Detection method of PCB component based on automatic optical stitching algorithm

Circuit World ◽  
2015 ◽  
Vol 41 (4) ◽  
pp. 133-136 ◽  
Author(s):  
Ge Qiang ◽  
Zheng Shanshan ◽  
Zhao Yang ◽  
Chen Mao
Keyword(s):  
Solder Joint ◽  
High Speed ◽  
Feature Matching ◽  
Region Of Interest ◽  
Scale Space ◽  
Image Stitching ◽  
Small Data ◽  
Full Line ◽  
Content Type ◽  
Line Image

Purpose – This paper aims to propose image stitching by reduction of full line and taking line image as registration image to solve the problem of automatic optic inspection in PCB detection. In addition, surf registration was introduced for image stitching to improve the accuracy and speed of stitching. Design/methodology/approach – First, image stitching proceeded by method of full line reduction and taking line image as registration image; second, surf registration was introduced based on the traditional PCB image stitching algorithm. Scale space of the image pyramid was adopted for confirming relative future points between stitching image. The registration means of nearest neighbourhood and next neatest neighborhood was selected for feature matching and fused in region of interest to fulfil image stitching. Findings – The improved stitching algorithm with small data size of image, high speed and noncumulative transitive error eliminated displacement deviation and solved the stitching gap caused by uneven illumination, to greatly improve the accuracy and speed of stitching. Research limitations/implications – The research of this paper can only used for appearance detection and cannot be used for solder joint inspection with circuit detection or invisible solder joint detection; it can identify and mark PCB component defects but cannot classify automatically, thus artificial confirmation and processing is needed. Originality/value – Based on the traditional image stitching means, this paper proposed full line reduction for image stitching, which reduces processing of data and speeds up image stitching; in addition, surf registration was introduced into the study of PCB stitching algorithm, which greatly improves the accuracy and speed of stitching and solves stitching gap formed by opposite variation trend of image local edge caused by uneven illumination.

scholarly journals Deep Learning-Based Automated Background Removal for Structural Exterior Image Stitching

2021 ◽  
Vol 11 (8) ◽  
pp. 3339
Author(s):  
Myung Soo Kang ◽  
Yun-Kyu An
Keyword(s):  
Deep Learning ◽  
Feature Matching ◽  
Digital Images ◽  
Computational Cost ◽  
Region Of Interest ◽  
Depth Estimation ◽  
Image Stitching ◽  
Background Removal ◽  
Working Distance ◽  
Removal Technique

This paper presents a deep learning-based automated background removal technique for structural exterior image stitching. In order to establish an exterior damage map of a structure using an unmanned aerial vehicle (UAV), a close-up vision scanning is typically required. However, unwanted background objects are often captured within the scanned digital images. Since the unnecessary background objects often cause serious distortion on the image stitching process, they should be removed. In this paper, the automated background removal technique using deep learning-based depth estimation is proposed. Based on the fact that the region of interest has closer working distance than the background ones from the camera, the background region within the digital images can be automatically removed using a deep learning-based depth estimation network. In addition, an optimal digital image selection based on feature matching-based overlap ratio is proposed. The proposed technique is experimentally validated using UAV-scanned digital images acquired from an in-situ high-rise building structure. The validation test results show that the optimal digital images obtained from the proposed technique produce the precise structural exterior map with computational cost reduction of 85.7%, while raw scanned digital images fail to construct the structural exterior map and cause serious stitching distortion.

Influence of ageing treatment on microstructure, mechanical properties and adhesive wear behaviour of 6063 aluminium alloy

2014 ◽  
Vol 66 (4) ◽  
pp. 520-524 ◽  
Author(s):  
Serkan Büyükdoğan ◽  
Süleyman Gündüz ◽  
Mustafa Türkmen
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
High Speed ◽  
Al Alloys ◽  
Wear Behaviour ◽  
Al Alloy ◽  
Strain Ageing ◽  
Content Type ◽  
Static Strain ◽  
Structural Applications

Purpose – The paper aims to provide new observations about static strain ageing in aluminium (Al) alloys which are widely used in structural applications. Design/methodology/approach – The present work aims to provide theoretical and practical information to industries or researchers who may be interested in the effect of static strain ageing on mechanical properties of Al alloys. The data are sorted into the following sections: introduction, materials and experimental procedure, results and discussion and conclusions. Findings – Tensile strength, proof strength (0.2 per cent) and percentage elongation measurement were used to investigate the effect of strain ageing on the mechanical properties. Wear tests were performed by sliding the pin specimens, which were prepared from as-received, solution heat-treated, deformed and undeformed specimens after ageing, on high-speed tool steel (64 HRC). It is concluded that the variations in ageing time improved the strength and wear resistance of the 6063 Al alloy; however, a plastically deformed solution-treated alloy has higher strength and wear resistance than undeformed specimens for different ageing times at 180°C. Practical implications – A very useful source of information for industries using or planning to produce Al alloys. Originality/value – This paper fulfils an identified resource need and offers practical help to the industries.

Impacts of high-speed railway on the industrial pollution emissions in China

Kybernetes ◽  
2020 ◽  
Vol 49 (11) ◽  
pp. 2713-2735 ◽  
Author(s):  
Xiaomin Fan ◽  
Yingzhi Xu ◽  
Yongqing Nan ◽  
Baoli Li ◽  
Haiya Cai
Keyword(s):  
Environmental Effects ◽  
Industrial Pollution ◽  
High Speed ◽  
Assessment Method ◽  
Economic Effects ◽  
High Speed Railway ◽  
Central Cities ◽  
Content Type ◽  
Pollution Emissions ◽  
The Impact

Purpose The purpose of this paper is to analyse the impact of high-speed railway (HSR) on industrial pollution emissions using the data for 285 prefecture-level cities in China from 2004 to 2016. Design/methodology/approach The research method used in this paper is the multi-period difference-in-differences (DID) model, which is an effective policy effect assessment method. To further address the issue of endogeneity, the DID integrated with the propensity score matching (PSM-DID) approach is employed to eliminate the potential self-selection bias. Findings The results show that the HSR has significantly reduced industrial pollution emissions, which is validated by several robustness tests. Compared with peripheral cities, HSR exerts a greater impact on industrial pollution emissions in central cities. In addition, the mechanism test reveals that the optimised allocation of inter-city industries is an important channel for HSR to mitigate industrial pollution emissions, and this is closely related to the location of HSR stations. Originality/value Previous studies have paid more attention to evaluating the economic effects of HSR, however, most of these studies overlook its environmental effects. Consequently, the impact of HSR on industrial pollution emissions is led by using multi-period DID models in this paper, in which the environmental effects are measured. The results of this paper can provide a reference for the pollution reduction policies and also the coordinated development of economic growth and environmental quality.

Comparison of the reluctance laminated and solid rotor synchronous machine operating at high temperatures

2019 ◽  
Vol 38 (4) ◽  
pp. 1111-1119 ◽  
Author(s):  
Marcin Lefik ◽  
Krzysztof Komeza ◽  
Ewa Napieralska-Juszczak ◽  
Daniel Roger ◽  
Piotr Andrzej Napieralski
Keyword(s):  
High Speed ◽  
Design Methodology ◽  
Three Dimensional ◽  
Synchronous Machine ◽  
Point Of View ◽  
Heat Sources ◽  
Model Calculations ◽  
Content Type ◽  
Thermal Phenomenon ◽  
Practical Implications

Purpose The purpose of this paper is to present a comparison between reluctance synchronous machine-enabling work at high internal temperature (HT° machine) with laminated and solid rotor. Design/methodology/approach To obtain heat sources for the thermal model, calculations of the electromagnetic field were made using the Opera 3D program including effect of rotation and the resulting eddy current losses. To analyse the thermal phenomenon, the 3D coupled thermal-fluid (CFD) model is used. Findings The presented results show clearly that laminated construction is much better from a point of view of efficiency and temperature. However, solid construction can be interesting for high speed machines due to their mechanical robustness. Research limitations/implications The main problem, despite the use of parallel calculations, is the long calculation time. Practical implications The obtained simulation and experimental results show the possibility of building a machine operating at a much higher ambient temperature than it was previously produced for example in the vicinity of the aircraft turbines. Originality/value The paper presents the application of fully three-dimensional coupled electromagnetic and thermal analysis of new machine constructions designed for elevated temperature.

Characteristic properties of AlTiN and TiN coated HSS materials

2015 ◽  
Vol 67 (2) ◽  
pp. 172-180 ◽  
Author(s):  
Mumin Sahin ◽  
Cenk Misirli ◽  
Dervis Özkan
Keyword(s):  
Surface Roughness ◽  
Tensile Strength ◽  
High Speed ◽  
Cutting Tools ◽  
High Speed Steel ◽  
Wear Properties ◽  
Content Type ◽  
X Ray ◽  
Number Of Cycles ◽  
Future Work

Purpose – The purpose of this paper is to examine mechanical and metallurgical properties of AlTiN- and TiN-coates high-speed steel (HSS) materials in detail. Design/methodology/approach – In this study, HSS steel parts have been processed through machining and have been coated with AlTiN and TiN on physical vapour deposition workbench at approximately 6,500°C for 4 hours. Tensile strength, fatigue strength, hardness tests for AlTiN- and TiN-coated HSS samples have been performed; moreover, energy dispersive X-ray spectroscopy and X-ray diffraction analysis and microstructure analysis have been made by scanning electron microscopy. The obtained results have been compared with uncoated HSS components. Findings – It was found that tensile strength of TiAlN- and TiN-coated HSS parts is higher than that of uncoated HSS parts. Highest tensile strength has been obtained from TiN-coated HSS parts. Number of cycles for failure of TiAlN- and TiN-coated HSS parts is higher than that for HSS parts. Particularly TiN-coated HSS parts have the most valuable fatigue results. However, surface roughness of fatigue samples may cause notch effect. For this reason, surface roughness of coated HSS parts is compared with that of uncoated ones. While the average surface roughness (Ra) of the uncoated samples was in the range of 0.40 μm, that of the AlTiN- and TiN-coated samples was in the range of 0.60 and 0.80 μm, respectively. Research limitations/implications – It would be interesting to search different coatings for cutting tools. It could be the good idea for future work to concentrate on wear properties of tool materials. Practical implications – The detailed mechanical and metallurgical results can be used to assess the AlTiN and TiN coating applications in HSS materials. Originality/value – This paper provides information on mechanical and metallurgical behaviour of AlTiN- and TiN-coated HSS materials and offers practical help for researchers and scientists working in the coating area.

A low complexity image stitching using advanced feature matching in mobile environments

2014 ◽  
Vol 10 (2) ◽  
pp. 129-136 ◽  
Author(s):  
Hyochang Ahn ◽  
Yong-Hwan Lee ◽  
June-Hwan Lee ◽  
Han-Jin Cho
Keyword(s):  
Feature Matching ◽  
Low Complexity ◽  
Image Stitching ◽  
Mobile Environments

An improved model on forecasting temperature rise of high-speed angular contact ball bearings considering structural constraints

2018 ◽  
Vol 70 (1) ◽  
pp. 15-22 ◽  
Author(s):  
De-xing Zheng ◽  
Weifang Chen ◽  
Miaomiao Li
Keyword(s):  
Heat Generation ◽  
Temperature Rise ◽  
High Speed ◽  
Structural Constraints ◽  
Ball Bearings ◽  
Content Type ◽  
Grid Model ◽  
Simulation Results ◽  
Operation Parameters ◽  
Improved Model

Purpose Thermal performances are key factors impacting the operation of angular contact ball bearings. Heat generation and transfer about angular contact ball bearings, however, have not been addressed thoroughly. So far, most researchers only considered the convection effect between bearing housings and air, whereas the cooling/lubrication operation parameters and configuration effect were not taken into account when analyzing the thermal behaviors of bearings. This paper aims to analyze the structural constraints of high-speed spindle, structural features of bearing, heat conduction and convection to study the heat generation and transfer of high-speed angular contact ball bearings. Design/methodology/approach Based on the generalized Ohm’s law, the thermal grid model of angular contact ball bearing of high-speed spindle was first established. Next Gauss–Seidel method was used to solve the equations group by Matlab, and the nodes temperature was calculated. Finally, the bearing temperature rise was tested, and the comparative analysis was made with the simulation results. Findings The results indicate that the simulation results of bearing temperature rise for the proposed model are in better agreement with the test values. So, the thermal grid model established is verified. Originality/value This paper shows an improved model on forecasting temperature rise of high-speed angular contact ball bearings. In modeling, the cooling/lubrication operation parameters and structural constraints are integrated. As a result, the bearing temperature variation can be forecasted more accurately, which may be beneficial to improve bearing operating accuracy and bearing service life.

Effects of doping trace Ni element on interfacial behavior of Sn/Ni (polycrystal/single-crystal) joints

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jianing Wang ◽  
Jieshi Chen ◽  
Zhiyuan Zhang ◽  
Peilei Zhang ◽  
Zhishui Yu ◽  
...  
Keyword(s):  
Solder Joint ◽  
Single Crystal ◽  
Microstructure Evolution ◽  
Thermal Aging ◽  
Interfacial Layer ◽  
Aging Treatment ◽  
Growth Behavior ◽  
Reflow Process ◽  
Content Type ◽  
Ni Substrate

Purpose The purpose of this article is the effect of doping minor Ni on the microstructure evolution of a Sn-xNi (x = 0, 0.05 and 0.1 wt.%)/Ni (Poly-crystal/Single-crystal abbreviated as PC Ni/SC Ni) solder joint during reflow and aging treatment. Results showed that the intermetallic compounds (IMCs) of the interfacial layer of Sn-xNi/PC Ni joints were Ni3Sn4 phase, while the IMCs of Sn-xNi/SC Ni joints were NiSn4 phase. After the reflow process and thermal aging of different joints, the growth behavior of interfacial layer was different due to the different mechanism of element diffusion of the two substrates. The PC Ni substrate mainly provided Ni atoms through grain boundary diffusion. The Ni3Sn4 phase of the Sn0.05Ni/PC Ni joint was finer, and the diffusion flux of Sn and Ni elements increased, so the Ni3Sn4 layer of this joint was the thickest. The SC Ni substrate mainly provided Ni atoms through the lattice diffusion. The Sn0.1Ni/SC Ni joint increases the number of Ni atoms at the interface due to the doping of 0.1Ni (wt.%) elements, so the joint had the thickest NiSn4 layer. Design/methodology/approach The effects of doping minor Ni on the microstructure evolution of an Sn-xNi (x = 0, 0.05 and 0.1 Wt.%)/Ni (Poly-crystal/Single-crystal abbreviated as PC Ni/SC Ni) solder joint during reflow and aging treatment was investigated in this study. Findings Results showed that the intermetallic compounds (IMCs) of the interfacial layer of Sn-xNi/PC Ni joints were Ni3Sn4 phase, while the IMCs of Sn-xNi/SC Ni joints were NiSn4 phase. After the reflow process and thermal aging of different joints, the growth behavior of the interfacial layer was different due to the different mechanisms of element diffusion of the two substrates. Originality/value In this study, the effect of doping Ni on the growth and formation mechanism of IMCs of the Sn-xNi/Ni (single-crystal) solder joints (x = 0, 0.05 and 0.1 Wt.%) was investigated.

China's economy will struggle to halt secular slowdown

2021 ◽  
Keyword(s):  
High Speed ◽  
Regression To The Mean ◽  
Content Type ◽  
Strong Force ◽  
Global Demand ◽  
The Mean ◽  
Productivity Gains ◽  
Global Growth ◽  
China’S Economy

Significance Comparisons with two formerly fast-growing Asian neighbours, Japan and South Korea, suggest that China will continue to slow for another decade. Analysis of global growth trends over 50 years points to a strong force of ‘regression to the mean’, meaning that continued high-speed growth is statistically unlikely. Impacts Continued Chinese economic slowing will reduce global demand for resources such as iron ore and coal. Achieving productivity growth will require deepening reforms to increase the role of the market, the private sector and competition. World Bank economists emphasise that imposing stricter financial discipline is a key step to enhancing market-based productivity gains.

Accurate composition dependent thermo mechanical lifetime estimation of hour glass type solder joint in electronic assemblies

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Leonid Anatolevich Olenev ◽  
Rafina Rafkatovna Zakieva ◽  
Nina Nikolaevna Smirnova ◽  
Rustem Adamovich Shichiyakh ◽  
Kirill Aleksandrovich Ershov ◽  
...  
Keyword(s):  
Finite Element ◽  
Chemical Composition ◽  
Solder Joint ◽  
Design Methodology ◽  
Lifetime Estimation ◽  
Creep Tests ◽  
Content Type ◽  
Element Simulation ◽  
Glass Type ◽  
Electronic Assemblies

Purpose This study aims to present a more accurate lifetime prediction model considering solder chemical composition. Design/methodology/approach Thermal cycling and standard creep tests as well as finite element simulation were used. Findings The study found lower error in the solder joint lifetime evaluation. The higher the Ag content is, the higher the lifetime is achieved. Originality/value It is confirmed.

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