scholarly journals Conic tangents based high precision extraction method of concentric circle centers and its application in camera parameters calibration

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fei Hao ◽  
Jinjiang Su ◽  
Jingjing Shi ◽  
Chaohan Zhu ◽  
Jiatong Song ◽  
...  
Keyword(s):  
High Precision ◽  
Calibration Method ◽  
Concentric Circle ◽  
Calibration Target ◽  
Factors Affecting ◽  
Straight Line Passing ◽  
Physical Experiments ◽  
Straight Line ◽  
Concentric Circles ◽  
The Right

AbstractA high-precision camera intrinsic parameters calibration method based on concentric circles was proposed. Different from Zhang’s method, its feature points are the centers of concentric circles. First, the collinearity of the projection of the center of concentric circles and the centers of two ellipses which are imaged from the concentric circles was proved. Subsequently, a straight line passing through the center of concentric circles was determined with four tangent lines of concentric circles. Finally, the projection of the center of concentric circles was extracted with the intersection of the straight line and the line determined by the two ellipse centers. Simulation and physical experiments are carried out to analyze the factors affecting the accuracy of circle center coordinate extraction and the results show that the accuracy of the proposed method is higher. On this basis, several key parameters of the calibration target design are determined through simulation experiments and then the calibration target is printed to calibrate a binocular system. The results show that the total reprojection error of the left camera is reduced by 17.66% and that of the right camera is reduced by 21.58% compared with those of Zhang’s method. Therefore, the proposed calibration method has higher accuracy.

scholarly journals Flexible method for accurate calibration of large-scale vision metrology system based on virtual 3-D targets and laser tracker

2019 ◽  
Vol 16 (6) ◽  
pp. 172988141989351
Author(s):  
Xi Zhang ◽  
Yuanzhi Xu ◽  
Haichao Li ◽  
Lijing Zhu ◽  
Xin Wang ◽  
...  
Keyword(s):  
High Precision ◽  
Stereo Vision ◽  
Large Scale ◽  
Vision System ◽  
Calibration Method ◽  
Field Of View ◽  
Large Field ◽  
Laser Tracker ◽  
Calibration Target ◽  
Pose Tracking

For the purpose of obtaining high-precision in stereo vision calibration, a large-size precise calibration target, which can cover more than half of the field of view is vital. However, large-scale calibration targets are very difficult to fabricate. Based on the idea of error tracing, a high-precision calibration method for vision system with large field of view by constructing a virtual 3-D calibration target with a laser tracker was proposed in this article. A virtual 3-D calibration target that covers the whole measurement space can be established flexibly and the measurement precision of the vision system can be traceable to the laser tracker. First, virtual 3-D targets by calculating rigid body transformation with unit quaternion method were constructed. Then, the high-order distortion camera model was taken into consideration. Besides, the calibration parameters were solved with Levenberg–Marquardt optimization algorithm. In the experiment, a binocular stereo vision system with the field of view of 4 × 3 × 2 m3 was built for verifying the validity and precision of the proposed calibration method. It is measured that the accuracy with the proposed method can be greatly improved comparing with traditional plane calibration method. The method can be widely used in industrial applications, such as in the field of calibrating large-scale vision-based coordinate metrology, and six-degrees of freedom pose tracking system for dimensional measurement of workpiece, as well as robotics geometrical accuracy detection and compensation.

Calibration Method Using Concentric Circles Planar Template and its Application

2011 ◽  
Vol 460-461 ◽  
pp. 111-116
Author(s):  
Guang Yu Zhu ◽  
Jian Qing Zou ◽  
Peng Guo ◽  
Huai Ceng Zheng
Keyword(s):  
High Precision ◽  
Calibration Method ◽  
Random Errors ◽  
Cable Line ◽  
System Calibration ◽  
Vision Measurement ◽  
Dimension Measurement ◽  
Industrial Dimension ◽  
Concentric Circles ◽  
Scene Depth

This article introduces a new calibration method for machine vision measurement system--calibration method using concentric circles planar template. This method not only considering lens distortion and random errors introduced by the process of calibration, but also overcome limitation of strict demands for the standard parts’ position and complexity in stereovision computation, it also capable of conduct calibration to the whole scene depth space, effectively improve the efficiency of calibration with its simple and high precision mean. A relatively high precision can be achieved by applying this new method to diameter measurement of cable line, which is suitable to conduct on-field industrial dimension measurement calibration.

A Global Calibration Method of Multi-Vision Sensors in the Measurement of Engine Cylinder Joint Surface Holes

2011 ◽  
Vol 467-469 ◽  
pp. 1182-1188 ◽  
Author(s):  
Yong Qiang Shi ◽  
Chang Ku Sun ◽  
Bao Guang Wang ◽  
Peng Wang ◽  
Hong Xu Duan
Keyword(s):  
High Precision ◽  
Low Cost ◽  
Calibration Method ◽  
Joint Surface ◽  
Calibration Target ◽  
Whole Process ◽  
Global Calibration ◽  
Vision Sensors ◽  
Engine Cylinder

The measurement of engine cylinder joint surface holes is directly related to the control of product quality and the follow-up assembly. CMM is widely used in this field but can not meet the inspection requirements of automation, rapidity and Online testing. In this paper, a new measurement scheme based on the combination of multi-vision sensors is proposed. The global calibration method is focused on and a new dedicated calibration target is designed. The whole process of the system global calibration can be accomplished quickly through single imaging. The experiment results show that the method is feasible and with high precision. The method mentioned above can satisfy the engine production line requirements of intelligence, rapidity, high precision and low cost.

Bantuan Hukum Cuma-Cuma Bagi Tersangka yang Tidak Mampu Pada Tingkat Penyidikan

2020 ◽  
Vol 19 (2) ◽  
Author(s):  
Rio Saputra ◽  
Mokhammad Najih
Keyword(s):  
Secondary Data ◽  
Primary Data ◽  
Legal Aid ◽  
Criminal Cases ◽  
Legal Research ◽  
Factors Affecting ◽  
Legal Structure ◽  
Procedure Code ◽  
Study Techniques ◽  
The Right

<p><em>Suspects have the right to obtain legal assistance, especially for suspects who are classified as economically disadvantaged in accordance with Article 56 of the Criminal Procedure Code (KUHAP). The facts show that there are many irregularities in the implementation of legal aid, therefore it is necessary to know about the implementation of free legal aid for suspects who are incapacitated at the level of investigation and the factors that become obstacles in the implementation of legal aid. This legal research is an empirical legal research and this research is descriptive in nature. The data used are primary data and secondary data. The techniques used to collect data were document study techniques and interview techniques. Inhibiting factors affecting the implementation of free legal aid for suspects who are unable at the level of investigation can be classified and differentiated into 3 factors, namely, legal substance, legal structure, and legal culture).</em></p><p><strong><em>Keywords: </em></strong><em>Legal Aid, Criminal Cases</em></p>

scholarly journals Demographic, Social, Economic, and Regional Factors Affecting the Diffusion of Hybrid Electric Vehicles in Japan

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2130
Author(s):  
Ken’ichi Matsumoto ◽  
Yui Nakamine ◽  
Sunyong Eom ◽  
Hideki Kato
Keyword(s):  
Electric Vehicles ◽  
Urban Areas ◽  
Carbon Dioxide Emissions ◽  
Regional Differences ◽  
Fixed Effects ◽  
Hybrid Electric Vehicles ◽  
Alternative Fuel Vehicles ◽  
Factors Affecting ◽  
Hybrid Electric ◽  
The Right

The transportation sector is a major contributor to carbon dioxide emissions, and the resulting climate change. The diffusion of alternative fuel vehicles, including hybrid electric vehicles (HEV), is an important solution for these issues. This study aimed to evaluate the factors affecting the ownership ratio of HEVs, particularly passenger vehicles, and the regional differences in the purchase of HEVs in Japan. This study performed a fixed-effects regression analysis with panel data for 47 prefectures during the period 2005–2015 to evaluate the factors affecting the HEV ownership ratio and conducted three cluster analyses to investigate the regional differences in diffusion in terms of price categories, body types, and drive systems of HEVs. Some demographic and social factors were found to affect the ownership ratio in Japan, whereas economic factors, including prefecture-level subsidies for purchasing HEVs, were not. Regarding regional differences, prefectures in urban areas with higher income levels tend to purchase more expensive and large-sized HEVs. These results suggest that a strategy to sell the right vehicle to the right person and region is essential for further promoting HEVs in Japan.

scholarly journals Intraocular Lens Dislocation after Cataract Surgery in Tambolaka, Southwest Sumba, Indonesia: A Case Report

2018 ◽  
Vol 9 (1) ◽  
pp. 179-184
Author(s):  
Ratna Sitompul
Keyword(s):  
Case Report ◽  
Intraocular Lens ◽  
Rural Areas ◽  
Rare Complication ◽  
Cataract Extraction ◽  
Factors Affecting ◽  
Intraocular Lens Dislocation ◽  
Post Surgery ◽  
The Right ◽  
Iol Dislocation

Intraocular lens (IOL) dislocation is a rare complication of cataract extraction requiring prompt surgery. This case report aims to raise awareness of such cases and the importance of post-surgery follow-up. A 58-year-old female patient was found with anterior IOL dislocation a week after phacoemulsification surgery in her right eye. Visual acuity of the right eye was 1/60 with ciliary injection and IOL dislocation to the anterior chamber of the right eye. The patient underwent surgery of the right eye and the IOL haptic was found to be broken. In this case report, the factors affecting IOL dislocation are axis length, broken IOL haptic, and patient activity that increased intraocular pressure. Cataract extraction surgery, although common, needs to be conducted carefully, and it is important for ophthalmologists and general practitioners to detect this condition, especially in rural areas where facilities are limited, as IOL dislocation could occur and requires immediate treatment to achieve a better result.

scholarly journals Physical properties of surfaces. II—Viscous flow of liquid films. The range of action of surface forces

1935 ◽  
Vol 151 (872) ◽  
pp. 220-233 ◽  
Author(s):  
S. H. Bastow ◽  
Frank Philip Bowden ◽  
Thomas Martin Lowry
Keyword(s):  
Viscous Flow ◽  
Freezing Point ◽  
Applied Pressure ◽  
Liquid Films ◽  
Appreciable Effect ◽  
Straight Line Passing ◽  
Straight Line ◽  
Fluid Properties ◽  
Line Passing ◽  
Induced Structure

The present paper describes experiments which were carried out in order to determine the extent to which the fluid properties of water and other liquids may be modified by the presence of a solid surface. For this purpose, measurements of the viscous flow of a liquid very near to a surface are particularly suitable, since they provide a sensitive test for the existence of any induced structure in the liquid. If the surface has no appreciable effect, the smallest applied pressure will cause the liquid to flow and the rate of flow plotted against pressure will give a straight line passing through the origin, see fig. 3. If, however, as many authors have suggested, long chains of oriented liquid molecules with a definite rigidity are formed by the influence of the surface, the liquid will show a resistance to shear, which will be specially evident at low pressures; Poiseuille’s law will not hold and the pressure-flow curve will be of the form shown in fig. 4. A method has been developed for measuring the viscosity of thin liquid films enclosed between flat polished surfaces of glass and steel. The film thickness can be varied from about 10 -5 cm to any desired distance and can be accurately determined. The experiments show that films of a liquid, known to possess a bulk structure (liquid crystal), possess a high rigidity, but there is no sign of induced structure in normal liquids even with very thin films and at temperatures near the freezing point.

Analysis of Factors Affecting Technological Innovativeness in Engineering Enterprises in Tanzania

2010 ◽  
Vol 34 (1) ◽  
pp. 1-14
Author(s):  
Emmanuel A. Mjema
Keyword(s):  
Innovation Management ◽  
Positive Culture ◽  
Key Factors ◽  
Factors Affecting ◽  
Level Of Education ◽  
Fundamental Innovation ◽  
Local Material ◽  
The Right

This paper discusses the technological innovativeness in engineering enterprises in Tanzania and analyses the factors affecting the innovativeness. It starts by analyzing various concepts regarding innovation, then analyzed from documentary review factors affecting innovativeness and then analyzed the innovativeness in Tanzanian enterprises.From the documentary review it was learnt that the following key factors influence technological innovativeness: Existence of innovation management; Existence of market to absorb the products of innovation; Existence of partnership between the universities and the firms; Existence of positive culture and politics towards innovation; The governmentplaying its role to influence innovation; Existence of the right knowledge; and Ability of the enterprises to access to financing institutions that support innovation.The research shows that there is hardly any fundamental innovation in Tanzania, what is presented as innovation is the copying of technologies and manufacture them using local material. Theresearcher established the following factors affecting the innovativeness of engineering enterprises in Tanzania: Level of education among the entrepreneurs in engineering enterprises; financing for the enterprises in Tanzania; partnership with R&D institutions; innovativeness culture; and market for Tanzanian products.

CRITICAL REVIEW OF EMULSION STABILITY AND CHARACTERIZATION TECHNIQUES IN OIL PROCESSING

2021 ◽  
pp. 1-36
Author(s):  
Vahideh Angardi ◽  
Ali Ettehadi ◽  
Özgün Yücel
Keyword(s):  
Separation Efficiency ◽  
Petroleum Industry ◽  
Cost Effective ◽  
Downstream Processing ◽  
Physical Factors ◽  
Comprehensive Review ◽  
Factors Affecting ◽  
Mathematical Explanations ◽  
The Stability ◽  
The Right

Abstract Effective separation of water and oil dispersions is considered a critical step in the determination of technical and economic success in the petroleum industry over the years. Moreover, a deeper understanding of the emulsification process and different affected parameters is essential for cost-effective oil production, transportation, and downstream processing. Numerous studies conducted on the concept of dispersion characterization indicate the importance of this concept, which deserves attention by the scientific community. Therefore, a comprehensive review study with critical analysis on significant concepts will help readers follow them easily. This study is a comprehensive review of the concept of dispersion characterization and conducted studies recently published. The main purposes of this review are to 1) Highlight flaws, 2) Outline gaps and weaknesses, 3) Address conflicts, 4) Prevent duplication of effort, 5) List factors affecting dispersion. It was found that the separation efficiency and stability of dispersions are affected by different chemical and physical factors. Factors affecting the stability of the emulsions have been studied in detail and will help to look for the right action to ensure stable emulsions. In addition, methods of ensuring stability, especially coalescence are highlighted, and coalescence mathematical explanations of phenomena are presented.

Industrial part localization and grasping using a robotic arm guided by 2D monocular vision

2018 ◽  
Vol 45 (6) ◽  
pp. 794-804 ◽  
Author(s):  
Zhaohui Zheng ◽  
Yong Ma ◽  
Hong Zheng ◽  
Yu Gu ◽  
Mingyu Lin
Keyword(s):  
Camera Calibration ◽  
High Precision ◽  
Calibration Method ◽  
Monocular Vision ◽  
Robotic Arm ◽  
Robot Arm ◽  
Content Type ◽  
Calibration Algorithm ◽  
Target Locating ◽  
Practical Implications

Purpose The welding areas of the workpiece must be consistent with high precision to ensure the welding success during the welding of automobile parts. The purpose of this paper is to design an automatic high-precision locating and grasping system for robotic arm guided by 2D monocular vision to meet the requirements of automatic operation and high-precision welding. Design/methodology/approach A nonlinear multi-parallel surface calibration method based on adaptive k-segment master curve algorithm is proposed, which improves the efficiency of the traditional single camera calibration algorithm and accuracy of calibration. At the same time, the multi-dimension feature of target based on k-mean clustering constraint is proposed to improve the robustness and precision of registration. Findings A method of automatic locating and grasping based on 2D monocular vision is provided for robot arm, which includes camera calibration method and target locating method. Practical implications The system has been integrated into the welding robot of an automobile company in China. Originality/value A method of automatic locating and grasping based on 2D monocular vision is proposed, which makes the robot arm have automatic grasping function, and improves the efficiency and precision of automatic grasp of robot arm.

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