The Dependence of the Period and Range of the Oscillations on the Elevator Deflection for the ADMIRE Simplified Model

Abstract

If, during a longitudinal flight with constant forward velocity of an unmanned aerial vehicle (UAV), the automatic flight control system (AFCS) fails and the elevator deflection is not in the safe interval, then the flight becomes oscillatory. In this paper, the dependence of the period and the range of the oscillations of the pitch rate and angle of attack on the elevator deflection of the possible oscillatory flights is numerically investigated, aided by the Scala-based Akka actor system. It is numerically shown that, for a given initial data, the period of oscillations is symmetric with respect to the safe interval and, for an elevator deflection close enough to the boundary of the safe interval, the period is very large while when the value of elevator deflection is far from the boundary of the safe interval the period is small. Additionally, the boundaries of the range of the oscillations of the pitch rate and of the angle of attack decreases when the elevator deflection increases.