Page 61 - MSAM-4-3
P. 61

Materials Science in Additive Manufacturing                         Bead geometry prediction in laser-arc AM









































            Figure 1. Schematic illustration of the laser-arc hybrid additive manufacturing system

             A                                                 yield their own prediction outputs. Thereafter, particle
                                                               swarm optimization (PSO) iteratively updates the weights
                                                               of the models, driving the weighted prediction error
                                                               downward until convergence and ultimately producing an
             B                                                 ensemble prediction that fuses the four models. Finally, in
                                                               accordance with Equation II, the mean absolute percentage
                                                               error is calculated for each base model as well as for the
                                                               ensemble.

                                                                               y
                                                                       1  n  y    i
                                                                            i
                                                               MAPE            100%                     (II)
             C                                                         n  i1  y i
                                                                 Particle swarm optimization is a global optimization
                                                               technique inspired  by swarm  intelligence, which  locates
                                                               optima by modeling the coordinated, iterative movement of
                                                               many particles within a multidimensional search domain.
                                                               Every particle acts as a potential solution; its velocity and
            Figure  2. Schematic diagram shows the quantification of weld-bead   position are continually updated with reference to its
            width and height. (A) Actual morphology of a weld bead in the   personal best and the swarm’s global best, which hastens
            training set. (B) 3D point cloud obtained through line-laser scanning.   convergence and elevates search efficiency.
            (C) Extracted weld-bead contour
                                                                 To simplify the weight optimization for multi-model
            subjected to hyperparameter optimization and training   ensembles, we introduce, under the PSO paradigm, a one-
            on the training and validation datasets. The tuned models   dimensional discrete index encoding (ODIE) that assigns
            are subsequently deployed on the test set, where they each   weights to the base regression models with high efficiency.


            Volume 4 Issue 3 (2025)                         4                         doi: 10.36922/MSAM025220036
   56   57   58   59   60   61   62   63   64   65   66