Using the National Information Infrastructure (NII) for monitoring, diagnostics and prognostics of operating machinery

This paper establishes distributed system architectures for electronic delivery of on line equipment monitoring, diagnostics and prognostics (MD&P) services. The MD&P information is used for predicting remaining life, and for real-time constraining of operational parameters for life extension of operating machines. Both technical and economic feasibility issues are examined. Technical feasibility analysis is supported by laboratory experiments and simulations of a reusable rocket propulsion engine and electric power plants. These experiments demonstrate substantial reductions in total accumulated damage by slight adjustments in the process variables to reduce system stress. Furthermore the results lead one to devise life extension methods for operating machinery by constraining the process variables based on load history, operational requirements and total accumulated damage of critical components. Typically, the health and monitoring of equipment is done on site, historic and diagnostic databases are archived, logistics and schedule data are available from plant management, and the dynamic models of damage and operating equipment performance under thermomechanical fatigue, creep, corrosion and wear are often proprietary and available only from vendors of equipment or research organizations. Concepts for utilizing the emerging National Information Infrastructure in meeting the computational and economic challenges of equipment life extension methods are developed. The technical vision supporting these concepts is that of electronic monitoring, diagnostic and prognostic services for electromechanical systems from specialized and generic centers over a ubiquitous information infrastructure. Necessary advances in information technology and an operational concept for supporting such a maintenance infrastructure are presented.