CN110625308A

CN110625308A - Welding robot-based rubber bridge support welding method

Info

Publication number: CN110625308A
Application number: CN201910921515.8A
Authority: CN
Inventors: 高俊山; 暴国庆; 邓立为
Original assignee: Harbin University of Science and Technology
Current assignee: Harbin University of Science and Technology
Priority date: 2019-09-27
Filing date: 2019-09-27
Publication date: 2019-12-31

Abstract

The invention discloses a welding method of a rubber bridge support based on a welding robot, which comprises the following steps: (A) before welding a rubber bridge support, detecting a welding seam of a working object by using a radar sensor, and converting data into a point form on a rectangular coordinate system; (B) generating a plane model by utilizing a RANSAC algorithm according to the distribution of each group of collected points; (C) calculating the sizes of the intersection point and the welding line of the rubber bridge support by using the plane model; (D) and transmitting the data to a welding robot controller to generate a program, and welding the rubber bridge support. The method can accurately track the welding seam of the rubber bridge bearing, does not need linkage of additional data, can minimize the intervention of workers, and can improve the productivity.

Description

Welding robot-based rubber bridge support welding method

Technical Field

The invention relates to the field of industrial welding robots, in particular to a welding method of a rubber bridge support based on a welding robot.

Background

With the gradual development of the robot technology, the robot is used for replacing the manual work in the industry, especially for the more important welding work. The welding work of a welding robot is usually performed by a work object at one time or repeated regularly, but since the shape, size, and type of a welding workpiece are different from each other, information on various objects must be provided to the robot when performing the welding work of the robot.

In the welding of the rubber bridge bearing, the materials and the sizes of the upper and lower bearing plates, the intermediate steel lining plate, the stainless steel plate and the rubber plate need to be considered, so that the data of the rubber bridge bearing is processed and then input into the robot, or a robot operator directly measures a target size and directly inputs the target size into the robot to generate a program for completing the operation, and the welding process has the problems of low efficiency, high danger, high cost and the like due to the intervention of a plurality of workers.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a welding method of a rubber bridge support based on a welding robot.

The purpose of the invention is realized by the following technical scheme: a welding method of a rubber bridge support based on a welding robot comprises the following steps:

(A) before welding a rubber bridge support, detecting a welding seam of a working object by using a radar sensor, and converting data into a point form on a rectangular coordinate system; the key set of coordinates (x, y, z) obtained during the attitude change of the radar sensor is converted into (u, v, w).

(B) The distribution of the collected data integration groups is homogenized, the coordinates are integrated in a cube space to simplify the data into one point, the data of each surface point is decomposed according to the direction component on the normal line, each point P of the data point group is taken as a standard to extract adjacent points, a normal processor generated by the P is normalized, and a plane model is generated according to the RANSAC algorithm.

(C) With the above planar models, the intersection point and the weld line are calculated with the generation of the intersection point of the three planar models, the oblique angle of the two planar models, and the intersection line of the two planar models as targets.

(D) And inputting the processed product into a welding robot controller to generate a program for completing the operation, and welding the rubber bridge bearing after the preparation work is completed.

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention adopts the radar sensor to detect the welding seam of the rubber bridge bearing, even if the welding point has more complicated shape, the welding point can be easily loaded on the robot, and a program capable of finishing the operation is generated.

(2) The invention does not need the linkage of additional data in the aspect of data processing, design and construction, and can minimize the intervention of workers, thereby achieving the effect of improving the productivity.

(3) The execution end of the welding robot can accurately track the welding seam of the rubber bridge support, avoid the damage of a rubber plate caused by the high temperature of a welding gun in the welding process and ensure the quality of the rubber bridge support.

Drawings

Fig. 1 shows a working system of a welding robot.

Fig. 2 is a diagram of relative positions of a radar sensor and a target.

Fig. 3 is a diagram of a RANSAC algorithm model.

Fig. 4 is a flow chart of the welding robot work.

Icon: 10-welding robot: 11-radar sensor: 12-rubber bridge bearing: 13-welding bench.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in FIG. 1, the present invention is provided with a radar sensor at the executing end of the welding robot in order to detect the welding line of the rubber bridge bearing. The welding robot adopts a kuka series and is of a multi-joint structure consisting of a plurality of 'combinations', wherein a welding gun can be replaced by gun heads of different types, and the position of the welding robot can be adjusted according to the working requirement. The basin-type rubber bridge support on the welding workbench consists of an upper support plate, a lower support plate, a middle steel lining plate, a stainless steel plate and a rubber plate.

The algorithm for weld trajectory tracking in the present invention is stored and executed in the controller of the welding robot.

The step (a) performed according to the present invention is a process of detecting a weld of the rubber bridge bearing and converting into rectangular coordinates, which is a process of obtaining weld data information using a welding robot.

The step (A) of the invention is to attach a radar sensor to the execution end of the welding robot, featuring the measurement. The method is that a radar sensor is arranged on a specific shaft of the robot, the values output by each unit of the rotation and the movement of the shaft and the sensor are stored, and the data can be converted into the data of a 3-dimensional rectangular coordinate system of the center of the robot by utilizing the joint angle value and the tool transformation of the robot.

While the radar sensor rotates on the robot executing end, the data of each point can be analyzed by using the coordinates of the angle and the distance appearing on the reference point P, and the size information of the welded workpiece is obtained, and at the moment, the point coordinates (x, y, z) obtained in the posture change process of the radar sensor can be converted into (u, v, w).

As shown in fig. 2, step (B) of the present invention is a process of forming a planar model by uniformizing the distribution of the above-described key point groups. From the relationship between these two coordinate systems, the polar coordinate system can be converted into a rectangular coordinate system, following the derivation process.

P′_xyz＝RP′_uvw+P

Therefore, it is

Wherein:

rotating the joint of the robot execution end;

theta is a horizontal included angle between the robot and the plane;

d is the horizontal distance between the robot and the rubber bridge support;

and L is the length between the robot and the rubber bridge support.

As shown in fig. 3, the average value of the coordinates is integrated in a set cubic space, data of each point is separated according to the orientation value after being simplified by one point, and a plane model is generated according to the RANSAC algorithm, so that the time required for subsequent operation can be reduced.

Step (C) of the present invention is a process of calculating an intersection point and a point line using the above plane model. Specifically, the intersection of the three plane models, the oblique angles of the two plane models, and the intersection line of the two plane models are used as characteristics. The start/end point information is generated from simultaneous equations of the three plane models. The angle on the normal of the two plane models yields information of the inclination of each plane. In both planar models, weld lines are generated by intersecting lines, and coordinate axes are also generated.

As shown in fig. 4, the process includes the first three steps of the present invention, and the last step (D) is to process the welding data obtained in the first three steps and input the processed welding data into the welding robot controller to generate a program capable of completing the operation of welding the bridge support, and then to debug the program, and to weld the rubber bridge support after the preparation operation is completed.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A welding method of a rubber bridge support based on a welding robot is characterized by comprising the following steps: the method comprises the following steps:

(A) before welding a rubber bridge support, detecting a welding seam of a working object by using a radar sensor, and converting data into a rectangular coordinate counting point form; the key set of coordinates (x, y, z) obtained during the attitude change of the radar sensor is converted into (u, v, w).

2. The welding robot-based rubber bridge support welding method of claim 1, characterized in that: and (A) detecting a welding line of the rubber bridge bearing which is a working object of the welding robot. The welding robot is characterized in that a radar sensor is arranged at the execution end of the welding robot.

3. The method of claim 2, wherein: according to the point coordinates obtained in the posture change process of the radar sensor, the data of each point can be analyzed, and the size information of the welded workpiece can be obtained.

4. The welding robot-based rubber bridge support welding method of claim 1, characterized in that: and (B) utilizing the coordinate average value of the set cubic space inner integral group, simplifying by using one point, separating the data of each point according to the azimuth value, generating a plane model according to the RANSAC algorithm, and detecting the welding line of the welding robot to the rubber bridge support.

5. The welding robot-based rubber bridge support welding method of claim 1, characterized in that: and (C) calculating the intersection point and the welding line of the rubber bridge support by taking the intersection point of the three plane models, the bevel angle of the two plane models and the intersection line of the two plane models as targets.