Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-02T20:32:20.246Z Has data issue: false hasContentIssue false

An optimal control approach for alleviation of tiltrotor gust response

Published online by Cambridge University Press:  27 January 2016

D. Muro
Affiliation:
University Roma Tre, Department of Mechanical and Industrial Engineering, Via della Vasca Navale, Rome, Italy
M. Molica Colella
Affiliation:
University Roma Tre, Department of Mechanical and Industrial Engineering, Via della Vasca Navale, Rome, Italy
J. Serafini
Affiliation:
University Roma Tre, Department of Mechanical and Industrial Engineering, Via della Vasca Navale, Rome, Italy
M. Gennaretti*
Affiliation:
University Roma Tre, Department of Mechanical and Industrial Engineering, Via della Vasca Navale, Rome, Italy

Abstract

The alleviation of gusts effects on a tiltrotor in aeroplane and helicopter operation modes obtained by an optimal control methodology based on the actuation of elevators, wing flaperons and swashplate is examined. An optimal observer for state estimate is included in the compensator synthesis, with the Kalman-Bucy filter applied in the presence of stochastic noise. Tiltrotor dynamics is simulated through an aeroelastic model that couples rigid-body motion with wing and proprotor structural dynamics. An extensive numerical investigation examines effectiveness and robustness of the applied control procedure, taking into account the action of both deterministic and stochastic vertical gusts. In addition, a passive pilot model is included in the aeroelastic loop and the corresponding effects on uncontrolled and controlled gust response are analysed.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2012 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Johnson, J. Optimal control alleviation of tilting proprotor gust response, J Aircr, 1977, 14, pp 301308.Google Scholar
2. Nguyen, K., Betzina, M. and Kitaplioglu, C. Full-scale demonstration of higher harmonic control for noise and vibration reduction on the XV-15 rotor, J American Helicopter Society, 2001, 46, (3), pp 182191.Google Scholar
3. Theodorsen, T. General theory of aerodynamic instability and the mechanism of flutter, NACA Report 496, 1935.Google Scholar
4. Greenberg, J.M. Airfoil in sinusoidal motion in a pulsating stream, NACA TN-1326, 1947.Google Scholar
5. Hodges, D.H. and Dowell, E.H. Nonlinear equation for the elastic bending and torsion of twisted nonuniform rotor blades, NASA TN D-7818, 1974.Google Scholar
6. Friedland, B. Control System Design. An Introduction to State-Space Methods, McGraw-Hill, New York, USA, 1986.Google Scholar
7. Mayo, J.R. The involuntary participation of a human pilot in a helicopter collective control loop, Proceedings of the 15th European Rotorcraft Forum, Amsterdam, The Netherlands, September 1989.Google Scholar
8. Gennaretti, M., Molica Colella, M. and Bernardini, G. Prediction of tiltrotor vibratory loads with inclusion of wing-proprotor aerodynamic interaction, J Aircr, 2010, 47, (1), pp 7179.Google Scholar
9. Gennaretti, M. and Bernardini, G. Aeroelastic response of helicopter rotors using a 3D unsteady aerodynamic solver, Aeronaut J, December 2006, 110, (1114), pp 793801.Google Scholar
10. Gennaretti, M. and Greco, L. Time-dependent coefficient reduced-order model for unsteady aerodynamics of proprotors, J Aircr, 2005, 42, (1), pp 138147.Google Scholar
11. Johnson, W. Analytical model for tilting proprotor aircraft dynamics, including blade torsion and coupled bending modes, and conversion mode operation, NASA TM X-62, 369, 1974.Google Scholar
12. Etkin, B. Dynamics of Atmospheric Flight, Wiley, New York, USA, 1972.Google Scholar
13. Parham, T. Jr and Popelka, D. V22 pilot-in-the-loop aeroelastic stability analysis, Proceedings of the 47th Annual Forum of the American Helicopter Society, Phoenix, Arizona, USA, May 1991.Google Scholar
14. Mclean, D. Automatic Flight Control Systems, Prentice Hall, Englewood Cliffs, New Jersey, 1990.Google Scholar
15. Johnson, W. Analytical modeling requirements for tilting proprotor aircraft dynamics, NASA TN D-8013, 1975.Google Scholar
16. Nixon, M.W. Aeroelastic Response and Stability of Tiltrotors with Elastically-Coupled Composite Rotor Blades, PhD Thesis, University of Maryland, USA, 1993.Google Scholar