Autonomous Coordinated Operations Response Network for Fault Detection, Isolation, and Response

The Autonomous Coordinated Operations Response Network (ACORN) is a state-based approach to FDIR built atop advanced sequencing capabilities currently available in the marketplace. ACORN offers a standardized method for designing, implementing, and running fault protection across disparate spacecraft. The approach uses graphical representations of state machines which manage various subsystems of the spacecraft. The runtime version of state machines coordinate together using guard conditions on transitions. These state machines identify and respond to faults at the component, intermediate, and system levels. Identification of fault conditions is based on telemetry values and sequence global variable values written to by flight software during runtime.The state-based design of ACORN enforces flight rules and other requirements, operating the spacecraft in a constraint-oriented manner. Responses take the form of spacecraft commands and sequence block invocations, which are implementations found on all spacecraft. Since ACORN runs onboard the spacecraft, it has immediate access to all of the telemetry necessary to detect faults.ACORN specifications are mission-independent. If a mission lacks a sufficiently powerful sequencing capability to implement the specification, the ACORN process is still extremely useful as a high-level design specification for custom components to be implemented, and allows a standardized capability to be used. Should the target mission feature a sequencing capability with an ACORN translation tool, the specification is automatically translated into an executable set of sequencing components that fully implement the desired detections and capabilities.Advantages: 1. cross-mission 2. cross-platform 3. inheritable 4. efficient specification 4. fast response times (on board) 6. emergent behavior 7. low cost 8. transparent 9. layered interfaces 10. iterative processnbsp;