Partial and full inverse compensation for hysteresis in smart material systems

Smart material transducers employing piezoceramic or magnetostrictive drive components typically exhibit constitutive nonlinearities and hysteresis at moderate to high drive levels. In this paper, we discuss two techniques to compensate for hysteresis in high performance transducers. The first is based on a complete transducer model, and the resulting compensator accommodates both the constitutive nonlinearities and hysteresis inherent to the smart material components. The second technique employs a partial inverse compensator based on anhysteretic models for the material behavior. This accommodates the constitutive nonlinearities but does not incorporate the hysteresis; the latter phenomenon is then addressed through the inclusion of a feedback loop in the controller. The performance of the partial inverse compensator is illustrated in the context of a high force Terfenol-D transducer