A nano-displacement measurement system with duo-gratings is analyzed by using optics theory,a math- ematic model for the system is established,and the characteristic of laser Moirésignals is studied through CAD s...A nano-displacement measurement system with duo-gratings is analyzed by using optics theory,a math- ematic model for the system is established,and the characteristic of laser Moirésignals is studied through CAD simu- lation.To improve signal sensitivity and positioning accuracy,two methods of precision positioning are brought for- ward:differential Moirépositioning method and modified Moirépositioning method.A compound control system for precision positioning is set up by combining these 2 Moiréalignment methods,in which the modified Moiréalignment technique is used for coarse alignment and the differential Moiréalignment technique is used for fine alignment,and the system obtains positioning accuracy of±10 nm in±500μm positioning range with shot response time.展开更多
Optical methods such as Twyman-Green interferometry, moiré interferometry, holographic interferometry and speckle interferometry are useful to measure displacement and strain in the full-field of structures. Rece...Optical methods such as Twyman-Green interferometry, moiré interferometry, holographic interferometry and speckle interferometry are useful to measure displacement and strain in the full-field of structures. Recently phase analysis method of fringe patterns obtained by these optical methods becomes popular, and it provides accurate quantitative results in the full-field. In this paper, in order to measure displacement and strain, real-time or high-speed nano-meter displacement measurement methods developed by the authors are introduced. That is, (1) out-of-plane displacement analysis by Twyman-Green interferometry using integrated phase-shifting method using Fourier transform phase-shifting method, (2) simultaneous two-dimensional in-plane displacement analysis by moiré interferometry and (3) out-of-plane displacement analysis by phase-shifting digital holographic interferometry. The theories and applications are shown.展开更多
基金Supported by the National High Technology Research and Development Program of China(863 Program)(2005AA303610)
文摘A nano-displacement measurement system with duo-gratings is analyzed by using optics theory,a math- ematic model for the system is established,and the characteristic of laser Moirésignals is studied through CAD simu- lation.To improve signal sensitivity and positioning accuracy,two methods of precision positioning are brought for- ward:differential Moirépositioning method and modified Moirépositioning method.A compound control system for precision positioning is set up by combining these 2 Moiréalignment methods,in which the modified Moiréalignment technique is used for coarse alignment and the differential Moiréalignment technique is used for fine alignment,and the system obtains positioning accuracy of±10 nm in±500μm positioning range with shot response time.
文摘Optical methods such as Twyman-Green interferometry, moiré interferometry, holographic interferometry and speckle interferometry are useful to measure displacement and strain in the full-field of structures. Recently phase analysis method of fringe patterns obtained by these optical methods becomes popular, and it provides accurate quantitative results in the full-field. In this paper, in order to measure displacement and strain, real-time or high-speed nano-meter displacement measurement methods developed by the authors are introduced. That is, (1) out-of-plane displacement analysis by Twyman-Green interferometry using integrated phase-shifting method using Fourier transform phase-shifting method, (2) simultaneous two-dimensional in-plane displacement analysis by moiré interferometry and (3) out-of-plane displacement analysis by phase-shifting digital holographic interferometry. The theories and applications are shown.
