| With the deep research on arc sensor, rotating arc sensor has an accelerated development andan wide application in V-type weld and fillet weld welding production because of that compactand simple structure; that without interference of arc light, arc heating, magnetic field and spatter;that welding point unified with detecting point so as to eliminate the problem of sensor in first;that completely real-time of arc sensor; that much better at dynamic quality and that more superioron controlling precision. Presently, there is not yet an accurately theoretical and mathematicalmodel of high speed rotating arc sensor, so building accurate theoretical mathematical modelcontributes to improving the deviation extracted accuracy of rotating arc sensor and improving therotating arc sensor tracks speed as that its further application is of great significance.In order to reduce the effect on rotating arc sensor signal of the robot, high accuracydouble-axis robot as rotating arc sensor motion control platform and a novel small vibration andcompact structure rotating arc sensor is designed, that construct the rotating arc sensor weldingsystem so as to weld continuity in narrow space, guarantee the stability of the welding process andmake preparations for the next research.Because of rotating arc sensor welding system theoretical mathematical model precisioneffected larger by arc form, and welding power external characteristic, and molten pool form, anddroplet transferring type and considering insufficient in existing model so as to make modelprecision lower, to improve rotating arc sensor welding system mathematical model, firstly forceon droplet and droplet transfer trace are analyzed firstly with the droplet transferring process ofrotating arc welding, and that effecting on system model is explained. Then analyzing the rotatingarc welding molten pool shape and explaining its effect on system model, so three-dimensionalreconstruction of molten pool is acted with image processing and surface fitting technology usingdouble-stripe visual sensor. And then welding current, electrode extension and arc length areobtained based on equivalent circuit model of the welding system, model of dynamic meltingmodel for electrode and model of welding point so as to establish a more accurate model of therotating arc sensor welding system, and to support the theoretical base for weld seam deviationextracted.To prove the rationality of its structure and ensure the reliability of sensor, using PRO/E and MSC.ADAMS software the novel rotating arc sensor simulation is acted, and the results verifythat the rotating arc sensor structure is valid and reliable. Based on the welding system with highaccuracy double-axis robot and rotating arc sensor, rotating arc sensor theoretical model and PIDcontrol strategy, the virtual prototype of weld seam tracking integrated control simulation modelis established with the character plane method to get weld seam deviation and adjusting PIDparameters to control the double-axis motion platform, the weld seam tracking system issimulated. This simulation strategy contribute a new idea for enhancing welding automation level,and meanwhile verify that rotating arc sensor mathematical model provides theoretical platformfor welding seam deviation recognition.Finally, the actual welding experiments are acted under deviation value given premise,gathering and filtering welding current signal, compared to rotating arc sensor in welding systemestablished in this article is verified the correctness of the model. Measurement accuracy using thecharacter plane method identifying weld seam deviation is analyzed, without consideration ofmolten pool shape the average error of its recognition is0.1002mm, with consideration of moltenpool shape is0.0378mm. Its accuracy is to meet actual requirements and three-dimensionalreconstruction of molten pool shape in this article is verified correct and realistic. Simulation andexperimental results both prove the effectiveness of the work of this research. |
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