Stability Augmentation of an Oblique Wing RC Aircraft

Abstract

This thesis investigates stability augmentation controller design for an oblique wing remote-controlled aircraft. The goal of such research is to stabilize an oblique wing aircraft, despite its strong longitudinal and lateral-directional coupling. Practical significance of our research includes improving performance of an oblique wing craft in the subsonic regime, and making the craft easier to handle if the oblique wing mechanism were to fail between cruise and landing. Emphasis is levied on using N4SID and PEM methods of system identification to construct flight dynamic models from flight test data, rather than from wind tunnel testing. The controller design process is conducted first on a straight wing aircraft using experimental data and a linear quadratic Gaussian regulator. We then extrapolate our controller design to an oblique wing aircraft through the Vortex Lattice Method and a linear quadratic regulator. Both LQ controllers are evaluated for their performance. This paper also covers the design and construction of an experimental oblique wing aircraft, with the intention of flying the craft and implementing our stability augmentation system in future experimental work.