Lucas, Amy Marie (2009-08). Gust Load Alleviation for an Aeroelastic System Using Nonlinear Control. Master's Thesis. Thesis uri icon


  • The author develops a nonlinear longitudinal model of an aircraft modeled by

    rigid fuselage, tail, and wing, where the wing is attached to the fuselage with a torsional

    spring. The main focus of this research is to retain the full nonlinearities

    associated with the system and to perform gust load alleviation for the model by

    comparing the impact of a proportional-integral- lter nonzero setpoint linear controller

    with control rate weighting and a nonlinear Lyapunov-based controller. The

    four degree of freedom longitudinal system under consideration includes the traditional

    longitudinal three degree of freedom aircraft model and one additional degree

    of freedom due to the torsion from the wing attachment. Computational simulations

    are performed to show the aeroelastic response of the aircraft due to a gust load

    disturbance with and without control. Results presented in this thesis show that

    the linear model fails to capture the true nonlinear response of the system and the

    linear controller based on the linear model does not stabilize the nonlinear system.

    The results from the Lyapunov-based control demonstrate the ability to stabilize the

    nonlinear response, including the presence of an LCO, and emphasize the importance

    of examining the fully nonlinear system with a nonlinear controller.

publication date

  • August 2009
  • August 2009