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Article

Cengiz Deniz and Mustafa Cakir

The purpose of this study is to design a robotic inline measurement system for spot welding quality control to achieve process requirement without any operator during the…

Abstract

Purpose

The purpose of this study is to design a robotic inline measurement system for spot welding quality control to achieve process requirement without any operator during the manufacturing flow.

Design/methodology/approach

A robot manipulator carries a stereo-camera and an ultrasonic control probe. The center position of the spot welding point is determined by evaluating the results of the edge, gradient and symmetry approaches from the methods proposed up to now in the literature to increase reliability. The center position of the spot welding point, determined in the camera reference plane, is transferred to the robot base plane coordinates with the hand–eye calibration proposed in this manuscript. Weld quality is checked by the ultrasonic test probe located at the spot welding point.

Findings

While operators can only control welding quality, the developed station can also evaluate the quality based on geometric accuracy by processing the deviation of the position of the spot welding points. The proposed calibration method and the results of other methods in the literature are presented in this study by comparing it with synthetic data in simulations and in practical application.

Research limitations/implications

The quality control is performed not only for the spot welding made with robots but also for the manual welds as well. Because of vision configuration, and reliability issues, maximum allowable offset by the correct spot position is limited to 20 mm to position the manipulator for testing. The installation and pretest works of the developed robotic welding quality control station are completed in the Body Shop Area of Ford Otosan factory in Kocaeli/Turkey. The results of the robotic control process are monitored by the quality assurance team. Integration of automation with the production line will be completed and an inline measurement will be done.

Originality value

In this paper, a new hand–eye calibration method based on simple and closed-form analytical solutions has been presented. The objective function is defined as reducing the deviation in the point projection, rather than reducing the error in the calibration equation. To increase reliability, combining the results of existing centering algorithms for the detection of the strongly deformed spot welding spot center, although it is normally in a circular form, has been suggested.

Details

Industrial Robot: An International Journal, vol. 45 no. 1
Type: Research Article
ISSN: 0143-991X

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Article

Cengiz Deniz and Mustafa Cakir

This paper aims to introduce a simple hand-eye calibration method that can be easily applied with different objective functions.

Abstract

Purpose

This paper aims to introduce a simple hand-eye calibration method that can be easily applied with different objective functions.

Design/methodology/approach

The hand-eye calibration is solved by using the closed form absolute orientation equations. Instead of processing all samples together, the proposed method goes through all minimal solution sets. Final result is chosen after evaluating the solution set for arbitrary objectives. In this stage, outliers can be excluded optionally if more accuracy is desired.

Findings

The proposed method is very flexible and gives more accurate and convenient results than the existing solutions. The mathematical error expression defined by the calibration equations may not be valid in practice, where especially systematic distortions are present. It is shown in the simulations that the solution which results the least mathematical error in systems may have incorrect, incompatible results in the presence of practical demands.

Research limitations/implications

The performance of the calibration performed with the proposed method is compared with the reference methods in the literature. When the back-projection error is benchmarked, which corresponds to the point repeatability, the proposed approach is considered as the most successful method among all others. Due to its robustness, it is decided to make tooling-sensor calibrations by the recommended method, in the robotic non-destructive testing station in Ford-OTOSAN Kocaeli Plant Body Shop Department.

Originality/value

Arranging the well-known AX = XB calibration equation in quaternion representation as Q_A = Q_x × Q_B × Q_x reveals another common spatial rotation equation. In this way, absolute orientation solution satisfies the hand-eye calibration equations. The proposed solution is not presented in the literature as a standalone hand-eye calibration method, although some researchers drop a hint to the relative formulations.

Details

Industrial Robot: An International Journal, vol. 45 no. 1
Type: Research Article
ISSN: 0143-991X

Keywords

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Article

Mustafa Cakir and Cengiz Deniz

The purpose of this study is to present a novel method for industrial robot TCP (tool center point) calibration. The proposed method offers fully automated robot TCP…

Abstract

Purpose

The purpose of this study is to present a novel method for industrial robot TCP (tool center point) calibration. The proposed method offers fully automated robot TCP calibration within a defined cycle time. The method is applicable for large-scale installations due to its zero cost for each robot.

Design/methodology/approach

Precise and expensive measuring equipment or specially designed reference devices are required for robot calibration. The calibration can be performed by using only one plane plate in this method, and the calibration procedure is defined step by step: the robot moves to the target plane position. Then, the TCP touches the plane and the actual robot configuration is recorded. Then robot moves back into position and the same step is repeated for a new sample. Alternatively, the robot can be stationary and the plane can be moved towards the robot TCP. TCP is calculated by processing the difference of the contact points recorded at different positions. The process is fully automated. No special equipment is used. The calculations are very simple, and the robot controller can easily be realized.

Findings

The conventional manual robot TCP calibration process takes about 15 min and takes more time in case of the high accuracy. The proposed method reduces this time to less than 3 min without operator support. Practical tests have shown that TCP calibration can be performed with 0.1-0.6 mm of accuracy. This solution is an automated process and does not require special installation and it also has approximately zero cost. For this reason, this study recommends using the proposed solution widely in areas where even one or hundreds of robots are located.

Research limitations/implications

In this study, the data were directly taken from the robot controller without using any special measuring equipment. The industrial robot used in the tests has no absolute calibration. The classical “four-point method” was used for reference TCP data. It is the initial acceptance that this process conducted with extreme care and by using a needle-tipped tool will not produce exact values. It was observed that deviation of the TCP from a fixed point in reorient motions was not more than 0.5 mm. This method has been validated for different bits. The pilot works for different robot applications in Ford Otosan Gölcük Plant have been completed and dissemination has started.

Originality/value

Although the approach uses is clear and simple, it is surprising that the calculation of TCP using plane equations has so far not been mentioned in the literature. The disadvantage of using either fixed point or sphere as a reference is that the TCP cannot automatically guide to the target. This problem was overcome with the use of a larger target plane plate and the process was fully automated. The proposed method can be widely used in practical applications.

Details

Industrial Robot: the international journal of robotics research and application, vol. 46 no. 5
Type: Research Article
ISSN: 0143-991X

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Article

Emrah Uysal, Mustafa Çakir and Bülent Ekici

Traditional nanocomposite production methods such as in situ polymerization, melt blending and solvent technique, have some deficits. Some of these are non-homogeneous…

Abstract

Purpose

Traditional nanocomposite production methods such as in situ polymerization, melt blending and solvent technique, have some deficits. Some of these are non-homogeneous particle distribution, setup difficulties, time-consuming and costly. On the other hand, three-dimensional printing technology is a quite popular method. Especially, Stereolithography (SLA) printing offers some benefits such as fast printing, easy setup and smooth surface specialties. Furthermore, surface modification of Graphene Oxide (GO) and its effects on polymer nanocomposites are quite important. The purpose of this study is to examine the effect of surface modification of GO nanoparticles on the mechanical properties and morphology of epoxy acrylate (BisGMA/1,6 hexane diol diacrylate) matrix nanocomposites.

Design/methodology/approach

In this study, Ultraviolet (UV) curable end groups of synthesized resin were linked to functional groups of graphene oxide, which are synthesized by the Tour method, which is a kind of modified Hummer method. In addition, synthesized GO nanoparticle’s surfaces were modified by 3-(methacryloyloxy) propyl trimethoxysilane. Significant weight percentages of GO were added into the epoxy acrylate resin. Different Wt.% of modified graphene oxide/acrylate resins was used to print test specimens with SLA type three-dimensional printer.

Findings

Surface modification has a significant effect on tensile strength for graphene oxide nanoparticles contained composites. In addition, a specific trend was not observed for tensile test results of non-modified graphene oxide. The tendency of impact and hardness test finding were similar for both surfaces modified and non-modified nanoparticles. Finally, the distribution of particles was homogeneous.

Originality/value

This paper is unique because of the inclusion of both surface modifications of graphene oxide nanoparticles and SLA production of nanocomposites with its own production of three-dimensional printer and photocurable polymer resin.

Details

Rapid Prototyping Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1355-2546

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Abstract

Details

Marketing Management in Turkey
Type: Book
ISBN: 978-1-78714-558-0

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Book part

Evren Savcı

Departing from Turkish national debates around Islam, national belonging, and homosexuality during 2008–2011, this paper shows how “LGBT rights” discourses ultimately…

Abstract

Departing from Turkish national debates around Islam, national belonging, and homosexuality during 2008–2011, this paper shows how “LGBT rights” discourses ultimately worked to position Muslim headscarf activists as against LGBT activists by rendering complex positions that do not follow easy “for vs. against” LGBT rights political formulas as “homophobic.” In return, this foreclosed potential solidarities differently injured citizens could have formed against increasing neoliberal state violence. I show that the multitude of Muslim women’s positions on the issue of LGBT rights complicates easy religious/secular binaries and illuminates how it is not only human rights discourses but also their “Western” critiques that travel transnationally. This story also contributes to current debates on postsecularism by illustrating how the same national context can house both liberal rights frameworks that can be used against pious Muslim subjects, and a monopolization of a definition of Islam for state power. Finally, I offer “politics of cruelty” and “right to sin” as alternative frameworks for imagining social justice outside of liberal rights-based politics.

Details

Perverse Politics? Feminism, Anti-Imperialism, Multiplicity
Type: Book
ISBN: 978-1-78635-074-9

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Book part

Eda Aylin Genc and Metehan Igneci

The introduction of consumer products can be traced back to the invention of the wheel, and after the first invention, humankind discovered that what can be consumable is…

Abstract

The introduction of consumer products can be traced back to the invention of the wheel, and after the first invention, humankind discovered that what can be consumable is marketable. Therefore, it is safe to suggest that the development of marketing, in thought and practice, has always been hand-in-hand with the evolution of humankind. Modern Turkey or Anatolia, one of the cradles of civilisation located in the Fertile Crescent or, in other words, Old Mesopotamia, has always been the centre of trade and marketing. As an emerging economy, Turkey has a lot to combine the ways of western practices with market dynamics unique to her, whereas authors find the development of marketing practices in Turkey exceptionally interesting. Therefore, this chapter aims to provide an insight and a brief history regarding the development of the Turkish marketing context throughout the years. We believe that this contribution will be helpful to those who are interested in the development of marketing in an emerging economy in an academic fashion, as well as for those who are attracted to follow the footprints of the modern era’s business environment.

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Book part

Nilufer Narli

The EU harmonisation has created changes in the military's formal and informal influence in the directions of decreased formal and informal military influence in civilian…

Abstract

The EU harmonisation has created changes in the military's formal and informal influence in the directions of decreased formal and informal military influence in civilian politics. The EU reforms have created changes in the mindset of the citizens, by creating changes in the security culture of the citizens and in the civil-military related political culture. The desired level of alignment has not been reached. Therefore, the study examines the areas where further alignment is required. Moving from Rebecca L. Schiff's concordance theory, the article examines the relationship between the Turkish military, the civilian politics and the society before and after the EU harmonisation process. It examines the effects of the EU harmonisation process on the changes in the civil-military balance of power, and on the related security culture and political values. The analysis focuses on: (i) increased civilian control and consequent changes in the policy of accountability; (ii) transparency building in the defence sector; (iii) parliamentary oversight; and (iv) the change in the political culture related to the civil-military issues. It also investigates the extent the EU harmonisation has achieved in building democratic civil-military relations in order to align with the EU standards.

Details

Advances in Military Sociology: Essays in Honor of Charles C. Moskos
Type: Book
ISBN: 978-1-84855-893-9

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Article

Sonali Udeeka Pathiratne, Ali Khatibi and Md Gapar Md Johar

This paper aims to identify and review the critical success factors (CSFs) for successful Six Sigma implementation in service and manufacturing companies given in…

Abstract

Purpose

This paper aims to identify and review the critical success factors (CSFs) for successful Six Sigma implementation in service and manufacturing companies given in published literature.

Design/methodology/approach

A descriptive evaluation of the literature body is followed by future research opportunities. Studies published on the topic of Six Sigma during 2005-2016 are reviewed to retrieve identified CSFs.

Findings

From published literature, 48 CSFs vital for Six Sigma implementation were identified. The identified CSFs were classified under eight core categories. As per the categorization, 35 out of 48 CSFs identified are either Company Strategy related, Six Sigma Project related or Human Resources related. Only a limited number of studies are carried out mainly focusing on the stated three core areas. Hence, it is vital that these three core areas are further explored in future research.

Originality/value

With the outcome of this paper, the identified CSFs for Six Sigma will be taken for further studies, where they will be applied to service and manufacturing companies based in Sri Lanka. Hence, it would provide Sri Lankan service and manufacturing companies guidelines for successful implementation of Six Sigma for future endeavors.

Details

International Journal of Lean Six Sigma, vol. 9 no. 4
Type: Research Article
ISSN: 2040-4166

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Article

A. Cansu Gök-Kısa, Pelin Çeli̇k and İskender Peker

Ports are the key elements of maritime transportation, which is crucial for world trade. Approximately 180 port facilities are located in Turkey. After 2007, 5 of the…

Abstract

Purpose

Ports are the key elements of maritime transportation, which is crucial for world trade. Approximately 180 port facilities are located in Turkey. After 2007, 5 of the ports, which are formerly owned by Turkish Republic Railways Administration (TRRA), are privatized. The aim of the study is to evaluate the performance of these privatized ports by multi-criteria decision-making (MCDM) approach.

Design/methodology/approach

The application process is performed by a MCDM model. This model includes both criteria (dry bulk, liquid bulk, general cargo, container, RO-RO capacity, total port area, total berth, total berths length and depth) and alternatives (Mersin, Samsun, Bandirma, Iskenderun and Derince Ports). It determines the weights of the criteria by entropy and ranks the alternatives by ARAS and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) methods.

Findings

The results of entropy, ARAS and TOPSIS methods are compared. According to these results, “container” is the most important criteria while Mersin port has the best performance.

Originality/value

In the literature, most of the studies about this subject were analyzed by data envelopment analysis (DEA) and there are no studies had been taken into consideration ports that are owned by TRRA, in Turkey. Moreover, few of these studies used integrated MCDM models, and this is the first study that integrates entropy, ARAS and TOPSIS methods in this field.

Details

Benchmarking: An International Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1463-5771

Keywords

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