Function Approximation Technique (FAT)-Based Adaptive Feedback Linearization Control for Nonlinear Aeroelastic Wing Models Considering Different Actuation Scenarios

This paper introduces a comprehensive study on vibration damping of a lumped aeroelastic wing model with translational linear and torsional nonlinear spring elements considering different actuation scenarios. The wing models have two degrees of freedom (DoFs) representing translational and torsional oscillations. On the other hand, the flap angles represent the control inputs that attempt to regulate the wing vibrations. Depending on the number of flaps designed, three actuation scenarios are investigated including fully actuated, overactuated, and underactuated wing models. For a fully actuated wing system (Scenario 1), conventional adaptive control strategies can be used for damping wing oscillations; however, adaptive approximation control is adopted in this work due to its capabilities for controlling (regulating) the dynamic system in the presence of the unknown system parameters. On the other hand, in the overactuated wing model (Scenario 2), the wing system has more control inputs than the DoFs and hence infinite solutions for the control input response are obtained. The Pseudoinverse matrix is a powerful tool to resolve this problem. In Scenario 3, the control inputs are less than the DoFs and hence a partial feedback linearization control strategy with an adaptive approximation compensator is used for regulation purposes; however, the internal dynamics of the underactuated wing system should be stable. Simulation experiments are performed to prove the effectiveness of control methods of the investigated scenarios.