JPH0753342B2 - Work position correction method with CCD camera - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is applied to a case where a work is mounted on one or more processing machines such as a punch press or a laser machine more than once, and the processing is performed.
The present invention relates to a method for correcting a work position using a CD (charge coupled device) camera.

[0002]

2. Description of the Related Art In composite machining, in which a work is replaced with a work machine for machining, the work is displaced due to the replacement. In order to detect this displacement with a CCD camera, conventionally, the displacement amount of the work is measured with the central position in the image memory of the CCD camera as a reference point.

That is, the CCD camera attached to the machining head of the post-machining machine is moved to the coordinate position of the reference hole machined in the work by the pre-machining machine, the reference hole is photographed by the CCD camera, and the CCD camera is operated. The center position of the image of the reference hole in the image memory is detected, and the shift amount of the center position of the image of the reference hole with respect to the reference point at the center of the image memory of the CCD camera is converted into the shift amount of the work.

[0004]

However, in the method of measuring the deviation amount of the work and correcting the work position as described above, the separation distance between the machining axis of the machining head and the camera axis of the CCD camera is accurately measured. If not measured, the reference point is CC
The deviation of the distance from the center of the image memory of the D camera greatly affects the measurement accuracy of the work deviation amount. Also, when attaching the CCD camera to the processing head,
The mounting state is not always constant, and the camera may be tilted and the optical axis may be displaced in addition to the separation distance of the machining head from the machining axis, and there is a problem that handling is troublesome and errors are likely to occur as a whole. .

In the present invention, the C with respect to the machining axis of the machining head is used.
An object of the present invention is to provide a work position correction method using a CCD camera that can accurately measure a work deviation amount and correct the work position without being affected by the separation distance of the CD camera and the deviation of the optical axis. And

[0006]

In order to achieve the above-mentioned object, the present invention processes a basic hole by a post-machining machine at an appropriate position of a work pre-machined by the pre-machining machine and mounted on the post-machining machine. And the CCD camera attached to the processing head of the post-processing machine is moved to the coordinate position of the basic hole, the basic hole is photographed by the CCD camera, and the basic hole in the image memory of the CCD camera is recorded. The basic hole detection process to detect the center position of the image and the CCD camera in the post-processing machine,
A reference for moving the workpiece on the post-processing machine to the coordinate position of the reference hole processed by the pre-processing machine, photographing the reference hole with the CCD camera, and detecting the center position of the image of the reference hole in the image memory of the CCD camera. The hole detection step and the correction step of correcting the work position by comparing the center positions of the images of the basic hole and the reference hole in the image memory of the CCD camera and calculating the difference therebetween are provided.

[0007]

When the CCD camera is moved to the coordinate position in the post-machining machine of the basic hole machined by the post-machining machine, the separation distance of the machining head of the CCD camera from the machining axis is set conveniently and the CCD camera is attached. The machining head is moved by the above set distance to move the CCD camera to the coordinate position of the basic hole.

In this way, the CCD camera is moved to the position of the basic hole and the basic hole is photographed. In this case, the center position of the image of the basic hole in the image memory of the CCD camera is obtained from the basic hole of the post-processing machine, and this is used as the reference point. This is because even if there is an error between the separation distance set for convenience of the CCD camera with respect to the processing axis of the processing head and the actual separation distance, or the optical axis of the CCD camera is tilted. , It does not change unless the relationship between the processing head and CCD camera is broken.

Therefore, when the CCD camera is moved to the coordinate position of the reference hole processed by the pre-processing machine and the reference hole is photographed, the coordinate error between the post-processing machine and the pre-processing machine, that is, the post-processing machine. The positional deviation of the work is indicated by the difference (deviation) between the central position of the image of the basic hole and the central position of the image of the reference hole in the image memory of the CCD camera.
This difference is converted into an actual size on the work and the work position is corrected based on this.

[0010]

1 shows an NC laser machine embodying the present invention. The laser machine 1 is used for post-processing of the work W, and the processing head 2 has a laser processing tool 3
And a CCD camera 4. The processing head 2 is a driving device (not shown) in the left-right direction in FIG. 1 and in the direction perpendicular to the paper surface.
The laser processing tool 3 is attached to an arbitrary processing position of the work W, and the CCD camera 4 is attached to an arbitrary imaging position. The laser processing tool 3 has its central axis aligned with the processing axis of the processing head 2. The basic structure of the laser machine 1 is well known.

An example of the present invention will be described for the case where the product S shown in FIG. 3E is manufactured by the laser machine 1 and the NCT punch press (not shown). The work W is attached to a punch press which is a pre-processing machine, and as shown in FIG. 3A, a product hole Wa and a positioning reference hole Wb are processed. The work W in which the product hole Wa and the reference hole Wb are processed is removed from the punch press, and the laser machine 1, which is a post-processing machine, is mounted.

In the laser machine 1, first, a basic hole Wc is formed at an appropriate position on the work W as shown in FIG. In this case, it goes without saying that the laser processing tool 3 is moved by the processing head 2. Next, the CCD camera 4 is moved by the processing head 2 onto the basic hole Wc as shown by the chain double-dashed line in FIG. The above-mentioned movement of the CCD camera 4 is performed by presetting the machining axis of the machining head 2 and CC.
This is performed based on the separation distance of the D camera 4.

That is, the distance between the processing axis of the processing head 2 (laser processing tool 3) and the CCD camera 4 is, for example,
When L is 0 in the X-axis direction and 0 (zero) in the Y-axis direction, the CCD camera 4 is moved by L in the X-axis direction from the state where the laser processing tool 3 is attached to the center position of the basic hole Wc. The above separation distance measurement does not require accuracy,
The value is set in the NC device.

After the basic hole Wc is photographed by the CCD camera 4, image processing is performed and the image memory (screen) of the CCD camera 4 is displayed.
Center position WcO of image WcA of basic hole Wc in 4a
Is detected and stored as a reference point (X0, Y0).

Next, the CCD camera 4 is moved above the reference hole Wb. At this time, the CCD camera 4 is moved based on the coordinates of the reference hole Wb and the above-mentioned separation distance. More specifically, an example of this movement will be described. After the laser processing tool 3 is placed at the coordinate position of the reference hole Wb, the CCD camera 4 is moved by the separation distance L in the X-axis direction.

After moving the CCD camera 4 onto the reference hole Wb in this way, the CCD camera 4 photographs the reference hole Wb and performs image processing. By this image processing, the center position WbO (X1, Y1) of the image WbA of the reference hole Wb in the image memory 4a of the CCD camera 4 is detected.

In the laser beam machine 1, if there is no displacement of the work W, the center position of the image WbA of the reference hole Wb is the center position of the image WcA of the basic hole Wc stored as the reference point in the image memory 4a of the CCD camera 4. Wb
O will match correctly. In other words, the center position Wc of the image WcA of the basic hole Wc in the image memory 4a.
The positional deviation between the center position WbO of the image WbA of O and the reference hole Wb indicates the positional deviation of the work W.

Therefore, the basic hole W in the image memory 4a
The center coordinates (X0, Y0) of the image WcA of c and the reference hole Wb
From the difference from the center coordinates (X1, Y1) of the image WbA of the image WbA, the dot shift amount (X0−X) of the X axis in the image memory 4a.
1) and the dot shift amount (Y0-Y1) on the Y axis are calculated. Next, the above-mentioned dot shift amounts (X0-X1), (Y0-Y1)
Is multiplied by the length of the work W per dot in the image memory 4a to convert it to the actual deviation amount of the work W, and X
The amount of axis correction and the amount of Y axis correction are calculated.

The X-axis and Y-axis correction amounts calculated above are set to NC.
The device S is set and the product S is processed.

In the above description, an example of combined processing using a punch press and a laser machine has been described, but the type and combination of processing machines are not limited to the above, and the number of processing machines and the number of combined processing are also arbitrary. is there. Normally, two work holes Wb are processed for one work W, and two work holes are processed for each product when a large number of work pieces are taken, but there may be one work hole depending on the product.
In the case of an NC machine, the method of the present invention is automatically controlled by an NC device, and in the case of a computer-controlled processing machine, it is usually automatically controlled by a computer.

[0021]

As described above, according to the work position correcting method using the CCD camera of the present invention, a basic hole is formed by the post-processing machine at an appropriate position of the work pre-processed by the pre-processing machine and mounted on the post-processing machine. Basic hole drilling process and the CCD camera attached to the processing head of the post-processing machine are moved to the coordinate position of the basic hole, the basic hole is photographed by the CCD camera, and the basic hole in the image memory of the CCD camera is processed. Basic hole detection step of detecting the center position of the image of the image, and the CCD camera in the post-processing machine is moved to the coordinate position of the reference hole processed by the pre-processing machine on the work on the post-processing machine, and the CCD camera performs the reference The reference hole detection step of photographing the hole to detect the center position of the image of the reference hole in the image memory of the CCD camera, and the center position of the image of the basic hole and the image of the reference hole in the image memory of the CCD camera are described. In comparison, the difference between the machining axis of the machining head and the camera axis of the CCD camera is measured and the optical axis of the CCD camera is measured. It is not necessary to use nerves for misalignment, and even if there is an error or misalignment in them, it is possible to always accurately know the amount of misalignment of the work position by a simple operation, and correct this to improve the machining accuracy.

[Brief description of drawings]

FIG. 1 is a front view of a laser machine.

[Fig. 2] Basic hole and reference hole and CC machined in the work
It is sectional drawing which shows the relationship of a D camera and the like.

FIG. 3 is a plan view showing an embodiment of the present invention.

[Explanation of symbols]

 1 Laser Machine (Post Processing Machine) 2 Processing Head 3 Laser Processing Tool 4 CCD Camera 4a Image Memory W Work Wa Product Hole Wb Reference Hole WbA Image WbO Center Position Wc Basic Hole WcA Image WcO Center Position

Claims (1)

[Claims] 1. A basic hole drilling process for drilling a basic hole by a post-machining machine at an appropriate position of a work pre-machined by the pre-machining machine and mounted on the post-machining machine, and attached to a machining head of the post-machining machine. A basic hole detection step of moving the CCD camera to the coordinate position of the basic hole, photographing the basic hole with the CCD camera, and detecting the center position of the image of the basic hole in the image memory of the CCD camera; CCD camera,
A reference for moving the workpiece on the post-processing machine to the coordinate position of the reference hole processed by the pre-processing machine, photographing the reference hole with the CCD camera, and detecting the center position of the image of the reference hole in the image memory of the CCD camera. A work by a CCD camera, comprising: a hole detection step; and a correction step of comparing the center positions of the images of the basic hole and the reference hole in the image memory of the CCD camera and calculating the difference between them to correct the work position. Position correction method.