A nonlinear controller for flutter suppression: from simulation to wind tunnel testing

Active control for flutter suppression and limit cycle oscillation of a wind tunnel wing section is presented. Unsteady aerodynamics is modelled with strip theory and the incompressible two-dimensional classical theory of Theodorsen. A good correlation of the stability behaviour between simulation and experimental data is achieved. The paper focuses on the introduction of a nonlinearity in the plunge degree of freedom of an experimental wind tunnel test rig and the design of a nonlinear controller based on partial feedback linearization. To demonstrate the advantages of the nonlinear synthesis on linear conventional methods, a linear controller is implemented for the nonlinear system that exhibits limit cycle oscillations above the linear flutter speed. The controller based on partial feedback linearization outperforms the linear control strategy based on pole placement. Whereas feedback linearization allows to suppress fully the limit cycle oscillations, the pole placement fails to achieve any significant reduction in amplitudes

[1]  Ken Badcock,et al.  Model reduction for linear and nonlinear gust loads analysis , 2013 .

[2]  Alexander F. Vakakis,et al.  Suppression of limit cycle oscillations with a nonlinear energy sink: experimental results , 2006 .

[3]  Sahjendra N. Singh,et al.  ℒ1 adaptive control of a nonlinear aeroelastic system despite gust load , 2013 .

[4]  Andrew J. Kurdila,et al.  Identification and Control of Limit Cycle Oscillations in Aeroelastic Systems , 1999 .

[5]  Daniel G. Cole,et al.  Active Flutter Control with V-Stack Piezoelectric Flap Actuator , 2006 .

[6]  Haiyan Hu,et al.  Designing active flutter suppression for high-dimensional aeroelastic systems involving a control delay , 2012 .

[7]  Jonathan E. Cooper,et al.  Active control for flutter suppression: an experimental investigation , 2013 .

[8]  A. G. Greenhill,et al.  Handbook of Mathematical Functions with Formulas, Graphs, , 1971 .

[9]  A. Isidori.  Nonlinear Control Systems , 1985 .

[10]  Anna Fenech.  At each stage , 2012 .

[11]  D. Owen.  Handbook of Mathematical Functions with Formulas , 1965 .

[12]  N. H. Zimmerman,et al.  Prediction of flutter onset speed based on flight testing at subcritical speeds , 1963 .

[13]  T. Theodorsen.  General Theory of Aerodynamic Instability and the Mechanism of Flutter , 1934 .

[14]  Alexander F. Vakakis,et al.  Suppression of aeroelastic instability with a nonlinear energy sink: Experimental results , 2006 .

[15]  J. Gordon Leishman,et al.  Unsteady lift of a flapped airfoil by indicial concepts , 1994 .

[16]  Chengyu Cao,et al.  L1 adaptive controller for nonlinear systems in the presence of unmodelled dynamics: Part II , 2008, 2008 American Control Conference.

[17]  N. Nichols,et al.  Robust pole assignment in linear state feedback , 1985 .

[18]  Ken Badcock,et al.  Reduction of Nonlinear Models for Control Applications , 2013 .

[19]  Naira Hovakimyan,et al.  L1 Adaptive Output-Feedback Controller for Non-Strictly-Positive-Real Reference Systems: Missile Longitudinal Autopilot Design , 2009 .

[20]  George Platanitis,et al.  Control of a Nonlinear Wing Section Using Leading- and Trailing-Edge Surfaces , 2004 .

[21]  Robert C. Scott,et al.  Aeroservoelastic Wind-Tunnel Tests of a Free-Flying, Joined-Wing SensorCraft Model for Gust Load Alleviation , 2011 .

[22]  R. T. Jones.  The unsteady lift of a wing of finite aspect ratio , 1940 .

[23]  Sangeeth Saagar Ponnusamy,et al.  Adaptive output feedback control of aircraft flexible modes , 2012, CCCA12.

[24]  Ken Badcock,et al.  Nonlinear model reduction for flexible aircraft control design , 2012 .

[25]  Naira Hovakimyan,et al.  Application of ℒ1 adaptive controller to wing rock , 2006 .

[26]  B.H.K. Lee,et al.  ANALYSIS AND COMPUTATION OF NONLINEAR DYNAMIC RESPONSE OF A TWO-DEGREE-OF-FREEDOM SYSTEM AND ITS APPLICATION IN AEROELASTICITY , 1997 .

[27]  Ilya Kolmanovsky,et al.  Gust Load Alleviation Control for Very Flexible Aircraft , 2011 .