Diagonal control design for atomic force microscope piezoelectric tube nanopositioners

Atomic Force Microscopes (AFM) are used for generating surface topography of samples at micro to atomic resolutions. Many commercial AFMs use piezoelectric tube nanopositioners for scanning. Scanning rates of these microscopes are hampered by the presence of low frequency resonant modes. When inadve...

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Bibliographic Details
Main Authors: Bhikkaji, Bharath, Yong, Yuen Kuan, Mahmood, Iskandar Al-Thani, Moheimani, S.O. Reza
Format: Article
Language:English
Published: American Institute of Physics (AIP) 2013
Subjects:
Online Access:http://irep.iium.edu.my/29069/
http://irep.iium.edu.my/29069/
http://irep.iium.edu.my/29069/1/Journal%23_RSI_Diagonal_control_design_for_atomic_force_microscope_piezoelectric_tube_nanopositioners.pdf
Description
Summary:Atomic Force Microscopes (AFM) are used for generating surface topography of samples at micro to atomic resolutions. Many commercial AFMs use piezoelectric tube nanopositioners for scanning. Scanning rates of these microscopes are hampered by the presence of low frequency resonant modes. When inadvertently excited, these modes lead to high amplitude mechanical vibrations causing the loss of accuracy, while scanning, and eventually to break down of the tube. Feedback control has been used to damp these resonant modes. Thereby, enabling higher scanning rates. Here, a multivariable controller is designed to damp the first resonant mode along both the x and y axis. Exploiting the inherent symmetry in the piezoelectric tube, the multivariable control design problem is recast as independent single-input single-output (SISO) designs. This in conjunction with integral resonant control is used for damping the first resonant mode.