JP3165249B2 - Motion locus creation device for welding robot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the creation of a motion trajectory of a welding robot that displays three-dimensional graphic data of a work stored in a computer storage device on a display screen and teaches the robot a motion trajectory such as a welding line. Related to the device.

[0002]

2. Description of the Related Art Conventionally _, graphic data of a work input to _a computer is displayed on a display screen, and a line segment to be welded or an air cut point is designated from among the line segments constituting the work, and a motion locus of the robot is designated. A motion trajectory creating apparatus for creating a robot and teaching a desired work operation is used for teaching a robot.

[0003]

However _, since the work graphic displayed on the display screen by _the above-mentioned conventional technique displays all the line segments of the work, some of the line segments include welding lines. Since many unrelated lines are included, it is cumbersome to select only necessary welding lines from among many lines while looking at the displayed workpiece figure, and it is erroneous. There is a problem that errors easily occur. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is directed to a welding robot capable of calculating and extracting only a welding line from a large number of line segments indicating a work figure displayed on a display screen and displaying the welding line in a divided manner. It is an object of the present invention to provide a motion trajectory creating device.

[0004]

In order to achieve the above object, a first means employed by the present invention is a line segment for performing a welding operation from the line segments constituting a work figure displayed on a display screen. A welding robot operation locus creating device for teaching a work locus of a robot by designating a welding locus of a base part in the workpiece graphic, and a part other than the base part. A tangential plane extracting means for extracting a surface in contact with the welding surface of the base part from surfaces to be welded, and an ridge line extracting means for extracting and displaying a ridge line surrounding the tangent plane. It is configured as a robot motion trajectory creation device. A second means employed by the present invention is a welding robot for designating a welding operation line segment from among the line segments constituting a work figure displayed on a display screen and teaching a work locus of the robot. In the motion trajectory creating device, a base welding surface calculation means for calculating an equation of a welding surface of a base part in the workpiece graphic, and a welding surface of the base part based on the equation and vertex coordinates of parts other than the base part. Distance calculating means for calculating the distance to each vertex of a part other than the base part; and ridge line extracting means for extracting and displaying a ridge connecting the vertices whose distance calculated by the distance calculating means is 0 or close to 0. It is configured as a motion trajectory creation device for a welding robot, characterized in that it is formed as follows.

[0005]

According to the first means of the present invention, a base part is designated from among the line segments constituting the work figure displayed on the display screen, and the welding surface of the base part is changed to the base welding surface. Calculated by the arithmetic means, and by extracting the surface in contact with the base part from among the surfaces of the other parts by the tangent plane extracting means, the ridge line surrounding the extracted tangent plane is extracted by the ridge line extracting means and is determined as a welding candidate line segment. It is displayed separately from other line segments. Therefore, the welding line can be accurately specified without being confused by a large number of other line segments due to the segment displayed. Further, according to the second means, a base part is designated from among the line segments constituting the work figure displayed on the display screen, and the vertex coordinates of the base part are input to thereby specify the base welding surface. The calculating means calculates the equation of the welding surface of the base part. The distance between the welding surface of the base part and the vertex of the other part is calculated from the equation and the vertex coordinates of the other part by the distance calculating means. The ridge line connecting the vertices whose distance calculated by the distance calculation means is 0 or close to 0 is extracted by the ridge line extraction means, and the welding candidate line segment is displayed separately from other line segments. Therefore, the welding line can be accurately specified without being confused by a large number of other line segments due to the segment displayed.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
This embodiment will be described to facilitate understanding of the present invention. still,
The following examples are examples embodying the present invention.
It is not intended to limit the technical scope of the invention. Here, Figure 1
Is the operation locus creation of the welding robot according to one embodiment of the present invention.
Block showing the configuration of the robot operation teaching device including the device
FIG. 2 and FIG. 2 to FIG.
9 to 11 show examples of changes in the welding base parts.
Illustrated illustration_,FIG. 12 shows a robot operation teaching device according to the embodiment.
FIG. The motion trajectory creating device 1 shown in FIG.
Robot operation teaching device 2 configured as shown in FIG.
Applied to That is_,The robot operation teaching device 2 is
Input by computer body 4, keyboard 6 and mouse 7
It is mainly composed of a device and a display 5.
The generated operation teaching data is transferred offline to the robot control panel.
8 and the robot 9 is controlled based on the operation teaching data.
To perform the prescribed welding work on the work 3.
It is. The robot operation teaching device 2 has a wire shown in FIG.
Model data, work condition data, robot model data
A storage device (not shown) for external input of data
I have. Based on these data, the motion trajectory creating device 1
Thus, the motion trajectory of the robot 9 is created. Operating gauge below
A procedure of creating a motion trajectory by the trace creation device 1 will be described. Figure
2 is the base part P as the base₁Part P_Two,
P_Three, P_FourShows the work model when welding
You. The number of flows shown in the motion trajectory creating device 1 of FIG.
The characters (1) to (9) correspond to the following explanation numbers. (1) A display on which the work figure shown in FIG. 2 is displayed
First, the base part P₁The graphic
The cursor. (2) Base parts P₁All faces and parts P_TwoContact with
Examine the touch. For example_,Base surface P₁₁And parts P_Twoone of
Surface P_{twenty one}Check whether or not is in contact with
You. First, the base surface P₁₁Three points from the vertex of the base plane P
₁₁Find the equation AX + BY + CZ + D = 0 Then, the part plane P_{twenty one}Vertex coordinates (Xi, Yi, Z
i) and base plane P₁₁Is obtained. Di = | AXi + BYi + CZi + D | / √ (A^Two+ B
^Two+ C^TwoFrom the above equation, if all Di <ΔD, the base plane P₁₁And parts
Plane P_{twenty one}Are considered to be in contact. Here, ΔD is 0 or 0
Is a small constant close to. Next, the part plane P_{twenty one}Ridge line surrounding
L_{twenty one}, L_{twenty two}, L_{twenty three}, L_{twenty four}Is extracted as a welding line candidate line segment
Is done. Thus, among the many line segments that compose the work figure
, Welding line candidate segments are automatically extracted. (3) The extracted edges can be distinguished from other edges.
Sea urchin_,Display in different colors and thicknesses. The same processing as the above (1), (2) and (3) is performed on the base plane P₁₁When
Each part surface P₃₁, P₄₁Also performed as shown in FIG.
Each part P_Two, P_Three, P_FourBase surface P₁₁Edge that touches
Line is welding candidate line L_{twenty one}~ L_{twenty four}, L₃₁~ L₃₄, L₄₁~ L₄₄When
To display. (4) From the extracted line segments, select only the line segment to be welded.
Welding line W with graphic cursor in the order of welding_iWhen
And select. (5) Selected welding line W_iIs displayed in an identifiable manner
You. (6) At this time, the selected welding line W_iAre welded at both ends
Start point position data W_is, And welding end point position data W_ie
Automatically stored as FIG. 4 shows the welding candidate line L _{twenty one}, L
_{twenty three}, L₃₁, L₄₁The welding line W₁, W_Two, W_Three, W_FourAs
Shows the specified example. Also_,Each welding line W₁~ W_FourStarting point position data W for each
_is, Welding end point position data W_ie, And operating conditions in between
Is set in advance as shown in Table 1.
Angles, welding conditions, etc. are stored simultaneously.

[Table 1] (7) The approach point and the retreat point provided near the welding start point and the welding end point approach the torch posture vector direction set in advance from the welding start point W _is and the welding end point W _ie as shown in FIG. , As a position separated from the retreat offset amount ΔT by the following equation. Approaching point C _is = W _is -TΔT Evacuation point C _ie = W _ie -TΔT where T is a torch attitude unit vector obtained from torch attitude angles α and β and a welding line vector. Torch attitude angle alpha, beta, as shown in FIG. _6, the angle from the base surface P ₁₁ against the weld line W _{i alpha,} further angular weld line maintain the attitude of the alpha W _i and angle on a plane including the torch beta Is defined as (8) From the retreat point C _ie to the welding line W _{1, the} next welding line W
_An interference avoidance point is determined as shown in FIG. 7 in accordance with a predetermined calculation method described below in order to determine an air-cut locus between the approach point C _{(i + 1) s} to ₂ . That is, the equation (a) of a straight line L connecting C _ie and C _{(i + 1) s} and X−X _i / 1 = Y−Y _i / m = Z−Z _i / n── (a) From the equation (b), AX + BY + CZ + D = 0── (b) The part plane P _jk intersecting with the straight line L connecting C _ie and C _{(i + 1) s}
The finding, determine the maximum height Z _m part plane P _jk crossing from the graphic data, determine the height Z _h of air cut trajectory that does not interfere with the part plane P _jk in the following equation (c). _{Z h = Z m + ΔZ── (} c) (ΔZ: constant) _Then, between the retracted point C _ie and C _{(i + 1) s,} the height of the air cut trajectory obtained above equation (c) Interference avoidance point A _j by Z _h
And A _{j + 1} are set as follows. _{C ie = (X i, Y} i, Z i) _{When, A j = (X i,} Y i, Z h) C (i + 1) s = (X i + 1, Y i + 1, Z i ₊₁ ), A _{j + 1} = (X _{i + 1} , Y _{i + 1} , Z _h ) Therefore, the torch tip trajectory is represented by C _ie , A _j , A _{j + 1} , C _{h
By connecting to (i + 1) s} , it is possible to set an air cut trajectory that does not interfere with the work 3. If C _ie and C _{(i + 1)} no part plane intersecting the straight line connecting the _S is the C _ie and C _{(i + 1) s} and connecting the direct path. Performed on W ₄ the calculation from the welding line W _1, sets the air cutting locus of the welding operations on the work model. (9) approach point from the welding line W ₁ by the end the above process,
Coordinate values of a welding start point, a welding end point, a retreat point, and an interference avoidance point are automatically created, and the robot operation trajectory data shown in FIG. 8 is displayed on the display screen. The motion trajectory data is stored in the storage device together with welding conditions and the like as work teaching data in a format as shown in Table 2.

[Table 2] The work teaching data created as described above is confirmed by robot operation simulation, converted into robot operation data, and input to the robot control panel via communication or a floppy disk. The selection of the base part can be designated as shown in FIGS. Each figure shows an example of a work model composed of _three parts P ₁ , P ₂ and P _3. FIG. 9 shows a case where part P ₁ is designated as a base part, and FIG. 10 shows a case where part P ₂ is a base part. If specified, Figure 11 shows a case where the specified parts P ₃ to the base part. Thus, by specifying the base parts,
The welding candidate line segments are extracted and set by the setting means, and are identified and displayed as shown in each figure.

[0007]

As described above, according to the present invention, a base part is designated from among the line segments constituting the work figure displayed on the display screen, and the welding surface of the base part is designated as the base part. The ridge line surrounding the extracted tangent plane is extracted by the tangent plane extracting means by calculating the welding surface calculating means and extracting the surface in contact with the base part from the surfaces of other parts by the tangent plane extracting means, and the welding candidate line Is displayed separately from other line segments. Also, by designating a base part from among the line segments constituting the work figure displayed on the display screen and inputting the vertex coordinates of the base part, the base welding surface calculation means can perform welding of the base part. Calculate the surface equation. The distance between the welding surface of the base part and the vertex of the other part is calculated from the equation and the vertex coordinates of the other part by the distance calculating means. The ridge line connecting the vertices whose distance calculated by the distance calculation means is 0 or close to 0 is extracted by the ridge line extraction means, and the welding candidate line segment is displayed separately from other line segments. Therefore, the welding line can be accurately specified without being distracted by many other line segments by the displayed segment, and the operation to reduce the burden on the operator for creating the motion trajectory by _the welding robot is reduced. A trajectory creation device can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a robot operation teaching device including a motion trajectory creating device for a welding robot according to an embodiment of the present invention.

FIG. 2 is a display diagram on a display screen of a work model according to the embodiment.

FIG. 3 is an extraction display diagram of welding candidate line segments.

FIG. 4 is an extraction display diagram of a welding line.

FIG. 5 is a display diagram showing the setting of a torch approach point and a retreat point.

FIG. 6 is an explanatory view showing setting of a torch posture angle.

FIG. 7 is an explanatory diagram showing setting of an acut point.

FIG. 8 is a display diagram showing settings of a welding line and an air cut point.

FIG. 9 is a display diagram showing a change mode of a base part setting.

FIG. 10

FIG. 11

FIG. 12 is a configuration diagram of a motion teaching device of the robot according to the embodiment.

[Explanation of symbols]

1── operation path creation device 2── operation teaching apparatus 3── workpiece 5── display W ₁ to _W-4 ── weld line P ₁ ── base part _{P 2, P 3, P 4} ── parts P ₁₁ ─ ─ base part weld surface L ₂₁ ~L ₄₄ ── weld line candidate line segments

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B23K 9/127 B25J 9/10 B25J 9/22 G05B 19/42

Claims (2)

(57) [Claims] An operation locus creating apparatus for a welding robot for designating a welding work line from among the lines constituting a work figure displayed on a display screen and teaching a work locus of the robot. A base welding surface calculation means for calculating a welding surface of a base part in the figure;
A tangent plane extracting means for extracting a surface that is in contact with the welding surface of the base part from among the surfaces constituting the work other than the base part; and a ridge line extracting means for extracting and displaying a ridge line surrounding the tangent plane. An operation locus creating device for a welding robot, comprising: 2. An operation locus creating apparatus for a welding robot for designating a welding work line from among line segments constituting a work figure displayed on a display screen and teaching a work locus of the robot. Base welding surface calculation means for calculating the equation of the welding surface of the base part in the figure, and each vertex of the welding surface of the base part and the work other than the base part from the equation and the vertex coordinates of the work other than the base part And a ridge line extracting means for extracting and displaying ridges connecting vertices whose distance calculated by the distance calculating means is 0 or close to 0. Motion trajectory creation device for welding robots.