Abstract

This work investigates surrogate modeling techniques for learning to approximate a computationally expensive function evaluation of 3D models. Radial Basis Functions (RBF), Kriging, and shallow 1D analogs of popular deep 2D image classification neural networks are investigated in this work. We find the nonintuitive result that departing from neural networks to decode latent representations of 3D objects into performance predictions is far more efficient than using a neural network decoder. We find that an RBF surrogate model is able to approximate the lift and drag coefficients of 234 aircraft models with a mean absolute error of 1:97e–03, and trains in only 3 seconds. Furthermore, the RBF surrogate model is able to rank a set of designs with an average percentile error of less than 8%. In comparison, a 1D ResNet achieves an average absolute error of 1:35e–03 in 38 minutes for the same test case. We validate the comparable accuracy of the four techniques through a test case involving 214 3D watercraft models, but we also find that the distribution of the performance values of the data, in particular the presence of many outliers, has a significant negative impact on accuracy. These results contradict a common perception of neural networks as an efficient “one-size-fits-all” solution for learning black box functions, and suggests that even within systems that utilize multiple neural networks, potentially more efficient alternatives should be considered for each network in the system.

This content is only available via PDF.

Article PDF first page preview

Article PDF first page preview
You do not currently have access to this content.