Stabilising Control for Unsteady Flight in the Proximity of a Planet
by
Sorin Stefan Radnef
National Institute of AeroSpace Research, Bucharest, Iuliu Maniu Street 220, sector 6, 77538

The general problem is to generate the flight control laws so to stabilize the flight behavior for an unsteady evolution showing great deviations from the reference one. As a particular instance, is presented a flight evolution in the proximity of a Planet. The Method used for solving such a problem consider the differential system of mechanical movement which describe the reference flight evolution by side of the (nonlinear) differential system for the perturbed motion as an extended system. The restriction that must be satisfied by the control variables to decrease the state variables deviations are formulated as implicit functions and are used to derive the restriction equations that determine the control laws in an algebraic or differential description; these equations are added to the above mentioned system which is solved in a closed or numerical manner depending on each particular case. This final mathematical system regards the reference control variables, which correspond to the reference evolution, as external known variables, and control variables for the deviated evolution as unknown control variables. The view point to solve the general problem, formulated in the beginning, is similar in some extent to the control problem having a model to follow -model following problem-, but the concrete treatment is quite different. The advantages of the proposed method are the “on line” control of the unsteady flight, the use of the complete nonlinear mathematical model of the mechanical motion, the desired damping for the deviations and the lack of limiting conditions for the values of deviations.

Date received: March 31, 2004

Copyright © 2004 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # canw-27.