The Research Of Weld Tracking Technology Based On Swinging Arc Sensor

Welding is an important processing method in the modern industry. Asthe continuous development of modern industry, the standard for weldingquality and efficiency is stricter and stricter. Weld automatic tracking is anessential part of the automatic welding processing, which plays an essentialrole in improving the welding quality and efficiency.The weld tracking system based on swing arc sensor which can beachieved by using welding current signal. The system scans welding groovesby using the swinging arc sensor, so the change of the welding current is inaccordance with the regular change of the arc length. Then the informationabout weld deviation can be achieved by analyzing the change of thewelding current. With a simple structure and good spatial accessibility, theswinging arc sensor is the hot topic of weld tracking in welding area.Based on the working state of swinging arc sensor under the situationof spray transfer and short circuiting transfer, the mathematical model hasbeen built. Then by using the Simulink tool bar of MATLAB the simulationmodel of the system has been built. Meanwhile, aiming at the influences ofthe swing frequency, swing width, and the horizontal deviation on weldingcurrent waveform, we make the simulation. The research of mathematicalmodel and simulation model provide the theoretical direction for the gainingof deviation information from current waveform afterward.During the process of welding process, considering welding currentsignal can be influenced by the short circuit transfer, the splash, the dust, theelectrical arc, makes the signal full of noises, so in accordance with thesystem requirement for welding current we choose the Bessel filter. Afterthe filtration process the current signal is much clearer than ever, it makesgood preparation for the gaining of deviation information afterward.According to simulation of the welding arc sensor under the situation ofshort circuit transfer combined with the welding current waveform, we comeup a method called 'left and right limits of regional integration method' which can achieve the deviation information has been came up. This methodcan restrict the random noises at a certain degree, and because the datarequired to be processed is less, this method can also accelerate the circulaterate of program, as well as increases the tracking accuracy of welding.Finally a set of weld tracking hardware platform based on the swingingarc sensor has been built, and by using it the weld tracking experiment hasbeen made, getting a quite satisfactory tracking effect. The experimentresults show that the real-time weld tracking system introduced in this paperis practical.