Integrated Model-Based Fault-management System Design

An Integrated Model-based Fault-management System Design (IMFSD) environment for current-generation and future high-autonomy space systems is developed, which integrates and documents in one platform framework Fault Management (FM) design processes, models and products. The IMFSD covers FM requirements definition, and design specification, analysis, validation-and-verification (V&V), and documentation, enabling the connection of the associated processes and models to the corresponding elements of the host space system model-based design.The integration of FM developmentlife-cycle processes is achieved by means of a “design development, documentation, and assurance case” (D3AC) logic structure hosted within the IMFSD software platform, which provides active connectivity among all elements of the FM design, and with the evidences produced to demonstrate compliance with concept-of-operations (ConOps) and requirements.In view of expected spacecraft-autonomy evolutions for which expanded FM operational capability and analytics will be needed, the IMFSD, in addition to established FM models like Fault Tree Analysis (FTA) and Failure Modes and Effects Analysis (FMEA), includes, or links to, logic-dynamic models – e.g., Dynamic Flowgraph Methodology (DFM) and Markov Cell-to-Cell Mapping Technique (Markov-CCMT) – that can extend FM analysis into the time-dependent-logic domain. Other potentially applicable state-of-the-art models from the field of machine-learning, like Bayesian Belief Networks (BBN), Neural Networks (NN), Fuzzy Logic (FL, and Influence Diagrams (ID), are also evaluated for evolutionary inclusion in the IMFSD.Once demonstrated for NASA applications, the IMFSD will be transferable to the design of FM for the high-autonomy commercial systems that are presently being developed in the aeronautical and transportation fields. This provides a path for commercialization efforts that will be initiated during execution of the Phase I development project.