QFT based robust/fault tolerant flight control design for a remote pilotless vehicle

Quantitative feedback theory (QFT) was applied successfully to enhance the robust stability and tracking performance of the pitch flight control system for a remote pilotless vehicle within its full flight envelope. The influence of control surface loss or damage to the dynamic derivatives of the aircraft model can be treated as an extension of the model uncertainty robustness problem. QFT is applied to the analysis and design of the fault tolerant flight control system allowing for possible control surface damages.