JPH0375904A - Offline teaching device for robot - Google Patents

Abstract

PURPOSE:To surely recognize the presence or absence of interference on offline to avoid the interference by arranging data related to positions of arms in time series in accordance with teaching data of each robot by a computer and using the same time base to display these data on one picture. CONSTITUTION:A robot 7 operated by teaching data supplied from an offline teaching device 1 is controlled by a robot control board 8 and receives data from the offline teaching device main body 1 through a storage medium 9 like a floppy disk by a storage device 3 of the main body 1 and is controlled based on this data. When the operation range of each shaft of this robot is theta imin to theta imax, the interference range of a point A of the front end of an arm 13 due to turning of a base 11 and longitudinal movement of the arm 13 is theta11 to theta12 at the time of installing two robots a certain length apart from each other. The same time base is used to display these data on one picture, thereby recognizing the interference state. Consequently, the interference is avoided by shifting the start timing or the like.

Description

[Detailed Description of the Invention] ``Management Business'' Second Field of Application'' The present invention relates to a robot system, and in particular? The present invention relates to an offline teaching device that is suitable for use when checking for interference between nodes of J(i) offline.

"Prior Art" When a plurality of industrial robots are installed on the same line or in close proximity to each other and perform work, consideration must be given to avoid interference between the plurality of robots.

If you want to avoid robot interference, it goes without saying that you can reproduce the teaching data, actually operate each robot, and visually check the operating status, but this is time-consuming and requires a lot of effort, for example, to make each robot operate. If there is a shift in the reproduced data in the time axis direction (including a case where the shift is arbitrarily caused), it is not possible to determine whether or not there will be interference.

Furthermore, according to the prior art described in Japanese Patent Application Laid-Open No. 60-99591, the three-dimensional coordinates of the arm positions are determined from the teaching data of each robot, and the shortest distance between the arms is determined from these coordinates. By comparing the distance with a predetermined value, it is possible to check for possible interference off-line.

``Problem to be Solved by the Invention'' However, the above-mentioned conventional technology has a problem in that it takes a long time to process because the distance between the arms is determined by complicated calculations. In addition, if it is determined that there is interference, it is necessary to change the program to avoid this, for example, by shifting the playback data by 1 minute on the time axis, but in this case Additionally, more complex calculations are required to determine how much time the reproduced data should be shifted.

The present invention has been proposed in view of the above circumstances, and its purpose is to accurately determine the presence or absence of interference and to appropriately supply information necessary for changing a program to avoid interference. It is something to do.

"Means for Solving the Problems" In order to solve the above problems, the present invention provides a robot, a
- has a computer that calculates data to be supplied to a robot control device that controls and reproduces the This configuration has the function of displaying the data on the same screen with the same time axis.

``Effect j'' With the above configuration, data regarding the position of the arm with both ends hot will be displayed on the computer screen with the time axes aligned, and therefore it will be possible to determine whether ``rm'' or ``arm'' will interfere at a certain time. It is possible to provide visual information that can be used as criteria for making such decisions.

"Example" Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

First, the overall configuration of the teaching device will be explained with reference to FIG. 1. Reference numeral 1 denotes the main body of the offline teaching device, and this main body 1 includes a computer 2 consisting of a microcomputer consisting of an arithmetic unit, a keyboard, a CRT, etc. ,
It is comprised of a storage means 3 consisting of a floppy disk drive, a coordinate input device 4 consisting of a dentite, for example, a printer 5 and a plotter 6 as recording output means.

The coordinate system 4 has a function of inputting node data (shape data) indicating the shape of the workpiece from a large number of points on the drawing.

On the other hand, the robot 7, which operates according to the teaching data supplied from the offline teaching device 1, is controlled by a robot control panel 8.
The storage means 3 of the off-line teaching device main body receives data from the main body 1 via a recording medium 9 such as a floppy disk, and the robot 7 is controlled based on this data.

In addition, the robot 7 described in i'iii, as shown in FIGS. 2 and 3, has a base 11 rotatably supported on the mousse 10 about a vertical axis C, etc. A first arm 12 rotatably supported around an axis O, a second arm 13 rotatably supported around an axis S orthogonal to the first arm 12, etc. It is composed of a wrist mechanism J4 movably supported at the tip of the arm 13,
It has six axes of freedom.

The operating angles of each axis in the above robot are shown in Figures 2 and 3.
As shown in the figure, if the operating ranges are 01 to θ6 and their operating ranges are θ1m1n to θimax (i = 1 to 6), then the two Rojos and 1 of Units 1 and 2 are installed at a fixed interval. In this case, the movement of the first axis (swivel of the base 11), the movement of the second axis
Due to the movement of the axis (back and forth movement of the first arm\13),
The range in which point A at the tip of arm 13 can move is shown in FIG.

The operating range of the first axis with both ends hot can be divided into three as shown in FIG. 4, depending on the possibility of interference between the rotor and toe arms. (Incidentally, the angle is not indicated, and the angle is not indicated, and (2) indicates whether it is the first or second machine.) θ min≦O1<θ, Area A is the fourth
The area where robot No. 2, located on the left side of the figure, may interfere with the mouth throat of No. 1.

(Area where there is a possibility of interference depending on the rotation angle of the other robot) θ, ≦θ1〈θ1. - Area B is an area that does not interfere with one robot arm or the other, regardless of the rotation angle.

θ12≦01≦θ1m1lX ・・・・・・
Area C is an area where there is a risk of interference between the first robot and the second robot located further to the left of the second robot.

Further, the operating range of the second axis can be divided into two as shown in FIG. 4 depending on the possibility of interference with the robot arm.

Furthermore, θ3,. ≦θ2〈θ2□ - The area is the area where one robot arm does not interfere with the other robot arm regardless of the rotation angle.

θ3. ≦θ, ≦θ2□8 ・・・・・・Area E
is the area where one robot arm may interfere with another robot arm due to the rotation angle.

Each of the above areas is determined by various conditions such as the actual dimensions of the robot arm and the mutual spacing between the installation positions of the first and second machines (center-to-center distance of each first axis). Human power, set. Then, the computer 2 receives the teaching data of the first and second machines (for example, the coordinate input device 4
), the rotation angles of the first and second axes at each teaching point are arranged along the time axis, and CR
Display on T. The time corresponding to each teaching point is calculated by calculating the distance (rotation angle) between the teaching points and the angular velocity of the arm in the relevant section (necessarily due to mechanical conditions,
or artificially determined by work demands)
It can be calculated by dividing by .

FIG. 5 shows the display screen of the CRT.

The screen shown in the upper part of Figure 5 shows the turning angle of the first axis at each teaching point of machine No. 1, which is plotted with an ○ mark in the figure, and each teaching point of machine No. 2, which is plotted with an x mark in the figure. They are displayed on the same time axis. Then, from the scale for the first machine shown on the left side of the figure and the scale for the second machine shown on the right side of the figure, the area where θ,'1>≧θ12(Il) and θ (2><θ, It is possible to visually check each region where the value is +21.By visually checking the above screen, it is possible to determine that if θ M+ and θ, (2) are simultaneously (at the same coordinates in the time axis direction) in the above region ( (in the area shown by hatching in the figure) can be recognized as an area where there is a possibility of interference.

On the other hand, the lower screen in Fig. 5 displays the angle of the second axis at each teaching point of the No. 1 machine with a circle mark toward probe 1, and also displays the angle of the second axis at each teaching point of the No. 2 machine. This screen plots and displays θ with an x mark.
For each of 2(+), θ, and 3', it is possible to recognize a range where there is a possibility of interference exceeding θ, 1 (not shown with hatching in the figure).

Then, as mentioned above, the rotation angle of the first axis and the second axis is set to C.
By displaying on RT, the section where both the first and second axes are in the area where there is a possibility of interference, that is, t1 in the figure.
The operator can visually recognize that the interval between t2 and t2 is a true interference area (interference risk area).

Note that the display on a CRT is not limited to a mode in which the time axes are aligned and parts overlap on the same screen, as shown in the example shown, but it is also possible to display on separate screens with the time axes aligned and without overlapping each other. Of course, various modes can be adopted, such as a mode or a mode in which the information is displayed separately on a plurality of CRTs.

Next, FIGS. 6 to 8 show a second embodiment of the present invention.

In this example, the rotation angles θ and θ2 of the first and second axes are converted into an orthogonal coordinate system on a two-dimensional plane using a predetermined conversion formula. Judging the X and Y coordinates of point A, we find that for Unit 1, X3)
12c is the area where the rotation angle of the second axis interferes with the arm of the second machine. The interference caution area (hereinafter referred to as the -y'efll [yellow] area) (X, 2CI) ≥ Interference risk area where there is a possibility of interference. (hereinafter referred to as RMl [let] area) For the 2nd machine, X + 21 < (hereinafter referred to as G (21st region) f, +21≦x (2'< x, ," means the 24th region
An area where there is a possibility of interference with the arm of Unit 1 depending on the rotation angle of the 2JE. (Hereinafter referred to as Ye (21 area) ) Region) The relationship between each coordinate in the orthogonal coordinate system and the rotation angle O of the lohonoto arm is as shown in Fig. 7, and from these angles, the position of the tip of the arm 13 is expressed in the orthogonal coordinate system. , X A-= (r, ・cosθ
2+r2・cos(θ2−θ3)l・sinθYA−
(rl・cO8O2+r2・cos(θ2−03)l・
cosθZA-r+'s! nθ2+r2・5in(θ,
-θ3).

Then, the conversion based on the above formula is performed for each of the first and second machines, and the temporal changes in XA and YA are displayed on the CRT of the computer 2 as shown in FIG. Note that the time t is determined by the distances in the X-axis and Y-axis directions between each first teaching point and the l→-1st teaching point, and the components of the moving speed of the tip of the lohosoto arm in each direction. Calculated.

In Figure 8, the points plotted with ○ indicate the Y coordinate of Unit 1, the points plotted with ◎ indicate the X coordinate of Unit 1,
The scale is attached to the left side of the figure. In addition, the points plotted with an x mark in the figure indicate the Y coordinate of the second machine, and the points plotted with a △ mark indicate the X coordinate of the second machine, and their scales are attached on the right side of the figure.

From such a screen, the presence or absence of interference can be determined according to the table below, for example.

That is, the area corresponding to the circle mark in the above table becomes the interference area. Note that this interference region is shown with hunting in FIG. 8. Further, in FIG. 8, the displacement curves of the X coordinates on the screen are also displayed so as to intersect in the area where the first and second machines actually interfere.

Furthermore, a third embodiment in which the judgment based on the above XY coordinates is applied will be explained with reference to FIG. 9.

First, the coordinates of the 0 point of the second robot (X%2+,
Calculate yo(2+, Zo+21).

Next, using the conversion formula described in the second embodiment, the positions of the arm tip points with the 0 point of both Rohosoto as the origin are calculated, and the coordinates of the arm tip position of machine No. 1 are obtained.
l, Y A"', Z A"' Coordinates of the arm tip position of No. 2 machine X A (21, y Al4.7 Al+ are obtained.

Next, from each of the above coordinates, the difference between the arm tip points in the x, y, and z axis directions is determined.

△X = X A"' = (X A"' -X o(2
')△Y? : Y A(11(Y A(21-yo(
21) △Z ”' Z A”' (Z A(”-Z
o"') Furthermore, the above △X, ΔY, ΔZ at each time
is displayed on the CRT of computer 2 as shown in FIG.

From this display, it can be determined that the object is in an interference caution area (shown with hunting in FIG. 9) if the following conditions are satisfied.

△ X ≦△ x Y e (X'△
Y △ y + Y e 'ゝ1△
Z ≦△ z Y e O! 'In addition,
”2 △X, △y, △2. are Rojo, /1, respectively.
This is a constant determined in advance based on conditions such as the operating characteristics of the arm and the size of the wrist mechanism installed at the tip of the arm.

3 After the determination in the three axial directions is completed, it can be determined that the arm tip truly interferes in the region corresponding to the Ye region (section from t1 to t2 in the figure).

Furthermore, FIGS. 10 and 11 show a fourth embodiment of the present invention.

In this example, the A for each rotation angle of the first axis is calculated based on the assumption that the arm moves over the entire range around the second axis.
This shows the position of the point.

Here, the operating range of each robot can be classified into the following three regions depending on the rotation angle of the first axis.

For Unit 1, θ, ■) <θ, fl+ Safety area (G411
) θ , Ml≦θ +I+(θl2 (I+Interference caution area (YeLI)) θ %l+≦θ, (1) Interference risk area (R31ゝ) Similarly, for Unit 2, θ , +2) <G1 (2) Safety area (G
121) θ (21 (G1 (2) ≦ θ , fi + interference risk region (Yo (2 +) G 1 C 2) ≦ θ , (21 interference risk region (R + 21)).

Then, θ, -) and G2(2) for each time are displayed on the CRT of the computer 2 along the time axis as shown in FIG. From this display, if you visually check whether the No. 1 and No. 2 cars are in the respective areas, you can judge according to the table below.

Then, from the CRT screen, the areas corresponding to the circles in the table above can be determined to be interference areas.

This interference region is shown with hatching in FIG.

In addition, when it is determined that interference will occur on the screen as in each of the above embodiments, the computer 2 shifts the arm position data at each teaching point for the first or second machine in the time axis direction ( For example, this can be achieved by shifting the start timing or temporarily increasing or decreasing the speed of the robot), displaying the shifted data, and repeating the operation of checking again for interference to prevent interference. You can grasp the timing of the movement to avoid.

Interference can also be avoided by repeating the operation of changing the teaching point and the operation of displaying and confirming the position of the robot arm after the change.

After modifying the program through the above operations, this data is written to the recording medium 9 by the storage device 3, and this recording medium 9 is loaded into the control panel 8 of each robot and played back. The robot can be operated without interference.

Furthermore, although the above embodiment describes a system equipped with two robots, even in a system equipped with a larger number of robots, by performing the same processing as in the case of two robots between adjacent robots, all robots can be It is possible to determine whether there is interference with robots.

Note that, of course, based on the above judgment, the robot may be automatically controlled to stop once it has started moving to the dangerous area.

"Effects of the Invention" As is clear from the above description, according to the present invention, data regarding the positions of the tips of the arms of a plurality of robots is displayed on a display device as a time-series graph, so that the following effects can be achieved. .

(a) It is possible to reliably recognize the presence or absence of interference in an offline state and avoid interference by processing such as shifting the start timing.

(b) Data to be displayed by performing simple arithmetic processing such as simply converting the data of the rotation angle of the robot arm as is or by converting it into an orthogonal coordinate system according to a conversion formula, and by processing to align the data in the time axis direction. is obtained.

[Brief explanation of drawings]

1 to 4 show a first embodiment of the present invention, in which FIG. 1 is a perspective view showing the overall structure of the teaching device, FIG. 2 is a plan view of the robot, and FIG. 3 is a front view of the robot. Figure 4 is an explanatory diagram of the interference area between two robots, Figure 5 is an explanatory diagram of the display contents of the screen, and Figures 6 to 8 are the second diagram of the present invention.
Fig. 6 is an explanatory diagram of the interference area of two robots, Fig. 7 is a diagram illustrating the relationship between the polar coordinate system and the orthogonal coordinate system, and Fig. 8 is an explanatory diagram of the display contents of the screen. , FIG. 9 is an explanatory diagram of the screen display contents in the third embodiment of the present invention, FIGS. 10 and 11 are diagrams showing the fourth embodiment of the present invention, and FIG. 10 is an explanatory diagram of the interference area. , FIG. 11 is an explanatory diagram of the display contents of the screen. 1 main body, 2 computer, 3 storage means, 4
- Coordinate input equipment, 7...robots, 80 hot control panels.

Claims (1)

[Claims] It has a computer that calculates data to be supplied to a robot control device that controls robots arranged in a relative relationship where the rotation ranges of their arms partially overlap with each other and performs regenerative operations. What is claimed is: 1. An offline teaching device for a robot, characterized by having a function of chronologically arranging data regarding the position of an arm, and a function of displaying the arranged data on the same screen with the same time axis.