Recent advances in material development have brought us a full class of "smart materials." Active noise and vibration control is one application for which these materials are well suited. In fact, for actuators, terfenol-D is the smart material that we believe holds the most promise for many future applications because of its large displacement capabilities. Terfenol-D can also produce large forces compared to other actuator materials The major disadvantage of a terfenol-D actuator, however, is high distortion. A method to linearize this type of nonlinear device will be developed by integrating a nonlinear inverse filter based on a Volterra expansion into a linear type feedback control system. Phase I work will strive to prove that this concept will work by measuring the uncontrolled response of an actuator, designing the control system in real-time on the actuator. Proof of the effectiveness of this type of control approach will be beneficial in controlling any nonlinear system that is stationary. The particular application of the terfenol-D actuator was chosen because of the investigators familiarity with the type of nonlinearities in actuators.
