국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	X-29A LATERAL뺻IRECTIONAL STABILITY AND CONTROL DERIVATIVES EXTRACTED FROM HIGH-ANGLE-OF-ATTACK FLIGHT DATA
저자	Kenneth W. Iliff and Kon-Sheng Charles Wang
Keyword	Aerodynamic characteristics; Forward-swept wing; High angle of attack; Lateral-directional; Maximum likelihood estimation; Parameter identification; Stability and control derivatives; X-29A
URL	http://www.dfrc.nasa.gov/DTRS/1996/PDF/H-2118.pdf
보고서번호	NASA-TP-3664
발행년도	1996
출처	NASA Dryden Flight Research Center
ABSTRACT	The lateral뻚irectional stability and control derivatives of the X-29A number 2 are extracted from flight data over an angle-of-attack range of 4 deg to 53 deg using a parameter identification algorithm. The algorithm uses the linearized aircraft equations of motion and a maximum likelihood estimator in the presence of state and measurement noise. State noise is used to model the uncommanded forcing function caused by unsteady aerodynamics over the aircraft at angles of attack above 15 deg. The results supported the flight-envelope-expansion phase of the X-29A number 2 by helping to update the aerodynamic mathematical model, to improve the real-time simulator, and to revise flight control system laws. Effects of the aircraft high gain flight control system on maneuver quality and the estimated derivatives are also discussed. The derivatives are plotted as functions of angle of attack and compared with the predicted aerodynamic database. Agreement between predicted and flight values is quite good for some derivatives such as the lateral force due to sideslip, the lateral force due to rudder deflection, and the rolling moment due to roll rate. The results also show significant differences in several important derivatives such as the rolling moment due to sideslip, the yawing moment due to sideslip, the yawing moment due to aileron deflection, and the yawing moment due to rudder deflection.