الفهرس | Only 14 pages are availabe for public view |
Abstract As STEP-NC grows as the new technique for programming CNC machine tools, the traditional interface so called M & G code (ISO 6983) commonly used for CNC since 1950s is about to be obsolete. Establishing, developing and implementing STEP-compliant CAD/CAM/CNC system based on the new data model is drawing worldwide attention. This research focuses in two points. Firstly, a comparison between the two programming methods of CNC machine tools, namely, the G and M codes and the new technique of programming CNC machine tools known as STEP-NC which is a new interface for the CAD-CAM-CNC chain formalized in (ISO 14649 and ISO 10303 AP238). Secondly, a conversion system between Step-NC and G-code. By this automatic conversion the problem of legacy code -preserved by companies when STEP-CNC becomes widely available- has been overcome. Thesis Structure The thesis consists of six chapters: Chapter 1: Introduction Chapter 2: A comparison between the current technique and the new one is discussed together with a case study to show the shortcomings of the G-code, and then a literature review is made about the new data model. Chapter 3: A theoretical background of the new technique is discussed with a detailed description of the ISO10303, the ISO 14649, the STEP-NC file structure, and finally, the design considerations, functional architecture, and implementation architecture of a STEP-compliant CNC software are discussed together with an application that show in details the steps of producing a part program based on the new technique. Chapter 4: The design considerations and the functional architecture of the recommended conversion system between the current technique and the new one are discussed. This chapter focuses on the conversion from G-code to STEP-NC. The information that can be extracted from a G-code part program is clarified with the information necessary to form a STEP-NC part program. The procedures of conversion are illustrated supported with a case study. Chapter 5: This chapter focuses on the conversion from STEP-NC to G-code. The procedures of conversion are illustrated supported with a case study Chapter 6: The main conclusion of the research is presented, and the recommendations for future work are discussed. |