ABSTRACT
In this chapter, the PZT (Pb-Zr-Ti) elements in the PZT secondary actuator discussed in Chapter 1 are used as a secondary actuator and a displacement sensor simultaneously with self-sensing actuation (SSA). The used displacement estimation circuit produces an estimated PZT secondary actuator’s displacement with high SNR (signal-to-noise ratio) and nanometer resolution. The estimated displacement is used to decouple the dual-stage system control into two distinct loops for individual sensitivity function optimization as well as to design a robust controller to damp the mechanical structure high-frequency modes such as torsion mode and sway mode.
