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Sliding‐mode control of a three‐degrees‐of‐freedom nanopositioner
Author(s) -
Shen JingChung,
Jywe WenYuh,
Liu ChienHung,
Jian YuTe,
Yang Jeffrey
Publication year - 2008
Publication title -
asian journal of control
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.769
H-Index - 53
eISSN - 1934-6093
pISSN - 1561-8625
DOI - 10.1002/asjc.33
Subject(s) - control theory (sociology) , controller (irrigation) , capacitive sensing , compensation (psychology) , nonlinear system , actuator , hysteresis , open loop controller , engineering , control engineering , mode (computer interface) , sliding mode control , tracking (education) , computer science , control (management) , physics , closed loop , artificial intelligence , quantum mechanics , psychoanalysis , agronomy , biology , operating system , psychology , pedagogy , electrical engineering
This paper presents the sliding‐mode control of a three‐degrees‐of‐freedom nanopositioner ( Z , θ x , θ y ). This nanopositioner is actuated by piezoelectric actuators. Capacitive gap sensors are used for position feedback. In order to design the feedback controller, the open‐loop characteristics of this nanopositioner are investigated. Based on the results of the investigation, each pair of piezoelectric actuators and corresponding gap sensors is treated as an independent system and modeled as a first‐order linear model coupled with hysteresis. When the model is identified and the hysteresis nonlinearity is linearized, a linear system model with uncertainty is used to design the controller. When designing the controller, the sliding‐mode disturbance (uncertainty) estimation and compensation scheme is used. The structure of the proposed controller is similar to that of a proportional integral derivative controller. Thus, it can be easily implemented. Experimental results show that 3‐nm tracking resolution can be obtained. Copyright © 2008 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society