Three dimensional profile measuring method based on coupled Dammann gratings

2015 ◽  
Author(s):  
Shaoqing Wang ◽  
Changhe Zhou ◽  
Shengbin Wei ◽  
Kun Liu ◽  
Xin Fan
Keyword(s):  
Three Dimensional ◽  
Measuring Method

Development of a Visual Monitoring System for Deformation Measuring of Welded Members and its Application

2008 ◽  
Vol 580-582 ◽  
pp. 557-560 ◽  
Author(s):  
J.G. Han ◽  
Kyong Ho Chang ◽  
Gab Chul Jang ◽  
K.K. Hong ◽  
Sam Deok Cho ◽  
...  
Keyword(s):  
Monitoring System ◽  
Three Dimensional ◽  
Measuring Method ◽  
Welding Residual Stress ◽  
Measuring System ◽  
Visual Monitoring ◽  
Test Error ◽  
Steel Members ◽  
Loading Tests ◽  
Visual Monitoring System

Recently, in the loading tests for steel members, the deformation value is measured by calculating a distance of both cross-heads. This measuring method encounters a test error due to various environmental factors, such as initial slip, etc.. Especially, in the case of welded members, the non-uniform deformation behavior in welded joints is observed because of the effect of welding residual stress and weld metal. This is mainly responsible for a test error and a loss of the reliability for used test instruments. Therefore, to improve the accuracy and the applicability of measuring system, it is necessary to employ a visual monitoring system which can accurately measure the local and overall deformation of welded members. In this paper, to accurately measure a deformation of welded members, a visual monitoring system (VMS) was developed by using three-dimensional digital photogrammetry. The VMS was applied to the loading tests of a welded member. The accuracy and the applicability of VMS was verified by comparing to the deformation value measured by a test instrument (MTS-810). The characteristics of the behavior near a welded joint were investigated by using VMS.

scholarly journals A Three-dimensional Finger Motion Measurement System of a Thumb and an Index Finger Without a Calibration Process

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 756 ◽  
Author(s):  
Yeongyu Park ◽  
Joonbum Bae
Keyword(s):  
Index Finger ◽  
Three Dimensional ◽  
Length Change ◽  
Measuring Method ◽  
Finger Joint ◽  
Joint Angles ◽  
Calibration Process ◽  
Hand Motion ◽  
Wearable Systems ◽  
Cmc Joint

Various wearable systems have been investigated to measure hand motion, but some challenges remain. Many systems require a calibration process to map sensor signals to actual finger joint angles by the principle of measuring the length change of the finger, or bending sensors. Also, few studies have investigated how to measure thumb motion accurately using the wearable systems. This paper proposes an exoskeleton system with linear Hall sensors to measure three-dimensional hand motion without a calibration process. The calibration process is avoided by measuring finger joint angles through an absolute rotation measurement. A new wearing method with lower parts underneath the hand joints and rubber bands is proposed to fix the structure to the hand and adapt it for various hand sizes. As the thumb has a complex biomechanical feature at carpometacarpal (CMC) joint, a new measuring method of the CMC joint is proposed to directly calculate the orientation of the metacarpal. The prototype of the thumb and index finger was manufactured, and the performance was verified experimentally by using an optical motion capture system.

A single CCD measuring method for three-dimensional rectangular objects

2012 ◽  
Author(s):  
To-Wen Lai ◽  
I-Hsum Li ◽  
Cheng-Pei Tsai ◽  
Wei-Yen Wang ◽  
Ming-Chih Lu
Keyword(s):  
Three Dimensional ◽  
Measuring Method

Functional Anthropometry: The CC Method and its Application

1976 ◽  
Vol 20 (16) ◽  
pp. 368-373
Author(s):  
Wolfgang Lange
Keyword(s):  
Three Dimensional ◽  
Measuring Method ◽  
Cartesian Coordinates ◽  
Actual Working ◽  
Working Postures ◽  
Hands And Feet ◽  
Head Positions

Using Cartesian Coordinates a method was developed to determine the location of a point in space. This method allows the recording of three-dimensional relationships among anthropometric landmarks. The method facilitates the assessment of changes anthropometric dimensions brought about by actual working postures. “CC data” were recorded describing head positions and eye locations when subjects (n = 60) assumed various head postures while maintaining fixation of trunk, hands and feet. The results indicate the usefulness of the CC Measuring Method.

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