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Analysis of uncertainty in force balance calibrationIn order to reduce errors encountered in the measurement and identification of loads using force balances, a third-order forward polynomial relation between loads and output voltages is proposed. This full third-order model represents an alternative to the second-order model currently in use at NASA Langley Research Center (LaRC) and many other installations worldwide. The new model requires the identification of 84 coefficients (including the 28 used presently) for each of the six outputs. The existing LaRC calibration loading sequence is insufficient for identification of many of these 504 coefficients because critical three-load combinations are absent. Accordingly, a new loading sequence that permits the identification of all 504 coefficients has been developed and is described fully. It is apparent from numerical tests that the new third-order model is clearly superior to second-order models in the presence of small amounts of random measurement noise, assuming that there are indeed higher-order interactions between loads. As the amount of noise increases, however, a third-order model becomes less attractive due to its ability to match the noise itself more faithfully than a second-order model. Numerical results suggest that the transition occurs when the magnitude of random noise becomes of the same order as that of the physical higher-order interactions.
Document ID
19960020764
Document Type
Conference Paper
Authors
Bursal, Faruk H.
(Virginia Polytechnic Inst. and State Univ. Blacksburg, VA United States)
Date Acquired
August 17, 2013
Publication Date
December 1, 1995
Publication Information
Publication: The 1995 NASA-ODU American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program
Subject Category
Numerical Analysis
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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IDRelationTitle19960020755Analytic PrimaryThe 1995 NASA-ODU American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program
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