Position self-sensing for piezoelectric actuators utilizing an anti-resonant circuit

This article describes a novel position self-sensing technique for piezoelectric actuators utilizing a linear correlation between impedance and stroke of the actuator. By introducing an anti-resonant circuit and superimposing a high frequency evaluation voltage onto the driving voltage, this correlation can be observed via a phase modulation between current and voltage at the evaluation frequency. This approach is expected to reduce the influence of external disturbances on the signal compared to previous studies. For analyzing this technique, an empirical model is fitted to measurement data. This model is utilized to validate the new position self-sensing technique.