Control system for micro-beam plasma welding formation of thin-wall slit circular longitudinal seam

Abstract

The invention provides a control system for micro-beam plasma welding formation of a thin-wall slit circular longitudinal seam. The control system comprises a micro-beam plasma welding system, a precision welding workbench, a monocular coaxial telecentric visual sensing system and an MPAW (micro plasma arc welding) formation real-time control unit; the monocular coaxial telecentric visual sensing system is used to acquire a weld pool front transient image for thin-wall slit circular longitudinal seam micro-beam plasma welding, the MPAW formation real-time control unit is used to perform multi-electricity parameter synchronous acquisition of a welding process and online real-time prediction of seam formation feature parameters, and the micro-beam plasma welding system and the precision welding workbench perform real-time adjustment of welding process parameters according to a control command transmitted by the MPAW formation real-time control unit. The system enables an improvement in the quality reliability of welded products and success rate of single welding, is applicable to the micro-beam plasma welding process of thin-wall metal precision members in the fields such as aerospace manufacturing and is particularly applicable to precision welding of elastic elements such as ultrathin-wall membrane boxes and bellows.

Description

technical field [0001] The invention belongs to the technical field of welding quality control. The invention relates to a micro-beam plasma welding forming control system for thin-wall fine-gap ring longitudinal seams, which can be widely used in the micro-beam plasma welding process of thin-wall metal precision components in aerospace manufacturing and other fields. Background technique [0002] Thin-walled metal precision components are an indispensable and important component in high-end equipment manufacturing fields such as aerospace, military weapons, nuclear industry, medical equipment and biomedicine, and have strict requirements on weld quality and joint mechanical properties. Pulsed Micro-plasma Arc Welding (P-MPAW, Pulsed Micro-plasma Arc Welding) has the advantages of concentrated energy density, narrow heat-affected zone, high arc stability and precise control of heat input. An important welding and forming manufacturing method for thin-walled metal precision ...

AI Technical Summary

Problems solved by technology

Traditional visual inspection systems rely on standard industrial lenses with large magnification and high resolution to detect micro-objects. There are inherent optical imaging characteristics such as small depth of field and magnification changes with object distance, which is difficult to be directly applied to ultra-thin structures and fine welds. Welding dynamic molten pool detection, especially in actual welding production, weldment processing and assembly errors, molten pool self-oscillation phenomenon, weldment thermal deformation and external disturbance are difficult to avoid, all of which enable the micro-depth vision system to achieve clear imaging of the molten pool and Subsequent image processing and feature extraction bring difficulties; in addition, in many welding production occasions, due to the limitation of welding conditions, it is difficult to directly monitor the forming state of the back of the weld. Precise control of weld forming quality under the conditions of the model is a key problem that needs to be solved urgently in the welding and manufacturing of thin-walled metal precision components

[0005] After searching the existing technical documents and patents, it was found that the Chinese invention patent "Micro-beam plasma arc welding welding system cooperative control structure" with the patent application number of 200810200821.4 discloses a welding power control, welding seam tracking control, welding torch walking control, heat input control, arc stability control, and welding process control in one micro-beam plasma welding system, but the system does not involve welding pool visual sensing, and cannot monitor the dynamic welding pool behavior or obtain information from the molten pool surface. Morphological feature information of molten pool, and online precise control of weld penetration depth and weld width during micro-beam plasma welding cannot be realized; Chinese invention patent with patent application number 200510111327.7 "A dual-processor digital control for micro-beam plasma welding System and Control Method" discloses a dual-processor communication control system based on MCU single-chip microcomputer and DSP digital signal processing. By making full use of the respective advantages of MCU single-chip microcomputer and DSP digital signal processor, fast data transmission and optimization of welding external characteristics are realized. Control and other functions, but does not involve micro-beam plasma welding forming on-line control technology; the Chinese invention patent "Digital Human-Computer Interaction System for Micro-beam Plasma Welding" with the patent application number of 200610075063.9 discloses a menu-type human-computer interaction system for micro-beam plasma welding Computer interaction system, using single-chip microcomputer and DSP digital signal processor to realize human-computer interaction on the spot of micro-beam plasma welding, this system also does not involve micro-beam plasma welding forming on-line control technology

[0006] In summary, most of the existing micro-plasma arc welding (MPAW, Micro-plasmaArcWelding) systems at home and abroad only involve functions such as data communication between the welding machine and the host computer, human-computer interaction of the welding machine, online adjustment of welding process parameters, and automatic tracking of weld beads. At present, there is no research and report on the online control system of micro-beam plasma welding forming based on the fusion of multi-power feedback and molten pool visual information.

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