A new method of synthetic jet actuator-based LCO suppression using an output feedback control strategy

A sliding mode control method is presented in this paper, which is proven to achieve asymptotic limit cycle oscillation (LCO) suppression in unmanned aerial vehicle wings equipped with synthetic jet actuators (SJA). With a focus on applications involving small unmanned aerial vehicles (SUAV) with limited onboard computing resources, the proposed control law is designed to be inexpensively implemented, requiring no adaptive laws, function approximators, or pitching and plunging velocity measurements. Challenges in the control design include input-multiplicative uncertainty due to the parametric uncertainty and nonlinearity that are inherent in the SJA dynamic model. To achieve the result, a sliding mode control strategy is amalgamated with a velocity estimator, which is designed using a bank of dynamic filters. This is the first output feedback control result that achieves asymptotic LCO regulation in the presence of an uncertain, nonlinear SJA dynamic model, without the use of adaptive laws or neural networks. A detailed model of the SUAV dynamics is utilized along with a rigorous Lyapunov-based stability analysis to prove asymptotic regulation of the pitching and plunging displacements, and numerical simulation results are provided to demonstrate the performance of the proposed control design.