A review of STEP-NC compliant CNC systems and possibilities of closed loop manufacturing

Abstract

A new programming interface, ISO14649, named STEP-NC, has been introduced recently to overcome the drawbacks of the conventional CNC system. Enhanced machining flexibility, interoperability, and adaptability are the key features of this new programming strategy. STEP-NC technology is based on object-oriented concepts and considers machining processes rather than tool motions as in ISO 6983 for machine tool operation. As such, high level machining features and machining parameters are transferred to the CNC controller, which are eventually used for generating axis movements and other operations. The bidirectional data communication facility of this new strategy enables last minute shop floor level modifications of machining operations at the controller level and establishes a communication pathway to feed major modifications, if required, back to the CAD level as well. Accordingly, the new programming interface allows seamless integration in the CAD/CAM/CNC chain and paves the way for Closed Loop Manufacturing facilities. Most CNC controller vendors have not released STEP-NC compliant controllers yet. Therefore, researchers are developing Open Architecture Control systems to execute STEP-NC and operate CNC machines. This paper reviews research and development of STEP-NC controllers in the last decade and the capabilities of Closed Loop Manufacturing with STEP-NC based systems.