JPS6246884B2 - - Google Patents

Description

[Detailed Description of the Invention] In recent years, arc welding robots have been widely used to automate arc welding of thin steel plates, etc., and these welding robots are capable of performing point-to-point (PTP) teaching and continuous path (C .
P) Teaching playback method using playback is adopted. This PTP teaching/CP playback method memorizes so-called points (teaching points) and automatically moves the robot from the memorized points to the points.

The present invention relates to an improvement of a display control section in a control device for an arc welding robot using the teaching playback method.

Figure 1 shows an example of a general system configuration of an arc welding robot using the teaching playback method, Figure 2 shows a block diagram of its conventional control system, and Figure 3 shows a conventional screen. This is a display example.

The part surrounded by a broken line in FIG. 1 is a control device 1, which is made up of a control panel 2 and a teaching box 3. Further, the control panel 2 is provided with a keyboard switch 14 for operation and a display device 15 such as a cathode ray tube (CRT, so-called cathode ray tube), forming a man-machine interface.
Various welding conditions stored in the storage section of the control panel 2 are appropriately applied to the welding power source 4, robot body 5, and external jig 13 via cables. Welding power source 4
is connected to a wire feeding device 7 via a power cable 6, and a wire 8 fed from the wire feeding device 7 is guided to a torch 9 of the robot body 5 by a conduit cable 10. ing.

In arc welding, a torch 9 and a workpiece 1 are connected to one side of a welding power source 4 via a power cable 11.
2, welding current, welding voltage,
Control of the supply of shielding gas to the welding section, etc. is performed by the welding power source 4 based on commands from the control panel 2. The posture and movement of the torch 9 are controlled by the robot body 5 based on commands from the control panel 2. Further, the workpiece 12 is attached to an external jig 13, and the robot body 5 is a long workpiece.
External jig 13 is used for those that extend beyond the operating range of
The robot main body 5 is operated after changing the position and posture of the work by moving the robot main body 5, thereby substantially widening the operating range of the robot main body 5. Sequence control of external jigs is also based on commands from the control panel 2.

In the block diagram of FIG. 2, 16 is a central processing unit (hereinafter referred to as CPU), and 17 is a control program storage section. 18 is a position data storage unit;
The position and posture information of the taught torch is stored in correspondence with the step number. Reference numeral 19 denotes a welding work data storage unit which stores taught conditions and data for various welding works in correspondence with step numbers. 20 is CPU 16 and 17
19 and 21 to 23. 21 is an input/output control section, which controls teaching box 3 and keyboard switch 14;
controls the input and output signals of A display buffer 22 temporarily stores signals sent to the display device 15. If a total of 512 characters (16 characters vertically and 32 characters horizontally) are allocated to the screen of the display device 15, the storage capacity of the display buffer 22 will be 512 bytes. Reference numeral 23 denotes a device control section, which controls devices such as the welding power source 4, the robot body 5, and the external jig 13.

FIG. 3 shows the screen of the display section 15, and 24 is a step display section, which displays the program number corresponding to the workpiece and the step number corresponding to the teaching point. A welding work data display section 25 displays various welding conditions and data taught by the keyboard switch 14. Reference numeral 26 denotes an error display section which does not display anything during normal operation, but if there is an abnormality in the equipment or an operational error by the operator, an error display and corrective measures are briefly displayed at this position.

Next, the operation and display of the conventional arc welding robot control device configured as described above will be explained. First, there are two operating modes: teaching mode and automatic welding mode (playback operation). In the teaching mode, after specifying the program number, the robot body 5 is moved by the teaching box 3 to determine the desired torch tip position and torch attitude, and the position information is stored in the position data storage section 18 of the control panel 2. Memorize sequentially. A step number is added to this position information each time the position or posture changes, and the teaching point and step number correspond. After teaching one position along the workpiece, use the keyboard switch 14 to call up the desired program number and step number on the step display section 24 of the display device 15, and then display the various welding work conditions necessary for each step. Enter. The various input welding work conditions are stored together with the step numbers in the welding work data storage section 19 in the teaching order, and are simultaneously sent to the display buffer 22 where they are temporarily stored and displayed in the welding work data display section 25 of the display device 15.
are displayed in the order they were taught. After position teaching and welding work teaching are completed, the stored data is called back to the screen to check and correct whether it is correct or not. If there is a mistake, switch the keyboard switch 1.
Modified by 4. Check on the screen of the display device 15.
After making any corrections, test drive the robot at low speed and make a final check to make sure there are no errors in teaching.

When the teaching is finished, the mode is switched to automatic welding mode, and the robot is operated automatically for welding using a start switch (not shown). During automatic welding operation, the torch 9 automatically operates between teaching points under taught welding work conditions. CPU16
processes and executes conditions and data in the order in which they are taught, that is, in the order in which they are displayed on the display device.
Further, welding work conditions and data corresponding to the teaching point at which the torch 9 is currently operating are sequentially displayed on the screen of the display device.

The conventional arc welding robot operates and displays as described above, and if we look at the screen shown in FIG. 3, the sequence of operations is as follows. In the example of FIG. 3, in step 150 of program number 4, the moving speed (F) is set to 1234 mm/min, the welding voltage (v) is set to 12.3 V, and the welding current (I) is set to 123 A.
, and in that state run timer T2 (actor flow) for 1.2 seconds. After setting the wire feeding speed (W) to 12cm/min, turn off the arc, wait for the input 12 of the external jig synchronization signal to turn on, and then reset the output 34 of the external jig synchronization signal (set it to 0). )do. Then, wait for the general-purpose timer (D) to operate for 3.5 seconds and input the external jig synchronization signal 56.
If it is on, it indicates to jump to step 160.

As described above, in the conventional device, various welding conditions corresponding to teaching points are stored, displayed, and processed in the teaching order.

However, even when considering welding conditions, in the case of an arc welding robot, there are two types of data: data specific to the welding operation and data for sequentially controlling the robot components. Data specific to welding operations include the moving speed of the torch tip (F), arc on/off signal, welding voltage (V),
There are welding current (I), wire feeding speed (W), continuous/intermittent wire feeding (WF), welding timer (pre-flow T1, after-flow T2, wire feeding waiting T3, torch movement waiting T4), etc.

(Hereinafter referred to as modal data) Data for sequential control includes, for example, a jump command (JMP) for skipping a certain step and moving to a specified step, and an external jig 1.
3 and the operation of the robot body 5, external jig synchronization signals (JIG IN, JIG OUT), and a general-purpose timer (D: dwell) to temporarily stop the operation of the robot body, etc. . (hereinafter referred to as sequence data) In this way, although there are always two types of welding conditions, conventional methods simply store, display, and process them in the order of teaching, and modal data unique to welding operations. However, since the sequence data that should be taught and displayed is mixed and displayed in the processing order, it is difficult to set the conditions, and in particular, it takes a long time to check and correct the data after teaching. Ta. Particularly when the number of steps exceeds several hundred, this problem becomes so severe that it takes a whole day to teach, and sometimes the welding conditions are taught incorrectly, resulting in damage to expensive workpieces. Furthermore, if the synchronization signal with the external jig 13 is incorrectly set, the external jig 13 and the robot body 5 may each operate independently, and in extreme cases, they may collide, resulting in a serious accident.

This invention was made in order to reduce the drawbacks of the conventional device as described above.Modal data specific to welding work is displayed at a fixed display position on the screen at once, and sequence data is displayed in the processing order, that is, taught. The object of the present invention is to provide a control device for an arc welding robot that makes teaching easy, reduces teaching errors, and makes it easy to confirm and modify teaching data by displaying data sequentially and simultaneously.

An embodiment of the present invention will be described below with reference to FIGS. 4 and 5. FIG. 4 is a block diagram of a control system showing one embodiment of the present invention. 4, the difference from the conventional example shown in FIG. 2 is that a display buffer 22, 28 control buffers, 2
The system is divided into 9 modal data buffers and 30 sequence data buffers, and is further provided with 27 display device control units. The display device control section 27 classifies the display data to be sent to the display device 15 into control data, modal data, and sequence data after identification, and stores them in a control data buffer, a modal data buffer, and a sequence data buffer, respectively. The control buffer stores data such as program numbers, step numbers, and abnormality displays. The modal data buffer stores modal data specific to welding work, but the position where each data should be stored is fixed. The sequence data buffer stores sequence data, but the position where each piece of data should be placed is not fixed, and is stored in the order in which it is sent.

FIG. 5 shows a display section 1 in an embodiment of the present invention.
This is the screen of No. 5. 5 differs from FIG. 3 in that the welding work data display section is divided into a modal data display section 31 and a sequence data display section 32. The modal data display section 31 displays data specific to welding work, but the position where each data is displayed is a fixed position as shown in the figure.
Always displayed at each step. The sequence data display section 32 displays various welding work condition data input in that step, but the position of each data to be displayed is not fixed and is displayed in the order in which it was input. If there is no input data at that step, the modal data of the previous step is displayed as is on the modal data display section 31, and nothing is displayed on the sequence data display section 32.

4 and 5, the data in the control data buffer 28 is displayed on the step display section 24 and the error display section 26, the data on the modal data buffer 29 is displayed on the modal data display section 31, and the data on the sequence data buffer 29 is displayed on the modal data display section 31. 30 data are displayed on the sequence data display section 32.

In the embodiment configured as described above, the operations and displays at certain arbitrary steps are as follows. First, an arbitrary step number that has been taught in advance in correspondence with the position information is called up on the step display section 24 of the screen together with the program number using the keyboard switch 13. Next, various welding work conditions are sequentially input using the keyboard switch 13. The input various welding work data are stored in the welding work data storage section and sent to the display device control section 27. If the data sent to the display device control unit 27 is modal data, it is stored in a predetermined position in the modal data buffer, or
Alternatively, the previously stored data is rewritten and displayed at a predetermined position on the modal data display section 31. At the same time, the data are also stored in the sequence data buffer in order from the beginning, and are displayed in order from the bottom of the sequence data display section 32. In the case of sequence data, the sequence data buffer,
This data is also stored sequentially after the previous data.
Sequence data can be specified repeatedly within the same step, and the specified order becomes the execution order. For modal data that was not input in that step, the data in the previous step is displayed as is.
If there is no input data at that step, the modal data of the previous step is displayed as is, and nothing is displayed on the sequence data display section 32. Therefore, when checking and correcting data specific to welding work, it is only necessary to look at the modal data display section 31, and to see in which step the data was input, go back through the steps in order and check the sequence data display section. 32, and the sequence data display section 32 for steps that have not been inputted is blank, making it extremely easy to check. In addition, in order to check how the sequence is going at that step, only the data input at that step is displayed on the sequence data display section 32, making it extremely easy to check and modify. By the way, the fifth
The meaning of the screen shown in the figure is as follows. In program number 4, step number 150, set the moving speed (F) of the torch tip to 1234 mm/min, then turn on the welding current.
Set to 123A, operate welding timer T2 for 1.2 seconds, and then turn off the arc. Next, read the external synchronization signal input 12, wait for it to turn on, and reset the external jig synchronization signal output 34 (set to 0).
to). After that, the general-purpose timer (D) is operated for 3.5 seconds, and if the external jig synchronization signal input 56 is on, the process jumps to step 160, and the torch tip moves in a straight line to the position of step 160. ing. Other welding conditions are the same as the previous step (step number 149), the welding voltage is 12.3V, the wire feeding speed is 12cm/min, the wire feeding is continuous,
Welding timer T1 is 1.1 seconds, T3 is 1.3 seconds, and T4 is 1.4 seconds.
This shows that it remains in seconds.

In FIG. 4, the display device control section 27 may be composed of a data decoder, a data distributor, etc., and a control program storage section stores the decoder and distribution programs, so that the CPU
may process and store data directly in each buffer.

As described above, according to the present invention, teaching is facilitated by displaying modal data specific to welding work all at once with a fixed display position on the screen, and displaying sequence data simultaneously in processing order, that is, teaching order. It is possible to obtain a control device for an arc welding robot in which teaching errors are reduced and teaching data can be easily confirmed and corrected.

[Brief explanation of the drawing]

Figure 1 shows the system configuration of a teaching playback type arc welding robot, Figure 2
The figure is a block diagram showing a conventional control system, and FIG. 3 is a diagram showing an example of a screen display in the conventional example. FIG. 4 is a block diagram showing a control system of an embodiment of the present invention, and FIG. 5 is a diagram showing an example of a screen display of this embodiment. In addition, in the figure, 1 is a control device, 2 is a control panel,
3 is a teaching box, 4 is a welding power source, 5 is a
is the robot body, 6 is the power cable, 7 is the wire feeder, 8 is the welding wire, 9 is the torch,
10 is a conduit cable, 11 is a power cable, 12 is a workpiece, 13 is an external jig, 14 is a keyboard switch, 15 is a display device, 16 is a central processing unit, 17 is a control program storage section, and 18 is a position data storage section. , 19 is a welding work data storage unit;
20 is a common bus bar, 21 is an input/output control section, 22 is a display buffer, 23 is a device control section, 24 is a step display section, 25 is a welding work data display section,
26 is an error display section, 27 is a display device control section, 2
8 is a control buffer, 29 is a modal data buffer, 30 is a sequence data buffer,
31 is a modal data display section, and 32 is a sequence data display section.

Claims (1)

[Claims] 1. In an arc welding robot control device that memorizes points as appropriate, automatically moves the robot from the memorized points to the points, and simultaneously displays various welding conditions corresponding to these points on a display device. , a modal data buffer in which condition data specific to welding work is stored in a fixed location, and a sequence data buffer in which data to sequentially control the robot's operations is stored in the order in which it is input; The data sent to the display device is classified into modal data and sequence data, and the modal data is displayed all at once at a fixed position on the display device via the modal data buffer, and the sequence data is displayed at a fixed position on the display device via the modal data buffer. A control device for an arc welding robot, comprising a control section that displays data in the order taught in the steps, at a separate position from a modal data display section on a display device via a front door.