Fog Computing-Based Cyber-Physical Machine Tool System

As one kind of significant manufacturing equipment, computer numerical control (CNC) machine tools have to be endowed with new functions to meet the requirements of processing devices in the era of "Industry 4.0." Inter-connection and intelligence are the fundamental characteristics of CNC machine tools in this era. To make CNC machine tools be more accessible and promote them to a higher level of intelligence, this paper presents a new architecture of CNC machine tools based on a cyber-physical system and fog computing, named as a fog computing-based cyber-physical machine tool system (FC-CPMTS). The definition, functions, and hierarchical structure of the FC-CPMTS are described respectively. CNC machine tools, cyber space, and human beings are connected closely through sensing, computing, communicating, and controlling in the FC-CPMTS. The application of fog computing enhances autonomy and collaboration of CNC machine tools. It also reduces network traffic and calculation workload of the cloud platform in the FC-CPMTS. To demonstrate the rationality and feasibility of the FC-CPMTS, an FC-CPMTS for a heavy-duty CNC machine tool is taken as a case study. The result shows that autonomy, intelligence, interconnection, and interoperability of the CNC machine tool are improved.