CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a United States national stage application of International Application No. PCT/JP2018/007372, filed Feb. 27, 2018, which designates the United States, and claims priority to Japanese Patent Application No. 2017-054687, filed Mar. 21, 2017, and the entire contents of each of the above applications are hereby incorporated herein by reference in entirety.

TECHNICAL FIELD

The present invention relates to a method for acquiring weld pass information pertaining to a weld pass for welding at least two members to be welded, and a welding robot system.

BACKGROUND ART

Nowadays, robots are used in various fields of industry. Such industrial robots include a welding robot as a typical one. For a welding operation, optimal welding conditions have to be set according to each welding object, and a large number of elements, parameters, and combinations thereof are involved in the setting of the welding conditions. Among these, determination of a weld pass (weld line) for welding a member to be welded, which is a welding object, is an important matter.

PTL 1 discloses a weld line generation method for quickly extracting a weld line based on 3D CAD data constituted by many line segments including a weld line candidate. The weld line generation method includes a step in which a surface (a first surface), serving as a reference, between two surfaces of a member which forms a weld line is designated; a step in which the other surface (a second surface that is a groove surface) between the two surfaces of the member which forms the weld line is designated; a step in which a ridgeline is extracted; a step in which a weldable ridgeline section is selected; a step in which weldable ridgelines are integrated and weld line information is generated; and a step in which the weld line information is corrected according to a groove shape.

PTL 2 discloses a teaching system that facilitates teaching operation to a robot. The teaching system includes an image generation unit, a starting point designation unit, a via point designation unit, and a generation unit. The image generation unit generates a virtual image including a closed processing line set on a member to be welded, which is an object for processing by a robot. The starting point designation unit designates a starting point at a position other than the processing line on the virtual image. The via point designation unit designates a via point on the processing line. The generation unit generates teach data to a robot for a path following a processing line from a starting point via the via point and returning again to the via point.

CITATION LIST

Patent Literature

PTL 1: Japanese Unexamined Patent Application Publication No. 2010-184278PTL 2: Japanese Unexamined Patent Application Publication No. 2015-202523

SUMMARY OF INVENTION

Technical Problem

Meanwhile, in many cases, a problem arises in a welding operation at weld ends including one end of a member to be welded which is a welding object, and a starting point or an ending point of welding. Another member to be welded or another member may be present at one end of a member to be welded, and these objects may provide an obstruction to a welding operation. However, conventional art including the above-described patent literatures does not present a technique for grasping the situation of one end of a member to be welded in advance, and performing a smooth welding operation.

The present invention relates to a method for acquiring weld pass information and a welding robot system in consideration of information on an object which may interfere with a welding operation pertaining to one end of a member to be welded and a weld end.

Solution to Problem

The present invention provides a method for acquiring weld pass information pertaining to execution conditions for a weld pass for welding two members to be welded which are welding objects of a welding robot, the method including: a step in which a weld pass for welding the two members to be welded is extracted from 3D CAD data; a step in which a wall surface determination model having a predetermined 3D shape is prepared; a step in which the wall surface determination model is positioned in a direction extending towards the outside of the weld pass with a weld end serving as a reference, the weld end being at least one of a starting point and an ending point of the weld pass; and a step in which it is determined whether or not a wall surface interferes with the positioned wall surface determination model, the wall surface being demarcated by another member different from the two members to be welded.

The present invention provides a welding robot system including: a welding robot that welds a member to be welded; a computer that controls an operation of the welding robot in accordance with a predetermined operating program. The computer extracts a weld pass for welding two members to be welded from 3D CAD data; prepares a wall surface determination model having a predetermined 3D shape; positions the wall surface determination model in a direction extending towards the outside of the weld pass with a weld end serving as a reference, the weld end being at least one of a starting point and an ending point of the weld pass; determines whether or not a wall surface interferes with the positioned wall surface determination model, the wall surface being demarcated by another member different from the two members to be welded; and teaches the welding robot the acquired weld pass.

Advantageous Effects of Invention

According to the present invention, it is possible to determine whether or not there is interference of another member in the vicinity of a weld end of a weld pass, and particularly, to make a welding operation at one end of a member to be welded smooth.

