On the architecture of intelligent STEP-compliant CNC

STEP-NC or ISO 14649 is a new data model between CAM and CNC, currently under development by ISO TC184 SC1 and 4. Distinguished from the present CNC language (ISO 6983), the new data model includes rich information enabling feature-based programming and control for manufacturing operation. This paper aims to present a conceptual framework for an intelligent STEP-compliant CNC (called ASNC: Autonomous STEP-compliant CNC) taking ISO 14649 as an input and carrying out manufacturing tasks in an intelligent and autonomous manner. The framework is derived from the analysis of information contents of ISO 14649, and the role of CNC on the shop floor of an intelligent manufacturing system. To show the mechanism of ASNC, an operational scenario with functional details for NC milling operation is presented. The scenario illustrates that the new CNC can autonomously carry out the manufacturing tasks based on ISO 14649 and can deal with unexpected changes on the shop floor.