Design of Helicopter Stability Augmentation System Using Eigenstructure Assignment and Minimal Order Functional Observers

This paper details a design study, based on eigenstructure assignment theory, to derive flight control laws for a BO-105 helicopter model to meet the ADS-33E-PRF handling qualities requirements in the pitch and roll axes. Both state variable and output feedback control laws are derived and their relative merits discussed. Minimal order functional observers are used to reconstruct the state variable feedback laws. In all cases stability/performance robustness of the design, using higher order truth models and realistic perturbation models, is demonstrated.