Design of object-oriented database for the definition of machining operation sequences of 3D workpieces (original) (raw)
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2ND INTERNATIONAL CONFERENCE ON ENGINEERING & SCIENCE
Today's, automated process planning is becoming a widely prevalent technology in modern manufacturing systems. Feature concept is a core required to realize a fully integrated CAD/CAM system. The contents of a feature's information can simply be transferred from one manufacturing activity to another. in the last few years, Automated process planning based on features technology has become popular with its capacity to combine design and manufacturing systematically. Despite its advantages, it is still difficult to recognize and extract manufacturing features automatically from the CAD system database. This paper addressed the development of a Feature-Based Process Planning System (FBPPS) integrated with CAD systems Automatically. The developed system used the knowledge-base method to execute process planning tasks that include; process selection, process sequences, machine tool selection, tool selection, and cutting conditions. Feature recognize module based on syntactic recognition technique has been introduced using CAD database of 3D component geometry model. The process planning module has been implemented using decisionmaking procedures based on the feature recognition stage. The proposed framework was implemented on personal computers using AutoCAD 2014 as the CAD modeling system and Visual-Basic 2010 as the programming environment to build the decision-making knowledge base. A 3D CAD model of the prismatic mechanical part has been selected as a case study to examine and evaluate the FBPPS ability. The final results of the test show the success of the proposed system on manufacturing feature recognition and generate a process plan automatically.
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Process planning is one of the key activities for product design and manufacturing. Impact of process plans on all phases of product design and manufacture requires high level of interaction of different activities and tight integration of them into coherent system. In this paper we describe a model for manufacturing activities that allows integration. The framework for integration is briefly described and the manufacturing process model that considers three dimensions of planning is explained. Than an object-oriented knowledge representation approach is presented with module for parts modeling and module for generation of process plan. Description of machining process entities and their relationships with features, machines and tools are provided. The benefits of the proposed representation, which include connection with geometric model, reduced search space and alternative plan generation, are discussed. These new contributions provide for a new generation of CAPP systems that can be adapted for various manufacturing systems and can be integrated with other CIM modules.
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International Journal of Computer Integrated Manufacturing, 1997
The issues involved in forming proper knowledge representation for process planning are discussed. Following a brief review of knowledge representation schemes used in existing reported CAPP systems, the process planning function and its required knowledge are described. Then an object-oriented knowledge representation scheme is presented that allows both upstream and downstream integration of CAPP and makes it easily adaptable for interfacing with other computer integrated manufacturing (CIM) modules. Descriptions of machining process entities and their relationships with features, machines and tools are provided. The network representation of the process plan that allows for alternative plans is explained. The application of the scheme within a working process planning system prototype is brie¯y explained and supported with an example. The bene® ts of the proposed representation, which include connection with geometric model, reduced search space, and alternative plan generation, are discussed. These new contributions provide for a new generation of CAPP systems that can be easily adapted for various manufacturing systems and can be integrated with other CIM modules.
Despite over two decades of research, CAD and CAM systems are not yet completely integrated in the manufacturing environment. Feature Technology and the Object-Oriented Design represent crucial factors to develop an automated process plan system, linking CAD/CAM systems. This work intent is to recognise Manufacturing Feature which is a general entity for CAD/CAM data exchange, composed by Primary Features (Form, Precision and Technological). The paper describes an automated process plan application to the feature extraction and recognition of a 3D prismatic workpiece, using a constraint programming approach. This approach, coupled to an Attribute-Value Table AAG method, is focused on the compound features recognition task. The work exposes how constraint expressions and object-oriented classes of problem model have been formalised and give a Manufacturing Feature definition. A general-purpose CAD system (CATIA 4.1.7) and a C++ library set (ILOG Solver 3.2) has been used to implement the proposed methodology.
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The success of future automated planning systems greatly depend on further advances in two areas: (a) enhanced product modelling systems capable of answering questions posed during the planning phase; and (b) techniques for representing and manipulating planning knowledge. The work reported in this paper,investigates the useofa feature-based approach for modelling engineering parts to support the product data requirements of an intelligent planning system, employing the frame-based and rule-based knowledge representation techniques from artificial intelligence research. The approach has been applied to the domain of rotational parts.
Feature-based generation of machining process plans for optimised parts manufacture
Journal of Intelligent Manufacturing, 2012
Efficacious integration of such CAx technologies as CAD, CAM and CAPP still remains a problem in engineering practice which constantly attracts research attention. Design by feature model is assumed as a main factor in the integration effort in various engineering and manufacturing domains. It refers principally to feature clustering and consequently operation sequencing in elaborated process plan designs. The focus of this paper is on CAPP for parts manufacture in systems of definite processing capabilities, involving multi-axis machining centres. A methodical approach is proposed to optimally solve for process planning problems, which consists in the identification of process alternatives and sequencing adequate working steps. The approach involves the use of the branch and bound concept from the field of artificial intelligence. A conceptual scheme for generation of alternative process plans in the form of a network is developed. It is based on part design data modelling in terms of machining features. A relevant algorithm is proposed for creating such a network and searching for the optimal process plan solution from the viewpoint of its operational performance, under formulated process constraints. The feasibility of the approach and the algorithm are illustrated by a numerical case with regard to a real application and diverse machine tools with relevant tooling. Generated process alternatives for complex machining with given systems, are studied using models programmed in the environment of Matlab software.