Abstract
This paper proposes a method of defining similarity between sketches based on physical quantity and geometry. The purpose of this study is to enable case-based design aid using this similarity : designers can retrieve and consult the relevant sketches to their current design problem, or extract sharable design knowledge by classifying accumulated sketches, from the viewpoints of behavior and structure. First, we introduce methods of describing and recording design concept sketches by physical quantities and geometries. Then, we introduce a similarity definition of sketches consisting of drafting elements. Similarity between pair of drafting elements is defined by combining individual similarity for each attribute, and then similarity between sketches is defined based on the drafting element similarity. We implemented the proposed method as a computer program written in Common Lisp, and examine its efficacy and possibility by applying the idea to some simple examples.
