Development and optimization of an MTConnect based edge computing node for remote monitoring in cyber manufacturing systems

In recent years, MTConnect has emerged as a potential communication standard for cyber manufacturing (CM) domain by establishing remote monitoring of manufacturing processes through XML based data reporting structure and RESTful services. This paper presents the development and optimization of an MTConnect based edge computing node in service-oriented CM systems by utilizing data caching and processing at the edge. Unlike MTConnect agents, proposed MTConnect Edge Nodes (MENs) not only convert collected machining data to XML messages and host RESTful services, but also perform as an edge node by adopting a “hold-until-changed” approach for deciding which data to store and by keeping tracks of previously transmitted data to its clients to determine which data to transmit to whom and when. The primary objective is to minimize data storage requirements and cost while enabling rapid transmission and low bandwidth usage without increasing information loss. This paper describes the architecture of an MEN and its data caching and transmission strategies in details. Experiments were conducted in a CM testbed with three machine tools, raspberry pis hosting MENs and MTConnect agents, and two client applications to evaluate MEN’s performance with respect to the conventional approach. Results showed 96.2 percent reduction in required storage size with 52.5 percent reduction in average communication latency and 99.5 percent reduction in average message size for proposed MEN in different manufacturing scenarios.