HIGH-PERFORMANCE CONTROL OF A PZT SCANNER

A piezoelectric tube of the type typically used for actuation in Scanning Tunneling Microscopes (STMs) and Atomic Force Microscopes (AFMs) is considered. Actuation of this piezoelectric tube is hampered by the presence of a lightly damped low frequency resonant mode. This resonant mode is first identified and then damped using a Positive Velocity and Position Feedback (PVPF) controller, a control technique which is proposed in this paper. Inputs are then shaped such that the closed loop system tracks a raster pattern.