Research: Aerospace

Limit Cycle Oscillation Control


Introduction

In modern fighter aircraft, limit cycle oscillations (LCO) manifest as an anti-symmetric, non-divergent periodic twisting and bending motion of the wings. LCO can affect the pilot's ability to perform tasks such as reading gauges and the heads up display (HUD). Typical solutions involve avoiding certain flight conditions and delaying the release of ordnance. The objective of this project is to develop a control strategy that augments current flight controllers to suppress LCO behavior while remaining robust to modeling uncertainties and exogenous disturbances. The control strategy employed combined a neural network feedforward approximation of the uncertain dynamics with RISE feedback. Simulations with this control structure show fast damping of LCO.

Simulations

Uncontrolled LCO
Uncontrolled LCO

Controlled LCO
Uncontrolled LCO

Video of typical LCO on an F-16
source: http://aeweb.tamu.edu/aeroel/gallery1.html



Publications

B. Bialy, C. Pasiliao, H. Dinh, and W. E. Dixon, "Lyapunov-Based Tracking of Store-Induced Limit Cycle Oscillations in an Aeroelastic System," ASME Dynamic Systems and Control Conference, Ft. Lauderdale, FL, 2012.