Active vibration control of a smart fin

Abstract

This paper summarizes the design and wind tunnel experimental verifications of robust H 1e controllers for active vibration suppression of a dynamically scaled F-18 vertical smart fin. The smart fin consists of a cantilevered aluminium plate structure with surface bonded piezoelectric (Lead-Zirconate-Titanete, PZT) patches, Integrated Circuit Piezoelectric (ICP) type accelerometers and strain gauges. For H 1e controller design, the transfer function of the fin was first estimated outside the wind tunnel. Then, experiments were carried out to determine the aeroelastic characteristics of the smart fin at free flow and vortical (i.e. buffet) flow conditions. Variable air speeds and Angle of Orientations (AoO) were considered in both flow conditions. Significant shifts in vibration frequencies and the damping ratios were observed at the various values of airspeed and AoO. Taking into account these variations, the H 1e controllers were designed to suppress the fin's buffeting response at the first and second bending and first torsional modes. A second set of wind tunnel experiments was conducted to verify the performance of the designed H 1e controllers at various flow scenarios. Successful vibration suppression levels were obtained within the desired frequency intervals.Peer reviewed: YesNRC publication: Ye