JP4498072B2 - Setting method of positioner for welding robot - Google Patents

Description

The present invention relates to a method of setting a welding robot positioner which the workpiece can be accurately positioned in the positioner for supporting safe and short at the time of performing the automatic welding to the workpiece using a welding robot.

  A positioner for supporting a workpiece in robot welding generally has a maximum of two orthogonal axes, and the optimum welding angle is determined by adjusting the inclination angles of the two axes.

  11 and 12 are cross-sectional views showing typical weld plate surfaces in horizontal fillet welding and downward fillet welding, respectively. 11 and 12, the base material surface 55 and the upright plate surface 56 intersect each other at a right angle. In such a case, the optimum welding posture can be easily determined.

  However, the weld plate surface in the actual workpiece is not necessarily parallel or orthogonal to the axis of the positioner, and the optimum weld plate surface for welding is not always present, so an approximate value may be substituted. There may be a plurality of optimum values or approximate values. Therefore, the positioning operation of the positioner using the conventional positioning method for visually adjusting the tilt axis and the rotation axis of the positioner has been extremely difficult.

  13 and 14 are explanatory views showing an example of an actual work, FIG. 13 is a perspective view of the work, and FIG. 14 is a front view of FIG. In FIG. 13, this work has a plurality of horizontal surfaces, vertical surfaces, and inclined surfaces. In order to weld a line that intersects each surface, the line that intersects each surface is selected as a valley of the weld line, and the tilt angle of the workpiece that can obtain the optimum welding posture in robot welding, that is, the positioner shaft that supports the workpiece It is necessary to determine the inclination angle, and the determination method is extremely complicated. In FIG. 13, the first axis and the second axis of the positioner are not shown.

  Further, in the conventional positioner positioning method, there are cases where there are a plurality of target angles due to the function of the positioner, or there are cases where the target accurate angle cannot be found. In such a case, the optimum angle is searched and determined. Therefore, there is a problem that the operator has to rely on the experience and feeling of the operator. Furthermore, when the weld line is an arc or free curve on a curved surface, it takes a long time to search for the optimum positioner angle, and it is difficult to evaluate whether the obtained search results are optimal. .

  In addition, when performing actual machine teaching using an actual robot, the operator approaches the work mounted on the positioner, installs an inclinometer at several locations, and guides the positioner to obtain the plate surface angle. Thus, there are various problems in safety, efficiency and accuracy.

  For example, Japanese Patent Application Laid-Open No. 11-347733 is known as a conventional technique relating to such a positioner positioning method or a welding robot automatic teaching method. The purpose of this conventional technique is to automatically calculate the positioner angle so that the welding position of the robot is as downward as possible when creating a welding robot system program that positions the workpiece using the positioner. It was made.

  FIG. 17 is an explanatory diagram for obtaining a release vector from the normal vector of each surface of the welded portion in the above-described prior art. In FIG. 17, a vector VA that divides the angle formed by two normals into two equal parts is obtained from the normal vector V1 of the surface SA and the normal vector V2 of the surface SB at the welding start point PA of the weld line 58. Similarly, a release vector VB (not shown) at the welding end point PB is obtained. Such work is performed on the weld lines of all the joints, and this release vector or angle from one side is designated and used as a welding posture. That is, in the above prior art, after obtaining a weld line from the workpiece shape and welding attribute data input in the designed three-dimensional CAD, the release direction of the torch at the weld line is obtained, and the positioner is set so that the torch is directed downward. (Patent Document 1, paragraph 0030, FIG. 3).

Japanese Patent Laid-Open No. 11-347733

  However, the above prior art uses a vector defining one direction, and has the following problems.

  That is, since the release vector for determining the positioner angle disclosed in the above prior art is a two-dimensional one that is geometrically determined by the design CAD, it is not possible to set a subtle inclination. The prior art has a problem that it is difficult to maintain high welding quality. Also, in actual welding sites, the welding posture is not limited to the downward direction, it is necessary to cope with various welding postures in a short time, and the workpiece may be slightly inclined as necessary to improve the welding quality. It is necessary to accurately adjust this inclination angle, and when the welding line is an arc or a free curve placed on the curved surface, it is necessary to determine the angle of the plate surface on the curved surface, and It is necessary to satisfy various requirements such as the ability to determine an optimal angle so that the robot can smoothly move the point. However, the above-described prior art has a problem that the above-described requirement cannot be satisfied.

The present invention has been made in view of such problems, and in order to determine a welding line when performing automatic welding using a welding robot, positioning of a positioner that supports a workpiece can be safely and accurately performed in a short time. it can be performed, thereby an object to provide a method of setting the positioner for welding robot can be highly stable weld quality.

Setting of the welding robot positioner according to the first aspect of the present process, each inclined position a first axis and a second axis of the positioner as welding target word click installed in the positioner has a desired arrangement in setting of the welding robot positioner to determine an angle theta ₁ and theta _2, the steps of Maseru write read a three-dimensional model of the workpiece with mechanism information of the positioner to the computer, at least an operator of the welding target member of said model a step of instructing one of the one of the weld surface or line on a computer, the steps of determining by calculation the reference line defining the inclination of the welding site from the welding surface or line information is instructed, the reference for the two directions orthogonal to each other as the angle at which the line is tilted from the vertical direction α and beta, the target angle of the α and beta operator to set the computer Process and, by moving the workpiece model to the extent permitted by mechanism of the positioner rotates the reference line, it said α and said β is one of the theta ₁ and theta ₂ to a predetermined range of the target angle the fixed other of theta ₁ or theta ₂ one or more search or a step of determining a theta ₁ and theta combination of one or more sets search and positioner positions of _2, 1 or obtained by searching a combination of a plurality of sets of the theta ₁ and theta theta ₁ an optimal positioner position from the _second combination and theta ₂ and step operators you-option selected,
It is characterized by having.

Setting of the welding robot positioner according to the second aspect of the present process, each inclined position a first axis and a second axis of the positioner as welding target word click installed in the positioner has a desired arrangement in setting of the welding robot positioner to determine an angle theta ₁ and theta _2, the steps of Maseru write read a three-dimensional model of the workpiece with mechanism information of the positioner to the computer, at least an operator of the welding target member of said model a step of instructing one of the one of the weld surface or line on a computer, the steps of determining by calculation the reference line defining the inclination of the welding site from the welding surface or line information is instructed, perpendicular to the plane containing the weld site When the reference line is projected onto a surface, the angle formed by the reference line with respect to the vertical direction is α, and the reference line is projected onto the surface including the welded part. The angle formed the reference line with respect to the vertical direction β when the the steps of the target angle of the α and β operator sets the computer, the workpiece model to the extent permitted by mechanism of the positioner rotating the reference line moving, the α and the β is 1 or more search the other theta ₁ or theta ₂ by fixing one of the theta ₁ and theta ₂ to a predetermined range of the target angle Or a step of obtaining one or a plurality of combinations of θ ₁ and θ ₂ to obtain a positioner position, and an optimal positioner position from the one or a plurality of combinations of θ ₁ and θ ₂ obtained by the retrieval. The operator selecting a combination of θ ₁ and θ ₂ to be

In the method for setting a positioner for a welding robot according to the present invention, the step of designating the welding surface is performed when the operator positions three points on the welding surface on the display screen of the computer when the welding surface is a plane. Click to specify the three-dimensional coordinates (x11, y11, z11), (x12, y12, z12), (x13, y13, z13) of the three points on the welding surface or the display screen, It is preferable that the equation of the surface is obtained from the surface information of the CAD data inputted in advance by clicking one point.

Further, in the method of setting welding robot positioner according to the present invention, the reference line, for example, Ru different by welding position.

Further, in the method of setting welding robot positioner according to the present invention, the reference line, for example when the welding positions is downward welding, Ru line der that between bisected the respective normals of the two welding surfaces .

Further, in the method of setting welding robot positioner according to the present invention, the reference line, for example when the welding positions is horizontal, perpendicular to the welding plane of the line perpendicular or upright side welding surface of the base metal Sendea Ru.

Further, in the method of setting welding robot positioner according to the present invention, for example, if the welding surface is an arc surface, the reference line is a line perpendicular to the tangent at the weld point by a line passing through the arc center Oh Ru.

In setting of the welding robot positioner according to the present invention, when said rotational angle around the gravity vertical plumb line of the work model was gamma, of one or more combinations the α and β becomes equal to the target angular range positioner step of determining position by calculation, the γ yet good also der those for calculating the combinations so that the target angle range in addition to the α and said beta.

In setting of the welding robot positioner according to the present invention, the robot on the computer based on the positioner positions the computer is determined by the calculation based on the operator optimum becomes positioner position theta ₁ and theta ₂ of the selected combination It is preferable to have the process of guide | inducing to a welding surface or a welding line.

Further, in the method of setting welding robot positioner according to the present invention, for example, when the positioner is one having a plurality of rotary shafts, it is preferable to have a step of calculating the fixedly positioner located an axis of rotation.

Further, in the method of setting welding robot positioner according to the present invention, further comprising the step of stored once computer table positioner positions of a plurality of combinations determined by the calculation, is displayed on the screen based on display command Is preferred.

According to the setting method for a welding robot positioner according to the first invention of the present application, the positioning of the positioner that realizes the welding posture in robot welding is performed using a computer, so that it is conventionally difficult to take a long time at a welding site. Positioning work that has been performed can be performed safely and accurately in a short time. Also, without requiring operations easy skill, the computer can be obtained optimal from a plurality of candidates retrieved.

According to method of setting welding robot positioner according to the present second invention, as with the invention, conventionally, the positioning operation of the positioner which has been performed by welding site with a risk over a long period of time short time safely and accurately It can be carried out. Also, without requiring operations easy skill, the computer can be obtained optimal from a plurality of candidates retrieved.

According to method of setting welding robot positioner according to claim 3 of the present application, the coordinates of three arbitrary points on the plane designated reference plane on the workpiece (x, y, z) or previously performed by specifying Since the surface equation is obtained from the surface information of the input CAD data, the plane of the workpiece can be specified accurately and easily. In addition, this makes it possible to perform the positioning operation of the positioner more quickly and accurately. That is, by designating three-dimensional coordinates of three points, surface information is obtained by creating a surface equation from the information of these three points. It is also possible to specify a surface on the work model and obtain surface information from coordinate values included in advance in the work model.

According to method of setting welding robot positioner according to claim 4 of the present application, since the base line was set to differ depending on welding position is not limited to the downward welding, horizontal fillet welding, horizontal welding, welding of the standing facing welding The positioner angle that realizes the posture can be accurately determined in a short time. Further, for the purpose of improving the welding quality, it is possible to carry out accurately and in a short time even when a slight inclination angle is given to the horizontal plane as necessary.

Line addition, according to the method of setting welding robot positioner according to claim 5 of the present application, the reference line when welding positions is downward welding, which between each normal of the two welding surfaces bisect Therefore, positioning of the positioner in downward welding can be performed accurately in a short time.

Further, according to the method of setting welding robot positioner according to claim 6 of the present application, the reference line when welding positions is horizontal, the welding surface of the vertical lines or upright side welding surface of the base metal Since the vertical line is used, positioning of the positioner in horizontal fillet welding can be accurately performed in a short time.

According to method of setting welding robot positioner according to claim 7 of the present application, and a line in which the weld surface passes through the arc center a line perpendicular to the tangent at the welding point reference line when an arc surface Therefore, the positioner can be accurately positioned when the welding surface is an arc.

According to method of setting welding robot positioner according to claim 8 of the present application, when said rotation angle around the vertical line of the work model was gamma, 1 or more combinations the α and β is the target angle range In the step of calculating the positioner position of the position of the positioner, the combination of the position angle of the positioner according to the actual work situation is determined because the combination of the position of the position angle γ is calculated so that the angle γ is within the target angle range. More specifically, it can be performed.

According to method of setting welding robot positioner according to the present claim 9, since it is assumed that a step of inducing the robot on a computer to the welding surface or weld line on the basis of the positioner position obtained by the calculation, actual The positional relationship between the welding robot and the workpiece model can be grasped.

According to method of setting welding robot positioner according to claim 10 of the present application, when the positioner is one having a plurality of rotary shafts, and having a step of calculating the positioner position by fixing one axis of rotation Therefore, the positioner position can be specifically determined even when there are infinite solutions of the positioner rotation axis to be obtained.

Furthermore, according to the method of setting welding robot positioner according to claim 11 of the present application, and stored once computer table positioner positions of a plurality of combinations determined by the calculation, displayed on the screen based on display command Therefore, the optimum positioner angle can be selected again after the search is completed.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 is a block diagram of a positioner setting device applied to setting of the welding robot positioner according to the present embodiment. In the present embodiment, a predetermined quadrangle is provided by cutting out one corner of a planar quadrangular plate 33 of the work model shown in FIG. The inclination angle of the positioner shaft is searched when the joining line that is the outer periphery of the joining surface with the plate-like body 34 is used as the welding line. Although it is not easy to search for the optimum positioner angle in such a work model, the two-axis condition of the positioner that enables automatic welding by the welding robot with the joint line in this work model being horizontal and facing the welding torch is obtained. . Hereinafter, the search for the tilt angle of the positioner shaft may be referred to as calculation of the positioner position.

  In FIG. 1, this apparatus includes a search condition setting unit 1 that sets a search condition related to a positioner posture, a reference plane setting unit 2 that sets a reference plane or a reference line of a work supported by the positioner, and a search condition setting unit 1. The work condition calculation preparing unit 3 for aggregating the search conditions set in step 1, the reference plane or reference line data set by the reference plane setting unit 2 and the data 7 related to the work model of FIG. Referring to the display unit 4 for displaying the posture of the work model, the search range setting unit 5 for setting the search range, and the search range data 8 set by the search range setting unit 5, an appropriate inclination of the positioner shaft It is mainly composed of a search for performing an angle (hereinafter also referred to as a positioner value) search and ranking and a ranking unit 6. Note that the operator selects an optimum positioner value, that is, an optimum inclination angle of the positioner, from the appropriate positioner value candidate group 9 ranked by the search and ranking unit 6.

  After the optimum inclination angle is selected by the operator, the two axes of the positioner can be moved to the selected inclination angle on the screen according to the setting conditions, and the welding robot can be moved according to the setting conditions.

  Examples of the search condition data set by the search condition setting unit 1 include inclination angles α and β and a rotation angle γ with respect to a vertical line of a workpiece forming a weld line.

  FIG. 2A to FIG. 2C are explanatory views showing the inclination angle α of the workpiece forming the weld line. The workpiece inclination angle α varies depending on the welding posture or the shape of the weld surface. 2A is an explanatory view showing the inclination angle α in the downward fillet welding, that is, the welding posture is downward, and FIG. 2B is a case where the welding posture is horizontal and the weld surface shape is flat, that is, horizontal. FIG. 2C is an explanatory view showing the inclination angle α when the welding posture is horizontal and the weld surface shape is an arc.

  In FIG. 2A, when the welding posture is downward, a line 14 that bisects the normals 12a and 13a of the two welding surfaces 12 and 13 serves as a reference line, and the bisector 14 and a vertical line. 11 is an inclination angle α. In FIG. 2B, when the welding posture is horizontal, a line 15 perpendicular to the base metal side welding surface 12 is a reference line, and a line 15 perpendicular to the base metal side welding surface 12 is a vertical line. An angle formed by 11 is defined as an inclination angle α. 2C, when the welding posture is horizontal and the weld surface shape is an arc, the angle formed by the arc surface 16 and the vertical line 11, that is, a line perpendicular to the tangent line at the welding point 16a and the center of the arc. The angle formed by the line 16b passing through the vertical line 11 can be defined as an inclination angle α.

  FIGS. 3A and 3B are explanatory views showing the inclination angle β of the workpiece forming the weld line. The workpiece inclination angle β also varies depending on the welding posture and the weld surface shape. FIG. 3A is an explanatory diagram showing the workpiece inclination angle β in fillet welding, and FIG. 3B shows the workpiece inclination angle β when the welding posture is horizontal and the weld surface shape is an arc. It is explanatory drawing.

  In FIG. 3A, an angle formed by a line 19 perpendicular to the welding line 24 where the base material surface 17 and the standing plate surface 18 intersect with the vertical line 11 is defined as β. As shown in FIG. 3B, a line 22 perpendicular to the tangent line at the welding point 21 of the arc 20 when the welding posture is horizontal and the weld surface shape is an arc, and passes through the center of the arc. An angle formed with the vertical line 11 can be defined as β. 2 and 3, only the plane can be set when the welding posture is horizontal.

  FIG. 4 is an explanatory diagram showing the rotation angle γ of the workpiece. In FIG. 4, the rotation angle of the workpiece 23 with respect to the Z axis when the vertical line 11 is the Z axis is defined as the rotation angle γ of the workpiece.

  In the search condition setting unit 1, only the tilt angles α and β or the tilt angles α and β and the rotation angle γ are input and set as search conditions. When α and β are input as search conditions, the inclination angle of the positioner rotation axis in the positioner posture where α and β are close to the target value is searched. The target values of α and β are normally set to 0 degrees. However, for the purpose of improving the quality of welding, the inclination angle β may be set to 5 degrees, for example. In addition, when performing welding with unequal side leg lengths, α is inclined. The input of only the tilt angles α and β is used when examining the positioner posture in various cases.

On the other hand , when the tilt angles α and β and the rotation angle γ are input, the tilt angle of the positioner rotation shaft in the positioner posture in which α, β, and γ are close to the target values is retrieved. The inclination angles α and β and the rotation angle γ are input as, for example, left and right or front and rear angles of the reference coordinates obtained from the reference plane or reference line, and the rotation angle of the workpiece with respect to the vertical direction. The rotation angle γ is input when the rotation angle of the workpiece that the robot can easily approach is known in advance.

  The search condition setting unit 1 can be set to search for the positioner shaft angle θ1 or θ2 when the first axis or the second axis of the positioner is fixed. When the first axis is selected as the fixed axis, the optimum positioner posture in a state where the first axis of the positioner is fixed is searched. On the other hand, when the second axis is selected as the fixed axis, the optimum positioner posture in a state where the second axis of the positioner is fixed is retrieved. In this case, the operator inputs the angle of the positioner shaft fixed to the personal computer. For example, when the first axis is selected as the fixed axis, the angle θ1 with respect to the vertical line of the first axis is input, and when the second axis is selected as the fixed axis, the inclination angle θ2 with respect to the horizontal plane of the second axis is input. When the fixed axis is not set, the positioner posture in a state where the positioner axis is not fixed, that is, the inclination angles θ1 and θ2 of the first axis and the second axis are searched.

  The search condition setting unit 1 can set whether or not to guide the robot based on the search result. When the setting for guiding the robot is made, the welding robot is guided to the reference position on the personal computer screen with respect to the plate surface or welding line displayed on the screen after the search is completed. The robot is guided with priority on slider guidance, for example. When the operating range limit of the slider is reached, it is supplemented by robot guidance, for example. Note that the posture of the wrist of the robot is determined by, for example, the complement mode. That is, when the wrist mode is held, it is determined depending on, for example, whether the posture of the immediately preceding step is held or whether the wrist angle of the immediately preceding step is held. Further, it is possible to select to fix the positioner at the optimum position based on the search result.

Further, the search condition setting unit 1 can input and set the maximum number of positioner posture searches, for example, 1 to 99. However, for example, if the search result is 30 ° or more away from the target values of α and β, it can be excluded from candidates. Therefore , the number of candidates may be less than the maximum search value. The search condition setting unit 1 further sets a welding posture, for example, whether it is downward welding or horizontal welding.

  Next, in the reference plane setting unit 2 that sets the reference plane or the reference line, for example, in the case of fillet welding, the base plane and the standing plane are instructed to recognize the reference plane. Specifically, the coordinate data of the three points on the base material surface and the standing plate surface are selected by point sequence selection, for example, point a (x1, y1, z1), point b (x2, y2, z2), point c (x3), respectively. , Y3, z3), the base material surface and the standing plate surface are specified, and a line intersecting these two surfaces is selected as a valley of the weld line. In the case of an arc, three vertices of the work model to be a weld line are designated.

  At this time, the selection of the coordinates of the three points is performed, for example, by clicking the three points on the screen with the mouse. Further, when inputting the three points constituting the standing plate surface, it is also possible to specify that the direction connecting the first point and the second point is the welding direction. Furthermore, the point selection mode can be changed to the surface selection mode.

  The reference plane setting unit 2 sets a reference line (vertical line) that becomes the center of rotation when the rotation angle γ of the workpiece is obtained. FIG. 5 is an explanatory diagram showing a reference line for obtaining the rotation angle γ of the workpiece, FIG. 5 (a) is a diagram showing a reference line in the case of horizontal overlay welding, and FIG. 5 (b) is a horizontal fillet welding. FIG. 5 (c) is an explanatory diagram showing a reference line for downward fillet welding, and FIG. 5 (d) is a case where the welding posture is horizontal and the welding surface shape is an arc. It is explanatory drawing which shows a reference line.

  5A, in the case of horizontal build-up welding, the line is perpendicular to the designated surface (weld surface) 41 and crosses the weld surface 41 at a point 43 at one corner of the weld surface 41, for example. The line 42 to be used is set as a reference line for obtaining the rotation angle γ. Therefore, the rotation angle of the work rotated about the reference line 42 as the rotation axis becomes the rotation angle γ. The reference line for defining the angles α and β may be a line perpendicular to the surface 41, but when defining the rotation angle γ, for example, a line that passes through the point 43 among the lines perpendicular to the surface 41 is used. Must be defined as a book line.

  In the case of horizontal fillet welding, as shown in FIG. 5 (b), since there is a standing plate 44 on the indicated welding surface 54 on the base material side, for example, this standing plate 44 and the welding surface on the base material side are provided. A line 46 perpendicular to the base metal side weld surface 54 at the end point 47 of the weld line 45 to the base line 54 is set as a reference line for obtaining the rotation angle γ. Therefore, the rotation angle of the workpiece rotated about the reference line 46 as the rotation axis is the rotation angle γ.

  In the case of downward fillet welding, as shown in FIG. 5C, for example, the normal lines 36a of the two welding surfaces 36 and 37 at the end points 49 of the welding line 48 where the welding surfaces 36 and 37 contact each other. , 37a is set as a reference line for obtaining the rotation angle γ. Accordingly, the rotation angle of the work rotated about the reference line 38 as the rotation axis becomes the rotation angle γ.

  Further, when the welding surface is an arc, as shown in FIG. 5D, for example, a rotation angle γ is obtained for a line 53 that is perpendicular to the tangent line 52 at the welding point 51 and passes through the center O of the arc. Set as the reference line. Therefore, the rotation angle of the workpiece rotated around the reference line 53 becomes the rotation angle γ.

  In addition, when the surface to be the reference surface of the workpiece is an arc surface, each arc surface can be approximated to a plane by subdividing the arc surface, and can be assumed to be a plane. Coordinate data can also be specified in the same manner as the setting of the base material surface or the standing plate surface.

  In the workpiece posture calculation preparation unit 3, the conditions set by the search condition setting unit 1, the reference plane data set by the reference plane setting unit 2, and the workpiece model data 7 shown in FIG. .

  The posture display unit 4 displays the workpiece posture and the vertical direction, and the search and ranking unit 6 searches for a specific appropriate positioner value, that is, the search for the tilt angle of the rotation axis of the positioner that supports the workpiece and the rank of the search results. The attachment is done. At this time, the search range data 8 of the positioner value set by the search range setting unit 5 is referred to. As an example of setting the search range, a case where the rotation angle of the positioner is limited to 180 degrees, for example, can be considered. This is because the rotation shaft of the positioner cannot always rotate 360 degrees, and the rotation angle is limited based on the workpiece shape and the like.

  The search result is displayed on the computer screen as a group of appropriate positioner value candidates, and the optimum positioner value is selected by the operator.

Hereinafter, a positioner setting method as an operation of the positioner setting device applied to the present embodiment having such a configuration will be described. Figure 7 is a flow chart of a method of setting a welding robot positioner according to the present embodiment. In FIG. 7, a trapezoidal portion indicates input by an operator, a rectangular portion indicates processing by a computer, and a parallelogram portion indicates data.

  Before starting the positioning work of the positioner, the operator first causes the computer (hereinafter referred to as a personal computer) in which a CAD system is stored to read the work model together with the model of the 2-axis positioner (step 1). FIG. 6 is an explanatory diagram showing the relationship between the work model 30 captured on the computer and the two axes of the positioner that supports it. In FIG. 6, this positioner has two axes of a first axis 31 and a second axis 32, and the welding line of the work model 30 is a plane that is in contact with a flat rectangular plate 33 and one surface of the plate 33. It is the outer periphery of the joint surface with the plate-like body 34 provided with a predetermined radius by cutting out one corner of the triangle, and consists of a straight line portion and a curved portion. The straight portions of the weld lines between the plate-like bodies 33 and 34 are inclined with respect to the first shaft 31 and the second shaft 32, and the first shaft 31 and the second shaft where the straight portions of the weld lines become horizontal thereafter. 32 inclination angles (θ1, θ2) are obtained.

  After the work model 30 has been read into the personal computer, the operator sets search conditions. That is, it is selected whether the welding posture on the weld plate surface is “downward” or “horizontal”. FIG. 8 is a diagram showing a personal computer screen when setting a search condition. The operator selects, for example, the welding posture “horizontal” in the uppermost welding posture setting unit in FIG. 8 (step 2).

  At this time, it is determined whether or not “downward” is selected as the welding posture by the personal computer (step 3). If “downward” is not selected as in the present embodiment, the shape of the welding surface is “ It asks if it is a “plane” or “arc”. Accordingly, the operator selects that the welding surface (surface B) is “planar” on the screen shown in FIG. 8 (step 4).

  At this time, it is determined whether or not “plane” is selected as the welding surface by the personal computer (step 5). In the present embodiment, since “plane” is selected, the process proceeds to step 7. In Step 7, since the welding posture “horizontal” is set in Step 2 in this embodiment, the operator needs to select and specify the surface B of the work model 30 as the base material surface on the screen (Step 7). ).

  FIG. 9 is a diagram showing a personal computer screen for setting the number of point sequences in the point sequence selection. The operator inputs, for example, the number of point sequences 3 on the personal computer screen of FIG. 9 and clicks, for example, three points on the surface B of the work 30 on the screen to thereby generate points a (x1, y1, z1) and b (x2). , Y2, z2) and the point c (x3, y3, z3) are input to specify the surface B. At this time, by clicking one point on the surface B, the surface equation can be obtained from the surface information of CAD data inputted in advance, and the surface B can be specified by this.

  When the surface B is specified, the coordinates of a line perpendicular to the base material surface in the surface B are automatically determined based on the surface information of the surface B according to a program input in advance.

  In Step 2, when the welding posture is “downward”, it is necessary to select the base material surface and the standing plate surface on the screen (Step 7). The reference plane is selected by designating the coordinates of three points as described above.

  On the other hand, if “plane” is not selected in step 4, the personal computer asks for the data of the arc that is the welding surface. Accordingly, for example, the operator designates the three-point coordinate data of each virtual plane constituting the arcuate surface segmented as described above (step 6).

  After step 7 is completed, the personal computer sets surface B as a reference surface to be used as a reference for welding, displays the vertical direction, and the angle of inclination α, β and rotation angle of the current welded plate surface between surface B and surface A γ is displayed (step 8).

  Here, as described above, the inclination angle α of the welding surface varies depending on the welding posture, but the welding between the surface B and the surface A in the workpiece model 30 is regarded as horizontal fillet welding, and the surface B as the base material surface is obtained. An angle formed by a vertical line (normal line) and a vertical line is used as the inclination angle α.

  On the other hand, the inclination angle β of the welding surface also varies depending on the welding posture, but since the welding between the surface B and the surface A in the workpiece model 30 in FIG. 6 is fillet welding, an angle formed by a line perpendicular to the welding line becomes a vertical line. Is used as the inclination angle β.

  As the rotation angle γ of the welding surface, the rotation angle on the horizontal plane with respect to the vertical line at one point on the intersection line between the surface B and the surface A of the workpiece model 30 is used.

  After the inclination angles α and β and the rotation angle γ of the surface B and the surface A in the current work model 30 are displayed on the personal computer screen (step 8), the operator is based on the search condition setting screen of FIG. The set values α, β, and γ of the tilt or rotation angle are all set and changed to, for example, 0.00 degrees (step 9).

  When the tilt or rotation angles α, β, γ are changed, the personal computer changes the posture of the work model 30 on the screen in accordance with the changed tilt angle (step 10).

  Next, the operator uses all of the inclination or rotation angles α, β, γ of the welding surface as search conditions for the positioner angle while referring to the condition setting screen of FIG. 8, or uses only the inclination angles α, β. Decide what to do. When α, β, and γ are selected, a positioner posture in which α, β, and γ are close to target values is searched. On the other hand, when α and β are selected, a positioner posture in which only α and β are close to the target value is searched. The input of only α and β is used when examining the positioner posture in various cases. Here, all of α, β, and γ are selected.

  When the weld line is parallel to the rotation axis of the positioner, there may be countless solutions that satisfy α and β. Therefore, a search is performed with one of the rotation shafts of the positioner fixed as follows. That is, the operator can select the fixed axis of the positioner while referring to the condition setting screen of FIG. When the first axis of the positioner is selected as the fixed axis, the positioner posture in a state where the first axis of the positioner is fixed is retrieved. On the other hand, when the second axis of the positioner is selected as the fixed axis, the positioner posture in a state where the second axis of the positioner is fixed is retrieved. When the rotation axis is selected, the operator inputs the value of the inclination angle of the fixed axis of the selected positioner. For example, when the first axis is selected as the fixed axis, the angle θ1 with respect to the vertical line of the first axis is input, and when the second axis is selected as the fixed axis, the inclination angle θ2 with respect to the horizontal plane of the second axis is input. When neither the first axis nor the second axis is selected as the fixed axis, it is selected that the positioner axis is not fixed. Here, no fixed axis is set.

  At this time, the operator can select in advance whether or not to guide the welding robot to the positioner position selected and determined based on the search result while referring to the condition setting screen of FIG. If guidance is selected, the robot is guided to the reference position after the search is completed. On the other hand, if it is selected not to guide, the robot is not guided. Here, set to guide the robot. Further, at this time, the operator can set the maximum number of searches while referring to the condition setting screen of FIG. Here, a maximum search number of 10 is set. (Step 11).

  When the search conditions for the positioner positioning search are set in this way, the personal computer moves the positioner shaft operating ranges θ1 and θ2, whether the positioner shaft is fixed, whether the fixed shaft is one or two axes, etc. Based on the above, the search range of the positioner shaft inclination angle when the welding line formed by the surface B and the surface A of the workpiece model 30 is robot-welded is obtained (step 12).

Next, the personal computer sets the inclination angle of the positioner shaft to an arbitrary value within the search range (step 13), and changes the posture of the positioner and the workpiece based on this value (step 14).

  Next, the personal computer calculates the inclination or rotation angle α, β, γ of the welding surface in the changed workpiece posture and the preset inclination or rotation angle α, β, γ of the welding surface (all 0.00 degrees). And the errors of Δα, Δβ, Δγ for each positioner angle are stored in a table (step 15). The error data of Δα, Δβ, and Δγ stored in the table is displayed together with the detection result on a screen (see FIG. 9 described later) that displays the detection result.

Next, it is determined whether or not a search end condition specified in advance, for example, based on the number of calculations, is satisfied (step 16). If the search end condition is not satisfied, the positioner operating ranges θ1 and θ2 are determined. change the (step 17), steps 13 through 16 is repeated back to step 13 described above.

  If the search end condition is satisfied, it is determined whether or not the inclination angles α and β and the rotation angle γ are selected as the search conditions (step 18). In the present embodiment, since the inclination angles α and β and the rotation angle γ are selected, the numerical values of θ1 and θ2 and the posture of the work with a small error in total of α, β, and γ are displayed on the screen (step 19). .

  If only the inclination angles α and β are selected, the numerical values of θ1 and θ2 and the posture of the work with small errors only by α and β and the posture of the work are displayed in order on the screen (step 20).

  FIG. 10 is an explanatory diagram showing a personal computer screen that displays search results. In FIG. 10, ten search results are stored in a table, and the first search result is displayed. The operator looks at the display on the screen in an interactive manner and displays the next search result stored in the table to determine the positioner shaft angles θ1 and θ2 that are most suitable for welding between the surface B and the surface A in an appropriate workpiece. Select and determine (step 21).

  When an appropriate positioner angle is selected by the operator, the personal computer moves the positioner and the workpiece to the selected angle position on the screen (step 22).

  Next, the personal computer determines whether or not a designation for guiding the robot is made in advance based on the search result (step 23).

  In the present embodiment, since the robot has been designated to be guided, the robot on the personal computer is guided to the welding surface or welding line selected on the screen (step 24), and the positioner positioning search is terminated. If no designation for guiding the robot is made, the positioner positioning search is terminated without guiding the robot.

  In this way, the optimum positioner shaft angle in horizontal fillet welding between the surface B and the surface A in the workpiece model 30 is determined. Thereafter, the inclination angle of the positioner when welding the portions other than the surface B and the surface A in the workpiece model 30 is sequentially searched.

  When the surface to be the reference surface of the workpiece is an arc surface, each arc surface is approximated to a flat surface by subdividing the arc surface, and then the tilt angle of the positioner is adjusted by performing the same operation. You can search.

  The search result is transmitted to, for example, a control computer of a welding robot that is an actual machine, and used for actual welding work. FIG. 15 is an apparatus system diagram showing the robot welding apparatus. In FIG. 15, a work 64 is supported by a positioner 65, and a welding robot 63 for welding a weld line of the work 64 is disposed. The welding robot 63 is connected to a robot controller device 61 as a control computer by communication means, and the welding robot 63 is controlled by the robot controller device 61. A personal computer 60 as a positioner setting device is connected to the robot controller device 61 by a communication cable 62, for example.

  The search result of the positioner inclination angle obtained by the personal computer 60 as the positioner setting device is sent to the robot controller device 61 via the communication cable 62. After the inclination angle of the positioner 65 is adjusted based on this search result, the welding robot The workpiece 64 is welded by 63.

  According to the present embodiment, the positioner angle that realizes a welding posture in horizontal fillet welding, lateral welding, vertical welding, and the like is not limited to downward welding, and can be determined safely and accurately in a short time. In addition, by adopting a general-purpose offline teaching system that can register various robot systems, not only the positioner mechanism but also the positioner angle that realizes the welding posture can be determined safely and accurately in a short time. it can. Therefore, by performing actual welding with the positioner angle determined by this method, a stable product with high welding quality can be obtained.

  In the present embodiment, there are no obstacles for the robot to access other than the positioner angle as the standard for the operator to select the optimal one from the candidates shown as the PC search results, and the shortest For example, whether the route is connected or not.

  In the present embodiment, the optimum positioner angle in the horizontal fillet welding of the surface A and the surface B in the work model 30 shown in FIG. 6 is determined by offline teaching using a personal computer. By providing the means, it can be used in an actual robot system.

  Here, a method for creating a teaching program using the offline teaching apparatus as the basis of the present invention will be described.

  Off-line teaching is a teaching program for workpieces to be welded by displaying peripheral devices such as workpieces, robots, positioners, etc. in the virtual space of the computer, and the operator guiding the virtual robots through a personal computer input device such as a mouse or keyboard. It can be called virtual teaching performed on a computer.

FIG. 16 is a flowchart showing a method for creating a teaching program using the offline teaching apparatus. In FIG. 16, a teaching program is created by the following procedure.
(1) First, a part model to be a part of the work model is created. The part model is created, for example, by selecting the shape of a figure using a button displayed on a personal computer screen and then inputting the dimensions. In order to create a part model, there is a 2D input method in which a cross-sectional shape is input and a plate thickness is input in addition to such a method of entering dimensions.
(2) Next, a work model is created.

A work model is created by moving the created part models and combining them like building blocks. After the combination, in order to indicate that each part of the work model is an integral part, parent-child designation is performed with the parent material as the parent and each member as the child. This is a work equivalent to temporary attachment at an actual work site.
(3) Next, the work model is arranged.

The work model is placed on the robot system in the virtual space as in the actual system. After the placement, it is instructed through the screen that the work model is attached to the positioner.
(4) Next, a teaching program is created.

  That is, teaching work on an actual line is realized in a virtual space on a computer. In teaching in the virtual space, first, the position angle is entered numerically on the screen to determine the workpiece posture. Next, in order to guide the robot, the robot tip position XYZ is designated by a number, for example. Then, the robot position is changed according to the number. When the robot arrives at a position to be moved in the virtual space, the position is stored by issuing a position determination instruction from the keyboard. By repeating such operations, a teaching program is created in the virtual space.

In the teaching, it is possible to input all control commands that need to be input by actual teaching such as arc ON in addition to the operation of creating the robot trajectory in the virtual space.
(5) Next, simulation (reproduction) is performed.

The validity of the teaching program created by simulation in the virtual space is confirmed.
The following are examples of simulation functions.

  (A) An interference check between the robot and the workpiece is performed. That is, when the teaching program is created so as to pass an illegal route, or when a narrow part where the torch interferes is forcibly taught, the interference part is displayed in red during the simulation, and a warning is prompted.

  (B) An instruction error check is performed. That is, a warning is issued when an instruction is inserted at an illegal position in the teaching program, or when an illegal combination of instructions is set.

  (C) An operating range check is performed. That is, it is possible to confirm in advance whether or not the limit of each axis of the robot is exceeded by the teaching program created by simulation and whether or not the robot enters a singular point.

In this case, by using the software of the actual robot as it is in the simulation, a highly accurate simulation becomes possible, and the checks of (a), (b), and (c) become more accurate.
(6) Save the program.

  Since the results of the above checks (a), (b), and (c) can be left as a record, it is possible to correct the defective part collectively after the simulation is finished.

  Thus, according to the off-line teaching, it is possible to create a teaching program while saving work and ensuring safety. Therefore, off-line teaching is an effective teaching means similar to or in place of actual machine teaching.

Setting the welding robot positioner of the present invention which can be positioned positioner supporting the workpiece when performing automatic welding using a welding robot short time safely and accurately interactively using a computer welding This is particularly useful in the field of automatic welding using robots.

Is a block diagram of an apparatus for applying the method of setting welding robot positioner according to an embodiment of the present invention. It is explanatory drawing which shows the inclination angle (alpha) of a welding surface. It is explanatory drawing which shows the inclination angle (beta) of a welding surface. It is explanatory drawing which shows the rotation angle (gamma) of a welding surface. It is explanatory drawing of the reference line at the time of calculating | requiring the rotation angle (gamma) of a workpiece | work. It is a figure which shows the positional relationship of the weld line of a work model, and a positioner axis | shaft. It is a figure which shows the flow of the setting method of the positioner for welding robots which concerns on embodiment of this invention. It is a figure which shows the personal computer screen at the time of search condition setting. It is a figure which shows another personal computer screen at the time of search condition setting. It is a figure which shows the personal computer screen which displays a search result. It is a figure which shows the board surface of horizontal fillet welding. It is a figure which shows the board surface of downward fillet welding. It is a perspective view of a real work. FIG. 14 is a front view of FIG. 13. It is an apparatus system diagram showing a robot welding apparatus. It is a figure which shows the flow of offline teaching. It is explanatory drawing which shows a prior art.

Explanation of symbols

1: Search condition setting unit 2: Reference plane setting unit 3: Work posture calculation preparation unit 4: Posture display unit 5: Search range setting unit 6: Search and ranking unit 7: Work model data 8: Search range data 9: Positioner Value candidate group 11: vertical line 12: base metal side welding surface 12a: normal line 13: vertical plate side welding surface 13a: normal line 14: bisector (reference line)
15: Line perpendicular to the base material surface (reference line)
16: Arc surface 16a: Welding point 16b: Line perpendicular to tangent line at welding point 16a 17: Base material surface 18: Standing plate surface 19: Line perpendicular to joining line 20: Arc 21: Welding point 22: Extension of arc radius Line 23: Workpiece 24: Welding line 30: Workpiece model 31: Positioner first axis 32: Positioner second axis 33: Plate body 34: Plate body 36: Weld surface 36a: Normal line 37: Weld surface 37a: Normal 38: Reference line for obtaining the rotation angle γ 41: Welding surface 42: Reference line for obtaining the rotation angle γ 43: Point 44: Standing plate 45: Welding line 46: Reference line for obtaining the rotation angle γ 47: end point 48: welding line 49: point 50: arc 51: welding point 52: tangent line 53: reference line 54 for obtaining the rotation angle γ: welding surface 55: base metal surface 56: standing plate surface 58: welding line 60 : Positioner setting device (PC)
61: Robot controller 62: Communication cable 63: Welding robot 64: Work 65: Positioner

Claims (11)

Setting positioner for welding robot for welding target word click installed in the positioner determines the position of the positioner to the desired arrangement in that the first and second axes of respective inclination angles theta ₁ and theta ₂ In the method
A write Maseru step reads a three-dimensional model of the workpiece with mechanism information of the positioner to the computer,
An operator instructing a computer of at least one welding surface or line of a welding target member of the model;
From the indicated weld surface or line information comprising the steps of determining by calculation the reference line defining the inclination of the welding site,
The angle at which the reference line is inclined from the vertical direction in two directions orthogonal to each other is α and β , and the operator sets the target angles of α and β in the computer ;
Rotating the reference line moving the workpiece model to the extent permitted by mechanism of the positioner, the α and the β are fixed to one of the theta ₁ and theta ₂ to a predetermined range of the target angle Searching for one or more of the other θ ₁ or θ ₂ or searching for one or more combinations of θ ₁ and θ ₂ to determine the positioner position;
1 or more sets of the an optimal positioner positions the combination of theta ₁ and theta ₂ theta ₁ and theta ₂ of the combinations and steps operators you-option selection obtained Locate and
A method for setting a positioner for a welding robot. Setting positioner for welding robot for welding target word click installed in the positioner determines the position of the positioner to the desired arrangement in that the first and second axes of respective inclination angles theta ₁ and theta ₂ In the method
A write Maseru step reads a three-dimensional model of the workpiece with mechanism information of the positioner to the computer,
An operator instructing a computer of at least one welding surface or line of a welding target member of the model;
From the indicated weld surface or line information comprising the steps of determining by calculation the reference line defining the inclination of the welding site,
The angle formed by the reference line with respect to the vertical direction when the reference line is projected onto a surface orthogonal to the surface including the welded part is α, and the reference is projected when the reference line is projected onto the surface including the welded part. The angle that the line makes with the vertical direction is β, and the operator sets the target angles of α and β in the computer ;
Rotating the reference line moving the workpiece model to the extent permitted by mechanism of the positioner, the α and the β are fixed to one of the theta ₁ and theta ₂ to a predetermined range of the target angle Searching for one or more of the other θ ₁ or θ ₂ or searching for one or more combinations of θ ₁ and θ ₂ to determine the positioner position;
An operator selecting a combination of θ ₁ and θ _{2 that is} an optimal positioner position from one or a plurality of combinations of θ ₁ and θ ₂ obtained by searching;
A method for setting a positioner for a welding robot. In the step of indicating the welding surface, when the welding surface is a flat surface, the operator clicks three positions on the welding surface on the display screen of the computer, and three points on the welding surface are displayed. Dimension coordinates (x11, y11, z11), (x12, y12, z12), (x13, y13, z13) are specified or clicked on a point on the welding surface on the display screen and entered in advance The method for setting a positioner for a welding robot according to claim 1 or 2, wherein a surface equation is obtained from surface information of CAD data. The method for setting a positioner for a welding robot according to any one of claims 1 to 3, wherein the reference line differs depending on a welding posture. The setting of the positioner for a welding robot according to claim 4, wherein the reference line is a line obtained by equally dividing a normal between two welding surfaces when the welding posture is downward welding. Method. 5. The welding robot according to claim 4, wherein the reference line is a line perpendicular to a welding surface on a base metal side or a line perpendicular to a welding surface on a standing plate side when a welding posture is horizontal. How to set the positioner. 5. The positioner for a welding robot according to claim 4, wherein when the welding surface is an arc surface, the reference line is a line that is perpendicular to a tangent at a welding point and passes through the center of the arc. Setting method. When the rotation angle around the vertical line of the workpiece model is γ, the step of calculating the positioner position of one or a plurality of combinations in which α and β are within the target angle range is calculated in addition to α and β The method for setting a positioner for a welding robot according to claim 1, wherein the combination is calculated so that γ also falls within a target angle range. Any of claims 1 to 8 computers based on operator optimum becomes positioner position theta ₁ and theta ₂ of the selected combination is characterized by having a step of inducing the robot on a computer to the welding surface or weld line A method for setting the positioner for a welding robot according to claim 1. 10. The welding robot according to claim 1, further comprising a step of calculating a positioner position while fixing one rotation shaft when the positioner has a plurality of rotation shafts. 11. How to set the positioner. 11. The method according to claim 1, further comprising a step of temporarily storing a plurality of combinations of positioner positions obtained by the calculation in a table of a computer and displaying the positions on a screen based on a display command. The setting method of the positioner for welding robots of description.

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