On UAV Robust Nonlinear Control in Presence of Parametric Uncertainties

We examine a new robust nonlinear flight control technology that employs an array of synthetic-jet micro-actuators embedded in UAV wing design in order to completely eliminate moving parts (such as ailerons) thus greatly enhancing maneuverability required for small fixed-wing air vehicles operating, e.g., in tight urban environments. Estimated fast response times are critical in mitigating gust effects while greatly improving flight stability and control. The new controller design is particularly advantageous for high levels of uncertainty and nonlinearity present both in the unsteady flowpath environment and in the embedded actuator’s response. The current work focuses on a benchmark case of flutter control of 2- DOF elastically-mounted airfoil entering limit-cycle oscillations (LCO) due to impinging upstream flow disturbance. Preliminary parametric studies conducted for various SJA excitation amplitudes and frequencies examine the thresholds of the actuator’s control authority to produce a desirable impact.