FULL ENVELOPE FLIGHT CONTROL-SYSTEM DESIGN USING QUALITATIVE FEEDBACKTHEORY

A controlled plant's characteristics can vary widely throughout its op erational envelope. This is a major problem in nominal plant-based con trol system design, Hence, gain scheduling is often used for full enve lope design. In this paper, it is proposed to address the plant's vari ability using robust control design concepts, minimizing the need for gain scheduling, In particular, the frequency-domain-based quantitativ e feedback theory multiple input multiple output robust controls desig n method is employed for the synthesis of a full envelope flight contr ol system for an F-16 aircraft derivative, Qualitative feedback theory addresses structured uncertainty that is caused by full envelope oper ation. Thus, qualitative feedback theory robust control is particularl y suited for full envelope controller design, Compensators and prefilt ers for the aircraft's pitch and lateral/directional channels are desi gned to meet level 1 flying qualities specifications, and these design s are validated using simulations.