A continuation design framework for nonlinear flight control problems

2006 ◽  
Vol 110 (1104) ◽  
pp. 85-96 ◽  
Author(s):  
T. S. Richardson ◽  
M. H. Lowenberg
Keyword(s):  
Flight Control ◽  
Systematic Approach ◽  
Control Law ◽  
Control Problems ◽  
Eigenstructure Assignment ◽  
Design Framework ◽  
Aircraft Control ◽  
Fighter Aircraft ◽  
Highly Nonlinear ◽  
Fifth Order

Abstract A methodology referred to as the continuation design framework is developed for application to nonlinear flight control problems. This forms the basis of a systematic approach to control system design for aircraft operating in highly nonlinear regions of the flight envelope. The essence of the continuation design framework is to combine bifurcation analysis with modern control methods such as eigenstructure assignment. Theoretical and practical issues of the approach are discussed with particular reference to the problems posed by agile fighter aircraft. The proposed methodology is applied to a fifth order hypothetical aircraft model and is shown to provide a visible, flexible and logical approach to nonlinear aircraft control law design.

scholarly journals Three-axis coupled flight control law design for flying wing aircraft using eigenstructure assignment method

2020 ◽  
Vol 33 (10) ◽  
pp. 2510-2526
Author(s):  
Lixin WANG ◽  
Ning ZHANG ◽  
Ting YUE ◽  
Hailiang LIU ◽  
Jianghui ZHU ◽  
...  
Keyword(s):  
Flight Control ◽  
Control Law ◽  
Eigenstructure Assignment ◽  
Assignment Method

A non-iterative design for aileron to rudder interconnect gain

2020 ◽  
pp. 1-12
Author(s):  
J. Myala ◽  
V.V. Patel ◽  
G.K. Singh
Keyword(s):  
Flight Control ◽  
Design Procedure ◽  
Surface Damage ◽  
Mode Frequency ◽  
Control Law ◽  
Lateral Control ◽  
Damage Scenario ◽  
Fighter Aircraft ◽  
Iterative Design ◽  
Control Authority

Abstract Aileron to Rudder Interconnect (ARI) gain is implemented on most fighter aircraft, primarily to reduce the side slip produced due to adverse yaw from pilot lateral control stick input and to improve the turn rate response. A systematic and non-iterative design procedure for ARI gain is proposed herein based on the evaluation of a transfer function magnitude at the aircraft roll mode frequency. The simplicity of the proposed method makes it useful for real-time flight control law reconfiguration in situations where the aileron control authority is diminished due to damage. This is demonstrated by a simulation example considering an aileron surface damage scenario.

Development of a control law to improve the handling qualities for short-range air-to-air combat maneuvers

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402093679
Author(s):  
Chong-Sup Kim ◽  
Chang-Ho Ji ◽  
Byoung Soo Kim
Keyword(s):  
Flight Control ◽  
Short Range ◽  
Control Method ◽  
Control Law ◽  
Fighter Aircraft ◽  
Handling Qualities ◽  
Flying Qualities ◽  
Air Combat ◽  
Handling Quality ◽  
The Mathematical Model

Modern fighter aircraft have been designed to have high maneuverability in order to preoccupy strategic superiority in short-range air-to-air combat between fighter aircraft in warfare. Digital fly-by-wire flight control system design is aimed at providing good handling qualities for all mission task elements over the entire flight envelope. To provide both excellent gross acquisition and fine tracking compatibility, simultaneously for air-to-air combat maneuvers, this article presents a common longitudinal control law design of a task-dependent self-adjusting command-path pilot prefilter gain scheduler within the same control law design architecture and response type based on nonlinear dynamic inversion control. We perform the frequency- and time-domain analyses based on the mathematical model of T-50 advanced trainer aircraft to evaluate the basic flying qualities of the proposed control method. Furthermore, the pilot evaluation is performed to evaluate the gross acquisition and fine tracking capability for air-to-air tracking maneuvers in a handling quality simulator. The evaluation results reveal that the proposed control method improves the fine tracking capability without the degradation of gross acquisition.

scholarly journals Applying Eigenstructure Assignment to Inner-Loop Flight Control Laws for a Multibody Aircraft

2021 ◽  
Author(s):  
Alexander Köthe ◽  
Robert Luckner
Keyword(s):  
Rigid Body ◽  
Flight Control ◽  
Reference Model ◽  
Equations Of Motion ◽  
Unmanned Aircraft ◽  
Control Law ◽  
Eigenstructure Assignment ◽  
Control Laws ◽  
Target Model ◽  
Alternative Technologies

AbstractUnmanned aircraft used as high-altitude platform system has been studied in research and industry as alternative technologies to satellites. Regarding actual operation and flight performance of such systems, multibody aircraft seems to be a promising aircraft configuration. In terms of flight dynamics, this aircraft strongly differs from classical rigid-body and flexible aircraft, because a strong interference between flight mechanic and formation modes occurs. For unmanned operation in the stratosphere, flight control laws are required. While control theory generally provides a number of approaches, the specific flight physics characteristics can be only partially considered. This paper addresses a flight control law approach based on a physically exact target model of the multibody aircraft dynamics rather than conventionally considering the system dynamics only. In the target model, hypothetical spring and damping elements at the joints are included into the equations of motion to transfer the configuration of a highly flexible multibody aircraft into one similar to a classical rigid-body aircraft. The differences between both types of aircraft are reflected in the eigenvalues and eigenvectors. Using the eigenstructure assignment, the desired damping and stiffness are established by the inner-loop flight control law. In contrast to other methods, this procedure allows a straightforward control law design for a multibody aircraft based on a physical reference model.

Sign in / Sign up

Export Citation Format

Share Document