JPH05108131A - Teaching device of robot - Google Patents

Abstract

PURPOSE:To obtain the teaching device of a robot which can easily perform the teaching work in a short seriod of time. CONSTITUTION:A robot main body 1 performs the liquid agent applying work by tracing a liquid agent applying tool 5 at the tip part of a Z axis transfer device 4 along a work line 7 to a fixed arranged work 6. At the time of performing the applying work, the work 6 to perform the marking onto the work line 7 is photographed by a CCD camera 9, and the image data are sent to an image processing device 10. The image processing device 10 obtains the coordinates column data corresponding to the work line 7 and sends the data to a computer 11. The computer 11 converts the work line data to the internal coordinates of a robot sets a path where the liquid agent applying tool 5 should trace, further, prepares the action program of the robot, and sends it to a controller 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot for performing work such as application of liquid agent, cutting, trimming and deburring on a fixedly arranged work by tracing a tool along a predetermined path. , A robot teaching device for teaching the path.

[0002]

2. Description of the Related Art In a robot for applying a liquid agent along a predetermined line (working line) on the surface of a work such as a plate material, for example, a robot control device is equipped with a tool ( The application gun is repeatedly moved while discharging the liquid agent along a predetermined path along the work line. In such a robot, teaching by a teaching playback method is generally performed when starting work by the robot.

In this teaching, the operator sets a plurality of target points on the work line of the work,
This is performed by actually moving the tool on the target points by manual operation and storing the coordinates of the respective target points in the control device of the robot. Then, the operation program of the robot is set so that a predetermined path along the work line is obtained by interpolating the stored target points with a straight line, a circular arc, a spline curve, or the like.

[0004]

However, in the conventional teaching method described above, the teaching work is troublesome and time-consuming because it is necessary to teach a large number of target points when the shape of the work line becomes complicated. It will take a lot of time. In particular, in the case where there are many kinds of works or the kind of goods has to be switched in a short period of time, the teaching by the conventional teaching playback system is no longer sufficient. Therefore, an object of the present invention is to provide a teaching device for a robot capable of easily performing teaching work in a short time.

[0005]

A robot teaching device according to the present invention provides a robot for performing work on a fixedly arranged work by tracing a tool along a work line of the work. An image pickup means for teaching a route, which picks up an image of a work with marking corresponding to the work line, and a work line detection means for detecting the work line from the image data obtained by the image pickup means. , A route setting means for setting the route of the tool based on the work line data detected by the work line detecting means.

[0006]

According to the above means, the work line is marked on the work line, and the work line is photographed by the image pick-up unit, whereby the work line detection unit automatically detects the work line from the image data. Then, the route setting means automatically sets the route of the tool from the work line data obtained by the work line detecting means.

Therefore, it is not necessary for the operator to manually move the tool to a plurality of target points on the work line of the work, and as a result, the teaching work can be completed easily.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. Here, the case where the liquid agent is applied to the surface of the flat plate-shaped work is taken as an example.

FIG. 1 shows the overall configuration of a robot including a control system. Here, the robot body 1 is a well-known 3-axis orthogonal coordinate robot, and an X-axis transfer device is provided on a machining table (not shown). 2 and Y-axis transfer device 3 and Z-axis transfer device 4 are provided. The X-axis transfer device 2
Is fixedly provided on the machining table, and the Y-axis transfer device 3 is moved to the X-axis by a drive mechanism including a motor (not shown).
It is designed to move freely in the axial direction.

The Y-axis transfer device 3 is driven by a drive mechanism (not shown) to move the Z-axis transfer device 4 provided at the front end to Y-axis.
It is designed to move freely in the axial direction. And
A liquid agent application tool 5 is attached to the tip of the Z-axis transfer device 4. As a result, the liquid agent application tool 5 is always kept in the same downward posture, and the X-axis transfer device 2 is maintained.
The Y-axis transfer device 3 freely moves it to an arbitrary position on the XY plane, and the Z-axis transfer device 4 freely moves it to an arbitrary vertical position.
The liquid agent application tool 5 has a downward nozzle portion 5a, and is configured to discharge the liquid agent at a predetermined speed from its tip.

On the other hand, the flat plate-shaped work 6 is fixedly arranged on the processing table with the surface thereof facing upward. In the present embodiment, the work 6 has a substantially parallelogram shape with rounded corners as shown in FIGS. 3 and 4, and the robot body 1 is provided on the surface of the work 6 from its peripheral portion. The liquid agent is applied in a ring shape by being located inside by a predetermined width. The annular portion to which the liquid agent is applied becomes the work line 7 of the work 6.

The robot body 1 is controlled by a control device 8 composed of a microcomputer or the like. In this case, the liquid application tool 5
Performs the liquid agent application work by tracing the path along the working line 7 while discharging the liquid agent while keeping the height position (Z-axis coordinate) constant. In performing this work, the control device 8 controls the motors and the like of the respective axes of the robot body 1 by sampling control according to the operation program stored in the memory, as described later.

When performing the liquid agent application work by the robot body 1 as described above, data regarding the route to be traced by the liquid agent applying tool 5 is required. The data regarding this route is as follows. The teaching device according to the present embodiment configured is automatically created.

That is, the Z axis transfer device 4 is provided with a CCD camera 9 as an image pickup means. The CCD camera 9 is for photographing the work 6,
In this case, as will be described later, two images of the work 6 without marking and the work 6 with marking on the work line 7 are photographed.

The image data from this CCD camera 9 is
The image is transmitted to the image processing apparatus 10. The image processing device 10 extracts the image of the marking by binarizing the two images, inverting one of them in black and white, and taking the sum with the other. Further, the image of the marking is thinned into a width of 1 pixel to obtain data of a coordinate sequence corresponding to the working line 7. Therefore, the image processing apparatus 10 functions as the work line detecting means according to the present invention.

Then, the data of the coordinate sequence is sent to the computer 11 composed of, for example, a personal computer.
This calculator 11 calculates the data of the coordinate sequence corresponding to the work line 7 by a preset calibration formula.
The path to be traced by the liquid agent application tool 5 after conversion into the internal coordinates of the robot is set. Therefore, this calculator 1
1 functions as the route setting means in the present invention.

Further, this computer 11 obtains the coordinates of each control sampling time of the robot body 1 by interpolation calculation from the above-mentioned data as the operation speed of the robot (moving speed of the liquid agent application tool 5) is set. , Create position command data. Then, the operation program is automatically added by adding the position of the liquid application tool 5 in the vertical direction (Z-axis direction), the interlock with the peripheral device, the on / off condition of the liquid application tool 5, etc. to this position command. It is designed to be created. This operation program is sent to the control device 8 and stored in the memory.

Next, the operation of the above configuration will be described with reference to FIGS. FIG. 2 shows that when the robot body 1 performs the liquid application operation on the work 6, the teaching apparatus according to the present embodiment automatically sets the path of the liquid application tool 5, and further creates and controls an operation program. Device 8
Shows the procedure to enter.

First, in step S1, the CCD camera 9
The work 6 is photographed. This photographing is performed by moving the CCD camera 9 above the work 6 while the work 6 is fixedly arranged at a predetermined working position, as shown in FIG. At this time, an image of the work 6 is photographed on the screen 9a of the CCD camera 9 as shown in FIG. 4, and the image data is binarized by the image processing device 10. Figure 3
The binarized image at this time is shown in (a), and here, the work 6 is a black level image and the background is a white level image.

In the next step S2, the operator marks the work line 7 of the work 6.
Then, in step S3, the work 6 marked by the CCD camera 9 is processed as in step S1.
Is taken. This image data is also processed by the image processing device 1.
Binarization processing is performed at 0. FIG. 3B shows the binarized image at this time, and the background and the marking portion are white level images.

As described above, when two pieces of image data are input to the image processing apparatus 10, the image processing apparatus 10 inverts one of them in black and white and takes the sum with the other in step S4. As shown in (c), the image with only the marking is extracted. Since this image has an annular shape having a width of several pixels, in step S5, the image processing apparatus 10 passes the center of the width of the marking image as shown in FIG. 3D. Extract thin lines of pixel width.

Further, in step S6, from the coordinates (x, y) of each point constituting the image in which the marking image is thinned to a width of 1 pixel, a coordinate string (x1
, Y1), (x2, y2), ... (Xn, yn) are obtained. This coordinate sequence corresponds to the work line 7 of the work 6, and in this case, the liquid agent application work is performed, for example, in such a manner as to make one turn in the clockwise direction from the upper right part of the work line 7 of the work 6. The starting point of the work is the coordinates (x1
, Y1) and the end point corresponds to the coordinate (xn, yn).

The data of this coordinate sequence is input to the computer 11, and in step S7, the computer 11 converts the data of the coordinate sequence into the internal coordinates (X, Y) of the robot by the calibration formula, and The application tool 5 obtains route data to be traced. This route data is XY
Coordinate sequence (X1, Y1), (X2, Y2), ... (Xn,
Yn).

Then, when the operation speed of the robot is set in step S8, the X and Y coordinates of the liquid agent application tool 5 with respect to the operation time are determined as shown in FIG. 5 (a). In step S9, the computer 11 determines from this relationship that
The position coordinates at each sampling time are obtained. In this case, assuming that the sampling time interval is Δt, FIG.
As shown in (b), the coordinate sequence (X1 ', Y1'), (X2 ', Y2'), ... (X
m ', Ym') is obtained by interpolating each data shown in FIG. Each of these coordinates serves as a position command for the robot.

Furthermore, the vertical direction (Z
When the position coordinates (in the axial direction), the interlock with the peripheral device, the on / off conditions of the liquid application tool 5, and the like are set, the computer 11 calculates the operation program from the data and the position command in step S10. To create. This operation program is written in the memory of the control device 8 in step S11, and then the robot body 1 is activated (step S12).

The control device 8 controls the robot main body 1 by the operation program created in this way, whereby the liquid agent application tool 5 applies the liquid agent over the work 6 fixedly arranged on the processing table. While being discharged, the work 6 is traced along a path along the work line 7, and thus the work 6
Then, the liquid agent application work is executed. This work is repeatedly executed for the work 6 of the same type, and when the type of the work 6 is changed, the operation program as described above is created again.

As described above, according to the present embodiment, the teaching work, which was conventionally performed based on the manual operation, is automatically performed. Therefore, even if the work line has a complicated shape, teaching work can be completed in a short time without troublesome work, and thus it is possible to sufficiently cope with small-lot production of a wide variety of products. is there.

In the above embodiment, the case where the work 6 has a flat plate shape (Z-axis coordinate is always constant) has been described. However, as shown in FIG. In some cases, the position command requires Z-axis coordinates in addition to the X-axis and Y-axis coordinates. In such a case, in addition to the configuration in the above-described embodiment, for example, the distance sensor 22 is added to the liquid agent applying tool 5.
Should be provided.

That is, first, an operation program for XY coordinates is created in the same manner as described in the above embodiment, and thereafter, the liquid agent application tool 5 is operated by the operation program with the Z axis coordinates fixed. At this time, the distance to the work 21 is measured by the distance sensor 22 at each sampling time of the position command, and from the data, the tip of the nozzle 5a is always applied to the liquid application tool 5 from the surface of the work 21. A Z-axis coordinate sequence is obtained for each sampling time so as to maintain a constant distance that is optimal for work, and the Z-axis coordinate is added to the above-mentioned operation program to create a final operation program.

Further, in the above-described embodiment, the case where the liquid agent applying work in which the posture of the tool is always constant has been described. The orientation of the tool 23 must always match the tangential direction of the work line 7. In such a case, command data of the rotation angle (θ axis) of the cutting tool 23 in the horizontal direction is required.

In such a case, as shown in FIG. 7, from the image data, the inclination of the line segment connecting adjacent points (θ 1,
θ 2, ... θ n) should be obtained and added to the operation program as a θ axis command.

Besides, the present invention is not limited to the embodiments described above and shown in the drawings. For example, as a tool, in addition to application of liquid agent and cutting, trimming, deburring,
It may be used for drilling, etc., and can be applied to articulated robots and cylindrical coordinate robots in addition to 3-axis Cartesian coordinate robots. It is possible.

[0033]

As is apparent from the above description, according to the teaching apparatus for a robot of the present invention, the image pickup means for photographing the work having the marking corresponding to the work line, and the image pickup means obtained by the image pickup means. Since the work line detecting means for detecting the work line from the image data and the route setting means for setting the tool route based on the work line data detected by the work line detecting means are provided, the tool route can be automatically determined. Therefore, the teaching work can be set easily, and as a result, the teaching work can be easily performed in a short time.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention and showing the overall configuration of a robot including a control system.

FIG. 2 is a diagram showing a procedure for creating an operation program.

FIG. 3 is a diagram showing a binarized image by an image processing device.

FIG. 4 is a perspective view showing a state when a work is photographed by a CCD camera.

FIG. 5 is a diagram for explaining a method of calculating a position command value.

FIG. 6 is a side view of an essential part showing another embodiment of the present invention.

FIG. 7 is a diagram for explaining a calculation method of a θ-axis command showing another embodiment different from FIG.

[Explanation of symbols]

In the drawings, 1 is a robot main body, 5 is a liquid application tool (tool), 6 and 21 are works, 7 is a work line, 8 is a control device,
9 is a CCD camera (imaging means), 10 is an image processing device (working line detecting means), 11 is a computer (path setting means),
Reference numeral 22 denotes a distance sensor.

Claims (1)

[Claims] 1. A method for teaching a robot that performs a work on a fixedly arranged work by tracing a tool along a work line of the work, the work. Imaging means for photographing a work with markings corresponding to the lines, working line detecting means for detecting the working line from the image data obtained by the imaging means, and working line data detected by the working line detecting means And a path setting means for setting the path of the tool based on the above.