Tracking control of a nanopositioner using complementary sensors

Piezoelectric tube actuators are widely used in atomic force and scanning tunneling microscopy (STM) for nanoscale positioning. There has been a consistent effort to increase the scan speed of these actuators using feedback control techniques. A feedback controller requires a measurement of the scan...

Full description

Bibliographic Details
Main Authors:	Mahmood, Iskandar Al-Thani, Moheimani, S.O. Reza, Liu, Kexiu
Format:	Article
Language:	English
Published:	Institute of Electrical and Electronics Engineers (IEEE) 2009
Subjects:	Q Science (General) TJ212 Control engineering
Online Access:	http://irep.iium.edu.my/5210/ http://irep.iium.edu.my/5210/ http://irep.iium.edu.my/5210/ http://irep.iium.edu.my/5210/1/Tracking_Control_of_a_Nanopositioner_Using_Complementary_Sensors.pdf

id	iium-5210
recordtype	eprints
spelling	iium-52102012-02-10T02:38:51Z http://irep.iium.edu.my/5210/ Tracking control of a nanopositioner using complementary sensors Mahmood, Iskandar Al-Thani Moheimani, S.O. Reza Liu, Kexiu Q Science (General) TJ212 Control engineering Piezoelectric tube actuators are widely used in atomic force and scanning tunneling microscopy (STM) for nanoscale positioning. There has been a consistent effort to increase the scan speed of these actuators using feedback control techniques. A feedback controller requires a measurement of the scanner's deflection, which is often provided by a capacitive sensor. Such measurements are corrupted by sensor noise, typically in the order of 20 pm/ radicHz rms. Over a bandwidth of 10 kHz, this translates into an rms noise of 2 nm, clearly inadequate for applications that require subnanometer positioning accuracy, e.g., STM. In this paper, we illustrate how the strain voltage induced in a free electrode of the scanner can be used as an additional displacement signal. The noise level corresponding to the strain signal is about three orders of magnitude less than that of a capacitive sensor, making it an ideal choice for nanopositioning applications. However, it cannot be used for dc and low-frequency measurements. A two-sensor-based controller is designed to use the capacitive sensor signal at low frequencies, and the strain displacement signal at high frequencies. By limiting the capacitive sensor feedback loop bandwidth to less than 100 Hz, the rms value of the noise is reduced to well below 1 nm. For almost the same noise level, the two-sensor-based control structure achieves a closed-loop bandwidth of more than three times that of the single-sensor-based controller. Institute of Electrical and Electronics Engineers (IEEE) 2009-01 Article PeerReviewed application/pdf en http://irep.iium.edu.my/5210/1/Tracking_Control_of_a_Nanopositioner_Using_Complementary_Sensors.pdf Mahmood, Iskandar Al-Thani and Moheimani, S.O. Reza and Liu, Kexiu (2009) Tracking control of a nanopositioner using complementary sensors. IEEE Transactions on Nanotechnology, 8 (1). pp. 55-65. ISSN 1536-125X http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=7729 10.1109/TNANO.2008.2005183
repository_type	Digital Repository
institution_category	Local University
institution	International Islamic University Malaysia
building	IIUM Repository
collection	Online Access
language	English
topic	Q Science (General) TJ212 Control engineering
spellingShingle	Q Science (General) TJ212 Control engineering Mahmood, Iskandar Al-Thani Moheimani, S.O. Reza Liu, Kexiu Tracking control of a nanopositioner using complementary sensors
description	Piezoelectric tube actuators are widely used in atomic force and scanning tunneling microscopy (STM) for nanoscale positioning. There has been a consistent effort to increase the scan speed of these actuators using feedback control techniques. A feedback controller requires a measurement of the scanner's deflection, which is often provided by a capacitive sensor. Such measurements are corrupted by sensor noise, typically in the order of 20 pm/ radicHz rms. Over a bandwidth of 10 kHz, this translates into an rms noise of 2 nm, clearly inadequate for applications that require subnanometer positioning accuracy, e.g., STM. In this paper, we illustrate how the strain voltage induced in a free electrode of the scanner can be used as an additional displacement signal. The noise level corresponding to the strain signal is about three orders of magnitude less than that of a capacitive sensor, making it an ideal choice for nanopositioning applications. However, it cannot be used for dc and low-frequency measurements. A two-sensor-based controller is designed to use the capacitive sensor signal at low frequencies, and the strain displacement signal at high frequencies. By limiting the capacitive sensor feedback loop bandwidth to less than 100 Hz, the rms value of the noise is reduced to well below 1 nm. For almost the same noise level, the two-sensor-based control structure achieves a closed-loop bandwidth of more than three times that of the single-sensor-based controller.
format	Article
author	Mahmood, Iskandar Al-Thani Moheimani, S.O. Reza Liu, Kexiu
author_facet	Mahmood, Iskandar Al-Thani Moheimani, S.O. Reza Liu, Kexiu
author_sort	Mahmood, Iskandar Al-Thani
title	Tracking control of a nanopositioner using complementary sensors
title_short	Tracking control of a nanopositioner using complementary sensors
title_full	Tracking control of a nanopositioner using complementary sensors
title_fullStr	Tracking control of a nanopositioner using complementary sensors
title_full_unstemmed	Tracking control of a nanopositioner using complementary sensors
title_sort	tracking control of a nanopositioner using complementary sensors
publisher	Institute of Electrical and Electronics Engineers (IEEE)
publishDate	2009
url	http://irep.iium.edu.my/5210/ http://irep.iium.edu.my/5210/ http://irep.iium.edu.my/5210/ http://irep.iium.edu.my/5210/1/Tracking_Control_of_a_Nanopositioner_Using_Complementary_Sensors.pdf
first_indexed	2023-09-18T20:13:42Z
last_indexed	2023-09-18T20:13:42Z
_version_	1777407646838554624

Tracking control of a nanopositioner using complementary sensors

Similar Items