Dynamic response control of rotating thin-walled composite blade exposed to external excitations

A study of the dynamic control of a rotating blade subjected to external excitations is presented. A tapered thin-walled beam of closed cross-section contour with fiber-reinforced composite material is used for present study. Since a rotating blade may be exposed to a severe environment such as high angular velocity, large external load, and so on, robust control methodology is implemented to extend the blade's life and improve its efficiency. To verify the performance of the state estimator, a sliding mode observer is introduced, and an associated robustness test is conducted in case of model uncertainty. A robust control methodology using sliding mode control in conjunction with a sliding mode observer is implemented, and its performance toward reducing the flapping dynamic responses of a rotating blade under initial conditions and various external loadings such blast load and distributed load is demonstrated. Moreover, its control performance is compared with that of the conventional linear quadratic Gaussian implementation.