Displacement and Strain Distribution Measurement by Sampling Moire Method

Morimoto, Yoshiharu; Fujigaki, Motoharu; Masaya, Akihiro

doi:10.3131/jvsj2.54.32

Cited by 12 publications

(4 citation statements)

References 14 publications

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“…The grating projection method uses a grating to measure the shape (for examples, [ 1 , 2 , 3 , 4 , 5 , 6 ]), and the sampling moiré method uses a grating to measure deformation [ 21 , 22 ]. The position of the grating is accurately obtained using image processing.…”

Section: Principle Of the Oppa Methodsmentioning

confidence: 99%

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High-Speed Measurement of Shape and Vibration: Whole-Field Systems for Motion Capture and Vibration Modal Analysis by OPPA Method

Morimoto

2020

Sensors

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In shape measurement systems using a grating projection method, the phase analysis of a projected grating provides accurate results. The most popular phase analysis method is the phase shifting method, which requires several images for one shape analysis. Therefore, the object must not move during the measurement. The authors previously proposed a new accurate and high-speed shape measurement method, i.e., the one-pitch phase analysis (OPPA) method, which can determine the phase at every point of a single image of an object with a grating projected onto it. In the OPPA optical system, regardless of the distance of the object from the camera, the one-pitch length (number of pixels) on the imaging surface of the camera sensor is always constant. Therefore, brightness data for one pitch at any point of the image can be easily analyzed to determine phase distribution, or shape. This technology will apply to the measurement of objects in motion, including automobiles, robot arms, products on a conveyor belt, and vibrating objects. This paper describes the principle of the OPPA method and example applications for real-time human motion capture and modal analysis of free vibration of a flat cantilever plate after hammering. The results show the usefulness of the OPPA method.

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Section: Principle Of the Oppa Methodsmentioning

confidence: 99%

“…There are various phase analysis methods (for example, [ 1 , 11 , 21 , 22 , 23 , 24 , 25 ]). The author also developed the OPPA method [ 9 , 16 , 17 , 18 ].…”

Section: Principle Of the Oppa Methodsmentioning

confidence: 99%

High-Speed Measurement of Shape and Vibration: Whole-Field Systems for Motion Capture and Vibration Modal Analysis by OPPA Method

Morimoto

2020

Sensors

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“…However, we confirmed that detection was difficult, when these methods are used for verifying a deformation in flat parts. Image processing methods by using the surface normal direction information was proposed to detect a deformation in flat parts (Hirose et al, 2000;Morimoto et al, 2011;Tanaka et al, 1994). However, most of these methods use a fixed parameter, such as block size.…”

Section: Background Of This Researchmentioning

confidence: 99%

Development of Defect Verification System of IC Lead Frame Surface using a Ring-lighting

Nakamura¹,

Enokida

2016

Proceedings of the 11th Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications

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It is especially needed for the IC lead frames used in the manufacture of semiconductors, which require both high quality and miniaturization. To overcome above, automatic defect detection systems based on image processing methods were proposed. Especially, this paper focuses on methods using the surface normal direction to detect a deformation in flat parts. Since most of these methods use a fixed parameter, the risk of missing a defect in industrial parts becomes a problem. In this paper, new defect detection method is proposed for detecting various defect sizes and defect types. This method determines the appropriate block size based on the median value of luminance dispersions calculated for several block sizes and learning from a sample that detects a defect point beforehand. We used 105 samples in our experiments. Our experimental results show our proposed method selects the superior parameters and identification of the defect area selected is superior with learning in detecting defects of several sizes.

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“…Vibration detection using video image processing has been rigorously studied in recent years. [3][4][5] Imai et al 3 successfully detected the deflections of a highway overpass due to passing vehicles on it by applying a digital image correlation method to video images taken from directly under the bridge. Tsuda et al 4 used the sampling moiré method to detect the deflections of bridges.…”

Section: Introductionmentioning

confidence: 99%

Measurement of micro-vibration frequency along optical axis using spatial frequency analysis of video images

Okamura

Osa

Miura

2023

International Workshop on Advanced Imaging Technology (IWAIT) 2023

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This study proposes a method for detecting micro-vibrations along the optical axis of a target object using video image analysis. The proposed method detects vibrations as time variances in the scaling factor of the object by checking the shift in the peaks in the spatial power spectrum of the images. We conducted an experiment wherein a checkerboard placed 2 m below the video camera was vibrated using an actuator. The results show that the proposed method could measure the vibration frequency even when the amplitude is 0.25 permille of the shooting distance.

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Displacement and Strain Distribution Measurement by Sampling Moire Method

Cited by 12 publications

References 14 publications

High-Speed Measurement of Shape and Vibration: Whole-Field Systems for Motion Capture and Vibration Modal Analysis by OPPA Method

High-Speed Measurement of Shape and Vibration: Whole-Field Systems for Motion Capture and Vibration Modal Analysis by OPPA Method

Development of Defect Verification System of IC Lead Frame Surface using a Ring-lighting

Measurement of micro-vibration frequency along optical axis using spatial frequency analysis of video images

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