JP5199573B2 - Welding robot attitude determination method - Google Patents

Description

  The present invention relates to a welding robot posture determination method.

  Conventionally, for example, in a welding process of an automobile production line, a plurality of welding robots equipped with a welding gun are used. Each of the plurality of welding robots welds a welding work, which is a welding target, with a plurality of preset welding points using a welding gun.

  By the way, in order to perform such a welding process, it is necessary to assign thousands of welding points of automobiles to each welding robot. Here, in order to reliably weld the welded workpiece, a welding gun is applied to the welded workpiece at each welding point, taking into account the interference between the welding robot and the welded workpiece and between the welding robot and the surrounding structure. It is necessary to assign each welding spot to each welding robot so as to be as vertical as possible. For this reason, in this assignment work, it was necessary to rely on human hands, and the study work took time.

In order to solve this problem, a method of automatically determining the attitude of the welding robot has been proposed (see, for example, Patent Document 1). In the method disclosed in Patent Document 1, first, a weldable angle region in which the welding gun can be welded without interfering with the welding workpiece or surrounding structures, among the attitudes of the welding gun with respect to the welding workpiece, for each welding point by the computer. To decide. Next, the attitude of the welding robot is determined so that the welding gun is disposed at the center position of the determined weldable angle region. According to this method, since the attitude of the welding robot can be automatically determined, it is possible to reduce the time required for the work for examining the assignment of welding points.
JP 2002-239957 A

  By the way, in the method shown in patent document 1, since the attitude | position of the welding gun arrange | positioned in the center position of the weldable angle area | region is uniformly determined for every welding point as the optimal attitude | position of a welding gun, each welding Although it is optimal for the hit point, it may not be optimal for a series of operations of the welding robot in the welding process. In other words, when welding a plurality of welding points in succession with the welding robot, the posture of the welding robot may be greatly changed, which increases the wasteful movement of the welding robot and reduces the cycle time of the welding process. It may become long. Therefore, it is difficult to use the attitude of the welding robot determined by the method disclosed in Patent Document 1 for off-line teaching as it is, and manual fine adjustment work may be necessary.

  An object of this invention is to provide the attitude | position determination method of the welding robot which can reduce the useless operation | movement of a welding robot.

  The welding robot posture determination method according to the present invention is a welding robot posture determination method including a welding gun for welding at a plurality of welding points set on a welding workpiece, wherein the welding gun includes the welding gun for the welding points. The range of postures that the welding gun can take when welding is possible without interfering with the workpiece and surrounding structures is determined as a weldable range, and a position at which the weldable range is divided into a plurality of positions is extracted as a divided position For each of the divided positions, a second step for extracting a posture that can be taken by the welding robot in accordance with a posture of the welding gun as a welding robot possible posture, and an order for welding the plurality of welding points. When the welding stroke order is determined and welding is performed according to the welding stroke order, the change in the position of the welding gun before and after the welding stroke order is reduced. As such, the respective welding spots, characterized in that it comprises a third step for selecting one of the divided position.

According to the present invention, a plurality of division positions are extracted for each welding hit point, and a welding robot possible posture is extracted for each of these division positions. Then, one of the divided positions is selected for each welding hit point so that the change in the attitude of the welding gun before and after the welding hit order becomes small.
That is, instead of uniformly determining the position of the welding gun disposed at the center position of the weldable angle region as the optimum position of the welding gun as in the prior art, the weldable range is divided at a plurality of divided positions. The posture of the welding gun and the posture of the welding robot are determined using this division position. For this reason, even if the weldable range angle is large, it is possible to reduce the change in the position of the welding gun and the position of the welding robot when welding at multiple welding points according to the welding stroke order. Can be reduced. Therefore, since the welding robot can be operated smoothly and the cycle time of the welding process can be shortened, the position of the welding robot determined according to the present invention can be used for off-line teaching as it is, and the man-hours for manual fine adjustment work can be greatly reduced. it can.

  The welding robot posture determination method according to the present invention is a welding robot posture determination method including a welding gun for welding at a plurality of welding points set on a welding workpiece, wherein the welding gun includes the welding gun for the welding points. The range of postures that the welding gun can take when welding is possible without interfering with the workpiece and surrounding structures is determined as a weldable range, and a position at which the weldable range is divided into a plurality of positions is extracted as a divided position. For each of the divided positions, a second step for extracting, as a welding robot possible posture, a posture that the welding robot can take according to the posture of the welding gun, and a basic posture of the welding robot. The welding robot basic posture is determined, and the change in posture from the welding robot basic posture to the welding robot possible posture is small. In order, in order to determine the priority order of the welding robot possible posture, the order of welding the plurality of welding points is determined as a welding striking order, and when welding is performed according to the welding striking order, before and after the welding striking order. A fourth step of selecting one of the divided positions for each welding point so that the change in the attitude of the welding gun is small and the priority determined in the third step is high. And.

According to the present invention, a plurality of division positions are extracted for each welding hit point, and a welding robot possible posture is extracted for each of these division positions. In addition, the priority order of the welding robot possible postures is determined in ascending order of the posture change from the welding robot basic posture to the welding robot possible posture. Then, one of the divided positions is selected for each welding hit point so that the change in the attitude of the welding gun before and after the welding hit order becomes small and the priority order becomes high.
Therefore, even if there are a plurality of welding robot possible postures for one welding hit point, one welding robot possible posture can be extracted for one welding hit point by using the priority order of the welding robot possible postures.

  In this case, in the first step, when there are a plurality of weldable ranges for each welding point, for each of the plurality of weldable ranges, a position that divides the weldable range into a plurality is extracted as a division position. Is preferred.

According to the present invention, in the first step, when there are a plurality of weldable ranges for each welding point, a position at which the weldable range is divided into a plurality of weldable ranges is extracted as a divided position.
Therefore, even when there are a plurality of weldable ranges at one welding point, the division positions can be extracted from all the weldable ranges, so that the optimum posture for the welding gun and the welding robot can be reliably selected.

  According to the present invention, instead of uniformly determining the position of the welding gun arranged at the center position of the weldable angle region as the optimum position of the welding gun as in the prior art, the weldable range is divided into a plurality of divided positions. The position of the welding gun and the position of the welding robot are determined using the divided positions. For this reason, even if the weldable range angle is large, it is possible to reduce the change in the position of the welding gun and the position of the welding robot when welding at multiple welding points according to the welding stroke order. Can be reduced. Therefore, since the welding robot can be operated smoothly and the cycle time of the welding process can be shortened, the position of the welding robot determined according to the present invention can be used for off-line teaching as it is, and the man-hours for manual fine adjustment work can be greatly reduced. it can.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of a welding robot 10 according to an embodiment of the present invention.

The welding robot 10 has so-called six axes, and includes a welding gun 18, arms 12, 13, 14, 15, 16, 17 that change the orientation of the welding gun 18 and the position in a three-dimensional space, and these arms 12. ˜17, a welding robot body 11 is provided.
The welding robot 10 operates according to a control signal transmitted from the control device 20.

  The control device 20 transmits a control signal to the welding robot 10 in accordance with the welding robot posture determined by the welding robot posture determination device 30 (see FIG. 2).

The welding gun 18 is a so-called X-type welding gun, and includes a pair of gun arms 182 and 183, a rotation shaft 181 that pivotally supports the pair of gun arms 182 and 183, and a pair of gun arms 182 and 183. An actuator to be driven (not shown).
The rotation shaft 181 is provided on the base end side of the gun arm 182 and the gun arm 183.
In addition, a pair of welding electrodes 184 and 185 extending in a direction substantially orthogonal to the direction in which the rotating shaft 181 extends are provided facing the distal ends of the gun arm 182 and the gun arm 183.
In the welding gun 18, each of the gun arms 182 and 183 rotates about the rotation shaft 181 by the driving force from the actuator, and the distal end of the gun arm 182 and the distal end of the gun arm 183 open and close.

The above welding robot 10 operates as follows.
That is, according to a control signal transmitted from the control device 20, the arms 12 to 17 are respectively driven to change the orientation of the welding gun 18 and the position in the three-dimensional space, that is, the attitude of the welding gun 18. Further, the welding gun 18 is driven in accordance with a control signal transmitted from the control device 20 to open and close the tip of the gun arm 182 and the tip of the gun arm 183.
As described above, as shown in FIG. 1, the welding electrode 184 is applied to the surface of the welding workpiece 200 substantially vertically at the welding point OO, and the welding electrode 185 is applied to the surface of the welding workpiece 300 substantially perpendicularly. , 300 can be sandwiched. In this state, the welding workpiece 200 and the welding workpiece 300 can be welded at the welding spot OO by applying a voltage to each of the pair of welding electrodes 184 and 185 and causing a current to flow through the welding workpieces 200 and 300.

FIG. 2 is a block diagram illustrating a schematic configuration of the welding robot attitude determination device 30. Welding robot posture determination device 30 includes divided position extraction means 31, welding robot possible posture extraction means 32, welding robot basic posture determination means 33, priority order determination means 34, welding striking order determination means 35, welding gun optimum posture determination means 36, And a welding robot optimum posture determining means 37.
The welding robot attitude determination device 30 constructs virtual models of the welding robot 10, welding workpiece, and peripheral structures, and determines the attitude of the welding robot 10 using these virtual models. Based on the determined attitude of the welding robot 10, teaching data for performing offline teaching is generated and transmitted to the control device 20.

  The division position extracting means 31 determines a range of postures that can be taken by the welding gun 18 when the welding gun 18 can be welded without interfering with the welding workpiece and surrounding structures, as a welding possible range. A position where the weldable range is divided into a plurality of positions is extracted as a divided position. Here, it is assumed that the weldable range is divided into three at equal angles at the division position.

  For example, with respect to the welding hit point OO shown in FIG. 1, the division position is examined with reference to FIG.

In FIG. 3, the approach direction of all the welding guns 18 with respect to the welding hit point OO is represented by a circle O centering on the weld hit point OO. Here, the approach direction of the welding gun 18 is a direction from the center of the circle O toward the circumference.
This circle O is divided into two regions, an unreachable range O4 and a reachable range O3.

The unreachable range O4 is a range of the posture of the welding gun 18 when the welding gun 18 cannot reach the welding point OO. This means that the welding gun 18 cannot reach the welding hit point OO in any direction as long as the welding gun 18 enters from the center of the circle O toward the arc of the unreachable range O4. .
That is, in the unreachable range O4, the welding gun 18 is caused by a structural problem of the welding robot 10 or the arms 12 to 17 and the welding gun 18 of the welding robot 10 interfere with the welding workpieces 200 and 300 and surrounding structures. Cannot reach the welding point OO.

  The reachable range O3 is a range of the posture of the welding gun 18 when the welding gun 18 can reach the welding point OO. This means that the welding gun 18 can reach the welding hit point OO in any direction as long as the welding gun 18 enters from the center of the circle O toward the arc of the reachable range O3.

This reachable range O3 includes a weldable range O1.
The weldable range O1 is a range of postures that the welding gun 18 can take when the arms 12 to 17 of the welding robot 10 and the welding gun 18 can be welded without interfering with the welding workpieces 200 and 300 and surrounding structures. is there. This is because the welding gun 18 does not interfere with the welding workpieces 200 and 300 and surrounding structures in any direction as long as the welding gun 18 enters from the center of the circle O toward the arc of the weldable range O1. This means that the welding hit point OO can be reached.
This weldable range O1 is divided into three at equal angles by dividing positions GO1 to GO4.

  Therefore, in the remaining area excluding the weldable range O1 in the reachable range O3, although the welding gun 18 can reach the welding point OO, the arms 12 to 17 of the welding robot 10 and the welding gun 18 are welded workpieces 200 and 300. Or an area that interferes with surrounding structures.

  Returning to FIG. 2, the welding robot possible posture extracting means 32 extracts a plurality of postures that can be taken by the welding robot 10 according to the postures of the welding gun 18 at the divided positions for each welding point as welding robot possible postures, The postures of the arms 12 to 17 of the welding robot 10 when the welding robot 10 takes each welding robot possible posture are calculated.

Welding robot basic position determining means 33, and determines the underlying position of the welding robot 10 as a welding robot basic position, welding in the case where the robot 10 took welding robot basic position, the arms 12 to 17 of the welding robot 10 Are calculated respectively.

The priority order determining means 34 determines the priority order of the plurality of welding robot possible postures in the order of small change in posture from the welding robot basic posture to the welding robot possible posture for each welding point.
That is, the respective postures of the arms 12 to 17 of the welding robot 10 when the welding robot 10 takes a plurality of welding robot possible postures, and the arms 12 of the welding robot 10 when the welding robot 10 takes the welding robot basic posture. Compare -17 postures. And a high priority is given to a welding robot possible attitude | position sequentially from the thing close | similar to the attitude | position of the arms 12-17 of the welding robot 10 at the time of taking the welding robot basic attitude.

  The welding striking order determination means 35 determines the welding order as a welding striking order for a plurality of welding striking points.

  The welding gun optimum posture determining means 36 has a plurality of divided positions for each welding hit point so that a change in the posture of the welding gun 18 before and after the welding hit order becomes small when welding is performed at a plurality of welding hit points according to the welding hit order. 1 is selected, and the posture of the welding gun 18 at the selected divided position is determined as the optimum posture of the welding gun 18.

  The welding robot optimum posture determining means 37 decides the welding robot possible posture corresponding to the optimum posture of the welding gun 18 at each welding point as the optimum posture of the welding robot 10. Further, when there are a plurality of optimum postures of the welding gun 18 at each welding point, the optimum posture of the welding robot 10 is determined according to the priority order of the welding robot possible postures.

  Below, the procedure which determines the attitude | position of the welding robot 10 is demonstrated, referring the flowchart of FIG.

FIG. 5 is a perspective view of welding workpieces 400 and 500 that are welding objects of the welding robot 10.
The welding workpiece 400 and the welding workpiece 500 partially overlap each other, and a plurality of welding points AA, BB, CC, DD assigned to the welding robot 10 are preset in the overlapping portion.

Returning to FIG. 4, first, in step S1, the welding striking order is determined by the welding striking order determination means 35.
That is, the welding striking order is determined so that the welding works 400 and 500 shown in FIG. 5 are welded in the order of welding striking points AA, BB, CC, and DD.

In step S <b> 2, the split position extraction unit 31 determines a weldable range.
That is, as shown in FIG. 6A, the welding point AA can be welded without causing the arms 12 to 17 and the welding gun 18 of the welding robot 10 to interfere with the welding workpieces 200 and 300 and surrounding structures. The range of postures that the welding gun 18 can take is determined as a weldable range A1. In addition, as with the above-described welding hit points AA, the weldable ranges B1, B2, C1, D1, and D2 are determined for the welding hit points BB, CC, and DD as shown in FIGS. 6 (B) to (D). .
Here, the weldable points AA and CC each have one weldable range, and the weldable points BB and DD each have two weldable ranges.

In step S3, as shown in FIG. 7, the division position extraction means 31 extracts the division position.
That is, as shown in FIGS. 6A to 6D, positions at which the weldable ranges A1, B1, B2, C1, D1, and D2 are divided into three at equal angles are divided into divided positions GA1 to GA4 and GB1 to GB1, respectively. Extracted as GB4, GB5 to GB8, GC1 to GC4, GD1 to GD4, and GD5 to GD8.

In step S4, the welding robot possible posture extracting means 32 extracts the welding robot possible posture.
That is, for the divided position GA1 of the welding hit point AA, first, the optimum welding robot of the welding robot 10 is determined based on the inverse kinematics logic based on the posture that the welding robot 10 can take in accordance with the posture of the welding gun 18 at the divided position GA1. Only one possible posture is extracted. Next, each axis value of the welding robot 10 when this welding robot possible posture is taken is calculated.

  Also, for the divided positions GA2 to GA4, GB1 to GB8, GC1 to GC4, and GD1 to GD8, similarly to the divided position GA1, the optimum welding robot possible posture of the welding robot 10 is extracted one by one, and these welding robots are possible. Each axis value of the welding robot 10 when the posture is taken is calculated.

In step S5, the welding robot basic posture determining means 33 determines the welding robot basic posture.
That is, a predetermined posture of the welding robot 10 is determined as a welding robot basic posture which is a basic posture of the welding robot 10, and each axis value of the welding robot 10 when the welding robot basic posture is taken is calculated.

In step S6, as shown in FIG. 8, the priority order determining means 34 determines the priority order of the welding robot possible postures.
That is, with respect to the divided positions GA1 to GA4 of the welding hit points AA, first, each axis value of the welding robot 10 related to each of the welding robot possible postures calculated in step S4 and the welding robot related to the welding robot basic posture calculated in step S5. 10 axis values are compared. Next, based on the result of comparison, high priority ranks RA1 to RA4 are assigned to the welding robot possible postures in descending order of changes from the respective axis values of the welding robot 10 according to the welding robot basic posture. That is, among the welding robot possible postures RA1 to RA4, the smallest change from each axis value of the welding robot 10 related to the welding robot basic posture is the welding robot possible posture RA1, and the largest change is the welding robot. This is a robot-possible posture RA4.
Also, the welding robot possible posture priority order is determined for the welding hit points BB, CC, DD as well as the welding hit point AA. Thus, since the priority order of the postures of the arms 12 to 17 of the welding robot 10 is determined, the priority order including the posture of the welding gun 18 can be determined.

  In step S7, as shown in FIG. 9, the optimum posture of the welding gun 18 is determined by the welding gun optimum posture determining means 36.

That is, the optimum posture of the welding gun 18 is determined based on the posture of the welding gun 18 at the previous welding point with respect to the welding point AA whose welding order is No. 1. That is, among the postures of the welding gun 18 at the divided positions GA1 to GA4, the one that minimizes the posture change from the posture of the welding gun 18 at the previous welding point is the optimum posture of the welding gun 18 at the welding point AA. To do.
Here, as shown in the hatched region of FIG. 9, the optimum posture of the welding gun 18 at the welding point AA is the posture of the welding gun 18 at the division position GA3.

  Further, the optimum posture of the welding gun 18 is determined based on the optimum posture of the welding gun 18 at the welding point AA where the welding hit order is No. 1 for the welding hit point BB where the welding hit order is No. 2. That is, among the postures of the welding gun 18 at the divided positions GB1 to GB8, the one having the smallest change in posture from the optimum posture of the welding gun 18 at the divided position GA3 is defined as the optimum posture of the welding gun 18 at the welding point BB. To do.

  Referring to FIGS. 6A and 6B, among the divided positions GB1 to GB8, the divided position GB6 is closest to the direction of the divided position GA3. Therefore, as shown in the hatched area of FIG. 9, the optimum posture of the welding gun 18 at the welding point BB is the posture of the welding gun 18 at the division position GB6.

  Further, with respect to the welding hit point CC whose welding hit order is No. 3, the optimum posture of the welding gun 18 is determined based on the optimum posture of the welding gun 18 at the welding hit point BB whose welding hit order is No. 2. That is, among the postures of the welding gun 18 at the divided positions GC1 to GC4, the one having the smallest change in posture from the optimum posture of the welding gun 18 at the divided position GB6 is the optimum posture of the welding gun 18 at the welding point CC. To do.

  6B and 6C, the division position GC4 is closest to the direction of the division position GB6 among the division positions GC1 to GC4. Therefore, as shown in the hatched area of FIG. 9, the optimum posture of the welding gun 18 at the welding point CC is the posture of the welding gun 18 at the division position GC4.

  For the welding hit point DD whose welding hit order is No. 4, the optimum posture of the welding gun 18 is determined based on the optimum posture of the welding gun 18 at the welding hit point CC whose welding hit order is No. 3. That is, among the postures of the welding gun 18 at the divided positions GD1 to GD8, the one having the smallest change in posture from the optimum posture of the welding gun 18 at the divided position GC4 is the optimum posture of the welding gun 18 at the welding point DD. To do.

  6C and 6D, the division position GD6 is closest to the direction of the division position GC4 among the division positions GD1 to GD8. Therefore, as shown in the hatched area of FIG. 9, the optimum posture of the welding gun 18 at the welding point DD is the posture of the welding gun 18 at the division position GD6.

In step S <b> 8, as shown in FIG. 9, the optimum posture of the welding robot 10 is determined by the welding robot optimum posture determination means 37.
That is, the possible welding robot posture corresponding to the optimum posture of the welding gun 18 at each welding point determined in step S <b> 7 is determined as the optimum posture of the welding robot 10. Further, when there are a plurality of optimum postures of the welding gun 18 at each welding point determined in step S7, the determination is made based on the priority order of the welding robot possible postures determined in step S6.

  In step S9, it is determined whether or not the optimum posture of the welding robot 10 has been determined for all the welding points AA, BB, CC, and DD. If this determination is YES, the procedure for determining the attitude of the welding robot 10 is terminated, and if NO, the process proceeds to step S8.

According to the present embodiment, there are the following effects.
(1) According to the attitude determination method of welding robot 10 in the present embodiment, a plurality of division positions are extracted for each of welding points AA, BB, CC, and DD, and further, welding is performed for each of these division positions. One possible robot posture is extracted. Then, one of the plurality of division positions is selected for each of the welding points AA, BB, CC, and DD so that the change in the posture of the welding gun 18 before and after the welding hitting order becomes small. The posture of the welding gun 18 at the selected divided position is the optimum posture of the welding gun 18, and the posture of the welding robot 10 at the selected divided position is the optimum posture of the welding robot 10.

  That is, instead of uniformly determining the position of the welding gun disposed at the center position of the weldable angle region as the optimum position of the welding gun as in the prior art, the weldable range is divided at a plurality of divided positions. The optimum posture of the welding gun 18 and the optimum posture of the welding robot 10 are determined using the divided positions. For this reason, even if the angle of the weldable range is large, the change in the posture of the welding gun 18 and the change in the posture of the welding robot 10 when welding at a plurality of welding points according to the welding stroke order can be reduced. Operation can be reduced. Therefore, the operation of the welding robot 10 can be made smooth, and the cycle time of the welding process can be shortened. Therefore, the optimum posture of the welding robot 10 determined in the present embodiment can be used for off-line teaching as it is, and the man-hours for manual fine adjustment work can be greatly reduced.

(2) Further, there are two weldable ranges for welding points BB and DD, respectively. In this case, for each of the two weldable ranges B1 and B2, a position that divides each of the two weldable ranges B1 and B2 into three equal parts is extracted as a divided position, and for each of the two weldable ranges D1 and D2, each of them is equiangular and three equal A position to be divided is extracted as a division position.
Therefore, even when there is a plurality of weldable ranges at one welding point, the division positions can be extracted from all the weldable ranges, so that the optimum posture for the welding gun 18 and the welding robot 10 can be determined reliably.

(3) When there are a plurality of optimum postures of the welding gun 18 at each welding point, the priority order of the welding robot possible postures is determined. Then, one of the divided positions is selected for each welding hit point so that the change in the posture of the welding gun 18 before and after the welding hit order becomes small and the priority order becomes high.
Therefore, even if there are a plurality of welding robot possible postures for each welding hit point, one welding robot possible posture can be extracted for one welding hit point by using the priority order of the welding robot possible postures.

In addition, this invention is not limited to the above-mentioned embodiment, The deformation | transformation in the range which can achieve the objective of this invention, improvement, etc. are included in this invention.
For example, in step S4, when determining the division positions for the welding points AA, BB, CC, DD, the weldable ranges A1, B1, B2, C1, D1, D2 are divided into three at equal angles, but this is not limitative. Absent. For example, it may be divided into five or six, and the division position may be determined for each predetermined angle such as 5 ° or 10 °. Also, for the welding points BB and DD, the number of divisions and the angle to be divided are set for each of the two weldable ranges B1 and B2, and the number of divisions and the angle to be divided are set for each of the two weldable ranges D1 and D2. You may do it.

  Moreover, although the predetermined attitude | position of the welding robot 10 was determined as a welding robot basic attitude in step S6, it is not restricted to this. For example, an attitude in which each axis value of the welding robot 10 becomes the median value of the movable range of each axis of the welding robot 10 or an attitude with a small amount of deflection of the arms 12 to 17 of the welding robot 10 is determined as the basic attitude of the welding robot 10. May be. The basic posture of the welding robot may be determined with reference to the posture already taught near the welding spot.

It is a figure showing a schematic structure of a welding robot concerning one embodiment of the present invention. It is a block diagram which shows schematic structure of the welding robot attitude | position determination apparatus. It is a schematic diagram for demonstrating a division position. It is a flowchart which shows the procedure which determines the attitude | position of the welding robot which concerns on one Embodiment of this invention. It is a perspective view of the welding workpiece which is the welding object of a welding robot. It is a schematic diagram for demonstrating the division position for every welding hit point. It is a figure which shows the division position for every welding hit point. It is a figure which shows the priority of the welding robot possible attitude | position for every welding spot. It is a figure which shows the optimal attitude | position of the welding robot for every welding spot.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Welding robot 18 ... Welding gun 30 ... Welding robot attitude | position determination apparatus 31 ... Divided position extraction means 32 ... Welding robot possible attitude | position extraction means 33 ... Welding robot basic attitude determination means 34 ... Priority order determination means 35 ... Welding order determination means 36 ... welding gun optimum posture determining means 37 ... welding robot optimum posture determining means 182, 183 ... gun arm 184, 185 ... welding electrode 200, 300, 400, 500 ... welding workpiece AA, BB, CC, DD, OO ... welding point GA1 GA4, GB1 to GB8, GC1 to GC4, GD1 to GD8, GO1 to GO4 ... division positions

Claims (2)

A method for determining a posture of a welding robot having a welding gun for welding at a plurality of welding points set on a welding workpiece,
For each welding point, a range of postures that the welding gun can take when the welding gun can be welded without interfering with the welding workpiece and surrounding structures is determined as a weldable range, and the weldable range is determined. A first step of extracting a plurality of division positions as division positions;
A second step of extracting, as a welding robot possible posture, a posture that the welding robot can take in accordance with a posture of the welding gun for each of the divided positions;
The basic of the welding robot, the determining the attitude of each axis value is the median value of the movable range of each axis of the welding robot welding robot as welding robots basic position, the welding robot from the welding robot basic position A third step of determining the priority order of the welding robot possible postures in ascending order of posture change up to the possible posture;
The order of welding the plurality of welding points is determined as the welding order, and when welding is performed according to the welding order, the change in the posture of the welding gun before and after the welding order is reduced, and the third A welding robot posture determination method, comprising: a fourth step of selecting one of the divided positions for each welding point so that the priority determined in the step becomes higher. In the welding robot posture determination method according to claim 1,
In the first step, when there are a plurality of weldable ranges for each of the welding points, for each of the plurality of weldable ranges, a position that divides the weldable range into a plurality is extracted as a divided position. To determine the attitude of the welding robot.

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