JP3030007B2 - Method and apparatus for planning welding sequence by robot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of welding a plurality of members to a plate-like object by a robot which selects a combination of a welding order and a welding direction of members which has a substantially short cycle time when arc welding is performed. The present invention relates to an order planning method and apparatus.

[0002]

2. Description of the Related Art Conventionally, introduction of a robot has been studied for automation of various productions. For example, JP-A-4-3
No. 03204 discloses a prior art concerning a production planning system that seeks a combination that is almost the shortest time when executing a plurality of processes including a welding process in a high-mix low-volume production. In this prior art, a carry-in time, a work time, and a carry-out time for each process are respectively calculated, and the processes are combined so that a production plan is performed so that the overall required time including the waiting time is almost the shortest. I have. In addition, Japanese Unexamined Patent Application Publication No.
No. 273807 discloses a prior art for creating teaching data for performing spot welding with a plurality of robots.

[0003]

Problems to be Solved by the Invention
In the prior art of No. 4, there is no idea about how to calculate the working time for each process including welding. Also, Japanese Patent Application Laid-Open No. Hei 2-273807 aims to prevent collision between a plurality of robots. It is also important to shorten the welding work time as long as a robot is introduced to improve productivity.

[0004] For example, in a panel structural member in which a stiffener such as a stiffener or a bracket is attached to a flat plate represented by a hull double bottom floor panel of a ship, the order and direction in which a plurality of stiffeners are welded to the flat plate. Therefore, the working time varies greatly. Calculate the required time for each welding location for all the welding locations of all members and calculate the total working time required for all combinations of welding order and welding direction. It should be possible to select the welding order and direction that gives the shortest as the solution. However, when the number of stiffeners increases, the number of combinations of welding order and welding direction becomes enormous. It is very difficult to obtain.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and an apparatus for planning a welding sequence by a robot which can obtain an almost optimum solution within a practical time.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an order planning method for arc welding a plurality of members to the same object by off-line teaching using a robot having an end detection function. Welding time calculation step for individually calculating the sum of the time required for welding the member, the time required for touch sensing, and the time required for movement between operations for each welding direction for the welding location of the member And the order of welding the welding locations of each member, and the welding direction, and the total solution space combining step of obtaining the total solution space, and the constraint condition of performing the bead joining on the end side of the welding from the total solution space is not satisfied. The sum of the time calculated in the welding time calculation step and the time required to move between parts for the solution that is not excluded in the non-cancellation stage and the solution that is not excluded in the non-cancellation stage is almost the shortest. It is the order planning method of welding by robots, which comprises a solution selection step of selecting comprising solutions.

According to the present invention, at the welding time calculation stage, for the welding positions of all members to the same object, the time required for welding the members, the time required for touch sensing, and The total sum of the time required for the movement between works is calculated individually. In the total solution space combination stage,
The total solution space is obtained by combining the welding order and the welding direction of the welding locations of each member. The solution that is a combination of the order of the welding locations and the welding direction that does not satisfy the constraint that the bead joining is performed at the end side of the welding is excluded in the outside stage.
In this way, it is possible to narrow down the target for comparison by summing the time calculated in the welding time calculation step and the time required for moving between the members in the solution selection step, and to narrow the range of the solution to be selected to be almost optimal. The time required to obtain a proper solution can be reduced.

[0008] Further, the present invention, after the end of the step outside the cancellation,
The method further includes a member joining step of grouping a plurality of members that satisfy a joining condition that minimizes a sum of a work time required for individual welding and a time required for movement between the members for the two members, and In the stage, the grouped members are treated as one member.

According to the present invention, a plurality of members are grouped in the member connection stage to reduce the number of members to be handled in the optimal solution selection stage. It is possible to easily obtain an almost optimal solution.

[0010] In the present invention, the robot is mounted on a table which can be moved spatially with respect to a welding point.

According to the present invention, an almost optimum welding direction and sequence can be selected in consideration of the time required to change the position and posture of the robot.

In the present invention, the robots are mounted on the same table so as to form a pair, and both sides of the member can be simultaneously welded.

According to the present invention, it is possible to simultaneously perform welding by a robot mounted on both sides of a member so as to form a pair on a table, so that a plurality of members can be quickly welded to an object. Can be.

[0014] In the present invention, in the step outside the release, the conditions for performing bead joining on the other side at the end side when the other side is connected to one side even if both sides of the member can be welded simultaneously. It must be satisfied.

According to the present invention, while welding both sides of the member at the same time, when welding on one side needs to be interrupted at the connection part of the other member, the other side also stops welding once. The next time welding is performed, the other side is performed so as to satisfy the bead joining condition, so that sound welding as a whole can be automatically performed.

Further, in the present invention, the pair of robots are mounted on a table which can be turned and displaced.
It is characterized in that only solutions whose turning displacement is within a predetermined angle range are selected.

According to the present invention, the table on which the pair of robots are mounted is capable of turning displacement, and only solutions whose turning displacement is within a predetermined angle range at the out-of-release stage are to be selected. Can effectively reduce the number of solutions.

The present invention is also a vertical multi-joint type robot in which an object to be welded is plate-shaped and mounted on a horizontal plane, and the robot is suspended by a portal-type moving device movable on a horizontal plane. A high-speed rotating arc welding torch having a terminal end detection function at the tip of the arm.

According to the present invention, it is possible to perform arc welding of a plurality of members on a plate-shaped object while utilizing the end detection function of a vertical articulated robot suspended from a portal-type moving device. Since the torch for high-speed rotating arc welding has a terminal detection function, it is possible to automatically detect and stop welding during welding without having to detect an accurate terminal position before welding.

Further, the present invention is a sequence planning apparatus for performing arc welding of a plurality of members to the same object by off-line teaching using a robot having a terminal end detecting function, wherein On the other hand, for each welding direction, welding time calculation means for individually calculating the sum of the time required for welding the member, the time required for touch sensing, and the time required for movement between the operations, and From the total solution space combining means for obtaining the total solution space by combining all the welding positions and the welding directions to obtain the total solution space, and the constraint that the bead joining is performed at the end of welding from the total solution space combined by the full solution space combining means An external release means for excluding a solution that does not satisfy the condition, and a coupling condition for minimizing a sum of an operation time required for individual welding and a time required for movement between the members for the two members. Of the solutions based on the member joining means for grouping a plurality of members to be satisfied, the members grouped by the member joining means, and the members that are not grouped, the solution that is not excluded by the outside means for canceling, the welding time calculating means A solution selecting means for summing up the calculated time and the time required for the movement between the members to select a solution in which the total time is substantially the shortest.

According to the present invention, when a plurality of members are arc-welded to the same object, a robot having an end detection function is used. The welding time calculation means individually calculates the sum of the time required for welding the members, the time required for touch sensing, and the time required for movement between the operations for each of the welding locations of all members in each welding direction. Is calculated. The total solution space combining means obtains a total solution space by combining all of the welding order and the welding direction of the welding locations of the members. According to the constraint that the bead joining is performed at the end of welding, the releasing means removes, from the entire solution space, a solution that is a combination of the order of welding locations and welding directions that do not satisfy the constraint.
Further, since a plurality of members are joined by the member joining unit, the number of solutions to be searched when summing the time calculated by the welding time calculating unit and the time required for moving between the members by the solution selecting unit. Is reduced, and an almost optimal solution can be obtained in a practical time.

[0022]

FIG. 1 shows an overall configuration of a welding robot apparatus 1 to which a sequence planning method according to an embodiment of the present invention is applied. The gate type moving device 2 can reciprocate on two parallel rails 3 and 4 laid on the floor.
The gate type moving device 2 is provided with a table 5 which can reciprocate in a transverse direction perpendicular to the running direction. Arms of a pair of vertical articulated robots 6 and 7 are suspended from the table 5 which can be angularly displaced around a vertical axis 5a extending in the vertical direction. High-speed rotating arc welding torches 8, 9 are attached to the ends of the arms of the robots 6, 7, respectively, so that the fillet welding by the twin torch method is possible.

The welding robot device 1 is used for welding a small assembly member 10 typified by, for example, a hull double bottom floor panel of a ship. The small assembly member 10 is formed by arc welding such that a plurality of members 12, 13, 14, 15 are formed on a surface of a flat main plate 11 placed substantially horizontally on a floor surface so as to form a simple fillet weld joint. Formed. Member 12,
Reference numerals 13, 14, and 15 are plate-shaped, and are welded to the main plate 11 in an upright state. Therefore, using the pair of high-speed rotary arc welding torches 8, 9, fillet welding to the same member can be performed simultaneously from both sides.

FIG. 2 shows an example of the small assembly member 10 to be welded. The members 12, 13, 14, 15 and the like are
1 is a stiffener such as a stiffener or a bracket attached to a flat plate. In a large ship, many such small assembly members are combined to form a hull double bottom floor panel or the like. The welding location is previously input as information to the welding robot device 1 by offline teaching.

FIG. 3 shows a flow of information in the welding robot apparatus 1 shown in FIG. The production design office is provided with a CAD system 20 that operates on an engineering workstation or the like abbreviated to EWS or the like, and creates NC information as a three-dimensional machining-related information file 22 based on the hull model 21 that has been set. The processing related information is output to the device 23. The NC information creation device 23 reads the processing-related information file 22 and reads the welding-related information file 22 shown in FIG.
To determine a part that cannot be continuously welded, and perform a division process of the member model as necessary. Subsequently, a work order plan is performed, and after a collision check, NC information for welding each member is created as offline teach information, recorded as a file on an information recording medium 24 such as a floppy disk, and output.

At the production site, the line control device 25 reads the NC information recorded on the information recording medium 24, and according to the offline teach information, the gate type moving devices 2 and 2
The robots 6 and 7 are generally controlled. Robot controllers 26 and 27 for controlling robots 6 and 7, respectively
Causes the robots 6 and 7 to perform a welding operation based on the NC information sent via the communication line 28.

FIG. 4 shows the touch robot (hereinafter referred to as “TS”) when performing fillet welding with the welding robot device 1 of FIG.
) And the principle of performing termination detection. FIG.
(A) shows a basic form in which the member 12 is fillet-welded to the main plate 11. The welding torch 29 moves from the starting end 31 to the end 32 while forming the welding bead 30, and performs arc welding for erecting the plate-shaped member 12 on the surface of the main plate 11. When the robot automatically moves the welding torch 29 to perform the arc welding, it is necessary to detect the exact position of the start end 31 and the end end 32 by TS. The CAD system 20 as shown in FIG. 3 outputs the processing-related information for the model.
Is likely to deviate from the position set for the model.

FIG. 4B shows a state in which TS is performed for the terminal end 32. When performing TS, use welding torch 2
9 repeatedly and at a low speed so as not to give an impact to the welding torch 29, the main plate 11 and the member 12.
Needs to be brought into contact with the surface of the main plate 11 or the member 12. Based on the contact point 33 and the movement amount of the welding torch 29, the actual positions of the start end 31 and the end 32 are detected. FIG. 4 (a)
In the basic fillet welding as shown in (1), TS is performed on two points, a start end 31 and an end end 32, and thereafter, arc welding is performed. TS requires a considerable amount of time, and it is preferable to omit TS as much as possible in terms of productivity.

FIG. 4C shows the welding robot apparatus 1 shown in FIG.
The principle of high-speed rotating arc welding performed by the torches 8 and 9 for high-speed rotating arc welding will be described. By monitoring changes in welding current and voltage while applying rotation 34 to the torch 8 for high-speed rotating arc welding, if the periphery of the terminal 32 is an open space, the position of the terminal 32 can be detected. The TS for 32 can be omitted. Also, when the welding torch reaches the welding bead 30 where welding has already been completed, it can be detected from changes in welding current and voltage. The principle of end detection by such high-speed rotating arc welding is described in, for example, Japanese Patent Application No. 9-66 filed by the present applicant.
516, etc.

FIG. 5 shows the NC information creating device 23 shown in FIG.
1 shows an example of a subassembly member 10 which is a target of a work sequence plan according to the present invention. On one flat main plate 11, five members 12 to
16 are arranged. In the operation of welding each of the members 12 to 16 to the main plate 11, the time required for the fillet welding itself, the time required for the TS, and the air cut time required for the movement between the members 12 to 16 are required. . The work sequence planning is a combination optimization problem that minimizes the total value of these times, and is a problem similar to the traveling salesman problem (which may be abbreviated to TSP from Traveling Salesman Problem). In the combination optimization problem, an optimal solution can be obtained by evaluating and searching for all combinations and adopting an optimal solution. However, in general, it takes an enormous amount of time to perform a full search. For this reason, GA (Genetic Algorithm) and SA (Simulated
Annealing) is used to obtain a nearly optimal solution within an appropriate time. Alternatively, characteristics are analyzed for each problem, and a solution is devised and applied for each problem.

Each of the members 12 to 16 with respect to the main plate 11
For example, fillet welding is performed in a state temporarily attached by spot welding. The following three items are to be determined in the work order plan.

(1) Welding order between members (2) Welding direction of each member (3) Assignment of torch for high-speed rotating arc welding on both sides of each member The main plate 11 is rectangular, and its longitudinal direction is shown in FIG. Is the direction in which the gate-shaped moving device moves along the rails 3 and 4, and the transverse direction perpendicular to the direction is the y direction. The pair of high-speed rotating arc welding torches 8 and 9 use one high-speed rotating arc welding torch 8 as a master and the other high-speed rotating arc welding torch 9 as a slave.

FIG. 6 is a sectional view of a work 16 to be welded as shown in FIG.
An example is shown in which the welding order 〜, the welding direction indicated by an arrow, and the assignment of the torches 8, 9 for high-speed rotation arc welding indicated by a double circle and a single circle are shown as six members A to F. The member 16 is divided into the member E and the member F because the member 15 is connected to one side of the member 16 when both sides of the member 16 are simultaneously welded by the pair of high-speed rotating arc welding torches 8 and 9. This is because continuous welding cannot be performed, and it is necessary to separately weld the two members E and F.

FIG. 7 shows that the member 16 of FIG.
The restriction of the bead joining generated when dividing as shown by F will be described. That is, as shown in FIG.
When a middle portion of another member 16 is joined to the tip of the member 16 and is combined in a substantially T-shape, the side surface of the member 16 cannot be welded at one time. At this time, FIG.
As shown in FIG. 6, the other member 16 needs to be divided into two members 16α and 16β corresponding to the members E and F in FIG. 6 and welded. In FIG. 7B, the portion "-" shown in FIG. 7 (b) requires the bead splicing without sacrificing the cycle time due to the necessity of quality assurance. Further, in the high-speed rotating arc welding method, as shown in FIG. 7C, bead joining can be automatically performed only at the end of welding. For this reason, a local order relation occurs between the divided members E and F due to the necessity of performing the bead joining, which is a constraint condition of the bead joining.

FIG. 8 shows a concept of narrowing down the solution space by the work order plan of the NC information creating device 23 of FIG. In general, in the combination optimization problem, if the number of elements to be combined increases even one, the number of solutions to be searched increases significantly.
Further, a plurality of members 12 to 1 are attached to a main plate 11 as shown in FIG.
In the case of optimizing the order in which the welding of No. 6 is performed, there are many items to be determined, and each item affects each other in planning the work order. Therefore, the total solution space 40 becomes large and complicated. Therefore, an item that can be determined independently is determined without significantly deteriorating the optimality of the solution, the number of combinations is reduced, and then a full search is performed to adopt a nearly optimal solution. The procedure for searching for a solution is performed as follows.

(1) The torch allocation on both sides of each member when welding each member is determined. (2) For each member, for each welding direction, the total of the operation time required for welding the member, the time required for the TS, and the time required for moving between the operations is calculated. (3) When there is a bead joining constraint between certain members,
Semi-fixation is performed to limit the welding order and direction in those members to some extent. (4) If the number of members is large, the members are grouped based on a rule described later until the number becomes an appropriate number, and at this time, the welding order and the direction of the members in the group are semi-fixed. (5) Full search is performed for all combinations of groups and ungrouped parts, and the solution with the shortest cycle time is adopted.

When the procedure (1) is completed, the total solution space 40 is narrowed down as in the solution space 43 after the torch assignment in FIG. If the solution space is limited by the bead joining constraint according to the procedure (3), the solution space 4 limited by the bead joining constraint in FIG.
4, the solution space is further narrowed down, and only a part of the feasible solution 41 is to be searched. Further, if the number of members is reduced in the procedure (4), the solution space is reduced as in the solution space 45 after grouping in FIG. 8, and it is possible to perform a full search within a practical time.

FIG. 9 shows the principle of assigning a torch in the procedure (1).

In general, frequent rotation of the turning shaft 5a causes an increase in cycle time. In particular, when the turning speed is slower than the traveling or traversing speed in the gate type moving device 2, it is necessary to reduce the turning operation as much as possible to shorten the cycle time. FIG. 9A shows a state in which the rotation angle θ of the turning shaft 5a is limited to a range of −90 ° <θ ≦ 90 °. An equivalent torch assignment is shown in FIG.
It is also obtained as shown in FIG. Where θ ≦ −90 °
Or, θ> 90 °, and the absolute value of the rotation angle θ increases. By the torch assignment of (1) above,
If the torch assignment based on the member direction is performed in advance, the solution space can be significantly reduced and narrowed down as in the solution space 43 after the torch assignment shown in FIG.

FIG. 10 shows the concept of calculating the working time for each welding direction in the procedure (2) described above. In the combination of the members 15 and 16 in FIG. 7, both ends on the member 15 side are point A and point B as shown in FIG. As shown in FIGS. 10B and 10C, the welding directions are as follows.
Two types are searched. In FIG. 10B, a TS is required at the start point A and the end point B, and the torch moving time for the TS is also required. In FIG. 10C,
Although a TS is required at the start point B, the end point A is an open space, so the end is automatically detected during welding by using a high-speed rotating arc welding method, and the TS is detected.
Is unnecessary. As described above, since the operation time including the TS differs depending on the welding direction, it is necessary to calculate the operation time for each welding direction and prepare for performing the full search.

FIG. 11 shows a process for semi-fixing a member having a bead joining restriction in the above-mentioned procedure (3). As shown in FIG. 11A, the member 16 is connected to the members 16α, 16α.
Divide into β. As shown in FIGS. 11 (b) and 11 (c), one member 16 that satisfies the bead joining constraint is replaced and semi-fixed. Since the welding order and direction as shown in FIGS. 11D and 11E do not satisfy the bead joining constraint, they are excluded as unexecutable combinations.

FIG. 12 shows an outline of the processing for grouping members in the above-mentioned procedure (4). The solution space explosively expands as the number of members to be welded increases. Therefore, it is desirable that the number of members is small at the time of the full search in the procedure (5). Therefore, based on certain rules, for example, FIG.
Of the six members 17A to 17F shown in FIG. 2A, two members 17B and 17C are grouped to form one group shown in FIG.
Treated as one member 17G, and the welding order and direction within the group are semi-fixed. As a rule for grouping, it is determined that the sum of the operation time required for individual welding and the time required for movement between members is minimized for all of the currently targeted members. Follow this rule 2
Search for a combination of two members and replace with one member.
The grouping is repeated until the number of members to be planned for the operation sequence is within the range in which the entire search can be performed within a practical time.

FIGS. 13 (a) and 13 (b) show the plan results of the automatic work order planning system according to the present embodiment and the plan results of the case of a human being in comparison. The double circles indicate the allocation side of the high-speed rotary arc welding torch 8 on the master side (single circles indicating the allocation of the torch on the slave side are omitted). With the work order planning system,
Thus, the emphasis is placed on reducing the time required for TS, and the result of utilizing the end detection function of high-speed rotating arc welding is obtained. In the case of humans, the welding sequence and direction that seem to shorten the air cut time are selected, and the time required for TS has not been reduced. Table 1 below shows the comparison results of FIGS. 13 (a) and 13 (b).

[0044]

[Table 1]

FIG. 14 shows an outline of the entire procedure including the work sequence planning of the present embodiment described above. In the case where the members 12 to 16 are welded to the main plate 11 in FIG.
In addition to horizontal welding such as welding of the members 12 to 16 to the main plate 11, it is necessary to perform vertical welding such as welding between the members 12 to 16. Here, it is assumed that horizontal welding is performed and then vertical welding is performed. The work sequence planning is started from step a1. In step a2, the rotation angle of the turning shaft is determined according to the conditions shown in FIG. 9 for both the vertical welding data and the horizontal welding data. In step a3, it is determined whether the target welding location is vertical welding data or horizontal welding data.

If it is determined in step a3 that the data is vertical welding data, in step a4, the coordinates (x, y) of the starting end and the end of each welding direction, the rotation angle θ of the turning shaft,
And the sum of the time required for welding the member, the time required for the TS, and the time required for movement between the operations.
In the next step a5, until the number of members becomes an appropriate number,
After grouping the members, a full search is performed to determine the order.

If it is determined in step a3 that the data is horizontal welding data, it is determined in step a6 that the data is grouped composite data having a partial order or single data having no partial order. Determine if there is. For the composite data, in step a7, the order in the composite data is determined, representative data representing the composite data is created,
Start and end coordinates (x, y) for each welding direction,
The rotation angle θ of the revolving shaft and the sum of the time required for welding the members, the time required for TS, and the time required for movement during the work are calculated. Step a
8, the start and end coordinates (x,
y), the rotation angle θ of the revolving shaft, and the sum of the time required for welding the members, the time required for TS, and the time required for movement between operations. When the calculation processing of step a7 or a8 is completed for each data, step a6 is performed until the calculation processing of all data is completed.
Repeat the following. In step a9, after the members are grouped until the number of members becomes an appropriate number, a full search is performed to determine the order.

When step a5 or a9 is completed, in step a10, the vertical welding data is added after the horizontal welding data, and the rotation angle of the turning shaft is changed to ± 180 ° with respect to the horizontal welding data to shorten the cycle time. If there is anything that can be done, change the rotation angle of the pivot axis to ± 180 °. At step a11, the work sequence plan ends.

FIG. 15 shows a schematic configuration of a welding robot device 51 used in another embodiment of the present invention. This welding robot device 51 is similar to the welding robot device 1 of FIG. 1, and corresponding portions are denoted by the same reference numerals and redundant description is omitted. The welding robot device 51 of the present embodiment includes:
Table 5 in which a single articulated robot 6 has no pivot axis
Is a single torch system in which only one high-speed rotating arc welding torch 8 is mounted. In the single torch method, it is not necessary to consider the rotation angle of the turning shaft.

FIG. 16 shows an example of an object to be welded in this embodiment. When the fillet welding in which the five members 12 to 16 are erected on the main plate 11 is performed using the high-speed rotary arc welding torch 8, one side 12a, 12b;
3a, 13b; 14a, 14b; 15a, 15b must be separately welded. As for the member 16, two portions 16 a,
16b, and three places are welded together with the other side 16c.

FIG. 17 shows an outline of a work sequence plan according to this embodiment. The operation sequence planning is started from step b1, and in step b2, it is determined whether the target welding location is the vertical welding data or the horizontal welding data. If it is determined that the data is vertical welding data, in step b3, the coordinates (x, y) of the start end and the end for each welding direction, the time required for welding the member, the time required for TS,
The total time required for the movement between the operations is calculated. In the next step b4, after the members are grouped until the number of members becomes an appropriate number, a full search is performed to determine the order.

When it is determined in step b2 that the data is horizontal welding data, in step b5, the coordinates (x, y) of the start and end for each welding direction, the time required for welding the member, The sum of the time required for the TS and the time required for moving between works is calculated. In step b6,
After grouping the members until the number of members becomes an appropriate number, a full search is performed to determine the order. When step b4 or b6 is completed, the vertical welding data is added after the horizontal welding data in step b7, and the work sequence planning is ended in step b8.

In each of the embodiments described above, the solution can be narrowed down, and the work sequence can be planned in a few seconds by using the EWS in the NC information generating device 23 shown in FIG. If the number of welding locations to be welded increases, the number of members can be reduced by grouping, so that an almost optimal solution can be easily obtained within a practical time of about several minutes. There are many types of subassembly members 10 necessary for one ship, and an almost optimal solution can be easily and quickly obtained for each individual subassembly member 10, so that productivity such as ship construction can be improved. it can. Further, the present invention can be applied to other fields of manufacturing and construction that require fillet welded joints by arc welding, and similar effects can be obtained. Further, the present invention can be applied not only to the vertical articulated robot but also to other types of robots.

[0054]

As described above, according to the present invention, it is possible to narrow the solution space when selecting an almost optimal solution while excluding unrealizable solutions while targeting all possible solutions. As a result, a combination of the welding sequence and the direction that minimizes the time required for welding can be selected within a practical time.

According to the present invention, a plurality of members can be grouped and handled as one member at the member connecting stage. Therefore, even if the number of members to be welded to the same object is large, It is possible to easily obtain a combination of the welding order and the direction of the members that has the shortest time within a practical time range.

According to the present invention, a combination of a work sequence and a direction in which the work time for welding a plurality of members to the same object by using a robot mounted on a spatially movable table is substantially minimized. Can be easily obtained.

Further, according to the present invention, a robot which is provided as a pair on the same table can easily obtain a combination of a welding sequence and a direction in which almost the shortest time can be obtained when welding both sides of a member at the same time. be able to.

According to the present invention, when welding both sides of a member at the same time, even if the welding is interrupted on one side and bead joining is required on the other side, the order of performing arc welding under appropriate conditions And the combination of directions can be easily selected.

According to the present invention, the combination of the welding sequence and the welding direction of the plurality of members is selected so that the time required for welding as a whole is substantially minimized in consideration of the turning displacement of the table. Can be.

According to the present invention, the welding by the vertical articulated robot suspended from the ceiling-type moving device can be easily performed within a practical time by combining the welding sequence and the direction in which the required time is almost the shortest. Can be selected.

Further, according to the present invention, when a plurality of members are arc-welded to the same object, a robot having a terminal end detecting function is used, and the welding time calculation means is used for the welding positions of all members. The sum of the time required for welding the member, the time required for TS, and the time required for movement between operations is calculated. The release outside means excludes combinations that do not satisfy the constraint that bead joining is performed at the end side of welding among combinations of welding locations in all solution spaces obtained by the all solution space combination means, and further, the members are joined by the member joining means. Is reduced, the solution selecting means can select a solution that requires the shortest required time within a practical time range.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of a welding robot device 1 to which an embodiment of the present invention is applied.

FIG. 2 is a perspective view of a small assembly member 10 which is an example of a welding target in FIG.

FIG. 3 is a block diagram showing a flow of information for controlling the welding robot device 1 of FIG.

FIG. 4 is a perspective view showing a TS and an end detection function of the welding robot device 1 of FIG. 1;

FIG. 5 is a plan view showing a work sequence planning target of the embodiment of FIG. 1;

6 is a plan view showing an example of a solution for the welding target in FIG.

FIG. 7 is a simplified plan view showing a bead joining restriction generated for members 15 and 16 in FIG. 6;

FIG. 8 is a solution space diagram showing a range of solutions to be searched in the work order plan of the embodiment of FIG. 1;

FIG. 9 is a simplified plan view showing a constraint condition of a rotation angle around a turning axis 5a for the torch assignment in the embodiment of FIG. 1;

FIG. 10 is a simplified plan view showing a difference between a time required for TS and a time required for movement between operations according to a welding direction in the embodiment of FIG. 1;

FIG. 11 is a simplified plan view showing a semi-fixing process based on a bead joining constraint in the embodiment of FIG. 1;

FIG. 12 is a simplified plan view showing grouping of members in the embodiment of FIG. 1;

FIG. 13 is a simplified plan view showing a comparison between the work order planning system of the embodiment of FIG. 1 and solutions by humans;

FIG. 14 is a flowchart showing a procedure of a work order planning of the embodiment of FIG. 1;

FIG. 15 is a perspective view showing a schematic configuration of a welding robot device 51 according to another embodiment of the present invention.

FIG. 16 is a plan view showing an object of a work sequence plan according to the embodiment of FIG. 15;

FIG. 17 is a flowchart showing a procedure of a work sequence planning in the embodiment of FIG. 15;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1,51 Welding robot device 2 Gate type moving device 5 Table 5a Rotating axis 6,7 Vertical articulated robot 8,9 Torch for high-speed rotary arc welding 10 Small assembly member 11 Main plate 12,13,14,15,16, 16α, 16β, 1
7, 17A to 17G, 18 members 20 CAD system 22 machining-related information file 23 NC information creation device 25 line control device 26, 27 robot control device 30 welding bead 31 start end 32 end 33 contact point

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Koichi Fukumoto 1-1, Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries, Ltd. Inside the Akashi factory (56) References JP-A-9-164483 (JP, A) 63-80971 (JP, A) JP-A-7-88648 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G05B 19/4093 B23K 9/12

Claims (8)

(57) [Claims] 1. A robot having an end detection function,
This is an order planning method for performing arc welding of a plurality of members to the same target object by offline teaching, and for a welding position of all members, for each welding direction, a time required for welding the members, Welding time calculation stage for individually calculating the sum of the time required for touch sensing and the time required for the movement between operations, and the total solution space by combining all the welding positions and welding directions of the welding points of each member Welding time calculation is performed for all solution space combining stages, the solution phase that excludes the solution that does not satisfy the constraint conditions for performing bead joining at the end of welding, and the solution that is not excluded in the solution phase. Summing the time calculated in the step and the time required for movement between members, and selecting a solution in which the total time is almost the shortest. Order planning method. 2. After completion of the non-cancellation step, a plurality of members satisfying a coupling condition that minimizes the sum of the work time required for individual welding and the time required for movement between the members are grouped for the two members. 2. The method according to claim 1, further comprising the step of joining members to be combined, wherein in the solution selecting step, the grouped members are treated as one member. 3. The method according to claim 1, wherein the robot is mounted on a table which can be moved spatially with respect to a welding point. 4. The method according to claim 3, wherein the robots are mounted on the same table so as to form a pair, and both sides of the member can be welded at the same time. 5. In the releasing step, even if both sides of the member can be welded at the same time, if another member is connected to one side, it is necessary to satisfy a condition for bead joining on the other side at the terminal side. 5. The method according to claim 4, wherein the welding sequence is planned by the robot. 6. The robot according to claim 1, wherein the pair of robots are mounted on a table capable of turning and displacing, and in the step outside the release, only solutions whose turning displacement is within a predetermined angle range are selected. Item 4. The method for planning a welding sequence by a robot according to Item 4 or 5. 7. The robot according to claim 7, wherein the object is a plate-shaped object, and the object is placed on a horizontal surface. The robot is a vertical articulated robot suspended from a ceiling-type moving device movable on a horizontal surface. The method for planning a sequence of welding by a robot according to any one of claims 1 to 6, further comprising a torch for high-speed rotation arc welding having a terminal end detection function at the tip. 8. Using a robot having an end detection function,
This is a sequence planning device for arc welding of multiple members to the same target object by offline teaching, and for a welding position of all members, for each welding direction, the time required for welding the members, Welding time calculation means for individually calculating the sum of the time required for touch sensing and the time required for movement between operations, and the total solution space by combining all the welding positions and welding directions of the welding points of each member From the total solution space combining means for obtaining
Means for release that excludes the solution that does not satisfy the constraint that the bead joining is performed at the end of welding, and the sum of the working time required for individual welding and the time required for moving between the members for the two members is minimized. Welding is performed on the solution based on the member joining means for grouping a plurality of members satisfying the following joining conditions, the members grouped by the member joining means, and the members not grouped, which are not excluded by the releasing means. A solution selecting means for summing the time calculated by the time calculating means and the time required for the movement between the members, and selecting a solution having a shortest total time. apparatus.