Open-Loop Compensation of Hysteresis and Creep Through a Power-Law Circuit Model

The inverse of a recently proposed hysteresis and creep circuit model is proposed and discussed. The model is particularly suitable for piezoelectric actuators and its inverse can be used for open-loop compensation of the undesired nonlinearities in high-precision applications. The inverse model is defined, analyzed in terms of conditions ensuring a correct compensation, and discretized to provide a digital compensation algorithm suitable for implementation in low-cost programmable devices. Quantitative results on experimental data are provided and discussed, including the compensation on an atomic force microscope.