Hierarchical Adaptive Controller for a Nonlinear Aeroelastic Wing Section with Multiple Control Surfaces

This paper concerns the design of an adaptive controller for suppressing aeroelastic vibrations on a nonlinear wing section with leading- and trailing-edge flaps as the actuators. While a single flap under adaptive control can suppress vibrations, the response rate is limited by the system zero dynamics. The adaptive controller pursued here synergistically utilizes both leading-and trailing-edge flaps to completely determine the closed-loop system response. The proposed algorithm addresses the problem of designing a singularity-free adaptive controller when the control inputs are coupled via an input gain matrix whose parameters are uncertain. The stability result that is achieved here is global asymptotic tracking. Simulation results demonstrate the efficacy of the MIMO control toward suppressing flutter and limit cycle oscillations (LCOs) as well as reducing the vibrational level in the subcritical flight speed range. Pertinent conclusions have been outlined.