Active Helicopter Rotor Control Using Blade-Mounted Actuators

An aeroelastic model of a smart rotor system (which incorporates blade-mounted trailing-edge flap actuators and conventional root pitch actuation) is presented in linear time invariant state space form. The servo-flap deflections are modeled as producing incremental lift and moment variations, so that any linear aerodynamic actuator can be evaluated. This smart rotor model is used to conduct parametric studies involving rotor blade torsional stiffness, center-of-gravity offset, additional actuator mass, and actuator placement. Results on the effects of collective root pitch and servo-flap actuation on rotor thrust response are presented. Active rotor vibration reduction is demonstrated by applying higher harmonic control algorithms to the state space rotor model. Using reasonable servo-flap deflections, a rotor equipped with trailing-edge flaps can provide enough authority to cancel higher harmonic vibration. Thesis Supervisor: Steven R. Hall, Sc.D. Title: Associate Professor of Aeronautics and Astronautics