JPS60104637A - Controlling method of industrial robot - Google Patents

Abstract

PURPOSE:To aim at restraining the lowering of a production efficiency due to abnormality, to a minimum, by judging whether the registering of abnormality is present or not in the next working step each time a machining apparatus returns to a reference position so that if the working step is jumped over this step and there is shifted to the step next to this step. CONSTITUTION:During welding of a workpiece W2 on a line 2 when a mantle 11a approaches an abnormal projection (t) on the workpiece W2 on the way of movement of a torch 11 from the starting point P2s of welding to the terminal point P2e of welding, electrical communication is established between the mantle 11a and the abnormal projection (t) so that electrical discharge takes place. Further, a detecting circuit 20b detects changes in voltage and current, and a detection output circuit 20d issues a signal indicating electrical communication to a control means 14. Accordingly, an instruction for interrupting the welding is issued to stop the torch 11 at a position P2i where the abnormality takes place, and to change over a switch 19d to a sensor electrical power source 19b. Further, electrical feed to an electrode 13 is ceased accompanied with the stopping of rotation of a feed roller 17, resulting in energization of an alarm to register the abnormality on the line 2. Further, under backtracking instruction the torch 11 moves back to a reference point P0, and welding to a workpiece W3 on a line 3 is initiated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control method for an industrial robot that is shared by a plurality of processing lines.

In general, industrial robots immediately stop processing work in the event of an abnormality in the workpiece, a temporary collision between the processing tool and the workpiece due to a teaching error (i.e., forgetting to teach the welding point), or other abnormalities such as a malfunction in the processing line. ing.

However, if an industrial robot is shared by multiple machining lines and performs machining work in sequence, if there is a problem like the one described above on one machining line, all machining lines will stop operating. This will result in a huge +13 decrease in production capacity.

In view of the above-mentioned 1iV, the present invention sets a reference point to which the processing tool of an industrial robot returns every time the processing work in each processing line is completed, and the control means is connected to the processing line and/or the workpiece. If this occurs, register abnormal fermentation on this processing line, and each time the processing equipment returns to the reference point, determine whether or not there is an abnormality registered on the processing line that should start processing from now on, and if there is an abnormality registered, The special feature is to instruct the robot to skip over that processing line and move to the next processing line, so that even if there is a problem on one processing line, it will not affect the operation of other processing lines. The purpose of this invention is to provide a control method for an industrial robot that is shared by multiple processing lines, with the aim of minimizing the decline in production efficiency due to abnormal conditions.

Prior to a detailed explanation of the present invention, a processing line and a welding robot as an industrial mouth hot welding robot, which are the background of the present invention, will be explained.

In Figure 1, 1 fist 2 and 3 are rectangular loop-shaped processing lines (hereinafter referred to as lines 2 and 3), each consisting of a roller conveyor, and the corners where three lines 2 and 3 approach each other. Processing station 1a, 2a, 3
Electricity is installed as A, and a plurality of pallets 4 and 506 are intermittently transported along the lines 2 and 3, respectively. In each line 1, 2, and 3, when the roller conveyor stops intermittently, the processing station 1a.
Unwelded workpieces W1, W2, and W3 are automatically or manually loaded onto FJIJ pallets 4, 5, and 6, respectively, at the workpiece loading location (not shown) set downstream in the transfer direction from 2a and 3a, and then Processing station la/2a
・The multi-jointed welding robot 7 installed at the midpoint of
Work W1 loaded on pallets 4, 5, and 6 distributed to a
・Automatic welding is performed on W2 and W3, and the welded workpieces W1 and W are delivered to the workpiece unloading location (not shown) set downstream from processing stations 1a, 2a, and 3a in the transport direction, respectively.
2 and W3 are taken out from pallets 4, 5, and 6, and the empty pallets 4, 5, and 6 are placed in the +iiJ work loading area again.

8, 9, and 10 are the processing stations 1a and 2, respectively.
With a locking device consisting of an air cylinder installed in a.3a, the rod is extended to the pallet4.
Each pallet is positioned and fixed by fitting into holes (not shown) provided in the 1z recesses of Nos. 5 and 6. Also, Valley Rock'AL & 8, 9, 10 is pallet 4-
It is equipped with a pallet 1 non-detector (not shown) which contacts 5-6 and detects the T here.

The multi-jointed welding port hot 7 in djJ uses a welding torch 11 (hereinafter referred to as the torch 11) as a processing tool on the final +III vertical axis. 12 is a power supply device for applying voltage to the electrode 13 etc. of the torch 11 and supplying current;
14 is MiJ Ride 2 and 3, rat contact robot 7,
and QC'-α source equipment@12 etc., a control means built in a microcomputer to control the integrated circuit 11; 15 is the iM
With the remote control panel, the movement and operation of each part can be remotely controlled by manual operation, and the teaching operation for the works W1, W2, and W3 can be performed, and the memory in the control means 14 (Fig. (not shown) is used to input the user program.

FIG. 2 mainly shows a circuit block diagram of the power supply device 12! It is an explanatory diagram. Reference numerals 16 and 17 denote an electrode supply roll 11 provided in the power supply device 12 and a pair of power supply rollers, and the electrode 13 is pulled out from the supply roll 16 by the simultaneous rotation of the supply roller 17, and -uJ1 sales f-
It passes through the tube 18 to the torch 11, and the torch 1
The tip protruding from 1 becomes the welding point.

19 and 20 are voltage applying means and energization state detecting means similar to the electric current gA device 12, of which the voltage applying means 19 is connected to r<7 electric power source 19a, -゛ sensor power source 19b,
A foam j19c for abnormal approach detection, a changeover switch 19d that connects one end to the electrode 13 and selectively connects it to either the welding power source 19a or the welding power source 19b, and the torch 11, one end of which is connected to the electrode 13. A mantle 11a consisting of (however, a mantle 11a consisting of
A is connected to the electrode 13 (insulated by 1L) and consists of a normally open on/off switch 196, etc., which is connected to the IJ electric gap 19C for the first approach detection.

Further, the energization state detection means 20 has one end connected to the sensor power supply 191) and the 46 normal approach detection tortoise 19e, and the other end connected to the opposite switch 19d side of the welding power 113X19a and each pallet 4. 5 and 6, energization state detection circuits 2Lla and 20b for the sensors and for detecting the proximity of different "K" are connected to the valley machining stations 1a, 2a, and 3a which are distributed four times to the workpieces W1, W2, and W3.
.

and each energization state detection circuit it&20a, 20b
The change in the energization state (change in current, voltage, or both) at (φ output b4) is manually controlled by the control means 1
4, and energization state detection means paths 20C and 20d for detecting abnormal approach.

During sensing, when the electrode 13 protruding from the torch 11 is used as a sensor to explore the welding line of the valley workpieces W1, W2, and W3, during teaching, the posture, movement speed, welding conditions, etc. of the torch 11 are carried out according to the program obtained by teaching. During tests to confirm the operation of the welding robot 7, when manually moving the torch 11, and during any operation of the welding robot 7, such as when waiting for automatic welding, the open/close switch 19e is always closed and the mantle 11 is closed.
Apply the Iiyama voltage (this is a high-voltage low current at the same level as the sensor voltage) to a, and connect the abnormal approach detection power supply 1.
9C2 open/close switch 19e2 energization state detection circuit 20b9
The abnormality detection means constituted by the energization state detection output circuit 20d and the jacket 11a is kept in an operable state at all times.

21, 22, and 23 are return buttons for lines 2 and 3, respectively, attached to the control means 14, and
The abnormality registration stored in the control means 14 is deleted by pressing the button after the abnormality has been treated and returned to normal.

Next, the welding robot 7 moves to the processing stations 1a, 2a,
The automatic welding of the works W1, W2, and W3 arranged at 3a will be described with reference to the flowcharts of FIGS. 3 and 4.

Note that Po indicates a reference point.

Currently, processing stations 1a, 2a, and 3 are in the initial state.
Pallets 4, 5, and 6 each carrying workpieces W1, W2-W3 are arranged on a, and a locking device 1
The workpiece W2 is positioned and fixed at a predetermined position by t8, 9, and t10.
Assume that there is.

(1) First, it is determined whether or not the program includes welding fi command information.

(2) If included, specify 1→2→3 as nL41'F to be processed.

(3) Next, the operation of switching the changeover switch 19cl'1-1d to the connection source iqa is omitted.

■Determine whether the torch 1 is located at the reference point PO.

(5) If the position is not 11t, command an operation to position 11 torches at the cutting point PO.

(6) Determine whether line 1 is an abnormal registration. Initial letter +1! !
Therefore, there is no abnormal registration, and the judgment is 1NO.

(7) Pallet 4 is placed at processing station 1a! f
Determine whether it is fi.

With the pallet contact Hagi signal from the locking device 8, “Y”
It is judged as ES.

(Wl・-chi 11 is connected to the bath W1 at the starting point υU l″1
Command the positioning operation f'l' to 8.

(9) Next, command execution of welding work. As a result, the torch 11 moves from the point P1s to the 'tt1 contact end point P.
Automatic welding is performed along the bath tangent up to le.

(10) During execution of the welding work, check whether an abnormality is detected for each unit movement amount (step amount) of the torch 11. 6) If there is no “energization” signal from the energization state detection circuit 20d, “N”
The judgment is "O".

(11) Next, it is determined whether the torch 11 has reached the welding end point Ple. [If YES J, command to stop welding work. As a result, the changeover switch 19d is switched to the sensor power source 19b, and the feed roller 17
When the rotation of the electric motor 13 stops, the feeding of the electric motor 13 stops.

(12) Then, command is given to return the torch 11 from the welding end point Pie to the reference point PQ.

(13) Command to release pallet 4. This releases the locking device 8 and releases the positioning and fixing of the pallet 4.

(14) Next, command one-pitch driving of line 1. As a result, the roller conveyor of line 1 is driven by one pitch, and the processing station 1a has (marginally unwelded roller W)
One pallet 4 is arranged 11, and the pallet 4 is positioned and fixed by the operation of the locking device fFffi 8 in sequence.

(15) Check 1υ1 whether to move to the next line, and select [YES].
If it is J, the process returns to steps (2) and (3).

Then, steps G) and subsequent steps are executed for the workpiece W2 on line 2, but during the welding work in step (9), the torch 11 moves from the r1 welding start point P2s to the welding end point P2s.
2e, the mantle 11a has an abnormal protrusion t between the workpiece and v2.
When approaching the mantle 11a and the abnormal protrusion t, electricity is applied and discharged, a change in voltage and/or current is detected by the energization state detection circuit 20b, and a signal of 1- energization is output from the energization state detection output circuit 20d. is issued to the control means 11.

Therefore, in step (1o), it is determined to be 1-YESJ, and a command is given to interrupt the welding work, and the torch 11 is stopped at the abnormality point P2i, and the changeover switch 19d is switched to sensor 7i[', 19b, and further the feed roller 1
When the rotation of the electric motor 13 stops, the feed 0 of the electric motor 13 also stops. At the same time, it outputs a command to operate a W warning device (not shown; for example, a buzzer or a flashing lamp) attached to the control means 14. Then, record a signal indicating that line 2 is abnormal.

Next, from the abnormality occurrence point P2i of the torch 11 to the reference point P
Command backtracking to o. As a result, as shown in FIG. 3, the torch 1 safely returns to the reference point PO by retracing the route it has traveled so far (ie, P2i→P28→Po).

This backtracking step is the step (1) described above.
Continuing between 4) and (15).

Subsequently, the process returns to steps (2 and 3) and executes steps (31 and below) for the workpiece W3 on line 3.

If there is no abnormality in line 3, return to line 1 and repeat steps (3) to (1) for workpiece W1.
Execute 5).

Then, even when it is line 2's turn again, if the above-mentioned abnormality of line 2 is still not taken care of and the return button 22 is not operated, the control means 14 will be activated.
When the judgment is ``YES'' and the process proceeds between steps (14) and (15), the torch 11 will jump over line 2, where the abnormality is being registered, and move to line 3 for a second. From then on, unless the return button 22 is operated, the torch 11 will move to the work Wl-W3 of the line 3;! i' Perform automatic welding alternately.

Before long, the worker noticed the activation of the alarm and put a special mark on the workpiece W2 with the abnormal protrusion t.
Separately, at P4, the locking device 9 is released by manual operation, the roller conveyor of line 2 is driven one pitch, and the pallet 5 carrying roller W2 is automatically restored to the force 11 station 2a. ) and the locking device 9 are operated to position and fix the pallet 5. In this way, the worker takes action on line 2 and then presses temporary return 22.
If the operation is performed, the MiJ abnormality registration will be deleted, so the welding Rojo Soto 7 will perform automatic x8 welding in the normal order of lines 1 → 2 → 3 from the next time.

In addition, the roller conveyors of lines 2 and 3 and the lock device 8
・Even when it is determined that the step ω is 140 due to a failure such as 9 or 10, the alarm will move by 1V and the abnormality of the line will be sounded, and the line will be skipped and moved to the next line. .

In the above-described embodiment, the abnormality detecting means provided in the welding robot 7 detects an abnormal protrusion e on the workpiece as an "abnormality" when the torch mantle approaches it. The present invention can also be implemented in the same manner using other means for detecting abnormalities, such as means for detecting defects in the workpiece or means for detecting abnormalities in the workpiece using a television camera 5.

As detailed above, the 1LiU lip method of the present invention (
If it gets distorted, the workpiece C that can be placed in the processing station and (
(Before starting automatic welding,
Is the /ba registered, that is, its line strength (Ji+nJi
If there is an abnormality and the deafness remains untreated, the system skips over that line and moves to the next line, so the work that flows through multiple lines is repeated in order. Even if an abnormality occurs on one line during processing, the operation of other lines will not be stopped, and the decline in production efficiency can be kept to a minimum; this is especially true for production lines in unmanned factories. t: A great effect is achieved.

[Brief explanation of drawings]

FIG. 1 shows a plane 1f of a processing line showing a welding robot as an example of implementing the 91M method of the present invention! 'E+n
Figure i5 and Figure 2 are circuit block diagrams of the ``city tram'' system of the robot, Figure 3 is a functional diagram, and Figure 4 is a flowchart. In the figure, l, 2, and 3 are addition, L line, 4, 5, and 6 are pallets, 7 is r [l contact bot, 11 is convex NK l, -chi, 12 is 'tun FA device, 14 is side Part means゛、Wl・W
2 ・W3 is the work and PO is the semi-final point. Applicant: ShinMaywa Kosaku Co., Ltd.

Claims (1)

[Claims] ■Providing an industrial robot that is shared by multiple processing lines,
A processing tool provided in the robot moves sequentially through the processing lines based on commands from a control means as appropriate, and automatically processes workpieces that are intermittently transferred in each processing line, wherein the processing tool is We set a reference point to return to every time the machining work on each machining line is completed,
The control means registers an abnormality in the machining line when there is an abnormality related to the machining line and/or the workpiece, and registers the machining line to which the machining work is to be started each time the machining tool returns to the reference point. An industrial robot characterized by determining whether or not an abnormality is registered as 41 or not, and instructing the robot to skip over that processing line and move to the next processing line if there is an abnormality 11 record. control method. (2) The scope of the present invention is such that, when there is an abnormality M during the machining operation, the machining tool interrupts the machining operation and then returns to the reference point by retracing its path. 2. A control method for an industrial robot according to item 1. G) The control method for an industrial robot according to claim 1, wherein the control means is provided with a return button at each processing line, and the abnormality registration is deleted by an operation signal of the return button. .