JP2910471B2 - Automatic generation system of welding robot operation program - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for automatically generating welding robot data when a plurality of welding robots work on one work, and more particularly, to a bridge panel using a teaching-less CAD / CAM system. The present invention relates to an automatic generation system of a welding robot operation program that enables automatic welding such as.

[0002]

2. Description of the Related Art Conventionally, teaching work of a work program of an industrial robot such as a welding robot has been performed by teaching the operation of a robot on a production line. In recent years, instead of such a teaching method, an offline teaching system capable of performing a teaching operation of a robot at a place different from a production line has been developed (Japanese Patent Laid-Open No. Sho 62-62).
No. 108314, JP-A-2-262986, JP-A-Hei3
No. 109608), the operation rate of the robot has been improved, and the teaching work has been simplified.

[0003]

However, in the above-mentioned offline teaching system, it is common that an operator performs some work while heading for a CRT. In this system, the intervention of the operator is indispensable. It is one of the factors that hinder the transition. Furthermore, in the case where a plurality of robots operate for one work, at present, the offline teaching system itself cannot be applied. JP-A-62
Even in the case of the technique disclosed in Japanese Patent Application Laid-Open No. 108314, the operation areas of the robots for one work are determined so as not to overlap each other. It is not much different from offline teaching.

On the other hand, in the field of heavy industry where the target work is very large and there are almost no identical members, such as the manufacture of a bridge panel or the like, the work time in the production design process is enormous in the conventional general offline teaching system. And is virtually unusable.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a system for automatically generating a welding robot operation program capable of achieving a large labor saving in teaching work.

[0006]

SUMMARY OF THE INVENTION According to the present invention, when a plurality of welding robots work on one work, an operation program of the welding robot is used by using only the shape information of the work and the welding design information. The above problem has been solved by providing a system for automatically generating the. That is, the configuration characterized by the present invention is a work information input means for inputting work shape information and work welding design information,
And weld line determining means for generating and determining the dissolved <br/> tangent to each mounting member on the basis of the inputted work shape, the welding robot
The torch cross-section and the work cross-section
Check using the shape, if there is interference, torch attitude
Can be avoided by changing the value within a certain range
The interference avoidance point or the interference occurrence point where
Interference avoiding means generated on a tangent line, dividing the welding line into a plurality of robot operation regions, and dividing a region dividing point on the welding line
And operating region dividing means for generating a, a welding order determining means for determining the welding order of the weld line for each of the robot operation area, respectively <br/> operation pattern for each welding point constituting the welding line And operation pattern determining means for determining.

Here, the work shape information is the geometric information of the target work, and specifically, the outer shape of the panel, the position information of the mounting line of the mounting member, the shape and the cross-sectional shape of the mounting member, and the like. . Further, when the target work is composed of a plurality of panels, the position information of the butting line is also included. Also, the welding design information for each mounting member is
Welding methods such as horizontal fillet welding, groove welding, butt welding,
These are welding design conditions such as fillet leg length and groove shape. It is assumed that such information is defined in the CAD system.

[0008]

According to the present automatic welding system, the workpiece shape information is taken in, and the workpiece is arranged at an appropriate position in the operating area of the welding robot. Then, both end points which are the welding start point and the welding end point of the welding line are defined based on the work attachment line information. Further, at the intersection of the welding lines, the robot and the workpiece are checked for interference using the robot shape data defined in advance as the welding robot model and the shape information of the mounting member of the workpiece shape information. If it occurs, a point for avoiding interference is newly defined in the interference part. It is checked whether or not the welding line composed of the above points is within the operation range of the robot, and it is defined which robot will weld which welding line. Here, for a welding line extending over a plurality of robots, two new points are defined at the intersections of the boundary line and the welding line in order to divide the welding line in each operation range. By this process, all welding lines are allocated to each robot.

Next, the welding order in each robot is defined so that the dead time is minimized. Further, for each point on the welding line, an optimum operation pattern is selected using attribute information indicating which type of the point is in the above definition and geometric attribute information at the point. Using the robot information generated by the above processing, a robot operation program is automatically generated, and a plurality of robots can be operated.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a bridge panel according to an embodiment of the present invention.

(1) Panel production line management system The box girder bridge panel production line has a web panel and a flange panel independent lines installed in parallel. Both lines of the web panel and the flange panel are shown in FIG. It is centrally managed by computers in the central control room as shown below.

In FIG. 1, reference numeral 10 denotes a host computer comprising a CAD / CAM system, 1 denotes a computer for controlling a web line, 2 denotes a computer for controlling a flange line, and 3 denotes control of data transmission / reception between the three types of computers. It is a data control computer. Further, a tacking device 110, a welding device 120, a strain removing device 130, a drilling device 140, and a finishing device 150 are arranged on the web line, and each device is sequence-controlled by the web line controller 4. 5 is an FA computer of the welding device 120, and 6 is a drilling device 14.
0 FA computer. In addition, the joining device 160, the tacking device 170, the welding device 18
0, straightening device 190, drilling device 200, finishing device 2
Each of these devices is sequence-controlled by the flange line controller 7.
Reference numeral 8 denotes an FA computer of the welding device 180, and reference numeral 9 denotes an FA computer of the drilling device 200.

The information to be centrally managed is CAD / CAM information for controlling the operation of the robot, and production management information such as the sequence of each device and operation status monitoring. In addition,
Here, an automatic generation system of an operation program for operating the welding robot system will be mainly described.

(2) Applicable Panel First, FIGS. 9 and 10 show typical configurations of a web panel and a flange panel which are objects of the present invention. The standard panel size is 3 m wide and 12 m long for both panels. As shown in FIG. 9, the web panel 100 has a web plate 102 on which a plurality of vertical stiffeners 103 and a plurality of horizontal stiffeners 104 are attached vertically and horizontally. The flange panel 101 has a flange plate 10 as shown in FIG.
5, a plurality of vertical ribs 106 are attached in the length direction, and the welding line may be discontinuous at a drain hole, a diaphragm attachment position, or the like.

(3) Automatic Web Panel Welding Apparatus FIG. 11 shows an outline of an automatic web panel welding apparatus 120. The automatic welding device 120 is provided with a gate-shaped fixed frame 12.
In this figure, eight articulated welding robots 123 each having a transverse axis 122 as an external axis are mounted on the apparatus 1 at an interval of 2 m in the length direction of the web plate in a suspended state. This welding robot 123 has a known high-speed rotating arc welding torch 124 attached to the tip of an arm of a six-axis articulated robot, and has an automatic welding line tracing function using an arc sensor, a member end detection function, and a bead joint detection function. Have. Then, since each robot 123 simultaneously welds the shared area of 2 m pitch, the welding operation time can be made substantially constant regardless of the size of the panel. Adjacent robots are configured to avoid collisions between the robots by optimizing the welding order described later and checking the robot for interference.

(4) Automatic Flange Panel Welding Apparatus FIG. 12 shows an outline of an automatic flange panel welding apparatus 180. The automatic welding device 180 includes a traveling gantry 181.
On the upper side, three sets of traverse axes 182 are provided as external axes, and on each traverse axis 182, two articulated welding robots 183 having the same configuration as the robot 123 are respectively installed in a ceiling-suspended position. The vertical ribs 106 are welded simultaneously by two welding robots 183 on each horizontal axis with the welding torch 184 facing both sides of the vertical ribs 106, and welding the three vertical ribs 106 in one gantry run. can do.
In addition, each robot 183 individually extinguishes and reignites an arc at a discontinuous portion of a welding line such as a drainage hole or a diaphragm mounting position, so that intermittent welding can be performed while the gantry is running at a constant speed. .

(5) Teaching-less CAD / CAM system FIG. 2 shows a teaching-less CAD / CA for automatically generating operation data of a welding robot in the welding system shown in FIG.
1 shows an outline of an M system. In FIG.
A work information database 11 of the host computer 10 stores work shape information and work welding design information. Reference numeral 12 denotes a robot operation program automatic generation system for extracting the work information and automatically generating a robot operation program. Reference numeral 13 denotes a robot database that stores the generated robot operation program. The generated program is obtained by arranging the operation pattern, the position information, and the welding information in the operation order. The processing up to this point is performed by the host computer 10.

Next, the following processing is performed by the factory FA computer 5 or 8, and based on robot data,
The FA computer 5 or 8 extracts necessary information from the operation pattern database 14 and the welding condition database 15, and the robot data processing system 16 converts the information into robot operation data, and transfers the data to each of the welding robots 123 and 183.

Hereinafter, details of the robot operation program automatic generation processing performed by the host computer 10 will be described. In the work shape information, the outer shape of the panel, the position information of the mounting line, the shape and the cross-sectional shape of the mounting member, and the like are defined. When the target work is composed of a plurality of panels, the position information of the butting line is also included. Furthermore, welding design conditions such as horizontal fillet welding, groove welding, butt welding, fillet leg length, groove shape, and the like are defined as welding design information for each mounting member. It is assumed that such information is defined in the CAD system. FIG. 3 shows an example of work information to be registered in the database 11. For each panel name, a designated value is registered for each item of material attribute, surface attribute, shape attribute, stiffening member attribute, and welding attribute.

Hereinafter, a case of horizontal fillet welding of a web panel will be described as an example. FIG. 4 shows the flow of processing and the processing contents of the robot operation program automatic generation system 12, and FIG. 5 is a flow chart of the entire system.

A. Work Information Input Process (Step S1) First, the work information input means 21 of the present system reads the target work information from the database 11 of the host computer 10 into the robot database 1 in the system.
Take in 3. In FIG. 4, reference numeral 31 denotes an attachment line of the target panel 100, which also serves as one welding line as described below. Numeral 32 denotes a butt joint line.

B. Welding Line Determination Process (Step S2) Next, the welding line determination means 22 extracts the position information of the attachment line from the work information and defines the welding line. The attachment line is generally defined by one line, and the attachment line 31 is located at a position separated from the attachment line by the thickness of the attachment member.
A line 33 is generated in parallel with the above, and these two lines 31, 33 are defined as a welding line. This attachment line may be straight or curved. With the above processing, the welding line 31,
33 are defined and points 35, 3 are located at both ends of each weld line.
6 is generated. These points 35 and 36 are defined as end points. That is, the end points 35 and 36 mean a welding start point or a welding end point. In the case of a curve, a point 37 is generated at a position where the line segment is divided equally as shown in FIG. This point 37 is defined as a curvature midpoint.

C. Interference avoidance processing (step S3) The interference avoiding means 23 for avoiding interference between the work and the robot first checks the interference between the mounting member to be welded and the robot. When the target member is a shaped steel or the like, it may not be possible to take a torch posture capable of welding. Therefore, first, interference is checked with a standard welding posture (for example, a torch angle of 45 °), and if there is interference, the torch posture is changed within a specific range. This range is a posture range in which the quality in welding can be maintained. FIG. 7A shows a method of interference check based on a change in the torch attitude. If interference cannot be avoided due to a change in the torch attitude, it is excluded from robot welding targets as welding lines that cannot be welded. The above is the processing for avoiding interference between the mounting member to be welded and the robot.

Next, an interference check between the mounting member close to the target member and the robot is performed. First, a part that may cause interference is obtained. As one, an intersection of welding lines is obtained for all welding lines. This is because interference is likely to occur at the intersection of two welding lines. Also, when the welding line is close to the welding line, interference is likely to occur.
As shown in FIG. 7B, this distance generates line segments 37 and 38 parallel to the one welding line 33 at a certain distance from the other welding line 33, and the other line segments become the other line segments. When it intersects with 39, the position of the perpendicular drawn from the intersections 40 and 41 to the welding line 33 is a candidate point. At each of the points 42 and 43 obtained in this way, the interference between the welding robot and the work is checked. When interference occurs, it is checked whether the interference can be avoided by changing the torch attitude at that position. If the interference can be avoided, the point is defined as the interference avoidance intermediate point 43. However, the torch position can be changed only within a specific range because of welding restrictions. If interference cannot be avoided even by changing the torch attitude, a point is moved along the welding line to a position where no interference occurs, and the point is defined as an interference occurrence point 42. Since the welding must be discontinuous at the interference occurrence point 42, the original welding line is left behind by the interference occurrence point.

D. Operation Area Division Processing (Step S4) The operation area division means 24 assigns each welding line to a plurality of robots. Here, it is assumed that a plurality of welding robots are arranged adjacent to each other, and that the target workpiece is welded by the plurality of robots. Specifically, a welding line within the operation range of a specific robot is defined as a welding line of the robot. However, one welding line may span the operation range of a plurality of robots.
For example, as shown in FIG. 8, this is a case where the horizontal welding lines 31 and 33 extend over the operation range of a plurality of robots. In this case, since welding cannot be continuously performed by one robot, the welding lines 31 and 33 are divided. Processing includes welding line 3
Points 45 and 46 are generated at intersections of the boundary lines (region division lines) 44 of the regions 1 and 33 and the points 45 and 46 are defined as region division points. When one welding line 47 completely enters the region of a plurality of welding lines and can be welded by either robot, welding is performed by a robot having a small total welding length for the purpose of leveling work.

E. Welding Order Determination Process (Step S5) The welding order determination means 25 defines the welding order of welding lines within the operation range of the robot. Basically, choose the order that minimizes the air cut time,
In a welding system in which a plurality of robots are adjacent to each other, it is necessary to give top priority to avoiding interference between the robots. Here, for the purpose of avoiding interference, an interference area where interference may occur is set at the boundary of the operation area. In the robots adjacent to the left and right robots, interference regions are provided on the left and right sides of the robot. The welding order is such that the welding line in the interference area on the left side, the welding line in the central area where there is no interference, and the welding line in the interference area on the right side. Specifically, first, the welding order of the welding line group in which a part of the welding line is included in the interference range on the left side is defined. After that, the welding order in the central welding line group without interference is defined. Finally, the welding order of the welding line group in the right interference range is defined. Here, the welding direction of each welding line is basically a counterclockwise direction, but the welding direction is always defined from left to right for the region-divided welding line due to restrictions on bead lap welding. In such processing, interference between robots can be minimized, but cannot be completely avoided. Therefore, the above 3
The robots are interlocked in the three parts to prevent the robots from interfering with each other as a robot control function. Specifically, interference is avoided by interlocking so that welding on the left interference area does not start until the robot on the right has completed welding on the welding line within the interference area on the left of the robot. ing.

F. Operation pattern determination processing (step S
6) The operation pattern determination means 26 selects in advance the operation pattern in the vicinity of each point defined for the welding line in each process up to this point. First, an operation pattern of an approach is selected for an end point serving as a welding start point. When selecting this operation pattern, the pattern is selected based on the positional relationship between the cross-sectional shape of the mounting member to be welded and the adjacent member. As for the touch sensing pattern at the welding start point, the pattern is selected in consideration of not only the cross-sectional shape of the mounting member and the positional relationship between the adjacent members but also the end shape of the mounting member. The end welding pattern at the welding start point is selected based on the end shape of the mounting member. If the welding start point is the point of occurrence of interference, the pattern is further selected in consideration of the presence of interfering members. Even when the welding start point is a region division point, a pattern that takes that fact into account is selected. Next, for the welding midpoint,
If it is a curvature intermediate point, a pattern for performing circular interpolation is selected. If it is an interference avoidance intermediate point, a pattern for changing the torch attitude is selected. Finally, an operation pattern is selected for the welding end point by performing the same processing as that for the welding start point.

Next, the robot data processing system of FIG. 5 performs the following processing. G. FIG. Robot Data Conversion Process (Step S7) The robot data conversion means extracts an operation program corresponding to the operation pattern from the operation pattern database based on the data, and based on the welding design information defined for the welding line, Assign welding conditions to the operation program.

H. Robot data transfer processing (step S
8) Since the operation program of the robot is generated by the above processing, it is converted into execution data of the robot as necessary, and the data is transferred to each robot control device 30. Through these series of processes, an operation program that can operate a plurality of robots is automatically generated, and the robots can operate.

The present invention can be applied not only to the manufacture of the bridge panel described above but also to a small assembly panel of a shipbuilding block.

[0031]

As described above, according to the present invention, in a welding robot system in which a plurality of robots perform welding on the same workpiece, the shape information of the workpiece including the positional information of the mounting member and the shape information of the mounting member are provided. As long as welding design information is available, operation data for multiple robots can be automatically generated without the intervention of an operator. Significant reduction can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a centralized management system showing one embodiment of the present invention.

FIG. 2 is a schematic diagram of a welding robot system in an embodiment.

FIG. 3 is an explanatory diagram of work information.

FIG. 4 is an explanatory diagram showing a processing flow and processing contents of the present system.

FIG. 5 is a flowchart of the entire system.

FIG. 6 is an explanatory diagram in a case where a curved welding line is generated.

FIG. 7 is an explanatory diagram showing details of an interference avoidance process;

FIG. 8 is an explanatory diagram showing the contents of an operation area dividing process.

FIG. 9 is a perspective view of a typical web panel.

FIG. 10 is a perspective view of a representative flange panel.

FIG. 11 is a front view showing an outline of an automatic web panel welding apparatus.

FIG. 12 is a front view showing an outline of an automatic welding device for a flange panel.

[Explanation of symbols]

 Reference Signs List 10 host computer 11 work information database 12 robot operation program automatic generation system 13 robot database 14 operation pattern database 15 welding condition database 16 robot data processing system 21 work information input means 22 welding line determination means 23 interference avoidance means 24 operation area division means 25 Welding sequence determining means 26 Operation pattern determining means 30 Robot controller 31 Mounting line (welding line) 32 Butt line 33 Welding line 35, 36 End point (welding start point / end point) 37 Curvature intermediate point 42 Interference occurrence point 43 Interference avoidance intermediate Point 44 Area dividing line 45, 46 Area dividing point 100 Web panel 101 Flange panel 123, 183 Welding robot

────────────────────────────────────────────────── ─── Continuing from the front page There is an application for the application of Article 30 (1) of the Patent Law. On November 18, 1992, the Welding Society of Japan Kansai Chapter hosted a "Technical Session for FY 1994" Trends in Welding Technology as a System ". Announced. Application for Patent Law Article 30, Paragraph 1 applied. On November 20, 1992, NKK Technical Report No. 141 “CAD / CAM Welding Robot System for Bridge Panels” issued by Nippon Kokan Co., Ltd. (p. 47-57) Announced. (58) Field surveyed (Int.Cl. ⁶ , DB name) G05B 19/4093 G05B 19/18

Claims (1)

(57) [Claims] 1. A workpiece is manufactured by a plurality of welding robots.
In welding robot system, the work information input means for inputting workpiece shape information and the workpiece weld design information, and weld line determining means for generating and determining a weld line in each mounting member on the basis of the input shape of the workpiece, the welding The interference between the robot and the workpiece is
Check using the cross-sectional shape of the work, and if there is interference
By changing the torch posture within a certain range
Avoidable interference avoidance point or unavoidable interference
Interference avoiding means for generating an occurrence point on the welding line; dividing the welding line into a plurality of robot operation regions;
And operating region dividing means for generating the split point to the welding line, a welding order determining means for determining the welding order of the weld line for each of the robot operation area, respectively operate for each weld points constituting the welding line An automatic generation system for a welding robot operation program, comprising: operation pattern determination means for determining a pattern.