Non-contact Full Field Vibration Measurement Based on Phase-Shifting

Kayaba, Hiroyuki; Kokumai, Yuji

doi:10.1109/cvpr.2017.273

Cited by 6 publications

(6 citation statements)

References 23 publications

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“…We also employ signal analysis in the Fourier domain, however rather than magnifying the subtle motion or estimating material properties, we estimate the frequency of the subtle tremor motion. The works in [14,15] use specialized sensors or a digital light-processing projector, and a high frame-rate camera to detect small vibrations. Unlike [14,15], we do not employ specific cameras or expensive sensors, we estimate the tremor frequency from common RGB videos.…”

Section: Motion Analysismentioning

confidence: 99%

“…The works in [14,15] use specialized sensors or a digital light-processing projector, and a high frame-rate camera to detect small vibrations. Unlike [14,15], we do not employ specific cameras or expensive sensors, we estimate the tremor frequency from common RGB videos.…”

Section: Motion Analysismentioning

confidence: 99%

“…In the context of tremor analysis, existing approaches require the use of specialized sensors [6,8,14,15], which makes it difficult to apply these methods in practice. Moreover, the targeted application of these approaches are the more high-level tremor diagnosing problem [14,26] or tremor/no-tremor classification [28].…”

Section: Introductionmentioning

confidence: 99%

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Hand-Tremor Frequency Estimation in Videos

Pintea

Zheng

et al. 2019

Lecture Notes in Computer Science

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We focus on the problem of estimating human hand-tremor frequency from input RGB video data. Estimating tremors from video is important for non-invasive monitoring, analyzing and diagnosing patients suffering from motor-disorders such as Parkinson's disease. We consider two approaches for hand-tremor frequency estimation: (a) a Lagrangian approach where we detect the hand at every frame in the video, and estimate the tremor frequency along the trajectory; and (b) an Eulerian approach where we first localize the hand, we subsequently remove the large motion along the movement trajectory of the hand, and we use the video information over time encoded as intensity values or phase information to estimate the tremor frequency. We estimate hand tremors on a new human tremor dataset, TIM-Tremor, containing static tasks as well as a multitude of more dynamic tasks, involving larger motion of the hands. The dataset has 55 tremor patient recordings together with: associated ground truth accelerometer data from the most affected hand, RGB video data, and aligned depth data.

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Section: Motion Analysismentioning

confidence: 99%

Section: Motion Analysismentioning

confidence: 99%

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Hand-Tremor Frequency Estimation in Videos

Pintea

Zheng

et al. 2019

Lecture Notes in Computer Science

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“…In most cases, multiple measurements of different types of phantom models are performed. The models include flat surfaces, spheres, random and complex objects, and human body parts [10]- [16], [24]- [29]. Prior to the quality analysis, the acquired 3D image is often registered to the model.…”

Section: Discussionmentioning

confidence: 99%

Method for Parametric Evaluation of 3-D Surface Imaging Systems for Applications With Moving Objects

Kaiser,

Brusa,

Fiechter

et al. 2024

IEEE Trans. Instrum. Meas.

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Medical applications in which patient movements are tracked with 3D surface imaging systems are becoming increasingly popular. The 3D imaging systems used for such applications must be able to cope with controlled and uncontrolled motions of the human body. The key factors for producing a highquality 3D representation of the moving human body are the spatial resolution, accuracy, and precision of the 3D imaging system. To our knowledge, no international standard yet exists to assess these parameters. In this paper, we propose a phantom model, a method, and parameters for the assessment of spatial resolution, accuracy, and precision to evaluate systems for the 3D imaging of moving objects. The proposed phantom model is an extension of the standard 1951 USAF resolution test chart to 3D and consists of two parallel staircases with varying step heights. The phantom model is actuated with an industrial robot. The application of our method to the Photoneo MotionCam-3D showed that their multishot structured-light mode has a higher accuracy for static and slowly moving objects (accuracy of 0.1 mm) than their single-shot structured-light mode (accuracy of 0.5 mm). However, the single-shot mode can capture fast-moving objects without much loss of accuracy and precision. This provides practical quantifications for the Photoneo MotionCam-3D. Furthermore, this confirms that the proposed phantom model, method, and parameters can be used as part of a standard to assess the spatial resolution, accuracy, and precision of systems for the 3D imaging of moving objects.

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“…However, this contact-type measurement approach has the deficiencies of mass loading effect, it is particularly problematic for thin-walled parts, low spatial sensing resolution, costly, time and labour-consuming installation, and so on. Therefore, significant interest has been shown in the development of non-contacting vibration measurement techniques [7] .…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Measurement of Multipoint Mechanical Vibration For Thin-Walled Parts Using Monocular Machine Vision Optical Flow Tracking

Shao

2021

Preprint

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Thin-walled parts (TWPs) have been widely employed in various industry fields and put forward a specific requirement of simultaneous multipoint vibration measurement for their dynamic behaviours understanding. The development of machine vision theory and technology enable the machine vision-based technique to measure the vibration of mechanical equipment. Lucas-Kanade based template tracking (LKBTT) can provide a robust, longer term motion estimation of the interesting object, but lacks spatial resolution and also deeper use of contextual cues. Lucas-Kanade based optical ﬂow tracking (LKBOPT) is usually used for frame-by-frame feature-level motion estimation, and has the potential to satisfy the vibration measurement requirements of TWPs. LKBOPT has not been introduced to vibration measurement yet, and also had the challenge of long-term motion estimation. In order to satisfy the simultaneous multipoint vibration measurement requirements of TWPs, a coarse-to-fine tracking method is developed by introducing LKBOPT to vibration measurement and combining it with LKBTT. A region of interest detection algorithm is investigated to acquire the tracking template according to the measurable object. LKBTT is introduced to realize the coarse tracking and obtain the vibration information of the tracking template. An improved LKBOPT is investigated to realize the fine tracking and acquire the vibration information of multipoint inside the tracking template simultaneously. Finally, the simultaneous measurement system of multipoint mechanical vibration for TWPs is utilized with a high-speed camera system based on both Python and open source computer vision (OpenCV) libraries. The vibration measurement performance of the proposed method has been experimentally verified with two experiments under laboratory conditions by comparing the results with those using accelerometers. The experiment has shown that the proposed method is effective in the remote simultaneous multipoint vibration measurement of TWPs with satisfactory accuracy and efficiency.

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Non-contact Full Field Vibration Measurement Based on Phase-Shifting

Cited by 6 publications

References 23 publications

Hand-Tremor Frequency Estimation in Videos

Hand-Tremor Frequency Estimation in Videos

Method for Parametric Evaluation of 3-D Surface Imaging Systems for Applications With Moving Objects

Simultaneous Measurement of Multipoint Mechanical Vibration For Thin-Walled Parts Using Monocular Machine Vision Optical Flow Tracking

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