JPH0563806B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for controlling a robot placed in front of a press brake when the robot supplies a workpiece.

When a workpiece is automatically supplied to a processing machine such as a press brake by a workpiece supply device such as a robot, gauges such as a back gauge and a front gauge have conventionally been used for positioning the workpiece. However, when these gauges are used, there are certain problems, such as the need to install a sensor for each gauge and monitor the feedback from these sensors in order to check, for example, whether the workpiece is reliably hitting the gauge or not. The work is difficult, and it is also difficult to guide the robot to an accurate position based on the feedback.

Moreover, with the development of robots and the like, operations must be performed continuously in a short period of time, and conventional control methods have not been able to keep up with such continuous supply operations.

The present invention has been made in view of the conventional problems as described above.

Embodiments of the present invention will be described below with reference to the drawings.

First, its configuration will be explained.

1 and 2 are a side view and a perspective view of a press brake and a robot to which an embodiment of the present invention is applied.

Imaging devices 1 and 1', such as CCD cameras, are placed at appropriate positions on the front or rear of the ram 5 that is installed on the upper part of the press brake 3 and holds the punch 4, and at its ends for monitoring as described below. Arrange it so that it can be carried out properly. That is, the imaging device 1 mainly monitors the angle of the workpiece W with respect to the mold 7 in a horizontal plane, and the imaging device 1' monitors the bending position and angle of the workpiece W. Information from these imaging devices 1, 1' is fed back to the robot 9 and press brake 3 and used to control their operations, as will be described later. Note that imaging light sources 10 and 10' are provided opposite to the imaging devices 1 and 1'.

FIG. 3 is a block diagram of the work supply position detection device according to this embodiment.

The imaging signal output from the imaging device 1 or 1' is
The amount of information can be compressed by controlling the sampling timing with the sample timing controller 11, and the signal is converted into a digital signal by the A/D converter 12. This digital signal has a signal level threshold determined by the variable resistor 13, and becomes a binary signal indicating white or black information.
By switching the switch 15, the binary signal that captures the state before the workpiece W is supplied to the press brake 3 is transferred to the A memory 17, and the binary signal that captures the state after the workpiece W is supplied to the press brake 3 is transferred to the A memory 17. The converted signals are selected to be sent to the B memory 19.

Therefore, the information in the A memory 17 is in a state where there is no workpiece W, that is, for example, information that sets only the punch 4 and the mold 7 to the black level, and the information in the B memory 19 is in a state in which there is a workpiece W, that is, for example, in a state where only the punch 4 and the die 7 are at the black level. 4. The information sets both the mold 7 and the mold 7 to the black level, and the following holds true: |A memory information−B memory information|=Information only for the workpiece W. However, the field of view of the imaging devices 1 and 1' is set so as not to capture the robot hand 9'.

Therefore, the binary signals of the A memory 17 and the B memory 19 are each sent one byte at a time to the arithmetic unit 21, and the difference between the two signals is taken, and information on only the workpiece W is extracted and stored in the C memory 23. That is, the C memory 23 contains information that sets only the workpiece W to the black level.

Next, the binary signal of the C memory 23 is sent to the CPU 25.
At the same time, it is sent to a serial converter 27, and the binary signal sent in a byte array is converted into a serial array. Regarding this serially arranged binary signal, the black level signal remains unchanged, the white level signal is changed to black level by the inverter 29, and is sent to the counter 31 to count the number of pixels. This count signal is sent to the CPU 25 and is used as information indicating the address of the pixel within the image.

After the above-mentioned Hadoka air processing, the CPU 25 performs software processing as described later.
Software processing is advantageous in that it can give flexibility to the processing and can respond to changes in processing conditions such as the shape of the work W, bending position, angle, etc.

Furthermore, from the A and B memories 17 and 19 mentioned above,
Transfer of information to the CPU 25 and serial converter 27 is performed in parallel in consideration of shortening transfer time, and each memory 17, 19, 23 and serial converter 27 is
The timing is controlled by the clock from 3. The time from the time of imaging to the transfer of information to the CPU 25 is within 0.3 seconds at maximum.

Also, the information from the serial converter 27 is converted into a D/A
It is also possible to send the image to the video monitor 37 via the converter 35 and reproduce the image of only the workpiece W.

Next, the operation of this embodiment will be explained according to the software processing procedure in the CPU 25.

First, the control for feeding the workpiece W into the mold 7 at right angles will be explained.

First, as a preparatory step, the process shown in FIG. 4A is performed to obtain data that will serve as a standard for perpendicularity determination.
That is, first, as shown in Figure 5, use a straightedge.
W' is grasped by the hand 9' of the robot 9 and supplied to the mold 7 at right angles, and is imaged by the imaging device 1 to perform the above-mentioned hardware processing. As a result, the binarized signal entering the C memory 23 becomes black in the area of the straightedge W' and white in other areas, as shown in FIG. This is taken as a reference image and taken into the CPU 25 (step 100).
Next, for example, Y address = 0, 50, 100, 1
50,200 is set as the reference Y address, and each reference Y
The X address is sequentially scanned from 0 at the address (step 110), and the point where the captured binary signal changes from white to black, that is, the X address of the edge of straightedge W', i ₀ , i ₁ , i ₂ , i ₃ , _i4 is memorized (step 120).
These stored X addresses serve as a reference for determining the perpendicularity of the workpiece W to the mold 7 in later processing.

After the above preparations, the process moves to the normal workpiece supply operation and the process shown in FIG. 4B starts.

First, the supplied workpiece W is imaged by the imaging device 1, and the information stored in the C memory 23 through the aforementioned hardware processing is taken into the CPU 25 (step
130).

Next, at each reference Y address, the Y address is sequentially scanned from 0, and the binarized signal at each point is examined (step 140). At this time, if the full binary signal is white at all reference Y addresses = 0, 50, 100, 150, 200, this indicates that the workpiece W has not been supplied yet, so step
The process returns to step 130 to perform imaging again and input new imaging information from the C memory 23 (step 150).

If the workpiece W is supplied, there will be a point at which the binary signal changes from white to black at any of the reference Y addresses, so select the two points with the maximum distance between them and The two X addresses are memorized (step 160).

For example, if X addresses = q ₀ , q ₂ are stored for reference Y addresses = 0, 100, respectively, then the X addresses q ₀ , q ₂ and the reference stored in advance at the preparation stage Calculate the difference between the edge of the straightedge W' and the X address i ₀ , i ₂ for the Y address = 0,100, and rotate the robot 9 in the horizontal plane so that q ₀ −i ₀ =q ₂ −i ₂ . (steps 170-190).

When the workpiece W is fed into the mold 7 at right angles in this manner, control of the bending position and angle of the workpiece W is started.

First, the workpiece W is imaged by the imaging device 1', and the information stored in the C memory after the above-mentioned hard processing is captured.
Import into CPU25. Next, based on this captured information, as shown in FIG. 7, the address of the end surface of the workpiece W inserted into the press brake 3 is detected, and the punch 4 in which the address has been stored in advance is detected. The distance L to the tip of is detected. The robot hand 9' is moved back and forth so that the detected distance L becomes equal to a predetermined dimension, thereby controlling the bending position.

Next, the press brake 3 is driven to start bending. During processing, the workpiece W is imaged by the imaging device 1',
Through the hardware processing described above, image information as shown in FIG. 8 is obtained in the C memory 23. This is CPU25
and starts scanning in the X-axis direction from the origin of the X, Y address. Detects the first case where the binary signal changes from white to black, black to white, white to black, or black to white on the same scanning line, and detects the first point where black changes to white.
The addresses of A ₀ and the second point B ₀ that changed from white to black are stored. As the scanning line moves downward, the first point on the same scanning line that changes from black to white
An and the point Bn, which changes from white to black second, approach, and both points converge on point C. The address of this focal point C is stored, and the bending angle α is calculated based on the stored addresses of points A ₀ , B ₀ , and C. When the bending angle α thus obtained reaches a predetermined value, the bending process is terminated.

It should be noted that the above-described content is merely an explanation of one embodiment of the present invention, and it goes without saying that the present invention is not limited to the above-mentioned content.

As can be understood from the above description of the embodiments, the present invention is, in short, an apparatus for controlling the robot 9 disposed in front of the press brake 3 to supply a workpiece W to the press brake 3. an imaging device 1 for imaging a state in which a ruler W' held by a robot hand 9' of the robot 9 is supplied perpendicularly and horizontally to the mold 7 of the press brake 3; Therefore, the X addresses i ₀ , i ₁ , i ₂ of the imaged edges of the ruler W′ are set as the preset reference Y addresses 0,
50 and 100, and a first storage section that stores images corresponding to numbers 50 and 100, and images captured by the imaging device 1 when the robot hand 9' grips the workpiece W and supplies the workpiece W to the press brake 3. a second storage unit that stores the X addresses q ₀ and q ₂ of the workpiece W in correspondence with the reference Y addresses 0 and 100;
A control unit that controls the robot 9 so that the difference between the corresponding X addresses stored in the first storage unit and the second storage unit becomes (q ₀ −i ₀ =q ₂ −i ₂ ). That's what happens.

As is clear from the above configuration, in the present invention, the imaging device 1 captures an image of the ruler W' held in the hand 9' of the robot 9 positioned at right angles to the mold 7 of the press brake 3. Using this imaging data as a reference, the robot 9 is controlled by comparing the imaging data of the workpiece W with the above reference data when supplying the workpiece W, so that the workpiece is always placed at right angles to the mold 7 of the press brake 3. W can be supplied and accurate processing can be performed.

[Brief explanation of the drawing]

1 and 2 are a side view and a perspective view of a press brake and a robot, FIG. 3 is a block configuration diagram of an embodiment of the present invention, FIG. 4 is a processing flowchart of FIG. 3, and FIG. 5 6 is a plan view showing the relationship between the straightedge and the mold, FIGS. 6 and 8 are views showing captured images of the workpiece, and FIG. 7 is a view showing the bending position. 1, 1'...Imaging device, W...Work, 3...Press brake, 9...Robot, 13...Variable resistor, 1
7, 19, 23...Memory, 25...CPU.

Claims (1)

[Claims] 1 A device for controlling the robot 9 disposed in front of the press brake 3 to supply the workpiece W to the press brake 3, and controlling the ruler W' held by the robot hand 9' of the robot 9. An imaging device 1 that images the state in which the press brake 3 is fed perpendicularly and horizontally to the mold 7, and an X address i ₀ , i of the edge of the ruler W′ captured by the imaging device 1. ₁ , _i2 corresponding to preset reference Y addresses 0, 50, 100; When supplying the imaging device 1
X address of the workpiece W imaged by
The difference between the second storage unit storing q ₀ and q ₂ corresponding to the reference Y addresses 0 and 100, and the corresponding X addresses stored in the first storage unit and the second storage unit is ( q ₀ −i ₀ =q ₂ −i ₂ ). A control device for a work supply robot for a press brake, characterized in that the control device comprises a control section that controls the robot 9 so that q 0 −i 0 =q 2 −i 2 .