Passive shunt damping of a piezoelectric stack nanopositioner

The speed and accuracy of nanopositioning systems is heavily influenced by the presence of lightly damped mechanical resonances. In this work, an electrical impedance is connected in series with the driving piezoelectric stack actuator to damp the first mechanical resonance. The electrical shunt is shown to act equivalently to an output feedback controller except that no sensor is required. A simple inductor-resistor shunt circuit is demonstrated to damp the first mechanical resonance of a high-speed nanopositioner by 19.6 dB. The technique of shunt damping is low-cost, simple, guaranteed to be stable, and significantly improves the system response.