scholarly journals Measurement of the Absolute Optical Thickness Distribution of a Mask-blank Glass by a Phase-shifting, Wavelength Tuning Interferometry

2010 ◽  
Vol 76 (2) ◽  
pp. 243-248
Author(s):  
Yangjin KIM ◽  
Kenichi HIBINO ◽  
Youichi BITOU ◽  
Sonko OSAWA ◽  
Naohiko SUGITA ◽  
...  
Keyword(s):  
Optical Thickness ◽  
Thickness Distribution ◽  
Phase Shifting ◽  
Wavelength Tuning ◽  
The Absolute

Simultaneous measurement of surface shape and absolute optical thickness of a glass plate by wavelength tuning phase-shifting interferometry

2012 ◽  
Vol 19 (4) ◽  
pp. 247-253 ◽  
Author(s):  
Kenichi Hibino ◽  
Yangjin Kim ◽  
Sangyu Lee ◽  
Yohan Kondo ◽  
Naohiko Sugita ◽  
...  
Keyword(s):  
Optical Thickness ◽  
Simultaneous Measurement ◽  
Glass Plate ◽  
Phase Shifting ◽  
Wavelength Tuning ◽  
Surface Shape ◽  
Phase Shifting Interferometry

Measurement of absolute optical thickness distribution of a mask-glass by wavelength tuning interferometry

2008 ◽  
Author(s):  
Kenichi Hibino ◽  
Kim Yangjin ◽  
Youichi Bitou ◽  
Sonko Ohsawa ◽  
Naohiko Sugita ◽  
...  
Keyword(s):  
Optical Thickness ◽  
Thickness Distribution ◽  
Wavelength Tuning

A Test-Based Methodology for A Priori Selection of Gain/Phase Relationships in Proportional, Phase-Shifting Control of Combustion Instabilities

2000 ◽  
Author(s):  
Michael A. Vaudrey ◽  
William R. Saunders ◽  
Bryan Eisenhower
Keyword(s):  
Feedback Control ◽  
Frequency Response ◽  
Limit Cycle ◽  
Design Method ◽  
Phase Relationship ◽  
Operating Conditions ◽  
Phase Shifting ◽  
Nonlinear Phenomena ◽  
The Absolute ◽  
Instability Frequency

Feedback control system design, for general single-in-single-out (SISO) applications, requires accurate knowledge of the loop transfer function. Active combustion control design is usually implemented using such SISO architectures, but is quite challenging because the thermoacoustic response results from a relatively unknown, self-excited system and nonlinear processes that must be understood before learning the gain/phase relationship of the system precisely at the instability frequency. However, recent experiments have shown that it is possible to obtain accurate measurements of the relevant loop transfer (frequency response) functions at frequencies adjacent to the instability frequency. Using a simple tube combustor, operating with a premixed, gaseous, burner-stabilized flame, the loop frequency response measurements have been used to develop a methodology that leads to ‘test-based predictions’ of the absolute phase settings and ‘best’ gain settings for a proportional, phase-shifting controller commanding an acoustic actuator in the combustor. The contributions of this methodology are twofold. First, it means that a manual search for the required phase setting of the controller is no longer necessary. In fact, this technique allows the absolute value of controller phase to be determined without running the controller. To the authors’ knowledge, this has not been previously reported in the literature. In addition, the ‘best’ gain setting of the controller, based on this new design approach, can be defined as one that eliminates or reduces the limit cycle amplitude as much as possible within the constraint of avoiding generation of any controller-induced instabilities. (This refers to the generation of ‘new’ peaks in the controlled acoustic pressure spectrum.) It is shown that this tradeoff in limit cycle suppression and avoidance of controller-induced instabilities is a manifestation of the well-known tradeoff in the sensitivity/complementary sensitivity function for feedback control solutions. The focus of this article is limited to the presentation of the design method and does not discuss the detailed nonlinear phenomena that must be understood to determine the optimal gain/phase settings at the limit cycle frequency for a real (versus theoretical) combustor system. A companion paper describes how the proposed design method can be used to generate an AI controller that maintains stabilizing control for a range of changing operating conditions.

scholarly journals Interferometric profile measurement of optical-thickness by wavelength tuning with suppression of spatially uniform error

2018 ◽  
Vol 26 (8) ◽  
pp. 10870 ◽  
Author(s):  
Yangjin Kim ◽  
Kenichi Hibino ◽  
Mamoru Mitsuishi
Keyword(s):  
Optical Thickness ◽  
Wavelength Tuning ◽  
Profile Measurement ◽  
Uniform Error

Principal and Error Analysis on Measurement of Multiple-Surface Interference with Wavelength-Tuning Phase-Shifting

2013 ◽  
Vol 40 (10) ◽  
pp. 1008007 ◽  
Author(s):  
刘勇 Liu Yong ◽  
刘旭 Liu Xu ◽  
任寰 Ren Huan ◽  
姜宏振 Jiang Hongzhen ◽  
杨一 Yang Yi ◽  
...  
Keyword(s):  
Error Analysis ◽  
Phase Shifting ◽  
Wavelength Tuning

Optical thickness measurement of mask blank glass plate by the excess fraction method using a wavelength-tuning interferometer

2013 ◽  
Vol 51 (10) ◽  
pp. 1173-1178 ◽  
Author(s):  
Yangjin Kim ◽  
Kenichi Hibino ◽  
Naohiko Sugita ◽  
Mamoru Mitsuishi
Keyword(s):  
Optical Thickness ◽  
Glass Plate ◽  
Thickness Measurement ◽  
Wavelength Tuning ◽  
Fraction Method
Sign in / Sign up

Export Citation Format

Share Document