Research on laser-arc hybrid welding technology for long-distance pipeline construction

In recent years, the research on pipeline laser-arc hybrid welding technology has been the important and difficult in the field of welding all over the world. China Petroleum Pipeline Research Institute Co. Ltd. has firstly developed pipeline laser-arc hybrid welding system in China, and executed the welding tests based on X70/X80 steel. Preliminary experiment results showed that hybrid welding could meet the requirements of related standards such as API1104,ASME,etc., the mechanical properties of girth seam are qualified in the case that there were no internal defects. With the development of high-power fiber laser and the continuous improvement of welding equipment, laser-arc hybrid welding technology for pipeline field welding will be available soon.

A method of initial welding position guiding for arc welding robot based on visual servo control

In order to solve the visual guiding task of initial welding position for arc welding robot, this paper presents a practice prone image based visual servo control strategy without calibration, and we perform validating experiments on a nine DOF arc welding robot system. Experimental results illustrate presented method has the function to fulfill the task of welding robot initial positioning with certain anti jamming ability. This method provides a basis for guiding welding gun to initial welding pose with real typical seam’s image properties to replace flag block properties, and is a significant exploit to realize visual guiding of initial welding position and seam tracing in robot welding system.

Study on full automatic arc welding machine for spherical tank

A full automatic welding machine for spherical tanks' all position multi layer welds has been developed. This machine is mainly composed of a two dimension seam tracking system based on microcomputer's memory and a welding tractor as well as rail. The main features of the machine are: while welding the first layer of a seam, its microcomputer system can analyze and store the tracing information from a two dimension sensor, and control the welding head device to realize two dimension real time tracing; while welding the second layer up to the top layer of the seam, it can realize two dimension tracing based on the memorial data, automatically determine the layer number and continually sway the welding head. The welding test shows that the machine has good tracing and welding behavior, and is suitable for spherical tank's all position multi layer welds.

An artificial neural network for detecting weld position in arc welding process

A kind of self organizing artificial neural network used for weld detection is presented in this paper, and its concepts and issues are discussed. The network can transform the weld visual information into typical patterns and match with the weld data collected on line, and so realize the accurate detection of the weld position in arc welding process.

Application of Image Morphology in Detecting and Extracting the Initial Welding Position

A method of image morphology in detecting and extracting the initial welding position during the autonomous welding process is described.During the process,firstly visual sensing technology is used to capture the straight seam image,and secondly the image edges are detected by morphological corrosion edge detection algorithm,with which can retain the critical information while filter other interferences effectively at the same time.Then morphological processing algorithm is used to conduct the direction of filter by selecting the multidirectional linear structuring elements and finally get the initial weld position point coordinates with the Hough transform.The algorithm is simple,rapid,self-adaptability with high accuracy for interferences except long lines so as to accomplish the entire process of detecting the initial welding position.It can meet the practical demands of automatic guidance for robotic welding.