3-D Measurement and Reconstruction of Workpieces in Robotic Stereovision System

2015 ◽  
Vol 743 ◽  
pp. 783-786
Author(s):  
He Xi Li ◽  
J.J. Zhang
Keyword(s):  
Measurement Accuracy ◽  
Structural Parameters ◽  
Constraint Equation ◽  
Epipolar Line ◽  
Workpiece Surface ◽  
Reference Base ◽  
3 Dimensional ◽  
Intrinsic Parameters ◽  
Laser Stripe ◽  
Left And Right

An epipolar line constraint equation for robotic binocolar stereovision (BSV) is first established for the measurement and reconstruction of workpiece surface, in which the intrinsic parameters of two cameras and their extrinsic structural parameters with respect to a robotic reference base are included. To determine a sole matching point between left and right images, a laser emmiter is added to BSV to form a stripe on workpiece surface, experimental results show that the measurement accuracy of 3-dimensional (3-D) workpiece surface can be improved by combining epipolar line constraint with laser stripe projection, and the 3-D workpiece surface can be reconstructed with less errors.

Abstract TP436: Dysfunctional Cerebral Neovascularization And Remodeling Patterns In Obese And Lean Models Of Type 2 Diabetes

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Roshini Prakash ◽  
Maribeth Johnson ◽  
Susan C Fagan ◽  
Adviye Ergul
Keyword(s):  
Type 2 Diabetes ◽  
Glycemic Control ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Volume Density ◽  
3 Dimensional ◽  
Gk Rats ◽  
Dimensional Reconstruction ◽  
Branch Density

We previously reported intense pial cerebral collateralization and arteriogenesis in a mild and lean model of type 2 diabetes, Goto-Kakizaki (GK) rats. Further 3-dimensional fluroscein (FITC) imaging studies revealed regional differences in increased cerebral neovascularization which was associated with poor vessel wall maturity. Building upon these findings, the goals of this study were a) to compare and contrast this pathological neovascularization pattern in db/db mice and GK models of diabetes, and b) determine the effect of glycemic control on erratic cerebral neovascularization. Total vascular volume, density and surface area as well as structural parameters including microvessel/macrovessel ratio, non-FITC perfusing vessel abundance, penetrating arteriole (PA) branching density and diameter, and tortuosity were measured by 3 dimensional reconstruction of FITC stained vasculature using Z-stacked images obtained with confocal microscopy. Lean GK rats exhibited an increase in both micro and macrovessel density, non-perfusing vessel abundance, branch density, diameter and tortuosity. Glycemic control with metformin prevented these changes. Obese db/db mice, on the other hand, showed an increase in only microvascular density but this was not associated with an increase in non-FITC perfusing vessels. PA branch density was higher than controls but branch diameter was reduced. Diabetes also promoted astrogliosis. These results suggests that type 2 diabetes leads to cerebral neovascularization and remodeling but structural characteristics of newly formed vessels differ between lean and obese models that have mild or severe hyperglycemia, respectively. The prevention of dysfunctional cerebral neovascularization by early glucose control suggests that hyperglycemia is a mediator of this response. N=4-8 * p≤ 0.05, ** p≤ 0.005 *** 0.0005

Measurement accuracy of 3-Dimensional mapping technologies versus standard goniometry for angle assessment

2020 ◽  
Vol 16 (5) ◽  
pp. 547-554
Author(s):  
Allen E.D. Siapno ◽  
Brendan C. Yi ◽  
Doug Daniels ◽  
Aswani Bolagani ◽  
Lorna Kwan ◽  
...  
Keyword(s):  
Measurement Accuracy ◽  
3 Dimensional ◽  
Dimensional Mapping

A Numerical Study on Flow Characteristics Through Orifice Flowmeter and Measurement Accuracy Depending on Upstream Straight Length

2017 ◽  
Author(s):  
Jang Il Lee ◽  
Ae Ju Cheong ◽  
Bok Ki Min
Keyword(s):  
Numerical Analysis ◽  
Measurement Accuracy ◽  
Performance Test ◽  
Swirling Flow ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Orifice Plate ◽  
3 Dimensional ◽  
Ansys Cfx ◽  
Axial Velocity Profile

In this numerical study, Commercial CFD (Computational Fluid Dynamics) code, ANSYS CFX ver. 17.1, is used to analyze the 3-Dimensional flow characteristics through orifice plate (β = 0.6) with two 90 degree bends in different planes. The purpose of this numerical study is to evaluate measurement accuracy and flow characteristics of orifice flowmeter depending on upstream straight length from 12D to 56D. Thus, numerical calculations of pressure drop caused by swirling flow and distortion of axial velocity profile on orifice plate are performed by using numerical analysis. In addition, numerical analysis results are compared with recommended upstream straight length of ASME Performance Test Codes 19.5 for orifice plates and nozzles. The results show that if upstream straight length of orifice flowmeter is more than 40D, there is a little deviation of differential pressure. Moreover, it is found that up-down asymmetry of recirculation zones is relatively attenuated as the upstream straight length increases.

A Mathematical Approach to Automatic Configuration of Machining Fixtures: Analysis and Synthesis

1989 ◽  
Vol 111 (4) ◽  
pp. 299-306 ◽  
Author(s):  
Y-C. Chou ◽  
V. Chandru ◽  
M. M. Barash
Keyword(s):  
Screw Theory ◽  
Theory Analysis ◽  
Workpiece Surface ◽  
3 Dimensional ◽  
Prismatic Parts ◽  
Analysis And Synthesis ◽  
Engineering Mechanics ◽  
Machining Fixtures ◽  
Machining Operations

Drawing on screw theory and engineering mechanics, a mathematical theory for automatic configuration of machining fixtures for prismatic parts is developed. There are two parts in the theory: analysis and synthesis. The following functions of fixtures are analyzed: deterministic workpiece location, clamping stability, and total restraint. The synthesis of fixtures includes the determination of locating and clamping points on workpiece surface and the determination of clamping forces. The theory deals with the general case of 3-dimensional parts, polygon support (as opposed to three-point support), and multiple machining operations.

Stereo Matching Algorithm Based on Detecting Feature Points

2012 ◽  
Vol 433-440 ◽  
pp. 6190-6194
Author(s):  
Shuo Bo Xu ◽  
Di Shi Xu ◽  
Hua Fang
Keyword(s):  
Stereo Matching ◽  
Characteristic Point ◽  
Feature Points ◽  
Epipolar Line ◽  
Matching Problem ◽  
Matching Algorithm ◽  
Characteristic Points ◽  
Left And Right ◽  
Straight Lines ◽  
Verification Strategy

A new method for solving the stereo matching problem in the presence of large occlusion is presented. This method for stereo matching and occlusion detection is based on searching disparity point. In this paper, we suppose that a pair of epipolar-line images is a projection of a group of piece-wise straight lines on the left and right images respective. Therefore the disparity curve corresponding to a pair of epipolar-line images may be approximated by a group of piece-wise straight lines. Then the key of solving disparity curve is how to get the “characteristic points” on the group of piece-wise straight lines. Based on this view, we fetched out the conception “disparity point”, and three kinds of special disparity points are correctly corresponding to the “characteristic point”. By analyzing intensity property of a disparity point and its neighbor points, an approach which combines stepwise hypothesis-verification strategy with three constraint conditions is devised to extract the candidate disparity points from the epipolar images.

scholarly journals Application of Characteristic Model-Based Principal Component Analysis in Optimization of Flowmeter Parameters

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Wenping Jiang ◽  
Zhencun Jiang ◽  
Lingyang Wang ◽  
Jun Min ◽  
Yi Zhu ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Measurement Error ◽  
Measurement Accuracy ◽  
Structural Parameters ◽  
Principal Component ◽  
Component Analysis ◽  
Characteristic Model ◽  
Industrial Systems ◽  
Model Based ◽  
High Level

In complex industrial processes, it is necessary to perform modeling analysis on some industrial systems and find and optimize the factors that have the greatest impact on the results, in order to achieve the optimization of the industrial systems. However, due to the high-level nature or complex working mechanism of complex industrial systems, traditional principal component analysis methods are difficult to apply. Therefore, this paper proposes a characteristic model-based principal component analysis (CMPCA) to perform principal component analysis on complex industrial systems. The differential pressure flowmeter is taken as an example to verify the effectiveness of the method. Flowmeter is an indispensable instrument in measurement, and its accuracy depends on its own structural parameters. However, the measurement accuracy of some flow meters is not high, and the measurement error is large, which affects the normal industrial production process. This method is used to analyze the influence of the structural parameters of the flowmeter on its measurement accuracy, and the four most important structural parameters are found and optimized. The measurement error of the Bitoba flowmeter is reduced from 1% to 0.2%, and the measurement repeatability is reduced from 0.3 to 0.06, which proves the effectiveness of the method.

Study on 3-D Measurement Method in Shake Table Tests Using Image Processing Technique: 1st Report - Verification of Synthetic Performance of the Measurement System

2004 ◽  
Author(s):  
Satoshi Fujita ◽  
Osamu Furuya ◽  
Yasushi Niitsu
Keyword(s):  
Measurement System ◽  
Measurement Method ◽  
Measurement Accuracy ◽  
Dynamic Measurement ◽  
Processing Technique ◽  
Shake Table Test ◽  
Image Processing Technique ◽  
Shake Table ◽  
Shake Table Tests ◽  
3 Dimensional

This study has been doing research and development of 3-dimensional measurement method using the image processing technique for the measurement of dynamic displacement in shake table test. This measurement system is a very convenient system because it can measure the three-dimensional dynamic displacement in shake table test in which the several makers are only attached to the surface of an experimental structure. The system therefore is the most suitable measurement system for an evaluation of complex 3-dimensional behavior of experimental model. Fundamental hardware and software for the measurement system have been constructed until now. The fundamental dynamic measurement accuracy and effectiveness of the measurement system have been also confirmed from several shake table tests. This paper describes the dynamic measurement accuracy in shake table test in with the experimental model has several rotational behaviors, and also summarizes the synthetic performance of the proposed measurement system.

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