Download or read book Aeroservoelastic Uncertainty Model Identification from Flight Data written by Martin J. Brenner and published by . This book was released on 2001 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeroservoelastic Uncertainty Model Identification from Flight Data Nasa written by United States. National Aeronautics and Space Administration and published by . This book was released on 2003* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeroservoelastic Model Validation and Test Data Analysis of the F a 18 Active Aeroelastic Wing written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-20 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Model validation and flight test data analysis require careful consideration of the effects of uncertainty, noise, and nonlinearity. Uncertainty prevails in the data analysis techniques and results in a composite model uncertainty from unmodeled dynamics, assumptions and mechanics of the estimation procedures, noise, and nonlinearity. A fundamental requirement for reliable and robust model development is an attempt to account for each of these sources of error, in particular, for model validation, robust stability prediction, and flight control system development. This paper is concerned with data processing procedures for uncertainty reduction in model validation for stability estimation and nonlinear identification. F/A-18 Active Aeroelastic Wing (AAW) aircraft data is used to demonstrate signal representation effects on uncertain model development, stability estimation, and nonlinear identification. Data is decomposed using adaptive orthonormal best-basis and wavelet-basis signal decompositions for signal denoising into linear and nonlinear identification algorithms. Nonlinear identification from a wavelet-based Volterra kernel procedure is used to extract nonlinear dynamics from aeroelastic responses, and to assist model development and uncertainty reduction for model validation and stability prediction by removing a class of nonlinearity from the uncertainty. Brenner, Martin J. and Prazenica, Richard J. Armstrong Flight Research Center NASA/TM-2003-212021, H-2526, NAS 1.15:212021
Download or read book Robust Aeroservoelastic Stability Analysis written by Rick Lind and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Advances in Industrial Control aims to report and encourage technology transfer in control engineering. The rapid development of control technology impacts all areas of the control discipline. New theory, new controllers, actuators, sensors, new industrial processes, computer methods, new applications, new philosophies, . . . . , new challenges. Much of this deVelopment work resides in industrial reports, feasibility study papers and the reports of advanced collaborative projects. The series offers an opportunity for researchers to present an extended exposition of such new work in all aspects of industrial control for wider and rapid dissemination. The high performance control systems applications in aerospace and astronautics almost have a tradition of exploiting the most advanced control theoretical developments first. The optimal control and ffitering paradigm associated with the names of Kalman, Bucy, Anderson and Moore found application in the astronautics of the 1960'S and 1970'S. At the beginning of the 1980'S, control theory moved on to robustness, singular values and mu-analysis. This new work was associated with the names of Zames, Doyle, Glover, Balas among others. The Advances in Industrial Control monograph series have published several volumes over the years which have archived the applications experience garnered from applying robust control to the aerospace sector problems. Rick Lind and Marty Brenner add to this set with their volume on robust aeroservoelastic stability. This volume reports the application of the structured singular value to aeroelastic and aeroservoelastic aerospace problems.
Download or read book Wavelet Filtering to Reduce Conservatism in Aeroservoelastic Robust Stability Margins written by Marty Brenner and published by . This book was released on 1998 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Closed loop Model Validation with Application to an Aeroservoelastic System written by Marianne Crowder and published by . This book was released on 2004 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeroservoelasticity written by Ashish Tewari and published by Springer. This book was released on 2015-03-24 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph presents the state of the art in aeroservoelastic (ASE) modeling and analysis and develops a systematic theoretical and computational framework for use by researchers and practicing engineers. It is the first book to focus on the mathematical modeling of structural dynamics, unsteady aerodynamics, and control systems to evolve a generic procedure to be applied for ASE synthesis. Existing robust, nonlinear, and adaptive control methodology is applied and extended to some interesting ASE problems, such as transonic flutter and buffet, post-stall buffet and maneuvers, and flapping flexible wing. The author derives a general aeroservoelastic plant via the finite-element structural dynamic model, unsteady aerodynamic models for various regimes in the frequency domain, and the associated state-space model by rational function approximations. For more advanced models, the full-potential, Euler, and Navier-Stokes methods for treating transonic and separated flows are also briefly addressed. Essential ASE controller design and analysis techniques are introduced to the reader, and an introduction to robust control-law design methods of LQG/LTR and H2/H∞ synthesis is followed by a brief coverage of nonlinear control techniques of describing functions and Lyapunov functions. Practical and realistic aeroservoelastic application examples derived from actual experiments are included throughout. Aeroservoelasiticity fills an important gap in the aerospace engineering literature and will be a valuable guide for graduate students and advanced researchers in aerospace engineering, as well as professional engineers, technicians, and test pilots in the aircraft industry and laboratories.
Download or read book Using System Identification to Compare Global and Local Aerodynamic Modeling from Flight Data written by Toby Earl Sorensen and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method for identifying and comparing a longitudinal global aerodynamic model to a longitudinal local aerodynamic model for UTSI’s Piper Saratoga aircraft is explained and demonstrated. Large amplitude piloted inputs were used to estimate global nonlinear aerodynamic models from flight data. Flight derived global aerodynamic model structures, model parameter estimates, and associated uncertainties were provided for the longitudinal dimensional force and moment. The results from the global aerodynamic modeling were compared to local linear aerodynamic modeling results gathered with traditional small amplitude doublet inputs. The results from large amplitude piloted inputs compared favorably with small amplitude piloted inputs by ten percent in almost all cases and in significantly less test time.
Download or read book Overview of Recent Flight Flutter Testing Research at NASA Dryden written by Martin J. Brenner and published by . This book was released on 1997 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wavelet Analyses of F A 18 Aeroelastic and Aeroservoelastic Flight Test Data written by Martin J. Brenner and published by . This book was released on 1997 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Time-frequency signal representations combined with subspace identification methods were used to analyze aeroelastic flight data from the F/A-18 Systems Research Aircraft (SRA) and aeroservoelastic data from the F/A-18 High Alpha Research Vehicle (HARV). The F/A-18 SRA data were produced from a wingtip excitation system that generated linear frequency chirps and logarithmic sweeps. HARV data were acquired from digital Schroeder-phased and sinc pulse excitation signals to actuator commands. Nondilated continuous Morlet wavelets implemented as a filter bank were chosen for the time-frequency analysis to eliminate phase distortion as it occurs with sliding window discrete Fourier transform techniques. Wavelet coefficients were filtered to reduce effects of noise and nonlinear distortions identically in all inputs and outputs. Cleaned reconstructed time domain signals were used to compute improved transfer functions. Time and frequency domain subspace identification methods were applied to enhanced reconstructed time domain data and improved transfer functions, respectively. Time domain subspace performed poorly, even with the enhanced data, compared with frequency domain techniques. A frequency domain subspace method is shown to produce better results with the data processed using the Morlet time-frequency technique.
Download or read book AIAA Journal written by American Institute of Aeronautics and Astronautics and published by . This book was released on 2008 with total page 1112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On Line Robust Modal Stability Prediction Using Wavelet Processing written by Martin J. Brenner and published by . This book was released on 1998 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Tech Briefs written by and published by . This book was released on 1998 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Aeronautical Journal written by and published by . This book was released on 2003 with total page 820 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Aeroservoelastic Control written by Ashish Tewari and published by John Wiley & Sons. This book was released on 2016-02-08 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first book on adaptive aeroservoelasticity and it presents the nonlinear and recursive techniques for adaptively controlling the uncertain aeroelastic dynamics Covers both linear and nonlinear control methods in a comprehensive manner Mathematical presentation of adaptive control concepts is rigorous Several novel applications of adaptive control presented here are not to be found in other literature on the topic Many realistic design examples are covered, ranging from adaptive flutter suppression of wings to the adaptive control of transonic limit-cycle oscillations
Download or read book Introduction to Structural Dynamics and Aeroelasticity written by Dewey H. Hodges and published by Cambridge University Press. This book was released on 2014-01-02 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text provides an introduction to structural dynamics and aeroelasticity, with an emphasis on conventional aircraft. The primary areas considered are structural dynamics, static aeroelasticity, and dynamic aeroelasticity. The structural dynamics material emphasizes vibration, the modal representation, and dynamic response. Aeroelastic phenomena discussed include divergence, aileron reversal, airload redistribution, unsteady aerodynamics, flutter, and elastic tailoring. More than one hundred illustrations and tables help clarify the text, and more than fifty problems enhance student learning. This text meets the need for an up-to-date treatment of structural dynamics and aeroelasticity for advanced undergraduate or beginning graduate aerospace engineering students. Praise from the First Edition "Wonderfully written and full of vital information by two unequalled experts on the subject, this text meets the need for an up-to-date treatment of structural dynamics and aeroelasticity for advanced undergraduate or beginning graduate aerospace engineering students." - Current Engineering Practice "Hodges and Pierce have written this significant publication to fill an important gap in aeronautical engineering education. Highly recommended." - Choice ". . . a welcome addition to the textbooks available to those with interest in aeroelasticity. . . . As a textbook, it serves as an excellent resource for advanced undergraduate and entry-level graduate courses in aeroelasticity. . . . Furthermore, practicing engineers interested in a background in aeroelasticity will find the text to be a friendly primer." - AIAA Bulletin
Download or read book Contributions to Physics based Aeroservoelastic Uncertainty Analysis written by Sang Wu and published by . This book was released on 2016 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thesis presents the development of a new fully-integrated, MATLAB based simulation capability for aeroservoelastic (ASE) uncertainty analysis that accounts for uncertainties in all disciplines as well as discipline interactions. This new capability allows probabilistic studies of complex configuration at a scope and with depth not known before. Several statistical tools and methods have been integrated into the capability to guide the tasks such as parameter prioritization, uncertainty reduction, and risk mitigation. The first task of the thesis focuses on aeroservoelastic uncertainty assessment considering control component uncertainty. The simulation has shown that attention has to be paid, if notch filters are used in the aeroservoelastic loop, to the variability and uncertainties of the aircraft involved. The second task introduces two innovative methodologies to characterize the unsteady aerodynamic uncertainty. One is a physically based aerodynamic influence coefficients element by element correction uncertainty scheme and the other is an alternative approach focusing on rational function approximation matrix uncertainties to evaluate the relative impact of uncertainty in aerodynamic stiffness, damping, inertia, or lag terms. Finally, the capability has been applied to obtain the gust load response statistics accounting for uncertainties in both aircraft and gust profiles. The gust response analysis shows a significant increase of the critical loads when system’s uncertainties are included. The work is expected to make a contribution to the understanding of the propagation of uncertainty and the resulting reliability of realistic integrated aeroservoelastic system inherent in real modern aircraft. This work will motivate more research in the aeroservoelastic uncertainty area regarding both methods development in general and reliability studies of different configurations of interest. The mathematical derivations which serve as the foundation of the capability are also well documented.
