Adaptive Suppression of Wing Flutter Under Actuator Saturation and Time Sampling

Abstract

In the paper, a digital control law for adaptive suppression of the flexural-torsional wing flutter has been developed and analyzed. The control law uses measurements of the wing twist angle (“angle of attack”) and its time derivative. The implicit reference model (IRM) method was used for the synthesis of the so-called “simple adaptive controller” (SAC). A new modification of the adaptive control on the condition of unmodeled servo drive dynamics, time sampling, and boundedness of the control action (the controlling surface deflection) has been developed and studied under parameter variations. The admissible ranges for the values of the mentioned factors are numerically found. The analysis of hidden oscillations in a closed-loop adaptive system caused by the saturation of the control action is carried out. The simulation results demonstrate the robustness of the proposed simple adaptive controller in a wide range of system parameters in the presence of unmodeled system dynamics.