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The Strongly Controlled Aircraft

Published online by Cambridge University Press:  07 June 2016

R. D. Milne
Affiliation:
Queen Mary College, University of London
G. D. Padfield
Affiliation:
Queen Mary College, University of London
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Summary

In many flight situations an automatic control is used to minimise the deviation of one or two aircraft motion variables from their trim values. The same effect may be brought about, in certain cases, by pilot action. If the control is very strong it may be imagined that the aircraft motion is kinematically constrained in the sense that the controlled motion variables are actually held irrevocably at their trimmed values throughout a disturbance.

More than fifteen years ago Neumark presented an analytical treatment of startling simplicity which dealt with the motion of an aircraft under strict kinematic constraint. By adopting the concept of kinematic constraint and so eliminating one or more variables the motion of the aircraft is described by a simpler set of equations: yet, clearly, the addition of a control system to the aircraft will, in fact, increase the complexity of the complete set of describing equations. However, there is no doubt that Neumark’s theory does give meaningful and useful results.

The analysis described in this paper shows how the motion of a strongly controlled aircraft can be described in terms of simpler sub-systems and indicates that Neumark’s theory appears as the limiting case of infinite control strength. The role of the pilot in applying strong control is placed in the context of the general theory.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society. 1971

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References

1. Neumark, S. Problems of longitudinal stability below minimum drag speed and theory of stability under constraint. ARC R & M 2983, 1957.Google Scholar
2. Pinsker, W. J. G. Directional stability in flight with bank angle constraint as a condition defining a minimum acceptable value for RAE Technical Report 67 127, June 1967.Google Scholar
3. Milne, R. D. The analysis of weakly coupled dynamical systems. International Journal of Control, Vol. 2, pp. 171-199, August 1965.CrossRefGoogle Scholar
4. Hopkin, H. R. A scheme of notation and nomenclature for aircraft dynamics and associated aerodynamics. RAE Technical Report 66 200, June 1966.Google Scholar
5. Hall, I. A. M. Study of the human pilot as a servo-element. Journal of the Royal Aeronautical Society, Vol. 67, pp. 351-360, June 1963.CrossRefGoogle Scholar
6. Lange, G. W. Man-machine in control systems, pp. 307-311 of Encyclopedia of linguistics, information and control, edited by Meetham, A. R., Pergamon, 1969.Google Scholar
7. Milne, R. D. Control of aircraft as two non-interacting systems, pp. 128-129 of Encyclopaedia of linguistics, information and control, edited by Meetham, A. R., Pergamon, 1969.Google Scholar