Search results

1 – 10 of over 82000
Article
Publication date: 14 May 2024

Yiwen Jiang and Chunyan Zhang

There is coupling between the branches of mobile parallel robots, similar to traditional parallel mechanisms, but there is currently relatively little research on the coupling

Abstract

Purpose

There is coupling between the branches of mobile parallel robots, similar to traditional parallel mechanisms, but there is currently relatively little research on the coupling problem between the branches of mobile parallel robots.

Design/methodology/approach

This study optimizes the coupling analysis method of traditional parallel mechanisms, treats the mobile parallel mechanism as a whole, takes the motion of the active pair as input and the overall motion of the mobile parallel mechanism as output and analyzes the input–output characteristics of the mobile parallel mechanism. Moreover, this study applies this theory to a mobile parallel mechanism, designs control logic and finally conducts simulation and physical verification.

Findings

This study proposes a coupling analysis method suitable for parallel mobile robots and designs the control logic of their active pair based on the results of their coupling analysis. This study designs a multimode variable coupling parallel mobile robot, which can change the coupling of the mechanism by changing its own branch chain structure, so that it can switch between different coupling configurations to meet the different needs brought by different terrains.

Originality/value

The work presented in this paper propose a method for analyzing the coupling of mobile parallel robots and simplify their control logic by applying coupling theory to the design of mobile parallel robots. This study conducts simulation and physical experiments, thereby filling the gap in the coupling analysis of parallel mobile robots and laying the foundation for the research of uncoupled parallel mobile robots.

Details

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

Keywords

Article
Publication date: 8 June 2012

Baohua Yang, Shili Fang and Jinshuai Zhao

The purpose of this paper is to attempt to realize a complete analysis at scenario deduction of unconventional incidents coupling based on the GERTS network method.

Abstract

Purpose

The purpose of this paper is to attempt to realize a complete analysis at scenario deduction of unconventional incidents coupling based on the GERTS network method.

Design/methodology/approach

Starting from the manifestation of coupling objects, three types of emergency coupling are analyzed according to different rules, which are “events‐events” coupling, “event‐factors” coupling and “factors‐factors” coupling. Then the coupling mechanism for emergency is focused on analyzing, and the concepts of three types of coupling are put forward, at the same time, three quantitative models for coupling mechanisms are present. Also, a case was discussed to verify the analysis of coupling mechanism of emergency.

Findings

According to the types of factors rules, the classes of coupling of emergency have been divided into three types. The coupling mechanism of emergency can be used to describe the novel coupling models.

Practical implications

This research provides the method for coupling analysis in the scenario of unconventional incidents and guides the emergency managers to develop contingency strategies.

Originality/value

The paper succeeds in constructing a novel coupling model for emergency, and it could provide an effective tool for a quantitative study on unconventional incidents coupling.

Article
Publication date: 1 December 2002

Brian Rowan

In this paper, I argue that ideas about loose coupling can serve a useful purpose in organization theory, but only if they are re‐worked substantially. This re‐working, I argue…

1269

Abstract

In this paper, I argue that ideas about loose coupling can serve a useful purpose in organization theory, but only if they are re‐worked substantially. This re‐working, I argue, will involve merging ideas about loose coupling with ideas found in other lines of work developed contemporaneously, including research on the “new” managerialism, institutional theory, and organizational ecology. Such a re‐working, I hope, will entail closer attention to the elements in educational systems that can be coupled and to an expanded list of coupling mechanisms. Using this expanded list of coupling mechanisms, and thinking more clearly about how educational organizations are embedded in dense and complex webs of couplings calls for a movement away from an exclusive concern with loose and tight couplings among dyadic elements in organizational systems, and toward a concern with “tangled” couplings.

Details

Journal of Educational Administration, vol. 40 no. 6
Type: Research Article
ISSN: 0957-8234

Keywords

Article
Publication date: 1 October 2018

Yunlong Zhong, Lijian Wu, Youtong Fang and Xiaoyan Huang

The purpose of this paper is to investigate and restrain the cross-coupling effect among X, Y and Z-axes of a three degrees of freedom hybrid magnetic bearing (3-DOF HMB). The…

Abstract

Purpose

The purpose of this paper is to investigate and restrain the cross-coupling effect among X, Y and Z-axes of a three degrees of freedom hybrid magnetic bearing (3-DOF HMB). The influence of the cross-coupling effect on the force characteristics and stiffnesses are analysed. Two additional methods are proposed to eliminate the cross-coupling effect.

Design/methodology/approach

Analysis with finite element method (FEM) is time-consuming because of the requirement of a 3D model for the studied 3-DOF HMB. Hence, an improved magnetic circuit model considering the leakage, cross-coupling and saturation effects is used to investigate the cross-coupling effect in this paper. In addition, two restraining methods are proposed. One is adding an auxiliary coil between radial and axial stators. The other is adding an iron ring between the PM and radial or axial stator.

Findings

The X-axis (or Y-axis) force characteristics and stiffnesses are significantly influenced by the Z-axis current, while other axes force characteristics and stiffnesses do not show the cross-coupling effect. Moreover, this cross-coupling effect is inversely related to the distance between axial thrust disk and radial MB part. Besides, adding an auxiliary coil can effectively eliminate the cross-coupling effect in whole work range and adding an iron ring can reduce the cross-coupling effect.

Originality/value

The cross-coupling effect and its restraining methods of a 3-DOF HMB are investigated, which is beneficial to the design and control of such 3-DOF HMB.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 6 July 2012

Sucheng Liu, Luowei Zhou, Weiguo Lu and Anxin Li

The purpose of this paper is to model and analyze energy transfer through near‐field resonant coupling for high power light‐emitting diode (HPLED) illumination, with the intention…

Abstract

Purpose

The purpose of this paper is to model and analyze energy transfer through near‐field resonant coupling for high power light‐emitting diode (HPLED) illumination, with the intention to increase the appreciation and use of the coupled mode theory (CMT) other than the usual equivalent circuit method.

Design/methodology/approach

The CMT is extensively used to analyze the wireless energy transfer system because of its generality, simplicity, accuracy and intuitive understanding of near‐field resonant energy coupling mechanism.

Findings

The CMT forms a general way to model and analyze the non‐radiative magnetic resonant coupling systems. It is suitable not only for low frequency coupling but also for high frequency (of million‐Hertz) in which the circuit parameters are not easily obtained. Optimal coupling condition corresponding to the maximum power transfer is identified based on the CMT, and the multiple limit cycle phenomenon caused by the nonlinear nature of the HPLED is also described on the CMT model.

Originality/value

This paper takes advantages of CMT, i.e. generality, simplicity, accuracy and intuitive understanding to analyze the near‐field resonant energy coupling system. Key characteristics of the systems are explored based on the CMT, not the usual equivalent circuit method. The influence of nonlinear nature of the high power LED on energy transfer is also investigated. This work seeks a more general way than conventional equivalent circuit method to model and analyze the resonant magnetic system and the results obtained could facilitate better understanding of the resonant magnetic coupling mechanism and optimal design of the near‐field energy transfer system.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 31 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 4 September 2017

Matthias Jüttner, Andreas Pflug, Markus Wick and Wolfgang M. Rucker

Multiphysics problems are solved either with monolithic or segregated approaches. For accomplishing contrary discretisation requirements of the physics, disparate meshes are…

Abstract

Purpose

Multiphysics problems are solved either with monolithic or segregated approaches. For accomplishing contrary discretisation requirements of the physics, disparate meshes are essential. This paper is comparing experimental results of different interpolation methods for a segregated coupling with monolithic approaches, implemented using a global and a local nearest neighbour method. The results show the significant influence of discretisation for multiphysics simulation.

Design/methodology/approach

Applying disparate meshes to the monolithic as well as the segregated calculation of finite element problems and evaluating the related numerical error is content of the contribution. This is done by an experimental evaluation of a source and a material coupling applied to a multiphysics problem. After an introduction to the topic, the evaluated multiphysics model is described based on two bidirectional coupled problems and its finite element representation. Afterwards, the considered methods for approximating the coupling are introduced. Then, the evaluated methods are described and the experimental results are discussed. A summary concludes this work.

Findings

An experimental evaluation of the numerical errors for different multiphysics coupling methods using disparate meshes is presented based on a bidirectional electro-thermal simulation. Different methods approximating the coupling values are introduced and challenges of applying these methods are given. It is also shown, that the approximation of the coupling integrals is expensive. Arguments for applying the different methods to the monolithic and the segregated solution strategies are given and applied on the example. The significant influence of the mesh density within the coupled meshes is shown. Since the projection and the interpolation methods do influence the result, a careful decision is advised.

Originality/value

In this contribution, existing coupling methods are described, applied and compared on their application for coupling disparate meshes within a multiphysics simulation. Knowing their performance is relevant when deciding for a monolithic or a segregated calculation approach with respect to physics dependent contrary discretisation requirements. To the authors’ knowledge, it is the first time these methods are compared with a focus on an application in multiphysics simulations and experimental results are discussed.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 17 April 2024

Bingwei Gao, Hongjian Zhao, Wenlong Han and Shilong Xue

This study proposes a predictive neural network model reference decoupling control method for the coupling problem between the leg joints of hydraulic quadruped robots, and…

Abstract

Purpose

This study proposes a predictive neural network model reference decoupling control method for the coupling problem between the leg joints of hydraulic quadruped robots, and verifies its decoupling effect..

Design/methodology/approach

The machine–hydraulic cross-linking coupling is studied as the coupling behavior of the hydraulically driven quadruped robot, and the mechanical dynamics coupling force of the robot system is controlled as the disturbance force of the hydraulic system through the Jacobian matrix transformation. According to the principle of multivariable decoupling, a prediction-based neural network model reference decoupling control method is proposed; each module of the control algorithm is designed one by one, and the stability of the system is analyzed by the Lyapunov stability theorem.

Findings

The simulation and experimental research on the robot joint decoupling control method is carried out, and the prediction-based neural network model reference decoupling control method is compared with the decoupling control method without any decoupling control method. The results show that taking the coupling effect experiment between the hip joint and knee joint as an example, after using the predictive neural network model reference decoupling control method, the phase lag of the hip joint response line was reduced from 20.3° to 14.8°, the amplitude attenuation was reduced from 1.82% to 0.21%, the maximum error of the knee joint coupling line was reduced from 0.67 mm to 0.16 mm and the coupling effect between the hip joint and knee joint was reduced from 1.9% to 0.48%, achieving good decoupling.

Originality/value

The prediction-based neural network model reference decoupling control method proposed in this paper can use the neural network model to predict the next output of the system according to the input and output. Finally, the weights of the neural network are corrected online according to the predicted output and the given reference output, so that the optimization index of the neural network decoupling controller is extremely small, and the purpose of decoupling control is achieved.

Details

Robotic Intelligence and Automation, vol. 44 no. 2
Type: Research Article
ISSN: 2754-6969

Keywords

Book part
Publication date: 26 October 2012

William Ocasio

This chapter first examines the role of attention in the garbage can model of decision making and compares it both to prior approaches in the Carnegie School tradition and the…

Abstract

This chapter first examines the role of attention in the garbage can model of decision making and compares it both to prior approaches in the Carnegie School tradition and the attention-based view of the firm. Both the garbage can model and the attention-based view rely on the same assumption, one that is rarely recognized nor understood – that organizational decision making is characterized by situated attention, where organizational participants vary across time and place in what they attend to. In the garbage can model, decision opportunities are the temporal contexts for situated attention; in the attention-based view, attention is situated in both time and place within the organization's communication channels. In the garbage can, situated attention is also shaped by the ecology of problems and opportunities competing for attention. The final part examines the determinants and consequences of tight versus loose coupling of channels in organizations and its effects on participants’ situated attention. Attention structures external to channels and the architecture of channel structures shape the degree of coupling found in organizations. In viewing coupling as a variable, the chapter suggests that a modified garbage can model, combined with an increased focus on situated attention, provides the foundations for a more general theory of nonroutine decision making.

Details

The Garbage Can Model of Organizational Choice: Looking Forward at Forty
Type: Book
ISBN: 978-1-78052-713-0

Book part
Publication date: 7 October 2019

Mari Elken and Martina Vukasovic

The term “loose coupling” has been widely employed in higher education research. Building partly on the “garbage can model” of decision-making, it proposed an alternative to…

Abstract

The term “loose coupling” has been widely employed in higher education research. Building partly on the “garbage can model” of decision-making, it proposed an alternative to rational and linear views on organizing and governing, emphasizing instead ambiguity and complexity. The review of higher education research literature presented in this chapter demonstrates that the concept of loose coupling has frequently been used as a background concept, often taken for-granted either as a point of departure for studies of organizational processes in higher education or as a diagnosis of the complexity of higher education organization that inhibits implementation of reforms. This chapter provides systematization and critical examination of how the term “loose coupling”/“loosely coupled systems” has been employed in journal articles focusing on higher education in the last 40 years. It presents a broad mapping of 209 articles and a more detailed qualitative review of 22 articles, which employed loose coupling as more than a background concept.

Details

Theory and Method in Higher Education Research
Type: Book
ISBN: 978-1-83867-842-5

Keywords

Article
Publication date: 22 June 2023

Jingjing Sun, Ziming Zeng, Tingting Li and Shouqiang Sun

The outbreak of COVID-19 has become a major public health emergency worldwide. How to effectively guide public opinion and implement precise prevention and control is a hot topic…

Abstract

Purpose

The outbreak of COVID-19 has become a major public health emergency worldwide. How to effectively guide public opinion and implement precise prevention and control is a hot topic in current research. Mining the spatiotemporal coupling between online public opinion and offline epidemics can provide decision support for the precise management and control of future emergencies.

Design/methodology/approach

This study focuses on analyzing the spatiotemporal coupling relationship between public opinion and the epidemic. First, based on Weibo information and confirmed case information, a field framework is constructed using field theory. Second, SnowNLP is used for sentiment mining and LDA is utilized for topic extraction to analyze the topic evolution and the sentiment evolution of public opinion in each coupling stage. Finally, the spatial model is used to explore the coupling relationship between public opinion and the epidemic in space.

Findings

The findings show that there is a certain coupling between online public opinion sentiment and offline epidemics, with a significant coupling relationship in the time dimension, while there is no remarkable coupling relationship in space. In addition, the core topics of public concern are different at different coupling stages.

Originality/value

This study deeply explores the spatiotemporal coupling relationship between online public opinion and offline epidemics, adding a new research perspective to related research. The result can help the government and relevant departments understand the dynamic development of epidemic events and achieve precise control while mastering the dynamics of online public opinion.

Details

Library Hi Tech, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0737-8831

Keywords

1 – 10 of over 82000