Abstract. This paper presents an algorithm for efficiently recognizing and determining the convexity of an edge blend feature. The algorithm first recognizes all of the edge blend features from the Boundary Representation of a part; then a series of convexity test have been run on the recognized edge blend features. The novelty of the presented algorithm lies in, instead of each recognized blend feature is suppressed as most of researchers did, the recognized blend features of this research are gone through a series of convexity test before this blend features are used in automatic machining features recognition. A new graph-based method is also introduced with taking account of this edge blend features used in automatic machining feature recognition. This study has contributed to CAD/CAPP integration based on STEP standard in the life cycle of product development.

Manufacturing is one of the main source of income for a developing country, like Malaysia. Start from the beginning of need in the market, a new concept of product is created. From the initial idea based on a need, this idea is hard to be understood if not presented in any form of drawing or prototype. So, computer-aided design (CAD) has the greatest role in helping to visualise the initial concept of a design with presenting the idea in a graphical view. However, this type of data cannot be used directly for the manufacturing process and normally intervention of human effort is needed to define all the manufacturing features from the component drawing again. This work is laborious if not assisted by computer technology. As a result, this paper aims to design a system and database which has the ability to extract geometrical features from drawings and identify all the manufacturing features which is useful for manufacturing process. This project takes a neutral drawing format, ISO 10303-203, as the input of the system. Then, a mechanism which consists of manufacturing feature extraction and feature recognition will be implemented and lastly, a new form of manufacturing feature-based data, ISO 10303-224 will be acquired for the subsequent manufacturing process.

Computer technology has become a very important element in an advanced manufacturing system. The good and systematic data model for the exchange of manufacturing information between different stages of development of product life cycle is paramount to ensure the product is manufactured and delivered to the market successfully. As a result, ISO 10303, an international standard, or well known as Standard for Exchange of Product Model Data (STEP) is not just for providing a neutral data format within the heterogenous CAD systems, its functionality has extended to the whole life cycle of product. STEP Part 21 is the first implementation method from EXPRESS modelling language and implemented successfully as neutral product data to integrate heterogeneous CAD platform. However, this CAD STEP Part21 text file is hardly to be applied in manufacturing processes since it consists of purely geometrical and topological data. In this research, a nonprocedural approach is presented to translate the EXPRESS language model of STEP CAD data into a new product database system model. A new nonprocedural approach of data enrichment and automated machining feature recognition is proposed and implemented on this newly developed product database system and provide a solution for the interrelated tasks of automated machining feature recognition: (1) extraction of geometrical feature from STEP CAD model data of the part (2) formation of part representation suitable for form feature identification (3) matching of form features. This paper proves the validity of this newly developed product database system by translating STEP Part21 file from a commercial CAD system to database system format, data enrichment, performing automated machining feature recognition and lastly generating STEP standard data according to AP224 for supporting STEP based process planning and manufacturing applications.

Abstract. This paper presents details of developing a STEP-compliant database system which has the ability to support the implementation of product life cycle applications. Currently, most of CAD systems have the ability to generate geometrical and topological data in STEP file format. This developed STEP-compliant database management system has shown its ability to convert this generated STEP file format to database format, which is more suitable for the downstream of manufacturing applications, especially for process planning and machining processes based on STEP.

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