JP2008221281A - Position detection system for automatic welding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a position detection system for an automatic welding machine, which, when applying a different image-processing parameter, enables confirmation of the result of image processing, which is displayed on a teach pendant, based on the measured distance data obtained by a search operation without performing another search operation thereafter. <P>SOLUTION: When receiving a command from a keyboard 41 of a teach pendant TP to conduct an image re-analysis, a robot controller RC conducts an image analysis of a weld joint according to the image processing parameter inputted by adjustment-input executed based on the measured distance data that are stored in the first storage area in a storage part set in the robot controller RC. The robot controller RC obtains, based on the image analysis, groove information including characteristic points relating to the groove shape of the weld joint, and a display 42 displays the image analysis data obtained according to the image processing parameter inputted by adjustment-input. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a position detection system for an automatic welder.

  In the position detection system of an automatic welder, the position displacement of the workpiece is detected by operating the manipulator while irradiating the workpiece with the laser from the laser displacement sensor attached to the welding torch of the manipulator (robot). This is reflected in the welding program.

  The system has a one-way search function for detecting the displacement. In this one-way search function, the detection point P1 is detected by operating the laser displacement sensor LS in any one direction (search direction) as shown in FIG. 15, and the deviation (deviation amount) between the reference point P0 and the detection point P1 is detected. This is a function of calculating and saving the deviation amount in one direction of the workpiece W in the deviation amount correction file F. The reference point P0 is a point detected by the laser displacement sensor LS when the workpiece W is located at the original position. Then, the actual workpiece can be welded by reflecting the calculated deviation amount in the welding program. In FIG. 15, an approach point AP indicates a point at which the laser beam from the laser displacement sensor LS starts to be projected.

The one-way search operation is performed according to the following procedure.
As shown in FIG. 16 (a), in the robot controller RC, when the point just before the one-way search command is reached by the reproduction operation by the program that is already taught teaching data, the laser irradiation command is sent to the laser displacement sensor controller LU. Is output, and then a one-way search command is output. In response to this laser irradiation command, the laser displacement sensor control device LU turns on the laser displacement sensor LS, and the laser displacement sensor LS starts distance measurement upon execution of the one-way search command. At the same time, under the control of the robot controller RC, the laser displacement sensor LS starts operation toward the search target point together with the welding torch of the manipulator. The laser displacement sensor LS outputs distance measurement data obtained by projecting the laser beam to the laser displacement sensor control device LU. The laser displacement sensor control device LU detects the height based on the distance measurement data, and continues the measurement until the height reaches the determined reference height.

  As shown in FIG. 16B, when the laser displacement sensor LS detects the workpiece W, that is, when the height detection result is the reference height, the laser displacement sensor control device LU turns off the laser of the laser displacement sensor LS. To turn on the touch detection input of the robot controller. When the robot control device RC receives the touch detection input, the robot control device RC stops the manipulator, calculates the amount of deviation between the previously taught reference point and the point stopped during the search, and stores it in the deviation amount correction file. As described above, the position displacement of the workpiece can be detected by simply inputting the touch detection input to the object to the robot control device using the laser displacement sensor.

  The distance measurement data obtained by the laser displacement sensor is stored in the memory of the laser displacement sensor controller LU. Then, the laser displacement sensor control device LU performs image processing on the distance measurement data based on image processing parameters set and input in advance to obtain image data, and obtains feature points and necessary physical quantities for the image data. I am doing so. The result of the image processing is displayed on a teach pendant (not shown) display.

In Patent Document 1, welding is performed by automatically selecting the target position and welding conditions of the welding torch according to the shape of the welded joint obtained by detecting the groove cross-section of the laser welded joint, and detection based on the groove information. A means for determining whether or not is OK is disclosed. Patent Document 2 discloses a robot device with a visual sensor that displays image data or image analysis results measured by a scanner type laser sensor on a teach pendant. Patent Document 3 discloses an image processing apparatus in which an image display monitor for displaying an image captured by a visual sensor camera or an image stored in a memory is attached to a teach pendant. Patent Document 4 discloses a system using a visual sensor camera, in which an image processing apparatus teaching operation panel provided in place of a teach pendant has a monitor display and a robot teaching operation function. Is disclosed.
JP 2001-334366 A Japanese Patent Laid-Open No. 09-183087 Japanese Patent Laid-Open No. 5-66825 JP 2001-135589 A

  As described above, the distance measurement data obtained by the laser displacement sensor is subjected to image processing based on image processing parameters, and the result of the image processing is displayed on the display of a teach pendant (not shown). Yes. However, appropriate image processing parameters vary depending on the groove shape, gloss, and processing accuracy of the workpiece.

  For this reason, at the beginning of the system introduction or when a new teaching is performed on a workpiece with a different groove or surface condition, a search operation is performed after appropriately changing the image processing parameters, and image analysis is performed on the teach pendant display. There is often an operation of searching for an optimum image processing parameter by repeating the operation of confirming the result. In this search operation, it is necessary to operate the robot at the search start position every time and repeat the search operation. For this reason, during this search work, in addition to the time for operating the robot, when there are a plurality of workers, there is a problem that other people cannot work around the workpiece. As a result, there is a problem that the time required for system introduction and new teaching increases. In addition, readjustment is performed when the feature points for the image data cannot be correctly recognized. In this case also, it is necessary to search the robot for adjustment.

  Note that Patent Documents 1 to 4 do not describe how to check image processing parameters or perform setting of image processing parameters from a teach pendant.

  An object of the present invention is an automatic welding machine that can confirm on a teach pendant image analysis results when different image processing parameters are applied without performing a search operation on the basis of distance measurement data obtained by a search operation. It is to provide a position detection system.

  In order to solve the above problems, the invention according to claim 1 is directed to a laser displacement sensor that projects laser light onto a welded joint to acquire distance measurement data, and the laser displacement sensor is welded together with a welding torch. A manipulator that performs a search operation in a direction that crosses the distance, first storage means that stores the distance measurement data, and image analysis of the weld joint according to image processing parameters based on the distance measurement data, and the welding based on the image analysis In a position detection system of an automatic welding machine provided with groove information acquisition means for acquiring groove information including a feature point related to a groove shape of a joint, the groove information and processed distance measurement data after image analysis ( Hereinafter, second storage means for storing groove information and processed distance measurement data after image analysis is referred to as image analysis data), and display for displaying the image analysis data A portable operation means including a parameter input unit for adjusting and inputting the image processing parameter, and a re-image analysis instruction input unit for inputting an instruction for performing re-image analysis in accordance with the adjusted and input image processing parameter. When there is an instruction to perform re-image analysis from the image analysis instruction input unit, the groove information acquisition unit performs image analysis of the weld joint according to the image processing parameter that has been adjusted and input based on the distance measurement data of the first storage unit. The gist of the position detection system of the automatic welding machine is to create new image analysis data, and the display unit displays the new image analysis data.

  According to a second aspect of the present invention, in the first aspect, the portable operation unit includes a third storage unit that stores the image processing parameter adjusted and input by the parameter input unit.

  The invention of claim 3 is the storage area for storing image analysis data before input of image processing parameter adjustment (hereinafter referred to as before image processing parameter adjustment). A storage area for storing image analysis data after image processing parameter adjustment input (hereinafter referred to as image processing parameter adjustment) is provided.

  According to a fourth aspect of the present invention, in the first or second aspect, the second storage unit stores the image analysis data before and after adjustment of the image processing parameters as files.

  A fifth aspect of the present invention provides the method according to the fourth aspect, wherein the second storage unit identifies the file name of the created file differently each time the image analysis data obtained by performing image analysis with different image processing parameters is filed. It is characterized by giving a code.

  According to a sixth aspect of the present invention, in the fourth aspect, the portable operation means includes distance measurement data stored in the first storage means, image analysis data before image processing parameter adjustment stored in the second storage means, or an image Display switching means is provided for selecting any one of the image analysis data after adjusting the processing parameters and switching and displaying the selected data on the display unit.

  According to a seventh aspect of the present invention, the display unit according to the fourth aspect of the present invention includes the distance measurement data stored in the first storage unit, the image analysis data before image processing parameter adjustment stored in the second storage unit, and the image processing parameter adjustment. Of the subsequent image analysis data, there is a display mode for displaying one data and a display mode for simultaneously displaying at least two data. The portable operation means has a display mode selection input for selecting the display mode. Means is provided, and the display unit executes one of the display modes in response to a display mode selection input by the display mode selection input means.

  As described above in detail, according to the first aspect of the present invention, based on the distance measurement data obtained by the search operation, the image analysis results when different image processing parameters are applied without performing the search operation thereafter. An automatic welding machine position detection system that can be confirmed on a teach pendant can be provided. As a result, there is an effect that the adjustment time of image processing in system introduction or new teaching can be shortened.

  According to the invention of claim 2, by providing the third storage means, it is possible to store the image processing parameter adjusted and input by the parameter input unit, and to re-acquire groove information by the stored image processing parameter. It can be carried out.

  According to the third aspect of the present invention, the image processing apparatus has storage areas for storing image analysis data before adjustment of image processing parameters and image analysis data after adjustment. As a result, the image analysis data obtained according to each image processing parameter can be displayed on the display unit.

  According to the fourth aspect of the present invention, the image analysis data obtained according to the respective image processing parameters before and after the image processing parameter adjustment can be displayed on the display unit.

  According to the invention of claim 5, when there are a plurality of search operations in the teaching data which is one program, the reproduction operation is performed, and the distance measurement data is stored in the first storage means and the image processing is performed. Image analysis data image-analyzed according to the parameters is stored in the second storage means. At this time, because the groove shape is different, each time the image analysis data obtained by image analysis with different image processing parameters is filed, the file names to which different identification codes are assigned to each file Created.

  Thereafter, when the image processing parameters are adjusted and input to the image analysis data obtained according to the different image processing parameters in the re-image analysis instruction input unit of the portable operation means, Image analysis of the welded joint can be performed according to the processing parameters.

  According to the invention of claim 6, by the display switching means, the distance measurement data stored in the first storage means, the image analysis data before image processing parameter adjustment stored in the second storage means, or the image after image processing parameter adjustment Any one of the analysis data can be selected and displayed on the display unit. As a result, the presence or absence of image processing parameters or the effect of changing the adjustment can be confirmed.

  According to the invention of claim 7, by having a display mode for displaying one data among the distance measurement data and the image analysis data before and after the image processing parameter adjustment, and a display mode for simultaneously displaying at least two data, The presence / absence of image processing parameters and the effect of presence / absence of adjustment can be confirmed.

Hereinafter, an embodiment in which a position detection system for an automatic welding machine according to the present invention is applied to a control device 10 for a welding robot will be described with reference to FIGS.
FIG. 1 is a block diagram illustrating a configuration of a control apparatus 10 for a welding robot. The control device 10 of the welding robot controls the workpiece (work object) W so as to automatically perform arc welding. The welding robot control device 10 includes a manipulator M that performs a welding operation, a robot control device RC that controls the manipulator M, and a laser displacement sensor LS as a sensor that detects the shape of the workpiece W.

  In addition, a teach pendant TP as a portable operation unit is connected to the robot controller RC. The teach pendant TP is provided with a keyboard 41 including a numeric keypad and various keys, and a display 42 including a liquid crystal display device. Various teaching data are input to the robot controller RC by the keyboard 41. The teach pendant TP of this embodiment corresponds to a portable operation means. The keyboard 41 of this embodiment corresponds to a parameter input unit, a re-image analysis instruction input unit, and a display switching unit. The display 42 corresponds to a display unit.

  The manipulator M includes a base member 12 fixed to a floor or the like, and a plurality of arms 13 connected via a plurality of shafts. A welding torch 14 as a work tool is provided at the distal end portion of the arm 13 located on the most distal side. The welding torch 14 includes a wire 15 as a filler material, generates an arc between the tip of the wire 15 fed by a feeding device (not shown) and the workpiece W, and welds the wire 15 with the heat. To weld the workpiece W. A plurality of motors (not shown) are disposed between the arms 13, and the welding torch 14 can be freely moved back and forth and left and right by driving the motors. Note that front and rear refers to the direction in which the welding torch 14 travels along the weld line as the front, and the opposite direction 180 degrees as the rear. Left and right are referred to as left and right with reference to the direction in which the person travels.

  The robot controller RC is composed of a computer as shown in FIG. That is, the robot controller RC is a rewritable EEPROM 21 that stores a CPU (Central Processing Unit) 20, various programs for controlling the manipulator M, and a plurality of image analysis programs prepared according to various groove shapes. And a RAM 22 serving as a working memory, and a storage unit 23 including a rewritable nonvolatile memory for storing various data. In the present embodiment, the CPU 20 corresponds to an image analysis unit and a groove information acquisition unit.

The storage unit 23 includes a first storage area 23a, a second storage area 23b, a third storage area 23c, and a fourth storage area 23d.
The first storage area 23a is an area for storing distance measurement data obtained by measurement with the laser displacement sensor LS, and corresponds to the first storage means of the present invention.

  The second storage area 23b stores groove information before adjustment of image processing parameters (to be described later) and processed distance data after image analysis (hereinafter referred to as groove information and processed distance data after image analysis). Area Pa for storing image analysis data) and area Pb for storing image analysis data after image processing parameter adjustment. The second storage area 23b corresponds to second storage means.

  The third storage area 23c has an area Qa for storing image processing parameters input before adjustment with the keyboard 41 and an area Qb for storing image processing parameters input with the keyboard 41. The third storage area 23c corresponds to third storage means.

  The fourth storage area 23d is an area for storing image analysis data for obtaining feature points and the like of a groove shape in a one-way search performed after a one-way search for acquiring a reference point is performed. It is.

The storage unit 23 also includes a teaching data storage area that stores teaching data input from the keyboard 41, although not shown.
The robot controller RC controls the motor to drive the welding torch 14 along the main track of preset teaching data. Further, the robot controller RC outputs welding conditions such as a welding current and a welding voltage to the welding power source WPS, and causes the welding operation to be performed by electric power supplied from the welding power source WPS through the power cable PK.

  The laser displacement sensor LS is a scanning type laser displacement sensor that measures the distance to the workpiece W by light emission and light reception of a laser, and is mounted on the welding torch 14. The laser displacement sensor LS includes a light emitting unit that emits light toward the workpiece W, a light receiving unit that receives the laser reflected by the workpiece W, and the like (both not shown). The laser emitted from the light emitting unit is irregularly reflected by the workpiece W and received by the light receiving unit. The light receiving unit is constituted by a CCD line sensor, for example, and measures the distance from the center of gravity of the received light amount distribution to the workpiece W.

The robot controller RC controls the laser displacement sensor LS and detects the groove shape of the workpiece W from the measured distance information.
Next, the one-way search procedure for the groove information acquisition function in the robot controller 10 will be described with reference to FIGS. 10, 11A, and 11B.

  In order to realize the above function, as a precondition, the sensor head LSa is attached so that the laser irradiation direction of the laser displacement sensor LS is parallel to any axis of the tool coordinate system, and FIG. 1 shows a welding torch 14 as a tool, and the tool coordinate system is represented as shown in FIG. In this embodiment, as shown in FIG. 2B, the sensor head LSa of the laser displacement sensor LS is attached to the welding torch 14 so that the laser irradiation direction is the Z-direction.

  In addition, before the welding operation is performed, teaching data indicating the operation of the manipulator M, welding conditions, and the like when welding is performed is input to the robot controller RC via the teach pendant TP, and the storage unit 23 is not illustrated. It is stored in the teaching data storage area.

  (1) First, the robot controller RC performs a reproduction operation of the manipulator M according to the teaching data, performs a search operation for the laser displacement sensor LS in one direction as shown in FIG. Then, it is filed and stored in the area Pa of the second storage area 23b of the storage unit 23. The method of acquiring this reference point will be described later for convenience of explanation.

  (2) Next, after returning the manipulator M, the robot controller RC performs a reproduction operation (that is, a search operation in one direction) according to the teaching data, and the laser displacement sensor LS is positioned immediately before the groove information acquisition command. When it reaches, a laser irradiation command is output to the laser displacement sensor LS as shown in FIG. At the same time, the robot controller RC takes into account the detection pattern number for the image analysis that has been input in advance by the teach pendant TP, the detection parameter corresponding to the detection pattern number and the data sampling cycle that has been input in advance by the teach pendant TP. Then, the image analysis program stored in the EEPROM 21 is executed.

  Here, the detection parameter is a set of numerical values used at the time of image analysis by the robot controller RC. There are a plurality of detection parameters corresponding to the detection pattern number, and the meaning of the detection parameter changes depending on the detection pattern number.

Examples of detection parameters will be described later.
Note that the robot controller RC uses the position of the manipulator M at the time when the laser irradiation command is output to the laser displacement sensor LS as the search start point coordinates (that is, distance measurement data) of the robot coordinate system in the first memory of the storage unit 23. Store in area 23a.

  (3) Thereafter, in response to the laser irradiation command, the laser displacement sensor LS starts distance measurement (that is, acquisition of distance measurement data), and at the same time, the welding torch 14 of the manipulator M starts operation toward the search end point. To do. Then, distance measurement data obtained by projecting the laser light is input from the laser displacement sensor LS to the robot controller RC.

  In the robot controller RC, during laser irradiation, distance measurement data (that is, distance data) received from the laser displacement sensor LS at a period determined by the data sampling period is stored in the first storage area 23a of the storage unit 23. (See FIG. 11 (a)).

  (4) When the manipulator M reaches the search end point, the robot controller RC transmits a laser extinguishing command to the laser displacement sensor LS (see FIG. 11B). In response to the command, the laser displacement sensor LS is turned off. At this time, the robot controller RC uses the position of the manipulator M at the time when a laser extinguishing command is output to the laser displacement sensor LS as the search end point of the robot coordinate system (that is, distance measurement data). Store in one storage area 23a.

  (5) After the search operation is completed, the robot controller RC performs image processing on the distance measurement data obtained in time series. The data on which this image processing is performed is hereinafter referred to as image data. Then, a feature point for the image data on the memory is obtained. Also, the robot controller RC obtains physical quantities such as a gap amount and a groove angle according to the groove. A detailed description of how to obtain the feature points and physical quantities will be described later with examples.

(Feature points and physical quantities)
Here, the feature points and physical quantities as groove information will be described by taking V-shaped joints, lap joints, and arc positions as weld joints as examples.

(V-shaped joint)
In the case of the V-shaped joint, as shown in FIG. 5, in the groove of the left and right welding base materials (work W), the middle point P of the groove located on the extended plane E on the upper surfaces of both welding members is a characteristic point. In the case of the V-shaped joint, the gap amount, groove depth, groove angle θ1, and groove angle θ2 are physical quantities. As shown in FIG. 5, the gap amount G is the distance between the edge portions of the left and right weld base materials of the groove that are spaced apart from each other (the distance between the open tips of the left and right weld base materials). The groove depth H is the depth of the groove. The groove angle θ1 is an angle on the groove side of one welding base material, and the groove angle θ2 is an angle on the groove side of the other welding base material.

(Lap joint)
In the case of the lap joint, as shown in FIG. 6, the end point of the upper plate U (referred to as the upper plate angle) is a feature point. In addition, the distance between the upper plate U and the lower plate S is a gap amount which is a physical quantity. Note that the gap amount of the lap joint is obtained by calculating the difference between the distance measurement data from the laser displacement sensor LS to the lower plate S and the distance measurement data from the upper plate U, and based on the difference, the preset upper plate U It can be obtained by subtracting the plate thickness.

(Calculation of feature points and physical quantities)
Here, calculation of feature points and physical quantities by image analysis performed by the robot controller RC will be described. This image analysis is executed in the following order (1) to (10) after an image analysis program corresponding to the detection pattern number shown in Table 1 is read by the CPU 20 of the robot controller RC. In the following description, detection parameters referred to when the CPU 20 executes are those described in detection parameters 1 to 9 shown in Table 1. These detection parameters are detection conditions for calculating feature points and physical quantities.

  Here, the detection pattern number, the data sampling period, and the detection parameters 1 to 9 described in Table 1 correspond to image processing parameters. This image processing parameter is input from the keyboard 41 of the teach pendant TP, and is stored in the area Qa for storing the image processing parameter before adjustment in the third storage area 23c of the storage unit 23.

  The detection parameter 1 and the detection parameter 2 respectively define an upper limit value and a lower limit value of data. The detection parameter 3 and the detection parameter 4 define an offset amount and a straight line length in the groove, respectively. The detection parameter 5 defines the target position to be a feature point. “0” is the deepest part of the groove, “1” is the upper left edge of the groove, and “2” is the groove. “3” designates the midpoint of the groove, and “4” designates the approximate straight line intersection. Which one is to be used as a feature point is set in the image analysis program when the operator inputs in advance from the teach pendant TP.

  The detection parameter 6 defines a threshold value for endpoint detection. The detection parameter 7 defines the offset amount outside the groove. The detection parameter 8 defines a filter mode for filtering the image data, “0” is no filter, “1” is moving average, “2” is median, “3” is both moving average and median processing. Means. Which filter processing is performed is set in the image analysis program in advance by the operator from the teach pendant TP. The detection parameter 9 defines the filter window width.

（１）まず、ロボット制御装置ＲＣは検出パラメータ８でフィルタモードを設定する。

(1) First, the robot controller RC sets the filter mode with the detection parameter 8.

(2) Next, the robot controller RC filters the image data according to the set filter mode with the filter window width specified by the detection parameter 9.
(3) Subsequently, the robot controller RC excludes data outside the range of the detection parameter 1 (data upper limit value) to the detection parameter 2 (data lower limit value) from the distance measurement distance, and searches for the data deepest portion in the data. (See FIG. 7). In FIG. 7, black dots indicate sampling points at the time of distance measurement data acquisition.

  (4) Next, the robot controller RC draws approximate straight lines each having a straight line length designated by the detection parameter 4 at both ends of the groove centering on the position separated from the deepest portion by the offset amount designated by the detection parameter 3 (see FIG. 7).

  (5) Subsequently, the robot control device RC sets the points at which the distance specified by the detection parameter 6 (that is, the threshold value for detecting the end point) starts to be separated from each straight line among the measured sampling points (see FIG. 7).

  (6) Next, the robot controller RC designates a feature point with the detection parameter 5 (see FIG. 7). In this embodiment, it is assumed that “3” is selected in advance as an image analysis program by an operator input. Note that an acute angle is selected as each crossing angle.

(7) Subsequently, the robot controller RC sets the distance G between the open ends of the left and right welding base materials as the gap amount G (see FIG. 7).
(8) Next, the robot controller RC draws an approximate straight line outside the left groove centering on the position moved to the left by the offset amount specified by the detection parameter 7 from the left end of the groove. Similarly, a straight line outside the right groove is drawn (see FIG. 7).

(9) Next, the robot controller RC sets the distance between the approximate straight line outside the left groove and the deepest part as the groove depth (see FIG. 7).
(10) Then, the robot controller RC opens the intersection angle between the left groove portion approximate line and the left groove outside approximate line as the groove angle θ1, and the right groove portion approximate line and the right groove outside approximate line as the intersection angle θ1. The tip angle θ2 is set (see FIG. 7).

  In addition, although there exists a place where the inclination changes steeply in the lap joint or the V-shaped joint, the groove information acquisition function can be applied even when this is not the case. For example, the arc position can be searched. The image analysis procedure at the arc position is as follows (1) to (7).

  This image analysis is executed by reading an image analysis program corresponding to the detection pattern number shown in Table 2 by the CPU 20 of the robot controller RC. The selection of the image analysis program is determined in advance by operator input. The detection parameters referred to when the CPU 20 executes are those described in the detection parameters 1 to 6 shown in Table 2. In this case, these detection parameters are detection conditions for calculating feature points.

  The detection parameter 1 here defines the section length at the time of vertex search. The detection parameter 2 defines the amount of decrease from the apex. The detection parameter 3 is a height difference threshold value when searching for points A and B. The detection parameter 4 defines the radius of the arc to be searched. The detection parameter 5 defines a filter mode for filtering the image data. “0” indicates no filter, “1” indicates moving average, “2” indicates median, and “3” indicates both moving average and median processing. Means. Which filter processing is performed is set in the image analysis program when the operator inputs in advance from the teach pendant TP. The detection parameter 6 defines the filter window width.

（１）ロボット制御装置ＲＣは検出パラメータ５でフィルタモードを設定する。

(1) The robot controller RC sets the filter mode with the detection parameter 5.

(2) Next, the robot controller RC filters the image data according to the set filter mode with the filter window width specified by the detection parameter 6.
(3) Subsequently, the robot controller RC searches roughly for the apexes based on the sampling points (see FIG. 9). Black dots in FIG. 9 indicate sampling points at the time of distance measurement data acquisition.

(4) Then, the robot controller RC excludes data away from the apex by the detection parameter 4 or more.
(5) Next, the robot controller RC searches for a position where the detection parameter 2 is lowered from the apex. The search is started from the left end of the data shaped in (4) (hereinafter referred to as shaped data),
((Ranging data)-(Vertex-Detection parameter 2)) <Detection parameter 3
Let the point A be point A. Similarly, the search is performed from the right end of the shaped data, and the point B is obtained.

(6) Subsequently, the robot controller RC calculates the midpoint C of the points A to B.
(7) Then, the robot controller RC uses the position of the coordinate of C in the left-right direction and the coordinate of the height of the vertex in the vertical direction as a feature point.

(Calculation of feature point coordinates)
Returning to the original, the CPU 20 of the robot controller RC determines the feature point coordinates in the robot coordinates from the feature points on the image data obtained by the image processing and the robot coordinates of the search start point and the search end point. And is stored in the fourth storage area 23d of the storage unit 23 together with the physical quantity.

  Here, the feature points are obtained separately for the search direction and the laser irradiation direction. Hereinafter, the position of the feature point in the search direction is referred to as “left / right position”, and the position of the feature point in the laser irradiation direction is referred to as “up / down position”. At this time, the horizontal position and vertical position are obtained as follows.

このようにして、画像解析が終了すると、開先情報（特徴点と物理量）、及び画像解析された後の加工測距データを、ＣＰＵ２０は、ティーチペンダントＴＰに出力する。ティーチペンダントＴＰのディスプレイ４２は、その表示領域Ｄａ（図１２参照）に画像解析結果（すなわち、開先情報（特徴点と物理量）、及び画像解析された後の加工測距データ）をグラフ化して表示するとともに、表示領域Ｄｂ（図１６参照）に対して各種の物理量を表示する。なお、本実施形態では表示領域Ｄｂには、開先（レーザ）データのデータ個数も示される。

When the image analysis is thus completed, the CPU 20 outputs the groove information (feature points and physical quantities) and the processed distance measurement data after the image analysis to the teach pendant TP. The display 42 of the teach pendant TP graphs the image analysis results (that is, groove information (feature points and physical quantities) and processed distance measurement data after image analysis) in the display area Da (see FIG. 12). While displaying, various physical quantities are displayed on the display area Db (see FIG. 16). In the present embodiment, the display area Db also shows the number of groove (laser) data.

  In the display area Da, the horizontal axis indicates the moving time (seconds) of the laser displacement sensor LS, but it may be displayed by the distance (mm) moved by the laser displacement sensor LS instead of seconds.

(Reference point position)
In the initial one-way search operation, these feature points are stored as a reference point (reference position) with a file name and filed in the area Pa of the second storage area 23b. This is shown in FIG. Although FIG. 8 shows the search direction parallel to the X axis of the robot coordinate system for convenience of explanation, the actual search does not necessarily need to be parallel to the X axis.

After acquiring the reference point (reference position) in this way, the one-way search operation is similarly performed on the workpiece W to be constructed.
(Calculation of deviation)
After performing the one-way search operation as described above, the robot controller RC assigns a file name to the coordinates of the feature point stored in the fourth storage area 23d and the area Pa of the second storage area 23b first. Then, the deviation amount is calculated from the coordinates of the reference point stored as a file by the following formula, and a deviation amount correction file is created and stored in a storage area (not shown) of the storage unit 23.

本実施形態では、このようにレーザ変位センサという一次元の検出しかできないセンサで、二次元の開先情報（すなわち、特徴点および物理量）の取得を一方向サーチと同じ動作で行うことができる。なお、ここで、二次元といっているのは、Ｘ軸とＺ軸を含む平面上で前記開先情報が得られることをいっている。

In the present embodiment, the two-dimensional groove information (that is, feature points and physical quantities) can be acquired by the same operation as the one-way search by using a sensor capable of only one-dimensional detection such as a laser displacement sensor. Here, the term “two-dimensional” means that the groove information can be obtained on a plane including the X-axis and the Z-axis.

(Check image processing parameters)
By the way, in the welding robot control device 10 as the position detection system configured as described above, when the operator checks the image processing parameters after performing a one-way search operation once, the following is performed. To be done.

  The operator operates the keyboard 41 of the teach pendant TP to set the teach pendant TP to the image processing parameter adjustment mode. In the adjustment mode, the operator operates the keyboard 41 to cause the display 42 to display a parameter adjustment screen for image processing parameters corresponding to the groove shape to be adjusted. In this state, the operator operates the keyboard 41 to display image processing parameters. Adjust the input.

After that, the operator operates the keyboard 41 of the teach pendant TP to input an instruction for performing re-image analysis.
In response to the instruction to perform the re-image analysis, the CPU 20 of the robot controller RC adjusts the adjusted data stored in the area Qb of the third storage area 23c based on the distance measurement data stored in the first storage area 23a. Image analysis of the welded joint is performed according to the image processing parameters. Then, the CPU 20 assigns a file name to the image analysis data obtained according to the adjusted image processing parameter, and stores the file in the area Pb of the second storage area 23b.

  In this way, the image analysis data after adjustment of the image processing parameters (that is, groove information (feature points and physical quantities) and processed distance measurement data after image analysis) are the same as those before the adjustment of the image processing parameters. These are shown in the display area Da shown in FIG. 12 and the display area Db shown in FIG. The operator looks at the contents displayed on the display 42 and checks whether or not the image processing parameters are desired.

  In this check, a display switching key (not shown) provided on the keyboard 41 is operated to check image analysis data (that is, groove information (feature points and physical quantities) and image analysis) before image processing parameter adjustment. Then, the processed distance measurement data) may be read out from the area Pa of the second storage area 23b and switched and displayed on the display 42. With this configuration, both image analysis data before and after image processing parameter adjustment can be viewed alternately.

The keyboard 41 having the display switching key (not shown) corresponds to display switching means.
If necessary, the operator subsequently displays a parameter adjustment screen on the display 42 in the same manner, inputs and adjusts the image processing parameters, repeats the instruction for re-image analysis, and the operator checks the image processing parameters. By performing the above, a desired image processing parameter may be obtained.

  When a desired image processing parameter is obtained, the operator operates the keyboard 41 of the teach pendant TP and inputs an instruction for storing the image processing parameter. The image processing parameters adjusted and input in response to the save instruction input are output to the robot controller RC and stored in the area Qb of the third storage area 23c in the storage unit 23.

  The image processing parameters after adjustment stored in the region Qb are the detection pattern number, the data sampling cycle, and the detection parameters 1 to 9 in the example of the image processing parameter that is the V-shaped groove detection parameter shown in Table 1. Is the value of Here, in Table 1, even when the value of the detection parameter 5 is changed from “0” to “1”, only the actually adjusted detection parameter is not stored in the region Qb. All the parameters indicated by are stored in the area Qb.

It should be noted that the image processing parameters before adjustment are stored in the area Qa of the third storage area 23c of the storage unit 23.
According to the welding robot control device 10 of the present embodiment, the following effects can be obtained.

  (1) In the welding robot control device 10 of the present embodiment, the robot control device RC is provided with a storage unit 23 having a second storage area 23b (second storage means) for storing image analysis data. Further, a display 42 (display unit) for displaying image analysis data on a teach pendant TP as a portable operation means, inputs an image processing parameter, and inputs an instruction to perform re-image analysis according to the adjusted image processing parameter. A keyboard 41 (parameter input unit and re-image analysis instruction input unit) is provided.

  When there is an instruction to perform re-image analysis from the keyboard 41 (re-image analysis instruction input unit), the CPU 20 (groove information acquisition unit) of the robot control device RC stores the first storage area 23a (first) in the storage unit 23. The image analysis of the welded joint is performed in accordance with the image processing parameter that has been adjusted and input based on the distance measurement data stored in one storage means), and new image analysis data is acquired. The display 42 of the teach pendant TP displays image analysis data obtained in accordance with the image processing parameters that have been adjusted and input.

  As a result, the control apparatus 10 for the welding robot of the present embodiment teaches the image analysis results when different image processing parameters are applied based on the distance measurement data obtained by the search operation without performing the search operation thereafter. This can be confirmed on the pendant TP and can shorten the adjustment time of image processing in system introduction or new teaching.

  (2) In the control apparatus 10 for the welding robot of the present embodiment, the third storage area 23c that stores image processing parameters adjusted and input by the keyboard 41 (parameter input unit) in the teach pendant TP (portable operation means). (Third storage means) is provided.

  As a result, by providing the third storage area 23c, it is possible to store the image processing parameters adjusted and input by the keyboard 41 (parameter input unit), and re-acquire groove information using the stored image processing parameters. be able to.

  (3) In the control apparatus 10 for the welding robot of the present embodiment, the second storage area 23b (second storage means) of the storage unit 23 is an area Pa (storage area) for storing image analysis data before image processing parameter adjustment. And an area Pb (storage area) for storing image analysis data after image processing parameter adjustment.

  As a result, in the present embodiment, the image analysis data obtained according to the respective image processing parameters before and after the image processing parameter adjustment can be displayed on the display 42 (display unit) of the teach pendant TP. Image processing parameters can be easily checked.

  (4) In the welding robot control apparatus 10 of the present embodiment, the second storage area 23b (second storage means) of the storage unit 23 stores the image analysis data before and after adjustment of image processing parameters as files. I tried to do it.

  As a result, in the present embodiment, the image analysis data obtained according to the image processing parameters before and after the image processing parameter adjustment is read out on the display 42 (display unit) of the teach pendant TP by reading the file. While being able to display, it is possible to readjust image processing parameters.

  (5) In the present embodiment, the teach pendant TP (portable operation means) includes image analysis data before image processing parameter adjustment stored in each of the areas Pa and Pb of the second storage area 23b of the storage unit 23, and Any one of the image analysis data after adjusting the image processing parameters is switched and displayed on the display 42 (display unit). That is, the teach pendant TP is provided with a keyboard 41 (display switching means) having a display switching key (not shown) for switching display.

As a result, the effect of changing the image processing parameter can be confirmed.
In addition, this invention is not limited to the said embodiment, You may comprise as follows.

  In the above embodiment, when the laser displacement sensor LS performs a one-way search operation on a welded joint having a plurality of portions having different groove cross-sectional shapes, a plurality of search operations are performed for each portion having a different groove cross-sectional shape. The distance analysis data for each groove cross-sectional shape obtained by the above is subjected to image analysis according to the image processing parameters corresponding to the groove cross-sectional shape.

  At this time, when the image analysis data obtained for each groove cross-sectional shape is filed, a number as an identification code is automatically added to the beginning or end of the file name in ascending or descending order, and the storage unit 23 Is stored in the area Pa of the second storage area 23b. After this, the image processing parameters are readjusted, and when the image analysis data obtained according to the adjusted image processing parameters is filed, a number as an identification code is automatically added to the beginning or end of the file name. It adds to an ascending order or descending order, and preserve | saves with respect to the area | region Pb of the 2nd storage area 23b of the memory | storage part 23. FIG.

In addition, as for the identification code given to the file name, English symbols may be given in alphabetical order instead of numbers.
In this way, when there are a plurality of search operations in the teaching data as one program, the reproduction operation is performed, and the distance measurement data is stored in the first storage area 23a (first storage means). The image analysis data subjected to image analysis in accordance with the image processing parameters is stored in the second storage area 23b (second storage means).

  At this time, because the groove shape is different, each time the image analysis data obtained by image analysis with different image processing parameters is filed, files with different numbers or different alphabets assigned to each file A name is created.

  Thereafter, when the image processing parameters are adjusted and input with the keyboard 41 of the teach pendant TP with respect to the image analysis data obtained according to the different image processing parameters, the weld joints are adjusted according to the image processing parameters input for each file unit Image analysis can be performed.

  In the above embodiment, the image analysis data before and after image processing parameter adjustment is switched and displayed on the display 42 of the teach pendant TP. In addition to this configuration, image analysis data before and after image processing parameter adjustment may be simultaneously displayed on the display 42 as shown in FIG.

  That is, the keyboard 41 of the teach pendant TP is configured to have display mode selection keys (not shown), and the keyboard 41 is caused to function as display mode selection input means. Then, by operating the display mode selection key, as shown in FIG. 14A, the image analysis data before image processing parameter adjustment is displayed in the display area 42a of the display 42, and the display area 42b of the display 42 is displayed. The display mode for displaying the image analysis data after adjusting the image processing parameters is set. Note that the vertical positional relationship between the display areas 42a and 42b may be reversed. The display mode of each data may be a graph or a tabular format.

  In the above embodiment, the image analysis data before and after image processing parameter adjustment is switched and displayed on the display 42 of the teach pendant TP. In addition to this configuration, as shown in FIG. 14B, a display mode for displaying distance measurement data and image analysis data before and after image processing parameter adjustment on the display 42 at the same time may be provided.

  That is, the keyboard 41 of the teach pendant TP is configured to have display mode selection keys (not shown), and the keyboard 41 is caused to function as display mode selection input means. Then, by operating the display mode selection key, as shown in FIG. 14B, the distance measurement data stored in the first storage area 23a is displayed in the display area 42c of the display 42, and image processing is performed in the display area 42d. A display mode is set in which image analysis data before parameter adjustment is displayed and image analysis data after image processing parameter adjustment is displayed in the display area 42e. The display mode of each data may be a graph or a table.

  In the above embodiment, the teach pendant TP includes image analysis data before image processing parameter adjustment stored in each of the areas Pa and Pb of the second storage area 23b of the storage unit 23, and image analysis after image processing parameter adjustment. Any one of the data is switched and displayed on the display 42 (display unit).

  Instead of this configuration, one of the distance measurement data stored in the first storage area 23a and the image analysis data before image processing parameter adjustment stored in the area Pa of the second storage area 23b is selected, and these are selected. A keyboard 41 having keys for displaying data on the display 42 may be provided.

  Alternatively, one of the distance measurement data stored in the first storage area 23a and the image analysis data after image processing parameter adjustment stored in the area Pb of the second storage area 23b is selected, and these data are displayed on the display 42. You may provide in the keyboard 41 which has the key displayed on this.

In this case, the effect of the presence or absence of the image processing parameter can be confirmed.
In the above-described embodiment, the display 42 that is a display unit is not limited to a liquid crystal display, and may be configured by other displays such as an organic EL and a plasma display.

  Instead of the configuration of the above embodiment, the configuration of the conventional example shown in FIG. 16 having the laser displacement sensor control device LU may be embodied.

(A) is a block diagram of the control apparatus of the robot of one Embodiment, (b) is the schematic of the teach pendant TP similarly. (A) is explanatory drawing of a tool coordinate system, (b) is a perspective view of the laser displacement sensor LS which shows the attachment state of the laser displacement sensor LS. The block diagram of robot controller RC. Explanatory drawing of one-way search operation | movement. Explanatory drawing of the feature point and physical quantity of a V-shaped joint. Explanatory drawing of the feature point and physical quantity of a lap joint. Explanatory drawing of the procedure of the image analysis of a V-shaped joint. Explanatory drawing which shows the mode of conversion to the robot coordinate of a feature point and a physical quantity. Explanatory drawing of the image analysis of a circular arc position. Explanatory drawing which similarly demonstrates operation | movement of groove information acquisition function. (A), (b) is explanatory drawing explaining operation | movement of groove information acquisition function similarly. Explanatory drawing which displayed the image analysis result as a graph on the display of the teach pendant TP. Explanatory drawing which displayed various physical quantities on the display of teach pendant TP. (A), (b) is explanatory drawing which shows the display area of the display 42 of the teach pendant TP of other embodiment. Explanatory drawing of a one-way search function. (A)-(c) is explanatory drawing of a one-way search.

Explanation of symbols

M ... Manipulator, LS ... Laser displacement sensor, RC ... Robot controller,
TP ... Teach pendant (portable operation means),
20 ... CPU (image analysis means, groove information acquisition means)
23 ... storage unit, 23a ... first storage area (first storage means),
23b ... second storage area (second storage means), 23c ... third storage area (third storage means),
41... Keyboard (parameter input unit, re-image analysis instruction input unit, display switching unit, display mode selection input unit), 42. Liquid crystal display (display unit).

Claims (7)

A laser displacement sensor that projects laser light onto a welded joint to obtain distance measurement data, a manipulator that causes the laser displacement sensor to perform a search operation in a direction that crosses the weld line together with a welding torch, and stores the distance measurement data A groove that performs image analysis of the weld joint according to image processing parameters based on the first storage means and the distance measurement data, and acquires groove information including feature points related to the groove shape of the weld joint based on the image analysis In an automatic welding machine position detection system equipped with information acquisition means,
Second storage means for storing the groove information and processed distance data after image analysis (hereinafter referred to as groove information and processed distance data after image analysis is referred to as image analysis data);
A display unit that displays the image analysis data, a parameter input unit that adjusts and inputs the image processing parameters, and a re-image analysis instruction input unit that inputs an instruction to perform re-image analysis according to the adjusted image processing parameters. Portable operation means,
When there is an instruction to perform re-image analysis from the re-image analysis instruction input unit, the groove information acquisition unit is configured to output the image of the weld joint according to the image processing parameter that has been adjusted and input based on the distance measurement data of the first storage unit. A position detection system for an automatic welding machine, wherein analysis is performed to create new image analysis data, and the display unit displays the new image analysis data.   2. The position detection system for an automatic welder according to claim 1, wherein the portable operation means includes third storage means for storing image processing parameters adjusted and input by the parameter input unit.   The second storage means stores a storage area for storing image analysis data before input of image processing parameter adjustment (hereinafter referred to as before image processing parameter adjustment), and after input of image processing parameter adjustment (hereinafter referred to as after image processing parameter adjustment). The position detection system for an automatic welder according to claim 1 or 2, further comprising a storage area for storing the image analysis data of the automatic welder.   3. The position detection system for an automatic welder according to claim 1, wherein the second storage unit stores image analysis data before and after adjustment of image processing parameters as files. The second storage means
5. The automatic welding according to claim 4, wherein each time the image analysis data obtained by image analysis with different image processing parameters is filed, different identification codes are given to the file names of the created files. Machine position detection system.   The portable operation means includes any one of ranging data stored in the first storage means, image analysis data before image processing parameter adjustment stored in the second storage means, or image analysis data after image processing parameter adjustment. 5. The position detection system for an automatic welding machine according to claim 4, further comprising display switching means for selecting one of the data and switching and displaying the selected data on the display unit. The display unit
A display mode for displaying one of the distance measurement data stored in the first storage means, the image analysis data before image processing parameter adjustment stored in the second storage means, and the image analysis data after image processing parameter adjustment; A display mode for displaying at least two data simultaneously;
The portable operation means is provided with a display mode selection input means for selecting the display mode,
5. The position detection system for an automatic welder according to claim 4, wherein the display unit executes any one of the display modes in response to a display mode selection input by the display mode selection input means.

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