Abstract: There is no doubt that imitating and modeling of the skilled human welder's responses as well as programming it is one of optical method for rapid developing intelligent robotic welding technology. However, it is the key step of simultaneously sensing and measuring the weld torch orientation and weld pool characteristics to realize the program of human welder's responses. Aiming at the independence of measurement system of weld torch orientation and weld pool characteristics and the synchronously coupled analyzing requirements of interaction between human welder and weld pool, a mathematical transfer model of sensor-cardon-tungsten tip and a model of the traveling weld pool coupled with the welding torch orientation was built up, respectively, and its effectiveness and accuracy was verified by robot swing experiments with given parameters. The results show that the error of weld torch orientation α and β is both less than 1.2°, and the error of γ angle is about 1.5°. The data of weld torch orientation with the received error can be obtained using the coupled model. Furthermore, the experiments that the welding torch orientation operated by different level skilled welder affects on the weld pool status were performed and analyzed. Comparison of the experimental results indicates that the untrained welder without any welding experience irregularly and randomly adjusts the welding torch and lacks the basic welding skills and the awareness interactived with the weld pool as well as cannot ensure the weld process stability and high quality. Long trained human welder can normatively operate the welding torch orientation and soundly control the weld pool morphology via his/her observations and pass-trained experience, reflecting a strange interactive awareness and guaranteeing the dynamic balance of weld pool and full penetration.

Key words: human welder's responses, weld metal fluid flow behavior, weld torch orientation, 3D sensing, coupled model