Download or read book Aeroservoelastic Modeling Analysis and Design Techniques for Transport Aircraft written by Myles L. Baker and published by . This book was released on 2000 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Piloted and batch simulations of the aeroservoelastic response of flight vehicles are essential tools in the development of advanced flight control systems. In these simulations the number of differential equations must be sufficiently large to yield the required accuracy, yet small enough to enable real- time evaluations of the aircraft flying qualities and rapid batch simulations for control law design. The challenge of these conflicting demands is made especially difficult by the limited accuracy of the analytical modeling techniques used, nonlinearities in the quasi-steady equations of motion and by the complex characteristics of the unsteady aerodynamic forces. In this paper, a brief survey of some of the techniques that have been used at Boeing to develop aeroservoelastic math models for control system design and evaluation are presented, along with a discussion of the strengths and weaknesses of the various techniques. The modeling techniques discussed include frequency response fitting methods, rational function approximation methods, and the P- Transform technique. Integration of the aeroservoelastic structural dynamic model with a nonlinear flight simulation is also discussed.
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 Flight Mechanics Modeling and Analysis written by Jitendra R. Raol and published by CRC Press. This book was released on 2008-08-20 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design, development, analysis, and evaluation of new aircraft technologies such as fly by wire, unmanned aerial vehicles, and micro air vehicles, necessitate a better understanding of flight mechanics on the part of the aircraft-systems analyst. A text that provides unified coverage of aircraft flight mechanics and systems concept will go a lon
Download or read book Modeling Flexible Aircraft for Flight Control Design written by E. C. Bekir and published by . This book was released on 1989 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Trends to lower structural fraction of aircraft increase flexibility effects. Higher bandwidth control systems combined with these more flexible structures cause more aeroservoelastic interactions. Active, closed-loop control systems allow greater flexibility. To take advantage of this design possibility, an integrated ASE model is needed for conceptual and preliminary design stages of aircraft. This report seeks to define the equations of motion of a flexible aircraft from first principles to aid future discussions between experts in the specialties which make up ASE: aerodynamics, controls, and structures. This theoretical report documents the development of the equations, and states under what conditions the assumptions and approximations are accurate. It consists of 5 sections on different technical areas and a summary section: 1) Linearization of flexible aircraft hybrid-coordinate dynamic equations and inclusion of aerodynamic and gravitational loads; 2) Derivation of equations of motion and stability derivatives for a flexible aircraft vehicle; 3) Aerodynamics for aeroservoelasticity; 4) Model-order reduction for linear systems; and 5) Hydraulic actuator equations for aeroservoelastic modeling. Flight control systems; Servomechanisms. (edc).
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 Aeroservoelastic Modeling and Validation of a Thrust Vectoring F a 18 Aircraft written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-02 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: An F/A-18 aircraft was modified to perform flight research at high angles of attack (AOA) using thrust vectoring and advanced control law concepts for agility and performance enhancement and to provide a testbed for the computational fluid dynamics community. Aeroservoelastic (ASE) characteristics had changed considerably from the baseline F/A-18 aircraft because of structural and flight control system amendments, so analyses and flight tests were performed to verify structural stability at high AOA. Detailed actuator models that consider the physical, electrical, and mechanical elements of actuation and its installation on the airframe were employed in the analysis to accurately model the coupled dynamics of the airframe, actuators, and control surfaces. This report describes the ASE modeling procedure, ground test validation, flight test clearance, and test data analysis for the reconfigured F/A-18 aircraft. Multivariable ASE stability margins are calculated from flight data and compared to analytical margins. Because this thrust-vectoring configuration uses exhaust vanes to vector the thrust, the modeling issues are nearly identical for modem multi-axis nozzle configurations. This report correlates analysis results with flight test data and makes observations concerning the application of the linear predictions to thrust-vectoring and high-AOA flight. Brenner, Martin J. Armstrong Flight Research Center...
Download or read book Aeroservoelastic Characteristics of the B 2 Bomber and Implications for Future Large Aircraft written by R. T. Britt and published by . This book was released on 2000 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Design and development of the B-2 Bomber presented many challenges in flexible vehicle control, many related to the unique configuration and design requirements. The technical challenges posed by the aeroelastic characteristics of the all-wing aircraft were recognized at the outset of the development program and included the configuration 5 near-neutral pitch stability and light wing loading which made the aircraft highly responsive to atmospheric turbulence. This dictated the requirement for an active digital flight control system to provide both stability augmentation and gust load alleviation. The gust load alleviation flight control system was designed by a multidisciplinary team using a combination of optimal and classical control design techniques and a common analysis model database. Accurate representation of the vehicle aerodynamics characteristics, actuators, and sensors were key to successfully developing and testing the flight control system and verifying performance requirements. Flight test data analysis included the extraction of the vehicle open loop response which were utilized to adjust the analytical models and make final revisions to control law gains. The multidisciplinary design approach resulted in the successful development of a control augmentation system that provides the B-2 with superb handling characteristics, acceptable low altitude ride quality, and substantial alleviation of gust loads on the airframe. With this back drop, a technology assessment is performed which discusses potential technology improvements for application to future bomber and large transport aircraft.
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 A Methodology for Using Nonlinear Aerodynamics in Aeroservoelastic Analysis and Design written by and published by . This book was released on 1991 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quasi analytical Modelling and Optimisation Techniques for Transport Aircraft Design written by Askin T. Isikveren and published by . This book was released on 2002 with total page 236 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 Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Methodology for Using Nonlinear Aerodynamics in Aeroservoelastic Analysis and Design written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-09 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: A methodology is presented for using the Volterra-Wiener theory of nonlinear systems in aeroservoelastic (ASE) analyses and design. The theory is applied to the development of nonlinear aerodynamic response models that can be defined in state-space form and are, therefore, appropriate for use in modern control theory. The theory relies on the identification of nonlinear kernels that can be used to predict the response of a nonlinear system due to an arbitrary input. A numerical kernel identification technique, based on unit impulse responses, is presented and applied to a simple bilinear, single-input single-output (SISO) system. The linear kernel (unit impulse response) and the nonlinear second-order kernel of the system are numerically-identified and compared with the exact, analytically-defined and linear and second-order kernels. This kernel identification technique is then applied to the CAP-TSD (Computational Aeroelasticity Program-Transonic Small Disturbance) code for identification of the linear and second-order kernels of a NACA64A010 rectangular wing undergoing pitch at M = 0.5, M = 8.5 (transonic), and M = 0.93 (transonic). Results presented demonstrate the feasibility of this approach for use with nonlinear, unsteady aerodynamic responses. Silva, Walter A. Langley Research Center NASA-TM-104087, NAS 1.15:104087 RTOP 509-10-02-03...
Download or read book Aeroservoelastic Modeling and Validation of a Thrust Vectoring F A 18 Aircraft written by Martin J. Brenner and published by . This book was released on 1996 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling of Transportation Aviation Processes written by Georgy Alekseevich Kryzhanovsky and published by Springer Nature. This book was released on 2023-03-14 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the fundamental methods of modeling, analysis and synthesis of transport processes which allow: - to optimize the work of transport organizations according to different criteria of their functioning; - to evaluate the quality of decisions made in conditions of high entropy and uncertainty of technological processes when applying new technologies and systems; -to reduce the negative impact of the human factor on the safety of ongoing transport processes by increasing the motivational component of the training processes for the operator of active transport systems. The structural diagrams presented in this book make it possible to visualize the processes of training, self-training of operators and the mechanisms of the formation of volitional motivational efforts under various external influences of the environment and the teacher–instructor. The obtained functional dependencies serve as an assessment for determining and forming the dynamics of motivation and making a decision about the readiness for safe work of the operator of active transport systems and the decision-maker in the new conditions of the technological process.
Download or read book Application of Three Aeroservoelastic Stability Analysis Techniques written by R. P Peloubet (Jr) and published by . This book was released on 1976 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes two types of instabilities encountered by the YF-16 airplane that were caused by a coupling between the active control system and structural dynamics. Three mathematical models of the airplane were evaluated to determine the degree of correlation between analysis and flight tests. These mathematical models are described as: (1) Truncated Mode Analysis Using GVT Modes; (2) Truncated Mode Analysis Using Computed Modes; and (3) Residual Flexibility Method Using Computed Modes. Stability was determined in the frequency domain by employing the Nyquist criteria and the determinant plot. A method is presented for computing indicial functions from oscillatory generalized aerodynamic terms obtained from any linearlized aerodynamic theory. The equations for employing the indicial functions in a root locus stability analysis are presented. Stability was determined by the root locus method for the mathematical model described as the truncated mode analysis using computed modes. The degree of correlation between analysis and flight test is shown. Recommendations for analysis techniques, tests, and criteria are made.
Download or read book NASA SP written by and published by . This book was released on 1992 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt:
