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Izumisano, Japan

Fujigaki M.,Wakayama University | Nishitani R.,Wakayama University | Morimoto Y.,Moire Institute Inc.
EPJ Web of Conferences | Year: 2010

Phase-shifting digital holography is a convenient method to measure displacement and strain distributions. Development of compact and conventional strain distribution measurement equipment for practical use is required for inspection of health monitoring and life lengthening of infrastructures such as steel bridges. In this paper, we propose an off-axis reconstruction method for displacement and strain distribution measurement with a phase-shifting digital holography. In the case of off-axis optical setup, the pitch of the fringe appearing on the image sensor becomes smaller than a pixel size. However, the phase-shifting digital hologram can be obtained even if the off-axis setup and effective results can be obtained using a Windowed-PSDHI. The principle and the experimental result of strain distribution measurement was performed with this method using two cameras. © 2010 Owned by the authors, published by EDP Sciences. Source


Morimoto Y.,Moire Institute Inc. | Fujigaki M.,Wakayama University | Masaya A.,Wakayama University | Shimo K.,Wakayama University | And 2 more authors.
SAE International Journal of Materials and Manufacturing | Year: 2011

Recently, sampling moire method was developed to analyze the phase of a one-dimensional or two-dimensional grating on an object with high accuracy. In the method, several phase-shifted moire patterns are generated from one image of the grating. In order to analyze a shape by a stereoscopic method, it is necessary to find the corresponding points between the two images of the object recorded from different two cameras. It is possible to analyze the phase of the grating using the sampling moiré method and find the corresponding points as points with the same phase. It is also possible to analyze the displacement and strain from the corresponding point before and after deformation. This method is, therefore, suitable for shape and strain distribution measurement of a moving object. In this paper, a dynamic shape and strain measurement method using the sampling moiré method is proposed and a system for the measurement is developed. The principle of the method, the measurement system, and the experimental results applied to a rotating tire running at the speed of 80 km/h are shown. © 2011 SAE International. Source


Koganeya K.,Shima Seiki Manufacturing Ltd | Fujigaki M.,Wakayama University | Morimoto Y.,Moire Institute Inc.
Sen'i Gakkaishi | Year: 2011

It is well known that the faults such as thin-thick, neps and unevenness in the staple yarn make bad the quality of the fabric that is knitted from the yarn. There is a double ply yarn that have neither thin-thick nor neps and no specific cycle in yarn evenness that cause problem in the plain stitch fabric made from flat knitting machine. For comparison, the yarn which has almost same properties on evenness test as the former yarn and makes no problem fabric is selected. In the case of former yarn, the range of the tension which passes through needles on friction test is wider than that of latter yarn and the tension has a certain cyclic variation. The yarn which has certain cyclic tension variation at passing through the needles is made experimentally and is knitted. These results were shown. Source


Masaya A.,Wakayama University | Fujigaki M.,Wakayama University | Morimoto Y.,Moire Institute Inc.
AIP Conference Proceedings | Year: 2010

In this study, a system using a Field Programmable Gate Array (FPGA) memory board is proposed to obtain the full-size shape without any reduction of the image in real-time. The memory of the FPGA memory board has a phase analysis table and phase-coordinate tables. The brightness data of the recorded grating are stored in the phase analysis table to obtain the phase of the recorded grating. The calibration data using a moving reference plane are stored as a phase-coordinate table to obtain the coordinates of the phase. An experiment to evaluate this system was performed. The analysis speed of shape measurement using the memory board did not depend on a speed of a personal computer. The accuracy of shape measurement using the memory board and using software was almost the same. The analysis speed using the memory board was faster than the one using software. © 2010 American institute of Physics. Source


Shimo K.,Wakayama University | Fujigaki M.,Wakayama University | Masaya A.,Wakayama University | Morimoto Y.,Moire Institute Inc.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

Shape measurement and strain distribution measurement are important to analyze the behavior of a moving object. In this paper, a dynamic shape and strain measurement system by the sampling moire method is developed. Recently, phase analysis method using phase-shifting moire patterns generated in a computer from a grating image is proposed. This method is very suitable for dynamic measurement because the phase can be obtained from a one-dimensional or two-dimensional (2-D) grating image with high accuracy. It is possible to analyze strain distribution and shape measurement of a moving object using a grating pattern attached on the specimen surface. A dynamic shape and strain measurement system by the sampling moire method is developed. The principle and experimental results applied to a rotating object are shown. © 2010 SPIE. Source

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