Interpreting the Engineer's Sketch: A Picture is Worth a Thousand Constraints

Abstract

We describe a program called SKETCHIT that transforms a single sketch of a mechanical device into multiple families of newdesigns. To "interpret" a sketch the programfirst determines how the sketched device should have worked, then derives constraints on the geometryto ensure it works that way. The programis based on qualitative configuration space (qc-space), a novel representation that captures mechanical behavior while abstracting awaythe particular geometry used to depict this behavior. The program employsa paradigm of abstraction and resynthesis: it abstracts the initial sketch into qc-space then mapsfrom qc-space to newgeometries.