A vertical takeoff (VTOL) aircraft is an inherently unstable vehicle and requires an automatic stabilization system. An attitude stabilization system for the K-16B U.S. Army VTOL aircraft has been designed and is shown in block diagram form in Figure P9.7 [16]. At 40 knots, the dynamics of the vehicle are approximately represented by the transfer function
The actuator and filter are represented by the transfer function
(a) Obtain the Bode diagram of the loop transfer function L(s) = Gc(s)Gis)H(s) when the gain is K1 = 2. (b) Determine the gain and phase margins of this system, (c) Determine the steady-state error for a wind disturbance of Td(s) = 1/s. (d) Determine the maximum amplitude of the resonant peak of the closed-loop frequency response and the frequency of the resonance, (e) Estimate the damping ratio of the system from Mpω and the phase margin.
