KR20100045155A - Method for setting position of lug welding robot using laser pointer - Google Patents

Abstract

PURPOSE: A method for setting the position of a lug welding robot using a laser pointer is provided to remove the risk of malfunctions due to dust or sparks and to eliminate the need for image processing. CONSTITUTION: A method for setting the position of a lug welding robot using a laser pointer is as follows. Additional five axes enabling the X-, Y-, and Z-axial movement and X- and Y-directional tilting of the welding robot are installed on a welding robot carriage(10). Two pairs of linear laser pointers are installed opposite each other. The distance to a lug and the interval and parallelism of four laser beams are determined from an image formed on a block bottom(2) to which the lug(1) is welded. An error in the location and posture of the robot is determined. The welding robot carriage and the additional five axes are manually operated to set the location and posture of the lug and the carriage.

Description

How to set position and posture of lug welding robot using laser pointer {METHOD FOR SETTING POSITION OF LUG WELDING ROBOT USING LASER POINTER}

The present invention relates to a method for setting the position and posture of a lug welding robot by using a bogie equipped with an additional additional axis and four laser pointers for welding a welding object (lug) located on the upper part of the robot.

In general, in the shipbuilding process, steel structure blocks are supported by block supports, and overhead welding is frequently performed to attach lugs or other various attachments to the bottom of the blocks. When a person performs such overhead welding, there are various problems. Recently, a welding-only robot has been applied, and various types of trolleys have been proposed to improve the mobility of the robot drive.

When welding lugs using such a welding robot, the position and posture of the robot should be corrected. The lug should be attached by welding under the block supported by the truss (block support). The flatness of the bottom of the block to which the lug is attached varies slightly depending on the position of the lug, and the site bottom is also slightly inclined. Therefore, the posture of the robot performing overhead welding should be corrected according to the attachment position (X, Y, Z) and posture (ROLL, PITCH, YAW) of each lug.

As a method for correcting the position and attitude of the welding robot, a method using a laser vision sensor and a method using a laser pointer are known.

The laser vision sensor uses a three-dimensional information (distance, angle) of the lug and corrects the position and posture of the robot accordingly. After properly positioning the trolley on which the welding robot is mounted, the 3D (X, Y, Z, ROLL, PITCH, YAW) information about the lug attachment position is obtained by using the laser vision sensor and the information is transferred to the robot controller. This is how the robot knows the position and angle of the lugs.

The method of using the laser pointer is to grasp the position information of the lug and determine the position of the robot. The position of the robot on which the welding robot is mounted is properly positioned near the lug, and then the position of the robot relative to the lug attachment position using the laser pointer. It is a way to correct.

By the way, the laser vision sensor using the above-described method, which enables precise position and attitude control, has the disadvantage that the price is very expensive, the development period is long, and high technology image processing technology is required. This allows precise position control but has the disadvantage that it is not possible to set the robot's relative posture to the lug.

For good weld quality in overhead (O / H) lug welding, the relative position and posture between the robot and the workpiece must be ensured at a much more precise level than for normal bottom welding. The yard of the shipyard is rugged because of the various tools and wires, and the block is also tilted because it is placed after the antagon on the trestle. Therefore, it is very difficult to set the relative position and posture between the robot and the work object which are required for the overhead welding (overhead welding).

In view of the above problems, an object of the present invention is to use a pair of four-line laser pointers to precisely correct the position and posture of a robot required for overhead (O / H) lug welding. It is to provide a method for setting the position and attitude of the lug welding robot using a laser pointer.

The position and posture setting method of the lug welding robot according to the present invention is provided on the welding robot trolley by providing an additional five axes which allow the welding robot to move in the X, Y, Z axis direction and the X, Y direction tilting. Two pairs of laser pointers face each other, and the position of the robot is determined by determining the distance to the lugs, the distance between the four laser lines, and the parallelism by the image (laser segment) of the laser pointer generated on the bottom surface of the block to which the lug is welded. And grasp the error of the posture, and the operator manually sets the position and posture between the lug and the trolley by manually operating the welding robot bogie and the additional five axes (3-translation axis, 2-rotation axis).

The present invention has a block bottom on which a lug is installed, and an additional five axes are provided with X, Y, Z slide means and X, Y tilting means for moving the welding robot in a five axis direction on a truck on which the welding robot is mounted. Adding the balance to the surface based on the four laser lines scanned on the bottom surface of the block by installing the first and third laser pointers in the X-axis and the second and fourth laser pointers in the Y-axis in order to scan the line type laser on the surface. Control the axis to compensate for position and attitude,

A first step of correcting the X and Y distances by determining the relative positions of the lug and the bogie by moving the bogies in the X and Y axis directions by identifying the relative positions of the lug and the bogie through the four line segments generated on the bottom surface of the block by the four laser pointers;

A second step of vertically sliding the welding robot such that four laser line segments meet at one point using the Z-axis slide function of the bogie after correcting the X and Y distances by the first step;

A third step of matching two longitudinal line segments out of four laser lines using a Y-tilting function after completion of the second step;

A fourth step of controlling two lateral line segments to be parallel by using an X-tilting function in a state in which the two longitudinal line segments coincide;

  In the fourth step, it is achieved by performing the fifth step of setting the position and posture between the lug and the balance by controlling the four line segments to meet at one point using the Z-axis slide while the same direction segments are parallel. .

In addition, the present invention is set during the posture error correction by moving the welding robot by using the X, Y slide function so that the intersection point made by the laser pointer coincides with the lug welding start point after setting the additional five axes of the bogie to maintain the fifth step. And a sixth step of correcting the position error again.

According to the present invention, at least the parallelism between the bottom surface of the block and the welding robot base surface is maintained within ± 0.5 ° and the position error is set to about ± 1mm.

The present invention makes it possible to correct the relative position and posture between the welding robot and the workpiece by using only four laser pointers at a very precise level (within a distance error of ± 1 mm and within a posture error of ± 0.5 °).

In addition, the method using the laser pointer of the present invention is economical compared to the conventional method because it does not require a high-tech image processing technology and use expensive equipment such as a laser vision sensor.

It also has the advantage that there is little risk of malfunction due to dust or sparks.

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

1 is a side view of the robot bogie for setting the position and attitude of the lug welding robot using the laser pointer according to the present invention, Figure 2 is a robot bogie for the position and attitude setting of the lug welding robot using the laser pointer according to the present invention This is an explanatory diagram of the configuration and degrees of freedom.

As shown therein,

Welding robot system for applying the present invention, equipped with a welding robot, and equipped with a two-axis travel and four-axis steering function bogie 10 capable of X, Y direction movement and YAW angle adjustment; A welding robot 40 mounted on an upper portion of the trolley 10; An additional 5-axis means is installed by X, Y, Z slide means and X, Y tilting means installed on the bogie 10 to move the base 30 of the welding robot 40 in the 5-axis direction. The first and third laser pointers and the second and fourth laser pointers 100 in the Y-axis direction are installed to scan the line-type laser on the block bottom surface 2 where the lugs 1 are installed. The balance controller 20 and the robot controller 50 are configured to be mounted on the upper portion of the balance 10.

The four laser pointers 100 are all line-type and two pairs face each other, and the image (laser line segment) of the laser pointer generated on the bottom surface of the block 2 is well sperm before the error is corrected. It's a form of installation. The spacing and parallelism of the four lines constituting the well sperm indicate errors in the position and attitude of the robot. Therefore, to see this will be set by correcting the position and attitude of the bogie.

This configuration is a means for sliding the welding robot 40 in the X, Y, Z-axis direction and tilting in the X, Y direction to the trolley 10 equipped with two-axis traveling and four-axis steering function to apply the present invention It comprises a means for making, four line-type laser pointer 100 is installed and configured, the two-axis driving and four-axis steering angle adjustment means, X, Y, It is configured to control the position of the lug and the balance and the attitude by controlling the Z slide means and the X, Y tilting means.

That is, the user sees the laser line segment projected by the four laser pointers and moves the bogie in the X and Y directions, as well as slide control in the X (Tx), Y (Ty) and Z (Tz) directions, and X (Rx). The position and attitude control between the lug 1 and the trolley 10 is controlled by tilting control in the Y (Ry) direction.

3 to 7 are explanatory views of the position and attitude setting method of the lug welding robot using the laser pointer according to the present invention.

First, as shown in FIG. 3, the relative position of the lug 1 and the bogie 10 is determined by the four line segments generated on the bottom surface of the block 2 by the four laser pointers 100. A first step of correcting the X and Y distance by moving in the X and Y axis directions is performed.

The four laser pointers 100 are each provided with two pairs of two X-axis direction line types (first and third laser pointers) and two Y-axis direction line types (second and fourth laser pointers). The laser line is projected on the bottom surface of the block 2 so that the user sees it and adjusts the distance and position of the lug 1 and the bogie 10. That is, the distance between the laser line segment by the first laser pointer and the lug 1 is moved, and the bogie 10 is moved in the X-axis direction to correct the distance with respect to the X axis, and then the laser line segment by the second laser pointer and By looking at the distance between the lugs 1, the trolley 10 is moved in the Y-axis direction to correct distance for the Y-axis.

Subsequently, as shown in FIG. 4, after the X and Y distances are corrected by the first step, the welding robot 40 meets four laser line segments at one point by using the Z axis slide function among the additional five axes of the bogie 10. Step 2 is performed to slide up and down.

After completion of the second step, as shown in FIG. 5, a third step of matching two longitudinal line segments among the four laser lines is performed using the Y-tilting function. The state shown in FIG. 5 adjusts the Y tilting function so that the two longitudinal segments are not in coincident form.

In the third step, in the state in which the two longitudinal segments are coincident with each other, as shown in FIG. 6, a fourth step of controlling the two horizontal segments to be parallel by using the X-tilting function is performed. At this time, if two transverse segments are made parallel, two coincident longitudinal segments are slightly opened, and parallelism is maintained.

  As shown in FIG. 7 in the state in which the same direction segments are parallel in the fourth step, using the Z-axis slide, the fourth segment is controlled to meet at one point to set the position and attitude between the lug and the balance. Perform the steps.

In this way, the distance between the line segment and the lug generated by the four laser pointers and the four line segments adjusts the balance and the additional five axes to set the position and attitude between the lug and the balance.

When the intersection point generated in the fifth step coincides with the lug welding start point, the lug welding may be performed by setting the current state.

If the additional five axes of the bogie are set to maintain the fifth step, the welding robot is moved by using the X and Y slide functions so that the intersection point made by the laser pointer coincides with the start point of the lug welding. After further performing the sixth step of recalibration, the welding preparation is completed.

In the present invention, the parallelism between the block bottom surface and the welding robot base surface is maintained within ± 0.5 ° and the positional error is set to ± 1mm.

According to the present invention, only the four laser pointers can be used to easily grasp the relative position and posture of the robot and the lug from the posture required for the work with the naked eye.

All four laser pointers are line type, with two pairs facing each other, and the image of the laser pointer created on the bottom of the block is well sperm-shaped before the error is corrected. The spacing and parallelism of the four lines constituting the well sperm indicate errors in the position and attitude of the robot. The detected error can be overcome by the operator by manually manipulating the welding robot bogie and the additional 5 axes (3-translation axis, 2-rotation axis) .When all errors are overcome, the laser pointer image is formed in the shape of cross. With the naked eye, the posture and position error can be easily identified.

If the relative distance and angle of the robot and lug are not the same as the value set in the welding condition, it will lead to poor welding, so the accuracy of the robot setting is very important, and considering the productivity, the importance of the setting speed cannot be overlooked. In this situation of shipyard, the advantages of precision and simple operation of this technique are met.

1 is a side view of a robot bogie for setting position and posture of a lug welding robot using a laser pointer according to the present invention;

Figure 2 is a view of the configuration and degrees of freedom of the robot bogie for setting the position and attitude of the lug welding robot using the laser pointer according to the present invention.

3 to 7 are explanatory diagrams for setting the position and attitude of the lug welding robot using the laser pointer according to the present invention.

<Description of the symbols for the main parts of the drawings>

1: lug 2: block bottom

10: balance 20: balance controller

30: welding robot base 40: welding robot

50: robot controller 100: laser pointer

Claims (4)

In the position and posture setting method of the lug welding robot, On the welding robot trolley, an additional five axes are installed to allow the welding robot to move in the X, Y, and Z directions and to tilt in the X and Y directions, and two pairs of line type laser pointers face each other. The distance to the lug, the spacing and the parallelism of the four laser segments are determined by the image (laser segment) of the laser pointer generated at the bottom of the block where the lug is welded to determine the error of the position and posture of the robot, and the operator welds Method for setting the position and attitude of the lug welding robot, characterized in that the position and posture between the lug and the bogie is set by manual operation of the robot bogie and the additional five axes (3-translation axis, 2-rotation axis). In the position and posture setting method of the lug welding robot, X, Y, Z slide means and X, Y tilting means for moving the welding robot in the 5-axis direction on the truck on which the welding robot is mounted, and additional 5-axis are provided, and the line type is provided on the bottom surface of the block where the lug is installed. The first and third laser pointers in the X-axis direction and the second and fourth laser pointers in the Y-axis direction are installed to scan the laser, and the additional five axes of the bogie are controlled based on four laser lines scanned on the bottom surface of the block. And posture, A first step of grasping the relative positions of the lug and the bogie by the four line segments generated at the bottom surface of the block by the four laser pointers and moving them in the X and Y axis directions to correct the X and Y distances; A second step of sliding the welding robot up and down so that four laser line segments meet at one point using the Z-axis slide function of the bogie after the X and Y distance corrections by the first step; A third step of matching two longitudinal line segments out of four laser lines using a Y-tilting function after completion of the second step; A fourth step of controlling two lateral line segments to be parallel by using an X-tilting function in a state in which the two longitudinal line segments coincide;   In the fourth step, a fifth step of setting the position and posture between the lug and the balance is performed by controlling the four line segments to meet at one point by using the Z-axis slide while the same direction segments are parallel to each other. How to set position and posture of lug welding robot. The method of claim 2, After setting the additional five axes of the bogie to maintain the fifth step, the welding robot is moved by using the X and Y slide functions so that the intersection point made by the laser pointer coincides with the lug welding start point, and again corrects the misaligned position error during posture error correction. Positioning and posture setting method of the lug welding robot, characterized in that it further comprises a sixth step. The method of claim 2, wherein the parallelism between the bottom surface of the block and the welding robot base surface is maintained within ± 0.5 °, and the position error is set within ± 1 mm.

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