Ambike A., ’Real-time operating environment for networked control systems

Abstract—This paper presents the development of a novel real-time operating environment for networked control systems (NCSs). An open-loop unstable magnetic-levitation (maglev) test bed was constructed and used to develop an NCS with real-time applica-tion interface (RTAI). A client–server architecture on a local-area network was developed with the network communication based on the user datagram protocol. The control loop of our NCS is closed over the network. This NCS structure gives the best flexi-bility and has significant economical merits. The implementation of an event-driven server and a time-driven client presented in this paper facilitates a simple timing scheme that does not require clock synchronization between the client and the server. A novel prediction scheme with a multiple-step-ahead control-signal gen-erator is used to maintain system stability in the presence of ex-cessive time delays and data-packet losses in the communicatio