A design approach for constructing engineering scenario maps

Abstract

We present a cognitively based design approach for the staged construction of a high level linguistic-visual map useful for engineering scenario analysis. This map, which we call a Three Dimensional Conceptual Thematic Map (3D-CT Map), is a linkage of a 3-Dimensional geometric Map (3D-Map) and a semantic net which we have called a Conceptual Thematic Map (CT-Map). The 3D-CT Map is an attempt to specify what is in the environment, where it is, and what is happening to it. The CT-Map component is derived by combining information from two explicit linguistic levels, syntax and semantics. It consists of recursively nested semantic structures linked by thematic roles. The 3D-Map component is derived by combining the information from two explicit visual levels, the 2 1/2 D sketches (which correspond to standard engineering drawings) and three dimensional shape models. The result of these visual combinations is the 3D-Map which shows the object centered three dimensional geometric component of the scenario. Annotating the 3D-Map with selected cross references to the CT-Map constitutes the 3D-CT Map. The theoretical bases of the 3D-CT Map rest on the combined insights of contemporary vision and linguistics researches, principally Ray Jackendoff and David Marr. These linguistic and vision insights are founded on a representationalist view of human understanding and action that includes the formal recognition, analysis, and constructive representation of autonomous levels of mental information structures. Each level of representation has its own set of primitives, well-formedness rules, and links to other levels via inter and intra level correspondence rules. At an even more fundamental level, these insights are in consonance with a view of the human mind/brain as a biological information processor. We illustrate this cognitive design approach by constructing a 3D-CT Map from a scenario drawn from the spatial domain of Numerical Control Part Programming. The inputs to the derivation consist of engineering drawings, a natural-language scenario description of the procedure to be carried out, and the experience of the part programmer. The outputs from the scenario analysis process are: syntactic parse trees, semantic structure graphs, annotated semantic structure graphs (i.e., the CT-Map), 2 1 2 D sketches of the geometry of the scenario (i.e., engineering drawings), a 3D-Map of the scenario geometry, and finally, a synthesized map of the scenario that links these components together i.e., the Three Dimensional Conceptual Thematic Map.