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1 – 10 of 911Erman Şentürk, Safa Bozkurt Coşkun and Mehmet Tarık Atay
The purpose of the study is to obtain an analytical approximate solution for jamming transition problem (JTP) using Adomian decomposition method (ADM).
Abstract
Purpose
The purpose of the study is to obtain an analytical approximate solution for jamming transition problem (JTP) using Adomian decomposition method (ADM).
Design/methodology/approach
In this study, the jamming transition is presented as a result of spontaneous deviations of headway and velocity that is caused by the acceleration/breaking rate to be higher than the critical value. Dissipative dynamics of traffic flow can be represented within the framework of the Lorenz scheme based on the car-following model in the one-lane highway. Through this paper, an analytical approximation for the solution is calculated via ADM that leads to a solution for headway deviation as a function of time.
Findings
A highly nonlinear differential equation having no exact solution due to JTP is considered and headway deviation is obtained implementing a number of different initial conditions. The results are discussed and compared with the available data in the literature and numerical solutions obtained from a built-in numerical function of the mathematical software used in the study. The advantage of using ADM for the problem is presented in the study and discussed on the basis of the results produced by the applied method.
Originality/value
This is the first study to apply ADM to JTP.
Details
Keywords
This paper aims to propose a soft actuator that combines a sponge-based actuating structure and a layer-jamming-based stiffness-improving structure in a cavity.
Abstract
Purpose
This paper aims to propose a soft actuator that combines a sponge-based actuating structure and a layer-jamming-based stiffness-improving structure in a cavity.
Design/methodology/approach
The proposed soft actuator consists of film-constrained sponge units (FCSUs) and jamming layers. The FCSUs in the proposed soft actuator bend under vacuum pressure, causing bending deformation of the entire actuator. The jamming layers are strongly coupled through friction under vacuum pressure, increasing the stiffness of the entire actuator. The performance of the proposed soft actuator was examined by measuring its stiffness, bending deformation and response performance. A four-finger soft robotic gripper was proposed based on the proposed soft actuator.
Findings
Through experiments, it was shown that the proposed soft actuator exhibited acceptable bending deformation, stiffness and response. Moreover, the proposed four-finger soft gripper could effectively grasp objects in daily life.
Originality/value
In this study, the authors proposed a novel bending actuator (with a volume of approximately 43.2 cm3) based on FCSUs and jamming layers. To the best of the authors’ knowledge, this is the first study to combine a sponge-based actuating structure and a layer-jamming structure in a cavity to achieve simultaneous change in actuation and stiffness. The soft actuator exhibited good bending deformation and high stiffness simultaneously under vacuum pressure. Consequently, it could be used effectively to fabricate soft grippers.
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Keywords
Hongtai Cheng, Tianzhuo Liu, Wei Zhang and Lina Hao
Installing a tight tolerant stepped shaft is not a trivial task for an industrial robot. If all peg-hole constraints are complete, the cascaded peg-in-hole task can be simplified…
Abstract
Purpose
Installing a tight tolerant stepped shaft is not a trivial task for an industrial robot. If all peg-hole constraints are complete, the cascaded peg-in-hole task can be simplified into several independent stages and accomplished one by one. However, if some of the constraints are incomplete, the cross stage interference will bring additional difficulties. This paper aims to discuss the cascaded peg-in-hole problem with incomplete constraints.
Design/methodology/approach
In this paper, the problem is formulated according to geometric parameters of the stepped shaft and completeness of the corresponding hole. The possible jamming type is modeled and analyzed. A contact modeling and control strategy is proposed to compensate the peg postures under incomplete constraints.
Findings
The above methods are implemented on an experiment platform and the results verify the effectiveness of the proposed robotic assembly strategy.
Originality/value
Based on force/torque sensor, a hybrid control strategy for incomplete constraints cascaded peg-in-hole assembly problem is proposed.
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Keywords
Yasser Hassan and Eiichiro Tazaki
The aim is identifying and analyzing some well‐defined types of emergence where the paper uses ideas from machine learning and artificial intelligence to provide the model of…
Abstract
Purpose
The aim is identifying and analyzing some well‐defined types of emergence where the paper uses ideas from machine learning and artificial intelligence to provide the model of cellular automata based on rough set theory and response in simulated cars.
Design/methodology/approach
This paper proposes, as practical part, a road traffic system based on two‐dimensional cellular automata combined with rough set theory to model the flow and jamming that is suitable to an urban environment.
Findings
The automaton mimics realistic traffic rules that apply in everyday experience.
Research limitations/implications
The modeled development process in this paper involves simulated processes of evolution, learning and self‐organization.
Practical implications
Recently, the examination and modeling of vehicular traffic has become an important subject of research.
Originality/value
The main value of the model is that it provides an illustration of how simple learning processes may lead to the formation of the state machine behavior, which can give an emergent to the model.
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Keywords
To offer a framework of structural and contextual influences on knowledge transfer of foreign management ideas to Vietnamese academic and managerial colleagues. It addresses four…
Abstract
Purpose
To offer a framework of structural and contextual influences on knowledge transfer of foreign management ideas to Vietnamese academic and managerial colleagues. It addresses four factors: stage of relationship between Vietnamese and foreign counterparts; participative competence (i.e. knowledge, experience, and motivations of those sending and receiving knowledge); atmosphere within each side's organization; and conduit conditions, or factors that facilitate transmittal or translation of knowledge.
Design/methodology/approach
The paper draws on an ethnographic study from 1994‐2003 of the creation of Vietnam's first international standard business school, within the National Economics University (NEU), in Hanoi, which included participant observation, semi‐structured and informal interviews with over 60 Vietnamese faculty members, managers, university administrators, and foreign visiting professors and administrators, field notes, documentation, and archival records.
Findings
The paper concludes that long‐lasting knowledge transfer is not straightforward in its flow; must be bi‐directional for the primary transfer (i.e. of Western business knowledge) to succeed, and moves from primarily explicit to both explicit and more tacit knowledge transfer.
Research limitations/implications
The paper calls for additional research on perceptive competence, organizational atmosphere, conduit conditions, and turning points in relationships.
Practical implications
A toolkit for managers on key aspects to consider in knowledge transfer and exchange within developing countries and within multinational firms.
Originality/value
The paper expands existing models and adds new components regarding the relationship between parties, and the notion of bi‐directional interactions.
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Chuanqi Liu, Qicheng Sun and Guohua Zhang
Granular materials possess multiscale structures, i.e. micro-scales involving atoms and molecules in a solid particle, meso-scales involving individual particles and their…
Abstract
Purpose
Granular materials possess multiscale structures, i.e. micro-scales involving atoms and molecules in a solid particle, meso-scales involving individual particles and their correlated structure, and macroscopic assembly. Strong and abundant dissipations are exhibited due to mesoscopic unsteady motion of individual grains, and evolution of underlying structures (e.g. force chains, vortex, etc.), which defines the key differences between granular materials and ordinary objects. The purpose of this paper is to introduce the major studies have been conducted in recent two decades.
Design/methodology/approach
The main properties at individual scale are introduced, including the coordination number, pair-correlation function, force and mean stress distribution functions, and the dynamic correlation function. The relationship between meso- and macro-scales is analyzed, such as between contact force and stress, the elastic modulus, and bulk friction in granular flows. At macroscales, conventional engineering models (i.e. elasto-plastic and hypo-plastic ones) are introduced. In particular, the so-called granular hydrodynamics theory, derived from thermodynamics principles, is explained.
Findings
On the basis of recent study the authors conducted, the multiscales (both spatial and temporal) in granular materials are first explained, and a multiscale framework is presented for the mechanics of granular materials.
Originality/value
It would provide a paramount view on the multiscale studies of granular materials.
Details
Keywords
Reham Tarek Alnounou, Rawan Ahmed Asiri, Sara Ayman Alhindi, Layan Marwan Shams, Sadia Samar Ali and Eren Özceylan
Saudi Arabia's 2030 vision targets an increase of 34% in non-oil revenue participation in the GDP, thus the need for automation and digital transformation. The Company ER is a…
Abstract
Purpose
Saudi Arabia's 2030 vision targets an increase of 34% in non-oil revenue participation in the GDP, thus the need for automation and digital transformation. The Company ER is a market leader producing high-quality dairy products in the Kingdom and is a pioneer in the production industry. The company has recently increased the capacity of its milk factory to meet its vision. An investment was made to automate the pallet handling procedures at the milk factory to provide increased production for daily consumption. The new automation transition in Company ER's milk factory provides a unique opportunity to utilize lean management tools to improve the current automated processes before commercialization.
Design/methodology/approach
OEE (overall equipment effectiveness) will monitor losses for different operational losses in the new automated system and indicate system improvements, with 85% as the target. Based on DMADV (design, measure, analyze, design and validate) methodology, this study analyzes the entire automated pallet handling system. It uses lean tools to identify areas for improvement, identify waste elements and propose solutions to achieve Company ER's OEE targets.
Findings
In this paper, the outcomes will be presented as documented solutions that address the losses encountered in the production system, showing a 12.8% increase in the system's OEE.
Research limitations/implications
Owing the time and resource constraint, this study only involved automated pallet handling procedures in a milk production facility. Hence, the generalization of the result is slightly limited. More studies in several different processes and sectors are required.
Practical implications
This study provided a valuable tool for researchers for gaining deeper understanding regarding the lean manufacturing and its implementation. For practitioners, it is useful to evaluate the degree of lean manufacturing tools in their material handling systems.
Originality/value
This study is the first attempt to develop lean manufacturing constructs for evaluating the automated pallet handling procedures in a milk production facility.
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Keywords
Michael V. Vartanov, Leonarda V. Bojkova and Inna N. Zinina
The purpose of this paper is to define the conditions for a failsafe coupling of parts when using adaptation and low-frequency vibrations. A model enables us to determine the…
Abstract
Purpose
The purpose of this paper is to define the conditions for a failsafe coupling of parts when using adaptation and low-frequency vibrations. A model enables us to determine the reaction at the contact points of parts and time-based contact conditions changes. Therefore, the conditions of jamming parts can be defined in the process of conjugation.
Design/methodology/approach
A mathematical model describing the trajectory of the part mass center in robotic assembly is created. An experimental equipment is also presented in the paper. Convergence of theoretical and experimental results that characterize the reliability of processes is estimated.
Findings
The mathematical model of the connection process dynamics is found in the form of Lagrange’s equations of the second kind.
Originality/value
Applying low-frequency vibration and the adaptive gripper is proposed to extend technological capabilities of robotic assembly.
Details