JPH07104702B2 - Off-line teaching method for robots - Google Patents

Description

The present invention relates to an off-line teaching method for a robot, which teaches the operation of a robot arm by using images of a robot and a work without using the robot body.

(Prior Art) When teaching the operation of the arm of a robot, the robot body is often used. However, there is a problem that the operating rate of the robot is lowered because the robot cannot be made to work during the teaching. In order to solve this problem, the images of the work and the end effector of the robot are displayed on the CRT screen without using the robot body,
An off-line teaching method for teaching the operation of the end effector while moving the end effector on the screen may be adopted. In the off-line teaching method, generally, the shape of the work is displayed using a line segment (outline) that represents the outer shape of the work.

(Problems to be solved by the invention) Since the work path (work line) on the work corresponds to a part of the contour line that displays the shape of the work, when the work has a complicated shape, many lines are drawn. It was difficult to recognize the line segment to be taught as the work route from among the minutes. Therefore, it is difficult for the operator to accurately move the end effector on the screen to the work path of the work.

(Object of the Invention) The present invention has been made in order to solve the above-mentioned problems in the prior art, and offline teaching that makes it easy to accurately move the end effector of the robot to the work path of the work on the screen. The purpose is to provide a method.

(Means for Solving the Problems) In order to solve the above problems, in the first configuration of the present invention, the offline teaching of the robot that teaches the operation of the robot using the image of the work displayed on the image display means In the method, the image display means displays the outline of the work and the work line indicating the work path of the end effector of the robot by using different types of lines.

Moreover, in the 2nd structure of this invention, among the said work lines,
The work line portion that has been taught is displayed using a different type of line from the work line portion that has not been taught.

Further, in the third configuration of the present invention, in the robot off-line teaching method for teaching the operation of the robot by using the image of the work displayed on the image display means, the image display means includes the end effector portion of the robot. When,
The end effector among the points selected in advance on the work line when displaying the contour line of the work and the work line indicating the work path of the end effector and starting teaching along the work line The working point of the end effector portion is automatically moved to a point closest to the working point of the portion.

(Operation) If the outline of the work and the work line are displayed using different types of lines, the operator can easily distinguish these lines.

Further, by displaying the taught work line portion using a line of a different type from the work line portion before teaching, the operator can easily recognize only the work line portion before teaching.

Further, when starting teaching, if the work point of the end effector portion is automatically moved to one point on the work line, it is possible to save the trouble of finding a work line to be taught from among many lines on the screen. You can

(Examples) A. Schematic configuration of robot system Fig. 1 is a schematic perspective view showing a configuration of a welding robot system as a robot to which the present invention is applied to teach the operation of a robot. This welding robot RB has two bases 1a
Columns 2a and 2b that are vertically erected on and 1b respectively
Further, a beam 3 extending in the Y direction is installed on top of the columns 2a and 2b. A moving beam 4 that extends in the X direction and is movable in the Y direction by the motor M ₁ is provided on the beam 3. The moving beam 4 can be moved in the X direction by a motor (not shown). A moving column 5 is provided at one end of the moving beam 4 and extends in the Z direction and is movable in the Z direction by a motor (not shown).

An arm 6 is provided at the lower end of the moving column 5, and a welding torch T as an end effector is provided at the tip of the arm 6. The arm 6 rotates about the vertical axis in the θ _R direction, and the tip portion of the arm 6 including the welding torch T rotates in the ψ direction. As a result, the position and orientation of the torch T are determined by the five coordinates X, Y, Z, θ _R and ψ.

The welding robot RB is provided with a positioner PS as an external shaft system for changing the position and posture of the work. The positioner PS has support columns 11a and 11b which are vertically installed on the bases 1a and 1b of the robot RB, and a U-shaped beam 12 is pivotally supported on the support columns 11a and 11b. . The U-shaped beam 12 is rotated in the φ direction about a horizontal axis by a motor M ₂ attached to the support column 11a. Further, on the central part of the beam 12, the rotating jig 13
Is mounted on the rotating jig 13 on the upper part of the rotating jig 13.
a is driven by a motor (not shown) and rotates in the θ _P direction. The work is installed on the rotary table 13a, and the relative position and posture of the work with respect to the welding robot RB are appropriately changed so that the welding robot RB can easily perform the work. That is, the work is rotated in the φ direction and the θ _P direction by the positioner PS, so that the torch T is set in such a position and posture that the torch T can easily move with respect to a desired welding line on the work.

The operation of the welding robot RB is controlled by the robot control board 20. Further, in the example of the figure, the operation of the positioner PS is also controlled by the robot control panel 20. That is, the robot control panel 20 stores teaching data including the coordinate values of the X, Y, Z, θ _R and ψ axes of the welding robot RB and the coordinate axes of the θ _P and ψ axes of the positioner PS. The operation of the torch T and the operation of the positioner PS are controlled according to this teaching data.

A personal computer 30 as an offline teaching device is connected to the robot control panel 20. The personal computer 30 includes a CRT 31, a keyboard 32, a mouse 33, a hard disk 34, a printer 35, and the like. First of all, the operator
Using 30, the teaching data is created without operating the welding robot RB main body, and the created teaching data is transferred to and stored in the robot control panel 20.

B. Operation of the Embodiment FIG. 2 is a flowchart showing the operation procedure of the embodiment. First, in step S1, the shape data of the work, the relative position and orientation data of the work with respect to the welding robot RB, the work line data, and the like are input by the operator using the keyboard 32.

FIG. 3 is a perspective view showing a work W used in this embodiment. The work W is a rectangular flat plate 41 on which a square-shaped frame-shaped plate 42 is placed. Then, the frame plate 42
Two lines C ₁ and C _{2 at} which the lower surface of the plate and the flat plate 41 are in contact are objects to be taught as work lines (welding lines).

In step S1, as the shape data of the work W, the coordinate values of the points P ₁ , P ₂ , P _3, ... At both ends of all the line segments L ₁ , L ₂ ... That is, the shape of the workpiece W is stored as a set of these line segments L ₁ , L _2, ... The coordinate values of these end points P ₁ , P ₂ , P ₃ ... Are coordinate values on the work system coordinates (X _W , Y _W , Z _W ) with respect to a predetermined reference position (for example, point P ₁ ) on this work W. Given.

Further, as the data of the relative position and orientation of the work W with respect to the welding robot RB, the installation position of the work W on the turntable 13a and the initial values of the coordinates of the θ _P axis and the φ axis of the positioner PS (for example, both 0゜) etc. are entered.

The coordinate values of the end point P ₅ to P ₈ and P ₉ to P ₁₂ of the working lines C ₁ and C ₂ are inputted to distinguish the coordinates of the other endpoint. Then, the coordinate values of the end points of the work lines C ₁ and C ₂ are used as work line data, and the coordinate values of the end points of the other contour lines of the work are treated as contour line data. Work shape data file).

Next, in step S2, the system data is input or changed. The system data includes the main shape data of the welding robot RB and the positioner PS, the axis configuration and each axis (X,
It includes data indicating the movable range of Y, Z, θ _P , ψ) and (θ _P , φ). The main shape data is used for checking the interference between the work W and the robot RB in the step described later.
This is data for displaying the main shapes of the robot RB and positioner PS on the CRT31. In this embodiment, the arm 6 and the beam 12 are the main shape data.
Also, data indicating the outer shape of the turntable 13a or the like is input. The system data input in step S2 is always constant if the robot RB and the positioner PS are the same, so once the data is set, the hard disk 34
It is not necessary to input from the keyboard 32 each time teaching is performed, if it is stored in the memory.

Next, in step S3, the work W and the torch marker are set.
Display on CRT31. 4A to 4C are views showing images displayed on the CRT 31 in this embodiment.
The figure shows a stereoscopic image of the work W and the torch marker M displayed in step S3. The image of the work is represented by the outlines L ₁ , L ₂ ...

Of the outlines representing the work, the line segments LC ₁ , LC ₂ ... That belong to the work lines C ₁ , C ₂ are displayed as different types of lines from the other line segments as shown in FIG. 4A. . For example, work lines C ₁ and C ₂
Are shown in red and the other outlines are shown in blue. The background of the screen is black, for example. Thus displaying the working line C _1, C ₂ in another outline with different colors, the operator can easily recognize the working line C _1, C _2.

The torch marker M is a marker conceptually showing the working point CP of the torch T tip of the welding robot RB and the attitude of the torch T.
In FIG. 4A, the work point CP is shown at the apex of the triangular pyramid, and the attitude of the torch T is shown at the attitude of the triangular pyramid. The shape of the torch marker M may be a triangular pyramid, a cone or a simple arrow, as long as its posture and the position of the work point CP can be specified.

In step S4, the working point CP at the tip of the torch marker M is moved to the first working line C ₁ . This may be done manually by the operator, but it can be done automatically by either of the following two methods.

In the first method, out of the working line C ₁ on the end point P ₅ to P _8, the nearest terminal point P from the previous state (this case is Figure 4A) position of the working point CP of Tochimaka M in step S4 ₅ Move the work point CP to. FIG. 4B is a diagram showing an image after moving the torch marker M according to this method.

In the second method, the work point CP is moved to a point closest to the work point CP of the torch marker M among arbitrary points on the work line C ₁ . This "closest point" is the working point CP of the torch marker M
Is the shortest distance from the work point CP among the points perpendicular to the line segments LC _{1 to} LC ₄ on the work line C ₁ . In addition,
Illustrations corresponding to this case are omitted.

The personal computer 30 of this embodiment can use both of the above two methods. For example, a menu screen showing various teaching work items is displayed on the CRT 31, and the operator uses the mouse 33 or the like to select one of the above two methods from the items displayed on the screen. Then, the personal computer 30 moves the torch marker M according to the selected method. As a result, for example, the image as shown in FIG. 4B is displayed on the CRT 31.

In step S5, the operator teaches the operation of the torch marker M along the work line C ₁ while watching the images of the work W and the torch marker M displayed on the CRT 31. For example, first, the attitude of the torch marker M is appropriately adjusted at the first point P ₅ of the work line C ₁ . The posture of the torch marker M is adjusted by pushing a switch for posture change (not shown) provided on the mouse 33. Torch marker M at point P ₅
When the position and orientation of is determined, the position / orientation data indicating this is stored in the personal computer 30 as teaching data. Incidentally, the position and orientation data work coordinate system _{(X W, Y W, Z} W) is stored as data indicating the coordinates and directions in. When the teaching at the point P ₅ is completed, the torch marker M on the CRT 31 is then moved to the line segment LC ₁ using the mouse 33.
Then, the teaching data is created and stored by appropriately adjusting the position and posture of the torch marker M at arbitrary points between points P ₅ and P ₆ by moving the torch marker M.

Incidentally, Tochimaka M on the working line C ₁ in the step S4
Once is moved, the operator can easily track the work line C ₁ to be taught on the CRT screen.
Therefore, in the line segment LC ₁ , the operation of sequentially moving the torch marker M over several points between the points P ₅ and P ₆ can be easily performed using the mouse 33 or the like as described above.

The 4C diagram is a diagram showing an image at the time of creation of the teaching data to the point P ₁ of intermediate on line LC ₁ is completed. As shown in this figure, the work line part (line segment ▲
▼) is displayed as a line of a type different from the outlines of other work line portions and work for which teaching has not been completed. For example, the line segment ▼ is displayed in yellow so that it can be easily distinguished from other work lines displayed in red and the outline of the work displayed in blue. In this way, the operator can easily recognize the work line portion for which the teaching has been completed, so that the operator may forget to teach part of the work route,
There is an advantage that teaching is not repeated.

Thus, by repeating the same teaching operation in each segment LC ₁ Lc ₄ on the work line C _1, to the working line C ₁ is formed by a line segment LC ₁ Lc _4, the operation of the torch T Is taught. Teaching the position and orientation of the torch T along the work line C ₁ in this way is referred to as “teaching the work path” in this specification. In step S5, in addition to teaching the work route, the torch marker M is also taught along with welding conditions such as the speed of the torch T, welding current, and welding voltage.
Created as teaching data together with the position and orientation data of. Remembered. Hereinafter, the teaching in step S5 will be referred to as "work system teaching".

When the teaching of the work line C ₁ is completed, the process returns from step S6 to S4, and the work route is similarly taught to the next work line C ₂ .

In step S7, the teaching data of the work coordinate system created in step S5 is converted into teaching data of the robot coordinate system. In this conversion, the installation position data of the work W on the rotary table 13a input in step S1 is also used. Further, in step S7, the shape data of the work W is also converted into the robot coordinate system.

In step S8, based on the shape data of the work W converted into the robot coordinate system and the main shape data input in step S2, the main shape of the positioner PS, the work W and at least the solid of the end effector portion of the welding robot RB are solidified. Image is displayed on CRT31. FIG. 5 is a diagram showing an image at this time. As the main shape of the positioner PS, only the beam 12 and the turntable 13a are shown. However, the images of the beam 12 and the turntable 13a are displayed as approximate shapes for simplicity. Although the image of the arm 6 including the torch T is displayed as the stereoscopic image of the robot, the torch marker M may be displayed for simplicity.

In step S9, the teaching data is corrected. For example, on the screen of the CRT 31, the torch marker M is automatically moved according to the teaching data, whether the movement of the torch marker M is within the movable range of the torch T, and the torch T interferes with the work W, the beam 12, etc. , "Mechanical interference"
Call. ) Is checked. If the torch T has some trouble in its movement, the operator appropriately changes the teaching data such as the coordinate value of the positioner PS using the keyboard 32 to cause the torch T to be in the movable range and cause mechanical interference. Be able to move without. Then, when the teaching data is corrected until the torch T (that is, the torch marker M) can move within the movable range without causing mechanical interference, the teaching is finished over the entire work lines C ₁ and C ₂ .

C. Modifications The present invention is not limited to the above embodiments, and the following modifications are possible, for example.

In the above-described embodiment, the work line before teaching is displayed in red, the work line after teaching is displayed in yellow, and the other outlines of the work are displayed in blue. However, these are not different colors, but thick lines, thin lines, solid lines, broken lines, and one point. It may be distinguished by a chain line or a dotted line. That is,
The work line before teaching, the work line after teaching, and the other outline may be displayed using different types of lines.

In the above embodiment, the shape data of the work and the like are input using the keyboard 32, but the shape data and the like created beforehand by using another CAD system or the like may be transmitted to the personal computer 30 and used.

In order to move the torch marker M to one point on the work line, the method is not limited to the first and second methods described above. Of the points selected on the work line, the torch marker M is moved to the closest point from the work point CP. You can do it.

(Effects of the Invention) As described above, according to the first configuration of the present invention,
Since the operator can easily distinguish the work outline displayed on the image display means from the work line, there is an effect that the end effector can be accurately moved on the work line on the screen.

Further, according to the second configuration of the present invention, the work line portion before teaching can be easily distinguished from the work line portion after teaching,
There is an effect that it becomes easier to move the end effect along the work line portion before teaching.

Further, according to the third configuration of the present invention, when starting teaching, the working point of the end effector portion is automatically moved to one point on the working line, so teaching should be performed from among many lines on the screen. You can save the trouble of finding a work line,
There is an effect that the end effector can be easily moved to the work line.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing the configuration of a robot to which the present invention is applied, FIG. 2 is a flow chart showing the operation of the embodiment, FIG. 3 is a perspective view showing a workpiece, FIGS. 4A to 4C, and FIG. FIG. 5 is a conceptual diagram showing an image in the embodiment. RB ... Welding robot, PS ... Positioner, T ... Welding torch,
M ... Tochimaka, C _1, C ₂ ... work line, 6 ... arm, L _1,
L ₂ … Outline, 30… Personal computer

Claims (3)

[Claims] 1. An off-line teaching method of a robot for teaching a motion of a robot by using an image of a work displayed on an image display means, wherein the image display means includes an outline of the work and an end of the robot. An off-line teaching method for a robot, characterized in that a work line indicating a work path of an effector is displayed by using different types of lines. 2. The off-line teaching method for a robot according to claim 1, wherein among the work lines, the taught work line portion is displayed using a line of a different type from the work line portion before teaching. 3. An off-line teaching method for a robot, which teaches the operation of a robot using an image of a work displayed on an image display means, wherein the image display means includes an end effector portion of the robot and an outer shape of the work. A line and a work line indicating the work path of the end effector are displayed, and when starting teaching along the work line, among the points selected in advance on the work line, the work point of the end effector portion. An off-line teaching method for a robot, wherein the working point of the end effector portion is automatically moved to a point closest to