Augmented systems for a personal aerial vehicle using a civil light helicopter model

This paper presents the implementation of classic augmented control stategies applied to an identified civil light helicopter model in hover. Aim of this study is to enhance the stability and controllability of the helicopter model and to improve its Handling Qualities (HQs) in order to meet those defined for a new category of aircrafts, Personal Aerial Vehicles (PAVs). Two control methods were used to develop the augmented systems, H∞ control and μ-synthesis. The resulting augmented systems were compared in terms of achieved robust stability, nominal performance and robust performance. The robustness was evaluated against parametric uncertainties and external disturbances modeled as real atmospheric turbulences that might be experienced in hover and low speed flight. The main result achieved in this work is that classical control techniques can augment a linear helicopter model to match PAVs responses at low frequencies. As a consequence, the achieved HQs performance resemble those defined for PAVs pilots. However, both control techniques performed poorly for some specific uncertainty conditions demonstrating unsatisfactory performance robustness. Differences, advantages and limitations of the implemented control architectures with respect to the considered requirements are described in the paper.