Design of Robust Controllers for a Multiple Input-Multiple Output Control System with Uncertain Parameters Application to the Lateral and Longitudinal Modes of the KC-135 Transport Aircraft

摘要

A multiple input-multiple output flight control design on the KC-135 aircraft is completed using Quantitative Feedback Theory (QFT). The three degrees-of-freedom model for the lateral mode is reduced to a two degrees-of-freedom model. From this model a robust controller is developed to perform two maneuvers over a wide range of the aircraft flight envelope. The three degrees-of-freedom for the longitudinal mode is then used to develop a robust controller to perform one maneuver. The first and second body bending modes are then added to remove the rigid bosy constraint and a robust control is developed for the non-rigid aircraft. The robust controllers developed for the lateral and longitudinal modes are simulated over a large range of the aircraft's flight envelope. The conclusion drawn from the research is that this method is very effective in designing multiple input-multiple output systems with plant uncertainty.