Download or read book An Evaluation of Frequency Domain Ensemble Averging to Improve Aircraft Stability Derivative Estimation written by Lawrence Hoffman and published by . This book was released on 1998-03-01 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research evaluated a process to improve aircraft stability derivative estimation results. The Have Derivatives process used overlap ensemble averaging in the frequency domain to minimize noise on the original time domain signals. The process estimated average complex frequency response functions that were then transformed back into the time domain as a set of discrete pulse responses with far less noise than the original signals. These clean signals were used in a parameter estimation program to estimate better stability derivatives than were estimated with the original noisy signals. Both simulation and flight test data were used to study the effects of various noise levels on stability derivative estimation results and to evaluate the Have Derivatives process to improve those results. The simulations demonstrated dramatic improvement using the Have Derivatives process. The flight test results were not as conclusive. The ensemble averaging step of the Have Derivatives process was not effective enough at reducing noise on the flight test data due to non-uniform frequency content of the flight test input. The overall recommendation was to further evaluate the Have Derivatives process using a broadband flight test input, similar to the input that worked well in simulation.

Download or read book An Evaluation of Frequency Domain Ensemble Averaging to Improve Aircraft Stability Derivative Estimation written by Lawrence M. Hoffman and published by . This book was released on 1998 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Real Time Stability and Control Derivative Extraction from F 15 Flight Data written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-16 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: A real-time, frequency-domain, equation-error parameter identification (PID) technique was used to estimate stability and control derivatives from flight data. This technique is being studied to support adaptive control system concepts currently being developed by NASA (National Aeronautics and Space Administration), academia, and industry. This report describes the basic real-time algorithm used for this study and implementation issues for onboard usage as part of an indirect-adaptive control system. A confidence measures system for automated evaluation of PID results is discussed. Results calculated using flight data from a modified F-15 aircraft are presented. Test maneuvers included pilot input doublets and automated inputs at several flight conditions. Estimated derivatives are compared to aerodynamic model predictions. Data indicate that the real-time PID used for this study performs well enough to be used for onboard parameter estimation. For suitable test inputs, the parameter estimates converged rapidly to sufficient levels of accuracy. The devised confidence measures used were moderately successful.Smith, Mark S. and Moes, Timothy R. and Morelli, Eugene A.Armstrong Flight Research Center; Langley Research CenterF-15 AIRCRAFT; PARAMETER IDENTIFICATION; REAL TIME OPERATION; STABILITY DERIVATIVES; CONTROL STABILITY; CONTROL SYSTEMS DESIGN; FREQUENCY DOMAIN ANALYSIS; FLIGHT CONDITIONS; INDUSTRIES; NASA PROGRAMS; FOURIER TRANSFORMATION; REGRESSION ANALYSIS; ALGORITHMS; ERROR ANALYSIS; ONBOARD DATA PROCESSING

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1989 with total page 984 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Frequency Domain Estimation of the Short Period Longitudinal Stability and Control Derivatives of an Experimental Business Jet written by Travis Jay Bailey and published by . This book was released on 1998 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Application of Frequency Domain Optimization to Improve the Lateral Stability of the F 4 Aircraft written by Patrick D. O'Brien (1LT, USAF.) and published by . This book was released on 1969 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aircraft System Identification written by Eugene Morelli and published by Sunflyte Enterprises. This book was released on 2016 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive overview of both the theoretical underpinnings and the practical application of aircraft modeling based on experimental data also known as aircraft system identification. Much of the material presented comes from the authors own extensive research and teaching activities at the NASA Langley Research Center, and is based on real-world applications of system identification to aircraft. The book uses actual flight-test and wind-tunnel data for case studies and examples, and is a valuable resource for researchers and practicing engineers, as well as a textbook for postgraduate and senior-level courses. [...] The methods and algorithms explained in the book are implemented in a NASA software toolbox called SIDPAC (System IDentification Programs for AirCraft). SIDPAC is written in MATLAB®, and is available by request from NASA Langley Research Center. SIDPAC is composed of many different tools that implement a wide variety of approaches explained fully in the book. These tools can be readily applied to solve aircraft system identification problems.

Download or read book Photoplethysmography written by Panicos A. Kyriacou and published by Academic Press. This book was released on 2021-11-03 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photoplethysmography: Technology, Signal Analysis, and Applications is the first comprehensive volume on the theory, principles, and technology (sensors and electronics) of photoplethysmography (PPG). It provides a detailed description of the current state-of-the-art technologies/optical components enabling the extreme miniaturization of such sensors, as well as comprehensive coverage of PPG signal analysis techniques including machine learning and artificial intelligence. The book also outlines the huge range of PPG applications in healthcare, with a strong focus on the contribution of PPG in wearable sensors and PPG for cardiovascular assessment. Presents the underlying principles and technology surrounding PPG Includes applications for healthcare and wellbeing Focuses on PPG in wearable sensors and devices Presents advanced signal analysis techniques Includes cutting-edge research, applications and future directions

Download or read book Aeroacoustics of Flight Vehicles written by Harvey H. Hubbard and published by . This book was released on 1991 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2003 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Window Functions and Their Applications in Signal Processing written by K. M. M. Prabhu and published by CRC Press. This book was released on 2018-09-03 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Window functions—otherwise known as weighting functions, tapering functions, or apodization functions—are mathematical functions that are zero-valued outside the chosen interval. They are well established as a vital part of digital signal processing. Window Functions and their Applications in Signal Processing presents an exhaustive and detailed account of window functions and their applications in signal processing, focusing on the areas of digital spectral analysis, design of FIR filters, pulse compression radar, and speech signal processing. Comprehensively reviewing previous research and recent developments, this book: Provides suggestions on how to choose a window function for particular applications Discusses Fourier analysis techniques and pitfalls in the computation of the DFT Introduces window functions in the continuous-time and discrete-time domains Considers two implementation strategies of window functions in the time- and frequency domain Explores well-known applications of window functions in the fields of radar, sonar, biomedical signal analysis, audio processing, and synthetic aperture radar

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1995 with total page 944 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Signal Analysis written by Ronald L. Allen and published by John Wiley & Sons. This book was released on 2004-06-07 with total page 961 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offers a well-rounded, mathematical approach to problems in signal interpretation using the latest time, frequency, and mixed-domain methods Equally useful as a reference, an up-to-date review, a learning tool, and a resource for signal analysis techniques Provides a gradual introduction to the mathematics so that the less mathematically adept reader will not be overwhelmed with instant hard analysis Covers Hilbert spaces, complex analysis, distributions, random signals, analog Fourier transforms, and more

Download or read book Harmonic Balance for Nonlinear Vibration Problems written by Malte Krack and published by Springer. This book was released on 2019-03-23 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph presents an introduction to Harmonic Balance for nonlinear vibration problems, covering the theoretical basis, its application to mechanical systems, and its computational implementation. Harmonic Balance is an approximation method for the computation of periodic solutions of nonlinear ordinary and differential-algebraic equations. It outperforms numerical forward integration in terms of computational efficiency often by several orders of magnitude. The method is widely used in the analysis of nonlinear systems, including structures, fluids and electric circuits. The book includes solved exercises which illustrate the advantages of Harmonic Balance over alternative methods as well as its limitations. The target audience primarily comprises graduate and post-graduate students, but the book may also be beneficial for research experts and practitioners in industry.

Download or read book Rotorcraft System Identification written by and published by . This book was released on 1991 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1995 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: