Stability analysis of upset recovery methods for electromagnetic interference

Presents a tool to analyze the effect of error recovery systems on closed-loop flight control systems. In particular, the paper develops closed-loop models and analyzes the mean-square stability effect of error recovery rollback, reset, and cold restart systems in digital control systems. The error recovery mechanisms are triggered by transient or intermittent faults which could be caused, for example, by high intensity electromagnetic radiation. The tool is illustrated by analyzing a stabilizing controller for the longitudinal dynamics of the AFTI/F-16 aircraft. This example compares different recovery methodologies by determining the minimum interarrival spacing between upsets which maintains closed-loop mean-square stability.