› › Nonlinear Stability And Control Study Of Highly Maneuverable High Performance Aircraft

Nonlinear Stability and Control Study of Highly Maneuverable High Performance Aircraft

Author : National Aeronautics and Space Adm Nasa

Publisher : Independently Published

Page : 124 pages

File Size : 36,77 MB

Release : 2018-11-14

Category : Science

ISBN : 9781731303264

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Book Description

This project is intended to research and develop new nonlinear methodologies for the control and stability analysis of high-performance, high angle-of-attack aircraft such as HARV (F18). Past research (reported in our Phase 1, 2, and 3 progress reports) is summarized and more details of final Phase 3 research is provided. While research emphasis is on nonlinear control, other tasks such as associated model development, system identification, stability analysis, and simulation are performed in some detail as well. An overview of various models that were investigated for different purposes such as an approximate model reference for control adaptation, as well as another model for accurate rigid-body longitudinal motion is provided. Only a very cursory analysis was made relative to type 8 (flexible body dynamics). Standard nonlinear longitudinal airframe dynamics (type 7) with the available modified F18 stability derivatives, thrust vectoring, actuator dynamics, and control constraints are utilized for simulated flight evaluation of derived controller performance in all cases studied. Mohler, R. R. Unspecified Center ADAPTIVE CONTROL; AIRCRAFT PERFORMANCE; AIRCRAFT STABILITY; FLIGHT SIMULATION; HIGHLY MANEUVERABLE AIRCRAFT; NEURAL NETS; OPTIMAL CONTROL; ANGLE OF ATTACK; CONTROLLERS; F-18 AIRCRAFT; NONLINEAR FEEDBACK...



Nonlinear Stability and Control Study of Highly Maneuverable High Performance Aircraft, Phase 2

Author : National Aeronautics and Space Administration (NASA)

Publisher : Createspace Independent Publishing Platform

Page : 70 pages

File Size : 32,36 MB

Release : 2018-07-10

Category :

ISBN : 9781722671129

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Book Description

This research should lead to the development of new nonlinear methodologies for the adaptive control and stability analysis of high angle-of-attack aircraft such as the F18 (HARV). The emphasis has been on nonlinear adaptive control, but associated model development, system identification, stability analysis and simulation is performed in some detail as well. Various models under investigation for different purposes are summarized in tabular form. Models and simulation for the longitudinal dynamics have been developed for all types except the nonlinear ordinary differential equation model. Briefly, studies completed indicate that nonlinear adaptive control can outperform linear adaptive control for rapid maneuvers with large changes in alpha. The transient responses are compared where the desired alpha varies from 5 degrees to 60 degrees to 30 degrees and back to 5 degrees in all about 16 sec. Here, the horizontal stabilator is the only control used with an assumed first-order linear actuator with a 1/30 sec time constant. Mohler, R. R. Unspecified Center...



Nonlinear Control of High Performance Aircraft

Author : Ronnie A. Bean

Publisher :

Page : 158 pages

File Size : 18,7 MB

Release : 1994

Category : Jet planes, Military

ISBN :

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Book Description

This thesis presents the design of various controllers for a highly maneuverable, high performance aircraft, namely the modified F-18. The aircraft was required to perform high angle-of-attack maneuvers, for which the aircraft behaves in as a highly nonlinear system. An adaptive PID controller was used to control the aircraft through these high angle-of-attack maneuvers. Several nonlinear controllers were then developed based on the adaptive PID control, and were tested for robustness. This thesis also looks at an improvement in the aircraft which may improve performance in high angle-of-attack maneuvers. The contributions of this thesis are in the areas of control, in general, and specifically in the area of aircraft control. Successful application of linear adaptive control and nonlinear control were presented. In the area of aircraft control, controllers were presented which produce good performance for high angle-of-attack maneuvers, while maintaining implementability. Also, some insight is gained into what aircraft changes could improve performance.



Nonlinear Adaptive Control of Highly Maneuverable High Performance Aircraft

Author : Sul Cho

Publisher :

Page : 214 pages

File Size : 29,60 MB

Release : 1993

Category : Airplanes

ISBN :

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Book Description

This thesis presents an effective control design methodology using a one-step-ahead prediction adaptive control law and an adaptive control law based on a Lyapunov function. These control law were applied to a highly maneuverable high performance aircraft, in particular, a modified F/A-18. An adaptive controller is developed to maneuver an aircraft at a high angle of attack even if the aircraft is required to fly over a highly nonlinear flight regime. The adaptive controller presented in this thesis is based on linear, bilinear, and nonlinear prediction models with input constraints. It is shown that the linear, bilinear, and nonlinear adaptive controllers can be constructed to minimize the given cost function or Lyapunov function with respect to the control input at each step. The control is calculated such that the system follows the reference trajectory, and such that control signal remains within its constraints. From several simulation results, the nonlinear controller is controller is better than the linear controller. A nonlinear adaptive control law based on a Lyapunov function is designed such that control inputs are smoother than for the one-step-ahead prediction adaptive controller.