A Multi-objective Approach to Solve the Build Orientation Problem in Additive Manufacturing

Abstract

Additive manufacturing (AM) has been increasingly used in the creation of three-dimensional objects, layer-by-layer, from threedimensional (3D) computer-aided design (CAD) models. The problem of determining the 3D model printing orientation can lead to reduced amount of supporting material, build time, costs associated with the deposited material, labor costs, and other factors. This problem has been formulated and studied as a single-objective optimization problem. More recently, due to the existence and relevance of considering multiple criteria, multi-objective approaches have been developed. In this paper, a multi-objective optimization approach is proposed to solve the part build orientation problem taking into account the support area characteristics and the build time. Therefore, the weighted Tchebycheff scalarization method embedded in the Electromagnetism-like Algorithm will be used to solve the part build orientation bi-objective problem of four 3D CAD models. The preliminary results seem promising when analyzing the Pareto fronts obtained for the 3D CAD models considered. Concluding, the multi-objective approach effectively solved the build orientation problem in AM, finding several compromise solutions.

Bayesian optimisation of part orientation in additive manufacturing

“…However, it must be noted that using convex hulls may not be appropriate for certain part geometries, particularly those containing concave features. Matos et al (2019) used weighted Tchebycheff scalarization method to address the multi-objective optimisation challenge of amount of supporting material and build time. However, they did not report any figures regarding the number of model evaluations.…”

Implementation of Robust Multi-objective Optimization in the Build Orientation Problem

“…The other measure of the quality used in this study is called the support area, that corresponds to the total contact area of the external supports with the object [5,8,13]. Mathematically, the support area, SA, is given by…”

“…Matos et al in [5] used a global optimization method, the Electromagnetism-like algorithm, to optimize six printing quality measures in order to find the optimal build orientations of six 3D CAD models. Moreover, different multi-objective approaches have been developed in order to determine a set of trade-off optimal build orientations, when optimizing more than one quality measure simultaneously [10,11,12,13,14,15]. For example, in [16] the authors applied the NSGA-II multi-objective method to determine the Pareto optimal set of build orientations based on four quality measures (the support area, the build time, the surface roughness, and the overall quality of the surface).…”

Many-objective optimization of build part orientation in additive manufacturing

“…Ga et al (2019) proposed a multi-objective strategy using a weighted sum method in order to reduce the support volume, build time and costs and increase the surface quality, depending on the orientation chosen by the user and the weights associated with each objective function. Matos, Rocha, Costa, and Pereira (2019) proposed a multi-objective problem using the Tchebycheff method with the Electromagnetism-like algorithm to minimize the area of the object in contact with the supporting structures and the build time of four 3D models. The study involved the combination between two objectives.…”