Active flutter suppression design of a wing based on sliding mode observer

Active flutter suppression (AFS) is a worldwide well proposed solution for the flutter of aircraft, which plays an important role in modern aircraft design. Many studies have shed some light on the AFS usage of sliding mode control strategy and the sliding mode observer, acting on two-dimensional wings. Herein, a wind-tunnel model of an actual wing which has two tailing-edge flaps is selected to examine the effectiveness of a low-order sliding mode observer which will be applied to AFS design of 3D wing. This observer has superior performance and distinctive features. However, the traditional complicated design routine limits its application to high-order objects. A new simplified design procedure is proposed by using a gain matrix of the Kalman filter in linear quadratic Gaussian (LQG) method. Then, considering the physical property of aeroelasticity, the new method can be put into practice theoretically. Comparison analyses are given. The results indicate that the sliding mode observer method has a better noise resistance ability than the LQG method.