Title :
Resonant controller for fast atomic force microscopy
Author :
Das, Sajal K. ; Pota, Hemanshu R. ; Petersen, Ian R.
Author_Institution :
Sch. of Eng. & Inf. Technol. (SEIT), Univ. of New South Wales at Australian Defence Force Acad. (UNSW@ADFA), Canberra, ACT, Australia
Abstract :
The imaging performance of the atomic force microscope (AFM) in higher scanning speed is limited to the one percent of the first resonant frequency of it´s scanning unit i.e., piezoelectric tube scanner (PTS). In order to speed up the functioning of the AFM for high speed imaging, a resonant controller with an integral action has been applied in the both x and y axis of the PTS for damping the resonant mode of the scanner and improve the tracking performance. The overall closed-loop system with this scheme has higher bandwidth with improved gain and phase margin than the existing PI controller. It can reduce the cross coupling of the scanner and allows faster scanning. To measure the performance improvement of the proposed scheme a comparison has been made between the proposed controller scanned image and the existing AFM PI controller scanned image.
Keywords :
PI control; atomic force microscopy; closed loop systems; AFM PI controller scanned image; PTS; closed-loop system; cross coupling reduction; fast atomic force microscopy; gain margin; high speed imaging; integral action; performance improvement; phase margin; piezoelectric tube scanner; resonant controller; resonant frequency; scanning speed; scanning unit; tracking performance; Couplings; Damping; Electron tubes; Frequency measurement; Frequency response; Mathematical model; Resonant frequency;
Conference_Titel :
Decision and Control (CDC), 2012 IEEE 51st Annual Conference on
Conference_Location :
Maui, HI
Print_ISBN :
978-1-4673-2065-8
Electronic_ISBN :
0743-1546
DOI :
10.1109/CDC.2012.6426563