scholarly journals A Vision-Based Robotic Laser Welding System for Insulated Mugs with Fuzzy Seam Tracking Control

Symmetry ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1385 ◽  
Author(s):  
Zaojun Fang ◽  
Wenwu Weng ◽  
Weijun Wang ◽  
Chi Zhang ◽  
Guilin Yang
Keyword(s):  
Laser Welding ◽  
Control Method ◽  
Tracking System ◽  
Welding Process ◽  
Reconstruction Algorithm ◽  
Seam Tracking ◽  
Least Square ◽  
Vacuum Degree ◽  
Logic Control ◽  
Sample Points

The symmetrical insulated mug is composed of two layers. The two ends of the two layers form the mouth and bottom seams of the insulated mug. The weld quality of the two seams is very important to keep the vacuum degree of the air between the two layers, which is vital for the heat-insulating property of the mug. Due to the narrow seam, laser welding is used. Since laser welding has high demand on the relative position of the seam and the laser torch, a vision-based seam tracking system is designed. Before welding is started, the vision sensor scans the seam and feature sample points are collected. A reconstruction algorithm is proposed to form the image containing the seam. Then, a least square fitting (LSF) method combined with random sample consensus (RANSAC) method is proposed to detect the smooth seam from the sample points. In the welding process, a seam tracking system with fuzzy logic control method is presented to keep the torch precisely on the seam. Finally, full experiments are conducted in the welding factory of the insulated mugs to verify the effectiveness of the proposed system and method.

Robot Based Laser Welding Technology

2008 ◽  
Vol 580-582 ◽  
pp. 565-568 ◽  
Author(s):  
Hee Shin Kang ◽  
Jeong Suh ◽  
Taik Dong Cho
Keyword(s):  
Laser Welding ◽  
Tracking System ◽  
Welding Process ◽  
Seam Tracking ◽  
Welding Quality ◽  
Monitoring Method ◽  
Welding Technology ◽  
Non Linear ◽  
Tailored Blank ◽  
Welding System

In order to obtain a good result in the laser welding process, the laser welding technology for manufacturing an automobile body is studied in this research. The monitoring of the welding quality and the seam tracking are studied to improve the productivity. The robot, the seam tracking system and CW Nd:YAG laser are used for the robot laser welding system. The laser system is 4kW Nd:YAG laser_(HL4006D) of Trumpf and the robot system is IRB6400R of ABB. The robot laser welding system is equipped with the seam tracker and plasma sensor. The seam tracking system is composed of SMART-20LS and RAPAL of Servo-Robot and MVS-5 sensor of MVS. The precise positioning of the laser beam on the joint to be assembled is obtained by seam tracker. The welding joints of steel plate are butt and lap joint. The three dimensional welding for non-linear tailored blank is performed after the fundamental experiments of bead-on-plate. Finally, the welding process for non-linear tailored blank and front side member is studied. The monitoring method of welding quality and seam tracking along the butt-joint are studied. The artificial defects in joint are well observed by the plasma intensity signal from the plasma sensor of UV and IR. The robot based laser welding system is developed for the precision seam tracking and the real-time monitoring of welding quality.

scholarly journals Study on Seam Tracking System for Laser Welding using 6-axis Articulated Robot

2018 ◽  
Vol 36 (1) ◽  
pp. 111-121
Author(s):  
Toshimitsu MAEDA ◽  
Isao TORIGOE ◽  
Shouki KASUGA ◽  
Muneharu KUTSUNA
Keyword(s):  
Laser Welding ◽  
Tracking System ◽  
Seam Tracking ◽  
Articulated Robot

A study on an automatic seam tracking system by using an electromagnetic sensor for sheet metal arc welding of butt joints

2002 ◽  
Vol 216 (6) ◽  
pp. 911-920 ◽  
Author(s):  
B-H You ◽  
J-W Kim
Keyword(s):  
Sheet Metal ◽  
Arc Welding ◽  
Tracking System ◽  
Weld Line ◽  
Welding Process ◽  
Seam Tracking ◽  
Displacement Sensor ◽  
Tracking Accuracy ◽  
Metal Arc Welding ◽  
Electromagnetic Sensor

Many sensors, such as the vision sensor and the laser displacement sensor, have been developed to automate the arc welding process. However, these sensors have some problems due to the effects of arc light, fumes and spatter. An electromagnetic sensor, which utilizes the generation of an eddy current, was developed for detecting the weld line of a butt joint in which the root gap size was zero. An automatic seam tracking system designed for sheet metal arc welding was constructed with a sensor. Through experiments, it was revealed that the system had an excellent seam tracking accuracy of the order of ±0.2mm.

Intelligent seam tracking using ultrasonic sensors for robotic welding

Robotica ◽  
1997 ◽  
Vol 15 (3) ◽  
pp. 275-281 ◽  
Author(s):  
Ajay Mahajan ◽  
Fernando Figueroa
Keyword(s):  
Tracking System ◽  
Welding Process ◽  
Seam Tracking ◽  
Robotic Welding ◽  
Ultrasonic Sensors ◽  
Intelligent Sensor ◽  
Novel Approach ◽  
Transmitted Waves ◽  
Welding Torch ◽  
Arc Welding Process

This paper presents a novel approach for seam tracking using ultrasonics. An ultrasonic seam tracking system has been developed for robotic welding which tracks a seam that curves freely on a two-dimensional surface. The seam is detected by scanning the area ahead of the torch and monitoring the amplitude of the waves received after reflection from the workpiece surface. Scanning is accomplished by using two ultrasonic sensors (a transmitter and a receiver) mounted on a stepper motor such that the transmitter angle is the same as the receiver angle. The motor is mounted on the end-effector just ahead of the welding torch and covers a ninety degree arc in front of the torch. If there is no seam then the receiver receives most of the transmitted waves after reflection, but if there is a seam then most of the transmitted waves are dispersed in directions other than that of the receiver. The system has been tested and is very robust in the harsh environments generated by the arc welding process. The robustness of the system stems from using various schemes such as time windowing, a waveguide, air and metal shields, and an intelligent sensor manager. This ultrasonic system offers some distinct advantages over traditional systems using vision and other sensing techniques. It can be used to weld very shiny surfaces, and is a very economical method in terms of cost as well as computational intensity. The system can be used to detect seams less than 0.5 mm wide and 0.5 mm deep.

Automated seam tracking system based on passive monocular vision for automated linear robotic welding process

2017 ◽  
Author(s):  
Átila Astor Weis ◽  
Adriano Velasque Werhli ◽  
Nelson L. Duarte Filho ◽  
Luciane Baldassari Soares ◽  
Cristiano Rafael Steffens ◽  
...  
Keyword(s):  
Tracking System ◽  
Welding Process ◽  
Monocular Vision ◽  
Seam Tracking ◽  
Robotic Welding

Laser vision seam tracking system based on proximal policy optimization

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yanbiao Zou ◽  
Hengchang Zhou
Keyword(s):  
Weld Seam ◽  
Tracking System ◽  
Tracking Error ◽  
Welding Process ◽  
Seam Tracking ◽  
Reference Image ◽  
Image Block ◽  
Content Type ◽  
Weld Seam Tracking ◽  
Policy Optimization

Purpose This paper aims to propose a weld seam tracking method based on proximal policy optimization (PPO). Design/methodology/approach By constructing a neural network based on PPO and using the reference image block and the image block to be detected as the dual-channel input of the network, the method predicts the translation relation between the two images and corrects the location of feature points in the weld image. The localization accuracy estimation network (LAE-Net) is built to update the reference image block during the welding process, which is helpful to reduce the tracking error. Findings Off-line simulation results show that the proposed algorithm has strong robustness and performs well on the test set of curved seam images with strong noise. In the welding experiment, the movement of welding torch is stable, the molten material is uniform and smooth and the welding error is small, which can meet the requirements of industrial production. Originality/value The idea of image registration is applied to weld seam tracking, and the weld seam tracking network is built on the basis of PPO. In order to further improve the tracking accuracy, the LAE-Net is constructed and the reference images can be updated.

Application of Microcomputers to Automatic Weld Quality Control

1980 ◽  
Vol 102 (2) ◽  
pp. 62-68 ◽  
Author(s):  
M. Tomizuka ◽  
D. Dornfeld ◽  
M. Purcell
Keyword(s):  
Control Method ◽  
Computer Control ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Seam Tracking ◽  
Process Time ◽  
Welding Parameters ◽  
Weld Quality ◽  
On Line ◽  
Welding Processes

The demand for increased productivity of welding operations has led to the expanded use of computer control to allow higher production rates while maintaining weld quality. The charateristics of the gas metal arc welding process and the relationship between welding parameters, the desired output of the welding process, and the automation of the process are discussed. A strategy for two-axis welding torch positioning and velocity control is developed based on preview control techniques. To evaluate the applicability of the proposed control method the motion of heat source along different welding paths is simulated on an analog computer with on-line control of process time constants by an LSI-11 microcomputer. The simulation results show that high quality seam tracking can be accomplished by controlling the torch motion using the proposed method. The method appears to be suitable for on-line control of welding processes.

Ripple Line Fillet Seam Tracking with Visual Sensors in Welding Process

2013 ◽  
Vol 579-580 ◽  
pp. 46-51 ◽  
Author(s):  
Qi Lin Bi ◽  
Yan Ming Quan
Keyword(s):  
Tracking System ◽  
Welding Process ◽  
Base Plate ◽  
Seam Tracking ◽  
Welding Parameter ◽  
Motion Controller ◽  
Side Plate ◽  
Image Information ◽  
Time Motion ◽  
Welding Torch

To overcome the problems resulting from weldment trimming and assemble errors, thermal deformation, arc blow, etc., a set of new tracking system of fillet seam for automatic corrugated plate welding was put forward based on machine vision technology. The tracking system included two cameras: the precursor was set in front of the welding torch (a corrugation cycle far away), for capturing the linear laser projected on the side plate and the base plate; the another one was installed over the melting pool for capturing the image of welding torch tip and the seam. The processed image information from the precursor camera was used to track the fillet seam three-dimensional trajectory and the seam width, according to the information the welding motion controller and the welding power made preplanning; the processed torch tip and seam image information was sent to the motion controller and the welding power so that they could make real-time motion and welding parameter adjustment. Computer simulation proved that this new tracking system could work efficiently.

Underwater Wet Weld Seam Tracking Based on Passive Visual Sensor

2013 ◽  
Vol 683 ◽  
pp. 725-728
Author(s):  
Bo Chen ◽  
Chuan Bao Jia ◽  
Ji Cai Feng
Keyword(s):  
Weld Seam ◽  
Tracking System ◽  
Water Environment ◽  
Welding Process ◽  
Seam Tracking ◽  
Visual Sensor ◽  
Weld Seam Tracking ◽  
Influence Of Water ◽  
Image Processing Algorithms ◽  
Weld Automation

Weld seam tracking system is urgently needed in weld automation process, but it has not been well studied in underwater weld applications. This paper used visual sensor to automatically monitor the weld seam in underwater wet weld process, and image processing algorithms were developed to remove the influence of water environment on the captured image and automatically obtain the weld torch deviation, and the weld torch was adjusted automatically according to the deviation obtained by the image, experiment results showed that the system could meet the requirements of underwater wet welding process.

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