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LPV Modeling of a Flexible Wing Aircraft Using Modal Alignment and Adaptive Gridding MethodsOne of the earliest approaches in gain-scheduling control is the gridding based approach, in which a set of local linear time-invariant models are obtained at various gridded points corresponding to the varying parameters within the flight envelop. In order to ensure smooth and effective Linear Parameter-Varying control, aligning all the flexible modes within each local model and maintaining small number of representative local models over the gridded parameter space are crucial. In addition, since the flexible structural models tend to have large dimensions, a tractable model reduction process is necessary. In this paper, the notion of s-shifted H2- and H Infinity-norm are introduced and used as a metric to measure the model mismatch. A new modal alignment algorithm is developed which utilizes the defined metric for aligning all the local models over the entire gridded parameter space. Furthermore, an Adaptive Grid Step Size Determination algorithm is developed to minimize the number of local models required to represent the gridded parameter space. For model reduction, we propose to utilize the concept of Composite Modal Cost Analysis, through which the collective contribution of each flexible mode is computed and ranked. Therefore, a reduced-order model is constructed by retaining only those modes with significant contribution. The NASA Generic Transport Model operating at various flight speeds is studied for verification purpose, and the analysis and simulation results demonstrate the effectiveness of the proposed modeling approach.
Document ID
20170009839
Acquisition Source
Ames Research Center
Document Type
Accepted Manuscript (Version with final changes)
Authors
Ali Khudhair Al-Jiboory (Michigan State University East Lansing, Michigan, United States)
Guoming Zhu (Michigan State University East Lansing, Michigan, United States)
Sean Shan-min Swei (Ames Research Center Mountain View, California, United States)
Weihua Su (University of Alabama, Tuscaloosa Tuscaloosa, Alabama, United States)
Nhan T Nguyen, (Ames Research Center Mountain View, California, United States)
Date Acquired
October 11, 2017
Publication Date
March 10, 2017
Publication Information
Publication: Aerospace Science and Technology
Publisher: Elsevier
Volume: 66
Issue Publication Date: July 1, 2017
ISSN: 1270-9638
DOI: doi:10.1016/j.ast.2017.03.009
Subject Category
Numerical Analysis
Structural Mechanics
Report/Patent Number
ARC-E-DAA-TN39386
Funding Number(s)
CONTRACT_GRANT: NNX15AG65G
CONTRACT_GRANT: NNX15AR80G
Distribution Limits
Public
Copyright
Public Use Permitted.
Keywords
LPV Modeling
H-2 norm
H-infinity norm.

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