Abstract:
To meet the challenges of the ever-increasingly globalized manufacturing economy, open, agile, distributed, interoperable and intelligent Computer Numerical- Controlled (CNC) machine tools are one of the key enablers. Efforts to improve or even replace the current CNC data model, that is, G-codes, have been made by many researchers. This is because G-codes have become a bottleneck to achieving the afore-mentioned CNC machine tool. In recent years, the STEP-NC data model has beet). considered a promising alternative to G-code. A STEP-NC controller with Function Block (FB, otherwise known as IEC 61499) architecture has been developed in this research.
This STEP-NC controller represents the prototype of a possible future CNC system. It works with STEP-NC data and can automatically generate a part program to be executed on a machine tool. The STEP-NC controller consists of four main modules: (1) Data Input Module, (2) STEP/FB Translator, (3) Tool-Path Generator and (4) Adaptor-PB-Controller board. The system has a layered structure, making it easy to manage and extend. It unifies the functionalities of simulation and real machining under the same interface. Thanks to the use of function block technology in the form of the embedded controller software, the machining simulation is also near real-time.
The architecture has been tested through a system application, using a CNC milling machine. It has been proved that use of function block technology allows the development of an open and distributable CNC system. In addition, the controller can also support remote management and configuration, a feature that could be useful in an environment featuring multiple machine tools (for example, flexible manufacturing systems). The research work reported in this thesis has been published in two journal papers [Minhat; et al., 2009a, 2009b] and a book chapter [Minhat & Xu, 2008] and presented at two international conferences [Minhat, et al., 2008, Minhat & Xu, 2009].