Dynamic Modelling of Full Penetration Process in GTAW

The primary objective of this paper is to provide a mathematical model of the full penetration process for the purpose of designing a control scheme. According to analysis of the practical welding, six typical welding conditions are selected to perform the dynamic experiments. In order to insure the validity of identified models, the experiments are designed accordingly. Based on the input/output data, the moving-average models are built for both the individual and the general cases. However, the number of parameters is to large to be identified on-line due to the short duration of a single welding seam in our experiments. Therefore, in an effort to utilize an adaptive control strategy for this problem, we present a real time model containing fewer key parameters to be identified on-line. It is shown that this simpler model´s accuracy of the FPP is more than sufficient for our needs.