Recently, the modelling of variation propagation in multistage machining processes has drawn significant attention. In most of the recently developed variation propagation models, the dimensional variation is determined through kinematic analysis of the relationships among error sources and dimensional quality of the product, represented by homogeneous transformations of the actual location of ...

To ensure the robustness of geometric tolerancing in collaborative design, a multi-view tolerance data representation is needed as well as a multi-level representation. The goal of multi-level representation is to detail the tolerances as the knowledge of the product progresses during its development. After a brief discussion, IPPOP product model and GeoSpelling tolerance model are chosen as ba...

Under NSF sponsorship, we are developing a Solid Interchange Format (SIF) with which descriptions of desired parts can be transmitted efficiently and unambiguously from a designer to competing fabricators. SIF is a terse, human readable ASCII format providing a processand resolution-independent description of the desired shape. It also explicitly captures some aspects of the part topology and o...

Manufacturing tolerancing is intended to determine the intermediate geometrical and dimensional states of the part during its manufacturing process. These manufacturing dimensions also serve to satisfy not only the functional requirements given in the definition drawing, but also the manufacturing constraints, for example geometrical defects of the machine, vibration and the wear of the cutting...

Machining accuracy can be greatly increased through the use of highresolution position sensors, calibration of machine tool or robot components, and other measures which serve to improve the machine’s positional response to part programs. Unfortunately, much of the inaccuracy in finished parts is due to dynamically varying quantities, such as tool wear, chatter, or thermal expansion; random err...

The optical, noncontact stereovision system and data analysis procedure are developed for the measurement of porous foams. The stereovision measurement system has demonstrated the capability to capture both the micro-scale features and the macro-scale shape of both the open-cell and closed-cell porous foams. A computational procedure, denoted as the grid method, is developed to identify represe...

Mixed-signal multidomain systems present a challenge for computer-aided design tools. Optical and electronic simulation tools are available as separate entities. However, to date, successful system-level cosimulation has not been implemented, leading to expensive refabrication. We present a unique system-level simulation tool for mixed electrooptical systems. We apply our tool Chatoyant to the ...

System-level packaging is one of the critical issues that need to be addressed for free space optical interconnections (FSOI) to become useful in desktop systems. The performance of FSOI, e.g., in terms of system bit-error rate, is greatly affected by misalignments in the optical system. Therefore tolerancing, i.e., the ability to analyze and predict the effects of misalignments in the system, ...

We develop an architecture for a product master model that federates CAD systems with downstream application processes for di erent feature views that are part of the design process. The architecture addresses especially the need to make persistent associations of design information with net shape elements. Moreover, the design respects the need of commercial CAD systems (and of downstream appl...