Disturbance-observer-based hysteresis compensation for piezoelectric actuators

Abstract—We present a novel hysteresis compensation method for piezoelectric actuators. We consider the hysteresis nonlinearity of the actuator as a disturbance over a linear system. A disturbance observer (DOB) is then utilized to estimate and compensate for the hysteresis nonlinearity. In contrast to the existing inverse-model-based approach, the DOB-based hysteresis compensation does not rely on any particular hysteresis model, and therefore provides a simple and effective compensation mechanism. We design and fab-ricate a lead magnesium niobate-lead titanate (PMN-PT) piezo-electric actuator for microscale tip-based power sintering process. Experimental validation of the proposed hysteresis compensation is performed on the PMN-PT cantilever piezoelectric actuator. The experimental results demonstrate the effectiveness and efficiency of the approach. Index Terms—Compensation, disturbance observer (DOB), hysteresis, piezoelectric actuator, smart materials. I