[PDF] Air Breathing Hypersonic Vehicle Guidance And Control Studies eBook

Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
Page : 88 pages
File Size : 28,58 MB
Release : 2018-07-02
Category :
ISBN : 9781722169855

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An integrated trajectory/control analysis algorithm has been used to generate trajectories and desired control strategies for two different hypersonic air-breathing vehicle models and orbit targets. Both models used cubic spline curve fit tabulated winged-cone accelerator vehicle representations. Near-fuel-optimal, horizontal takeoff trajectories, imposing a dynamic pressure limit of 1000 psf, were developed. The first model analysis case involved a polar orbit and included the dynamic effects of using elevons to maintain longitudinal trim. Analysis results indicated problems with the adequacy of the propulsion model and highlighted dynamic pressure/altitude instabilities when using vehicle angle of attack as a control variable. Also, the magnitude of computed elevon deflections to maintain trim suggested a need for alternative pitch moment management strategies. The second analysis case was reformulated to use vehicle pitch attitude relative to the local vertical as the control variable. A new, more realistic, air-breathing propulsion model was incorporated. Pitch trim calculations were dropped and an equatorial orbit was specified. Changes in flight characteristics due to the new propulsion model have been identified. Flight regimes demanding rapid attitude changes have been noted. Also, some issues that would affect design of closed-loop controllers were ascertained. Hattis, Philip D. and Malchow, Harvey L. Unspecified Center...

Author : National Research Council
Publisher : National Academies Press
Page : 76 pages
File Size : 48,75 MB
Release : 1998-09-05
Category : Technology & Engineering
ISBN : 0309061423

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This study was undertaken in response to a request by the U.S. Air Force that the National Research Council (NRC) examine whether the technologies that underlie the concept of a hypersonic, air-launched, air-breathing, hydrocarbon-fueled missile with speeds up to Mach 81 can be demonstrated in time to be initially operational by 2015. To conduct the study, the NRC appointed the Committee on Review and Evaluation of the Air Force Hypersonic Technology Program, under the auspices of the Air Force Science and Technology Board.

Author : Ruizhuo Song
Publisher : Springer
Page : 271 pages
File Size : 42,90 MB
Release : 2018-12-28
Category : Technology & Engineering
ISBN : 9811317127

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This book presents a class of novel optimal control methods and games schemes based on adaptive dynamic programming techniques. For systems with one control input, the ADP-based optimal control is designed for different objectives, while for systems with multi-players, the optimal control inputs are proposed based on games. In order to verify the effectiveness of the proposed methods, the book analyzes the properties of the adaptive dynamic programming methods, including convergence of the iterative value functions and the stability of the system under the iterative control laws. Further, to substantiate the mathematical analysis, it presents various application examples, which provide reference to real-world practices.

Author : Wanchun Chen
Publisher : Springer Nature
Page : 461 pages
File Size : 14,22 MB
Release : 2020-11-07
Category : Technology & Engineering
ISBN : 9811589011

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This book presents the latest researches on hypersonic steady glide dynamics and guidance, including the concept of steady glide reentry trajectory and the stability of its regular perturbation solutions, trajectory damping control technique for hypersonic glide reentry, singular perturbation guidance of hypersonic glide reentry, trajectory optimization based on steady glide, linear pseudospectral generalized nominal effort miss distance guidance, analytical entry guidance and trajectory-shaping guidance with final speed and load factor constraints. They can be used to solve many new difficult problems in entry guidance. And many practical engineering cases are provided for the readers for better understanding. Researchers and students in the fields of flight vehicle design or flight dynamics, guidance and control could use the book as valuable reference.

Author : Kevin P. Groves
Publisher :
Page : 0 pages
File Size : 31,53 MB
Release : 2005
Category : Hypersonic planes
ISBN :

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Seen as a possible way of making space access more affordable, air-breathing hypersonic vehicles have been studied sporadically over the last five decades as the technical advances necessary for their development were missing. New technology has brought a renewed interest in the research area, as demonstrated by the successful flights of NASA's X-43A in April and November of 2004. Air-breathing hypersonic vehicles are characterized by their unique design, incorporating a supersonic combustion ramjet engine located beneath the fuselage. This esoteric configuration results in strong coupling between the thrust and pitch dynamics of the vehicle, which in combination with flexible effects and static instability make the vehicle a challenging application for control. For a particular model of the longitudinal dynamics of an air-breathing hypersonic vehicle, a nonlinear high fidelity simulation is developed. Tables are generated which provide a static mapping of the states/inputs to the aero-dynamic forces for the purpose of creating bounds to be used in future nonlinear control development. The tables also allow the calculation of the aerodynamics forces and moments to be replaced by a table look-up with multidimensional interpolation. A linear controller is designed using a linearized model derived numerically from the nonlinear simulation about a specific trim condition. The controller is designed to track given reference commands in velocity, angle-of-attack, and altitude using a LQR technique. The gains are tuned to achieve the performance objectives without violating the input constraints. The controller is then tested on the nonlinear simulation and functions adeptly. Anti-windup control is added to allow the input constraints to be considered in the formulation of the linear controller. In doing so the gains of the linear controller can be increased without manually keeping the inputs within their constraints through tuning of the weighting matrices. This allows both the speed of the closed loop response and that of the reference trajectories to be increased, resulting in better performance.

Author : Benjamin R. Szpak
Publisher :
Page : 33 pages
File Size : 36,1 MB
Release : 2009
Category :
ISBN :

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Abstract: Air-breathing hypersonic vehicles have risen to the forefront of the aerospace research community in reaction to the requirements of NASA and the US Air Force. NASA has interest in developing a next generation Reusable Launch Vehicle and the US Air Force is interested in an unmanned hypersonic vehicle. Recent research has focused on developing comprehensive models in order to successfully design a vehicle capable of operating in the severe hypersonic environment. Due to the layout of this class of vehicle, where the propulsion system is fully integrated into the lifting body fuselage, a tight coupling exists between the airframe, propulsion system, control system, and aerodynamics. This characteristic necessitates a multi-disciplinary approach to modeling for control design. To achieve this, a simplified model of each subsystem is needed to efficiently perform a multi-disciplinary analysis. Two important and challenging areas for multi-disciplinary modeling are the incorporation of complex aerodynamic and aerothermoelastic phenomena. The focus of this research is on the development of a model for the control surface. Specifically an aerothermoelastic model, based on a plate representation, has been developed for the vehicle control surface. This model was adapted from a previous model, developed at the Air Force Research Laboratory, to incorporate important characteristics such as taper and sweep of the control surface. Thus, the model more realistically represents the geometry of a control surface for a hypersonic vehicle. The structural model developed was then verified using finite element analysis to compare the free vibration frequencies and modeshapes. Since the structural dynamic characteristics of a solid plate are not compatible to those of a shell structured wing, the structural properties were modified to match the first two frequencies of a representative wing, namely the F-104 Lockheed Starfighter wing. As the temperature of a plate increases, the first two frequencies begin to coalesce. This coalescence of frequencies leads to a phenomena known as flutter. As the temperature of the plate was increased the aerothermoelastic response was computed at a constant Mach number until the onset of flutter. By implementing a flexible control surface model, the response of the wing to control inputs and fuselage deformations could also be investigated. Both of these effects are modeled as base motion of the cantilevered plate. Second order piston theory, a commonly used model for hypersonic aerodynamics, was used to calculate the aerodynamic forces on the plate. Results presented provide insight into the importance of aerothermoelastic effects for control oriented modeling, as well as the effect of plate sweep and taper compared to a simple square plate representation.