Dynamic Estimation of Full Penetration Using Geometry of Adjacent Weld Pools

Abstract

Control of weld penetration is currently one of the most important and crucial research issues in the area of welding. The weld pool can provide accurate and instantaneous information about the weld penetration, however, the establishment and confirmation of the correlation between weld pool and weld penetration require numerous accurate measurements and suitable geometrical modeling of weld pool. A normalized model is proposed to characterize the weld pool two-dimensionally. More than 6,000 weld pools are measured from experiments using a developed real-time weld pool sensing system. A data analysis shows that the weld penetration is correlated with the weld pool which is specified by the three characteristic parameters proposed in the study. However, the correlation is nonlinear. To approximate the complicated nonlinearity, neural networks are used. Comparative modeling trails show that the weld penetration can be more accurately calculated if the adjacent weld pools are also used. This implies that the correlation between the weld penetration and weld pool is dynamic. Hence, an on-line nonlinear dynamic estimation system is developed to estimate the weld penetration.

Three-dimensional vision applications in GTAW process modeling and control

“…A polar coordinate model was presented to describe the pool boundary, and the model parameters could be identified in real time to determine the weld penetration [20]. A parameter model was obtained, and it presented a symmetric and normalized description of the weld pool [21]. The 2D parametric model of weld pool is presented as…”

“…Based on the model, the desired fusion state could be achieved by using a predictive controller [21].…”

“…[21], the weld pool was characterized by three parameters: the length ratio b, the relative width w r , and the length of the pool L, and related models were obtained. In Ref.…”

Neurofuzzy model-based weld fusion state estimation

“…In a previous study [13], the following parametric model was proposed to model the boundary of the weld pool: (Fig. 2).…”

Real-Time Measurement of Three Dimensional Weld Pool Surface in GTAW

“…The model used to fit the boundary of the weld pool is from literature [59] and demonstrated in Fig. 16:…”