Flight Controller Design with Nonlinear Aerodynamics, Large Parameter Uncertainty, and Pilot Compensation

摘要

Nonlinear Quantitative Feedback Theory (QFT), developed by Dr. Isaac Horowitz, is used to design a flight control system for the YF-16 aircraft. Upon completing this stability augmentation system (SAS) additional compensation is added to reduce pilot workload while improving handling qualities. The YF-16 uncertain plant is simulated with C (a blend of normal acceleration at pilot station and pitch rate) as the controlled output. The simulation includes the full siz degree of freedom nonlinear dynamic equations of motion and aerodynamic data throughout the entire subsonic flight envelope. A technique is presented which enables the uncertain nonlinear YF-16 to be represented as a set of linear timer invariant plants which is equivalent to the nonlinear plant with respect to the set of acceptable outputs. Once this set of plants is obtained, a linear QFT controller is synthesized yielding fixed compensation which is extremely insensitive to varying flight conditions. Simulations in the time and frequency domains demonstrate that the desired performance is attained. Further work with real-time man-in-the-loop simulations should be accomplished to expand the area of pilot compensation. Theses. (SDW)