Parametric Representation for Geometry Variation in Digital Mechanical System

Ideal geometry is mainly represented by several parameters in traditional CAD system. Based on these parameters, ideal geometry can be dynamically constructed to build the entire CAD entity; however, the modeling of variated geometry by parameters is not included, and parametric representation for variated geometry is introduced in this paper; sets of parameters for different types of geometry variation are discussed. Based on parametric representation for variated geometry, the translation and orientation error of part that affected by the variation of geometry is calculated, the process for converting geometry error to parametric part location error is introduced.