Active Control of Vortex-induced Vibrations using a Continuous Sliding Mode Control

paper presents an experimental realization of the Continuous Sliding Mode (CSM) control method. The method is utilized to actively control vortex-induced vibration of a flexible cylinder whose diameter and length are 4.1 cm and 30.0 cm respectively. The cylinder is placed inside a low speed wind tunnel which provides flow speeds between 3.0 m/s and 9.0 m/s. Such flow speeds correspond to a range of Reynolds numbers between 8,000 and 24,900. The experimental performance of the CSM controller is determined at several flow speeds and for different values of the controller parameters in order to demonstrate the merits and capabilities of this robust controller. Particular emphasis is placed on demonstrating the effectiveness of the CSM controller in attenuating the structural vibrations rejecting the vortex-induced excitations; accommodating parameter uncertainty and reducing the fluctuating lift forces.