Download or read book Adaptive Reconfigurable Control Based on a Reduced Order System Identification for Flutter and Aeroservoelastic Instability Suppression written by and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report documents the design of a reconfigurable adaptive control (RAC) system for flutter/aeroservoelasticity (ASE) instability suppression of battle-damaged aircraft and limit cycle oscillation (LCO) suppression of aircraft/store configurations. With the F/A-18 as a baseline aircraft, rapid suppression of its critical damage/flutter and LCO (at 5.6 and 8.8 Hz) has been successfully demonstrated through eight cases of numerical simulations studied. The developed RAC system is a modular control design in that the flutter/LCO control can readily be combined with the rigid-body flight (RBF) control, thereby minimizing the impact on the existing flight control system for retrofit. The RAC system consists of a newly developed on-line modal parameter estimation (MPE) for system identification and on-line modified model-following reconfigurable (MMFR) algorithm for rapid flutter/LCO control (0.2 and 0.8 sec). A massive screening technique using an expedient nonlinear unsteady transonic method (ZTAIC) to generate plant matrices permits efficient identification of critical damage cases of flutter/ASE instability. Reduced-order techniques using proper orthogonal decomposition (POD) and minimum state (MIST) methods reduce the system to seven states. This allows the on-line algorithm to be operated within fractions of one second. The number of sensor locations are minimized to two at wing-tip for flutter/LCO control; and to four with two additional existing sensors in the fuselage for LCO/RBF dynamic control. Effective control surfaces for all cases considered are found to be the aileron and the trailing-edge flap rather than the leading edge flap. Essential tasks of phase Ii will be performed jointly with Boeing/St Louis with emphasis on nonlinear control analysis including actuator loading, control surface rates, 80Hz software update and software analysis for implementing LCO and flutter controllers in the FSFCC.