JP2000210771A - Automatic copying controller for welding position and welding method for groove parts of members to be welded - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain high quality beads with a simple and compact structure by detecting at least one side boundary part of a part which is not placed upon the welding pool picture and the arc picture of a welding electrode picture photographed by a two-dimensional light receiving means, and calculating a deviation in a position. SOLUTION: The type drawing of the detected information of the deviation in a position of a TV monitor, shows the profile lines of an arc picture, a welding pool picture and an electrode picture. By detecting the left and the right boundary positions on plural horizontal lines in an electrode window (detecting area) W1, and by a calculation from their average value, an electrode center position M1 (Xm1, Ym1) is found as its midpoint. With respect to melting pool windows W2 and W3, a melting pool center position M2 (Xm2, Ym2) is found as its midpoint by a calculation from the average value of boundary positions detected on the plural horizontal lines. By setting a difference in the electrode center position M1 to the melting pool center position M2 as the deviation quantity in a position of an electrode, and by converting it into an actual deviation quantity, the copying control of the electrode is performed according to a converted deviation quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding position automatic profiling control device and a method for welding a groove of a member to be welded, and more particularly to an automatic welding position for welding a groove of a member to be welded using a non-consumable welding electrode. The present invention relates to a profile control device and a method suitable for a method for welding a groove of a member to be welded.

[0002]

2. Description of the Related Art As a conventional automatic copying control apparatus of this kind of a welding apparatus, one disclosed in Japanese Patent Application Laid-Open No. 8-150475 is known. That is, a wire of the welding torch, the lower end of which is movably arranged facing the groove surface, a device for driving the welding wire, and a control device for controlling the driving device,
A CCD camera arranged so as to be movable in a forward direction of welding in a welding torch and imaging a weld portion;
Using the image captured by the camera, the welding wire insertion position,
There is known a device including a device for grasping the positions of the left end of the bead and the right end of the bead, and controlling the welding line so that the wire insertion position is located at the center between the positions of the left end of the bead and the right end of the bead.

[0003]

However, according to such a conventional welding position automatic profiling control device, since the insertion position of the welding wire whose tip position changes variously due to the welding arc heat is grasped, the welding wire is controlled. It was difficult to extract the positional deviation between the tip and the welding target part with high accuracy, and a high-quality weld bead could not be obtained. In addition, the left and right ends of the weld bead in front of the weld pool in the welding arc are grasped as the welding target part. Since the position of the welding target portion does not match and is shifted, it is difficult to prevent the positional deviation between the welding wire and the welding target portion with high accuracy, and it was not possible to obtain a high-quality weld bead. .

An object of the present invention is to provide a welding position automatic profiling control device and a groove welding method for a member to be welded, which can obtain a high-quality welding bead with a simple and compact structure.

[0005]

A first feature of the present invention to achieve the above object is to provide a non-consumable welding electrode in which a tip portion is movably disposed opposite a groove of a member to be welded. An electrode position control mechanism that drives the welding electrode, an electrode position control device that controls the movement of the welding electrode by the electrode position control device, and a welding line direction front of the welding electrode that is movably disposed; A two-dimensional light receiving unit that captures an image of the vicinity of an arc generating portion generated between the electrode and the member to be welded; and an electrode position control device that calculates a displacement of the welding electrode from an image captured by the two-dimensional light receiving unit. And a position deviation control device for controlling the welding position, wherein the position deviation control device does not overlap with the welding pool image and the arc image of the welding electrode image captured by the two-dimensional light receiving means. Detecting at least one side boundary portion of the minute in that a configuration to calculate a positional deviation.

A second feature of the present invention is that a non-consumable welding electrode whose tip is movably arranged facing a groove of a member to be welded, an electrode position control mechanism for driving the welding electrode, An electrode position control device that controls the movement of the welding electrode by an electrode position control device; and an arc generation that is disposed movably forward in a welding line direction of the welding electrode and that is generated between the welding electrode and a member to be welded. A welding position comprising: a two-dimensional light receiving unit that captures an image of the vicinity of the unit; and a displacement control device that calculates a displacement of the welding electrode from the image captured by the two-dimensional light receiving device and controls the electrode position control device. In the automatic copying control device, the displacement control device is configured to calculate a displacement by detecting at least one boundary portion of the weld pool image captured by the two-dimensional light receiving unit.

A third feature of the present invention is that a non-consumable welding electrode whose tip is movably disposed facing a groove of a member to be welded, an electrode position control mechanism for driving the welding electrode, An electrode position control device that controls the movement of the welding electrode by an electrode position control device; and an arc generation that is disposed movably forward in a welding line direction of the welding electrode and that is generated between the welding electrode and a member to be welded. A welding position comprising: a two-dimensional light receiving unit that captures an image of the vicinity of the unit; and a displacement control device that calculates a displacement of the welding electrode from the image captured by the two-dimensional light receiving device and controls the electrode position control device. In the automatic scanning control device, the displacement control device calculates a displacement by detecting a plurality of locations on at least one boundary portion of a welding electrode image or a welding pool image captured by the two-dimensional light receiving unit. It lies in the fact that was formed.

A fourth feature of the present invention is that a non-consumable welding electrode whose tip is movably disposed facing a groove of a member to be welded, an electrode position control mechanism for driving the welding electrode, An electrode position control device that controls the movement of the welding electrode by an electrode position control device; and an arc generation that is disposed movably forward in a welding line direction of the welding electrode and that is generated between the welding electrode and a member to be welded. A welding position comprising: a two-dimensional light receiving unit that captures an image of the vicinity of the unit; and a displacement control device that calculates a displacement of the welding electrode from the image captured by the two-dimensional light receiving device and controls the electrode position control device. In the automatic scanning control device, the position shift control device detects at least one boundary portion of a portion that does not overlap with the welding pool image and the arc image of the welding electrode image captured by the two-dimensional light receiving unit, In that a configuration to calculate a positional deviation detecting at least one boundary of the weld pool image captured by the two-dimensional light-receiving means.

According to a fifth feature of the present invention, there is provided a non-consumable welding electrode having a tip portion movably disposed opposite a groove of a member to be welded, an electrode position control mechanism for driving the welding electrode, An electrode position control device that controls the movement of the welding electrode by an electrode position control device; and an arc generation that is disposed movably forward in a welding line direction of the welding electrode and that is generated between the welding electrode and a member to be welded. A welding position comprising: a two-dimensional light receiving unit that captures an image of the vicinity of the unit; and a displacement control device that calculates a displacement of the welding electrode from the image captured by the two-dimensional light receiving device and controls the electrode position control device. In the automatic scanning control device, the position shift control device is configured to reduce a plurality of portions of at least one boundary portion of a portion that does not overlap with the welding pool image and the arc image of the welding electrode image captured by the two-dimensional light receiving unit. Out, and in that a configuration to calculate a positional deviation by detecting a plurality of locations of at least one side boundary of the weld pool image captured by the two-dimensional light-receiving means.

A sixth feature of the present invention is that a non-consumable welding electrode in the form of a rod having a pointed tip which is movably arranged with the tip opposed to the groove of the member to be welded, an X traveling cart, and a Y traveling. A trolley and a Z traveling trolley, wherein the welding electrodes are connected to the X axis, the Y axis and the Z
An electrode position control mechanism that can be driven in the axial direction, an electrode position control device that controls driving of the welding electrode by the electrode position control device, an interference filter, and an industrial television, and a welding line direction front of the welding electrode. And a two-dimensional light receiving means for imaging the vicinity of an arc generating portion generated between the welding electrode and the member to be welded, and a bright part from a dark part in the image captured by the two-dimensional light receiving means. An image processing apparatus for calculating a position shift of the welding electrode having a differential or smoothing differential processing unit for extracting a maximum point or a minimum point at an edge part changing to a part or an edge part changing from a bright part to a dark part; A welding position control apparatus that controls the electrode position control device so as to correct the position shift of the welding electrode based on the position shift information calculated by the image processing device. In the automatic scanning control device, the image processing device may include a welding pool image in the welding electrode image captured by the two-dimensional light receiving unit and a plurality of portions of at least one side boundary portion or both side boundary portions of the rod-shaped main body portion that does not overlap with the arc image. Extraction of the maximum point or the minimum point detected by the differentiation or smoothing differentiation processing unit, and a plurality of at least one side boundary part of the weld pool image captured by the two-dimensional light receiving means and at least one side boundary part of the groove shoulder image. The configuration is such that a position is detected by a differentiation or smoothing differentiation processing unit, a local maximum point or a local minimum point is extracted, and a positional shift between the two is calculated.

A seventh feature of the present invention is that an end of a non-consumable welding electrode is disposed opposite to a groove of a member to be welded, and an arc is provided between the welding electrode and the groove of the member to be welded. Generating a welding pool and driving in the direction of the welding line, and two-dimensional light receiving means in the vicinity of the arc generating portion generated between the welding electrode and the member to be welded from the front in the welding line direction of the welding electrode. In the method for welding a groove of a member to be welded, the position of the welding electrode is calculated from the image taken by the two-dimensional light receiving means, and the position of the welding electrode is corrected and controlled to be welded. Detecting at least one boundary portion of a portion of the welding electrode image captured by the two-dimensional light receiving unit that does not overlap with the welding pool image and the arc image to calculate a displacement, and correcting the displacement of the welding electrode based on the calculated displacement; Configuration Lies in that it has.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a schematic configuration diagram of a welding position automatic scanning control device according to the present invention. In FIG. 1, reference numeral 1 denotes a non-consumable welding electrode such as a tungsten electrode (hereinafter abbreviated as a welding electrode).
The tip has a sharp rod shape. Reference numerals 2 and 3 are members to be welded, 4 is a welding groove (hereinafter, a groove including a welding bead is referred to as a groove), 5 is an arc generating portion at the electrode tip, and 6 is a light receiving means. The light receiving means 6 includes an interference filter 7 and a two-dimensional light receiving camera 8 such as an industrial television (ITV). The light receiving means 6 is disposed in front of the welding progress direction,
The molten pool and the electrode 1 are observed (imaged) from diagonally forward of the groove 4. A control circuit 9 for the two-dimensional light receiving camera 8 outputs an analog video (image) signal to the outside.

Reference numeral 15 denotes an electrode position control mechanism. The electrode position control mechanism 15 includes an X traveling axis 16, an X traveling vehicle 17 traveling on the X traveling axis, a Z traveling axis 20 integrally provided on the X traveling vehicle 17, and traveling on the Z traveling axis. The vehicle has a Z traveling vehicle 21, a Y traveling shaft 18 provided integrally with the Z traveling vehicle 21, and a Y traveling vehicle 19 traveling on the Y traveling axis.

The welding electrode 1 and the light receiving means 6 are provided on the Y traveling carriage 1
9, and by driving the electrode position control mechanism 15, the welding line direction (X
Direction), the direction orthogonal to the welding line (Y direction), and the vertical direction (Z
Direction).

Reference numeral 10 denotes an image processing device. The image processing apparatus 10 includes an image input unit that A / D converts an analog image signal output from the light receiving unit control circuit 9 into a digital amount and inputs multi-valued image data, and a multi-valued image that stores the multi-valued image data. A storage unit, and a maximum point or a minimum at an edge portion that changes from a dark portion to a bright portion in the image or an edge portion that changes from a bright portion to a dark portion in the image from the multi-valued image data stored in the multi-valued image storage unit. A differential or smoothing differential processing unit for extracting a point, and detecting a boundary position from the maximum point and minimum point data, and detecting a predetermined electrode center position, a molten pool center position, and an electrode center position shift with respect to the molten pool center position from the boundary position detection. It has an arithmetic processing section for detecting, a main control section for controlling these overall. Reference numeral 11 denotes a TV monitor which displays an output video signal from the light receiving means control device 9 and outputs and displays a processing result from the image processing device.

Reference numeral 13 denotes an electrode position control device for driving and controlling the electrode position control mechanism 15, and reference numeral 14 denotes a welding power source. 12 is
The overall control device controls the image processing device 10, the electrode position control device 13, and the welding power source 14 in an integrated manner, and includes a personal computer or the like. Overall control device 12
Has a function of storing in advance a target scanning position of an electrode in each welding pass with respect to a member to be welded for performing multi-pass welding, and a welding electrode based on the electrode position and electrode position shift information obtained from the image processing apparatus 12. And a welding line tracing control function of outputting the movement amount of No. 1 to the electrode position control device 13. Further, the overall control device 12 stores a groove reference shape such as a groove depth, a groove angle, a step difference, and the like, such as a number of welding passes, a reference welding current, a voltage, a welding speed, and a wire feeding speed for each pass. The welding plan data and the like can be stored, and these data can be corrected before starting welding or before starting welding in each welding pass. The image processing device 10 and the overall control device 12 constitute a displacement control device that calculates the displacement of the welding electrode from the image captured by the two-dimensional light receiving means and controls the electrode position control device.

FIG. 2 is a schematic view of a molten pool and an electrode image portion taken by the two-dimensional light receiving means of FIG. Contrary to a normal image, black and white are inverted, that is, bright (high luminance) parts are expressed as black, and dark (low luminance) parts are expressed as white. In FIG. 1, 1 is an image of a welding electrode, 23 is an image of a molten pool, 24 is an arc image, 29
And 30 are groove walls. In addition, 2a and 3a are boundary lines between the groove bottom and the groove slope in the groove walls 29 and 30,
Reference numerals 2b and 3b denote boundary lines between the groove slopes on the groove walls 29 and 30, and the groove surface. Normally, the arc image 24 is the brightest, and the molten pool image 23 and the electrode image 1 are picked up as bright images in this order. The groove walls 29 and 30 are also brightly imaged by the arc light 24 during welding.
When the gap (bottom width) at the groove bottom is narrow, the molten pool 2
Numeral 3 is regulated by the width of the groove bottom and extends in the welding line direction. In other words, the width of the molten pool 23 in the direction orthogonal to the welding line is the gap (bottom width) at the groove bottom. Also,
The tip 1a of the electrode 1 is not captured as a clear image due to the influence of the strong arc light.

FIG. 3 schematically shows positional deviation detection information for performing automatic welding copying in the present invention based on the image of FIG. In FIG. 3, only the contour lines are shown for the arc image, the molten pool image, and the electrode image. In the detection of the electrode position shift in the present invention, first, the center M1 of the electrode image 1 is detected, then the center M2 of the molten pool image 23 is detected, and the center M2 of the molten pool image 23 and the center M1 of the electrode image 1 are detected. Is detected. this house,
At the electrode center position M1, for example, in the AA 'line of FIG. 3 which is located on the rod-shaped main body portion avoiding the electrode tip portion where the influence of the arc light 24 is large, the boundary positions P1 (X1, Y1) on both sides of the electrode image 1 ) And P2 (X2, Y2) are detected by image processing.

FIG. 4 shows the luminance of each pixel on the line AA 'in FIG. The brightness of the electrode image 1 portion in the range from Y1 to Y2 is high, and the background portion (Y <Y1, Y
2 <Y area) has low luminance.

FIG. 5 shows an example of data obtained by differentiating the luminance data on the line AA 'shown in FIG. The original image is a two-dimensional array of luminance, which is represented as f (Xi, Yi). f (Xi, Yi)
Represents the pixel (Xi, Yi) of the image f and represents the luminance at that point. The image after the differentiation processing is represented by g (Xi, Y
When expressed as i), the following equation is obtained.

G (Xi, Yi) = f (Xi, Yi-1)-
f (Xi, Yi) In the image after the differentiation processing, the boundary (Y1) on the left side of the electrode whose luminance changes from a low point to a high point has a minimum value, and the right side of the electrode whose luminance changes from a high point to a low point. Boundary part (Y
In 2), the maximum value is obtained. By detecting the minimum value and the maximum value, it is possible to find the left and right boundary portions of the electrode image 1.

The electrode center position M1 (Xm1, Ym1) is P
It is calculated from the following equation with the center of 1 and P2.

Xm1 = (X1 + X2) / 2 Ym1 = (Y1 + Y2) / 2 In the image during welding, the brightness of the obtained image may locally change due to the influence of arc light, electric noise, and the like. . In such a case, for example, the edge may be extracted by a method having both the smoothing process and the differential process shown in the following equation (hereinafter, this method is abbreviated as the smoothing differential process).

G (Xi, Yi) = f (Xi, Yi-1) + f
(Xi, Yi) -f (Xi, Yi + 1) -f (Xi, Yi +
2) The method of detecting the boundary position of the electrode 1 has been described above.
The same applies to the case of detecting the boundary position between the groove and the groove surface.

FIG. 6 shows an example of data obtained by differentiating an arbitrary horizontal line of the molten pool image. In the image after the differential processing, the boundary position (Y) between the left groove surface and the groove slope portion where the luminance changes from a low point to a high point.
5) and the minimum value at the left boundary position (Y3) of the molten pool, the boundary position (Y4) of the right molten pool where the luminance changes from a high point to a low point, and a boundary portion between the right groove slope portion and the groove surface. At the position (Y6), the maximum value is obtained (hereinafter, the boundary between the groove slope and the groove surface is referred to as a groove shoulder). This minimum,
By separately detecting the maximum values, it becomes possible to find the boundary position of the molten pool and the positions on both sides of the groove shoulder.

As a method for detecting a boundary portion, a method using differential processing and smoothing differential processing has been described. In addition, an electrode image and a background image by a binarization threshold processing, or a molten pool and a background image are used. A method of obtaining a boundary by separating or a method of obtaining a boundary by a second derivative process may be used.

FIG. 7 shows a specific embodiment of the present invention for detecting the positional deviation information shown in FIG. In FIG. 7, the detection of the groove wall boundary is omitted. In FIG. 7, W1 is a detection area (hereinafter, referred to as a window) for obtaining the electrode center position. The left and right boundary positions are detected on a plurality of horizontal lines in the electrode window W1 by the method described above. For the obtained left and right boundary position detection groups, for example, the average value of the Y-axis direction data of each of the left and right boundary position detection groups is obtained. The center point of the electrode center position M1 (Xm1, Ym1) may be obtained by calculation from the average value of the left and right boundaries thus obtained. Here, the position of the electrode center in the X direction is a detection value that is not particularly important because it is not used as electrode scanning information. W
Reference numerals 2 and W3 denote windows for detecting a left boundary and a right boundary in a direction orthogonal to the welding line of the molten pool 23 as described above. The molten pool windows W2 and W3 may be determined in advance as fixed regions on the screen, or may be set by freely changing based on the electrode center position detection result as described later. Also in this case, the molten window W2,
Alternatively, the left and right molten pool boundary positions are detected on a plurality of horizontal lines in W3. As described above, in the case of the electrode boundary detection, the left and right boundaries are determined from the average value of the boundary detection group in a plurality of lines. On the other hand, in the case of the molten pool, the boundary detection points located at the outermost side in the horizontal direction of the screen are detected as the respective boundary positions from a plurality of boundary position detection groups in the fusion window W2 or W3. The middle point of the molten pool center position M2 (Xm2, Ym2) may be obtained by calculation from the thus determined final values of the left and right boundaries. Each line for detecting a boundary is placed every other line in the vertical direction of the screen, every two lines, or the like.
It is not always necessary to set for each adjacent line.

Further, the displacement ΔY of the welding electrode is (Y
m2−Ym1). In the case of a narrow groove, the molten pool center position M2 (Xm2, Ym2)
From the experimental results, since the center of the groove bottom is almost indicated, the positional deviation ΔY of the welding electrode indicates the deviation of the electrode from the center of the groove.

FIG. 8 shows a flow chart of the present invention for detecting a displacement of the electrode with respect to the center of the molten pool from the image shown in FIG. Hereinafter, FIG.
The outline of the detection method will be described with reference to the flowchart of FIG.

After inputting the molten pool image in step S1, first, in step S2, a smoothing differentiation process is performed on a plurality of horizontal lines in a window W1.

In step S3, a plurality of minimum points at the left boundary of the electrode and a plurality of maximum points at the right boundary of the electrode are detected from the smoothed differential processing data, and these are stored as candidate points for the left and right boundary points. .

In step S4, the average value of the minimum point side candidate points and the average value of the maximum point side candidate points are obtained by using the left and right boundary point candidate points, and these points are set as the left and right boundary points of the electrode 1.

In step S5, the center position of the left and right boundary points of the electrode 1 obtained in step S4 is calculated, and this value is stored as the center position of the electrode 1.

Next, in step S6, windows W2 and W3 are set based on the result of detecting the electrode center position.

In step S7, a smoothing differentiation process is performed on a plurality of horizontal lines in the window W2.

In step S8, a plurality of minimum points at the left boundary of the molten pool are detected from the smoothed differential processing data in step S7, and these are stored as candidate points of the left boundary.

In step S9, the outermost (leftmost on the screen in FIG. 7) minimum point is determined using the candidate points for the left boundary point, and this point is set as the left boundary point of the molten pool 23.

In step S10, a smoothing differentiation process is performed on a plurality of horizontal lines in window W3.

In step S11, a plurality of local maximum points at the right boundary of the molten pool are detected from the smoothed differential processing data in step S10, and these are stored as candidate points for the right boundary point.

In step S12, the outermost (the rightmost point on the screen in FIG. 7) local maximum point is determined using the candidate point of the right boundary point, and this point is set as the right boundary point of the molten pool 23.

In step S13, the center position between the left boundary point of the molten pool 23 determined in step S9 and the right boundary point of the molten pool 23 determined in step S12 is detected, and this point is set as the central position of the molten pool.

In step S14, the difference between the center position of the molten pool 23 obtained in step S13 and the center position of the electrode 1 obtained in step S5 is calculated, and this is regarded as an electrode position shift. The electrode position shift determined so far is a detection result on the two-dimensional light receiving means, that is, the camera screen. It is necessary to convert the positional deviation obtained on this screen from various constants such as the imaging magnification of the camera into an actual positional deviation amount. In processing step S14, this conversion is performed.

The method of obtaining the center position of the electrode 1 in the present invention by calculation using the data on the detection of both-side boundary positions in the electrode width direction has been described. When the size of the width of the electrode 1 is known in advance, the size of the electrode 1 captured on the screen can be known in advance. In this case, the boundary position on one side of the electrode 1 may be detected, and the information may be used to calculate the electrode center position.

In FIGS. 7 and 8, the method of detecting the electrode center position deviation from the molten pool boundary center position and the method of electrode scanning have been described. In addition, the detection of the electrode center position deviation from the center of the groove wall boundary and the electrode copying may be performed.

FIG. 9 is a block diagram showing an embodiment of a method of controlling the movement of a Y traveling vehicle for the purpose of controlling the scanning in the direction orthogonal to the welding line of the welding electrode (Y direction) according to the present invention. In the operation according to this block diagram, an actual electrode displacement amount is detected with respect to a predetermined carriage movement command value, and the Y traveling carriage scanning control is performed based on the carriage movement command value and the actual electrode displacement amount. do.

In FIG. 9, reference numeral 25 denotes a movement command value of the Y traveling trolley 19 in each welding pass for performing, for example, multi-layer welding. The movement command value 19 is a target position of the electrode 1 determined by the input operation of the operator 26 before the start of welding or for each welding pass. Reference numeral 27 denotes a comparator, and reference numeral 10 denotes an image processing device for detecting the above-described electrode position shift. As shown, the movement command value 25 is input to the comparator 27. On the other hand, the electrode position deviation detection value ΔY detected by the image processing device 10 is input to the comparator 27. The comparator 27 calculates a difference (movement difference) between the movement command value 25 and the detected electrode position deviation detection value ΔY, and outputs the result to the movement control unit 28 of the Y traveling vehicle 19. The movement control unit 28 of the Y traveling vehicle 19 corrects the movement of the Y traveling vehicle 19 by an amount corresponding to the movement difference. Here, the movement control unit 28 of the Y traveling vehicle 19 may perform the movement control with a fixed movement amount sufficiently smaller than the movement difference. This fixed movement amount can be freely changed from outside. According to the above method, the carriage is not rapidly moved and changed, so that stable welding control can be performed. In addition, since the target position and the amount of movement of the electrode can be freely set from the outside, fine setting and control of welding conditions can be performed.

Next, a welding position automatic scanning control method to which the present invention is applied will be described.

In FIG. 1, B1 to B4 are already welded beads. B4 is the immediately preceding weld bead.
FIG. 1 shows an example in which a bead is overlapped on a bead B4 and welded. In the welding apparatus for performing the automatic copying, the two-dimensional light receiving means 6 is disposed in front of the electrode 1 in the traveling direction, and detects the displacement of the electrode 1. Then, based on the detected information, the scanning welding control of the electrode position is performed. Do.

FIG. 10 shows a flowchart of the electrode scanning control operation according to the present invention. In this operation, the overall control device 12 becomes a master station for managing the entire operation, and the welding power source 14, the electrode position control device 13, and the image processing device 10 are in a slave station relationship. That is, the slave power supply 14, the electrode position control device 13, and the image processing device 10
Performs a predetermined operation according to a command from the overall control device 12 which is the master station.

After the start of the operation, in step F1, the general control device inquires the current position of the electrode to the electrode position control device, and receives a report of the position information (step F19).

In step F2, the general control device issues a movement command for raising the electrode to the electrode position control device, and raises the electrode (step F20).

In step F3, the general control device issues a movement command to the reference position at which welding is started to the electrode position control device, and moves the electrode to the reference position (step F21).

In step F4, the general control device issues a command to the electrode position control device to move the electrode position to a predetermined height at which the arc can be started, and lowers the electrode to the predetermined position (step F22).

In step F5, the general control device issues an arc start (ON) command to the welding power source, and turns on the arc.
Is started (step F26).

In step F6, the general control device issues a command to start traveling in the X direction to the electrode position control device, and starts traveling in the X direction (step F23).
The X-direction traveling operation is continued until an X-axis traveling stop command described later is issued.

In step F7, the general control device issues a detection command to the image processing device, and the image processing device detects the electrode position deviation in the above-described procedure (step F7).
28).

In step F8, the general control device inquires the current position of the electrode position to the electrode position control device,
The location information report (step F24) is received.

In step F9, the general control device issues a command to report the result of detecting the electrode position deviation to the image processing device, and the image processing device reports the result (step F29).
Receive.

In step F10, the electrode current position information in step F8 and the electrode position deviation detection result information in step F9 are stored internally.

In step F11, the electrode tip following position is calculated based on the electrode position deviation detection information.

In step F12, the information calculated in step F11 is transferred to the electrode position control device to perform the correction control of the Y traveling bogie position (step F25).

In step F13, it is determined whether or not the welding operation is at the end position based on the current electrode position information, and the electrode position is not yet at the end position (it is determined and stored in advance in the overall control device). In some cases, the process returns to the processing step F7 to repeat the above operation. On the other hand, when it is determined that the electrode position has exceeded the end position, the process proceeds to processing step F14.

In step F14, the general control device issues an arc end (OFF) command to the welding power source and turns on the arc.
Is stopped (step F27).

In step F15, the overall control device issues a command to stop traveling in the X direction to the electrode position control device, and stops traveling in the X direction.

In step F16, it is determined whether or not the welding of all the welding passes planned in advance has been completed. If it has been completed, a series of operations is completed, but if not, the process proceeds to step F2.

Although the welding end position in step F16 is determined and stored in advance in the overall control device, it may be determined by detecting the position with a limit switch or the like.

In the present invention, although not shown in FIG. 10, when the next welding pass is welded, the welding is performed using the welding conditions in the immediately preceding or previous welding pass, that is, the above-described electrode scanning correction control data. A method is also acceptable. Whether the welding of each welding pass is performed using the previous welding condition control data or the content of each processing step described above is to be incorporated in advance as a database in the overall control device.

As shown in FIG. 6, according to the present invention, it is possible to find not only the positions on both sides of the molten pool and the center thereof, but also the positions of the shoulders on both sides of the groove and the center thereof. Therefore, the electrode center position shift with respect to the center position of the shoulders on both sides of the groove may be detected, and the position scanning control of the electrode may be performed based on this position shift information. Further, in the above-described step F11, the detected center detection position of the molten pool is compared with the detection positions of the center of both sides of the groove, and when the difference is within a predetermined value, the copying data may be adopted.

Note that the electrode position control mechanism 15 of the present invention
A Z traveling shaft 20 integrally arranged on an X traveling vehicle 17, a Z traveling vehicle 21 traveling on the Z traveling shaft, and a Z traveling vehicle 2
1 is composed of a Y traveling shaft 18 and a Y traveling vehicle 19 traveling on the Y traveling axis.
A configuration in which the mounting structure of the shaft is reversed may be adopted.

The electrode position control mechanism 15 of the present invention
For example, the present invention can be applied to a self-propelled welding robot, an articulated welding robot that has no traveling axis in the welding line direction (X) and travels independently on a plane, or a robot that travels on a traveling axis provided on the outer periphery of a pipe. It is not particularly limited.

[0072]

According to the welding position automatic profiling control device and the groove welding method for the member to be welded according to the present invention, at least one side boundary of a portion which does not overlap with the welding pool image of the welding electrode image picked up by the two-dimensional light receiving means. Since the misalignment control device is configured to calculate the misalignment by detecting the part, the position of the welding electrode can be detected with high accuracy without being affected by the welding pool image and the arc image, and the welding can be easily performed by the welding arc light. Even in the case of an electrode image, the position of the welding electrode can be detected with high reliability. In addition, since the misalignment control device is configured to calculate the misalignment by detecting at least one boundary portion of the welding pool image captured by the two-dimensional light receiving means, an assembling error of the groove portion of the member to be welded and a welding arc are formed. The position of the welding target portion can be detected with high accuracy in a state where the influence of the change in the position of the welding target portion caused by thermal deformation of the member to be welded due to heat is small. Furthermore, since the misalignment control device is configured to calculate the misalignment by detecting at least a plurality of locations on at least one boundary portion of the welding electrode image or the welding pool image captured by the two-dimensional light receiving means, the welding arc light that is easily fluctuated. , The position of the welding electrode or the welding pool can be detected with high accuracy. This makes it possible to obtain a high-quality weld bead because the displacement of the electrode is copied with high accuracy by a simple detection and calculation method using the two-dimensional light receiving means having a simple and small configuration.

[Brief description of the drawings]

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

FIG. 2 is a schematic view of a molten pool and an electrode image taken by a two-dimensional light receiving unit of the present invention.

FIG. 3 is a basic schematic diagram of misregistration detection information for performing automatic welding copying according to the present invention.

FIG. 4 is a diagram showing a luminance distribution of an electrode image according to the present invention.

FIG. 5 is a diagram showing data obtained by differentiating an electrode image according to the present invention.

FIG. 6 is a diagram showing data obtained by differentiating a molten pool image according to the present invention.

FIG. 7 is a specific schematic diagram of electrode displacement detection information of the present invention.

FIG. 8 is a view showing a flowchart for detecting an electrode position shift from a captured image according to the present invention.

FIG. 9 is a block diagram showing one embodiment of a traveling bogie movement control method according to the present invention.

FIG. 10 is a diagram showing a flowchart of an electrode position automatic scanning control operation of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electrode, 2, 3 ... Member to be welded, 4 ... Groove, 5 ... Arc generating part, 6 ... Light receiving means, 7 ... Interference filter, 8 ... Two-dimensional light receiving means, 9 ... Light receiving means control circuit, 10 ... Image Processing device, 11 TV monitor, 12 Overall control device, 13
Electrode position control device, 14: welding power supply, 15: welding position control mechanism, 16: X traveling axis, 17: X traveling carriage, 18: Y
Travel axis, 19 ... Y travel carriage, 20 ... Z travel axis, 21 ... Z
Traveling trolley, 25 ... Y traveling trolley movement command value, 27 ... Comparator, 28 ... Y traveling trolley movement control command value.

Claims (7)

[Claims] A non-consumable welding electrode having a front end portion movably disposed facing a groove of a member to be welded, an electrode position control mechanism for driving the welding electrode, and the welding by the electrode position control device. An electrode position control device for controlling the movement of the electrode,
It is arranged movably forward in the welding line direction of the welding electrode,
And two-dimensional light receiving means for imaging the vicinity of an arc generating portion generated between the welding electrode and the member to be welded, and calculating the position shift of the welding electrode from the image captured by the two-dimensional light receiving means, the electrode In a welding position automatic copying control device including a position shift control device that controls a position control device, the position shift control device does not overlap with a welding pool image and an arc image of a welding electrode image captured by the two-dimensional light receiving unit. A welding position automatic profiling control device for detecting a position shift by detecting at least one boundary portion of a portion. 2. A non-consumable welding electrode having a tip end movably disposed facing a groove of a member to be welded, an electrode position control mechanism for driving the welding electrode, and the welding by the electrode position control device. An electrode position control device for controlling the movement of the electrode,
It is arranged movably forward in the welding line direction of the welding electrode,
And two-dimensional light receiving means for imaging the vicinity of an arc generating portion generated between the welding electrode and the member to be welded, and calculating the position shift of the welding electrode from the image captured by the two-dimensional light receiving means, the electrode In a welding position automatic tracing control device having a position control device for controlling a position control device, the position control device detects a position of at least one side boundary of a weld pool image captured by the two-dimensional light receiving unit. An automatic welding position copying control device, which calculates a deviation. 3. A non-consumable welding electrode having a tip end movably disposed facing a groove of a member to be welded, an electrode position control mechanism for driving the welding electrode, and the welding by the electrode position control device. An electrode position control device for controlling the movement of the electrode,
It is arranged movably forward in the welding line direction of the welding electrode,
And two-dimensional light receiving means for imaging the vicinity of an arc generating portion generated between the welding electrode and the member to be welded, and calculating the position shift of the welding electrode from the image captured by the two-dimensional light receiving means, the electrode In a welding position automatic scanning control device including a position shift control device that controls a position control device, the position shift control device includes a welding electrode image or a welding pool image captured by the two-dimensional light receiving unit at least on one side boundary portion. An automatic welding position profiling control device characterized by detecting a plurality of positions and calculating a position shift. 4. A non-consumable welding electrode having a tip end movably disposed facing a groove of a member to be welded, an electrode position control mechanism for driving the welding electrode, and the welding by the electrode position control device. An electrode position control device for controlling the movement of the electrode,
It is arranged movably forward in the welding line direction of the welding electrode,
And two-dimensional light receiving means for imaging the vicinity of an arc generating portion generated between the welding electrode and the member to be welded, and calculating the position shift of the welding electrode from the image captured by the two-dimensional light receiving means, the electrode In a welding position automatic copying control device including a position shift control device that controls a position control device, the position shift control device does not overlap with a welding pool image and an arc image of a welding electrode image captured by the two-dimensional light receiving unit. A welding position automatic profiling control device, wherein at least one side boundary portion of a portion is detected, and at least one side boundary portion of a welding pool image captured by the two-dimensional light receiving means is detected to calculate a position shift. 5. A non-consumable welding electrode having a tip end movably disposed facing a groove of a member to be welded, an electrode position control mechanism for driving said welding electrode, and said welding by said electrode position control device. An electrode position control device for controlling the movement of the electrode,
It is arranged movably forward in the welding line direction of the welding electrode,
And two-dimensional light receiving means for imaging the vicinity of an arc generating portion generated between the welding electrode and the member to be welded, and calculating the position shift of the welding electrode from the image captured by the two-dimensional light receiving means, the electrode In a welding position automatic copying control device including a position shift control device that controls a position control device, the position shift control device does not overlap with a welding pool image and an arc image of a welding electrode image captured by the two-dimensional light receiving unit. Detecting a plurality of locations on at least one side boundary portion of the portion, and detecting a plurality of locations on at least one side boundary portion of the weld pool image picked up by the two-dimensional light receiving means and calculating a positional shift. Copying control device. 6. A non-consumable welding electrode in the form of a rod having a pointed tip, which is movably arranged with the tip facing a groove of the member to be welded, and an X-carriage, a Y-carriage, and a Z-carriage. An electrode position control mechanism that can drive the welding electrode in the X-axis, Y-axis, and Z-axis directions; an electrode position control device that controls driving of the welding electrode by the electrode position control device; an interference filter; A two-dimensional light receiving means having a television, arranged movably forward in the welding line direction of the welding electrode, and imaging an area near an arc generating portion generated between the welding electrode and the member to be welded; A differential or smoothing differential processing unit that extracts a maximum point or a minimum point at an edge portion that changes from a dark portion to a bright portion or an edge portion that changes from a bright portion to a dark portion in an image captured by the three-dimensional light receiving means. Of the welding electrode An image processing apparatus for calculating a location shift,
A welding position automatic tracing control device comprising: an overall control device that controls the electrode position control device so as to correct the displacement of the welding electrode based on the displacement information calculated by the image processing device. The apparatus detects, by a differential or smoothing differential processing unit, a plurality of portions of at least one side boundary portion or both side boundary portions of the rod-shaped main body portion that does not overlap with the welding pool image and the arc image in the welding electrode image captured by the two-dimensional light receiving unit. And extracting a local maximum point or a local minimum point, and differentiating or smoothing a plurality of portions of at least one side boundary part of the welding pool image and at least one side boundary part of the groove shoulder image captured by the two-dimensional light receiving means. And detecting a local maximum point or a local minimum point to calculate a positional deviation between the two points. 7. A tip of a non-consumable welding electrode is arranged opposite to a groove of a member to be welded, and an arc is generated between the welding electrode and a groove of the member to be welded to form a welding pool. While being generated, it is driven in the direction of the welding line, and the vicinity of the arc generating portion generated between the welding electrode and the member to be welded is imaged by the two-dimensional light receiving means from the front in the welding line direction of the welding electrode. In the groove welding method for a member to be welded, the position of the welding electrode is calculated from the image captured by the light receiving unit and controlled to correct the position deviation of the welding electrode, and welding is performed. A position shift is calculated by detecting at least one boundary portion of a portion of the picked-up weld electrode image that does not overlap with the weld pool image and the arc image, and correcting the position shift of the welding electrode based on the calculated position shift. Welding parts Groove part welding method.