M. Brenner et R. Lind, WAVELET-PROCESSED FLIGHT DATA FOR ROBUST AEROSERVOELASTIC STABILITY MARGINS, Journal of guidance, control, and dynamics, 21(6), 1998, pp. 823-829
Wavelet analysis for filtering and system identification is used to im
prove the estimation of aeroservoelastic (ASE) stability margins. Comp
utation of robust stability margins for stability boundary prediction
depends on uncertainty descriptions derived from the test data for mod
el validation. Nonideal test conditions, data acquisition errors, and
signal processing algorithms cause uncertainty descriptions to be intr
insically conservative. The conservatism of the robust stability margi
ns is reduced with parametric and nonparametric time-frequency analysi
s of flight data in the model validation process. Nonparametric wavele
t processing of data is used to reduce the effects of external disturb
ances and unmodeled dynamics. Parametric estimates of modal stability
are also extracted using the wavelet transform. F-18 High Alpha Resear
ch Vehicle ASE flight test data are used to demonstrate improved robus
t stability prediction by extension of the stability boundary from wit
hin the flight envelope to conditions sufficently beyond the actual fl
ight regime. Stability within the flight envelope is confirmed by flig
ht test. Practical aspects and guidelines for efficiency of these proc
edures are presented for on-line implementation.