Research The Relationship Between CO₂ Welding Parameters And Welding Pool Based On Robot Vision

With the development of science and technology welding automation and robotics has become an irreversible trend of modern welding. The welding quality and online quality detection of people demand is increasingly higher. CO₂ gas shielded arc welding is one of the method widely used in the production of welding.In the process of welding pool contains rich information about the welding quality.The weld pool shape information directly affect the weld formation and the inherent quality,while the welding parameters are the main factors affecting the weld pool geometry.So it is important for the development of welding technology programs and improvement of the welding quality with the welding process parameters and weld pool shape geometry.Given the less domestic research the theoretical research and engineering development have a certain gap with foreign countries.Therefore,the research on the use of visual techniques to obtain the pool shape parameter and study its relationship with the welding parameters.Firstly,in order to analysis the welding pool geometry that the experimental system based on visual and CCD image acquisition was established.In this paper,taking Q235 steel as the experimental material through a lot of welding robot experiments that lots of weld pool images was obtained at different welding current,welding speed and Welding posture.Secondly,As to the molten pool image characteristics of CO₂ arc welding, this chapter introduces a method for welding pool image processing which may access the pool edge information more accurately. Firstly, it is based on the fuzzy entropy filter to remove noise in the multilevel image, modify the image gray value, and enhance the edge of the welding pool image; secondly, it uses the canny operator edges positioning and adopts the mathematical morphology corrosion and expansion comprehensive processing edge of image; thirdly, the edge detection is used for grayscale morphological gradient; and finally, the molten pool characteristic parameters are calculated.Finally,this chapter combining the characteristics of CO₂ gas shielded arc welding used orthogonal experimental to analysis the relationship between welding parameters and the welding pool geometry.Through research and analysis of the inherent relationship between welding parameters and the shape of the pool.This article concluded that with the increase of welding current the weld width 、 penetration and area of the pool were presented to gradually increasing trend.But the weld width increases slightly than penetration.The tail of the molten pool angle were decreases and the molten pool shape gradually close to the ellipse.With the welding speed changes the weld width 、 penetration and weld pool volume change regularity and decreases as the speed increases.The tail shape gradually sharp with welding speed changes.Robotic welding angle will affect the angle between the gas nozzle and weldments, improper angle can cause spattering and arc unstable.Experiments on90°welding we can get High welding quality.When the welding voltage increases the weld width penetration increases and the impact on the weld width is more obvious.The impact on weld width that welding voltage> welding current> welding speed> welding angle and for the impact of penetration the current > voltage>Speed>angle.During the welding process the welding parameters:welding current is200 A, welding speed is 46 cm / min, welding angle is 90 and the welding voltage is18 V. During that parameters the welding process is stable.The interference factors are relatively small.The acquisition of image is clear and the weld quality is higher.This paper has some guiding significance for the optimization of CO₂ welding robot welding process.Laid the foundation for For the further study of weld pool and improve the welding quality.