JPH06214625A - Automatic generation system for operation program of welding robot - Google Patents

Abstract

PURPOSE:To reduce the teaching job for generation of a program when plural welding robots are sued for a single work. CONSTITUTION:A robot operation program is automatically generated based on only the work shape information and the welding design information. That is, two welding lines having both end points respectively are generated from the attachment lines based on the work shape supplied from a welding line deciding means 22. An interference avoiding means 23 checks the interference between the welding lines and the work to generate an interference avoiding point and an interference occurrence point. Then an operating area dividing means 24 divides the welding lines into plural robot operating areas, and a welding order deciding means 25 decides the welding order each operating area. Then an operating pattern deciding means 26 decides the operating patterns to all welding points on the welding lines. Thus an operation program of a welding robot is automatically generated based on those robot information and the robot is actuated.

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 perform work on one work, and particularly to a bridge panel by a teachingless CAD / CAM system. The present invention relates to an automatic generation system for a welding robot operation program that enables automatic welding of a welding robot.

[0002]

2. Description of the Related Art Teaching work of a work program for an industrial robot such as a welding robot has conventionally been performed by teaching its operation to a robot on a production line. In recent years, instead of such a teaching method, an off-line teaching system has been developed which can teach the robot at a place different from the production line (Japanese Patent Laid-Open No. 62-62).
108314, JP-A-2-262986, JP-A-3
-109608, etc.), the operation rate of the robot can be improved and teaching work can be simplified.

[0003]

However, even in the above-mentioned offline teaching system, it is common for the operator to perform some work while heading to the CRT. In this method, the intervention of the operator is indispensable, which saves labor. It is one of the factors that hinder the change. Further, in the case where a plurality of robots operate for one work, the offline teaching system itself cannot be applied at present. The above-mentioned JP-A-62
Even in the case of the technique disclosed in Japanese Patent Laid-Open No. 108314, the motion areas of the robots for one work are determined so as not to overlap with 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 production of bridge panels, the work time in the production design process is enormous with the conventional general offline teaching system. And is virtually unusable.

In view of the above situation, it is an object of the present invention to provide an automatic generation system for a welding robot operation program capable of achieving a significant labor saving in teaching work.

[0006]

SUMMARY OF THE INVENTION According to the present invention, when a plurality of welding robots perform work on one work, the operation program of the welding robot is used by using only the work shape information and the welding design information. The above problem is solved by using a system for automatically generating. That is, the configuration that characterizes the present invention is a work information input means for inputting work shape information and welding design information, a welding line determination means for determining a welding line based on the input work shape, and the welding. Interference avoidance means for checking the interference between the welding line and the work and avoiding the interference between the welding robot and the work, operation area dividing means for dividing the welding line into a plurality of robot operation areas, and each robot operation area Welding sequence determining means for determining the operation sequence of the welding line,
And a motion pattern determining means for determining a motion pattern with respect to a welding point forming the welding line.

Here, the work shape information is geometric information of the target work, and more specifically, the outer shape of the panel, the position information of the mounting line of the mounting member, the shape / 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 butt 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,
Welding design conditions such as fillet leg length and groove shape. It is assumed that these pieces of information are defined in the CAD system.

[0008]

In this automatic welding system, the shape information of the work is taken in and the work is placed at an appropriate position in the operation area of the welding robot. Then, based on the work attachment line information, both end points serving as the welding start point and welding end point of the welding line are defined. In addition, at the intersection of the welding lines, the robot shape data pre-defined as a welding robot model and the shape information of the mounting member of the shape information of the work are used to check the interference between the robot and the work, and the interference is detected. When it occurs, a point for avoiding interference is newly defined in the interference part. With respect to the welding line constituted by the above points, it is checked whether or not it is within the operation range of the robot, and which robot welds which welding line. Here, with respect to a welding line that extends over a plurality of robots, two points are newly defined at the intersection of the boundary line and the welding line in order to divide the welding line in each operation range. By this processing, all welding lines are assigned to each robot.

Next, the welding sequence of each robot is defined so that the dead time is minimized. Further, at each point of the welding line, the optimum operation pattern is selected using the attribute information indicating what kind of point the point is, and the geometrical attribute information at that point. Using the robot information generated by the above processing, a robot operation program can be automatically generated and a plurality of robots can be operated.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings in the case of a bridge panel.

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

In FIG. 1, 10 is a host computer consisting of a CAD / CAM system, 1 is a web line control computer, 2 is a flange line control computer, and 3 is 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, 6 is a drilling device 14
0 FA computer. In addition, the plate line joining device 160, the tacking device 170, and the welding device 18 are also attached to the flange line.
0, distortion removing device 190, drilling device 200, finishing device 2
10 are arranged, and these devices are sequence-controlled by the flange line controller 7.
Reference numeral 8 is an FA computer of the welding device 180, and 9 is an FA computer of the drilling device 200.

The information that is 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 the monitoring of operating conditions. In addition,
Here, an automatic generation system of an operation program for operating the welding robot system will be mainly described.

(2) Target Panel First, typical configuration examples of a web panel and a flange panel which are the target works of the present invention are shown in FIGS. 9 and 10, respectively. The standard panel size for both panels is 3 m wide and 12 m long. As shown in FIG. 9, the web panel 100 is formed by attaching a plurality of vertical stiffeners 103 and horizontal stiffeners 104 to a web plate 102 in the vertical and horizontal directions, and the end portions of the respective stiffeners are rotated and welded. The flange panel 101 includes a flange plate 10 as shown in FIG.
Since a plurality of vertical ribs 106 are attached in the lengthwise direction of 5, the welding line may become discontinuous at the drain hole, the diaphragm attachment position, or the like.

(3) Automatic Welding Device for Web Panels FIG. 11 shows an outline of an automatic welding device 120 for web panels. The automatic welding apparatus 120 includes a gate-shaped fixed frame 12
1 is a multi-joint welding robot 123 having a transverse shaft 122 as an external shaft, which is installed in a ceiling-suspended position in the length direction of the web plate at eight units at intervals of 2 m. This welding robot 123 has a known high-speed rotating arc welding torch 124 attached to the arm tip of a 6-axis articulated robot, and has a welding line automatic copying function by an arc sensor, a member end detecting function, and a bead joint detecting function. I have it. Then, each robot 123 simultaneously welds the 2 m pitch shared region, so that the welding work time can be made substantially constant regardless of the size of the panel. Further, between adjacent robots, collisions between the robots are avoided by optimizing a welding sequence and a robot interference checking function described later.

(4) Flange Panel Automatic Welding Device FIG. 12 shows an outline of the flange panel automatic welding device 180. The automatic welding device 180 is provided with a traveling gantry 181.
Three traverse shafts 182 are provided on the top as external shafts, and each of the traverse shafts 182 is provided with two articulated welding robots 183 having the same configuration as the robot 123 in a suspended state. To weld the vertical ribs 106, two welding robots 183 on each transverse axis simultaneously weld the both sides of the vertical ribs 106 with the welding torches 184 facing each other, and weld three vertical ribs 106 in one gantry run. can do.
Further, each of the robots 183 can individually extinguish and re-ignite an arc with respect to a weld line discontinuous portion such as a drain hole or a diaphragm mounting position, and intermittent welding can be performed during traveling at a constant speed gantry. .

(5) Teachingless CAD / CAM system FIG. 2 is a teachingless CAD / CA system for automatically generating operation data of the welding robot in the welding system shown in FIG.
It shows an outline of the 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 that takes out the work information and automatically generates a robot operation program. A robot database 13 stores the generated robot operation program. The generated program is an operation pattern, position information, and welding information arranged in order of operation. 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 the robot data,
The FA computer 5 or 8 retrieves necessary information from the operation pattern database 14 and the welding condition database 15, the robot data processing system 16 converts the information into robot operation data, and transfers the data to the welding robots 123 and 183.

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

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

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

B. Welding Line Determining Process (Step S2) Next, the welding line determining means 22 extracts the position information of the attachment line from the work information and defines the welding line. The mounting line is generally defined by one line, and the mounting line 31 is located at a position separated from the mounting line by the plate thickness of the mounting member.
A line 33 is generated in parallel with, 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 is defined, and points 35 and 3 are provided at both ends of each welding line.
6 is generated. The 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 also generated at a position where the line segment is divided as shown in FIG. This point 37 is defined as the midpoint of curvature.

C. Interference Avoidance Process (Step S3) The interference avoidance means 23 for avoiding interference between the work and the robot first checks the interference between the attachment member to be welded and the robot. When the target member is a shaped steel or the like, it may not be possible to adopt a weldable torch posture. Therefore, first, the interference is checked in a standard welding posture (for example, a torch angle of 45 °), and in the case of interference, the torch posture is changed within a specific range. This range is an attitude range in which welding quality can be maintained. FIG. 7A shows a method of checking interference by changing the torch posture. If the interference cannot be avoided due to the change in the torch posture, it is excluded from the robot welding target as a welding line that cannot be welded. The above is the interference avoidance processing between the attachment member to be welded and the robot.

Next, an interference check is performed between the robot and the mounting member that is close to the target member. First, a part that may cause interference is obtained. For one thing, the intersection of the welding lines is calculated for all the welding lines. This is because interference easily occurs at the intersection of two welding lines. Further, interference easily occurs even when the welding line and the welding line are close to each other.
As shown in (B) of FIG. 7, this distance generates line segments 37 and 38 parallel to the welding line 33 at a position separated from the one welding line 33 by a certain distance, and the line segment is the other line segment. 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. The interference between the welding robot and the workpiece is checked at each of the points 42 and 43 thus obtained. When interference occurs, the torch posture at that position is changed to check whether the interference can be avoided. When the interference can be avoided, that point is defined as the interference avoidance intermediate point 43. However, since the torch posture has a restriction on welding, it can be changed only within a specific range. If the interference cannot be avoided even if the torch posture is changed, a point is moved along the welding line to a position where the interference does not occur, and the point is defined as the interference occurrence point 42. Since the welding must be discontinuous at this interference generation point 42, the original welding line causes a welding residue due to this interference generation point.

D. Motion Region Dividing Process (Step S4) The motion region dividing means 24 assigns each welding line to a plurality of robots. Here, it is premised that a plurality of welding robots are arranged adjacent to each other and a plurality of robots perform welding of a target work. Specifically, a welding line within the operating range of a specific robot is defined as the welding line of that robot. However, one welding line may span the operating range of multiple robots.
For example, as shown in FIG. 8, it is a case where the horizontal welding lines 31 and 33 straddle the operation range of a plurality of robots. In this case, since one robot cannot continuously weld, the welding lines 31 and 33 are divided. As processing, welding line 3
Points 45 and 46 are generated at the intersections of 1 and 33 and the boundary line (region dividing line) 44 of the region, and the points 45 and 46 are defined as the region dividing points. Further, when one welding line 47 completely enters the region of a plurality of welding lines and welding can be performed by either robot, welding is performed by a robot having a small total welding length for the purpose of leveling the work.

E. Welding Order Determining Process (Step S5) The welding order determining means 25 defines the welding order of welding lines within the robot motion range. Basically, select the order that minimizes the air cut time,
In a welding system in which a plurality of robots are adjacent to each other, the avoidance of interference between the robots must be a top priority. Here, for the purpose of avoiding interference, an interference area having a risk of interference is set at the boundary of the operation area. For robots adjacent to the left and right robots, interference areas are provided on the left and right sides of the robot. The welding sequence is as follows: the welding line in the left interference region, the welding line in the center-free region, and the welding line in the right interference region. Specifically, first, the welding order of the welding line group including a part of the welding line in the interference range on the left side is defined. After that, the welding sequence in the weld line group of the central portion 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 for the region-divided welding line, the welding direction is always defined from left to right due to restrictions on bead lap welding. In such a process, mutual interference between robots can be minimized, but it cannot be completely avoided. Therefore, the above 3
Interlocking of the robots is done in one part, and the interference of the robots is avoided as a control function of the robots. Specifically, avoid the interference by taking an interlock so that the robot on the right side will not start welding on the left interference area until the welding line within the interference area on the left side of the robot is completed. ing.

F. Operation pattern determination process (step S
6) The motion pattern determining means 26 selects, in advance, a motion pattern in the vicinity of each of the points defined for the welding line in each process up to this point. First, an approach operation pattern is selected for the end point that is the welding start point. When selecting this operation pattern, the pattern is selected based on the positional relationship between the cross-sectional shape of the attachment 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 the positional relationship between the cross-sectional shape of the mounting member and the adjacent member, as well as 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. When the welding start point is the interference occurrence point, the pattern is selected in consideration of the fact that there is an interfering member. Even when the welding start point is the area dividing point, a pattern that takes this into consideration is selected. Next, for the welding midpoint,
If it is the middle point of curvature, a pattern for performing circular interpolation is selected. If it is the interference avoidance intermediate point, a pattern for changing the torch posture is selected. Finally, with respect to the welding end point, the operation pattern is selected by performing the same processing as the welding start point.

Next, the robot data processing system of FIG. 5 performs the following processing. G. Robot data conversion processing (step S7) In the robot data conversion means, an operation program corresponding to the operation pattern is retrieved from the operation pattern database based on the data, and based on the welding design information defined in the welding line, Allocate welding conditions to the operation program.

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

The present invention can be applied not only to the above-described bridge panel fabrication but also to a subassembly panel of a shipbuilding block or the like.

[0031]

As described above, according to the present invention, in a welding robot system in which a plurality of robots weld the same work, the shape information of the work including the position information of the mounting member and the mounting member are attached. As long as there is welding design information, it is possible to automatically generate motion data for multiple robots without the intervention of an operator. When operating a welding robot system for high-mix low-volume parts, teaching work can be performed. Significant reduction can be achieved.

[Brief description of drawings]

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

FIG. 2 is a schematic diagram of a welding robot system according to 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 when a curved welding line is generated.

FIG. 7 is an explanatory diagram showing the content of interference avoidance processing.

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

FIG. 9 is a perspective view of a representative 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 welding device for a web panel.

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

[Explanation of symbols]

 10 Host Computer 11 Work Information Database 12 Robot Motion Program Automatic Generation System 13 Robot Database 14 Motion Pattern Database 15 Welding Condition Database 16 Robot Data Processing System 21 Work Information Input Means 22 Welding Line Determining Means 23 Interference Avoiding Means 24 Motion Area Dividing Means 25 Welding sequence determining means 26 Motion pattern determining means 30 Robot controller 31 Attachment 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

Claims (1)

[Claims] 1. A work information input means for inputting work shape information and work welding design information, a weld line determination means for determining a weld line based on the input work shape, and an interference between the weld line and the work. An interference avoiding means for checking and avoiding interference between the welding robot and the work, an operation area dividing means for dividing the welding line into a plurality of robot operation areas, and an operation sequence of the welding line is determined for each robot operating area. A welding robot operation program automatic generation system, comprising: a welding sequence determining means for performing the operation; and an operation pattern determining means for determining an operation pattern with respect to a welding point forming the welding line.