TY  - JOUR
TI  - LONGITUDINAL STABILITY ANALYSIS OF A UAV UNDER THE UNCERTAINTY OF TWO STABILITY DERIVATIVES
AB  - The longitudinal stability of an aircraft is analyzed using root locations of the transfer function’s denominator (the characteristicequation). This transfer function is obtained by linearizing aircraft dynamic model at a certain operation point (altitude andspeed). However, aircraft have varying stability derivatives, therefore dynamic behavior, for different flight phases such as takeoff,cruise, and landing. Thus the stability analysis of the characteristic equation can be said to be valid only for a single flight condition.In fact, stability derivatives vary with flight conditions, so an analysis that includes all possible stability derivatives in the flightenvelope is required to guarantee stability. In this study, the two most variable stability derivatives in the transfer function weretaken as uncertain parameters. Gridding these two parameters to check the stability of the unmanned aerial vehicle for all possibleflight conditions is a possible method, but it is very time-consuming, and it cannot assure the stability theoretically. A new simpleapproach is developed by using the Edge and Bialas theorems, which guarantees stability despite the uncertainty of two stabilityderivatives. The problem is reduced to the analysis of four polynomials. With the eigenvalues of just four polynomials, thestability characteristics of an airplane for a given flight envelope can be easily determined.
AU  - KAYNAK, Ünver
AU  - ÖZNALBANT, Zafer
AU  - KAVSAOĞLU, MEHMET ŞERİF
AU  - Özdemir, Uğur
DO  - 10.18038/aubtda.405179
PY  - 2018
JO  - Eskişehir Technical University Journal of Science and and Technology A- Applied Sciences and Engineering
VL  - 19
IS  - 4
SN  - 2667-4211
SP  - 831
EP  - 843
DB  - TRDizin
UR  - http://search/yayin/detay/326919
ER  -