Control stick force characteristics effect on pilot model parameters

Аuthors

Zaichik L. E.^*, Grinev K. N., Yashin Y. P.^**, Sorokin S. A.

Central Aerohydrodynamic Institute named after N.E. Zhukovsky (TsAGI), 1, Zhukovsky str., Zhukovsky, Moscow Region, 140180, Russia

*e-mail: zaichik@tsagi.ru
**e-mail: yuyash@yandex.ru

Abstract

Notwithstanding the great number of publications concerning pilot models, none of them considers the issue of stick force optimal characteristics selection. It can be explained by the fact that pilot describing function in visual signal tracking is insensitive to loading characteristics variation and does not allow reveal any regularities and their effect on pilot model parameters.

This paper is aimed at studying the effects of stick force characteristics on pilot model and its components, such as limb-manipulator and neuromuscular systems, as well as finding objective proof of loading characteristics, selected by pilots, optimality.

The paper presents recently obtained experimental data on the effect of control stick force characteristics, such as gradient of stick-force damping on pilot model parameters. The effect is analyzed based on pilot model frequency response identified in the problem of compensatory pitch motion tracking. For limb-stick and neuromuscular systems characteristics identification, input strain signal is introduced in addition to visual input signal. Frequency response characteristic computation of various pilot model components was made according to specially developed program, based on fast Fourier transform.

Analysis revealed that the force gradient variation affects neuromuscular frequency response, demonstrating thereby a pilot's adaptation to the stick force variations. Due to this, the limb-stick cutoff frequency of the open-loop system remains constant for the force gradients assessed by the pilot as optimal. The force damping does not have any significant effect on limb-stick system frequency response.

The obtained results are of regular character and contribute to theoretical and practical aspects of pilot models implementation for aircraft sensitivity evaluation.

Keywords:

loading system, control manipulators, force gradient, damping, pilot model, limb-stick system, neuromuscular system

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