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1 – 10 of 590
Article
Publication date: 18 January 2016

Maria Doubenskaia, Sergey Grigoriev, Ivan Zhirnov and Igor Smurov

This paper aims to propose methods for on-line monitoring and process quality assurance of Selective Laser Melting (SLM) technology as a competitive advantage to enhance its…

Abstract

Purpose

This paper aims to propose methods for on-line monitoring and process quality assurance of Selective Laser Melting (SLM) technology as a competitive advantage to enhance its implementation into modern manufacturing industry.

Design/methodology/approach

Monitoring of thermal emission from the laser impact zone was carried out by an originally developed pyrometer and a charge-coupled device (CCD) camera which were integrated with the optical system of the PHENIX PM-100 machine. Experiments are performed with variation of the basic process parameters such as powder layer thickness (0-120 μm), hatch distance (60-1,000 μm) and fabrication strategy (the so-called “one-zone” and “two-zone”).

Findings

The pyrometer signal from the laser impact zone and the 2D temperature mapping from HAZ are rather sensible to variation of high-temperature phenomena during powder consolidation imposed by variation of the operational parameters.

Research limitations/implications

Pyrometer measurements are in arbitrary units. This limitation is due to the difficulty to integrate diagnostic tools into the optical system of a commercial SLM machine.

Practical implications

Enhancement of SLM process stability and efficiency through comprehensive optical diagnostics and on-line control.

Originality/value

High-temperature phenomena in SLM were monitored coaxially with the laser beam for variation of several operational parameters.

Details

Rapid Prototyping Journal, vol. 22 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 1 September 2005

Cao Qixin, Fu Zhuang, Xia Nianjiong and F.L. Lewis

In this paper, an optical inspection method of the ball grid array package(BGA) is proposed using a binocular machine vision system.

Abstract

Purpose

In this paper, an optical inspection method of the ball grid array package(BGA) is proposed using a binocular machine vision system.

Design/methodology/approach

The height of each solder ball is calculated based on spatial geometrical size and location obtained from the two CCD cameras capturing range images of a LED illuminated BGA chip at certain orientation.

Findings

The structure of this system is simple and the accuracy is 0.02 mm, The experimental results have proved the validity of this system for BGA failure detection.

Practical implications

The developed machine vision system can provide some of the critical factors for BGA quality evaluation, such as the height of solder ball, diameter, pitch and coplanarity.

Originality/value

Compared with other systems, the structure of this system is simple and accurate, which meets the demand of off‐line and on‐line inspection. The limitation of this system is that the margin of field of view (FOV) is fuzzy. Further study could be focused on this problem.

Details

Assembly Automation, vol. 25 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 10 August 2010

Fan Wen, Zhenshen Qu and Changhong Wang

The purpose of this paper is to describe how, in order to fulfill the specific missions under some special environments without people participating, a multi‐robot object tracking…

Abstract

Purpose

The purpose of this paper is to describe how, in order to fulfill the specific missions under some special environments without people participating, a multi‐robot object tracking and docking systems are designed based on networked control frames.

Design/methodology/approach

In the process of target recognition and tracking, the tracking robot obtains the target robot's position and poses information by means of multi‐sensors, and tracking the target robot uses a data fusion algorithm based on network‐delay. In the phase of docking, the exterior parameters of the CCD camera installed on the tracking robot can be calculated in‐phase by recognizing the coded target in a place on the target robot. Finally, the relative position and pose parameters between the tracking robot and the target robot can be derived using the coordinate rotation parameters.

Findings

The experiment results indicated that the relative position measure error is less than 1.5 percent, and the relative pose measure error less than 1° within 1.5‐10 m. The research results show that the system can actualize object tracing and docking missions accurately and timely.

Research limitations/implications

This paper is devoted to multi‐robot object tracking and docking systems.

Practical implications

The main applications are in the exploration in the seabed, consignment in the workshop, formation of spacecrafts, docking of spacecrafts, and so on.

Originality/value

The system can actualize object tracing and docking missions accurately, and the system is of reliable, real‐time, and robust capabilities. This will aid all developers and researchers to enhance their technicality.

Details

Kybernetes, vol. 39 no. 8
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 11 June 2018

Somrerk Chandra-ambhorn, Sermsak Srihirun and Thamrongsin Siripongsakul

The purpose of this study is to investigate the aesthetic blackening coating formed by a hydrothermal process, focusing on the formation of magnetite and the oxide adhesion for…

Abstract

Purpose

The purpose of this study is to investigate the aesthetic blackening coating formed by a hydrothermal process, focusing on the formation of magnetite and the oxide adhesion for improving the corrosion resistance of the steel.

Design/methodology/approach

The aesthetic black coating was applied on AISI 4140 steel using a hydrothermal process with a non-toxic solution consisted of ferrous sulphate hydrate (FeSO4·7H2O), sodium hydroxide (NaOH) and hydrazine hydrate (N2H4·H2O). Upon process parameters temperature and time, the morphology of the coatings and oxidation kinetics were investigated by using scanning electron microscopy and X-ray diffraction (XRD) analysis. Furthermore, the samples with coatings were subjected to the adhesion test using a tensile testing machine equipped with a charge-coupled device (CCD) camera.

Findings

From the formation parameters due to temperature and time for the conversion coatings, it was found that the oxidation kinetics had special characteristics which were in accordance with a linear rate law and Arrhenius relation. For the samples blackened, the XRD analysis results revealed that the magnetite was successfully formed on the surface of the steel. On the other hand, increasing the blackening temperature worsened the scale adhesion as observed by the lower strain provoking the first spallation and the higher sensitivity of the oxide to spall out with the imposed strain.

Originality/value

The effects of parameters of the formation of conversion coatings were investigated to understand the kinetics of the coatings. Furthermore, a tensile adhesion test using a CCD camera was applied to evaluate the adhesion between the native oxide formed by conversion coating.

Details

Anti-Corrosion Methods and Materials, vol. 65 no. 4
Type: Research Article
ISSN: 0003-5599

Keywords

Content available
Article
Publication date: 1 March 2000

213

Abstract

Details

Sensor Review, vol. 20 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 11 January 2019

Somrerk Chandra-ambhorn, Jennarong Tungtrongpairoj, Anuwat Jutilarptavorn, Thanasak Nilsonthi and Tanongsak Somphakdee

The purpose of this study is to investigate the formation, pickling ability and adhesion of thermal oxide scales on the hot-rolled recycled steels produced from the medium and…

Abstract

Purpose

The purpose of this study is to investigate the formation, pickling ability and adhesion of thermal oxide scales on the hot-rolled recycled steels produced from the medium and thin slabs. Because the scale on the steel produced from the medium slab was relatively thick of about 11 µm, it contained cracks after hot-rolling. Thus during pickling, the scale was uniformly attacked with the simultaneous dissolution of the inner scale because of the penetration of acid through cracks. However, the scale on the steel produced from the thin slab was thinner of about 6 µm and thus, nearly crack-free. The pickling solution thus attacked the scale surface uniformly. At longer pickling periods, pits were also nucleated and propagated. Concurrently, the tensile testing machine with a CCD camera has been applied to observe scale adhesion.

Design/methodology/approach

The formation, pickling ability and adhesion of thermal oxide scales on the hot-rolled recycled steels produced from the recycled slab, e.g. medium slab and thin slab, were investigated. The morphology and phase identification were examined by using scanning electron microscopy, X-ray diffraction and Raman spectroscopy. Furthermore, the adhesion behaviour of oxide scale was investigated by immersion test and tensile test with a CCD camera.

Findings

For the scale formation, it was found that the hematite and magnetite were formed on the hot-rolled recycled steels produced from the medium and thin slabs. For the immersion test, it was found that the scale on hot-rolled recycled steels produced from the medium slab was more difficult to be pickled as represented by the longer time for the complete pickling. This was consistent with the result of tensile test; the steel produced from the medium slab had better scale adhesion as represented by the higher strain initiating the first spallation of scale.

Originality/value

The effects of slab types and its alloying element were investigated to understand the scale adhesion behaviour. The empirical pickling mechanisms and the mechanical adhesion energy were proposed. It led to the understanding in the control of alloying element in the hot-rolled steel.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 3
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 8 April 2021

Boyoung Kim, Minyong Choi, Seung-Woo Son, Deokwon Yun and Sukjune Yoon

Many manufacturing sites require precision assembly. Particularly, similar to cell phones, assembly at the sub-mm scale is not easy, even for humans. In addition, the system…

219

Abstract

Purpose

Many manufacturing sites require precision assembly. Particularly, similar to cell phones, assembly at the sub-mm scale is not easy, even for humans. In addition, the system should assemble each part with adequate force and avoid breaking the circuits with excessive force. The purpose of this study is to assemble high precision components with relatively reasonable vision devices compared to previous studies.

Design/methodology/approach

This paper presents a vision-force guided precise assembly system using a force sensor and two charge coupled device (CCD) cameras without an expensive 3-dimensional (3D) sensor or computer-aided design model. The system accurately estimates 6 degrees-of-freedom (DOF) poses from a 2D image in real time and assembles parts with the proper force.

Findings

In this experiment, three connectors are assembled on a printed circuit board. This system obtains high accuracy under 1 mm and 1 degree error, which shows that this system is effective.

Originality/value

This is a new method for sub-mm assembly using only two CCD cameras and one force sensor.

Details

Assembly Automation, vol. 41 no. 2
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 26 October 2018

Hongyao Shen, Weijun Sun and Jianzhong Fu

Fused deposit modeling (FDM) additive manufacturing technology is widely applied in recent years. However, there are many defects that may affect the surface quality, accuracy, or…

Abstract

Purpose

Fused deposit modeling (FDM) additive manufacturing technology is widely applied in recent years. However, there are many defects that may affect the surface quality, accuracy, or even cause the collapse of the parts. This paper presents a solution to the problem of detecting defects on the outer surface in the additive process of FDM.

Design/methodology/approach

A multi-view and all-round vision detection method is introduced where the detection field of view is changing with the vector of the outer surface during the printing process on the six degrees of freedom robot FDM printer.

Findings

After the image is preprocessed, this paper can identify the defects effectively according to its laminate structure, and introduces a mathematical matrix to represent the defects which will be classified into three typical types according to the geometry shape and area distribution.

Research limitations/implications

This research only focuses on the feasibility of the defects detection method. To create the object of high quality, more research is needed to account for the process parameters which significantly cause the defects.

Practical implications

This work will help to detect the defects online, monitor the printing quality of the outer surface, reduce the waste of printed filaments, etc.

Originality/value

This study is among the first to present a multi-view and all-round vision detection method to detect defects on the outer surface in the additive process of FDM; proposes a means of identifying defects according to its laminate structure; and introduces a mathematical matrix to represent the defects which may be used in quality assessment.

Details

Rapid Prototyping Journal, vol. 25 no. 2
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 1 November 2006

Xin Hu and Xi‐bin Cao

To improve the accuracy of mapping of space‐borne three‐line array cameras.

Abstract

Purpose

To improve the accuracy of mapping of space‐borne three‐line array cameras.

Design/methodology/approach

Derivation of the mathematical model and the error model of the three‐line aerial triangulation, the creation of the simulation data, and the analysis and comparison of the simulating result error.

Findings

When using the photographs, which are acquired by adopting the traditional three‐line array cameras, to map without control, there exists the problem that the accuracy cannot satisfy the requirement.

Research limitations/implications

Do not need the ground control points, and can realize the mapping without control. It is of practical application value to the mapping of stars such as the Moon, Mars.

Practical implications

By adding four small matrix CCDs to the traditional three‐line array cameras, and using the effect of the small matrix, controlling the location of the real photograph point, it can improve the accuracy.

Originality/value

Put forward the LMCCD concept of the combination of the three‐linear and the matrix cameras, and validate in theory.

Details

Aircraft Engineering and Aerospace Technology, vol. 78 no. 6
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 1 February 1997

Mike Wilson

Highlights recent developments in laser vision technology with regard to the aerospace industry. Specifically looks at its application to the Ariane 5 rocket, CCD cameras

375

Abstract

Highlights recent developments in laser vision technology with regard to the aerospace industry. Specifically looks at its application to the Ariane 5 rocket, CCD cameras, adhesives and sealants and a sensor which defines the accuracy of drilling and countersinking in airfoil shapes.

Details

Aircraft Engineering and Aerospace Technology, vol. 69 no. 1
Type: Research Article
ISSN: 0002-2667

Keywords

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