Nontarget Image-Based Technique for Small Cable Vibration Measurement

Ji, Yao; Chang, Chin-Chen

doi:10.1061/(asce)1084-0702(2008)13:1(34)

Cited by 131 publications

(58 citation statements)

References 8 publications

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“…3.2.3.2 Application review LK optical flow estimation was applied in a laboratory test of a multi-storey metal tower [15] for system identification, and for field application in deformation measurement in a footbridge [59] and bridge stay-cable vibration measurement [85,86].…”

Section: Principlementioning

confidence: 99%

“…If the structural motion along edges is one-dimensional translation with known direction, e.g. bridge stay cable vibration [85], optical flow estimation is viable.…”

Section: Remarksmentioning

confidence: 99%

“…accelerometers [40,85,106], velocimeters [41] and load cells [105]. Vision-based systems require no access to cables [16,30,40,85,86,90,105,106] and are capable of measuring the vibrations of multiple cables using a single camera [16,86,105,106] that is comparable to an array of accelerometers.…”

Section: Application Examplesmentioning

confidence: 99%

See 2 more Smart Citations

Review of machine-vision based methodologies for displacement measurement in civil structures

Brownjohn

2017

J Civil Struct Health Monit

254

125

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Vision-based systems are promising tools for displacement measurement in civil structures, possessing advantages over traditional displacement sensors in instrumentation cost, installation efforts and measurement capacity in terms of frequency range and spatial resolution. Approximately one hundred papers to date have appeared on this subject, investigating topics like system development and improvement, the viability on field applications and the potential for structural condition assessment. The main contribution of this paper is to present a literature review of vision-based displacement measurement, from the perspectives of methodologies and applications. Video-processing procedures in this paper are summarised as a three-component framework: camera calibration, target tracking and structural displacement calculation. Methods for each component are presented in principle, with discussions about the relative advantages and limitations. Applications in the two most active fields, bridge deformation and cable vibration measurement, are examined followed by a summary of field challenges observed in monitoring tests. Important gaps requiring further investigation are presented, e.g. robust tracking methods, non-contact sensing and measurement accuracy evaluation in field conditions.

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Section: Principlementioning

confidence: 99%

“…If the structural motion along edges is one-dimensional translation with known direction, e.g. bridge stay cable vibration [85], optical flow estimation is viable.…”

Section: Remarksmentioning

confidence: 99%

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Review of machine-vision based methodologies for displacement measurement in civil structures

Brownjohn

2017

J Civil Struct Health Monit

254

125

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show abstract

“…To our knowledge, only a few attempts have been made to apply visionbased methods for cable force estimation. For example, Ji and Chang [15] used a nontarget image-based technique for cable vibration measurement. An optical flow method was adopted to estimate displacement of an arbitrarily chosen ROI on the image plane.…”

Section: Introductionmentioning

confidence: 99%

Experimental Verification for Cable Force Estimation Using Handheld Shooting of Smartphones

Zhao¹,

Ri²,

Wang³

2017

Journal of Sensors

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Currently, due to the rapid development and popularization of smartphones, the usage of ubiquitous smartphones has attracted growing interest in the field of structural health monitoring (SHM). The portable and rapid cable force measurement for cablesupported structures, such as a cable-stayed bridge and a suspension bridge, has an important and practical significance in the evaluation of initial damage and the recovery of transportation networks. The extraction of dynamic characteristics (natural frequencies) of cable is considered as an essential issue in the cable force estimation. Therefore, in this study, a vision-based approach is proposed for identifying the natural frequencies of cable using handheld shooting of smartphone camera. The boundary of cable is selected as a target to be tracked in the region of interest (ROI) of video image sequence captured by smartphone camera, and the dynamic characteristics of cable are identified according to its dynamic displacement responses in frequency domain. The moving average is adopted to eliminate the noise associated with the shaking of smartphone camera during measurement. A laboratory scale cable model test and a pedestrian cable-stayed bridge test are carried out to evaluate the proposed approach. The results demonstrate the feasibility of using smartphone camera for cable force estimation.

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“…Using a commercial digital camcorder with a sampling rate of 30 fps, Shih et al [19] applied the digital image correlation (DIC) technique to obtain the dynamic displacements of three targets attached on the concrete surface of a bridge under the train load. Ji and Chang [20] employed the optical flow method to develop a nontarget image-based technique for measuring the cable vibration of a small pedestrian bridge with a single camcorder. A measurement accuracy of 0.1-0.4 mm was attained in this study under the vibration amplitude of 20 mm.…”

Section: Introductionmentioning

confidence: 99%

Application of digital photogrammetry techniques in identifying the mode shape ratios of stay cables with multiple camcorders

Chen

Tseng

et al. 2015

Measurement

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Nontarget Image-Based Technique for Small Cable Vibration Measurement

Cited by 131 publications

References 8 publications

Review of machine-vision based methodologies for displacement measurement in civil structures

Review of machine-vision based methodologies for displacement measurement in civil structures

Experimental Verification for Cable Force Estimation Using Handheld Shooting of Smartphones

Application of digital photogrammetry techniques in identifying the mode shape ratios of stay cables with multiple camcorders

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