Smart aerodynamic control surface actuator

Integral control surfaces in rear sections of airfoils can be used to actively control camber. This has potential applications in individual blade cyclic control of helicopters and in aeroelastic control of fixed-wing aircraft. When analyzed as actuators, integral control surfaces will have a characteristically misbehaved frequency response function (FRF). Taking tip displacement as a result of a force input, one would expect either highly peaked resonances characteristic of such a substructure or large areas of very low response depending on what part of the frequency domain the observation is made. In this paper, active control is used locally to convert the FRF of a proposed integral actuator into a more favorable flat-gain FRF in a frequency range of interest. This is accomplished while still exploiting at least some of the gain of the open loop first structural resonance. Both experiment and analysis are presented.