JP5670147B2 - Arc welding robot controller - Google Patents

Description

  The present invention relates to an arc welding robot control device.

  Conventionally, when a tool tip position of a manipulator is manually operated by jog feed, the manual operation is performed after an operator selects a reference manual operation coordinate system in advance using a teaching operation device.

Known types of manually operated coordinate systems include a base coordinate system, which is a coordinate system fixed to a manipulator, and a tool coordinate system having an axial direction corresponding to the posture of the tool.
Since the axial directions of the above-mentioned machine coordinate system, tool coordinate system, and the like are not directions according to the shape or work area of the workpiece, there is a problem that the operation of moving in a desired direction is complicated even during manual operation. .

  Therefore, a manual operation coordinate system called a user coordinate system that allows the operator to determine a desired axial direction so that the axial direction during jog feeding is the axial direction according to the shape and work area of the workpiece. Is known (see, for example, Patent Document 1).

  In this patent document 1, it is detected that the tool tip position of the manipulator has entered a predetermined area which is a work area by the following two methods. One method is a method in which a photoelectric sensor is arranged in a predetermined region, and the position of the tool is detected by the photoelectric sensor. Another method is a method of detecting the position of the tool based on the current position from the encoder of the servo motor that drives the joint of the manipulator by predetermining the work area with the coordinate value data.

  And in patent document 1, it is comprised so that the manual motion coordinate system according to the said predetermined area | region may be selected automatically.

JP 2009-110190 A, paragraph 0039

  By the way, when applying patent document 1 to an arc welding robot, it is desirable to set the welding line coordinate system according to the said area, when a torch is moved on a welding line at the time of a check driving | operation. The check operation is a low-speed regeneration operation performed for teaching confirmation. If the welding line coordinate system corresponding to the section is set when the torch is moved on the welding line as described above, there is an advantage that the work is facilitated when the operator performs fine adjustment.

Alternatively, it may be desirable to automatically set a predetermined user coordinate system during the check operation. However, Patent Document 1 does not consider such operation.
The object of the present invention is to select a coordinate system for teaching correction by automatically setting an optimum manual operation coordinate system according to the teaching target such as the welding environment or the teaching contents of the working program when teaching or correcting the working program. An object of the present invention is to provide an arc welding robot control device that can reduce operations required for the above.

In order to solve the above problems, the invention of claim 1 is directed to an arc welding robot control apparatus for jogging and feeding a manipulator having a torch according to a manual operation coordinate system by operating manual operation means. Includes a weld line coordinate system, the storage means for storing the weld line coordinate system in association with an arc welding section defined by a work program in which work contents of the manipulator are stored, and the torch in the arc welding section. The gist of the present invention is an arc welding robot control device comprising coordinate system automatic setting means for automatically setting the welding line coordinate system as the manual operation coordinate system when positioned .

According to a second aspect of the present invention, in the first aspect , when the coordinate system automatic setting unit automatically sets the weld line coordinate system as the manual operation coordinate system, the set weld line coordinate system is provided to an operator. An informing means for informing is provided.

As described above in detail, according to the first aspect of the invention, when the torch is positioned in the arc welding section defined by the work program, the operation necessary for selecting the coordinate system is automatically set in the weld line coordinate system. Can be reduced.

According to the invention of claim 2 , when the coordinate system automatic setting means automatically sets the welding line coordinate system as the welding line coordinate system , the notification means can notify the operator of the setting.

The block diagram of the arc welding robot control apparatus which employ | adopted the teaching playback system of one Embodiment which actualized this invention. The block diagram of a robot control apparatus. Explanatory drawing of a weld line coordinate system (user coordinate system). Explanatory drawing of a weld line coordinate system (user coordinate system). Explanatory drawing of table coordinate system Cw (user coordinate system). The flowchart at the time of reproducing a work program and performing check operation. The figure which shows correlation with a work program and a user coordinate system. The figure which shows the data structure in a work program. The figure which shows the correlation of station data and a user coordinate system. The figure which shows the correlation of positioner data and a user coordinate system.

Hereinafter, an embodiment of an arc welding robot control apparatus embodying the present invention will be described with reference to FIGS.
An arc welding robot control device (hereinafter simply referred to as a robot control device) RC shown in FIG. 1 has six axes (that is, 6 axes) that perform welding work so that arc welding is automatically performed on the workpiece W on the work table 16. The manipulator 10 of each joint axis) is controlled. In the figure, as an example, only one work table 16 is shown, but a plurality of work tables are usually installed. Further, the work table 16 may be a work table fixed to the floor on which the work W is simply installed, or may be a positioner for maintaining the welding posture with respect to the work W optimally. When a positioner is adopted as the work table 16, the axis of the positioner is driven and controlled by the robot controller RC.

  Further, the work table 16 or the positioner is generally collectively referred to as a work station. Hereinafter, unless specifically distinguished from the workbench 16 or the positioner, they are collectively referred to as a work station (or simply a station).

  The manipulator 10 includes a base member 12 fixed to a floor or the like, and a plurality of arms 20 connected to the base member 12 via the plurality of joint shafts. A welding torch (hereinafter simply referred to as a torch) T is provided at the distal end portion of the arm 20 located on the most distal side. The torch T 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. Weld the workpiece W. Each arm 20 is configured to be able to move the torch T in translation and rotation by driving each drive motor (not shown). The joint angle of each arm is detected from an encoder (not shown) directly connected to the motor (not shown).

  A teach pendant TP as manual operation means is connected to the robot controller RC. On the operation surface of the teach pendant TP, a display device 30 including a liquid crystal display and various keys are provided. The teach pendant TP is a device for an operator to teach the operation of the manipulator 10.

  The keys include a plurality of button groups 40 for operating the manipulator 10, a storage key 40a, an execution key (not shown), and a mode switching key 40b. By operating these buttons or keys, key-input data or various types of information can be stored in the storage unit 56 (see FIG. 2) provided in the robot control device RC.

  As shown in FIG. 1, the button group 40 is equipped with a plurality of buttons corresponding to the directions (± X, ± Y, ± Z) of the coordinate system. When any button of the button group 40 is pressed, the manipulator 10 moves in the direction corresponding to the button. For example, when the robot controller RC moves the manipulator 10 under the set coordinate system, when the X + button of the button group 40 is pressed, the manipulator 10 moves in the X + direction of the set coordinate system. To do.

  As described above, the operator operates the button group 40 to move the manipulator 10 to a desired position to teach or correct a teaching path on the working path, that is, a teaching point on the working path. . The taught work route is stored in the storage unit 56 as a work program.

  As shown in FIG. 2, the robot controller RC includes a CPU (central processing unit) 50, a rewritable EEPROM 52 that stores control software for controlling the manipulator 10, a RAM 54 that serves as a work memory, and work programs and manual operation coordinates. A storage unit 56 comprising a rewritable nonvolatile memory for storing system definition parameters and the like is provided. The robot controller RC includes a servo driver 58 that controls the motor of the manipulator 10, and drives the manipulator 10 based on current position information (that is, a joint angle) from the encoder (not shown) according to the work program. It is possible to drive the motor to move the torch T to the teaching point and change the posture.

The robot controller RC is also electrically connected to a host controller (not shown), and can receive various external input signals from the host controller.
The CPU 50 corresponds to coordinate system automatic setting means and notification means. The storage unit 56 corresponds to a storage unit.

<About manual operation coordinate system>
First, the coordinate system used in this embodiment will be described.
(1. Base coordinate system Cb)
The base coordinate system Cb is a coordinate system unique to the manipulator 10 as shown in FIGS. In the base coordinate system Cb, the origin Ob is set to the reference position of the manipulator 10, and a horizontal plane parallel to the base bottom surface of the manipulator 10 when the manipulator 10 is installed on the ground is set as a reference plane Xb-Yb. A right-handed orthogonal coordinate system in which the direction from Xb-Yb toward the manipulator 10 is the Zb axis. As a result, the base coordinate system Cb has an origin Ob and an axial direction (Xb, Yb, Zb).

(2. Table coordinate system Cw)
The table coordinate system Cw is a user coordinate system, that is, a manual operation coordinate system, and is set with reference to the work placement surface 16a of the workbench 16 as shown in FIG. 5, and the origin Ow and the axial directions (Xw, Yw, Zw) is a right-handed orthogonal coordinate system.

When defining the table coordinate system Cw, three feature points P1, P2, and P3 on the workpiece placement surface 16a are designated.
(3. Welding line coordinate system Cr)
As shown in FIG. 3, the weld line coordinate system Cr is a user coordinate system, that is, a manual operation coordinate system, and is a coordinate system calculated based on the teaching points P4 and P5 in the arc welding section on the workpiece W. There is a right-handed orthogonal coordinate system having an origin Or and an axial direction (Xr, Yr, Zr).

  Here, the welding line (welding progression direction) has a plurality of arc welding sections, and the welding progression direction of the welding line in the arc welding section is different from the welding line progression direction of the welding line in another adjacent arc welding section. In this case, in this embodiment, for the sake of convenience of description, a positive integer of n = 1, 2, 3,.

  In addition, as shown in FIG. 4, the welding line is in adjacent sections such as the first section of the teaching points S1 and S2, the second section of the teaching points S2 and S3, and the third section of the teaching points S3 and S4. The welding line traveling direction may be different.

  In this case, in the first section, a weld line coordinate system Cr1 is defined in which the teaching point S1 is the origin Or1 and the welding line between the teaching points S1 and S2 is the Zr1 axis. In the second section, a weld line coordinate system Cr2 is defined in which the teaching point S2 is the origin Or2 and the welding line between the teaching points S2 and S3 is the Zr2 axis. In the third section, a welding line coordinate system Cr3 is defined in which the teaching point S3 is the origin Or3 and the welding line of the teaching points S3 and S4 is the Zr3 axis.

  In the present embodiment, the base coordinate system Cb, the table coordinate system Cw, and the weld line coordinate system Cr correspond to a manual operation coordinate system. As the manual operation coordinate system, a tool coordinate system that depends on the torch posture, a workpiece coordinate system that depends on the posture of the positioner, and the like are also included in the manual operation coordinate system, but the description is omitted in this embodiment. .

<Association between manual operation coordinate system and teaching target>
Next, a method for associating the manual operation coordinate system with the teaching target will be described. The teaching object described here is a work program in which work contents of the manipulator 10 are stored, an arc welding section stored in the work program, or a work station (work table 16 or positioner) in which the work W is installed.
<1. Association with work program>
A case where a manual operation coordinate system is associated with a work program will be described.

  As shown in FIG. 7, the association between the work program and the manual operation coordinate system is stored in a table format in the storage unit 56. That is, manual operation coordinate systems 00A to 00C respectively associated with the work programs 001 to 003 are stored in a table format. For example, when confirming the operation of the created work program 001, the associated manual operation coordinates System 00A is automatically selected.

The following method may be adopted as another method of association.
Each work program includes a header part 60 and a data part 70 as shown in FIG. In the header part 60, a program name and a comment are described. The data portion 70 describes teaching points on the work path, various commands executed at each teaching point, various parameters of the commands, and the like. The header 60 described above is configured so that a manual operation coordinate system associated with the work program can be stored. This associates the work program with the manual operation coordinate system.

That is, when one of the work programs 001 to 003 is selected by the worker, for example, when confirming the operation of the created work program, the manual operation stored in the header section 60 of the selected work program. Any one of the coordinate systems 00A to 00C is automatically selected.
<2. Association with arc welding section>
Next, a case where a manual operation coordinate system is associated with the arc welding section will be described. FIG. 8 shows the data structure of the work program. As shown in the figure, the work program includes a header part 60 and a data part 70. In the header part 60 of this example, a program name and a comment are described.

The arc welding section is a section surrounded by an arc welding start command AS and a welding end command AE stored in the data section 70 on the work program.
As shown in FIG. 8, the association is performed by setting the manual operation coordinate system as one of the parameters of the arc welding start command AS. The manual operation coordinate system in the arc welding section is generally the weld line coordinate system Cr, but is not limited and may be another coordinate system such as a table coordinate system Cw. That is, when confirming the operation of the created work program, the work program is selected by the worker, and while the torch T is positioned in the arc welding section, the work program is stored in the coordinate system storage area. A manually operated coordinate system is automatically selected. In FIG. 8, S1 to Sn are teaching points, and position and orientation coordinate values are described. “MOVE” is a move command. “LINE” is a linear interpolation command.
<3. Association of work stations (workbench 16 or positioner)>
Next, a case where a manual operation coordinate system is associated with the work table on which the workpiece W is installed will be described.

  As shown in FIG. 9, station numbers 001 to 003 for identification are assigned in advance to the work table, and the association between the station number and the manual operation coordinate system is stored in a table format in the storage unit 56. This is possible. The worker calls a dedicated menu and registers the manual operation coordinate system to be associated with the work station in the storage unit 56 in a table format.

  That is, when the worker teaches the work W on the work table, the associated manual operation coordinate system is automatically selected by selecting the work station as the teaching target.

  The same applies when the work station is a positioner. That is, as shown in FIG. 10, positioner numbers 001 to 003 for identification are assigned in advance to the positioner, and the association between the positioner number and the manual operation coordinate system is stored in a table format in the storage unit 56. This is possible.

  The selection of the teaching target described above is performed by the operator performing a selection operation on a selection menu on the display screen of the display device 30 of the teach pendant TP, or an external signal input from the host controller to the robot control device RC.

(Function)
<1. When manual operation coordinate system is associated with work program>
Now, in the robot control device RC configured as described above, the operation when the operation program is checked is described with reference to the flowchart of FIG.

  The check operation is executed by selecting a work program to be checked and switching to the check operation mode by the mode switch key 40b of the teach pendant TP shown in FIG. 1 or based on an input signal from a host controller (not shown). Is done. An input signal from the host controller corresponds to an input signal from the outside.

During the check operation of the work program, the position and orientation control of the manipulator 10 is executed at a slower speed than when welding is performed.
Each processing step of the work program describes a position / orientation coordinate value indicating a teaching point and various commands such as welding start and welding end performed at the teaching point. During the check operation, the position / orientation control of the manipulator 10 is performed in sequence order based on the position / orientation coordinate values of the teaching points described in each processing step. In the following description, for convenience of description, it is expressed simply as “move to teaching point” including position and orientation control.

This will be specifically described below.
When the work program is selected in step T10 and is switched to the check operation mode by the mode switching key 40b shown in FIG. 1, the CPU 50 automatically selects the manual operation coordinate system associated with the selected work program in step T20. To choose. Further, the CPU 50 outputs a signal indicating that the manual operation coordinate system associated with the selected work program is set to the teach pendant TP. The CPU (not shown) of the teach pendant TP displays that on the display device 30 based on the output signal indicating that the manual operation coordinate system is set. As a result, the operator can know the manual operation coordinate system set by looking at the notification content displayed on the display device 30.

In step T30, the CPU 50 executes one processing step in the work program. By this process, the torch T of the manipulator 10 moves to the teaching point.
In step T40, when the mode is switched to the teaching correction mode by switching the mode switching key 40b by the operator, the process proceeds to step T50. If the mode switch key 40b is not switched, the process proceeds to step T70.

  In step T50, the operator performs jog feed using a plurality of buttons related to ± X, ± Y, ± Z of the teach pendant TP under the manually operated coordinate system that is set and notified, and manipulator 10 Operate to correct the teaching point position.

  When the memory key 40a shown in FIG. 1 is operated, the CPU 50 corrects the position of the corrected manipulator 10 based on the current position information (that is, the joint angle) from an encoder (not shown) and the like. Process. Thereafter, when the operator operates a correction end button (not shown) of the teach pendant TP again, the CPU 50 makes a determination of “YES” in Step T60, and proceeds to Step T70. If the operator does not operate a correction end button (not shown) of the teach pendant TP, step T50 is continued.

  In step T70, the CPU 50 determines whether all processing steps of the work program have been completed. If all the processing steps have not ended, the CPU 50 determines that the check operation has not ended and returns to step T30.

In addition, if all processing steps of the work program have been completed, the CPU 50 terminates this program, assuming that the check operation has been completed.
In the robot controller RC, when the teaching data of the work program is corrected in the check operation mode, if the welding line coordinate system is associated with the work program as the manual operation coordinate system, the welding line coordinate system is automatically set. Is done. For this reason, when the operator jogs the manipulator 10 with the teach pendant TP to correct the teaching data, the operator can jog the manipulator 10 under the automatically set welding line coordinate system.

  In the robot controller RC, when the teaching data of the work program is corrected in the check operation mode, the table control system Cw shown in FIG. 5 is automatically associated with the work program as a manual operation coordinate system. A table coordinate system Cw is set. For this reason, when the operator jogs the manipulator 10 with the teach pendant TP to correct the teaching data, the operator can jog the manipulator 10 under the automatically set table coordinate system Cw.

<2. When manual operation coordinate system is associated with arc welding section of work program>
Next, as shown in FIG. 8, a case where a manual operation coordinate system is associated with an arc welding section described in a work program will be described.

In this case, the work program to be checked is selected in the above <1. When the manual operation coordinate system is associated with the work program>
And, for example, as shown in FIG. 4, when the welding line coordinate systems Cr1 to Cr3 are respectively associated with the first to third sections, the welding line coordinate systems Cr1 to Cr1 at the respective teaching points S1, S2 and S3. Cr3 is automatically set. Therefore, at each teaching point, when the operator jogs the manipulator 10 with the teach pendant TP to correct the teaching data, the welding line coordinate systems Cr1 to Cr3 set automatically at each teaching point. The manipulator 10 can be jog-fed to the next S2, S3, S4.

  In this case, when each teaching point is switched to the teaching correction mode by switching the mode switching key 40b by the operator, the welding line coordinate system Cr1 to Cr3 associated with the position and orientation coordinate value of the teaching point is set. A signal indicating that the setting has been made is output. The CPU (not shown) of the teach pendant TP displays that on the display device 30 based on the output signal indicating that the welding line coordinate system Cr1 to Cr3 is set. As a result, the operator can know the welding line coordinate systems Cr <b> 1 to Cr <b> 3 set by looking at the notification content displayed on the display device 30.

<3. When the work station identification number is associated with the manual operation coordinate system>
In this case, as shown in FIGS. 9 and 10, a case will be described in which the identification number of the work station (work bench or positioner) is associated with the manual operation coordinate system.

  In this case, when the worker teaches the workpiece W on the work station, the storage unit can be selected by selecting the work station as a teaching target by the teach pendant TP or by an external signal from the host controller. At 56, the manually operated coordinate system associated in a table format is automatically selected. When the selection is made as described above, a signal indicating that the selected manual operation coordinate system has been set is output. The CPU (not shown) of the teach pendant TP displays that on the display device 30 based on the output signal indicating that the manual operation coordinate system is set. As a result, the operator can know the manual operation coordinate system set by looking at the notification content displayed on the display device 30.

Now, according to this embodiment, there are the following features.
(1) The robot controller RC of the present embodiment uses a table coordinate system Cw and a weld line coordinate system Cr (manual operation coordinate system) for manually operating the manipulator 10 as a work program or an arc stored in the work program. A storage section 56 (storage means) is provided that stores a work section in which a work W, which is a welding section or a workpiece to be processed, or a positioner (teaching target) for mounting the work W is associated with the work program. The robot controller RC also includes a teach pendant TP (manual operation means) for manually operating the manipulator 10 when correcting the teaching of the work program. The robot controller RC also includes a CPU 50 (coordinate system automatic setting means) that automatically sets a table coordinate system Cw or a welding line coordinate system Cr (manual operation coordinate system) associated with the work program at the time of teaching correction. The CPU 50 controls the manipulator 10 with the set table coordinate system Cw or the welding line coordinate system Cr (manual operation coordinate system) when there is an operation command by the teach pendant TP at the time of teaching correction as the control means.

  As a result, according to the present embodiment, when the teaching of the work program is corrected, the optimum coordinate system is automatically set according to the teaching data or the welding section, so that it is not necessary to select a coordinate system in teaching correction, and teaching It is possible to reduce operations necessary for selecting the coordinate system in the correction.

  (2) In the present embodiment, the weld line coordinate systems Cr1 to Cr3 are included as the manual operation coordinate system. Then, the CPU 50 (coordinate system automatic setting means) of the robot controller RC automatically sets the welding line coordinate system when the torch T enters the arc welding section defined by the work program. As a result, when the torch T enters the arc welding section defined by the work program, the welding line coordinate system can be automatically set.

  (3) In this embodiment, when the CPU 50 (coordinate system automatic setting means, notification means) of the robot controller RC automatically sets the welding line coordinate system, the setting is changed to the teach pendant TP (manual operation means). Inform the operating operator. As a result, when the CPU 50 of the robot controller RC automatically sets the welding line coordinate system, the operator can know that the welding line coordinate system has been set. As a result, the operator can perform manual operation of the manipulator 10 with peace of mind under the set coordinate system.

In addition, you may change embodiment of this invention as follows.
In the above embodiment, the manual operation coordinate system is the table coordinate system Cw and the weld line coordinate system Cr, but is not limited to this, the tool coordinate system that depends on the torch posture, and the work coordinates that depend on the posture of the positioner The system may be a world coordinate system that is an absolute reference.

  In the embodiment, the CPU 50 of the robot control device RC notifies the display device 30 of the teach pendant TP that the user coordinate system has been set, but the user coordinate system has been set by the speaker. You may make it alert | report.

10 ... Manipulator,
50 ... CPU (coordinate system automatic setting means and notification means),
56 ... Storage unit (storage means), RC ... Robot control device,
RC: Arc welding robot controller,
TP ... Teach pendant (manual operation means), T ... Torch, W ... Workpiece,
Cr, Cr1, Cr2, Cr3 ... Welding line coordinate system.

Claims (2)

In the arc welding robot control device that jogs the manipulator including the torch according to the manual operation coordinate system by operating the manual operation means,
The manual operation coordinate system includes a weld line coordinate system,
Storage means for storing the welding line coordinate system in association with an arc welding section defined by a work program in which work contents of the manipulator are stored ;
A coordinate system automatic setting means for automatically setting the welding line coordinate system as the manual operation coordinate system when the torch is positioned in the arc welding section ;
An arc welding robot control device comprising: When the coordinate system automatic setting means is automatically set the welding seam coordinate system as the manual operation coordinate system, wherein characterized in that it comprises a notifying means for informing the operator of the welding seam coordinate system set Item 2. The arc welding robot controller according to item 1 .

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