Date of Award

12-1993

Document Type

Thesis

Degree Name

Master of Science in Astronautical Engineering

Department

Department of Electrical and Computer Engineering

First Advisor

Peter S. Maybeck, PhD

Abstract

Dithering techniques for enhancing uncertain parameter identification with moving-bank Multiple Model Adaptive Estimation MMAE and Control MMAC algorithms are analyzed in this thesis. The dithering techniques and multiple- model adaptive algorithms are applied to the SPICE 2 flexible space structure. The dithering techniques studied include purposefully constructed square wave, sine wave fixed and swept frequency and wide-band noise wave forms. Purposeful rigid-body slew commands are also used in order to excite the structures flexible bending modes. Dither inputs into the structure are performed in an effort to enhance the open-loop identifiability of the uncertain parameter, namely a scalar multiplier on the undamped natural frequencies of the flexible bending modes. Correct identification of this parameter enables the MMAE and MMAC algorithms to quell any vibrations induced into the structure, in the face of varying parameter values. The results of this study indicate that purposefully constructed dither signals do enhance parameter identification significantly. The parameter identification enhancement due to rigid-body slew command input was shown to be less effective than that with sinusoid and wide band noise dither inputs, however.

AFIT Designator

AFIT-GA-ENG-93D-01

DTIC Accession Number

ADA274132

Comments

The author's Vita page is omitted.

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