JPH042883B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a position detection method and a position detection device using a laser beam.

[Prior Art] FIG. 1 is an explanatory diagram showing a state in which a conventional position detection method is used in a tunnel boring machine or the like.

In the figure, 1 is a laser beam emitting device installed at a fixed position in the starting shaft or tunnel, 2 is the laser beam emitted from the laser beam emitting device 1, and 3 is a light receiving device installed in the tunnel boring machine. An x-axis, y-axis origin O is attached to the light-receiving surface 4 of No. 3.

Next, a conventional position detection method using the above-mentioned position detection device will be explained. A laser beam 2 is emitted from a laser beam emitting device 1 toward a light receiving surface 4 of a light receiving device 3. The point P where the laser beam 2 hits the light receiving surface 4 is read as x, y coordinates. Based on the x and y coordinates read, the laser beam 2
The relative position of the light receiving device 3 with respect to the light receiving device 3 is detected.
As a result, the tunnel excavating machine can be caused to excavate along the planned planned line.

However, in the conventional position detection method, the position is detected by applying the laser beam 2 from the laser beam emitting device 1 to the light receiving surface 4 of the light receiving device 3. Therefore, the position detection range is limited to the light receiving surface 4.
It is limited to the area of For example, if the amount of positional deviation of the tunnel boring machine increases, the laser beam 2
If the intersection point P with the light-receiving surface 4 is removed from the light-receiving surface 4, detection becomes impossible thereafter. For this,
There is a problem in that the light receiving surface 4 must be made as large as possible.

[Purpose of the invention]

The present invention aims to provide a position detection method and a position detection device that solve the above-mentioned problems.

[Structure of the invention]

The invention recited in claim 1 (hereinafter simply referred to as the first invention) emits a band-shaped laser beam from a laser beam emitting device to a light-receiving surface of a light-receiving device, and emits the band-shaped laser beam. rotate the direction as an axis and read at least two straight lines among the straight lines of the band-shaped laser beam appearing on the light receiving surface;
The intersection point of the plurality of straight lines thus read is determined, and the relative position of the light receiving device with respect to the optical axis position of the band-shaped laser beam emitted from the laser beam emitting device is detected from the determined intersection point. shall be.

Further, the invention described in claim 2 (hereinafter simply referred to as the second invention) is configured to emit a band-shaped laser beam and rotate the band-shaped laser beam around the emission direction. a laser beam emitting device, a light receiving device having a light receiving element on its light receiving surface, and at least two of the straight lines of a band-shaped laser beam connected to the light receiving element and crossing over the light receiving element.
an arithmetic device that reads straight lines and determines the intersections of the plurality of straight lines read, and the light receiving device determines the optical axis position of the band-shaped laser beam emitted from the laser beam emitting device based on the intersections found by the arithmetic device. It is characterized by detecting the relative position of devices.

〔Example〕

An embodiment of the first invention will be described below with reference to FIGS. 2 to 6.
Referring to the figure, one embodiment of the second invention will be explained in the seventh embodiment.
Each will be explained with reference to FIGS. 11 to 11.

Figure 2 is an explanatory diagram showing the state in which it is used in a tunnel excavator, etc. Figure 3 is an explanation of the light receiving surface when the optical axis is within the light receiving surface, and Figure 4 is an explanation of the light receiving surface when the optical axis is outside the light receiving surface. Fig. 5 is an explanatory diagram of the light-receiving surface showing the case in which the straight line of the band-shaped laser beam appearing on the light-receiving surface is read from a point on the outermost circumference of the light-receiving surface;
The figure is an explanatory diagram for reading a straight line of a band-shaped laser beam appearing on the light receiving surface from a point inside the light receiving surface.

In the figure, 1' is a laser beam emitting device installed at a fixed position in the starting shaft or tunnel, and this laser beam emitting device 1' emits a band-shaped laser beam 2'. The laser beam 2' is rotated around the emission direction of the laser beam 2'. This laser beam emitting device 1' uses, for example, a light beam type scraping device. 3 is a light receiving device, and 4 is a light receiving surface of the light receiving device 3, which is a scale plate having an origin O on the x and y axes.

Next, a position detection method according to the first invention using the above-mentioned position detection device will be explained.

First, a belt-shaped laser beam 2' is emitted from a laser beam emitting device 1', and the belt-shaped laser beam 2' is rotated. This rotation may be intermittent or continuous. When this belt-shaped laser beam 2' hits the light-receiving surface 4, the light-receiving surface 4
A straight line of light appears above. Furthermore, since the band-shaped laser beam 2' is rotating, the above-mentioned straight line appears on the light receiving surface 4 at any rotation angle. Let this straight line be A. Furthermore, B is a straight line when the belt-shaped laser beam 2' is rotated. The intersection point P between straight line A and straight line B is determined. This intersection P is the optical axis of the band-shaped laser beam 2', and the light receiving surface 4
The difference from the origin O corresponds to the amount of deviation of the tunnel boring machine.

The above-mentioned intersection (optical axis of band-shaped laser beam 2')
If P is within the range of the light-receiving surface 4 as shown in FIG. 3, the position can be detected by the conventional position detection method. However, if the above-mentioned intersection point P is outside the range of the light-receiving surface 4 as shown in FIG.
Position detection is possible by the position detection method of the invention. That is, in the position detection method of the first invention, since the belt-shaped laser beam 2' is rotated, the line-of-sight is clear and the belt-shaped laser beam 2' is rotated.
As long as the laser beam 2' is not blocked, a straight line of the band-shaped laser beam 2' will eventually appear on the light receiving surface 4. This light receiving surface 4
By reading two straight lines A and B among the straight lines appearing above, the intersection point P of the two straight lines A and B can be determined as follows.

In FIG. 5, A and B are straight lines of the band-shaped laser beam 2' appearing on the light-receiving surface 4 at times t _a and t _b .
These straight lines A and B are respectively points A ₁ , A ₂ and
It intersects the outer periphery C of the light receiving surface 4 at B ₁ and B ₂ . This point
Coordinate axes x-y of light receiving surface 4 of A ₁ , A ₂ and B ₁ , B ₂
Let the coordinates related to this be A ₁ (x ₁₁ y ₁₁ ), A ₂ (x ₁₂ y ₁₂ ), B ₁ (x ₂₁ y ₂₁ ), and B ₂ (x ₂₂ y ₂₂ ). Then, the equations of straight lines A and B are as follows:
Determined by (1).

The coordinates of the intersection point P of these two straight lines are P(x ₂₁ y ₂₂ −x ₂₂ y ₂₁ /x ₂₁ −x ₂₂ −x 11 y ₁₂ −x _{12 y 11 /} x _1
1 −x ₁₂ ／y ₁₁ −y ₁₂ ／x ₁₁ −x ₁₂ −y ₂₁ −y ₂₂ ／x ₂₁ −x ₂₂ ，x _1
1 y ₁₂ −x ₁₂ y ₁₁ /y ₁₁ −y ₁₂ −x ₂₁ y ₂₂ −x ₂₂ y ₂₂ /y ₂₁ −y ₂₂ /
x ₁₁ −x ₁₂ /y ₁₁ −y ₁₂ −x ₂₁ −x ₂₂ /y ₂₁ −y ₂₂ )...(2). In reality, as shown in FIG. 5, the portion of the laser beam that deviates from the light-receiving surface 4 may not be visible to the naked eye, as indicated by the broken line in the drawing, but the above calculated value of point P 4 points on light receiving surface 4
It only contains the coordinates of A ₁ , A ₂ , B ₁ , and B ₂ . Therefore, even if point P cannot be visually observed, the coordinates of point P with respect to the coordinate axis xy can be identified. In the explanation of Fig. 5, four points on the outermost periphery C of the light receiving surface 4 are shown.
Although A ₁ , A ₂ , B ₁ , and B ₂ were used, it is not necessary to do so. For example, as shown in FIG. 6, for one straight line A (or B), two points inside the light receiving surface 4
It is sufficient if A ₁ and A ₂ (or B ₁ and B ₂ ) can be read.

In the above explanation, P was determined as the intersection of two straight lines A and B, but detection accuracy can be further improved by determining point P as the average value of the intersections of multiple straight lines as shown in Figure 4. can.

In this manner, the position detection method of the first invention can determine the optical axis (intersection P) of the band-shaped laser beam 2' even if it is off the light receiving surface 4. Therefore, the range of position detection is widened, and the area of the light-receiving surface 4 can be reduced, and the light-receiving device 3 can be downsized.

Figure 7 is an explanatory diagram of the state in which it is used in a tunnel excavation machine, etc., Figure 8 is a front view of the line sensor, Figure 9 is a graph with electrical output on the vertical axis and time on the horizontal axis.
FIG. 10 is an explanatory diagram of a state in which a band-shaped laser beam hits the light-receiving surface, and FIG. 11 is a block diagram showing the sequence of operations.

The position detection device of the second invention in this embodiment includes a laser beam emitting device 1', a light receiving device 3,
It consists of a calculation device 102 and a display device 103.

The laser beam emitting device 1' is configured to emit a band-shaped laser beam 2' and rotate the band-shaped laser beam 2' around the emission direction of the laser beam 2'. Use a scraping device.

The light receiving device 3 has a light receiving surface 4 on the front surface, and four line sensors 100- on the four sides of the light receiving surface 4.
1, 100-2, 100-3, and 100-4, respectively, and the x-axis, y-axis, and origin O are attached to the light-receiving surface 4. This line sensor 100-1, 10
0-2,100-3,100-4 has a length of 2a
They are arranged in the shape of a mouth as shown in FIG. 10, and their centers are located on the x and y axes. This line sensor 100-1, 100-2,
100-3 and 100-4 are, for example, 256 photodiodes arranged in one dimension,
An electrical signal is output according to the amount of light incident on the 256 photodiodes. Here, when the band-shaped laser beam 2' hits the n-th photodiode, a strong electric signal is output at the part corresponding to the n-th photodiode, as shown in FIG.

The arithmetic device 102 includes a line sensor 100-
1,100-2,100-3,100-4, the band-shaped laser beam 2' and line sensor 100-1,100-2,1
Read the intersection with 00-3 and 100-4 as described below, calculate the two straight lines A and B using the above equation (1) from the read intersection, and use the above equation (2) using the two straight lines A and B.
The intersection point P (optical axis of the belt-shaped laser beam 2') is determined by the step 12, and the coordinates of the intersection point P are output.

The display device 103 displays the intersection point P on the screen based on the coordinates of the intersection point P output from the arithmetic device 102.
It is constructed so that a spot is imaged at a position corresponding to . Note that this display device 103
In addition to forming a spot image of the intersection point P, it may also be one that displays the x and y coordinates of the calculation result of the intersection point P outputted from the calculation device 102 as numerical values.

Next, calculations in the above-mentioned calculation device 102 will be explained.

First, when the n-th photodiode among the 256 photodiodes is receiving light, its position is calculated and determined. That is, 256 photodiodes of the line sensor are scanned at a period of a predetermined time T. Then, when the n-th photodiode is receiving light, as shown in FIG. 9, the initial time t ₁
A strong electrical signal is output at time t _o after a time n/256T has elapsed since then. Therefore, by detecting the time point t _o at which a strong electrical signal is output among the electrical signals repeatedly output by the timer at a predetermined period of time T, the number of the 256 photodiodes can be calculated using the following formula (3). You can tell whether the photodiode is receiving light.

n=256×t _o /T...(2) Also, each photodiode is finished with extremely accurate dimensions, so if the width dimension of one photodiode is b, the above formula (3) For example, if the nth photodiode is detected in
As shown in the figure, it can be seen that the band-shaped laser beam 2' hits a location a distance nb away from the first photodiode (the leftmost photodiode).
In this way, the light receiving position of the line sensor can be determined.

Next, the straight line of the band-shaped laser beam 2' appearing on the light-receiving surface 4 is calculated and determined from the calculation result of the light-receiving position of the above-mentioned line sensor. For example, the 10th
As shown in the figure, when the straight line A of the belt-shaped laser beam 2' crosses the line sensors 100-1, 100-2 and appears on the light receiving surface 4, the line sensor 1
By outputting a strong electrical signal at the time corresponding to the n _1st photodiode of 00-1 and the n _2nd photodiode of the line sensor 100-2, positions bn ₁ and bn ₂ are respectively set according to the above principle. Desired. Here, straight line A is line sensor 100-
The coordinates of points A ₁ and A ₂ that cross 1,100-2 are A ₁
(x ₁₁ , y ₁₁ ), A ₂ (x ₁₂ , y ₁₂ ), then x ₁₁ = -a + bn ₁ , y ₁₁ = a x ₁₂ = a, y ₁₂ = a-bn ₂ ...(4) . From this equation (4), the coordinates of points A ₁ and A ₂ are found,
From the coordinates of these points A ₁ and A ₂ , the equation of straight line A can be found using the above equation (1).

Also, the belt-shaped laser beam 2' rotates and the first
As shown by the broken line in Figure 0, the line sensor 100
The coordinates of points B ₁ and B ₂ of straight line B when they appear on the light-receiving surface 4 across -3,100-4 can be found in the same way, and the equation of straight line B can also be found in the same way. .

Then, the coordinates of the intersection point P of the two straight lines A and B are determined by the equation (2) above using the equations of the two straight lines A and B determined as described above. The coordinates of this intersection P are output to the display device 103.

Figure 11 is a block diagram showing the sequence of operations.
The operation order will be explained below.

(a) First, a band-shaped laser beam 2' is emitted from the laser beam emitting device 1' toward the light receiving surface 4 of the light receiving device 3. At this time, a straight line A of the band-shaped laser beam 2' appears on the light receiving surface 4.

(b) While the straight line A of this band-shaped laser beam 2' appears on the light-receiving surface 4, that is, while the line sensor is receiving light, find the intersections A ₁ and A ₂ of the straight line A and the line sensor. , and further this intersection A ₁ ,
Find the equation of straight line A from A ₂ .

(c) Next, the belt-shaped laser beam 2' is rotated.
Then, a band-shaped laser beam 2' is formed on the light-receiving surface 4.
A straight line B appears.

(d) Similarly to (b) above, while the line sensor is receiving light, the intersection point B ₁ of the straight line B and the line sensor,
Find B ₂ and then find the equation of straight line B.

(e) Find the coordinates of the intersection point P of the two straight lines A and B using the equation for A in (b) and the equation for B in (d) above,
The coordinates of this intersection P are output to the display device 103.

As described above, the position detection device of the second invention in this embodiment can electrically determine the optical axis of the strip-shaped laser beam 2', and therefore can accurately and quickly detect the light of the strip-shaped laser beam 2'. The relative position of the light receiving device 3 with respect to the axial position can be detected. Moreover, since the optical axis of the belt-shaped laser beam 2' is determined by rotating the belt-shaped laser beam 2', the optical axis can be determined even if the optical axis of the belt-shaped laser beam 2' is off the light receiving surface 4. be able to. Therefore, the position detection range becomes wider, and the area of the light-receiving surface 4 can be reduced, and the light-receiving device 3 can also be made smaller.

In the above embodiment, the optical axis of the belt-shaped laser beam 2' was determined from the two straight lines A and B, but the intersection point P was determined as the average value of the intersections of many straight lines.
(the optical axis of the belt-shaped laser beam 2') may be determined. In this case, detection accuracy is further improved.

〔Effect of the invention〕

As is clear from the above embodiments, the position detection method of the present invention emits a band-shaped laser beam, rotates the band-shaped laser beam, and reads at least two straight lines among the straight lines appearing on the light receiving surface. This method determines the optical axis of the laser beam and detects the relative position of the photodetector to the optical axis of this band-shaped laser beam. Therefore, even if the optical axis of the band-shaped laser beam deviates from the light-receiving surface, the position can be detected. It can be carried out. Therefore, the light receiving device can be downsized.

Further, since the position detection device of the present invention electrically determines the optical axis of the band-shaped laser beam, it is possible to accurately and quickly detect the position. Moreover, the light receiving device can be downsized.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a state in which a conventional position detection method is used in a tunnel boring machine or the like. Figures 2 to 6 show an embodiment of the position detection method of the present invention, Figure 2 is an explanatory diagram showing the state in which it is used in a tunnel boring machine, etc., and Figure 3 is an illustration in which the optical axis is within the light receiving surface. Fig. 4 is an explanatory diagram of the light-receiving surface showing the case where the optical axis is off the light-receiving surface, Fig. 5
The figure is an explanatory diagram for reading the straight line of a band-shaped laser beam appearing on the light-receiving surface from a point on the outermost circumference of the light-receiving surface.
FIG. 6 is an explanatory diagram for reading a straight line of a band-shaped laser beam appearing on the light receiving surface from a point inside the light receiving surface. 7 to 11 show an embodiment of the position detection device of the present invention, FIG. 7 is an explanatory diagram of the state in which it is used in a tunnel excavator, etc., FIG. 8 is a front view of the line sensor, and FIG. 9 is a graph in which the vertical axis represents the electrical output and the horizontal axis represents time; FIG. 10 is an explanatory diagram of a state in which a band-shaped laser beam is applied to the light-receiving surface; and FIG. 11 is a block diagram showing the sequence of operations. 1'... Laser beam emitting device, 2'... Band-shaped laser beam, 3... Light receiving device, 4... Light receiving surface,
100-1,100-2,100-3,100-
4...Line sensor, 102...Arithmetic device, 10
3...Display device, A, B...straight lines appearing on the light-receiving surface 4, P...intersection of two straight lines A, B (optical axis of band-shaped laser beam 2').

Claims (1)

[Claims] 1. A laser beam emitting device emits a band-shaped laser beam onto the light-receiving surface of a light-receiving device, and the band-shaped laser beam is rotated around the emission direction, so that the band-shaped laser beam appearing on the light-receiving surface is Read at least two of the straight lines, find the intersection of the read straight lines, and use the found intersection to determine the relative position of the light receiving device with respect to the optical axis position of the belt-shaped laser beam emitted from the laser beam emitting device. A position detection method characterized by detecting. 2. A laser beam emitting device configured to emit a belt-shaped laser beam and rotate the belt-shaped laser beam around the emission direction, a light receiving device having a light receiving element on its light receiving surface, and a light receiving device connected to the light receiving element. , an arithmetic device that reads at least two of the straight lines of the belt-shaped laser beam that crosses the light receiving element and finds the intersection of the plurality of read straight lines, and the laser beam is emitted based on the intersection point found by the arithmetic device. 1. A position detection device that detects the relative position of the light receiving device with respect to the optical axis position of a band-shaped laser beam emitted from the device.