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The purpose of this paper is to find a theoretical reference to adjust the unsymmetrical arc shape and plasma flow of overlapping deposition in wire arc additive manufacturing (WAAM) and ensure the effect of the gas shielding and stable heat and mass transfer in deposition process. The multiphysical numerical simulation and physical experiment are used for validation.

In this study, welding torch tilt deposition and external parallel magnetic field–assisted deposition are presented to adjust the unsymmetrical arc shape and plasma flow of overlapping deposition, and a three-dimensional numerical model is developed to simulate the arc of torch tilt overlapping deposition and external parallel magnetic field–assisted overlapping deposition.

The comparison of simulated results indicate that the angle of welding torch tilt equal to 20° and the magnetic flux density of external transverse magnetic field equal to 0.001 Tesla are capable of balancing the electric arc and shielding gas effectively, respectively. The arc profiles captured by a high-speed camera match well with simulated results.

These studies of this paper can provide a theoretical basis and reference for the calibration and optimization of WAAM process parameters.

The purpose of this paper is to study the wire and arc additive manufacturing (WAAM) method and path planning algorithm of truss structure parts, to realize the collision-free rapid prototyping of truss structures with complex characteristics.

First, a point-by-point stacking strategy is proposed based on the spot-welding mode of cold metal transfer welding technology. A force analysis model of the droplet is established, which can be used to adjust the posture of the welding torch and solve the collapse problem in the WAAM process of the truss structure. The collision detection model is developed to calculate the interference size between the truss structure and the welding torch, which is used to control the offset of the welding torch. Finally, the ant colony algorithm has been used to optimize the moving path of welding torch between truss with considering the algorithm efficiency and collision avoiding and the efficiency of the algorithm is improved by discretizing the three-dimensional workspace.

A series of experiments were conducted to prove the validity of the proposed methods. The results show that the wire feeding speed, welding speed are the important parameters for controlling the WAAM process of truss parts. The inclination angle of the welding torch has an important influence on the forming quality of the truss.

The force analysis model of truss structure in the WAAM process is established to ensure the forming quality and a collision-free path planning algorithm is proposed to improve forming efficiency.

The purpose of this study is to establish a method for accurately extracting torch and seam features. This will improve the quality of narrow gap welding. An adaptive deflection correction system based on passive light vision sensors was designed using the Halcon software from MVtec Germany as a platform.

This paper proposes an adaptive correction system for welding guns and seams divided into image calibration and feature extraction. In the image calibration method, the field of view distortion because of the position of the camera is resolved using image calibration techniques. In the feature extraction method, clear features of the weld gun and weld seam are accurately extracted after processing using algorithms such as impact filtering, subpixel (XLD), Gaussian Laplacian and sense region for the weld gun and weld seam. The gun and weld seam centers are accurately fitted using least squares. After calculating the deviation values, the error values are monitored, and error correction is achieved by programmable logic controller (PLC) control. Finally, experimental verification and analysis of the tracking errors are carried out.

The results show that the system achieves great results in dealing with camera aberrations. Weld gun features can be effectively and accurately identified. The difference between a scratch and a weld is effectively distinguished. The system accurately detects the center features of the torch and weld and controls the correction error to within 0.3mm.

An adaptive correction system based on a passive light vision sensor is designed which corrects the field-of-view distortion caused by the camera’s position deviation. Differences in features between scratches and welds are distinguished, and image features are effectively extracted. The final system weld error is controlled to 0.3 mm.

Aims to present missing knowledge of welding and sensor application with rotating torch to the technically and economically meaningful employment. With the help of this knowledge, on the one hand, the potential user is to be informed about the applicability of the system in the context of his production line and his products and on the other hand, the classification of the system in the range of the alternatives available on market.

Introduces the welding operation and experimental results of rotating torch integrated with a sensor device using a 6‐axis robot. Performed various laboratory experiments investigating variable frequency values with different torch orientations.

Figures out the optimum frequency and torch orientation to obtain ultimate welding geometry by means of compensating gaps with increased weld root. Observed the possibility of out‐of‐position welding.

In this manner, provides a great scope as a pioneer application in industry and a guidance for forthcoming researches.

Allows welding of thin sheet metals.

Presents a seminal concept in the field of any industrial applications such as marine and pipeline construction.

The aim of this study was to develop a new generation of automatic systems based on cutting-edge design and practical welding physics to minimize downtime caused by defects and machine faults on the barges. Automatic welding has been used frequently on offshore pipeline projects.

An automated welding robot system for sub-sea pipeline installation was constructed. The system utilized the double-car double-torch welding, which is light-weight and compact, suited for offshore applications. Several state-of-the-art technologies were integrated into the control system design, including a heterogeneous network based on EtherCAT technology, network communications based on CANopen, motor synchronization, all-position welding, etc. In addition, the utilization of the CAN bus reduced the number of cable lines and increased the extensibility of the proposed welding robot system. An internal clamp with copper shoes assured a nice root weld and narrow bevel design and the welding efficiency was improved accordingly.

The trial was carried out to verify the rationality and effectiveness of the proposed automated system. The deposition rate of the backing welding could reach 17.78 kg/h; the average time for each welding was 340 s. This system was unique in that it features a dual-torch welding head that allowed for the deposition of one run with twice as much material as a single torch head. The experiment showed that the double-vehicle double-torch mode can greatly improve the welding efficiency of pipeline installation during the welding process.

The automated welding robot system will be applied to offshore pipeline projects.

This robot is the first submarine pipeline installation welding robot to use a heterogeneous network based on EtherCAT technology. Various aspects of the submarine pipeline installation welding robot’s design and performance were discussed, including mechanical body design, control system design and welding process specification.

Welding is becoming increasingly unacceptable as a manual job and this is causing an acceleration in the trend towards automation. This paper briefly reviews some recent efforts at automating welding processes, including a program in the UK by the National Engineering Laboratory and the Welding Institute, and considers the future progress and effects of automation in this field.

SINCE their introduction into this country a few years ago, the inert‐gas‐shielded welding processes have rapidly become preeminent in the light‐alloy field, where their advantages are well known. At the Luton Establishment of Messrs D. Napier and Son, Ltd., these processes have been the subject of intensive development during the last three years, and this work has made possible their current adoption in various forms as normal productive processes. Wherever possible, mechanization has been introduced for reasons discussed later, and components are being produced in a variety of light alloys. The majority of the applications are highly stressed fabrications whose physical soundness and dimensional accuracy require to be of a particularly high standard.

The purpose of this paper is to describe the development of a low cost fully automatic computer controlled oxy‐fuel cutting system for tubular members. Operation of the system should be easy even for unskilled technicians.

The robot consists of one revolute axis and two linear axes. As the pipe rotates, two cutting torches move linearly at both ends of the pipe to complete the cutting process in one rotation. Both torch's cutting paths are calculated in a computer offline. Tool paths are then loaded in a micro control unit for each cutting. When the pipe is attached to the system, the whole cutting process can be completed automatically. The mathematical method for calculation of the geometry of intersecting cylinders is also explained in this paper.

The automation of oxy‐fuel cutting process brings enhancement in the final product quality, considerable increase of repeatability, reduction of rework and reduction of the cutting time.

The use of this automated flame cutting system proved to be extremely viable. Although, there are commercial devices for cutting tubular members, the product shown here is completely different than the previous systems. This device can be called a CNC system due to its capability of being completely programmable and automatically carrying through all cutting activities. This is the first system cutting both sides of pipe simultaneously to reduce cutting time.

Robot welding of large multiple pass welds is being achieved at Vickers Defence Systems following a collaborative project.

The purpose of this paper is to develop a build strategy for inclined thin-walled parts by exploiting the inherent overhanging capability of the cold metal transfer (CMT) process, which release wire-arc additive manufacturing from tedious programming work and restriction of producible size of parts.

Inclined thin-walled parts were fabricated with vertically placed welding torch free from any auxiliary equipment. The inclined features were defined and analyzed based on the geometrical model of inclined parts. A statistical prediction model was developed to describe the dependence of inclined geometrical features on process variables. Based on these models, a build strategy was proposed to plan tool path and output process parameters. After that, the flow work was illustrated by fabricating a vase part.

The formation mechanism and regulation of inclined geometrical features were revealed by conducting experimental trials. The inclined angle can be significantly increased along with the travel speed and offset distance, whereas the wall width is mainly dependent on the ratio of wire feed speed to travel speed. In contrast to other welding process, CMT has a stronger overhanging capability, which provides the possibility to fabricate parts with large overhanging features directly with high forming accuracy.

This paper describes a novel build strategy for inclined thin-walled parts free from any auxiliary equipment. With the proposed strategy, a complex structural component can be deposited directly in the rectangular coordinates additive manufacturing system, indicating infinite possibilities on the producible size of the parts. Moreover, equipment requirements and tedious program work can also be significantly reduced.