Advances in aircraft flight control

442 Pages·2018·30.197 MB·English

by  Tischler, Mark Brian

Advances in
Aircraft Flight Control

Advances in
Aircraft FBght
Control
Edited by
MARK B. TISCHLER
Taylor ^F rancis
^ Publishers since Ì79H
UK Taylor & Francis, Ltd., 11 New Fetter Lane, London EC4P 4EE
USA Taylor & Francis, 325 Chestnut Street, Philadelphia, PA 19106
Copyright © Mark B. Tischler 1996
All rights reserved. No part of this publication may be reproduced in a retrieval system,
or transmitted, in any form or by any means, electronic, electrostatic, magnetic tape,
mechanical, photocopying, recording or otherwise, without the prior permission of the
copyright owner.
British Library Cataloguing in Publication Data
A catalogue record for this book is available from the British Library.
ISBN 07484 0479 1
Library of Congress Cataloguing in Publication Data are available
Cover design by Amanda Barragry
Typeset in Times 10/12pt by Santype International Limited, Salisbury, Wilts
Printed by Great Britain by T. J. Press (Padstow) Ltd, Cornwall
Contents
Series Introduction Vll
Foreword ix
List of Contributors XV
Part One Specification and Validation Methods
1 Handling-qualities specification - a functional requirement for the flight
control system
R. H, Hoh and D. G. Mitchell
2 System identification methods for aircraft flight control development
and validation 35
M. B, Tischler
Part Two Rotorcraft and V/STOL 71
3 A high bandwidth control system for the helicopter in-flight simulator
ATTHeS - modelling, performance and applications 73
W. von Griinhagen, G. Bouwer, H.-J. Pausder, F. Henschel and J. Kaletka
4 Advanced flight control research and development at Boeing Helicopters 103
K. H. Landis, J. M. Davis, C. Dabundo and J. F. Keller
5 Application of nonlinear inverse methods to the control of powered-lift
aircraft over the low-speed flight envelope 143
J. A. Franklin
6 Flight control and handling research with the VAAC Harrier aircraft 159
G. T. Shanks, S. L, Gale, C. Fielding and D. V, Griffith
Contents
Part Three Transport Aircraft 187
7 The design and development of flying qualities for the C-17 military
transport airplane 189
E. R. Kendall
8 Fly-by-wire for commercial aircraft: the Airbus experience 211
C. Favre
9 Practical control law design for aircraft using multivariable techniques 231
J. D. Blight, R, L. Dailey and D. Gangsaas
Part Four High-performance Aircraft 269
10 Lavi flight control system 271
M. Shmul, E. Erenthal and M. Attar
11 Digital autopilot design for combat aircraft in Alenia 295
A. Tonon and P. L. Belluati
12 Development and flight experience of the control laws and the
aeroservoelastic solution in the Experimental Aircraft Programme (EAP) 321
A. McCuish and B. Caldw^ell
13 X-29 flight control system: lessons learned 345
R. Clarke, J. J. Barken, J. T. Bosworth and J. E. Bauer
14 Practical aspects of the design of an integrated flight and propulsion
control system 369
D. J. Moorhouse and K. D. Citurs
15 Control law design and flight test results of the experimental aircraft
X-31A 391
H. Beh, G. Hofinger and P. Huber
Index 413
VI
Series Introduction
Control systems has a long and distinguished tradition stretching back to
nineteenth-century dynamics and stability theory. Its establishment as a major
engineering discipline in the 1950s arose, essentially, from Second World War driven
work on frequency response methods by, amongst others, Nyquist, Bode and
Wiener. The intervening 40 years has seen quite unparalleled developments in the
underlying theory with applications ranging from the ubiquitous PID controller
widely encountered in the process industries through to high-performance/fidelity
controllers typical of aerospace applications. This development has been increas­
ingly underpinned by the rapid developments in the, essentially enabling, technology
of computing software and hardware.
This view of mathematically model-based systems and control as a mature disci­
pline masks relatively new and rapid developments in the general area of robust
control. Here intense research effort is being directed to the development of high-
performance controllers which (at least) are robust to specified classes of plant
uncertainty. One measure of this effort is the fact that, after a relatively short period
of work, ‘near world’ tests of classes of robust controllers have been undertaken in
the aerospace industry. Again, this work is supported by computing hardware and
software developments, such as the toolboxes available within numerous com­
mercially marketed controller design/simulation packages.
Recently, there has been increasing interest in the use of so-called intelligent
control techniques such as fuzzy logic and neural networks. Basically, these rely on
learning (in a prescribed manner) the input-output behaviour of the plant to be
controlled. Already, it is clear that there is little to be gained by applying these
techniques to cases where mature mathematical model-based approaches yield high-
performance control. Instead, their role is (in general terms) almost certainly going
to lie in areas where the processes encountered are ill-defined, complex, nonlinear,
time-varying and stochastic. A detailed evaluation of their (relative) potential awaits
the appearance of a rigorous supporting base (underlying theory and implementa­
tion architectures for example) the essential elements of which are beginning to
appear in learned journals and conferences.
Vll
Series Introduction
Elements of control and systems theory/engineering are increasingly finding use
outside traditional numerical processing environments. One such general area in
which there is increasing interest is intelligent command and control systems which
are central, for example, to innovative manufacturing and the management of
advanced transportation systems. Another is discrete event systems which mix
numeric and logic decision making.
It is in response to these exciting new developments that the present book series
of Systems and Control was conceived. It will publish high-quality research texts
and reference works in the diverse areas which systems and control now includes. In
addition to basic theory, experimental and/or application studies are welcome, as
are expository texts where theory, verification and applications come together to
provide a unifying coverage of a particular topic or topics.
The book series itself arose out of the seminal text: the 1992 centenary first
English translation of Lyapunov’s memoir On the General Problem of the Stability of
Motion by A. T. Fuller, and was followed by the 1994 publication of Advances in
Intelligent Control by C. J. Harris. The current volume in the series is Intelligent
Control in Biomedicine by D. A. Linkens. Forthcoming titles in the series include
True Digital Control by P. C. Young, A. Chotai and W. Tych, Sliding-Mode Control
by V. Utkin and A Knowledge-Based Approach to Systems Control by G. K. H.
Pang.
E. Rogers
J. O’Reilly
Vlll
Foreword
The highly interdisciplinary nature of the modern aircraft flight control problem
presents a substantial challenge to control engineering. This challenge starts at the
conceptual control system design phase, where the desired system response charac­
teristics required for good handling qualities are specified as a function of aircraft
configuration, mission, flight condition, failure states, and conditions of visibility
including the influence of vision aids. These handling-qualities characteristics
together with the servo-loop requirements for disturbance rejection and stability/
performance robustness across large variations in dynamic characteristics with flight
condition define a formidable set of interdisciplinary design specifications. The
control law architecture and design methodology is selected to meet these complex
requirements. But the practical considerations such as the control engineer’s (or
company’s) design philosophy, and the ease of flight test development and opti­
mization can also have an important influence.
Modern tools for flight control system development are also wide ranging,
requiring an appreciation of several engineering disciplines. Hardware-in-the-loop
simulation, software development/validiation facilities (DF), and advanced ground
and in-flight piloted simulation are used to evaluate the complete system per­
formance for the many flight conditions and control system modes. The nonreal­
time and real-time models used in these tools include complex descriptions of the
aircraft aerodynamics, flight dynamics, propulsion systems, and structural dynamics
characteristics to ensure that the simulation results will be representative of
expected flight behavior. A detailed representation of the digital control system
implementation is also necessary to capture aeroservoelastic and pilot-airframe
coupling phenomena. System identification tools are used to document dynamic
characteristics during development, and later to support control law and handling-
qualities optimization during flight test.
The complexity of modern digital flight control systems and the trend toward
increased technical specialization makes it difficult for one person to acquire the
needed interdisciplinary perspective. More important is that the long time interval
between modern aircraft projects means that new projects may not fully benefit
IX