High speed laser scanning microscopy by iterative learning control of a galvanometer scanner

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• 作者：Han Woong Yoo ; ^{yoo@acin.tuwien.ac.at" class="auth_mail" title="E-mail the corresponding author} ; Shingo Ito ; Georg Schitter
• 关键词：Iterative learning control ; Galvanometer scanner ; Non-minimum phase zeros ; Scanning laser microscopy ; Precision motion control
• 刊名：Control Engineering Practice
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：50
• 期：Complete
• 页码：12-21
• 全文大小：1192 K

文摘

Iterative learning control (ILC) for a galvanometer scanner is proposed to achieve high speed, linear, and accurate bidirectional scanning for scanning laser microscopy. A galvanometer scanner, as a low stiffness actuator, is first stabilized with a feedback control compensating for disturbances and nonlinearities at low frequencies, and ILC is applied for the control of the fast scanning motion. For stable inversion of the non-minimum phase zeros, a time delay approximation and a zero phase approximation are used for design of ILC, and their attainable bandwidths are analyzed. Experimental results verify the benefits of ILC of its wide control bandwidth, enabling a faster, more linear, and more accurate scanning without a phase lag and a gain mismatch. At the scan rate of 4112 lines per second, the root mean square (RMS) error of the ILC can be reduced by a factor of 73 in comparison with the feedback controlled galvanometer scanner of the commercial system.