KR100976597B1 - Calibration device for non-contact measurement system - Google Patents

Abstract

The present invention relates to a calibration device for a non-contact measurement system, comprising: a case in which a bevel and a face in which a vertex is formed by cutting a vertex from an English letter V shape at an opposing position of a line beam irradiated by the non-contact measurement system and a case are disposed; It includes a camera disposed inside the line to shoot the laser beam image confronted in the line beam, the moving axis of the motorized stage by shooting the laser beam image by the line beam of the laser generator through a camera installed inside the calibration device And it is possible to measure the alignment of the line beam irradiated by the laser generator, and the accurate three-dimensional information of the singularity extracted from the laser band formed on the calibration device is obtained has the advantage that can perform a very high precision calibration.

Non-contact Measurement, Calibration, Jig

Description

Calibration device for non-contact measurement system {CALIBRATION APPARATUS FOR NONCONTACT MEASURING SYSTEM}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a calibration device for a non-contact metrology system, and more particularly to a calibration device capable of reflecting the alignment state of a laser generated by the non-contact metrology system.

Typically, an outer panel of a ship is composed of a curved sheet member of about 10 mm to 30 mm in thickness with a complex non-developing curved surface to reduce propulsion resistance so that the ship can navigate efficiently under water. Through a process called linear heating, the steel sheet is processed into a desired shape through out-of-plane deformation or in-plane shrinkage deformation due to plastic deformation generated by locally heating the surface of the steel sheet using a gas burner or the like.

In addition, for the workpiece such as the curved member of the vessel processed as described above, it is necessary to measure whether or not the precise processing in the desired form, the measurement and production of the curved member of the vessel using a tape measure, a hand tool, a hieroglyphic shape of the wood material, etc. Measurement by human was performed.

Measurement of such curved member is used for cutting line marking operation after completion of work evaluation, heating line generation and processing.

By the way, according to the measurement technique performed manually by a person, the measurement of the large curved sheet member depends on the manual operation, which takes a lot of measurement time and has many problems such as a decrease in the accuracy of the measurement data. In particular, the curved plate member used in the fore and aft portion of the vessel is more diverse in shape and processed and measured using a pre-curved wood material of the pre-made wood material for each part, most of the material of the hieroglyphic shape is made of wood and the desired curved shape As a curved member is repeatedly used many times for the accurate machining of the member, plastic deformation occurs due to various peripheral factors such as ambient temperature and operator's neglect. There was a difficult problem in accurate machining and measurement.

On the other hand, in order to solve the problem of the manual measurement technology, a non-contact measurement system for measuring the shape of the member to be measured in a non-contact manner has been proposed.

Such a non-contact measurement system may be referred to as a laser vision system, and may include a laser generator for irradiating a line-type laser beam to a member to be measured, a camera for photographing a laser beam image emitted to the member to be measured, and the like. In addition, the laser generator and the camera are modularized by being installed integrally with the fixture.

Such a non-contact measuring system may be installed and used at the end of the welding robot to track the welding line of the welding robot.

On the other hand, the non-contact measurement system is typically coupled to the coupling body such as a welding robot in a detachable state, which is basically used after the calibration process in order to improve the accuracy of the curved member measurement or welding seam tracking, in the calibration process Jig is used.

1A is a conceptual diagram illustrating a calibration process using a calibration jig according to an exemplary embodiment.

As shown in FIG. 1A, the calibration jig 20 uses the triangular box shape to form an English letter V on the same plane as the line beam 31 irradiated by the laser generator 11 of the non-contact measurement system 10. It is arranged so that the shape of the inclined surface, the calibration jig 20 is moved along a predetermined path by a motorized stage (not shown), the camera 13 of the non-contact measurement system 10 is a calibration jig ( The laser beam image 33 by the line beam 31 irradiated to 20 is photographed.

The laser beam image 33 captured by the camera 13 by the calibration process is as shown in FIG. 1B, and the coordinates of the vertices 35 extracted from the laser beam image 33 and the electric stage (not shown). A method of extracting the transformation matrix parameter using the coordinate of) is used.

The calibration method described with reference to FIGS. 1A and 1B proceeds on the assumption that the plane in which the laser is scanned is parallel to the axis of movement of the motorized stage. This is because at present, only the X and Y axis coordinates of the transmission stage can be obtained from the three-dimensional information. To meet this assumption, the operator uses a calibration device to make the scanning direction of the laser parallel to the motorized stage.

2 is a perspective view showing the configuration of a calibration device according to the prior art.

As shown in the figure, the calibration device 40 includes a distance adjusting frame 41 and a calibration jig 43. The distance adjusting frame 41 is provided with a distance adjusting groove 41a to move the calibration jig 43 by sliding the horizontal coordinate, that is, the z coordinate, and the calibration jig 43 is provided by the laser generator 11. The ruler 43a is provided so that the laser strip 45 by the irradiated laser is formed.

The laser emitted from the non-contact measurement system 10 has to be converted into three-dimensional data in order to know the exact welding position because the received data is two-dimensional. At this time, since the pitch angle of the laser with respect to the reference coordinate cannot be applied to the calibration matrix, the distance between the non-contact measurement system 10 and the calibration jig 43 and the distance of the laser beam is utilized by utilizing the calibration jig 43 having the ruler 43a. The height, or pitch angle, is measured.

According to the calibration apparatus according to the prior art as described above, not only takes a long time to perform the calibration, but also determines the parallelism by visual observation of the operator, so that the calibration operator may perform calibration based on different standards. There was a low issue.

The present invention has been proposed to solve such a problem of the prior art, and the singularity extracted from the laser band formed in the calibration device by measuring the alignment of the moving axis of the electric stage for moving the calibration device and the line beam irradiated by the laser generator It obtains accurate 3D information of and enables calibration of very high accuracy.

The calibration device of the non-contact measurement system according to the present invention is a case in which the oblique surface and the face of the form in which the vertex is cut out and extended from the letter V (V) shape at the opposite position of the line beam irradiated by the non-contact measurement system, and the case; It is disposed in the interior of the line beam includes a camera for taking a laser beam image of the facing.

Here, the calibration device further includes an electric stage for moving the case along a predetermined path, the case is a trapezoidal box shape, the facing of the case is preferably a semi-permeable material.

The present invention can measure the alignment state of the moving axis of the motorized stage and the line beam irradiated by the laser generator by photographing the laser beam image by the line beam of the laser generator through a camera installed inside the calibration device, The accurate three-dimensional information of the singularity extracted from the laser band formed on the calibration device is obtained, which has the effect of performing a very high precision calibration.

To calibrate a non-contact metrology system, the axis of motion of the motorized stage moving the calibration jig (or calibration device) and the line beam irradiated from the laser generator must be perfectly parallel. However, this parallel state is almost impossible physically. Therefore, in the present invention, by installing a camera inside the calibration device to shoot the laser beam image by the line beam irradiated by the laser generator can measure the alignment state of the moving axis of the motorized stage and the line beam irradiated by the laser generator It would be.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

3 is a conceptual diagram illustrating a calibration process using a calibration device according to the present invention, Figure 4 is a block diagram showing the internal structure of the calibration device according to the present invention.

As shown in FIGS. 3 and 4, in the calibration device 200 of the present invention, a case 210 in the form of a trapezoidal box has a slant face 211 and a face 213, and a laser generator of the non-contact measurement system 100 ( On the same plane as the line beam 301 irradiated by 110, the inclined plane 211 and the face 213, which are formed by cutting out vertices in the shape of an English letter V, are placed at opposite positions of the line beam 301. The camera 220 is disposed inside the case 210 to photograph the laser beam image 401 formed on the facing 213 of the line beam 301 irradiated by the laser generator 110. The calibration device 200, that is, the case 210, moves along a predetermined path by a stage (not shown), and the camera 130 of the non-contact measurement system 100 emits a line beam (radiated to the calibration device 200). The laser beam image 303 by the 301 is photographed.

The face 213 of the case 210 is made of a semi-transparent material so that the line beam 301 irradiated by the laser generator 110 is formed on the outside of the face 213, and installed inside the case 210. The camera 220 photographs the inside of the face 213 so as to capture the laser beam image 401 formed on the outside of the face 213.

Looking at the calibration process using the calibration device according to the present invention configured as described above are as follows.

First, the line beam 301 irradiated from the laser generator 110 of the non-contact measurement system 100 is irradiated to the calibration device 200 arranged to be movable through a predetermined moving axis by a transmission stage (not shown). .

Then, the camera 130 of the non-contact measurement system 100 captures the laser beam image 303 by the line beam 301 irradiated to the calibration device 200. Here, as shown in FIG. 5A, when the laser beam image 303 obtained by the line beam 301 irradiated to the calibration device 200 is obtained, the intersection point is extracted as the singular point 305 by extending the laser band formed on the inclined plane 211. The singularity 305 extracted here corresponds to the vertex 35 of FIG. 1B.

The camera 220 installed in the calibration apparatus 200 captures the laser beam image 401 formed on the facing surface 213 of the line beam 301 irradiated by the laser generator 110. Here, as shown in FIG. 5B, when the laser beam image 401 formed on the face 213 is obtained from the line beam 301 irradiated by the laser generator 110, the singular point 403 is extracted at a predetermined position of the laser strip.

In the example of FIG. 5B, the horizontal solid line is a line beam 301 irradiated by the laser generator 110 and formed on the face 213, and the horizontal dotted line is a line formed on the face 213 for extraction of the singularity 403. The first virtual line extending the beam 301 and the vertical dotted line are the second virtual lines intersecting the first virtual line for extraction of the singularity point 403. In this case, the second virtual line intersects the midpoint of the first virtual line, that is, intersects with the first virtual line in the middle of the screen of the camera 220, which extracts the singularity point 403 based on the optical design value of the camera 220. It is because it is used when calculating the relative height value of (301).

Therefore, when the laser beam image 303, 401 is photographed using two cameras 130 and 220 while moving the calibration apparatus 200 using the electric stage, the moving shaft and the laser generator 110 of the electric stage are moved. The alignment of the line beam 301 to be irradiated may be measured.

Therefore, accurate three-dimensional information of the singularity 305 extracted by extending the laser band formed on the oblique surface 211 of the calibration device 200 is obtained, and the transformation matrix parameter is obtained by using the coordinates of the singularity 305 and the coordinates of the transmission stage. If you perform the calibration to extract the calibration can be performed with a very high precision.

It has been described so far limited to one embodiment of the present invention, it is obvious that the technology of the present invention can be easily modified by those skilled in the art. Such modified embodiments should be included in the technical spirit described in the claims of the present invention.

1A is a conceptual diagram illustrating a calibration process using a calibration jig according to the prior art;

Figure 1b is an example of a laser beam image taken by the calibration process according to the prior art,

2 is a perspective view showing the configuration of a calibration device according to the prior art,

3 is a conceptual diagram illustrating a calibration process using a calibration device according to the present invention;

4 is a block diagram showing the internal structure of the calibration device according to the present invention,

5A is an example of a laser beam image photographed by a non-contact measurement system by a calibration process according to the present invention;

Figure 5b is an example of a laser beam image taken by the calibration device by the calibration process according to the present invention.

<Brief description of the major symbols in the drawings>

100: non-contact measurement system 110: laser generator

130, 220: camera 200: calibration device

210: Case 211: Slope

213: facing

Claims (4)

A case in which a bevel and a face are arranged at opposite positions of the line beam irradiated by the non-contact measurement system, in which the vertex is cut out and extended from the English letter V shape; A camera disposed inside the case to capture a laser beam image of the line beam in the face beam; Calibration device of a non-contact measurement system comprising a. The method of claim 1, Electric stage to move the case along a predetermined path Calibration device of the non-contact measurement system further comprising. The method of claim 1, The case is trapezoidal box shape Calibration device for in-contact measurement system. The method according to claim 1 or 3, The facing of the case is a semi-permeable material Calibration device for in-contact measurement system.

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