Hybrid Tolerance Representation of Systems in Motion

Abstract

Dimensional management deals with the fact that the real geometry of every manufactured part deviates from its ideal shape. To evaluate the effects of these deviations tolerance analysis, which are often based on vectorial models, are carried out. Nevertheless the use of vectorial models has one major disadvantage – they cannot adequately represent form deviations. As a consequence new concepts of representations based on the GPS’ Skin Model have been established. Since the use of Skin Model Shapes (SMS) is time-consuming and does not always offer advantages over vectorial models, the Hybrid Tolerance Representation (HTR) which combines the advantages of vectorial and discretely represented tolerances is introduced in this paper. The HTR is based on a classification of the contact situation of the cinematic chain into lower and higher kinematic pairs. Based in this classification all higher kinematic pairs are going to be represented by SMS whereas lower pairs, are represented by vectors. Besides the simulation of the contact situation of all higher kinematic pairs the coupling of vectorial and discrete geometry representations is a challenge. The practical implementation of the presented method is shown on an X-ray shutter.