Minimax LQG controller design for nanopositioners

Author

Das, Sajal K. ; Rehman, Obaid Ur ; Pota, Hemanshu R. ; Petersen, Ian R.

Author_Institution

Sch. of Eng. & Inf. Technol. (SEIT), Univ. of New South Wales at the Australian Defence Force Acad. (UNSW@ADFA), Canberra, ACT, Australia

fYear

2014

fDate

24-27 June 2014

Firstpage

1933

Lastpage

1938

Abstract

A design and experimental implementation of a minimax linear-quadratic-Gaussian (LQG) controller to damp the resonant modes of a piezoelectric tube scanner (PTS) used in most commercial atomic force microscopes is presented in this paper. The controller design is presented to account two uncertainties in the system which arises due to (a) the spill over dynamics of the PTS at high frequencies and (b) changes in resonance frequency of the scanner which occur due to the various loads on the scanner or due to the environmental factors such as temperature and humidity. The effectiveness of the proposed controller is presented by experimental results and the experimental results show that, the proposed controller is able to flatten down the frequency response of the PTS by providing 18 dB damping of the first resonant mode of the scanner.

Keywords

atomic force microscopy; control system synthesis; linear quadratic Gaussian control; minimax techniques; nanopositioning; piezoelectric devices; PTS; atomic force microscopes; environmental factors; frequency response; minimax LQG controller design; minimax linear-quadratic-Gaussian controller; nanopositioners; piezoelectric tube scanner; resonance frequency; resonant modes; temperature; Riccati equations; Uncertainty;

fLanguage

English

Publisher

ieee

Conference_Titel

Control Conference (ECC), 2014 European

Conference_Location

Strasbourg

Print_ISBN

978-3-9524269-1-3

Type

conf

DOI

10.1109/ECC.2014.6862321

Filename

6862321