UDE based RISE Controller for Active Flutter Suppression of 2D Aerofoil

Abstract

In this paper, active flutter suppression (AFS) of a typical two dimensional aerofoil using a new continuous control technique, called Robust Integral of Signum of Error (RISE) is proposed. The aerofoil model involves two degrees of freedom of motion i.e. pitch and plunge. To enhance the performance of controller in presence of parametric uncertainty and external disturbances, RISE controller has been robustified by designing an uncertainty and disturbance estimator (UDE), which will estimate the total lumped disturbances. The controller does not require any knowledge of plant model or information of uncertainty and disturbances. The efficacy of UDE based RISE controller has been illustrated by simulations using parametric uncertainty, external disturbances, time delay, variation in free stream velocity and constraint of control surface deflection. Results show that proposed controller has enhanced the performance of closed loop system by 68% beyond critical flutter speed. Performance comparison of proposed design has been carried out with UDE based SMC controller which prove the effectiveness of proposed design. Lastly, results indicate that UDE based RISE controller has drastically reduced the rise time, settling time and also, control efforts have been reduced by upto 75% in comparison to UDE based SMC controller.