Abstract: The concept of composite configuration space (CCS) for mechanical assembly is put forward and the related properties and expression methods are studied. CCS is a union of motion parameter domains of the mechanisms with variable topologies formed by varying part surface-surface contact relationships in a mechanical assembly. The study is concentrated on the natural connections from the part contact states as well as their transitions in assembly to the different motion parameter domains and their adjacency relations in CCS. By means of the concepts from topology, some useful insights to the classifications and properties of CCS are provided. In addition, a direct expression method is presented, in which, motion parameter domains are first represented by a direct product of a sequential of intervals with variable bounds after the parts’ locations are parameterized in some order, and then a CCS is constructed by connecting the domains along their boundaries with parameter mappings. Finally, some examples of CCS are given. The above-mentioned work lays a foundation for further research on mechanical CAD model checking based on identifying the model’s behavior envelope.

Key words: Assembly model, Configuration space, Mechanisms with variable topologies, Model checking, Workspace