JPS60118907A - Industrial robot - Google Patents

Abstract

PURPOSE:To ensure correction of position at playback by applying automatic correction a teaching position by a teaching personnel to a position to be displayed to a position where a work is to be taught. CONSTITUTION:A keyboard 26 is operated by a teaching personnel and positions X1, Y1, Z1 and R1 of a center 12 are inputted to a control circuit 27 as the 1st teaching position. The control circuit 27 applied D/A conversions 31-34 to the position signals X1, Y1, Z1 and R1. Comparators 22-25 compare signals from the converters 31-34 with signals detectors 18-21, and the difference is fed respectively to drivers 3-5 and 17. The drive sets the center 12 to the X1, Y1 and Z1 and sets a case 2 to the turning position of the R1. Then a picture processing circuit 11 receives a slit image from a camera 7 so as to detect a deviation of the center 12 from a reference position by means of the light cut method. Deviation signals DELTAX, DELTAY and DELTAZ outputted from the picture processing circuit 11 are added to a teaching position signal from the control circuit 27 thereby setting the center 12 to the correcting position and also storing the result of addition to a storage circuit 35 as a teaching position signal.

Description

[Detailed description of the invention] The present invention relates to industrial robots.

In so-called teaching-playback type robots, in which the work position for the workpiece is taught in advance and the actual work is performed at the taught work position, the teacher's teaching position may deviate from the position that should be taught. Therefore, if playback is performed with such a taught position, normal work may not be possible due to the setting error of the workpiece, and playback With this robot equipped with a correction device that sometimes performs position correction, there is a risk that the correction device may exceed the zero correction range.

The present invention has been made in view of the above points, and its purpose is to provide an industrial robot that can reliably teach the original working position to a workpiece and can perform a preferable playbank. .

According to the present invention, the objects are a movable part, a means for specifying the position 1a of the movable part, a means for installing all the movable parts at the position specified by the position specifying means, and a setting means. means for detecting the deviation of the movable part from the reference position relative to the workpiece set by the detecting means; and means for correcting the position specified by the position specifying means based on the deviation detected by the detecting means; This is achieved by an industrial robot comprising means for storing the corrected position obtained by the correcting means as a taught position.

Next, the present invention will be explained in more detail with reference to a preferred embodiment shown in the drawings.

In the figure, a case 2 as a movable part is attached to the tip l of a three-axis + M-intersecting robot body so as to be rotatable in the human direction around [111R, which is parallel to the two axes. The tip portion 1 is independently moved in the X-axis direction, Y-axis direction, and Z-axis direction by the operation of the X-axis direction drive device 3, the Y-axis direction drive device 4, and the two-axis direction N1 movement device 5. That is, the tip l can be placed anywhere in the X-Y-2 space by the driving device 3.
9 is moved to the operation of 4 and 5. The drive devices 3.4 and 5 each consist of a drive electric circuit, a servo DC motor, etc. A slit light source 6 and a television camera 27 are attached to the case 2, and the light source 6 emits slit light that intersects the X-Y plane to form a slit light image 10 on the work surface 9 of the workpiece 8. do. The camera 27 captures a slit optical image lO from a direction inclined with respect to the axis, and supplies the captured slit image to the image processing circuit 11. II! The II image processing circuit 11 uses a so-called optical cutting method to determine the projection position 13 of the center position 12 of the optical case 2 onto the X-Y plane on the work surface 9.
The reference position above, the position to be taught on the work surface 9, in this example, the projection position 14a of the center position 14 in the width direction of the work surface on the X-Y plane in the X-axis direction and Y Reference distance 16 between the deviations ΔX and ΔY in the axial direction, the projection position 15 of the center position 12 on the two axes, and the projection position 15a of the father point 13a of the R axis and the slit optical image lO on the two axes. 16
The side groups ΔZ in two axial directions from a are detected.

The case 2 is rotated in the A direction about the R axis relative to the distal end portion 1 by the operation of the R axis drive device 17. Drive device 1
Similarly to the drive units 3 to 5, the drive unit 7 includes an air circuit, a DC servo motor, and the like. The position detectors 18, 19 and 20 detect the positions of the tip 1 in the X-axis, Y-axis, and X-axis directions, respectively, and are composed of, for example, potentiometers. Detector 21
detects the rotational position of the case 2 in the A direction with respect to the tip part work; this also consists of a potentiometer, for example. Each detection signal of the detectors 18 to 21 has an X axis ratio of 22 and a Y axis ratio of 22.
The axial ratio return 23. is supplied to the two-axis comparator 24 and the R-axis ratio return 25. Keyboard 26 operated by the instructor
Under the control of the control circuit 27, the taught position signals from the X-axis adder 28, the Y-axis adder 29, and the two-axis adder J4. 30 and an R-axis digital-to-analog converter 31. Therefore, the adder 28 receives a taught position signal indicating the moving position in the X-axis direction, and the adder 29 receives a taught position signal indicating the moving position in the Y-axis direction. The converter 30 receives a teaching position signal indicating the movement position in the Z-axis direction, and the converter 31 receives a teaching position signal indicating the movement position in the Z-axis direction.
If a correction signal based on rotation deviations ΔX, ΔY, and Δ2 related to direction A around the axis is not output,
The instruction Q[(N) from the control circuit 27 is supplied as is to each digital-to-analog converter 32, 33 and 34,
When the correction No. 4i1 is output, the control circuit 27
This correction signal is added to the duck taught position signal and the corrected taught position signal is supplied to converters 32, 33 and 34. The converters 32, 33, 34 and 31 convert the received digital position signals into analog position signals and use t'L as a target position signal to the comparators 22, 23.

24 and 25, respectively. The comparators 22 to 25 compare the received target position signal with the detection signal as the current position signal from the detectors 18 to 21, and supply the difference to the drive devices a to 5 and 17. 3-5 and 17
is moved in the direction of the tip 1'f, X@, Y axis, and z axis until the difference signals from the comparators 22 to 25 become substantially zero, and the case 2 is rotated in the A direction around the R axis. . When teaching each position using the keyboard 26, the control circuit 27 detects that the signals due to the deviations jX, ΔY, and Δ2 from the image processing circuit 11 become substantially zero, and adds S unit 28 to this detection. The corrected position signal output from 29.30 and the position signal supplied to the converter 31 are stored in the storage circuit 35 as a taught position signal.

In the industrial robot 40 configured as described above, the keyboard 26 is operated by the teacher, and the digits d The control circuit 27 outputs the position signal XI*Yl 1 Zl and the R+t'' adder 28゜2.
9.30 and converter 31, respectively. position signal
I*Yl*ZH(D reception adder 28, 29
゜30 is supplied as it is to converters 32, 33.34, and converters 32, 33.34 and 3 convert the supplied position signals Xs + Yl + zI and R1 as digital signals into analog signals. It is supplied to each of the comparators ρ~25. Comparators 22-25 are converters 32.33.34
and 31 with the signals from the detectors 18-21 and feed the difference to the drives 3.4.5 and 17, respectively, so that the center 12 is aligned with the X, Y and Z axes. The case 2 is moved in the axial direction, the case 2 is rotated in the entry direction, and the center 12 is
, yt and zl, and case 2 is set to the rotational position of R1. After this setting, the image processing circuit 11 receives the slit image from the camera 7 and uses it to
20 The deviation from the reference position is detected by the optical cutting method. The image processing circuit 11 generates a slit image 4 obtained by the camera 7.
Distance (deviation) of the perpendicular from the center 43 of the screen 42 to 1
4 and the distance (deviation) 47 between the intersection 45 of the perpendicular line with the slit image 41 and the center 46 of the slit image 41, and the rotation in the input direction about the R axis from the control circuit 27 and the distances 144 and 47. Deviations of the center 12 in the X-Y-Z space ΔXhΔY1 and Δ
Detect z1. The adder 28 receives the deviation signals ΔXi, ΔYl, Δz1 after the image processing in the image processing circuit 11 is completed.
is output, this deviation signal and the position signal from the control circuit 27 are added, and the position signals (,X+ΔXI), (Yl+ΔY+) and (Zs
+ΔZl). As a result, the center 12 is moved again to the positions (XI+ΔXt), (Yl+ΔY+)
and (Zl+ΔZt). Center 12 is located (
X! +ΔXI), (Yl+ΔYl) and (Zt+ΔZl
)K is set, the image processing circuit 11 outputs signals with substantially zero deviation regarding the X, Y, and Z axes, and the control circuit 27 detects this and outputs signals with substantially zero deviation from the adders 28 and 29.
．． 30 and converter 31 or the position signal input/output
Xx+ΔXI), (L+ΔY1).

(Z+10ΔZt) and R1 are stored in the storage device 35 as a first taught position signal. Thereafter, the keyboard 26 is operated, and the second. The above operation is repeated every time the third position is taught. Accordingly, the center 12 of the workpiece 8 with respect to the work surface 9 and the case ? Teaching regarding the position of the tip 1 with respect to the tip l is performed.

During playback, the taught position signal stored in the storage circuit 35 is read out and sent to the adders 28, 29, and 30, respectively.
and supplied to the converter 31, the center 12 is moved and the case 2 is rotated in the same way as in teaching. Accordingly, the work tool im9, which is attached to the case 2 during playback, is supplied with sludge by a working tool, for example, a coating nozzle. If the teaching is done for the position 14, 46° 47.48.49, then the sound 9 will be at the position 1i14, 16, 47.48.49.
are supplied sequentially along the When setting a new workpiece 8 to a working position, if this new workpiece 8 is set at a position that is slightly different from the set position at the time of teaching, the industrial robot 40 will be set at a position similar to that at the time of teaching. , the image processing circuit 11
The center 12 is moved by 1° with correction based on the deviation signal from the center so that optimal work can always be performed even during play pack.

In the above specific example, the deviations (i-number ΔX, ΔY, and Δ2) output from the image processing circuit 11 are added to the taught position signal from the control circuit 27 to set the center 12t-corrected position, and the addition Although the result was stored in the storage circuit 32 as a taught position signal, the present invention is not limited to this.
For example, the image processing circuit 11 outputs a signal indicating whether there is a substantial difference between the position taught by the keyboard 26 and the position to be taught, and whether the difference is positive or negative. 11, the taught position signal from the control circuit 27 is subject to minute shifts based on the sign or negative of the difference. A correction signal indicating the amount of vl is sent to the adder 28.
.about.30, thereby moving the center 12 to the correction position, and the correction position signal outputted from the adders 28 to 30 at the time when the image processing circuit 11 no longer outputs a signal indicating a difference is expressed as X. It is also possible to cause the writing circuit 3F to read the teaching position signals regarding the axes, the Y-axis, and the z-axis. This operation can also be applied in playback as well. In addition, the industrial robot of the present invention is not limited to an orthogonal three-axis type robot, but may also be applied to other robots, and therefore the present invention is not limited to the above-mentioned specific examples.

As described above, according to the present invention, the teaching position by the teacher can be automatically corrected to the position of the workpiece to be taught, so that the teaching is performed in the following manner: 1. In addition, it is possible to reliably perform position correction during playback, and it is possible to eliminate teaching beyond the correctable range.

Furthermore, since the position corrected during teaching is memorized, corrections during playpacking are reduced and the operating time during playpacking is shortened.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a preferred embodiment according to the present invention, and FIG.
1 is an electric circuit diagram of the specific example shown in FIG. 1, and FIG. 3 is an explanatory diagram of the operation of the specific example shown in FIG. 2... Case, 11... Image processing circuit, 28.
29°30... Adder, 32... Memory circuit.

Claims (1)

[Claims] (1) A movable part, means for specifying the position of the movable part,
11. Means for setting all the movable parts to the positions specified by the position specifying means, and C setting means for the setting means. Rika I
means for detecting the deviation of the jth portion from the reference position with respect to the workpiece; means for correcting the position specified by the position specifying means based on the deviation detected by the detecting means; and the correcting means. An industrial robot comprising means for storing the corrected position obtained by the method as a taught position. (2) The industrial robot according to claim 1, wherein the detection means includes a television camera 2 integrally provided in the movable part and a light source. (3) The industrial robot according to claim 1 or 2, wherein the detection means is configured to detect the deviation by a light cutting method. (4) The correction means has an adder, and the adder is configured to add the amount of deviation detected by the detection means and the friend position designated by the position designation means. The industrial robot according to any one of items 1 to 3. (6) The correction means has an adder, and this adder calculates a minute position-related quantity at the position designated by the position designation means based on the presence or absence of deviation detected by the detection means and its sign. The industrial robot according to any one of claims 1 to 3, which is configured to perform addition.