A STUDY OF SOME APPROACHES TO VIBRATION DATA ANALYSIS T ABRAHAMSSON T MCKELVEY and L LJUNG

Using data from extensive vibrational tests of the new aircraft Saab three di erent methods for vibration analysis are studied These methods are ERA eigensystem realization algorithm N SID a subspace method and PEM prediction error approach We nd that both the ERA and N SID methods give good initial model parameter estimates that can be further improved by the use of PEM We also nd that all methods give good insights into the vibrational modes