Development of a vision based deflection measurement system and its accuracy assessment

Sładek, Jerzy; Ostrowska, Ksenia; Kohut, Piotr; Holak, Krzysztof; Gąska, Adam; Uhl, Tadeusz

doi:10.1016/j.measurement.2012.10.021

Cited by 70 publications

(50 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Care must be taken that different scale factors are applied to different axes to measure the 2D displacement. This simple method can also be used with cameras having apparent lens distortion, since the lens distortion correction method previously described can be used [15,57].…”

Section: Remarksmentioning

confidence: 99%

“…The default resolution is at pixel level, so interpolation schemes [8] are used to refine the result to the subpixel level. The feasible interpolation methods include bi-cubic interpolation [56], second-order polynomial interpolation [57] in spatial domain and zero-padding interpolation in frequency domain [8]. If the selected target includes robust and identifiable features, Harris corner detection that identifies the edge intersection points through a score value related to the eigenvalues of image gradient matrix could be an alternative to refine the initial matching location [24].…”

Section: Target Trackingmentioning

confidence: 99%

See 1 more Smart Citation

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

Brownjohn

2017

J Civil Struct Health Monit

252

125

View full text Add to dashboard Cite

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.

show abstract

Section: Remarksmentioning

confidence: 99%

Section: Target Trackingmentioning

confidence: 99%

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

Brownjohn

2017

J Civil Struct Health Monit

252

125

View full text Add to dashboard Cite

show abstract

“…Therefore, when a DIL is measured, the general diagram of moment m(ξ) of the continuous beam can constructed by substituting the resultant R i from Equation (21) in Equation (16). …”

Section: Statically Indeterminate Systemsmentioning

confidence: 99%

“…This moment is substituted into Equation (21). The resultant R 1 is then substituted into Equation (16) and the general function of moment m(ξ) in this two-span continuous beam is constructed. Using this procedure, the diagram of moment m(ξ) is plotted in Figure 6d.…”

Section: Using Deflection Influence Line (Dil)mentioning

confidence: 99%

Framework for Flexural Rigidity Estimation in Euler-Bernoulli Beams Using Deformation Influence Lines

Zeinali

Story

2017

Infrastructures

View full text Add to dashboard Cite

Structural degradation is an inevitable part of a structure's service life. Detecting structural impairments and assessing their nature is a significant challenge. Degradations reduce structural system stiffness and subsequently affect system deformations. An appropriate structural health index that is able to capture these changes in deformation and relate them to a structural system stiffness may help engineers to adequately rate structural condition. This paper outlines a theoretical framework for the utilization of static deformation influence lines for estimating the flexural rigidity of Euler-Bernoulli beams. In the proposed technique, the relationship between the second derivative of the deformation influence line and the flexural rigidity for both statically determinate and indeterminate beam structures is presented. The proposed method provides a flexural rigidity estimate (FRE) over the entire span that is based on a single measurement location and estimates both the location and severity of impairments, regardless of the location of the measurement or the damaged zones. Noisy analytical simulations are presented with noise levels of 0%, 0.5%, 1%, 2%, 3%, and 4%; in all cases the modeled damage is quantified and localized using the FRE. A laboratory experiment is also presented that validates the theoretical framework.

show abstract

“…Recently, vision-based techniques were successfully used to measure various structures and get satisfactory results. [15][16][17][18][19][20][21][22][23][24] Quan et al 25 achieved three-dimensional displacement measurement based on two-dimensional (2-D) digital image correlation (DIC). Kim et al 26 proposed a vision-based monitoring system that uses DIC to evaluate the cable tensile force of a cable-stayed bridge.…”

Section: Introductionmentioning

confidence: 99%

Vision-based displacement measurement sensor using modified Taylor approximation approach

et al. 2016

View full text Add to dashboard Cite

, "Vision-based displacement measurement sensor using modified Taylor approximation approach," Opt. Eng. 55 (11) Abstract. The development of image sensors and optics lenses has contributed to the rapidly increasing use of vision-based methods as noncontact measurement methods in many areas. A high-speed camera system is developed to realize the displacement measurement in real time. Conventional visual measurement algorithms are commonly subjected to various shortcomings, such as complex processes, multiparameter adjustments, or integer-pixel accuracy. Inspired from the combination of block-matching algorithm and simplified optical flow, a motion estimation algorithm that uses modified Taylor approximation is proposed and applied to the vision sensor system. Simplifying integer-pixel searching with a rounding-iterative operation enables the modified algorithm to rapidly accomplish one displacement extraction within 1 ms and yield satisfactory subpixel accuracy. The performance of the vision sensor is evaluated through a simulation test and two experiments on a grating ruler motion platform and a steering wheel system of a forklift. Experimental results show that the developed vision sensor can extract accurate displacement signals and accomplish the vibration measurement of engineering structures.

show abstract

Development of a vision based deflection measurement system and its accuracy assessment

Cited by 70 publications

References 31 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

Framework for Flexural Rigidity Estimation in Euler-Bernoulli Beams Using Deformation Influence Lines

Vision-based displacement measurement sensor using modified Taylor approximation approach

Contact Info

Product

Resources

About