Nonlinear Non-Cascaded Reference Model Architecture for Flight Control Design with Flight Path Angle Rate Command System
A nonlinear reference model architecture motivated by dynamic inversion based flight control is introduced. As a novel feature, only one integrated reference model is used to provide reference commands, for longitudinal axis: the flight path angle, vertical load factor and pitch rate, while admitting flight path rate command as input; for lateral axis, bank angle and roll rate; for directional axis, lateral load factor and yaw rate. Flight dynamics, actuator dynamics with rate and position limits, and envelope protections could also be incorporated in a straight forward way in one reference model. One advantage of this non-cascaded reference model is that at least attitude of the reference re-sponse could be restored and flied at an early stage of the flight control system design cycle. The second feature is that the reference model is parameterized, allowing the opportunity of updating the knowledge of aircraft dynamics (perhaps damaged) and flying qualities design. With these two aspects, the physical consistency in terms of the reference commands among different channels and reference commands reasonable with respect to true aircraft dynamics could be assured. Although designed for General Aviation aircraft, the framework could be generalized for other aircrafts considering only rigid body dynamics.