| 1. PrefaceNowadays, the global competition in manufacturing field has become more and more drastic, how to increase the overall competitiveness of an enterprise has become one of the most critical problems, which confronts the modern manufacturers. In order to improve the comprehensive competence of an enterprise, many new manufacture paradigms, such as Computer Aided Design(CAD),Computer Aided Manufacture(CAM),Computer Aided Process Planning(CAPP) ,Computer Integrated Manufacturing System(CIMS) and Concurrent Engineer (CE) and Virtual Manufacturing (VM) etc. , have been proposed and studied by many researchers. All of the paradigms mentioned above need product data to be exchanged and shared. The superiority of system should be evaluated by its veracity for exchanging especially in the case of various systems. So the Product Data Exchange Standard is the basis to implement these paradigms.The technology of Product Data Exchange is a vital research item in the field of integrated manufacturing and automation. Its application is not only in various management layers but also in the manufacturing layer. Computer Numeric Control (CNC) is an important method for implementation of integrated manufacture. With the development of automatization, CNC also need auto-coding –Automatically Programmed Tool (APT). The input of APT is all kinds of 3D solids, which come from various 3D shaped platform. The 3D solid should be added processing information at the level of CAPP or APT as itself has no manufacturing information. So the efficient exchanging way for product related data among various systems becomes more and more important in CNC field. The goal of this paper is to provide an efficient approach for exchange and share of product related data among various system — Technology of 3D solid feature extraction and model regeneration based on STEP. The application scope includes CAPP and APT, etc.2. STEP and application in CIMThe Standard for the Exchange of Product Model Data (STEP) is a complete set of ISO's norm, which includes product data exchange and share of the complete product life cycle. The aim of STEP is to provide a neutral form independent on any concrete system, which can describe the whole product related data and keep the integrality of data in product life cycle.The EXPRESS is a powerful formalize-describing language in STEP, which almost can describe all objects and action in being and map to C/C++. STEP provides the interface for product related data exchange and share, which also guarantee the deep development to CIM. With the development of CIM, the platform based on STEP can provide the function such as 3D solid model browsing,finite analysis for 3D solid etc.The traditional application of STEP is ST-Developer and SDAI provided by Step Tools, which is available for large manufacturing system that needs a great deal of planning information such as CAPP. SDAI is an interface, which provides an efficient way for STEP software but cost large. In this paper, there is another way for STEP application that starts with the STEP neutral file directly. We put forward a method for 3D solid feature extraction and exploit a feature extraction system – ST3D for browsing 3D solid feature based on STEP. The feature extraction system is implemented using object-oriented modeling principle and C++ programming language. 3. The implement of 3D solid feature extraction and model regeneration based on STEPBased on the theory of STEP, we find the advantage of STEP neutral file and its availability for product related data exchange and share in the whole product life cycle. We can extract the geometry feature from STEP file by the neural mechanism. As for sustaining with STEP in most 3D modeling systems, we also can develop a platform for extraction and re-modeling of 3D solid that comes from various 3D modeling systems. The platform can be applied in many occasion such as feature recognizing, regeneration of Planning Plan, etc., This paper gradually illustrates the application of STEP a...
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