H^∞ parameter identification for inflight detection of aircraft icing: The time-varying case

This paper considers inflight parameter identification of aircraft flight dynamics in the context of an ice management system. In particular, an H^∞ parameter identification algorithm is evaluated in terms of detecting an aircraft icing event using a noisy state measurement. Previous studies had addressed identification over several seconds during a maneuver, utilizing the excitation due to the maneuver and assuming a time-invariant parameter. This paper addresses identification over longer periods, where excitation is provided only by turbulence, and parameter variation must be considered. Simulation results demonstrate that for moderate turbulence, the time-varying H^∞ algorithm provides a timely and unambiguous icing indication.