Effect of Control Surface Mass Unbalance on the Stability of a Closed-Loop Active Control System
Nissim, E. (1989) Effect of Control Surface Mass Unbalance on the Stability of a Closed-Loop Active Control System. Technical Report NASA TP-2952, Research Engineering, NASA Dryden Flight Research Center.
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Abstract
The effects on stability of inertial forces arising from closed-loop activation of mass-unbalanced control surfaces are studied analytically using inertial energy approach, similar to the aerodynamic energy approach used for flutter suppression. The limitations of a single control surface like a leading-edge (L.E.) control or a trailing-edge (T.E.) control are demonstrated and compared to the superior combined L.E.–T.E. mass unbalanced system. It is shown that a spanwise section for sensor location can be determined which ensures minimum sensitivity to the mode shapes of the aircraft. It is shown that an L.E. control exhibits compatibility between inertial stabilization and aerodynamic stabilization, and that a T.E. control lacks such compatibility. The results of the present work should prove valuable, both for the purpose of flutter suppression using mass unbalanced control surfaces, or for the stabilization of structural modes of large space structures by means of inertial forces.
| EPrint Type: | NASA Technical Publication |
|---|---|
| Keywords: | Active controls, Aeroservoelasticity, Control of space structures, Flutter suppression |
| Subjects: | (31 - 39) Engineering: (39) Structural Mechanics |
| ID Code: | 392 |
| Deposited On: | 16 Febuary 2005 |
| Additional Information: | 26 pages. This research was undertaken while Eli Nissim held a National Research Council—NASA (Ames Research Center, Dryden Flight Research Facility) Research Associateship. The author was on leave from Technion—Israel Institute of Technology. |
