KR20200020496A - Method for recognizing absent welding bid of shipbuilding block - Google Patents

Abstract

The present invention relates to a method for recognizing a welding bead of a hold unit in a shipbuilding block. The method for recognizing a welding bead of a hold unit in a shipbuilding block comprises: a step (A) of setting a tool coordinate of a welding torch (15) by performing initialization of a controller (40) in a welding robot (10) arranged around a welding hold unit; a step (B) of setting a first alignment point by individually moving the welding torch (15) of the welding robot (10) to a bottom surface and a wall by the same distance; a step (C) of determining and storing a first reference point (P1) at a position in which the welding torch (15) is moved from the first alignment point in a Z-direction of a tool coordinate by predetermined distance; a step (D) of setting a second alignment point by repeating a motion of the step (B) at the position in which the welding torch (15) is moved from the first alignment point by predetermined distance; a step (E) of determining and storing a second reference point (P2) at the position in which the welding torch (15) is moved from the second alignment point by predetermined distance in the Z-direction of the tool coordinate; and a step (F) determining and storing a third reference point (P3) which is a start point of the welding bead from the stored first reference point (P1) and the second reference point (P2). According to the present invention, the method for recognizing a welding bead of a hold unit in a shipbuilding block does not require additional costs in comparison with an LDS method and can omit a calibration work. The method for recognizing a welding bead of a hold unit in a shipbuilding block also improves productivity and work efficiency by automatic welding by automatic recognition of a welding part which is held.

Description

Method for recognizing absent welding bid of shipbuilding block

The present invention relates to a welding method of a shipbuilding block, and more particularly, to a method of recognizing a welding bead welding part of the shipbuilding block for implementing automatic welding for the welded welded in the manufacturing process of the shipbuilding block.

In the block of shipbuilding process, welding holding parts are generated at various positions after automatic welding (carriage, V-Rod). Since these target parts are all finished by manual welding, there is a high possibility of deteriorating the working environment and causing musculoskeletal diseases of workers. It is urgent to introduce an automated process using a robot for welding of shipbuilding block holding parts.

As an example of the related art document related thereto, Korean Patent Publication No. 1714458 may include: detecting a bottom surface using a touch sensor mounted on a torch; Sensing the wall surface by performing a touch while retreating and advancing in the opposite direction; Measuring a distance by using a laser distance sensor spaced apart from the end of the welding torch; Automatically recognizing a welding holding part; And the like.

However, welding bead recognition with LDS requires relatively high calibration and frequent calibration to maintain accuracy.

In addition, if the calibration is good, the effect is good, but in order to improve the performance, because it can only be mounted close to the end of the torch may cause frequent failure due to heat during welding.

As another example of the prior art document, Korean Patent Publication No. 1844281 may include: a sensor sensing a two-dimensional scan method inside a complex structure; A primary feature point extractor that separates the spatial feature points and the obstacle information; A secondary feature point extraction unit for extracting a secondary feature point related to the corner portion; A workspace recognition unit for recognizing a workspace by detecting edges and faces of a complex structure; And the like.

However, since it is based on the 2D scanner, it is difficult to escape the calibration burden and it is relatively difficult to apply to the welding holding part of the shipbuilding block due to the relatively complicated operation.

Korean Patent Publication No. 1714458 "Welding hold position detection method using laser distance sensor" (published date: 2017.03.10.) Korean Patent Publication No. 1844281 "Wide-area Environment Recognition Method and System for Complex Structure Welding Automation" (Publication date: October 30, 2017)

An object of the present invention for improving the conventional problems as described above, shipbuilding block for performing a series of processing on the basis of the touch sensing that can be excluded in the calibration to recognize the welding holding portion generated in various positions in the block of the shipbuilding process The present invention provides a method for recognizing a weld bead in a reserved part.

In order to achieve the above object, the present invention provides a method for recognizing a weld bead in the welding holding portion of the ship block: (A) the tool coordinates of the welding torch through the initialization of the controller in the welding robot disposed near the welding holding portion Setting up; (B) setting a first alignment point by moving the welding torch of the welding robot to the bottom surface and the wall surface of the welding holding part by the same distance, respectively; (C) determining and storing the first reference point P1 at the position where the welding torch is moved by the distance set in the tool coordinate Z direction from the first alignment point; (D) repeating the operation of step (B) at the position where the welding torch is moved by the set distance from the first alignment point to set the second alignment point; (E) determining and storing the second reference point P2 at the position where the welding torch is moved by the distance set in the tool coordinate Z direction from the second alignment point; And (F) determining and storing the third reference point P3, which is the starting point of the welding bead, from the stored first reference point P1 and the second reference point P2.

As a detailed configuration of the present invention, the step (A) is characterized in that provided with a straightener on the welding torch of the welding robot to maintain the straightness of the wire serving as a touch sensor.

As a detailed configuration of the present invention, the step (B) is to move the welding torch in the vertical downward direction to touch the bottom surface, to move the vertical distance in the vertical upward direction, and to advance in the horizontal direction to touch the wall surface, horizontal The first alignment point is set by reversing the first distance in the direction.

As a detailed configuration of the present invention, the step (C) is characterized in that to maintain the posture of the welding torch in the 45 ㅀ direction with respect to the vertical and horizontal directions.

As a detailed configuration of the present invention, the step (F) is characterized in that the welding torch is moved in a linear direction formed by the first reference point (P1) and the second reference point (P2) while maintaining the on state of the touch sensor.

As described above, according to the present invention, there is no additional cost compared to the LDS method, and the calibration work can be omitted, and there is an effect of improving work efficiency and productivity by fully automatic welding by automatic recognition of the reserved welding part. .

1 is a schematic diagram of a welding robot for implementing the method according to the present invention.
Figure 2 is a schematic diagram showing the main part of the welding robot according to the present invention.
3 is a schematic conceptual diagram of the main steps of the method according to the invention;
4 is a flowchart showing the detailed steps of the method according to the invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention proposes a method for recognizing a weld bead in the welding holding portion of the shipbuilding block. The welding holding part, which occurs during the automatic welding process of shipbuilding blocks and is accompanied by manual welding, is not limited thereto. Recognition of the weld bead is based on the algorithm for automatic welding conversion of the manual welding part.

The algorithm of the present invention is carried out by a controller 40 mounted on the welding robot 10 of FIG. 1, which has a microcomputer circuit having a microprocessor, a memory, and an input / output interface.

Step (A) according to the present invention is a process of setting the tool coordinates of the welding torch 15 through the initialization of the controller 40 in the welding robot 10 disposed near the welding holding part. After the operator arranges the movable welding robot 10 in the welding holding part, the initialization is performed by the controller 40. In FIG. 1, x, y, and z are tool coordinates based on the welding torch 15, and x, y, and z are robot coordinates based on the welding robot 10. The welding torch 15 feeds the wire 25 for automatic welding, and the object contact of the wire 25 is sensed through the touch sensor 30.

As a detailed configuration of the present invention, the step (A) is a straightener 20 to the welding torch 15 of the welding robot 10 to maintain the straightness of the wire 25 serving as the touch sensor 30. It is characterized by including. The touch sensor 30 is a part that is narrowly mounted to the welding torch 15, but broadly includes a sensing circuit of the wire 25 and the controller 40. Referring to FIG. 2, a straightener 20 that maintains the straightness of the wire 25 constituting a part of the touch sensor 30 is illustrated.

The straightener 20 of FIG. 2 (a) is a clamp type 21, and presses the wire 25 using a pair of opposing jigs to induce straightening. The straightener 20 of FIG. 2 (b) is a roller type 22, in which a plurality of rollers are zigzag to face each other and induce straightening of the wire 25 passed therebetween. In any case, the bending of the wire 25 may be prevented during the operation of the touch sensor 30 to maintain the accuracy and reliability of the measurement.

Step (B) according to the present invention undergoes a process of setting a first alignment point by moving the welding torch 15 of the welding robot 10 to the bottom surface and the wall surface of the welding holding part by the same distance, respectively. 3A and 3B, the controller 40 performs the motion of the set pattern with respect to the welding torch 15 to set the position at which the tip of the wire 25 is aligned. The alignment point is divided into a first alignment point and a second alignment point corresponding to the first reference point P1 and the second reference point P2 described later.

As a detailed configuration of the present invention, the step (B) is to move the welding torch 15 in the vertical downward direction to touch the bottom surface, to move by the first distance in the vertical upward direction, to advance in the horizontal direction to touch the wall surface The first alignment point may be set by reversing the first distance in the horizontal direction. In FIG. 3 (a), the welding torch 15 reaches a position spaced apart from the first distance vertically (for example, 49.5 mm) and the second distance (for example 49.5 mm) from the wall surface. This is generated through the process of downward touch, 49.5 mm upward movement, forward touch, and 49.5 mm backward movement of the welding torch 15. Accordingly, the welding torch 15 may temporarily wait at the first alignment point spaced 70 mm to the intersection between the bottom surface and the wall surface.

Step (C) according to the present invention proceeds to the process of determining and storing the first reference point (P1) at the position where the welding torch 15 is moved by the distance set in the tool coordinate Z direction from the first alignment point. The direction from the first alignment point toward the intersection point of the bottom surface and the wall surface corresponds to the tool coordinate Z direction. In FIG. 3B, when the welding torch 15 moves 66 mm in the tool coordinate Z direction, the welding torch 15 reaches the first reference point P1 corresponding to the thickness of the welding bead. That is, when the welding torch 15 moves horizontally at a distance from the first reference point P1, the tip of the wire 25 contacts the welding bead of FIG. 3C.

As a detailed configuration of the present invention, the step (C) is characterized in that to maintain the posture of the welding torch 15 in the 45 ㅀ direction with respect to the vertical and horizontal directions. The controller 40 detects a posture with respect to the bottom and wall surfaces, and a posture according to the vertical and horizontal movement of the welding torch 15. Based on this information, the welding torch 15 can maintain its posture in the 45 ㅀ direction from the first alignment point to the intersection point. The 45 ㅀ attitude of the welding torch 15 should be maintained to increase the reliability of reaching the first reference point P1 at the first alignment point.

Step (D) according to the present invention undergoes a process of setting the second alignment point by repeating the operation of the step (B) at the position where the welding torch 15 is moved by the set distance from the first alignment point. FIG. 3C illustrates a state in which the welding torch 15 sets the second alignment point at a position where the welding torch 15 is horizontally moved at a distance (for example, 30 mm) set from the first alignment point. Of course, this is generated through the process of downward touch, 49.5 mm upward movement, forward touch, and 49.5 mm backward movement of the welding torch 15 as in step (B) described above. At this time, the controller 40 accumulates data of the work process and increases or decreases the set distance 30 mm.

Step (E) according to the present invention proceeds to a process of determining and storing the second reference point (P2) at the position where the welding torch 15 is moved by the distance set in the tool coordinate Z direction from the second alignment point. By moving 66 mm in the tool coordinate Z direction on the same principle as reaching the first alignment point in step (C), the second reference point P2 corresponding to the neck thickness of the weld bead is reached. That is, when the welding torch 15 moves horizontally at a distance from the second reference point P2, the tip of the wire 25 contacts the welding bead of FIG. 3C.

Step (F) according to the present invention goes through a process of determining and storing the third reference point (P3) that is the starting point of the weld bead from the stored first reference point (P1) and the second reference point (P2). The third reference point P3 of the welding bead shown in FIG. 3 (c) is generated in the process of moving the welding torch 15 from the first reference point P1 to the second reference point P2. As shown in FIGS. 3 and 4, the LDS method is not applied, and the calibration operation may be omitted.

As a detailed configuration of the present invention, the step (F) is to move the welding torch 15 in a linear direction formed by the first reference point (P1) and the second reference point (P2) while maintaining the on state of the touch sensor (30). It is characterized by. As described above, since the first reference point P1 and the second reference point P2 having a 30 mm interval are spaced apart from each other by the thickness of the weld bead at the intersection of the bottom surface and the wall surface, the welding torch 15 is moved to the first reference point P1. In the direction of the straight line passing through the second reference point (P2) in the tip of the wire 25 touches the weld bead. During the movement of the welding torch 15, the touch sensor 30 should be kept in an on state.

In this way, if the welding is automatically recognized and held, the fully automated concept can be implemented to improve work efficiency and productivity.

It is apparent to those skilled in the art that the present invention is not limited to the described embodiments and that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, such modifications or variations will have to belong to the claims of the present invention.

10: welding robot 15: welding torch
20: straightener 21: clamp type
22: roller type 25: wire
30: touch sensor 40: controller

Claims (5)

In the method of recognizing the weld bead in the welding hold of the shipbuilding block:
(A) setting tool coordinates of the welding torch 15 through initialization of the controller 40 in the welding robot 10 disposed near the welding holding part;
(B) setting a first alignment point by moving the welding torch 15 of the welding robot 10 to the bottom surface and the wall surface of the welding holding part by the same distance, respectively;
(C) determining and storing the first reference point P1 at the position where the welding torch 15 is moved by the distance set in the tool coordinate Z direction from the first alignment point;
(D) setting the second alignment point by repeating the operation of step (B) at the position where the welding torch 15 is moved by the set distance from the first alignment point;
(E) determining and storing the second reference point P2 at the position where the welding torch 15 is moved by the distance set in the tool coordinate Z direction from the second alignment point; And
(F) determining and storing the third reference point (P3) that is the starting point of the welding bead from the first reference point (P1) and the second reference point (P2) stored; welding the hold portion of the shipbuilding block comprising a Bead recognition method. The method according to claim 1,
The step (A) is characterized in that shipbuilding, characterized in that provided with a straightener 20 in the welding torch 15 of the welding robot 10 to maintain the straightness of the wire 25 serving as the touch sensor 30 Recognition method of welded bead of block The method according to claim 1,
In the step (B), the welding torch 15 is moved vertically downward to touch the bottom surface, vertically upwardly moved by the first distance, and moved horizontally to touch the wall surface, and the first horizontal direction. A method for recognizing a welded bead in a holding part of a ship block, characterized in that the first alignment point is set by reversing the distance. The method according to claim 1,
The step (C) is a weld bead recognition method of the holding block of the ship block, characterized in that to maintain the posture of the welding torch 15 in the 45 ㅀ direction to the vertical and horizontal directions. The method according to claim 1,
Step (F) of the shipbuilding block, characterized in that for moving the welding torch 15 in a linear direction formed by the first reference point (P1) and the second reference point (P2) while maintaining the on state of the touch sensor (30). Reservoir weld bead recognition method.

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