Phase-shifting projection moire for out-of-plane displacement measurement

2001 ◽  
Author(s):  
Moon-sik Jeong ◽  
Seung-Woo Kim
Keyword(s):  
Displacement Measurement ◽  
Phase Shifting ◽  
Out Of Plane ◽  
Plane Displacement ◽  
Projection Moire

Out-of-plane Displacement Measurement Using Phase-shifting Digital Holography

2003 ◽  
Vol 2003.9 (0) ◽  
pp. 175-176
Author(s):  
Isao TAKAHASHI ◽  
Yoshiharu MORIMOTO ◽  
Takanori NOMURA ◽  
Satoru YONEYAMA ◽  
Motoharu FUJIGAKI
Keyword(s):  
Digital Holography ◽  
Displacement Measurement ◽  
Phase Shifting ◽  
Out Of Plane ◽  
Plane Displacement

Stroboscopic Fringe Projection Method for 3D Dynamic Displacement Measurement

2011 ◽  
Vol 70 ◽  
pp. 255-260
Author(s):  
Xiao Yuan He ◽  
Fei Peng Zhu ◽  
Cheng Fei Wang ◽  
Ying Jun Xu
Keyword(s):  
Displacement Measurement ◽  
Phase Shifting ◽  
Image Correlation ◽  
Surface Pattern ◽  
Fringe Projection ◽  
Vibration Period ◽  
Dynamic Displacement ◽  
Out Of Plane ◽  
Fringe Patterns ◽  
Plane Displacement

The determination of dynamic characteristics of microelectromechanical system (MEMS) devices is of great importance. Currently, vibrometer techniques using a Laser-Doppler Vibrometer (LDV) are used for dynamic measurement of MEMS, utilizing an interferometer based on a stroboscope and high-speed cine photomicrography are used for MEMS. But, these methods can’t be used for 3D dynamic displacement measurement simultaneously because of their limitations. In this paper, an optical system for 3D dynamic displacement measurement of micro-components is presented using stroboscopic fringe projection and digital image correlation (DIC), which can measure both in-plane and out-of-plane motions simultaneously. In the system, stroboscopic fringe patterns are projected onto the surface of a vibrating specimen by a phase-shifting projector and stroboscopic illumination supplied with a pulsed laser diode. Synchronization between the stroboscopic laser and the driving signal for the specimen vibrating is achieved by the stroboscopic controller. For a certain vibration state, four deformed phase-shifting fringe patterns are captured by a high-resolution CMOS camera with a long working distance microscope. The images are processed by a phase-shifting technique to obtain the phase distribution. The surface pattern of the specimen without fringes could be obtained by certain phase-shifting algorithms. When stroboscopic pulses are delayed, the stroboscopic phase is changed and another vibrating status could be captured in the same way. Comparing the phase distributions of these two states, the out-of-plane displacement is achieved, which is the displacement of the specimen between these two states. The in-plane displacement could be obtained from the surface pattern without fringes by DIC. Adjusting the phase delay of illumination by stroboscopic controller, the motions of the specimen in the whole vibration period can be obtained.

A simple projection moiré system to measure displacements of aircraft structures

2007 ◽  
Vol 42 (6) ◽  
pp. 477-495 ◽  
Author(s):  
U Galietti ◽  
K Genovese ◽  
L Lamberti ◽  
D Posa
Keyword(s):  
Analytical Model ◽  
Large Scale ◽  
Industrial Applications ◽  
Processing Method ◽  
Simple Analytical Model ◽  
Aerodynamic Loads ◽  
Out Of Plane ◽  
Plane Displacement ◽  
Good Agreement ◽  
Projection Moire

This work presents a simple projection moiré system (PMS) to measure displacements of large-scale aeronautical components. The system includes standard optics, uses a standard fringe-processing method, and relies on a simple analytical model to recover topographic information. An extensive calibration campaign, based on design of experiments, is conducted in order to find the best analytical model for retrieving the out-of-plane displacement field from the moiré pattern and to find the optimal combination of parameters involved in the measurement system. In order to check the suitability of the present PMS device for practical industrial applications, distortions induced by aerodynamic loads on a landing-light glazing of an Airbus A340 are measured. Experimental results are in good agreement with other measurements carried out independently.

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