Austin Robotics and AI February Meetup

Presented with our partners Austin Robotics and AI

Speaker: Bhairavsingh Ghorpade, Senior Data Scientist at Space Cow LLC

Title: Enhancing BRepMFR for Machining Feature Recognition via Vision Transformers and Geometry-Aware Fourier Positional Encoding

Summary (Abstract): Accurate interpretation of geometry in 3D Boundary Representation (B-rep) CAD models is essential for AI-based machining feature recognition and process planning. The BRepMFR deep learning architecture demonstrated that transforming CAD models to face-adjacency graphs and applying a Graph Transformer is an effective approach to learning geometric and topological representations supporting machining feature recognition. However, this architecture relies on convolutional encoders and handcrafted descriptors that struggle to capture the global curvature and geometric variability inherent in industrial CAD models. To address these limitations, we introduce a Vision Transformer (ViT)–based surface encoder with geometry-aware Fourier positional encoding and Laplacian Positional Encoding (LapPE). The ViT replaces the original CNN-based encoder, enabling global attention over UV-parametric patches and producing richer surface embeddings. To better model long-range geometric correlations and topological relationships, Fourier-encoded pairwise distances and graph Laplacian eigenvectors augment node and edge features.

We trained on 10,000 synthetic CAD models from the CADSynth dataset, covering a wide variety of machining-relevant geometric configurations. Experimental results showed improved feature classification accuracy, stronger class separation, and more stable attention patterns across complex surfaces such as cylindrical features. Gains from the original BRepMFR are observed in various classes such as the Triangular Passage class, which improved from an F1 of 0.855 to 0.903 due to stronger recall.

Space Cow LLC is an applied research company with skills in software, data, and AI along with domain expertise in manufacturing, industrials, and defense. We seek to develop innovative capabilities and solutions with emerging technologies.