Available online at www.sciencedirect.com 2212-8271 © 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of 13th CIRP conference on Computer Aided Tolerancing doi:10.1016/j.procir.2015.04.036 Procedia CIRP 27 (2015) 10 – 15 ScienceDirect 13th CIRP Conference on Computer Aided Tolerancing Tolerance Analysis of rotating Mechanism based on Skin Model Shapes in discrete Geometry B. Schleich a,* , S. Wartzack a a Chair of Engineering Design KTmfk, Friedrich-Alexander-University Erlangen-N¨ urnberg, Martensstraße 9, 91058 Erlangen, Germany ∗ Corresponding author. Tel.: +49-(0)9131-85-23220; fax: +49-(0)9131-85-23223. E-mail address: schleich@mfk.fau.de Abstract Geometric deviations are inevitably observable on every manufactured workpiece. These deviations affect the function and quality of mechanical products and have therefore to be controlled by geometric tolerances. Computer-aided tolerancing aims at supporting design, manufacturing, and inspection by determining and quantifying these effects of geometric deviations on the product quality and the functional behaviour. However, most established tolerance representation schemes imply abstractions of geometric deviations and are not conform with the standards for geometric dimensioning and tolerancing. These limitations led to the development of a Skin Model inspired framework for the tolerance analysis, which is based on a representation of non-ideal workpieces employing discrete geometry representation schemes, such as point clouds and surface meshes. In this contribution, this Skin Model inspired framework for computer aided tolerancing is extended to systems in motion and applied to the tolerance analysis of rotating mechanism with higher kinematic pairs. For this purpose, the generation of non-ideal part representatives, as well as their processing with algorithms for registration and computational geometry are highlighted. Finally, the results are visualized and interpreted. The procedure as well as the simulation model itself are shown in a case study of a disk cam mechanism. c  2015 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the organizing committee of 13th CIRP Conference on Computer Aided Tolerancing. Keywords: Skin Model; Tolerance Analysis; Rotating Mechanism; Discrete Geometry; Computational Geometry. Nomenclature CAD Computer Aided Design CAT Computer Aided Tolerancing (F)KC (Functional) Key Characteristic GPS Geometric Product Specification and Verification ISO International Organization for Standardization ICP Iterative Closest Point 1. Introduction Geometric deviations are inevitably observable on every manufactured workpiece. These deviations affect the functional compliance and quality of mechanical products and have there- fore to be controlled by geometric tolerances. Thus, toleranc- ing is a key activity in order to realize high quality mechanism manufactured at moderate costs. It is a responsible task, which requires a high level of expertise. Computer-aided tolerancing (CAT) aims at supporting design, manufacturing, and inspec- tion by determining and quantifying the effects of geometric deviations on the product quality and the functional behaviour. In the context of CAT, the representation of geometric devia- tions is still a key issue in tolerance simulation modelling, since most established tolerance representation schemes imply ab- stractions of geometric deviations. Many models for the repre- sentation of geometric deviations, which are subsumed as vari- ational geometry approaches and used for the displacement ac- cumulation, and for the representation of geometric tolerances, which are referred to as tolerance zone models and used for the tolerance accumulation, have been proposed [1,2]. However, most of these models only consider translational and rotational defects of part features [3,4]. Furthermore, many of the avail- able tolerance simulation tools are not conform with the stan- dards for geometric dimensioning and tolerancing [5]. These limitations led to the development of a Skin Model inspired framework for the tolerance analysis [6,7], which is based on a representation of non-ideal workpieces employing discrete geometry representation schemes, such as point clouds and surface meshes. These workpiece representatives are re- ferred to as Skin Model Shapes, since they can be interpreted as outcomes of the Skin Model as a basic concept in the stan- dards for geometric product specification and verification. In © 2015 The Authors. Published by Elsevier B.V This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of 13th CIRP conference on Computer Aided Tolerancing