NONLINEAR MULTIVARIABLE FLIGHT CONTROL OF AIRCRAFT

Innovative design methods are needed for advanced aircraft in response to requirements towards substantial performance improvements. Functio nally and operationally, the aircraft must be considered as the highly coupled non-linear multi-input multi-output system, i.e. the aerodyna mics have to be mapped by non-linear differential or difference equati ons. To improve flying and handling qualities, to increase manoeuvrabi lity and to expand the operating envelope, an innovative optimization procedure is developed to design the constrained controllers for multi -input multi-output aircraft. In particular, a bounded control law is synthesized by employing the Hamilton-Jacobi theory, and the admissibi lity concept is used to study the stability of the resulting closed-lo op system. The developed optimization procedure is applied to a non-li near ninth-order model of an AFTI/F-16 aircraft. A bounded controller is designed, and modelling results are presented to demonstrate the dy namic performance of the resulting closed-loop system.