Sensitivity reduction and robust tracking with application to aircraft control

An approach for reducing trajectory sensitivity and robust asymptotic tracking for linear feedback systems when there are parameter perturbations and disturbance inputs, is presented. The controller consists of a servocompensator containing the modes of the reference signals and disturbance inputs, a stabilizing feedback loop, and a feed-forward element. Application of the method to the design of a VTOL aircraft flight control system is presented. The use of precompensator allows to perform maneuvers so that the aircraft tracks desired trajectories and the feed-forward signal aids in reducing the trajectory sensitivity to variations of parameters due to change in airspeed, and to wind gust. Simulation results are presented to show the robust tracking, disturbance rejection, and sensitivity reduction capabilities of the flight control system.