A study of a dual-electromagnetic sensor system for weld seam tracking of I-butt joints

Author(s):  
J-W Kim ◽  
J-H Shin

Seam tracking systems for the arc welding process use various kinds of sensor including the arc sensor, vision sensor and laser displacement sensor. Among the various sensors available, the electromagnetic sensor is one of the most useful methods, especially in sheet metal butt-joint arc welding, primarily because it is hardly affected by the intense arc light and fumes generated during the welding process, or by the surface conditions of the weldment such as paint marks and scratches. In this study, a dual-electromagnetic sensor, which utilizes the induced current variation in the sensing coil due to the eddy current variation in the metal near the sensor, was developed for the arc welding of sheet metal I-butt joints. The dual-electromagnetic sensor thus detects the offset displacement of the weld line from the centre of the sensor head, even when there is no gap in the joint. A set of design variables for the sensor was examined to determine the maximum sensing capability through repeated experiments. Seam tracking was performed by correcting the position of the sensor to the amount of offset displacement determined during each sampling period. From the experimental results, the developed sensor system showed an excellent capability for weld seam detection and tracking when the sensor-to-workpiece distance was less than 5mm.

Author(s):  
B-H You ◽  
J-W Kim

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.


Author(s):  
Ye Wang ◽  
Mi Zhao ◽  
Hongyu Xu ◽  
Maoliang Hu ◽  
Zesheng Ji

Metal inert gas arc welding process was implemented to join 6063T6 wrought alloy and ADC12 die-casting alloy using ER4047 filler metal. The microstructure of the weld seam and weld interface was investigated. The bonding strength of the butt joints was tested by Charpy U-notch impact test and tensile test. The results showed that a sound welding butt joint with finely silicon particles and excellent mechanical properties was formed, and the size of the silicon particles was nearly 2 μm. Compared with 6063T6 wrought alloy, the impact absorbing energies and the tensile strengths of the butt joint were higher and reached 1.173 kJ/cm2 and 205 MPa, respectively, and the fractures of all tensile specimens occur at the 6063T6 aluminum.


2021 ◽  
Author(s):  
Yanfeng Gao ◽  
Jianhua Xiao ◽  
Genliang Xiong ◽  
Hua Zhang

Abstract It is essential to sense the deviation of weld seam real-timely in robotic welding process. However, welding process always accompanied with high temperature, strong arc light and background noises, which significantly affects the application of sensors. In this study, a novel acoustic sensor was developed. This sensor consists of two microphones. Based on the sound signals collected by these two microphones, the deviation of weld seam was detected. The frequency response of the developed acoustic sensor was studied through simulation method firstly, and then the sensing performance of it was analyzed with experiments. The experimental results show that the developed acoustic sensor has a linear property for the deviation detection of V-groove weld seam. This research provides a novel method for weld seam tracking.


2018 ◽  
Vol 15 (6) ◽  
pp. 172988141881620
Author(s):  
Reza Ebrahimpour ◽  
Rasul Fesharakifard ◽  
Seyed Mehdi Rezaei

Welding is one of the most common method of connecting parts. Welding methods and processes are very diverse. Welding can be of fusion or solid state types. Arc welding, which is classified as fusion method, is the most widespread method of welding, and it involves many processes. In gas metal arc welding or metal inert gas–metal active gas, the protection of the molten weld pool is carried out by a shielding gas and the filler metal is in the form of wire which is automatically fed to the molten weld pool. As a semi-metallic arc process, the gas metal arc welding is a very good process for robotic welding. In this article, to conduct the metal active gas welding torch, an auxiliary ball screw servomechanism is proposed to move under a welder robot to track the welded seam. This servomechanism acts as a moving fixture and operates separately from the robot. At last, a decentralized control method based on adaptive sliding mode is designed and implemented on the fixture to provide the desired motion. Experimental results demonstrate an appropriate accuracy of seam tracking and error compensation by the proposed method.


2021 ◽  
Author(s):  
Yinshui He ◽  
Zhuohua Yu ◽  
Ziyi Xiao ◽  
Jian Le

Abstract In this paper, a robust stable three-dimensional (3D) seam tracking method is investigate based on the Kalman filter (KF) and machine learning during the multipass gas metal arc welding process with a T-joint of 60 mm thickness. The laser vision sensor is used to profile the weld seam, and with the reference image captured before arcing a scheme is proposed to extract the variable weld seam profiles (WSPs) using scale-invariant feature transform and the clustering algorithm. An effective slope mutation detection method is presented to identify the feature points of the extracted WSP, namely the candidate welding positions. In order to lower the impact of fake welding positions on seam tracking, a Bayesian Network model is first built to implement fault detection and diagnosis for the visual feature measurement process using the involved process parameters and the trigger rule. A KF, as an estimator, is then established to further stabilize the tracking process combing with a self determination algorithm of the measurement result. With the visual calibration technology, 3D seam tracking is realized. Seam tracking results show that the proposed method overcomes the tremor of the tracking position and multiple fake candidate welding positions on tracking accuracy, and the tracking accuracy is 0.6 mm. This method provides potential industrial application value for industrial manufacturing with large-scale components.


2021 ◽  
Author(s):  
Hao Dong ◽  
Cai Yan ◽  
Zihan Li ◽  
Xueming Hua

Abstract Weld seam quality prediction is important for intelligent robot welding. Current models with single scale feature extraction methods meet difficulty when facing complex physical instability in welding process. In this paper, a novel feature extraction method based on sliding multiscale windows is proposed to improve model accuracy and calculation speed. A group of windows with different width are established to extract multiscale information of complex objective. Windows slide throughout process and be synchronized on the timeline for feature correlation. Based on the feature vector extracted from multiscale-windows, Support vector machine (SVM) with radial basis function (RBF) kernel is used after signal denoising and dimension reduction by Primary components analysis (PCA). The best window width is determined by model training. The proposed method is used to predict seam quality for Plasma arc welding (PAW) in the field of shipbuilding. The results show that the model with multiscale feature extraction is helpful to improve prediction precision and recall ratio.


Author(s):  
O. I. Filippov ◽  
M. A. Sholokhov ◽  
V. A. Erofeev ◽  
S. I. Poloskov

The possibilities of computer engineering analysis of special features of double-sided multi-arc welding of vertical joints of tanks with thick shells for storing oil and oil products are shown. The analysis was carried out on the basis of a numerical implementation of the unconventional physical and mathematical model of the formation of a melt pool and a weld seam with two pairs of arcs on each side of the joint with a double-sided bevel. It was established that during weld formation with the movement of the electrode down (vertical down), the possibility of supplying the first pair of arcs with pulsed current should be taken into account, and for the second pairs, the possibility of lateral oscillation of the arcs in the groove with delays at the edges. During groove filling with the movement of the electrodes up (vertical up), their lateral oscillations and delays at the edges should be carried out according to an aperiodic law in order to minimize the effects of “magnetic blow”. For root formation, it is recommended to use pulsed welding, and during groove filling - high current welding with low welding speed. The results of the study can be used in the formation of scientifically-based requirements for the welding process and equipment for double-sided multi-arc welding of the vertical joints of tanks for storing oil and oil products.


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