AUTOMATIC IDENTIFICATION OF GEOMETRIC CONSTRAINTS IN MECHANICAL ASSEMBLIES

Mechanical assemblies of manufactured components involve sets of relat ions between mating surfaces and functional characteristics. Component s must fit together to assemble and function properly, placing constra ints on the allowable values of the component dimensions. Kinematic mo tion of the components is often necessary, resulting in other geometri c constraints. Identification of constraints in models of mechanical a ssemblies is necessary for simulations of the effects of dimension and tolerance changes. This paper presents techniques for the automatic i dentification of such constraints in computer models of three-dimensio nal assemblies with nonorthogonal contacts between component surfaces and kinematic joints. The approach relies on a graph-based representat ion of the assembly. Search algorithms for identifying assembly constr aints in this graph are presented. (C) 1998 Elsevier Science Ltd. All rights reserved.