Active control of V/STOL aircraft

Hopper, DJF

Abstract

Vertical/Short Take-Off arid Landing (V/STOL) fighter aircraft are
characterised by increased control complexity caused by the extra degree
ol freedom. This can result in a high pilot workload which may be
alleviated with the careful application of active flight control.
However, the advent of control configured vehicles demands that the
controller design must be part of a fully integrated and iterative
aircraft design; hence it must allow the two-way flow of design
information.
In this thesis a suitable controller (leSign method is developed to solve
this two-fold problem.
The method is based upon a singular perturbation analysis which is used
to expose the underlying dynamics of a closed-loop state-space system.
developments are described which allow high-order, dynamically
complex parasitics, such as actuators, to be included in the design.
}urtherrnore, the method gives the designer insight into the problem
allowing tuning and engineering trade-offs to be performed intelligently
with a two-way flow of design information. The end result is a robust
high-gain multivariable controller.
In order fully to develop arid analyse the method it has been applied to
a representative non-linear time-varying aircraft simulation model. This
LS supplied by the Royal Aerospace Establishment, Bedford. The necessary slate-space matrices are otitairted by lirLearisirig the model at several
differertt flight cases. This occurs over a wide flight envelope, from
hover to 300 Kts, and consequently the multivariable control laws are
implemented using gain scheduling.
Finally, task tailored control and handling qualities requirements are
derived for a V/STOL aircraft in the form of a design brief. This design
brief is then fulfilled by designing a controller which alleviates pilot
workload during transitions from jet-borne to fully wing-borne flight
(and vice versa).

Citation

Hopper, D. Active control of V/STOL aircraft. (Thesis). University of Salford

• Thesis Type: Thesis
• Deposit Date: Sep 23, 2011
• Publicly Available Date: Sep 23, 2011
• Award Date: Jan 1, 1990