JP2000263273A - Teaching method and its device for yag laser beam machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically transform vision coordinates to tool coordinates by obtaining reflected measurement light on a workpiece and the vision coordinates of teaching points by means of an image pickup means and automatically performing calibration in the height direction with the focal distance of YAG laser beam and in the front/rear and left/right directions with the YAG laser optical axis. SOLUTION: A semiconductor laser head 37 is fixed on a laser machining head 13 so that a slit beam SB passes through the focal point of a YAG laser beam LB. With a workpiece W irradiated with the slit beam SB, and with the reflected light picked up by a CCD camera 23, the data of a pixel coordinates are obtained. The data are repeatedly obtained by moving the laser machining head 13 downward in the Z direction. A relationship between the Z-axis moving quantity and the pixel coordinate value is determined, and the positioning of the laser machining head 13 is automatically performed. The YAG laser beam LB is radiated to the workpiece W, the bead traces formed by the radiation is picked up, data of the pixel coordinate system of ORG points are obtained and teaching in the X-Y direction is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a teaching method and apparatus for adjusting the focal position of a YAG laser beam to a laser processing point of a work in a YAG laser processing machine for performing three-dimensional laser processing.

[0002]

2. Description of the Related Art Conventionally, at the time of teaching, a mirror is used so that a laser processing point of a work can be photographed coaxially with a YAG laser beam, and the laser processing point of the work reflected by the mirror is imaged by a CCD camera. The captured image is transmitted electrically and displayed on a monitor.

A cross target is provided on the monitor, and the cross target is provided so as to be settable so that the optical axis of the YAG laser beam coincides with the cross target. The laser processing head is moved back and forth and left and right (two-dimensionally on the surface of the work) so that the cross target aligned with the optical axis of the YAG laser light is aligned with the work welding line on the monitor. Thus, teaching is performed so that the optical axis of the YAG laser beam coincides with the welding line of the work.

As a method of adjusting the Z direction (height direction) of the laser processing head, the focus of the CCD camera is adjusted in advance so as to coincide with the focal position of the YAG laser light, and the laser of the actual work is adjusted. To adjust the focal position of the YAG laser beam to the processing point, the position is determined by the position where the CCD camera is in focus.

Other methods of adjusting the height of the laser processing head include a method of detecting the nozzle height and the focal position with an ultrasonic sensor, and a method of detecting the nozzle height and the focal position with a laser displacement sensor.
There are a method of detecting the focal position, a method of detecting the height and the focal position with the nozzle of the capacitance sensor, and a method of detecting the nozzle height and the focal position with the contact type sensor.

When detection is performed by the various sensors described above, the detection result is displayed on a display as vision coordinates by image processing.

Normally, the vision coordinates displayed on the display are two-dimensional data in an XY screen, and the two-dimensional data must be made coincident with the actual coordinates by a teaching point correction system.

[0008]

By the way, in the conventional teaching point correction system, the Z direction (the direction of the nozzle height of the laser processing head) is recognized by the image processing system, and the above vision coordinates and actual coordinates are recognized. It is necessary to perform calibration for matching.

Although the XY plane can be recognized by the image processing system, since the actual scale and the scale of the vision coordinates are different, it is necessary to match them by calibration.

However, if the above-mentioned calibration is performed manually, individual differences among workers may occur,
There was a problem that it hindered automation. Therefore, it is necessary to perform calibration automatically.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to use image pickup means which can normally obtain only two-dimensional data to convert data in a nozzle height direction of a laser processing head into vision coordinates. Acquisition and acquisition of data in the front-rear and left-right directions as vision coordinates using the imaging means, fully automatic calibration to match the vision coordinates in the height direction and the front-rear left-right direction and the actual coordinates, and convert the converted data. It is an object of the present invention to provide a teaching method and an apparatus for a YAG laser processing machine to be prepared.

[0012]

According to a first aspect of the present invention, there is provided a teaching method of a YAG laser processing machine according to the present invention, wherein a YAG laser beam oscillated by a laser oscillator is transmitted through an optical fiber into a laser processing head. In the teaching method of the YAG laser processing machine performed prior to performing the three-dimensional laser processing by irradiating the work from the provided condenser lens, the work is irradiated with the measurement light from the measurement light source head external to the laser processing head. The reflected light of the measurement light on the work is imaged by the imaging means and displayed on a display, and the height-direction calibration of the height-direction vision coordinates of the displayed reflected light and the actual focal position of the YAG laser light is performed. Detecting, accumulating, and data processing are automatically performed in order to perform Display and automatic detection / accumulation / data processing to perform front / rear / left / right calibration of the displayed teaching point front / rear / left / right vision coordinates and the actual YAG laser optical axis. It is characterized in that vision coordinates on the display screen are automatically converted into actual tool coordinates on the laser processing head based on the application data and the front / rear / left / right calibration data.

Therefore, since the data in the direction of the nozzle height of the laser processing head is acquired as the vision coordinates by using the image pickup means which can normally obtain only two-dimensional data, YA
The focus position of the G laser light is easily positioned on, for example, a welding line of the work and teaching is performed. Further, positioning data of, for example, a welding line of the work in the front-rear and left-right directions is acquired as a vision coordinate by using an imaging unit and is taught. Since the calibration to match the above-mentioned height direction and the vision coordinates in the front, rear, left and right directions with the actual coordinates is automatically performed and conversion data is created, teaching in the three-dimensional direction is easily and accurately performed.

According to a second aspect of the present invention, in the teaching method of the YAG laser processing machine according to the first aspect, the teaching point is an irradiation position obtained by irradiating the YAG laser beam. It is characterized by having.

Therefore, the teaching point is YA
By the irradiation position obtained by irradiating G laser light,
Two-dimensional positioning in the front, rear, left and right directions is easily and accurately performed.

According to a third aspect of the present invention, there is provided a teaching device for a YAG laser beam machine according to the present invention.
The work is irradiated with measurement light in a teaching device of a YAG laser processing machine which is performed prior to performing three-dimensional laser processing by irradiating the work with a condensing lens provided in a laser processing head through an optical fiber via an optical fiber. The measuring light source head is provided outside the laser processing head, an image pickup means for picking up reflected light of the measurement light on the workpiece is provided, and a display for displaying an image picked up by the image pickup means is provided. Light vision coordinates and actual YA
Automatically detects, stores, and processes data to perform height calibration with respect to the focal position of the G laser beam. Vision coordinates of the teaching point displayed by imaging the teaching point on the work by the imaging means. The detection, accumulation, and data processing are performed in order to automatically perform the front-rear and left-right calibration of the actual YAG laser optical axis and the actual YAG laser optical axis. And a control device for automatically converting the vision coordinates in the above into the actual tool coordinates in the laser processing head.

Accordingly, since the data in the height direction of the nozzle of the laser processing head is obtained as the vision coordinates by using the image pickup means which can normally obtain only two-dimensional data, the YAG laser is used. The focus position of the light is easily positioned at, for example, a welding line of the work, and teaching is performed. Further, positioning data of, for example, a welding line of the work in the front-rear and left-right directions is acquired as a vision coordinate by using an imaging unit and is taught. Since the calibration to match the above-mentioned height direction and the vision coordinates in the front, rear, left and right directions with the actual coordinates is automatically performed and conversion data is created, teaching in the three-dimensional direction is easily and accurately performed.

According to a fourth aspect of the present invention, there is provided the teaching device for a YAG laser processing machine according to the third aspect, wherein the teaching point is an irradiation position obtained by irradiating a YAG laser beam. It is characterized by having.

Therefore, the operation is the same as that of the first aspect, and since the teaching point is the irradiation position obtained by irradiating the YAG laser beam, two-dimensional positioning in the front-back, left-right direction can be performed easily and accurately. Will be

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a teaching method in laser processing according to the present invention will be described below with reference to the drawings.

Referring to FIG. 12, in a YAG laser beam machine 1 according to the present embodiment, a YAG laser beam LB is oscillated from a laser oscillator 5 provided separately from, for example, a robot controller 3 as a control device. A laser provided at the tip of an arm 11 of a so-called articulated robot, which is a robot 9 which is guided by an optical fiber 7 and can move in a three-dimensional direction of, for example, X, Y, and Z directions as a laser automatic processing machine. It is sent to the processing head 13.

The robot 9 is provided with a boom 17 rotatably in the front-rear direction on an upper part of a robot main body 15 rotatable in a horizontal plane direction on the floor surface. It is provided rotatably in the up-down direction. A laser processing head 13 is provided at the tip of the arm 11 such that the laser processing head 13 can be swung in a horizontal plane direction by a head support arm 19 and is rotatable in a direction orthogonal to the longitudinal direction of the head support arm 19.

The positional relationship between the laser oscillator 5 and the processing point of the laser processing head 13 of the optical fiber 7 is basically free.

The tip of the laser processing head 13 has a YA
A condensing lens (not shown) for condensing the G laser light LB is provided. The YAG laser light LB is emitted from the nozzle 21 provided in the laser processing head 13 toward the work W and Laser processing such as cutting or welding processing is performed on the shape of.

The robot 9 is not limited to the above-mentioned articulated robot, but may be a robot of a rectangular coordinate system in which the arm 11 can move on rectangular coordinates. In this case, the laser processing head 13 is provided on the arm 11 so as to be able to move up and down.

Referring to FIG. 13, the YAG laser beam LB emitted from the tip of the optical fiber 7 is converted into a parallel beam by a collimator lens (not shown) provided in the laser processing head 13, and the parallel beam is collected. It is configured to be condensed by an optical lens. Note that a protective glass (not shown) is provided between the condenser lens and the work W to protect it from spatter and fumes.

The YAG laser light LB condensed by the condensing lens passes through the nozzle 21 provided at the tip of a nozzle holder provided below the laser processing head 13 and irradiates the work W.

An assist gas (shield gas) is supplied into the laser processing head 13, and the assist gas is injected from the nozzle 21 coaxially with the YAG laser beam LB.

In the laser processing head 13, for example, a CCD camera 23 as an image pickup means constituting an image processing system for confirming a welding line on the work W coaxially with the YAG laser beam LB at the time of teaching. Is arranged. In the present embodiment, the rotary bend mirror 25 is configured to rotate in a substantially horizontal plane by a rotary actuator 27 as shown by an arrow in FIG. 13, and the YAG between the collimator lens and the condenser lens described above is provided.
The YAG laser beam LB is provided coaxially with the laser beam LB so as to be able to protrude and retract freely.

As shown in FIG. 12, the CCD camera 23 is connected to, for example, a monitor 33 as a display mounted on the robot 9 via an image processing device 31 constituting an image processing system by a camera signal cable 29. Have been. The image processing device 31 is electrically connected to the robot controller 3 via a communication cable 35.

Accordingly, the welding line on the work W is reflected by the rotating bend mirror 25 and is imaged by the CCD camera 23 via a fixed bend mirror 36 (see FIG. 13) provided below the CCD camera 23, and is imaged. Is displayed on the monitor 33. The monitor 3
On the screen of No. 3, a cross target CT which can be moved and positioned vertically and horizontally is displayed.

Referring to FIG. 13, for example, a semiconductor laser head 37 as a measuring light source head is moved in the same direction as the optical axis of the YAG laser beam LB via a bracket on a head support arm 19 supporting the laser processing head 13. It is provided to be adjustable. The semiconductor laser head 37 has a built-in light-emitting device such as a light-emitting diode that emits semiconductor laser light, and the emitted semiconductor laser light is applied to the work W as slit light SB in this embodiment, The SB is configured to irradiate the work W at an angle of about 50 ° (about 40 ° with respect to the work W) with respect to the optical axis of the YAG laser beam LB.

The semiconductor laser head 37 is attached to a portion that does not affect the processing area as much as possible. At the tip of the semiconductor laser head 37, a condensing lens 39 capable of condensing and adjusting semiconductor laser light is provided. In the present embodiment, the configuration is such that the slit light SB is formed on the work W as reflected light.

The light emitting device in the semiconductor laser head 37 is provided with a volume capable of adjusting the amount of semiconductor laser light, and the semiconductor laser light used in the present embodiment is not particularly limited in wavelength or output. , May be arbitrary.

According to the above configuration, first, the distance between the laser processing head 13 and the work W is set to be the optimum focus position.
For example, the focus position of the YAG laser beam LB is adjusted in advance so as to be located on the surface of the work W. Next, the reflected light of the slit light SB emitted from the semiconductor laser head 37 on the work W is imaged by the CCD camera 23 via the rotating bend mirror 25 and the fixed bed mirror 36, and is passed through the image processing device 31 to the monitor 33. It is displayed together with the work W.

The laser beam processing head 13 and the cross target CT on the monitor 33 are not moved, and the semiconductor laser head 37 is moved so that the center of the slit light SB on the screen of the monitor 33 coincides with the cross target CT on the monitor 33. The slit light SB is moved in the vertical direction (the Z-axis direction in FIG. 13) with respect to the processing head 13.
Are positioned so as to pass through the focal position of the YAG laser beam LB, and the semiconductor laser head 37 is fixed to the laser processing head 13 in this state.

Therefore, when the laser processing head 13 is moved up and down, the slit light SB of the semiconductor laser light moves up and down on the screen of the monitor 33. For example, when the laser processing head 13 is moved upward in the Z direction in FIG. 13, the semiconductor laser head 37 also moves up, so that the slit light SB of the semiconductor laser light travels on the work W to the left in the Y direction in FIG. Since the slit light SB moves, the slit light SB moves downward on the monitor 33 in the present embodiment. Conversely, when the laser processing head 13 is moved downward in the Z direction, the slit light SB on the screen of the monitor 33 moves upward.

That is, since the slit light SB is preset so as to pass through the focal position of the YAG laser light LB, when the slit light SB on the screen of the monitor 33 coincides with the horizontal axis of the cross target CT, the YAG laser light Laser light LB
Is located on the surface of the workpiece W.

Referring to FIG. 12, the image processing device 3
For example, a CPU 41 as a central processing unit in 1 is connected to an input device 43 for inputting data such as laser processing conditions and a processing program, and a display device 45. The input data and teaching points on the work are stored in a CCD. The height direction vision data and front / rear / left / right direction calibration data obtained by comparing the height direction vision coordinates and the front / rear / left / right direction vision coordinates obtained by imaging with the camera 23 with the actual focal position of the YAG laser optical axis. A memory 47 for storing, and a height direction calibration data and a front-rear, left-right calibration data based on an arithmetic expression of a processing program stored in the memory 47, and the laser processing head 13 uses the vision coordinates on the screen of the monitor 33 to read the coordinates. Arithmetic processing unit for converting to actual tool coordinates 49, instruction unit 51 for providing operating instructions to the robot 9 in order to move the laser processing head 13 in order to perform each height direction as well as longitudinal and lateral directions carry shake Deployment of the is connected to the CPU 41. The robot controller 3 controls the robot 9.

The operation of the Z-direction calibration in teaching the work W in the Z-direction will be described below.

Referring to FIG. 1, the rotary actuator 27 shown in FIG.
The CCD is rotated by rotating so that the G laser beam LB advances on the same axis.
An image on the optical axis of the YAG laser beam LB can be captured by the camera 23. The communication port between the robot controller 3 and the image processing system in FIG.
(Step S1).

A semiconductor laser beam ON command is given from the robot controller 3 to confirm that the semiconductor laser beam is ON, and the semiconductor laser head 37 irradiates the work W with the semiconductor laser beam as slit light SB. The slit light SB reflected on the work is rotated by a rotating bend mirror 25.
The image is reflected by the CCD camera 23 via the fixed bend mirror 36, and the image obtained by the CCD camera 23 is displayed on the monitor 33 (steps S2 and S3).

The communication port from the image processing system to the robot controller 3 is opened via the communication cable 35, and the image displayed on the screen of the monitor 33 stores, for example, pixel coordinate data as vision coordinates in the memory of the robot controller 3. (Steps S4 and S4)
5).

Next, the communication port is connected again (step S6).

In order to obtain the robot status of the robot controller 3, one cycle / play mode / command remote servo-on is turned on, and the others are turned off.
Is confirmed (step S7).

The laser processing head 13 is moved downward in the Z direction, and as shown in FIG.
The position of B is moved so as to be located at data Z = + 3 (mm) as the Z-axis movement amount commanded to the robot 9. The robot status of the robot controller 3 is obtained,
The end is repeatedly confirmed until the signal "running" falls. Then, the communication port is opened, and the data of the pixel coordinates of the slit light SB at this time is stored in the memory of the robot controller 3. The pixel coordinate Y at this time is 90. (Steps S8 to S11).

Next, the above-described steps S6 to S11 are repeated, and data Z = + 3 (mm) to data Z = -3 (mm) as shown in FIGS. The data of the pixel coordinates Y is acquired at intervals of 0.2 mm up to and before and stored in the memory (step S12).

When step S12 is completed, the communication port is connected again, and a semiconductor laser light OFF command is given from the robot controller 3 to turn off the semiconductor laser light.
Confirmation of F is made, and the communication port is opened (steps S13 to S16).

The data of the Z-axis movement amount Z and the pixel coordinate value Y instructed to the robot 9 obtained by the image processing as described above are as shown in the table of FIG. It becomes direction calibration data. Note that the Z-direction calibration data is shown in a graph as shown in FIG. 3, and the relational expression between the Z-axis movement amount Z and the pixel coordinate value Y is Z = (Y−240) /50=0.02Y It is represented by -4.8 (step S17).

Therefore, based on the Z-direction calibration data, it is automatically determined how far in the Z direction the focus of the YAG laser light LB is located on the surface of the workpiece W based on the position of the slit light SB of the semiconductor laser light. You can judge it.

Hereinafter, the operation of the XY direction calibration in the XY direction teaching of the work W will be described.

Referring to FIG. 5, step S1 described above is performed.
Similarly, the robot controller 3 is connected to the communication port of the image processing system (step S21).

A semiconductor laser light ON command is given from the robot controller 3 to confirm that the semiconductor laser light is ON, and the work W is irradiated with the slit light SB of the semiconductor laser light from the semiconductor laser head 37. The slit light SB reflected on the work W is reflected by the rotating bend mirror 25 and passes through the fixed bend mirror 36 to the CCD camera 2.
3 and an image obtained by the CCD camera 23 is displayed on the monitor 33 (steps S22 and S23).

The communication port from the image processing system to the robot controller 3 is opened, the image of the slit light SB displayed on the screen of the monitor 33 is processed, and the Z-direction correction amount is determined based on the Z-direction calibration data. Is calculated. (Steps S24 and S25).

Next, the communication port is connected again (step S26).

It is confirmed that one cycle / play mode / command remote servo-on is ON, and that the others are OFF, and the robot status of the robot controller 3 is obtained (step S27).

The robot 9 is instructed to move the laser processing head 13 in the Z direction by the Z direction correction amount calculated in step S25 (step S28).

The robot status of the robot controller 3 is acquired, and the end is repeatedly confirmed until the signal of "operating" is dropped (step S29).

An OFF command for the semiconductor laser light is given from the robot controller 3 to confirm that the semiconductor laser light is OFF. Incidentally, the rotary actuator 27 is operated to rotate the rotating bend mirror 25 so as to retract from the same axis of the YAG laser beam LB (steps S30 to S30).
31).

A program for emitting only one shot of the YAG laser beam LB to form a test bead mark BM on the work W is selected (step S32).

It is confirmed that one cycle / play mode / command remote servo-on is ON, and that the others are OFF, and the robot status of the robot controller 3 is obtained (step S33).

From the nozzle 21 of the laser processing head 13 to Y
The workpiece W is irradiated with only one shot of the AG laser beam LB to form a bead mark BM for a test.
4).

The robot status of the robot controller 3 is acquired, and the end is repeatedly confirmed until the signal of "operating" is dropped (step S35).

The communication port is opened, and the rotating bend mirror 25 is advanced on the optical axis of the YAG laser beam LB.
(A) As shown in FIG.
The center coordinates of M are imaged by the CCD camera 23, and the imaged test bead marks BM are displayed on the monitor 33. Next, data in the pixel coordinate system of the ORG point is obtained (Steps S36 and S37).

Next, the communication port is connected again, and 1
It is confirmed that the cycle / play mode / command remote servo-on is ON and the others are OFF, and the robot status of the robot controller 3 is obtained (steps S38 and S39).

As shown in FIG. 7B, the position of the test bead mark BM is X = −3.0 (mm) (point XX).
The robot 9 is instructed to move the laser processing head 13 in the X direction so that the laser processing head 13 is located at the position. Then, the robot status of the robot controller 3 is obtained, and the end is repeatedly confirmed until the signal of "operating" is dropped, and the communication port is opened (steps S40 to S4).
2).

The center coordinates of the test bead mark BM of X = −3.0 (mm) are imaged by the CCD camera 23 as shown in FIG. 7B, and the imaged bead mark BM is obtained. Is displayed on the monitor 33. Next, data of the pixel coordinate system at the point XX is obtained (step S4).
3).

Next, the communication port is connected again, and 1
It is confirmed that the cycle / play mode / command remote servo-on is ON and the others are OFF, and the robot status of the robot controller 3 is obtained (steps S44 and S45).

The laser processing head 13 is moved in the X and Y directions so that the position of the test bead mark BM is X = + 3.0, Y
= −3.0 (mm) (point X-Y) is given to the robot 9. Then, the robot status of the robot controller 3 is acquired, and the end is repeatedly confirmed until the signal of "operating" is dropped, and the communication port is opened (steps S46 to S48).

X = + 3.0, Y = -3.0 (mm)
The center coordinates of the test bead mark BM at (XY point) are shown in FIG.
As shown in (C), an image is captured by the CCD camera 23, and the captured bead mark BM is displayed on the monitor 33. Next, pixel coordinate system data of the XY point is obtained. The rotary actuator 2 shown in FIG.
7 operates, and the rotating bend mirror 25 moves the YAG laser light L
B is rotated backward from the same axis (step S4).
9).

The data of each of the three points obtained by the image processing as described above is combined, and XY direction calibration data is created as shown in FIG. 7D (step S50). .

The XY direction calibration data is stored in the monitor 33 as shown in FIG.
Since the pixel coordinates are determined in the vision coordinate system (pixel unit) above, the pixel coordinates are different from the actual tool coordinates of the laser processing head 13 in the unit system, and the origin and angle of the coordinate system do not match. For this reason, it is necessary to convert from pixel coordinates (vision coordinates) to actual tool coordinates as shown in FIG.

Hereinafter, a method of converting pixel coordinates (vision coordinates) to tool coordinates will be described in detail.

The pixel coordinates based on the calibration data are different from the tool coordinates in the origin position and the angle as shown in FIG. Each symbol in FIG. 8 is as shown below.

The suffix of the left shoulder indicates the coordinate system.
^P represents pixel coordinates, and ^T represents tool coordinates.

(0,0): Pixel coordinate origin ^P P _TORG : Origin translation vector from pixel coordinate to tool coordinate θ: Rotation angle of origin of tool coordinate with respect to pixel coordinate ( ^P x _ORG , ^P y _ORG ): pixel Tool coordinate origin expressed in coordinate system ( ^P x _XX , ^P y _XX ): Tool coordinate system expressed in pixel coordinate system X axis definition point ( ^P x _XY , ^P y _XY ): Tool coordinate system expressed in pixel coordinate system Y-axis definition point ^P P: Pixel coordinate system movement vector ^T P: Coordinate system movement vector ( ^P x ₁ , ^P y ₁ ): Movement end point expressed in pixel coordinate system ( ^T X ₁ , ^T Y ₁ ): Tool coordinates Referring to FIG. 9, the conversion (magnification) of the unit from the pixel coordinate system to the tool coordinate system will be described based on the above definition.

To obtain the unit conversion (magnification), the distance in pixel units from the tool coordinate origin ( ^P x _ORG , ^P y _ORG ) to the tool coordinate system X axis definition point ( ^P x _XX , ^P y _XX ) What is necessary is just to compare with the distance in mm unit (unit of tool coordinates).

In this case, the distance L in mm unit is L = 3 mm as shown in FIG.
Magnification alpha of the ^{unit, α = 3 / {(P} x XX - P x ORG) 2 + (P y XX - P y ORG) 2}
^1/2 .

[0079] For example, if as shown in FIG. ^{9, α = 3 / {(P} x XX - P x ORG) 2 + (P y XX - P y ORG) 2} 1/2 = 3 / ｛(252− 246) ² + (130−250) ² ｝ ^1/2 = 3 / ｛62 ² + (− 120) ² ｝ ^1/2 = 3 / (14436) ^1/2 = 0.0249688 mm / pixel.

Referring to FIG. 10, the origin rotation angle (θ) of tool coordinates with respect to pixel coordinates will be described based on the definition shown in FIG.

The tool coordinates are rotated around the Z axis with respect to the XY axes of the pixel coordinates. The rotation angle is counterclockwise (C
Next + when CW), when the clockwise (CW) - and since the rotation angle of the tool coordinate origin ^{_{(P x ORG, P y ORG}} ) and tool coordinate system Y-axis defining point ^(P x _XY, ^P y _{X -Y} ).

However, since the origin rotation angle (θ) of the tool coordinates is near −90 °, the solution cannot be specified.
Therefore, it is calculated from the angle (θ0) between the X axis of the pixel coordinates and the Y axis of the tool coordinates. Therefore, θ = θ0−90 °
Becomes

Based on the definition shown in FIG.
_{^{nθ0 = (P y XY - P}} y ORG) / (P x XY - P x ORG) is satisfied. ^{Accordingly, θ0 = tan -1 {(P} y XY - P y ORG) / (P x XY - P x ORG)} θ = tan -1 {(P y XY - P y ORG) / (P x XY - P x _ORG )｝ − 90 °.

[0084] For example, if as shown in FIG. ^{10, θ0 = tan -1 {(P} y XY - P y ORG) / (P x XY - P x ORG)} - 90 ° = tan -1 {(256−250) / (366−246)} − 90 ° = tan ^-1 (0.05) −90 ° = 2.8624 ° −90 ° = −87.13759 °

Referring to FIG. 11, the conversion from the pixel coordinates to the tool coordinates for translation and rotation will be described based on the definition shown in FIG.

[0086] The conversion equation is expressed by _{^{P P = P T R T P}} + P P TORG ......... (1).

Here, ^P P is a pixel coordinate system movement vector and is represented by the following matrix.

[0088]

(Equation 1) The ^P _T R with the rotation matrix is expressed by the following matrix.

(Rotation operator from pixel coordinates to tool coordinates).

[0090]

(Equation 2) ^T P is a tool coordinate system movement vector and is represented by the following matrix.

[0091]

(Equation 3) Equation (1) above defines a 4 × 4 matrix operator and can be represented using a 4 × 1 matrix position vector.

[0092]

(Equation 4) Substituting each matrix into the above equation (2) gives

(Equation 5) Solving the determinant of the above (3) results in the following simultaneous equations.

^P x ₁ = ^T X ₁ cos θ _{^{- T Y 1 sinθ + P x}} ORG ......... (4) and solving for _{^{P y 1 = T X 1 sinθ}} + T Y 1 cosθ + P y ORG ......... (5) T Y 1 the above-mentioned (4),

[Equation 6] ^T Y ₁ sinθ _{^{= T X 1 cosθ- P x 1}} + P x ORG T Y 1 = T X 1 cosθ / sinθ- P x 1 / sinθ + P x ORG / sinθ ......... (6) to (6) (5) to Substituting and solving for ^T X ₁ gives

[Equation 7] ^{_{P y 1 = T X 1 sinθ}} + (T X 1 cosθ / sinθ- P x 1 / sin
_{^{θ + P x ORG / sinθ)}} cosθ + P y ORG = T X 1 sinθ + T X 1 cos 2 θ / sinθ- P x 1 cosθ / sinθ + P x
^{_{ORG cosθ / sinθ + P y ORG}} = T X 1 (sinθ + cos 2 θ / sinθ) - P x 1 cosθ / sinθ + P
^{_{x ORG cosθ / sinθ + P y}} ORG = T X 1 {(sin 2 θ + cos 2 θ) / sinθ} - P x 1 cosθ / sinθ
_{^{+ P x ORG cosθ / sinθ +}} P y ORG here than ^{sin 2 θ + cos 2 θ =} 1 P y 1 = T X 1 / sinθ- P x 1 cosθ / sinθ + P x ORG cosθ / sinθ + P y ORG T X 1 / sinθ _{^{= P x 1 cosθ / sinθ +}} P x ORG cosθ / sinθ + P y 1 - P y ORG T X 1 = P x 1 cosθ- P x ORG cosθ + P y 1 sinθ- P y ORG sinθ ......... (7) (7 Substituting equation (5) into equation (5) and solving ^T Y ₁

[Equation 8] ^{_{P y 1 = (P x 1}} cosθ- P x ORG cosθ + P y 1 sinθ- P y
^{_{ORG sinθ) sinθ + T Y 1}} cosθ + P y ORG = P x 1 cosθ sinθ- P x ORG cosθ sinθ + P y 1 sin 2 θ- P
y _ORG sin ² θ + ^T Y ₁ cos θ + ^P y _ORG ^T Y ₁ cos θ = − ^P x ₁ cos θ sin θ + ^P x _ORG cos θ sin θ− ^P y
₁ sin ² θ + ^P y _ORG sin ² θ + ^P y ₁ − ^P y _ORG ^T Y ₁ = − ^P x ₁ sin θ + ^P x _ORG sin θ − ^P y ₁ sin ² θ / cos θ + ^P y
^{_{ORG sin 2 θ / cosθ + P}} y 1 / cosθ- P y ORG / cosθ T Y 1 = - P x 1 sinθ + P x ORG sinθ- P y 1 (sin 2 θ-1 / cos
θ) + ^P y _ORG (sin ² θ−1 / cos θ) where sin ² θ−1 = −cos ² θ and ^T Y ₁ = ^−P x ₁ sin θ + ^P x _ORG sin θ− ^P y ₁ (−cos ² θ _{^{/ cosθ) + P y ORG (}} -cos 2 θ / c osθ) = - P x 1 sinθ + P x ORG sinθ + P y 1 cosθ- P y ORG cosθ ......... (8) (7) and formula (8) Is multiplied by -1 because the value obtained from is the value from the origin and actually needs the value to the origin.

[0094]

[Equation 9] _{^{T X 1 = - (P x}} 1 cosθ- P x ORG cosθ + P y 1 sinθ- P y ORG sinθ) = - P x 1 cosθ + P x ORG cosθ- P y 1 sinθ + P y ORG sinθ ...... _{^{... (9) T Y 1 =}} - (- P x 1 sinθ + P x ORG sinθ + P y 1 cosθ- P y ORG cosθ) = P x 1 sinθ- P x ORG sinθ- P y 1 cosθ + P y ORG cosθ ...... ... (10) for example, if as shown in Figure 11, ^T X ₁ is X component of the tool coordinate system moving vector ^T P, ^T Y ₁ is a Y component of the tool coordinate system moving vector ^T P, ^P x ₁ is the X component of the pixel coordinate system detection point, ^P x ₁ = 372, ^P y ₁ is the Y component of the pixel coordinate system detection point, ^P y ₁ = 136, and ^P x _ORG is the tool coordinate system in the pixel coordinate system. origin X ^P x _ORG = 246 in component, ^P y _ORG is ^P y _ORG = 250 in the tool coordinate system origin Y component in the pixel coordinate system, the theta rotation movement angle θ = -87.13759 ° origin, is,
Is substituted into the above-mentioned (9) ^T X ₁ = -120.1499164 are substituted into the above-mentioned (10) ^T Y ₁ = -120.1498964 ^T X ₁ obtained here, ^T Y ₁ is pixels.

When multiplied by the conversion magnification α of the unit obtained as described above, α = 0.0249688 mm / pixel ^T X ₁ = 0.0249688 × (−120.1499164) = − 2.999999233 mm ^T Y ₁ = 0.0249688 × (−120.1498964) = − 2.999998733 from the above mm, when obtaining the carburetion data, tool coordinate system origin _{^{(P x ORG, P y ORG}} ) and the tool coordinate system Y-axis defining point _{^{(P x XY, P y XY}} ) and tool coordinate Since the magnification α is calculated from three data with the system X axis definition point ( ^P x _XX , ^P y _XX ), it can be calculated and fixed at the time of carburetion.

[0096] Further, when obtaining the carburetion data, tool coordinate system origin ^{_{(P x ORG, P y ORG}} ) and the tool coordinate system Y-axis defining point ^{_{(P x XY, P y XY}} ) and the tool coordinate system X
Since the origin rotation movement angle θ is calculated from three data with the axis definition points ( ^P x _XX , ^P y _XX ), it can be calculated and fixed at the time of carburetion.

[0097] Further, upon detecting the respective detection points, the tool coordinate system origin ^{_{(P x ORG, P y ORG}} ) were fixed after carburetion, pixel coordinate system detection point ^{_{(P x 1, P y 1}} ) detected Fluctuates before, the origin rotation movement angle θ is fixed after carburetion,
The magnification α is fixed after carburetion, and the tool coordinate system movement vector ^T P ( ^T X ₁ , ^T Y ₁ ) is calculated from the above four data.

From the above, after the laser processing head 13 is actually moved to the teaching point, the processing is performed as follows.

The amount of correction in the Z direction to the coordinate center is automatically calculated as ± based on the position of the slit light SB, and the laser processing head 13 is moved up and down by the amount of Z direction correction. Reference numeral 13 denotes a position of the optimum focal height of the YAG laser beam LB.

Further, the welding line is found, and the amount of correction in the XY direction to the coordinate center is automatically calculated by the above-described formula.
Is moved in the front-rear and left-right directions (X-Y directions), so that the welding line coincides with the center of the YAG laser beam LB.

The above process is fully automatic, and the teaching process in the three-dimensional directions of the X, Y, and Z axes for positioning the focal position of the YAG laser beam LB on the welding line of the workpiece W is easily performed. Will be

The present invention is not limited to the above-described embodiment, but can be embodied in other forms by making appropriate changes.

[0103]

As will be understood from the above description of the embodiments of the present invention, according to the first aspect of the present invention, the nozzle height of the laser processing head can be increased by using the imaging means which can normally obtain only two-dimensional data. Since the data in the vertical direction can be acquired as the vision coordinates, the focus position of the YAG laser beam can be easily positioned on, for example, a welding line of the work, and teaching can be performed. Further, the positioning data of, for example, a welding line of the work in the front-rear and left-right directions can be acquired as teaching coordinates using an image pickup means and teaching can be performed. Therefore, it is possible to automatically perform calibration to match the above-described height direction and the vision coordinates in the front, rear, left, and right directions with the actual coordinates to create conversion data, so that three-dimensional teaching can be performed easily and accurately. Can be.

According to the second aspect of the present invention, the teaching point is irradiated with a YAG laser beam to form an irradiation position such as a laser mark, so that two-dimensional positioning in the front-rear, left-right direction can be performed easily and accurately. Can be.

According to the third aspect of the present invention, the effect is the same as that of the first aspect, and the data in the direction of the nozzle height of the laser processing head is used as the vision coordinates by using the imaging means that can normally obtain only two-dimensional data. Since it can be acquired, teaching can be easily performed by positioning the focal position of the YAG laser beam at, for example, a welding line of the work. Further, the positioning data of, for example, a welding line of the work in the front-rear and left-right directions can be acquired as teaching coordinates using an image pickup means and teaching can be performed. Therefore, it is possible to automatically perform calibration to match the above-described height direction and the vision coordinates in the front, rear, left, and right directions with the actual coordinates to create conversion data, so that three-dimensional teaching can be performed easily and accurately. Can be.

According to the fourth aspect of the present invention, the same effect as in the second aspect is achieved. By irradiating a teaching point with a YAG laser beam to form an irradiation position of a laser mark or the like, two points in the front-rear and left-right directions can be obtained. Dimensional positioning can be performed easily and accurately.

[Brief description of the drawings]

FIG. 1, showing an embodiment of the present invention, is a flowchart of Z-axis calibration communication.

FIGS. 2A to 2Z are schematic diagrams showing image data of Z-axis calibration. FIGS.

FIG. 3 is a graph showing an embodiment of the present invention and showing a relationship between a Z-axis movement amount Z and a pixel coordinate value Y;

FIG. 4 shows an embodiment of the present invention, and is a data table of a Z-axis movement amount Z and a pixel coordinate value Y.

FIG. 5 shows an embodiment of the present invention and is a flowchart of XY axis calibration communication.

FIG. 6 is a flowchart continued from FIG. 5;

FIG. 7 illustrates an embodiment of the present invention, and is an explanatory diagram for converting XY axis calibration data displayed on a monitor from vision coordinates to tool coordinates.

FIG. 8 illustrates an embodiment of the present invention, and is an explanatory diagram of a method of converting pixel coordinates to tool coordinates.

FIG. 9 illustrates an embodiment of the present invention, and is an explanatory diagram of a method of converting units from pixel coordinates to tool coordinates.

FIG. 10 illustrates an embodiment of the present invention, and is an explanatory diagram of an origin rotation movement angle of tool coordinates with respect to pixel coordinates.

FIG. 11 shows an embodiment of the present invention, and is an explanatory diagram of a method of converting translation and rotation from pixel coordinates to tool coordinates.

FIG. 12 is an overall view of a YAG laser processing machine according to an embodiment of the present invention.

FIG. 13 shows an embodiment of the present invention, and is a perspective view of a laser processing head.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 YAG laser processing machine 3 robot controller (control device) 5 laser oscillator 9 robot (laser automatic processing machine) 13 laser processing head 23 CCD camera (imaging means) 31 image processing device (image processing system) 33 monitor (display) 37 Semiconductor laser head (measurement light source head) LB YAG laser light SB slit light BM Bead mark CT Cross target

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4E068 CA06 CA09 CA10 CA11 CB02 CB04 CB09 CC02 CD15 CE02 CE06 CE08 5H269 AB11 AB12 AB33 BB03 BB09 CC09 DD05 FF02 FF05 GG08 JJ09 JJ20 KK03 NN18 SA08 SA12 SA29 9A001 BB02 BB02BB03 HH05 HH19 HH24 HH29 HH34 JJ49 KK37 KK54 KZ16 KZ32

Claims (4)

[Claims] 1. A teaching of a YAG laser processing machine performed prior to performing a three-dimensional laser processing by irradiating a work with a YAG laser beam oscillated by a laser oscillator through an optical fiber from a condenser lens provided in a laser processing head. In the method, the work is irradiated with measuring light from a measuring light source head external to the laser processing head, reflected light of the measuring light on the work is imaged by an imaging means, displayed on a display, and the displayed reflected light is displayed. Automatically detects, accumulates, and processes data in the height direction to calibrate the height direction vision coordinates and the actual focus position of the YAG laser light, and captures the teaching point on the work with the imaging means. And the display coordinates of the displayed teaching point in the front-rear and left-right directions and the actual YA
Automatically performs detection, accumulation, and data processing to perform front-rear and left-right calibration with the G laser optical axis. Vision coordinates on the display screen are obtained using the height calibration data and the front-rear and left-right calibration data. Characterized in that YAG automatically converts the coordinates into actual tool coordinates in a laser processing head
Teaching method of laser processing machine. 2. A teaching method for a YAG laser processing machine according to claim 1, wherein the teaching point is an irradiation position obtained by irradiating a YAG laser beam. 3. A teaching of a YAG laser processing machine which is performed prior to performing a three-dimensional laser processing by irradiating a work with a YAG laser beam oscillated by a laser oscillator through an optical fiber from a condenser lens provided in a laser processing head. In the apparatus, a measuring light source head for irradiating the work with the measuring light is provided outside the laser processing head, and an imaging means for imaging the reflected light of the measuring light on the work is provided, and an image taken by the imaging means is displayed. A display is provided to automatically detect, accumulate and process data in order to calibrate height coordinates between the displayed vision coordinates of the reflected light and the actual focal position of the YAG laser light, and to provide a teaching point on the work. Between the vision coordinates of the teaching point imaged and displayed by the imaging means and the actual YAG laser optical axis. Performs detection, accumulation, and data processing to automatically perform front-rear, left-right calibration, and uses the height calibration data and front-rear, left-right calibration data to calculate the actual coordinates of the laser processing head from the vision coordinates on the display screen. A teaching device for a YAG laser beam machine, comprising a control device for automatically converting the tool coordinates into the tool coordinates. 4. The teaching device for a YAG laser processing machine according to claim 3, wherein the teaching point is an irradiation position obtained by irradiating a YAG laser beam.