Feasibility Study for Vision-Based Cable Force Measurement Using Smartphone

2016 ◽  
Author(s):  
Xuefeng Zhao ◽  
Kwang Ri ◽  
Yan Yu ◽  
Chunil Kang ◽  
Mingchu Li ◽  
...  
Keyword(s):  
Measurement Method ◽  
Force Measurement ◽  
Smartphone Application ◽  
Cable Model ◽  
Construction Period ◽  
Service Period ◽  
Cable Force ◽  
Vibration Responses ◽  
Cable Force Measurement ◽  
Circular Target

An accurate cable force measurement is one of very important practical problems during construction period as well as during service period of cable stayed bridge. In the recent years, with the advances in smartphone technologies, it is possible to rapidly evaluate structural health status and postevent damage using ubiquitous smartphones. In this paper, a novel vision-based cable force measurement method using smartphone camera is proposed for the first time, which enable to estimate cable force by recognizing cable vibration using smartphone camera, and then cable model test is carried out to verify the feasibility of the proposed method. The comparison test between the smartphone application Orion-CC measuring cable force from smartphone built-in accelerometer and the proposed method is conducted on a laboratory scale cable model with different sampling rates. In the proposed method, the vibration responses of cable are obtained by monitoring displacements of a preprinted black circular target attached on the cable model using smartphone camera. The test results showed satisfactory agreements between two methods in both frequency domain and cable force value, demonstrating the feasibility of the proposed cable force measurement method and its advantages such as convenience, ease of operation, and speediness.

Portable and convenient cable force measurement using smartphone

2015 ◽  
Vol 5 (4) ◽  
pp. 481-491 ◽  
Author(s):  
Xuefeng Zhao ◽  
Ruicong Han ◽  
Yanbing Ding ◽  
Yan Yu ◽  
Quanhua Guan ◽  
...  
Keyword(s):  
Force Measurement ◽  
Cable Force ◽  
Cable Force Measurement

The Research on Cable Force Measurement Based on Degenerated Element with Frequency Method

2013 ◽  
Vol 405-408 ◽  
pp. 1709-1715
Author(s):  
Xin Cui ◽  
Yong Jiang ◽  
Li Wen Fu ◽  
Jin Feng Wang
Keyword(s):  
Numerical Method ◽  
Theoretical Basis ◽  
Force Measurement ◽  
Beam Element ◽  
Testing System ◽  
Frequency Method ◽  
Operation Procedure ◽  
Cable Force ◽  
Cable Force Measurement ◽  
The Given

At present, among the methods of cable force measurement, the frequency method is applied extensively for its mature theory and rapid and repeated operation procedure. Based on the theory of frequency method measurement, it generally uses the numerical method with beam element to analysis the parameters of cables under the given conditions. However, the conventional beam element is not able to simulate the bending stiffness in beams section. Therefore, it turns to degenerated beam element to simulate cables and the results agree well with the results based on beam element and formulas calculation, and it provides theoretical basis for the later cable force testing system.

Smartphone-Based Mobile Testing Technique for Quick Bridge Cable–Force Measurement

2017 ◽  
Vol 22 (4) ◽  
pp. 06016012 ◽  
Author(s):  
Xuefeng Zhao ◽  
Ruicong Han ◽  
Yan Yu ◽  
Weitong Hu ◽  
Dong Jiao ◽  
...  
Keyword(s):  
Force Measurement ◽  
Testing Technique ◽  
Mobile Testing ◽  
Cable Force ◽  
Bridge Cable ◽  
Cable Force Measurement

scholarly journals Research on Non-Contact and Non-Fixed Cable Force Measurement Based on Smartphone

2021 ◽  
Vol 11 (19) ◽  
pp. 8902
Author(s):  
Yongwei Wang ◽  
Kunyao Li ◽  
Yuan Chen ◽  
Shuyuan Xu ◽  
Wenchi Shou
Keyword(s):  
Force Measurement ◽  
Real Life ◽  
Operation Time ◽  
Maximum Error ◽  
Video Data ◽  
Stay Cable ◽  
Vibration Displacement ◽  
Cable Force ◽  
Cable Force Measurement ◽  
Cable Forces

Stay cable is the major load-carrying element in cable-stayed bridges. The process of monitoring cable forces would be beneficial to ensure the safety of bridges. The conventional sensor-based approaches to measure stay cable forces is complicated in operation, time-consuming and relatively expensive. In order to confront these disadvantages, a lightweight measurement method using smartphone imagery was proposed in this paper. The video data acquisition process was first standardized by using a pre-designed target. Then, a novel algorithm to extract the vibration displacement of stay cables under complex condition was developed. An automatic correction algorithm was provided to further improve the displacement results. On top of that, a smartphone-based software for determining cable forces was developed and tested on a real-life bridge. The results showed a maximum error of 1.99% compared with the cable force obtained by using a dynamic tester. The developed software is proven to be feasible in real-life projects and can achieve high accuracy in cable force determination. At the same time, the proposed method does not require a fixed camera for measurement and is not limited by personnel experience and measurement time, facilitating real-time monitoring of multiple projects, multiple cable surfaces and multiple personnel in a visual vibration environment.

scholarly journals Suspender Replacement Method for Long-Span Concrete-Filled Steel Tubular Arch Bridges and Cable Force Measurement Based on Frequency Method

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Yulin Deng ◽  
Luming Deng
Keyword(s):  
Force Measurement ◽  
Estimation Method ◽  
Traffic Load ◽  
Frequency Method ◽  
Arch Bridge ◽  
Calculated Length ◽  
Long Span ◽  
Replacement Method ◽  
Cable Force ◽  
Cable Force Measurement

The suspenders on the sides of an arch bridge are highly vulnerable to damage caused by traffic load and environmental corrosion. To accurately estimate the cable force of suspenders, herein, we analyse the influencing factors through a suspender tension test based on the principle of suspender vibration. The frequency of each suspender of the bridge is evaluated using the frequency method. By combining the cable force data measured directly and the measured suspender frequency, the formulas for calculating the cable forces of long and short suspenders are fitted, and a reasonable estimation method for the calculated length of short suspenders is provided. The formulas are verified through application to a CFST arch bridge. Results indicate that the proposed formula effectively considers the influence of the sleeve on the overall calculated length of the suspender. The formula calculates the suspender cable force with higher accuracy, proving its suitability for engineering use.

Cable Force Measurement Technology and Engineering Application

2021 ◽  
Vol 62 (3) ◽  
pp. 185-194
Author(s):  
Ju-wei Xia ◽  
Yun-long Yao ◽  
Xiao-shun Wu ◽  
Yuan-hong Chen
Keyword(s):  
Real Time ◽  
Structural Engineering ◽  
Force Measurement ◽  
Engineering Application ◽  
Force Balance ◽  
Measurement Technology ◽  
Practical Engineering ◽  
Cable Force ◽  
Force Monitoring ◽  
Cable Force Measurement

With the continuous development of prestressing technology, cables have been widely used in structural engineering. A special concern in practical engineering is selecting the appropriate cable force measurement technology. This paper analyzes and introduces the principle of cable force measurement technology commonly used in current engineering from three aspects, namely, strain, vibration and wave fluctuation, and force balance. Combined with an actual project, the selection and arrangement of measuring points in the cable pre-tension measurement and other issues are discussed. The engineering example shows that the cable force measurement method based on FBG sensor presented in this paper can capture the action of each construction tensioning operations in real time and accurately. Monitoring the tension of the structure in real time is convenient for engineers and technician. The process is suitable for cable force monitoring during the construction tensioning stage. Furthermore, the EM sensor has good stability and durability and is suitable for long-term cable force monitoring.

Ultrasonic measurement of clamping force for injection molding machine

2019 ◽  
Vol 39 (4) ◽  
pp. 388-396 ◽  
Author(s):  
Peng Zhao ◽  
Yao Zhao ◽  
Jianfeng Zhang ◽  
Junye Huang ◽  
Neng Xia ◽  
...  
Keyword(s):  
Injection Molding ◽  
Measurement Method ◽  
Large Scale ◽  
Force Measurement ◽  
Low Cost ◽  
Ultrasonic Method ◽  
Injection Molding Process ◽  
Propagation Time ◽  
Clamping Force ◽  
Molding Process

AbstractAn online and feasible clamping force measurement method is important in the injection molding process and equipment. Based on the sono-elasticity theory, anin situclamping force measurement method using ultrasonic technology is proposed in this paper. A mathematical model is established to describe the relationship between the ultrasonic propagation time, mold thickness, and clamping force. A series of experiments are performed to verify the proposed method. Experimental findings show that the measurement results of the proposed method agree well with those of the magnetic enclosed-type clamping force tester method, with difference squares less than 2 (MPa)2and errors bars less than 0.7 MPa. The ultrasonic method can be applied in molds of different thickness, injection molding machines of different clamping scales, and large-scale injection cycles. The proposed method offers advantages of being highly accurate, highly stable, simple, feasible, non-destructive, and low-cost, providing significant application prospects in the injection molding industry.

Vision-based force measurement using geometric moment invariants

2012 ◽  
Vol 226 (10) ◽  
pp. 2589-2601
Author(s):  
Wen Hu ◽  
Shigang Wang ◽  
Chun Hu ◽  
Hongtao Liu ◽  
Jinqiu Mo
Keyword(s):  
Measurement Method ◽  
Feature Vector ◽  
Force Measurement ◽  
Shape Descriptor ◽  
Support Vector ◽  
Moment Invariants ◽  
Geometric Moment ◽  
New Vision ◽  
Multi Class Classification ◽  
Standard Library

This article presents a new vision-based force measurement method to measure microassembly forces without directly computing the deformation. The shape descriptor of geometric moment invariants is used as a feature vector to describe the implicit relationship between an applied force and the deformation. Then, a standard library is established to map the corresponding relationship between the deformed cantilever under known forces and a set of feature vectors. Finally, a support vector machine compares the feature vector of deformed cantilever under an unknown force with those in the standard library, implements multi-class classification and predicts the unknown force. The vision-based force measurement method is validated for eight simulated microcantilevers of different sizes. Both regional and boundary moment invariants are used to constitute the feature vector. Simulated results show that the force measurement precision varies with length, width and height of cantilevers. If length increases and width and height decrease, the precision is higher. This trend can provide a reference for mechanism design of microcantilevers and microgrippers.

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