XML-based Data Processing in Network Supported Collaborative Design

In the course of network supported collaborative design, the data processing plays a very vital role. Much effort has been spent in this area, and many kinds of approaches have been proposed. Based on the correlative materials, this paper presents extensible markup language （XML） based strategy for several important problems of data processing in network supported collaborative design, such as the representation of standard for the exchange of product model data （STEP） with XML in the product information expression and the management of XML documents using relational database. The paper gives a detailed exposition on how to clarify the mapping between XML structure and the relationship database structure and how XML-QL queries can be translated into structured query language （SQL） queries. Finally, the structure of data processing system based on XML is presented.

Study on Distributed Knowledge Information System for Product Design

To overcome the limitations of commercial CAD and handbook form of knowledge expression, the Distributed Knowledge Information System (DKIS) for product design is proposed. The structure of DKIS and the key issues in its implementation are introduced; the method of knowledge store and transfer of DKIS is discussed. The mechanism of knowledge representation, acquisition and utilization, based on Internet network, is achieved. Based on the concept of function driven, integrated Artificial Neural Networks and Active Server Pages techniques, transplanting the trained ANN into DKIS system, a new method for retrieving knowledge in DKIS over Internet is achieved. Finally, a prototype of DKIS is developed to demonstrate the feasibility of the structure and constructional method of DKIS. The work pro-vides a scheme for speed knowledge acquisition and shortens the cycle of product development.

Feature Analysis of STEP Application Protocol and its Application

This paper uses semantic data modelling and CAD/CAPP/CAM integration to analyze the features defined in the STEP AP214, its characteristics of definition and distribution, and its influence on the complexity of CAD/CAPP/CAM application integration. A framework is developed for applications of CAD/CAPP/CAM integration based on the STEP to reduce the complexity of integration implementation. Two application program interfaces (API), namely, application protocol API and application API, are developed. The frameworks hierarchy structure and the application program interfaces between the layers make the integration of applications easier.

STEP AP 242 Managed Model-based 3D Engineering:An Application Towards the Automation of Fixture Planning

Fixture design and planning is one of the most important manufacturing activities, playing a pivotal role in deciding the lead time for product development. Fixture design, which affects the part-quality in terms of geometric accuracy and surface finish, can be enhanced by using the product manufacturing information(PMI) stored in the neutral standard for the exchange of product model data(STEP) file, thereby integrating design and manufacturing. The present paper proposes a unique fixture design approach, to extract the geometry information from STEP application protocol(AP) 242 files of computer aided design(CAD) models, for providing automatic suggestions of locator positions and clamping surfaces. Automatic feature extraction software "FiXplan", developed using the programming language C#, is used to extract the part feature, dimension and geometry information. The information from the STEP AP 242 file is deduced using geometric reasoning techniques, which in turn is utilized for fixture planning. The developed software is observed to be adept in identifying the primary, secondary, and tertiary locating faces and locator position configurations of prismatic components. Structural analysis of the prismatic part under different locator positions was performed using commercial finite element method software, ABAQUS, and the optimized locator position was identified on the basis of minimum deformation of the workpiece.The area-ratio(base locator enclosed area(%)/work piece base area(%)) for the ideal locator configuration was observed as 33%. Experiments were conducted on a prismatic workpiece using a specially designed fixture, for different locator configurations. The surface roughness and waviness of the machined surfaces were analysed using an Alicona non-contact optical profilometer. The best surface characteristics were obtained for the surface machined under the ideal locator positions having an area-ratio of 33%, thus validating the predicted numerical results. The efficiency, capability and applicability of the developed software is demonstrated for the finishing operation of a sensor cover – a typical prismatic component having applications in the naval industry, under different locator configurations.The best results were obtained under the proposed ideal locator configuration of area-ratio 33%.