JPH05138354A - Automatic welding profiling device - Google Patents

Abstract

PURPOSE:To accurately control weld line profiling and to obtain high quality welding by detecting and controlling a state of a weld zone in a real time by an ITV camera and a laser slit light emitting part. CONSTITUTION:In a welding machine controller 10, weld zone visual information 8 photographed by the ITV camera 1 after arc starting is sent to a picture processor 9. In the picture processor 9, GL1, GR1 and BL are obtained from a light cutting line of laser slit light 17 from this picture and coordinates of the torch present position TC are obtained from other pieces of visual information. X coordinates of the welding torch target position XC are then obtained based on a bead contact point BL. The deviation quantity DELTAX=XC-TC between the torch present position TC and the welding torch target position XC is calculated from the above. The controller 10 moves the torch 4 on the X axis by this obtained DELTAX. Further, automatic control is continued by fetching next picture information and repeating the same control. This is repeated till welding is completed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic welding copying apparatus.

[0002]

2. Description of the Related Art In the control of welding line copying, as shown in FIG.
V) One using the camera 1 or one using the laser displacement sensor 17S as shown in FIG. In the former one using the ITV camera 1 shown in FIG. 6, the image information indicated by the welded portion visual information 8 obtained from the ITV camera 1 is processed by the image processing device 9, and the groove left and right end positions GL1, GR1 and the torch position are obtained. (Wire position) TC,
The front bead shape BL and the like are obtained and input to the welding machine control device 10, and the welding carriage 3, the welding torch 4, and the welding wire 5 are controlled to perform the welding line copying control. In addition, here ITV
An infrared camera may be used instead of the camera 1.

A laser displacement sensor 17S shown in FIG.
In the one using, the laser displacement sensor 17S is traversed over the groove to the left or right, or the inside of the groove is sensed using a rotating mirror, and the inside shape 18 of the groove is input,
By the shape detection processing device 19, the groove left and right end positions GL2,
GR2, bead inflection point position BL, etc. are detected, the welding machine control device 10 controls the welding carriage 3, the welding torch 4, the welding wire 5 or the welding electrode, and the copying control of the welding line (bead contact) is performed. ..

[0004]

However, in the system using the ITV camera 1 shown in FIG.
Of these, the groove left and right ends GL1 and GR1 and the welding wire 5 tip TC shown in FIG. 6 (electrode tip position in TIG welding)
Is recognized with a fairly high degree of accuracy, but it is not easy to find the front bead ends BL1 and BR1 and the bead contact point BL (the joint between the bead and the bead) which are difficult to discriminate on the image.

For this reason, the control of positioning the welding torch 4 at the center of the groove surface 7 as a result of the image processing becomes confused by a certain percentage, and when a multi-pass multi-layer welding as shown in FIG. 8 is performed. Wants to find the front bead contacts (left and right) BL1 and BR1 and position the welding torch 4 at the center thereof as shown in FIG.
It was very difficult to obtain from, and it was difficult to control the multi-pass multi-layer pile.

When relying on the laser displacement sensor 17S, the groove left and right ends GL2 and GR2 and the front bead end BL are also included.
Although the bead contact can be obtained, the position of the welding wire 5 (or electrode) cannot be recognized, so the welding wire 5 (or electrode) must be controlled as a relative deviation from the initially set position. Even if there was a displacement due to the backlash of the welding carriage 3, this could not be fed back. Further, in the case of the laser displacement sensor 17S, a mechanism such as a rotating mirror and a weaving device for scanning the inside of the groove is required, and the device is large.

When the laser displacement sensor 17S and the ITV camera 1 are used together, the groove shape (groove left and right ends GL2, GR2) and IT obtained from the laser displacement sensor 17S are used.
The groove shape obtained from the V camera 1 (the left and right edges of the groove BL1, B
It is necessary to convert R1) to the same coordinate unit system,
At this time, the left and right edges BL of the groove obtained from the ITV camera 1
1 and BR1 include an error, and highly accurate copying control cannot be performed.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic welding copying apparatus capable of performing high-precision copying control in a multi-layer build-up control without making the apparatus large in view of the above problems.

[0009]

SUMMARY OF THE INVENTION The present invention for achieving the above object is directed to a laser slit light emitting section for obtaining a light cutting image in a groove in front of the welding torch in the traveling direction, and a laser slit light emitting section for advancing from the laser slit light emitting section. IT for detecting the welding information including the above-mentioned welding torch and the molten pool including the light section image in the front direction
It is characterized by having a V camera and means for calculating a groove shape by welding information of the ITV camera and calculating a welding wire position or an electrode position.

[0010]

The optical cutting image (light cutting line) by the laser slit light appears in one image information by the ITV camera, and the visual information in the welded portion and the laser slit light bent and reflected in the groove. The amount of misalignment of the torch is detected from the internal shape of the groove obtained from the cutting line, and the torch position can be controlled.

[0011]

Embodiments of the present invention will now be described with reference to FIGS. In FIG. 1, the welding carriage 3 (or the tip of the welding robot) that moves along the groove surface 7 (along the welding direction Y) is provided with a welding torch 4 and a welding wire 5, and this welding wire 5 is provided with a laser slit light emitting portion 2 in front of the traveling direction of the ITV camera 1.
Is provided.

Of these, in the laser slit light emitting section 2, the laser slit light 17 is irradiated toward the groove to obtain a light section image (light section line) of the groove surface welded section. That is, the optical cutting lines GL1, BL, GR1 are obtained in the welding portion visual information 8 by the ITV camera 1 shown in FIGS. 1 and 3. Further, the ITV camera 1 obtains the above-mentioned optical cutting line, the welding wire 5 (welding torch 4), and the groove surface 7 as the welding portion visual information 8.

In the image processing device 9 and the welding machine control device 10, welding adaptive control is performed in which the visual information 8 of the welded portion is image-processed and the position of the welding wire (welding torch 4) with respect to the groove surface 7 of the workpiece 6 is controlled. Be done.

In the image processing apparatus 9, as shown in FIG. 4, first, from the light cutting line projected from the laser slit light emitting section 2,
The bent position is detected, and the left and right ends of the groove GL1, GR1 are detected.
And the bead contact BL. Further, from this, the welding torch target position XC is obtained. The torch shift amount ΔX is calculated from these information, and the torch horizontal position control (X-axis control 1
Perform 1). Also, the bead height is calculated from the light cutting line in the groove, and the lower end position of the torch is controlled (Z-axis control 13).
However, it is also possible to control the arc length. Further, as shown in FIG. 5, for example, a welding cross-sectional area A is obtained by trapezoidal approximation from the intersection points BL1 and BR1 of the groove surface 7 and the bead, the bead contact point BL, and the intersection point BA of the bead maximum peak height BL1 and the groove.
The speed of the welding carriage can be controlled (V∝A, and Y-axis control 12 is performed) depending on the size of.

Next, the flow chart of the welding machine control device shown in FIG. 2 will be described from the visual information of the welded portion by the ITV camera 1 shown in FIG. 3 and the relationship diagram between the groove cross-sectional shape and the welding torch shown in FIG. In FIG. 2, the welding machine control device 10 is
After the arc start, the visual information of the welded portion photographed by the ITV camera 1 is sent to the image processing device 9. In the image processing device 9, GL1, GR1, BL are obtained from the light cutting line of the laser slit light 17 from this image, and the coordinates of the torch current position TC are obtained from other visual information. Next, the X coordinate of the welding torch aiming position XC is obtained based on the bead contact point BL. From the above, the deviation amount ΔX = XC−TC between the torch current position TC and the welding torch target position XC is calculated.
The control device 10 moves the torch 4 on the X axis by the calculated ΔX. Further, automatic control is continued by fetching the next image information and repeating the same control. This will be repeated until the welding is completed.

[0016]

According to the welding automatic copying apparatus of the present invention described above, the state of the welding portion is detected and controlled in real time by the ITV camera and the laser slit light emitting portion.
It reacts properly to the deformation of the welded part and the backlash of the trolley, so that the welding line tracing control can be performed accurately, and the welding conditions corresponding to the bead shape can be fed back to provide higher quality welding. it can.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an automatic welding copying apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart of the control device of this embodiment.

FIG. 3 is an explanatory diagram of visual information by the ITV camera of this embodiment.

FIG. 4 is an explanatory view showing a relationship between a groove cross-sectional shape and a welding torch.

FIG. 5 is an explanatory view showing a groove cross-sectional shape and a build-up cross-sectional area.

FIG. 6 is a perspective view showing a control method by a conventional ITV camera.

FIG. 7 is a perspective view showing a control method using a conventional laser displacement sensor.

FIG. 8 is a cross-sectional view of the stacking sequence of welding.

FIG. 9 is a cross-sectional view of the stacking sequence of welding.

[Explanation of symbols]

 1 ITV camera 2 Laser slit light emitting part 3 Welding trolley 4 Welding torch 5 Welding wire 6 Workpiece 7 Groove face 8 Weld visual information 9 Image processing device 10 Welding machine control device 11 X axis control 12 Y axis control 13 Z Axis control 14 Welding direction 15 Front bead 16 Rear bead 17 Laser slit light 18 Internal groove shape 19 Shape detection processing device

Claims (1)

[Claims] 1. A laser slit light emitting portion for obtaining an optical cutting image in a groove in front of a welding torch in a traveling direction, and a welding torch and a light cutting image located in front of the laser slit light emitting portion in a traveling direction. An automatic welding copying apparatus comprising: an ITV camera for detecting welding information including a molten pool; and means for calculating a groove shape by the welding information of the ITV camera to calculate a welding wire position or an electrode position.