JP3190737B2 - 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 for displaying three-dimensional graphic data of a work stored in a computer storage device on a display screen and automatically teaching the robot the motion trajectory of welding work. Related to the device.

[0002]

2. Description of the Related Art Conventionally _, graphic data of a workpiece input to _a computer is displayed on a display screen, and a plurality of welding lines to be welded are selected from among the line segments constituting the workpiece, and each welding line is selected. An operation trajectory creating apparatus for creating an operation trajectory of a robot for moving a welding torch in welding order in order to teach a desired work operation is used for teaching the robot.

[0003]

However _, the task of extracting a plurality of welding lines from a work figure displayed on a display screen and teaching the motion trajectory of the robot with respect to each welding line by _the above-described prior art is complicated. In particular, there has been a problem that a large amount of labor is required particularly for accurately setting the air cut point so that the welding torch does not interfere with the work. The present invention has been made in view of the above-described problems, and automatically calculates a motion trajectory when a robot performs a welding operation on a plurality of welding lines in a work figure displayed on a display screen. It is an object of the present invention to provide an operation trajectory creation device for a welding robot that can perform the operation trajectory.

[0004]

A first means adopted by the present invention to achieve the above object is to teach a work locus of a robot including a welding line in a line segment constituting a given work figure. In the motion trajectory creation device of the welding robot,
The direction of the welding surface of the base part in the workpiece figure
A base welding surface calculating means for calculating the equation;
From the vertex coordinates of the work other than the base parts
Between the welded surface of the workpiece and each vertex of the workpiece other than the base part
Distance calculating means for calculating a distance, and the distance calculating means
The ridge line connecting the vertices whose calculated distance is 0 or close to 0
Edge line extraction means to extract and display as welding line candidate line segments
And welding start / end point calculating means for calculating a welding start point and a welding end point for a welding line to be welded among the extracted welding line candidate segments, and a welding start point and a welding end point based on the welding start point and the welding end point. The approach point / evacuation point calculation method storage means for storing the approach point / evacuation point calculation method, and interference when the moving line from the evacuation point of each welding line to the next welding line approach point interferes with the workpiece. Means for storing an interference avoiding point calculating method for storing a method for calculating an interference avoiding point capable of avoiding the welding, and data of a welding start point and a welding end point for all the welding lines obtained by the welding start point / end point calculating means. Applying the calculation method stored in the approach point / evacuation point calculation method storage means to calculate the approach point data and the evacuation point data for all the welding lines, and also saves the evacuation point data and the approach point data for each welding line to the interference. A first total motion trajectory automatic calculating means for calculating interference avoidance point data for all welding lines by applying to the calculating method stored in the avoidance point calculating method storage means to obtain all motion trajectories; It is configured as a motion trajectory creating device for a welding robot. The second means for the present invention is employed, the operation trajectory creation unit of a welding robot for teaching the working path of the robot, including the weld line in the line segments comprising the given part geometry, the word
The equation of the welding surface of the base part in the
Base welding surface calculation means for calculating
Of the base part from the vertex coordinates of the work other than
The distance between the welding surface and each vertex of the workpiece other than the base part
Distance calculating means for calculating, and calculating by the distance calculating means
The ridge connecting the vertices whose distance is 0 or close to 0 is the welding line
Extracted as a candidate line, and the ridge line extracting means to display, extract
A welding start point and a welding start point for calculating a welding start point and a welding end point for a welding line to be welded among the candidate welding line segments output.
An end point calculating means, and a point which is separated from each welding start point and each welding end point by a predetermined distance in the direction of the posture vector of the welding torch stored in advance is obtained as an approach point and a retreat point with respect to each welding start point and each welding end point. An approach point / evacuation point calculating means, an equation of a moving line connecting the evacuation point of each welding line and an approaching point of the next welding line is obtained, and the presence or absence of a work intersecting the moving line is obtained from the work graphic data. When the moving line interferes with the work, an interference avoiding point calculating means for obtaining a moving line position which does not interfere with the work as an interference avoiding point, and a welding start for all welding lines obtained by the welding start point / ending point calculating means. The approach point / evacuation point calculation means calculates approach point data and evacuation point data for all the welding lines from the data of the welding point and the welding end point, as well as evacuation point data and contact points for each welding line. A second operation trajectory automatic calculation means for calculating interference evasion point data for all welding lines from the point data by the interference evasion point calculation means to obtain all operation trajectories. It is configured as a motion trajectory creation device for a welding robot.

[0005]

According to the first means of the present invention, first, a work graphic
The equation of the welding surface of the base part inside is the base welding
It is calculated by the surface calculation means. This equation and the base par
From the vertex coordinates of workpieces other than
The welding surface of the base part and the work other than the base part
The distance from each vertex is calculated. By this distance calculating means
The ridge connecting the vertices whose calculated distance is 0 or close to 0 is a ridge
It is extracted as a candidate line segment of the welding line by the line extracting means.
For each welding line to be welded among the extracted welding line candidate segments, a welding start point and a welding end point for specifying a welding position on the welding line are calculated by welding start point / end point calculation means. Is done. Next, the calculated welding torch approaching point and retracting point with respect to the welding start and end points of each welding line, and moving the welding torch from the retracting point of each welding line to the approaching point of the next welding line. The interference avoidance point at the time of the operation is calculated and stored by the first full motion trajectory automatic calculation means. For the calculation of the approach point and the evacuation point, the calculation method stored in the approach point / retreat point calculation method storage means for storing the calculation method for calculating the direction and the distance based on the preset calculation conditions is applied. . Also, the calculation of the interference avoidance point is performed when the welding torch is moved from the retreat point of each welding line to the approaching point of the next welding line and the moving line interferes with the workpiece. The calculation method stored in the interference avoidance point calculation method storage means for storing the method of calculating the avoidance point is applied. The second means of the present invention is grasped in the manner embodying the first means, above
The welding start point and welding end point are calculated by the welding start point / end point calculation means for the given welding line . Next, an approach point when approaching the welding torch to each welding start point and a retreat point when retracting the welding torch from each welding end point are determined by a predetermined distance in the direction of the posture vector of the welding torch stored in advance. Is calculated. Next, when moving the welding torch from the retreat point of each welding line to the approaching point of the next welding line, it is determined whether or not the workpiece interferes with the moving lines. First, the equation of the moving line is obtained, and the presence or absence of a work intersecting with the moving line coordinates is obtained from the work graphic data. If there is a work that interferes with the moving line, an interference avoidance point for moving the moving line to a position that does not interfere with the work is calculated. By connecting the welding start point, welding end point, approach point, retreat point, and interference avoidance point calculated as described above with respect to all the welding lines in the order of welding, the motion locus of the robot is automatically created.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention. still,
The following embodiments are examples embodying the present invention and do not limit the technical scope of the present invention. Here, Figure 1
1 is a block diagram showing the configuration of a robot operation teaching device including a welding robot operation locus creation device according to one embodiment of the present invention. FIGS. 2 to 8 are explanatory diagrams showing the procedure of an operation locus creation according to the embodiment. 9 is a configuration diagram of a robot operation teaching device according to the embodiment. The motion trajectory creating device 1 shown in FIG.
Is applied to the robot operation teaching device 2 having the configuration as shown in FIG. That is _{, the} robot operation teaching device 2 is mainly composed of a computer main body 4, an input device using a keyboard 6 and a mouse 7, and a display 5, and the created operation teaching data is inputted to the robot control panel 8 offline. Then, the robot 9 is operated based on the operation teaching data, and a predetermined welding operation is performed on the work 3. The robot operation teaching device 2 is provided with a storage device (not shown) to which work model data, work condition data, and robot model data shown in FIG. The motion trajectory of the robot 9 is created by the motion trajectory creation device 1 based on these data. Hereinafter, a procedure of the motion trajectory creation by the motion trajectory creation device 1 will be described. The motion trajectory creating apparatus 1 according to the present embodiment is configured to be able to execute motion trajectory creation including extraction of welding lines for a plurality of parts P _{1 to} P ₄ constituting the work 3. FIG. 2 shows a base part P _{1 serving} as a base and a part P ₂ ,
A work model when welding P ₃ and P ₄ is shown. The numbers (1) to (9) of the flow shown in the motion trajectory creating apparatus 1 of FIG. 1 correspond to the following explanation numbers. (1) On the display on which the work graphic shown in FIG. 2 is displayed, first, a part as a base of the welding work is designated. Here, it is specified in the graphics cursor parts P ₁ as the base part. (2) The base part P specified by the above specifying operation
The presence or absence of a part that contacts all the surfaces of ₁ is checked. The presence or absence of contact, for _example, whether the one face P ₂₁ of the base surface P ₁₁ and part P ₂ is in contact is determined by the following calculation.

[0007] First, by selecting the three points from the vertices of the base surface P _11, equations of the base surface P ₁₁ is calculated. AX + BY + CZ + D = 0 Then, the vertex coordinates of the part surface P ₂₁ (Xi, Yi, Z
i) the distance Di between the base surface P ₁₁ is calculated. Di = | AXi + BYi + CZi + D | / √ (A ² + B
If the ² + C ²⁾ the above equation the total Di <[Delta] D, the base surface P ₁₁ and part surface P ₂₁ is considered in contact. Here, ΔD is 0 or a small constant close to 0. By the above calculation, the ridge lines L ₂₁ , L ₂₂ , L ₂₃ , L ₂₄ surrounding the part plane P ₂₁ are extracted as welding line candidate segments. In this way, welding line candidate line segments are automatically extracted from among many line segments constituting the work figure (FIG. 3). (3) Subsequently, the extracted ridge lines L ₂₁ , L ₂₂ , L ₂₃ , L ₂₄
So it can be distinguished from other edge _line, is displayed in a different color and thickness. (1) (2) be performed for the base surface P ₁₁ and each part surface P _31, P ₄₁ the same processes as (3), each part P ₂ as shown in FIG. 3, P _3, P ₄ is ridge in contact with the base surface P ₁₁ is extracted, welding candidate lines L ₂₁ ~L
Is displayed as _{24, L 31 ~L 34, L} 41 ~L 44. (4) from the extracted line segments are selected as a weld line W _i in the graphics cursor only the order in which the welding line to perform the welding. (5) The selected welding line W _i is displayed so as to be identifiable. FIG. 4 shows an example in which welding candidate lines L ₂₁ , L ₂₃ , L ₃₁ , and L ₄₁ are designated as welding lines W ₁ , W ₂ , W ₃ , and W ₄ and are identified and displayed. (6) Next, each welding line W _i selected as described above
The welding start point and welding end point are set for. When the welding start point and welding end point between the end points of each welding line W _i as each weld line W location coordinates welding start point position data W of the end points of the _{i IS} and welding end point position data W _ie Automatically stored. When setting the position of the welding start point and welding end point with respect to each weld line W _i in a position other than the end points of the weld line W _i is stored in advance the calculation method, calculation according to this method (calculation formula) As a result, the welding start point and the welding end point are calculated, and the welding start point position data W _is and the welding end point position data W _ie are automatically stored in the same manner as described above.

As described above, each welding line W₁~ W_FourEvery
Calculated welding start point position data W _isAnd welding end point
Position data W_ieIs stored in advance as shown in Table 1.
At each set welding start point and each welding end point
Attitude of welding torch, welding conditions, etc. are stored simultaneously.
You. The torch posture angles α and β are as shown in FIG._,Welding line
W_iBase plane P₁₁From angle α_,Furthermore, the angle α
Welding line W to maintain posture_iAngle β on the plane containing
Is defined as

[Table 1] (7) The setting of the approach point and the retreat point of the welding torch provided near the welding start point and the weld end point is calculated based on the approach point / retreat point calculation method stored in advance.

That is, as shown in FIG. 6, the approach / retreat offset amount Δ is calculated from the welding start point W _is and the welding end point W _{ie in the} direction of the previously set torch posture vector by the following equation.
It is calculated as a position separated by T. 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. (8) The movement trajectory of the welding torch from the retreat point set for each welding line to the approaching point of the next welding line is determined in advance as an air cut trajectory in which the welding torch does not interfere with the workpiece. The calculation is performed as follows based on the calculation method stored in the interference avoidance point calculation method storage means. As shown in FIG. 7, indicating an example of the movement to approach point of the welding wire _{W 2 C (i + 1)} s from the retreat point C _ie the weld line W _1, first, approaching the point C and the retracted point C _ie Equation (a) of a straight line L connecting _{(i + 1) s}
When an _{X-X i / 1 = Y} -Y i / m = Z-Z i / n── (a) from the equations of the part plane (b) AX + BY + CZ + D = 0── (b) retracting the point C _ie close Find the part plane P _jk that intersects with the straight line L connecting the point C _{(i + 1) s} , find the maximum height Z _m of the intersecting part plane P _jk from the graphic data, and use the air cut that does not interfere with the part plane P _jk calculating a height Z _h locus in the following equation (c). _{Z h = Z m + ΔZ── (} c) (ΔZ: constant) _Next, retracted point C _ie the approach point C _{(i + 1)} between _s, the air cut trajectory obtained above equation (c) The interference avoidance points A _j and A _{j + 1} are calculated from the height Z _h 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, when the interference avoidance points A _j and A _{j + 1} are calculated, the torch tip trajectory is calculated as C _ie , A _j , A _{j + 1} , and C _{(i + 1) s} are connected 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 a path connecting C _ie and C _{(i + 1)} and _s directly.

[0010] performed for W ₄ the calculation from the welding line W _1, air cutting locus of the welding operation for the workpiece model is set. (9) All welding start points, welding end points, approach points, retreat points, and interference avoidance points for all the welding lines obtained by the operation locus calculations shown in the above (6) to (8) are arranged in the order of the welding lines. The entire motion trajectory obtained by the connection is displayed on the display screen as robot motion trajectory data shown in FIG. 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. In the above explanation, (1) ~
Although the creation of the motion trajectory for the welding line extracted in the process (5) has been described, this is merely an example, and the method of giving the welding line may be a method of giving the welding line one by one using a mouse or the like. .

[0011]

As described above, according to the present invention, the automatic
By specifying a welding position for a welding line to be welded among the welding line candidate lines extracted in a sequential manner, a welding start point and a welding end point are determined based on welding conditions and a calculation method stored in advance. An approach point and a retreat point of the welding torch and an interference avoiding point for preventing the movement line of the welding torch from moving and the workpiece are calculated, and the calculated welding start point, welding end point, approach point, and retreat point are calculated. An operation trajectory in which points and interference avoidance points are connected in the order of welding is automatically created. Therefore,
The conventional operation of creating a complicated motion trajectory is simplified, and there is an effect that the operation trajectory of the welding robot can be created without requiring skill.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a robot operation teaching device including a welding robot operation locus creating device 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 an explanatory diagram showing the setting of the posture angle of the torch.

FIG. 6 is an explanatory diagram showing the setting of the approach point and the retreat point of the torch.

FIG. 7 is an explanatory diagram showing the setting of an interference avoidance point.

FIG. 8 is a display diagram showing a setting of a welding line and an interference avoidance point.

FIG. 9 is a configuration diagram of a motion teaching device of the robot according to the embodiment.

[Explanation of symbols]

1──Operation locus creation device 2──Operation teaching device 3──Work 5──Display W _{1 to} W ₄ ──Weld line W _{1s to} W _4s ──Weld start point W _{1e to} W _4e ──Weld end point C _{1s to} C _4s ── Approach point C _{1e to} C _4e ── Evacuation point A _{1 to} A ₄ ── Interference avoidance point

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-3-25507 (JP, A) JP-A-60-195615 (JP, A) JP-A-4-169904 (JP, A) JP-A 64-64 84310 (JP, A) JP-A-61-128107 (JP, A) JP-A-6-31450 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G05B 19/4093, 19 / 4097 B23K 9/127

Claims (2)

(57) [Claims] An operation locus creation device for a welding robot for teaching a work locus of a robot including a welding line in a line segment constituting a given workpiece graphic, wherein the welding surface of a base part in the workpiece graphic is Process
A base welding surface calculating means for calculating an equation, and a vertex coordinate of a work other than the equation and the base part.
The weld surface of the base part and the work other than the base part.
Distance calculating means for calculating the distance to each of the vertices, and the distance calculated by the distance calculating means becomes zero or zero.
A ridge line connecting close vertices is extracted as a welding line candidate line segment.
Ridge line extracting means for displaying, welding start point / end point calculating means for calculating a welding start point and a welding end point for a welding line to be welded among the extracted welding line candidate line segments, An approach point / evacuation point calculation method storage means that stores the approach point / evacuation point calculation method based on the end point, and the movement line from the evacuation point of each welding line to the next welding line approach point interferes with the workpiece. Means for calculating an interference avoidance point capable of avoiding interference, an interference avoidance point calculation method storage means, and a welding start point and a welding point for all welding lines obtained by the welding start point / end point calculation means. By applying the data of the end point to the calculation method stored in the approach point / retreat point calculation method storage means, the approach point data and the retreat point data for all the welding lines are calculated, and the retreat point data and the retreat point data for each of the weld lines are calculated. A first all motion trajectory automatic calculation means for calculating the interference avoidance point data for all welding lines by applying the near point data to the calculation method stored in the interference avoidance point calculation method storage means and obtaining all the motion trajectories; A motion trajectory creating device for a welding robot, comprising: 2. A motion trajectory creation device for a welding robot, which teaches a work trajectory of a robot including a welding line in a line segment constituting a given workpiece graphic, wherein a welding surface of a base part in the workpiece graphic is formed. Process
A base welding surface calculating means for calculating an equation, and a vertex coordinate of a work other than the equation and the base part.
The weld surface of the base part and the work other than the base part.
Distance calculating means for calculating the distance to each of the vertices, and the distance calculated by the distance calculating means becomes zero or zero.
A ridge line connecting close vertices is extracted as a welding line candidate line segment.
Ridge line extraction means to be displayed, welding start point / end point calculation means for calculating a welding start point and a welding end point for a welding line to be welded among the extracted welding line candidate segments, Approach / retreat point calculating means for finding a point at a predetermined distance from the welding end point in the direction of the posture vector of the welding torch stored in advance as an approach point and a retract point with respect to each welding start point and each welding end point; The equation of the moving line connecting the evacuation point of the next welding line and the approaching point of the next welding line is obtained, and the presence or absence of the work intersecting the moving line is obtained from the work graphic data. Avoidance point calculating means for obtaining a moving line position which does not interfere with the welding as an interference avoidance point, and a data from the welding start point and welding end point for all the welding lines obtained by the welding start point / end point calculating means. Interference for all welding line by the approach point-saving point Starring Sante stage while calculating the approach point data and saving point data for all the weld line, by the interference avoidance point calculating means from the retracted point data and access point data for each weld line A motion trajectory creating apparatus for a welding robot, comprising: second full motion trajectory automatic calculation means for calculating avoidance point data to obtain all motion trajectories.