refractive index distribution occurs, and the laser beam 50 is bent toward a higher refractive index. For example, when a heating element such as a hydraulic hose is located at the center of the buried pipe 4 and the laser beam 50 passes through the upper part of the buried pipe 4, the laser beam 50 has a high temperature and a high refractive index. Attracted towards the center of the. Therefore, even when the leading conductor 3 is digging on the buried line, the target plate 60
Is radiated downward, the operator determines from the detection position of the light receiving device 6 that the position of the leading conductor 3 is above the buried line and corrects the direction downward. As a result, unlike the operator's recognition, the leading conductor 3 is not properly steered so that the excavation route is along the planned burial line. Due to such refraction of the laser beam 50, for example, while excavating about 200 m, the excavation position may be displaced by about 10 cm from the planned burial line.

As a technique to avoid such a problem,
Conventionally, for example, JP-A-3-68810 and JP-A-3-260
285 has been proposed.
All of the techniques described in these publications send air from outside into a tubular body such as a buried pipe in which a position detection device that detects a digging position of an underground digging machine based on a light receiving position of a laser beam is installed. In this way, the cylindrical body is cooled to make the temperature inside the cylindrical body uniform.

[0010]

SUMMARY OF THE INVENTION However, the inventor has
Investigations and studies were conducted on the above-mentioned conventional technology for preventing the occurrence of a temperature distribution by introducing air. As a result, such technology cannot completely prevent the occurrence of a temperature distribution. It was found that a displacement of about cm remained. In other words, according to research and research, in the process of discharging air that has come into contact with the heating element by introducing outside air, if the discharged air is in a laminar flow state, it is relatively closer to the side closer to the heating element. If a constant temperature distribution occurs such that a high-temperature airflow and a relatively low-temperature airflow steadily occur on the side far from the heating element, and if the discharged air is in a turbulent state, It has been found that the laser beam sways as it passes through the kerosene. Therefore, in order to accurately detect the excavation position of the underground excavator,
It was concluded that it was necessary to change the conventional idea of trying to prevent a temperature distribution from occurring in the laser beam irradiation space. As described above, the problem of the conventional technology has been described by taking the case where the conventional underground excavator position detecting device is used for the pipe propulsion method as an example, but even when the conventional technology is used for the shield method, the shield jack, the direction correcting jack, the cutter drive The same problem arises as long as a heating element such as a hydraulic hose for supplying and discharging hydraulic oil to a hydraulic motor and the like and a discharging device are provided in the existing segment.

The present invention has been made on the basis of the above-described new findings, and the technical problem of the present invention is to provide an underground excavator even when a temperature distribution exists in a space irradiated with a laser beam. An object of the present invention is to provide a technology for detecting the position of an underground excavator using a laser beam that can accurately detect the excavation position.

[0012]

In order to achieve the technical object of the present invention, the first invention of this application relating to a method of detecting the position of an underground excavator employs the following technical means of 1). The second invention of this application relating to a position detection device for an underground excavator employs the following technical means 2). 1) In a position detection method of an underground excavator for receiving a laser beam at intervals and detecting the excavation position of the underground excavator based on the received position of the received laser beam, a plurality of types of laser beams having different wavelengths are provided. To detect the light receiving positions of these plural types of laser beams, and based on the data on the detected light receiving positions of the plural types of laser beams, the light receiving positions of the laser beams when the laser beams propagate so as to go straight. Is calculated, and the excavation position of the underground excavator is detected based on the calculation result. 2) A laser comprising: a laser beam generating means capable of generating a laser beam; and a laser beam receiving means capable of receiving the laser beam at an interval from the laser beam generating means and detecting a light receiving position of the laser beam. In an underground excavator position detecting device that detects the excavation position of the underground excavator based on the light receiving position of the laser beam detected by the beam receiving unit, as a laser beam generating unit,
A means capable of generating a plurality of types of laser beams having different wavelengths is provided, and the light receiving positions of the plurality of types of laser beams are detected by the laser beam receiving means. The light receiving position of the laser beam when the laser beam propagates so as to travel straight ahead is calculated based on the calculation result, and the excavation position of the underground excavator is detected based on the calculation result.

The first invention of this application is directed to a case where a plurality of types of laser beams having different wavelengths are used and the laser beam propagates so as to travel straight based on data on the light receiving positions of the plurality of types of laser beams. The light receiving position of the laser beam is calculated by calculation, so even if the temperature distribution exists in the space where the laser beam is irradiated, the excavation position of the underground excavator can be accurately determined based on the calculation result. Can be detected. Second of this application
Since the second invention is an invention of a device directly used for carrying out the invention of the first method of the present application, it naturally has the same operation and effect as the first invention of the present application.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments showing how the invention relating to the underground excavator position detecting device of this application is actually embodied will be described below with reference to FIGS. The embodiments of each invention of this application will be clarified. FIG. 1 is a side view schematically showing a laser oscillator in an underground excavator position detecting device according to an embodiment of the present invention;
FIG. 2 is a side view schematically showing a light receiving device and an arithmetic unit in the underground excavator position detecting device according to an embodiment of the present invention.
Is an explanatory view for explaining a basic principle of an underground excavator position detecting device according to an embodiment of the present invention; FIG. 4 is a modification of the underground excavator position detecting device according to an embodiment of the present invention; FIG. 3 is an explanatory diagram for explaining the method. In FIGS. 1 to 4, the portions denoted by the same reference numerals as those in FIGS. 5 and 6 represent the same portions as those in FIGS.

An underground excavator position detecting apparatus according to an embodiment of the present invention comprises a laser oscillator serving as a laser beam generating means, and a laser beam generated by the laser oscillator received at an interval from the laser oscillator. And a light receiving device 6 as a laser beam receiving means capable of detecting the light receiving position of the underground excavator based on the light receiving position of the laser beam detected by the light receiving device 6. In this respect, it is not different from the conventional underground excavator position detecting device described above. In addition, the light receiving device 6 includes a target plate 60 that scatters the light of the laser beam 50, a lens 61 that collects the scattered light, and a light receiving element 62 that receives the collected light. This is no different from the conventional underground excavator position detecting device.

The characteristic technical contents of the underground excavator position detecting device of this embodiment will be described with reference to FIGS. FIG. 1 is a diagram schematically showing components of a laser oscillator 8 in a position detecting device according to the present embodiment. Reference numeral 80 denotes a first laser source for generating a laser beam having a predetermined wavelength, and 81 denotes a first laser source. A second laser source for generating a laser beam having a wavelength different from that of the laser beam from the laser source 80, and a laser beam 82 combines the laser beam from the first laser source 80 and the laser beam from the second laser source 81. A dichroic mirror for The dichroic mirror 82 transmits the laser beam from the first laser source 80 and reflects the laser beam from the second laser source 21 so as to align the emission directions of the two laser beams, that is, to combine the laser beams. do. Thus, the laser oscillator 8 includes the first laser source 80 and the second
, And combines the laser beams of the two laser sources 80 and 81 to emit a combined laser beam 500 as if it were a single beam.

The greatest feature of the present invention is that the laser oscillator 8 emits laser beams having different wavelengths. In the case of emitting laser beams having different wavelengths from the laser oscillator 8, in this embodiment, a plurality of laser sources 8 for generating laser beams having different wavelengths are used.
Although 0 and 81 are provided, for example, one tunable laser capable of selectively switching and generating laser beams having different wavelengths is used, and laser beams having different wavelengths are alternately time-shared in different time zones. The light may be emitted by a ring method. Alternatively, a white laser that oscillates at multiple wavelengths may be used to alternately apply a filter that passes only laser light of each specific wavelength so that laser beams having different wavelengths are extracted at different time zones. In the case of generating laser beams having different wavelengths, in this embodiment, only two types of laser beams having different wavelengths are generated. However, three or more types of laser beams may be generated as described later.

FIG. 2 is a view schematically showing components of the light receiving device 6 used in this embodiment.
A light receiving device 6 including a lens 61 and a light receiving element 62;
In itself, there is essentially no difference from the light receiving device 6 in the conventional example. However, the light receiving element 62 of the light receiving device 6
Since two types of laser beams having different wavelengths are emitted from the laser oscillator 8, the two types of laser beams are received and the light receiving positions of the two types of laser beams are detected. By utilizing the detection result of the light receiving position of each of these laser beams, even when a temperature distribution occurs in the irradiation space of the laser beam, the laser beam is not affected by the temperature distribution. The regular light receiving position can be obtained by calculation by a method described later. In this embodiment, an arithmetic unit 70 is provided to perform such an arithmetic operation, and each detection result of the light receiving element 62 is calculated by the arithmetic unit 7.
0 is input.

The operation of the underground excavator position detecting device of this embodiment will now be described with reference to FIGS.
The mechanism of the arithmetic unit 70 will be described. FIG. 3 shows the target plate 60, and the intersection of the dotted lines crossing in a cross shape so as to form the X and Y axes of the coordinates is the point O as a reference point. That is, when the laser beam 500 propagates so as to travel straight without being affected by the temperature distribution in a case where the leading conductor 3 is located on the line to be buried, the laser beam 500 is radiated to the point O, which is the reference point, and its image is obtained. Is
The light receiving element 62 also forms an image at a reference point. Now, it is assumed that a heating element such as a hydraulic hose or a discharge pipe is arranged at the center of the buried pipe 4, and the inside of the buried pipe 4 is in a state where the temperature is higher toward the center and lower as the surroundings. It is assumed that a laser beam 500 having two wavelengths is emitted from the laser oscillator 8 so as to pass above the heating element. Since the refractive index of the laser in air is relatively large when the wavelength is short, the laser beam 500 having two types of wavelengths emitted from the laser oscillator 8 is propagated in the internal space of the buried tube 4 during the process. A laser beam having a shorter wavelength bends more toward the center, that is, a lower side than a laser beam having a longer wavelength. As a result, as shown in FIG. 3, a long wavelength laser out of the laser beam 500 is applied to the target plate 60.
A laser having a short wavelength is irradiated to a position of Ys far from the point O at a position of Y _L close to the point.

The two types of lasers having different wavelengths and having been irradiated on the target plate 60 are received by the light receiving element 62 in a form reflecting the positional relationship between the irradiation positions Y _L and Ys on the target plate 60 and received by the light receiving element 62. The position is detected.
The light receiving positions for these two types of lasers are processed so as to become the data of the coordinate position in the XY plane coordinates with the origin corresponding to the point O as the origin, and the data is processed by the arithmetic unit 7.
Input to 0. The arithmetic unit 70 moves the laser beam 500 straight without being affected by the temperature distribution in the buried tube 4 based on the data on the light receiving positions of these two types of laser beams and the data on the refractive indexes of the two types of laser beams. The normal irradiation position when the light is propagated is calculated. In the example shown in FIG. 3, for convenience of explanation, an example is shown in which the laser beam 500 is bent only in the Y-axis direction. Therefore, the calculation for obtaining the normal irradiation position is substantially performed in the Y-axis direction. You only have to do it. Laser beam 5
For example, a simple method for calculating the normal irradiation position of 00 may be calculated according to the following equation.

Yo = Y _L- (n _L -1) △ Y / △ n Yo: The normal irradiation position of the laser beam 500 in the Y-axis direction Y _L : The irradiation position of the long-wavelength laser in the Y-axis direction n _L : Refractive index of laser with long wavelength in air ΔY: Difference in irradiation position in the Y-axis direction between two kinds of lasers having different wavelengths Δn: Difference in refractive index of two kinds of lasers having different wavelengths in air Where the refractive index n of the long wavelength laser beam in air
The difference Δn in the refractive index between two types of lasers having different _L and wavelengths in air varies depending on the temperature of the air, and the temperature of the air depends on the surrounding conditions such as the model of the underground excavator and its excavation conditions. An experiment is conducted to determine in advance what temperature should be set to obtain an accurate calculation result, and an appropriate temperature is set based on the experimental result. The above equation does not refract this difference, assuming that the difference ΔY between the irradiation positions of the two kinds of lasers having different wavelengths is caused by the difference Δn in the refractive index of the two kinds of lasers having different wavelengths in the air. This shows a case where addition is performed in proportion to the case. In practice, the laser beam 50
In the process of propagating through the buried pipe 4, the light passing through a portion having a different refractive index depending on the temperature distribution is not linearly refracted but slightly refracted in a curved line. , And a slight error occurs according to the above-described calculation method. To improve the accuracy, the number of lasers having different wavelengths is increased to increase the amount of data on the laser irradiation position, and based on these data, a more accurate calculation for obtaining the proper irradiation position of the laser beam 500 is performed. What is necessary is just to make an expression. that's all,
For convenience of explanation, the laser beam 500 is applied to the target plate 6.
The method of obtaining the normal irradiation position of the laser beam 500 has been described by taking as an example the case where irradiation is performed only in the vertical direction from the reference point of 0. It can be obtained by calculation using the axial component in the same manner as described above.

As described above, based on the data on the light receiving positions of a plurality of types of laser beams having different wavelengths, a theoretical calculation formula is established using the data on the refractive indexes of the plurality of types of laser beams, and the theoretical calculation formula is obtained. According to the method of calculating the laser beam reception position when the laser beam propagates so as to travel straight, that is, the normal irradiation position of the laser beam, based on the data on the light reception positions of such multiple types of laser beams, It is also possible to calculate the normal irradiation position of the laser beam by obtaining an arithmetic expression by an experiment. For example, data on how much the laser beam of each wavelength deviates from the normal irradiation position according to the difference between the light receiving positions of a plurality of types of laser beams having different wavelengths is collected by experiment, and the correlation between the two is examined. By integrating the examination results, a reasonable arithmetic expression for calculating the normal irradiation position of the laser beam may be obtained by experiment.
Thus, the greatest feature of the present invention is based on data on the light receiving positions of a plurality of types of laser beams having different wavelengths,
The point is that the normal irradiation position of the laser beam is calculated, and the calculation method may be appropriately selected in consideration of peripheral conditions.

Next, a modified example of the underground excavator position detecting device of the above-described embodiment will be described with reference to FIG. The lenses have different focal points for different wavelengths of light.
This modification is characterized in that a lens that does not correct such chromatic aberration is used as the lens 61 of the light receiving device 6. FIG. 4 shows an image detected by the light receiving element 62 when such a lens is used as the lens 61. In this example, among the lasers having different wavelengths in the laser beam 500, an image with a longer wavelength forms an image on the light receiving element 62 in focus, and an image with a shorter wavelength forms an image out of focus on the light receiving element 62. You are using such a lens.
As a result, as shown in FIG.
_An image is formed in a state of being well converged at the position of _L , and a laser having a short wavelength forms an image in a state where the spot spreads to the position of Y's and the image is blurred. In this modification, when the light receiving device 6 detects light receiving positions of two types of laser beams having different wavelengths,
As described above, since means for identifying the light receiving positions of the two types of laser beams according to the type of the laser beam is provided, the light receiving positions of the two types of laser beams are set in accordance with the type. The light receiving position of each laser beam can be confused when the calculation device 70 calculates the normal light receiving position of the laser beam 500 using the data on the light receiving positions of the two types of laser beams. It is possible to prevent a calculation error caused by the operation. In this example, an example is shown in which the light receiving positions of the two types of laser beams are identified. However, even when three or more types of laser beams having different wavelengths are used, an image is formed on the light receiving element 62 according to the wavelength length. The same effect can be obtained by adjusting the type of laser beam and the lens so that a difference occurs in the spread of the spot.

As described above, the content of the embodiment of the present invention has been described by taking the case where the underground excavator is a pipe propulsion machine as an example. Naturally, it can also be used to detect the position of another underground excavator that excavates.

[0025]

As is apparent from the above description, the first invention of this application relating to a method of detecting the position of an underground excavator and the second invention of this application relating to a position detection device of an underground excavator are described below. According to these inventions, the temperature distribution exists in the space irradiated with the laser beam, because the technical means described in 1) and 2) of the section "Means for solving the problem" are adopted. A technology for detecting the position of an underground excavator using a laser beam, which can accurately detect the excavation position of the underground excavator even in the state, can be obtained. Second of this application
In the case of embodying the second invention, in particular, if the technical means described in claim 3 is adopted, the light receiving positions of a plurality of types of laser beams can always be correctly detected in accordance with the type of the laser beam, Therefore, when calculating the normal light receiving position of the laser beam using the data on the light receiving positions of a plurality of types of laser beams, it is possible to prevent a calculation error caused by confusing the light receiving positions of the respective laser beams.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing a laser oscillator in an underground excavator position detecting device according to an embodiment of the present invention.

FIG. 2 is a side view schematically showing a light receiving device and an arithmetic unit in the position detecting device of the underground excavator according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram for explaining a basic principle of a position detection device for an underground excavator according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram for explaining a modification of the underground excavator position detecting device according to the embodiment of the present invention;

FIG. 5 is a side view schematically showing a situation when a pipe propulsion method is performed using a conventional underground excavator position detecting device.

FIG. 6 is a side view schematically showing a light receiving device in a conventional underground machine position detecting device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 starting shaft 2 propulsion device 3 tip conductor 4 buried pipe 6 light receiving device 7 reaching shaft 8 laser oscillator 60 target plate 61 lens 62 light receiving element 70 computing device 80 first laser source 81 second laser source 82 dichroic Mirror 500 laser beam

Claims (3)

[Claims] An underground excavator position detecting method for receiving laser beams at intervals and detecting an excavation position of the underground excavator based on a light receiving position of the received laser beam. The laser beam is generated by detecting the light receiving positions of these plural types of laser beams, and based on the detected data on the light receiving positions of the plural types of laser beams, when the laser beam propagates in a straight line. Wherein the light receiving position of the underground excavator is calculated, and the excavation position of the underground excavator is detected based on the calculation result. 2. A laser beam generating means capable of generating a laser beam, and a laser beam receiving means capable of receiving the laser beam at an interval from the laser beam generating means and detecting a light receiving position of the laser beam. In an underground excavator position detecting device that detects a digging position of an underground digging machine based on a laser beam receiving position detected by a laser beam receiving device, a plurality of types of laser beams having different wavelengths are used as a laser beam generating device. A means capable of generating a laser beam is provided, and the laser beam receiving means detects the light receiving positions of the plurality of types of laser beams, and based on the detected data on the light receiving positions of the plurality of types of laser beams, the laser beam is detected. Calculates the light receiving position of the laser beam when propagating straight ahead, and digs underground based on the calculation result An underground excavator position detecting device for detecting the excavation position of an underground excavator. 3. A means for identifying the light receiving positions of a plurality of types of laser beams in accordance with the type of the laser beam when the light receiving positions of a plurality of types of laser beams are detected by the laser beam receiving means. 3. The position detecting device for an underground excavator according to claim 2, wherein: