JPH0311643B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a center detection device suitable for application to, for example, a laser-applied excavation direction reference device of a tunnel excavation device.

[Conventional technology]

To control the direction of movement of the tunnel excavation machine,
A laser is installed at the starting point of the digging machine, a light receiving surface is provided in the digging machine part, and by knowing which position on the light receiving surface is irradiated by the laser beam, the machine is controlled so that it can move in the desired direction. things are being done.

In this case, cylindrical lenses 1 and 2 are arranged in the X direction and in the Y direction perpendicular to this, respectively, as shown in FIG. A thin image is formed on the arranged CCD linear image sensors 3 and 4, and the image formation position is obtained from these image sensors 3 and 4 in the form of an electric signal, which is displayed digitally or converted into an analog signal. The position of the irradiated image on the light-receiving surface is electrically determined. In the figure, 5X and 5Y are beam images, and 6X and 6Y are light-receiving surfaces of a sensor in which photodetecting elements S as picture elements are arranged in a row in the Y direction and the X direction, respectively.

[Problem that the invention seeks to solve]

However, although the irradiated image on the light receiving surface ideally becomes a line, in reality, as the distance between the light source and the light receiving surface becomes long, the images 5X and 5Y have a wide width as shown in FIG. 6A. In addition to making it difficult to know the center with certainty, the image 5
If X and 5Y are off the center of the light-receiving surfaces 6X and 6Y and the ends of the light-receiving surfaces 6X and 6Y are irradiated in a half-moon shape, it becomes even more difficult to detect the center.

An object of the present invention is to accurately calculate and detect the beam center even when a laser beam forms a fairly wide image on the light receiving surface, and to prevent the beam center from protruding outside the light receiving surface and forming a part of the image. By accurately detecting the center of the beam, even when the beam overlaps the light-receiving surface, the light-receiving area can be designed to be smaller, and the center of the beam will be removed from the light-receiving surface when constructing a curved tunnel. Make it possible to know the exact coordinates even in the state of
The purpose is to be able to obtain automatic control signals even during curved construction.

[Means for solving problems]

In the present invention, there is provided an address counter 12 in which addresses are sequentially set for the photodetecting elements arranged in one row of the image sensor, and the count contents of this address counter 12 are read from the photodetecting elements arranged in one row of the image sensor. A first latch means 17 that latches when the output rises and a second latch means 18 that latches when the output falls are provided. Find the center position of the incident light beam.

[Effect]

The sum of the latch outputs of the two latch means 17 and 18 is twice the address value on the image sensor corresponding to the center position of the incident light beam, and the center position can be determined from this value. Furthermore, since the value of the difference between the latch outputs of the two latch means 17 and 18 corresponds to the beam diameter, when the incident light beam protrudes from the light receiving surface of the image sensor and forms a half-moon image,
By adding or subtracting the radius value determined from the beam diameter to the address value of the edge of the image, the center position of the incident beam can be accurately determined.

〔Example〕

FIG. 1 shows an embodiment of the inventive device, and for the sake of simplicity, the figure shows only the X-direction of the cylindrical lenses in both the X and Y directions. Similar processing circuitry is required for both directions.

In the same figure, 10 is a CCD image sensor,
In this example, the photodetector element S as 256 picture elements
are linear image sensors arranged in a line in the X direction.

Reference numeral 11 denotes a clock generation circuit, and the clock from this circuit sequentially reads the video output from each photodetection element section S of the image sensor 10, and the clock from this clock generation circuit 11 is supplied to the address counter 12. The addresses of the photodetector elements in one row in the X direction are "0", "1",
"2"... are sequentially designated. In this case, the counter 12 is an 8-bit counter, and as shown in FIG. 2, the address when the video output is read out from the leftmost photodetecting element section S of the light receiving surface 10a of the image sensor 10 is "0". , the address increases by "1" as it moves to the right side, and the address is "255" in the rightmost photodetecting element section S.
It is becoming like this.

Now, assuming that the image of the light incident on the light receiving surface 10a through the cylindrical lens in the X direction is as shown by 6 in FIG. 2, the image sensor 10
The video signal read out from the waveform shaping circuit 13
A waveform-shaped output SA as shown in FIG.

The waveform-shaped output SA is also supplied to a rise detection circuit 15 and a fall detection circuit 16, and detection pulses P ₁ and P ₂ (FIG. 3 B and C) are obtained at the rise and fall points of the output SA, respectively. . The count value of the address counter 12 is latched in the latch circuits 17 and 18 by these detection pulses P ₁ and P ₂ . What is latched by the latch circuit 17 is the count value of the address counter 12 at the time of the rise of the signal SA, that is, the address value Am, and what is latched by the latch circuit 18 is the count value of the address counter 12 at the time of the fall of the signal SA. That is, the address value Bm.

The outputs of these latch circuits 17 and 18
Am and Bm are supplied to the arithmetic circuit 14, and the output P ₁ of the rise detection circuit 15, the output P ₂ of the fall detection circuit 16, and the count value output of the address counter 12 are also supplied to the arithmetic circuit 14, and the following processing is performed. The center position of the incident light beam in the X direction is determined according to the procedure.

Figure 4 is a flowchart of this process. First, the flag F, which becomes "1" when the radius of the beam image is determined, is
is cleared (step [101]). Next, the address counter 12 is cleared to set the address value to "0" (step [102]), and reading of the video output from the CCD image sensor 10 is started. Then, it is determined from the output SA of the waveform shaping circuit 13 whether the output SA is at a high level at address "0" (step [103]). This is to determine whether the beam image has shifted to the left of the light receiving surface 5 as shown in FIG. 5B. This step [103]
In this determination, if the output SA is not at a high level, the clock sequentially reads data from the image sensor 10 and the count value of the address counter 12 increments. And the output
When the address value reaches "255" or higher without SA rising to a high level, it means that the image of the incident light beam is not formed on the light receiving surface.
It is determined (step [104]) and an error message is displayed, for example. When the waveform shaping output SA rises to a high level before the address count value reaches "255", this is determined by the pulse _P1 (step [105]), and the address value is set in the latch circuit 17.
Am is latched and taken into the arithmetic circuit 14 (step [106]).

Furthermore, the address count value advances from Am,
If it is determined that the waveform shaping output SA falls to a low level before reaching "255" (steps [107], [108]), the address count value Bm at the time of the fall becomes the pulse _P2. The signal is latched and taken into the arithmetic circuit 14. In this way, both address values Am and Bm can be obtained because the output SA is the third
This is the state shown in FIG. A, in which the beam image is focused on the light-receiving surface 10a.

At this time, the arithmetic circuit 14 uses both address values.
The diameter Φ of the beam in the X direction is determined as the difference between Am and Bm (step [110]), and the value of this diameter Φ is stored in the memory (step [111]). and,
Set the flag F to F = "1" (step [112]), and set the value of the center of the beam image in the X direction to Bm-
It is obtained as Φ/2 (step [113]).

In this case, the center value is (Am+Bm)/
It can also be determined by the following calculation.

Although the rising edge of the waveform shaping output SA was detected,
When the address count value reaches "255" without detecting a falling edge, the image of the incident light beam is off the right side of the light receiving surface 10a, and the waveform shaping output is
The SA is as shown in Figure 3D. When it is determined that this is the case (step [107]), it is determined whether the flag F is set to "1", that is, whether the beam diameter Φ is known (step [201]). When the diameter Φ is known, the value of the center is Am + Φ/2, and even though the beam image 6 protrudes from the light receiving surface 10a, the correct value of the center position can be found (step [202] ).

When the beam diameter Φ is unknown, in this example, the center value Am + 255 - Am / 2 when the falling position is exactly at the address value "255" is calculated as the value of the center position (step [203]) .

Next, when it is determined in step [103] that the waveform shaping output SA has been at a high level since the address value "0", the waveform shaping output SA is
The falling edge of is detected (step [301],
[302]), when a falling edge is detected, that is, when the beam image shifts further to the left than the left end of the light-receiving surface 10a and the waveform shaping output SA becomes as shown in FIG. The address count value Bm at the time of falling is latched in the latch circuit 18 (step [303]), and taken into the arithmetic circuit 14. Then, it is determined whether the flag F is set to "1", that is, whether the beam diameter Φ is known (step [304]), and if it is known, the center position is set as Bm - Φ/2, and the beam diameter is Although the image 6 protrudes from the light-receiving surface 10a,
The value of the correct center position is determined (step [305]). On the other hand, when the beam diameter Φ is unknown,
In this example, the center value Bm/2 when the rising position is the address count value "0" is obtained as the center position output (step [306]).

Furthermore, in step [103], it is determined that the waveform shaping output SA has been at a high level since the address value "0", and furthermore, the waveform shaping output SA has not fallen by the time the address count value reaches "255". In other words, when the incident beam is very thick as shown in Fig. 3F, the light receiving surface 1 is
If it completely exceeds 0a, the value "128" at the center of the light-receiving surface is output as the center value for convenience (step [307]).

The value of the position of the beam center thus obtained is converted into an analog voltage by the D/A converter 19 (step [100]), and is used, for example, as a voltage for controlling the advancing direction of the digging machine. And this D/
When the output voltage is taken out in step [100] by the A converter 19, the process moves to step [102], and the above-described steps of detecting the center position of the incident beam are repeated at a predetermined period until an end command is input.

Therefore, even if the image on the receiving surface of the beam protrudes during the operation of detecting the center position of the beam, the diameter of the beam is stored in the memory.
The correct center position can always be found.

Although the block diagram in Figure 1 shows the basic hardware configuration, in reality this invention can be realized using a microcomputer, in which case the CCD image sensor 10, waveform shaping circuit 13 and the D/A converter 19 are only connected to the microcomputer, and other circuits can be realized in the microcomputer.

In addition, it is not a CCD linear image sensor, but
Center detection can be performed in almost the same way using a CCD area image sensor.

〔Effect of the invention〕

According to this invention, it is possible to accurately know the position of the center of the incident light beam, even if it has a certain size, rather than the point.

In particular, when applied to a digging direction reference device for a tunnel digging device with a small diameter, the center position of the incident light beam can be accurately determined even when the image of the incident light beam protrudes from the light receiving surface. Therefore,
Even if the light receiving surface is small, the same effect as having a large light receiving surface can be obtained.

Also, if the tunnel Hori Susumu is the Curved Hori Susumu,
Even if the incident light beam moves within the light-receiving surface, the area in which the center can be detected is wide, so there is an effect that a signal for automatic control of the digging direction can be obtained while maintaining linearity over a large curved range.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an example of the device of this invention, FIGS. 2 and 3 are explanatory diagrams, FIG. 4 is a flowchart of the main part of this invention, and FIG.
The figure shows an example of the optical system of the laser beam light receiving section, and FIG. 6 is a diagram for explaining the beam image on the light receiving surface. 10 is a CCD image sensor, 12 is an address counter, 13 is a waveform shaping circuit, 15 is a rising detection circuit, 16 is a falling detection circuit, and 17 and 18 are latch circuits.

Claims (1)

[Claims] 1. An address counter in which addresses are sequentially set for the photodetecting elements arranged in a line of the image sensor, and the rising edge of the output read out from the photodetecting elements arranged in the line of the image sensor to read out the count contents of this address counter. the center of the light beam incident on the image sensor from the latched contents of the first and second latching means; In the center detecting device for determining the position, a memory is provided for determining the diameter of the incident light beam from the latched contents of the first and second latching means and storing the diameter, and the incident beam is arranged to detect the diameter of the incident light beam on the image sensor. A center detection device for determining the center position of the incident light beam when the incident light beam protrudes from the light receiving surface from the contents of the first latching means or the second latching means and the beam diameter from the memory.