Fault Tolerant Control Design for the Longitudinal Aircraft Dynamics using Quantitative Feedback Theory

Flight control laws of modern aircraft are scheduled with respect to flight point parameters. The loss of the air data measurement system implies inevitably the loss of relevant scheduling information. A strategy to design a fault tolerant longitudinal flight control system is proposed which can accommodate the total loss of the angle of attack and the calibrated airspeed measurements. In this scenario the described robust longitudinal control law is employed ensuring a control performance as close as possible to the nominal one. The controller is designed using quantitative feedback theory applied to the linear approximation of the longitudinal aircraft dynamics and is tested on a nonlinear high fidelity simulation model of a civil aircraft