How Fast Can a PiezoActuator Expand? Fast response is one of thecharacteristic features of piezo actuators. A rapid drive voltage change results in a rapid posi- tion change. This property is especially welcome in dynamic applications such as scanningmicroscopy, image stabiliza-tion, switching of valves/shut- ters, shock-wave generation, vibration cancellation systems, etc.A piezo actuator can reach itsnominal displacement inapproximately 1/3 of the period of the resonant frequency, pro- vided the controller can deliver the necessary current. If not compensated by appropriate measures (e.g. notch filter,InputShaping (Equation 14) Minimum rise time of a piezoactuator (requires an amplifier with sufficient output current and slew rate). where:T
min = time [s]f
=resonant frequency[Hz]] Example: A piezo translatorwith a 10 kHz resonant frequen- cy can reach its nominal dis- placement within 30 µs.
® , see PI main catalog page4-33) in the servo- loop, such rapid expansion willbe accompanied by significant overshoot.
Response of an undamped, lever-amplified piezo actuator (low resonant frequency) to a rapid drive-voltage change. This behaviorcan be prevented by intelligent control techniques or position servo control © PI 1998–2006. Subject to change without notice. This data sheet is superseded by any newrelease. The newest release is available for download at www.pi.ws. 06/10/30.0 50