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Linear system identification via backward-time observer modelsPresented here is an algorithm to compute the Markov parameters of a backward-time observer for a backward-time model from experimental input and output data. The backward-time observer Markov parameters are decomposed to obtain the backward-time system Markov parameters (backward-time pulse response samples) for the backward-time system identification. The identified backward-time system Markov parameters are used in the Eigensystem Realization Algorithm to identify a backward-time state-space model, which can be easily converted to the usual forward-time representation. If one reverses time in the model to be identified, what were damped true system modes become modes with negative damping, growing as the reversed time increases. On the other hand, the noise modes in the identification still maintain the property that they are stable. The shift from positive damping to negative damping of the true system modes allows one to distinguish these modes from noise modes. Experimental results are given to illustrate when and to what extent this concept works.
Document ID
19920020971
Acquisition Source
Legacy CDMS
Document Type
Technical Memorandum (TM)
Authors
Juang, Jer-Nan
(NASA Langley Research Center Hampton, VA, United States)
Phan, Minh Q.
(Lockheed Engineering and Sciences Co. Hampton, VA., United States)
Date Acquired
September 6, 2013
Publication Date
June 1, 1992
Subject Category
Structural Mechanics
Report/Patent Number
NAS 1.15:107632
NASA-TM-107632
Report Number: NAS 1.15:107632
Report Number: NASA-TM-107632
Accession Number
92N30214
Funding Number(s)
PROJECT: RTOP 590-14-21-01
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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