Extrahovanie prvkov z CAD dát

V tomto príspevku je popísané extrahovanie prvkov z CAD dát. Samotná extrakcia prvkov má veľký význam z pohľadu CAPP systémov a následnej klasifikácie súčiastok. Pri klasifikácii súčiastok z rôznych hľadísk je potrebné mať informácie o prvkoch, z ktorých je súčiastka zložená. S využitím informácií o typoch, počte, rozmeroch a orientácii prvkov môžeme súčiastku následne klasifikovať. Ako vstupný CAD formát bude slúžiť súborový formát STEP, ktorý svojou štruktúrou najviac vyhovuje spracovaniu. Ako nástroj na extrahovanie prvkov bude slúžiť programovací jazyk C# 2008 s využitím princípov objektovo orientovaného programovania.Features extraction from CAD data, Vladimír Šimna, Ing., Peter Pokorný, doc. Ing., PhD., Slovak University of Technology in Bratislava, Faculty of Material science and Technology in Trnava, Institute of Production Technologies department of machining and assembly. In this paper is described features extraction from CAD data. Itself extraction has a major meaning from view of CAPP systems. Standard computer-aided design (CAD) and computer- aided manufacturing (CAM) tools are now used by industrial organizations to reduce the time and costs of product design and manufacture. It is well known that there is a functional gap between CAD and CAM, which could be bridged by computer-aided process planning (CAPP). As tool for extract features served programming language C# 2008 with using principles of object oriented programming. As input CAD data served file system format STEP AP 214. STEP-File is the most widely used data exchange form of STEP. The format of a STEP-File is defined in ISO 10303-21. The main asset of this paper is design methodology for feature extraction. The principle of this methodology is a database of rules which contain rules for features and those can be identified. The database of rules described the session between the entities that make up the element and its characteristics.If database of rules does not contain rule for feature is needed to find vertex curves of this feature and then find relation between these vertex curves. Example of component where is not defined a rule is in the figure 6. In the figure 7. can be seen an application output which contain absolute values of extracted feature. In the application, which was created to extract the elements are used principles of objectoriented programming. Through the use of these principles is easily expandable application of new rules. CAD data is used relational database managment system. The combination of these two instruments has resulted in simplyfying and streamlining the entire process of extracting required data