Sliding Mode Control Application for Two-Dimensional Active Flutter Suppression.

Abstract

This paper applies a sliding mode controller for suppressing two-dimensional incompressible flow flutter problems in which aerodynamic uncertainties and structural nonlinearity are incorporated. To consider the aerodynamic uncertainties, the steady aerodynamic theory is regarded for the controller design, although the quasi-steady aerodynamic theory is employed in numerical simulation. The structural nonlinearity is included about pitch motion to make a limit cycle oscillation appearing in flutter phenomenon. The control inputs are leading and trailing edge control surfaces. At a velocity of 20m/s, the sliding mode controller is designed to suppress the initial response within 1 second while the uncontrolled wing shows limit cycle oscillation. Furthermore, the sliding mode controller shows robust characteristics in a wide range of the flow velocity. These results indicate that the sliding mode controller is effective for suppressing the flutter problems that have aerodynamic uncertainties and structural nonlinearity.