bluuebunny/crossref_metadata_2025_split huggingface dataset:
How to ensure stable motion of suspended wheeled mobile robots
Authors: Alipour Khalil , Moosavian S. Ali A. 
Published: February 2011

PurposeA suspended wheeled mobile robot (SWMR) that consists of one or more manipulators can be exploited in various environmental conditions such as uneven surfaces. The purpose of this paper is to discuss the requirements for stable motion planning of such robotic systems to perform heavy object manipulation tasks.Design/methodology/approachFirst, a systematic procedure for dynamics modelling of such complicated systems for planar motion is presented and verified using ADAMS simulation software. Next, based on the new dynamic moment‐height stability (MHS) measure, the stability of such systems will be investigated using the obtained dynamics. To this end, introducing the concept of a virtual frame, the obtained model of SWMR has been employed for investigating the effect of the base suspension characteristics as well as terrain roughness on the stability of the system. Next, the stability evaluation of the system is investigated after toppling down which has been rarely addressed in the literature. In addition, using the aforementioned model, the effect of stiffness is examined after instability.FindingsFirst, a systematic procedure for dynamics modelling of such complicated systems for planar motion is presented and verified using ADAMS simulation software. Next, based on the new dynamic MHS measure, the stability of such systems will be investigated using the obtained dynamics. To this end, introducing the concept of a virtual frame, the obtained model of SWMR has been employed for investigating the effect of the base suspension characteristics as well as terrain roughness on the stability of the system. Next, the stability evaluation of the system is investigated after toppling down which has been rarely addressed in the literature. In addition, using the aforementioned model, the effect of stiffness is examined after instability.Originality/valueA general procedure for dynamics modelling of SWMRs is presented. To verify the obtained dynamics model, another model for the considered system has been developed by ADAMS software. Next, using the obtained dynamics, the postural stability of such systems is investigated, based on the new postural MHS measure extended for SWMRs. The obtained simulation results show that by decreasing the stiffness coefficients of suspension subsystem the stability of the system weakens.
Human motion capture sensors and analysis in robotics
Authors: Field Matthew , Pan Zengxi , Stirling David , Naghdy Fazel 
Published: February 2011

PurposeThe purpose of this paper is to provide a review of various motion capture technologies and discuss the methods for handling the captured data in applications related to robotics.Design/methodology/approachThe approach taken in the paper is to compare the features and limitations of motion trackers in common use. After introducing the technology, a summary is given of robotic‐related work undertaken with the sensors and the strengths of different approaches in handling the data are discussed. Each comparison is presented in a table. Results from the author's experimentation with an inertial motion capture system are discussed based on clustering and segmentation techniques.FindingsThe trend in methodology is towards stochastic machine learning techniques such as hidden Markov model or Gaussian mixture model, their extensions in hierarchical forms and non‐linear dimension reduction. The resulting empirical models tend to handle uncertainty well and are suitable for incrementally updating models. The challenges in human‐robot interaction today include expanding upon generalising motions to understand motion planning and decisions and build ultimately context aware systems.Originality/valueReviews including descriptions of motion trackers and recent methodologies used in analyzing the data they capture are not very common. Some exist, as has been pointed out in the paper, but this review concentrates more on applications in the robotics field. There is value in regularly surveying the research areas considered in this paper due to the rapid progress in sensors and especially data modeling.
Coordination control of dual‐arm modular robot based on position feedback using Optotrak3020
Authors: Zhou Jun , Yu Yueqing 
Published: February 2011

PurposeThe purpose of this paper is to present a novel and accurate coordination control method of dual‐arm modular robot based on position feedback using 3D motion measurement system – Optotrak3020. The end‐position accuracy of dual‐arm modular robot can be improved obviously.Design/methodology/approachBy means of Optotrak3020, the actual end‐position of dual‐arm modular robot is acquired and then returned to the robotic controllers, so the corresponding position error compensation is implemented. Through a 3D simulation and experiment of dual‐arm modular robot for tracking a trajectory of plane right triangle, the feasibility and validity of this control strategy are verified.FindingsThe coordination control of dual‐arm modular robot based on position feedback can be accomplished by means of Optotrak3020. The dual‐arm modular robot can accurately accomplish the task of positioning or tracking a reference trajectory.Practical implicationsThis real‐time position feedback control method with high control accuracy can be implemented on a PowerCube dual‐arm modular robot system. This method also can be applied to other dual‐arm robot systems, such as mobile robot with dual‐arm, humanoid robot.Originality/valueThe coordination control method of dual‐arm modular robot is presented based on end‐position feedback using Optotrak3020 motion measurement system. The platforms of simulation, communication and experiment are developed, respectively.
Real‐time collision avoidance algorithm for robotic manipulators
Authors: Bosscher Paul , Hedman Daniel 
Published: February 2011

PurposeThe purpose of this paper is to present an algorithm for performing collision avoidance with robotic manipulators.Design/methodology/approachThe method does not require any a priori knowledge of the motion of other objects in its environment. Moreover, it is computationally efficient enough to be implemented in real time. This is achieved by constructing limitations on the motion of a manipulator in terms of its allowable instantaneous velocity. Potential collisions and joint limits are formulated as linear inequality constraints. Selection of the optimal velocity is formulated as a convex optimization and is solved using an interior point method.FindingsExperimental results with two industrial arms verify the effectiveness of the method and illustrate its ability to easily handle many simultaneous potential collisions.Originality/valueThe resulting algorithm allows arbitrary motions commanded to the robot to be modified on‐line in order to guarantee optimal real‐time collision avoidance behaviors.
Reconfiguring the sociology of the crowd: exploring crowdsourcing
Authors: Wexler Mark N. 
Published: February 2011

PurposeThe purpose of this paper is to examine the manner in which advocates of crowdsourcing reconfigure the classical sociological treatment of the crowd.Design/methodology/approachThe approach taken conceives of the semantics of crowd theorizing in three phases, each of which makes sense of the power dynamics between the elite and the crowd. In phases one and two, the crowd is conceptualized as a problem generator; in phase three, the crowd is depicted as a problem solver and innovator.FindingsThis paper provides a critical look at phase three crowd theorizing. It explores how, by ignoring the disruptive power dynamic, crowdsourcing generates a credible image of the crowd as an innovator and problem solver. The work concludes with a discussion of the implications of phase three crowd theorizing for researchers in sociology.Practical implicationsAdvocates of the wisdom of crowds, if interested in the sociological implications of their position, must attend to both the disruptive and costly implications of third phase crowd theorizing.Originality/valueThis paper maps the crowdsourcing process and places it in context. It argues that the distance between the classical social scientific treatment of the crowd is not nearly as great as crowdsourcing advocates would have one believe. Nevertheless, phase three crowd theorizing opens up sociologically relevant questions regarding the future portrayal of collective intelligence as a form of virtual property.
Undocumented worker transitions: family migration
Authors: Paraskevopoulou Anna 
Published: February 2011

PurposeThe purpose of this paper is to discuss family migration through the findings of the undocumented worker transitions (UWT) European Union funded, sixth framework project, which was completed in February 2009.Design/methodology/approachFocusing on results from 211 interviews across seven European countries, together with the current literature on the subject, the paper identifies types of family migration and examines the implications of migration policies and measures in relation to family life and the position of individuals within it, such as women, children or the older people. The paper argues that family‐related reasons often play a central role in the decision to migrate and shape employment experiences.FindingsIndependent of restrictions imposed by various states to control migration, family‐related migration does occur in destinations considered to provide economic prosperity (or survival) with the help of social networks and often with the intention of settling permanently/semi‐permanently in the host state. Status shift towards irregularity often translates to a more vulnerable position in the labour market, inviting exploitation and worsening of the working conditions as a result of precarious employment conditions.Social implicationsThe paper concludes that greater protection (in terms of status) and encouragement (in terms of involvement in the civic society) is needed for migrant families in order to enable integration and combat future disadvantage and discrimination that might be experienced by this group.Originality/valueThe paper places emphasis on irregular migrants, as research in this area is limited. The work is also original as it is based on primary research on the experiences of undocumented migrants in seven European countries.
Festo drives automation forwards
Authors: Wilson Mike 
Published: February 2011

PurposeThe purpose of this paper is to review the latest developments, both in terms of products and manufacturing, of the Festo company.Design/methodology/approachThis paper is a result of a visit made to Festo and also the Motek show in 2010.FindingsFesto is developing new products which will not only enable new applications for automation, but also challenge the traditional approach of applying standard robots or gantries.Originality/valueThe paper provides an overview of the latest Festo developments highlighting their importance.
Petri net versus queuing theory for evaluation of FMS
Authors: Ullah Hamid 
Published: February 2011

PurposePetri net (PN) and queuing theory are used in performance analysis of a flexible manufacturing system (FMS). They are used to determine the FMS measures of performance. These measures of performance include optimal work‐in‐process (WIP), lead time, production rate, machine utilization, and number of servers at each station. The purpose of this paper is to present a comparison between PN and queuing network tools to determine the optimum values for FMS measures of performance.Design/methodology/approachPN model with dual kanban and closed queuing network are used for analysis and performance evaluation of FMS. Integrated network analyzer and Lingo softwares are used for performance evaluation of FMS by PN tool. CANQ software is used for performance evaluation of FMS by queuing network. In both the approaches, the throughput is bounded by the utilization of the bottleneck machines.FindingsThe comparison shows that for the given number of servers, PN gives better values of performance measures for FMS. The PN optimization gives minimum WIP corresponding to the maximum production rate. Minimum WIP leads to minimum lead time.Research limitations/implicationsThe results are concluded based on one case study. In future research, the results may be achieved by doing more case studies with different numbers of system parameters and/or parameter settings.Practical implicationsUsing the PN model, the production manager may design, analyze, evaluate, and even optimize the layout of the production system for minimum WIP, maximum throughput, and reduced lead time. The determination of the total WIP, total number of stations in the production system, and the number of servers at each station may be helpful in shop floor management. It may result in more production efficiency along with ease of supervision.Originality/valueThis paper presents a first novel comparison of its kind between PN and queuing network for evaluation of FMS.
Root cause analysis support for quality improvement in electronics manufacturing
Authors: Huertas‐Quintero L.A.M. , Conway P.P. , Segura‐Velandia D.M. , West A.A. 
Published: February 2011

PurposeThe purpose of this paper is to propose a new software tool to support design for quality (DfQ) in the electronics manufacturing sector where quality and reliability are critical.Design/methodology/approachAn integrated modelling framework that enables complete and realistic representations of manufacturing systems is proposed. A software tool, developed based on this framework, offers two modules to support DfQ: simulation and root cause analysis. This paper focuses on the latter.FindingsIntegrated models enable tracing back effects to their root causes. Software tools based on these, kind of models can provide support in finding and eliminating the cause of a particular effect. This capability can be used to perform DfQ in an effective and accurate way.Research limitations/implicationsThe approach proposed strongly depends on the quality models within the integrated modelling framework. The models currently available are little and simplified. Future work includes the enrichment of the software by developing and more quality models.Practical implicationsThe adoption of the proposed approach in an industrial context requires formalised information to fulfil the data required by the integrated modelling framework.Originality/valueThe main contribution of the paper is the integrated modelling framework definition and its implementation in the form of a software tool. The adoption of this tool in printed circuit assembly companies can support the solution of real quality problems and consequently, help to optimise manufacturing systems in the domain.
A practical method for measuring product maintainability in a virtual environment
Authors: Yu Haiquan , Peng Gaoliang , Liu Wenjian 
Published: February 2011

PurposeAs an important product characteristic, maintainability is recognized as a highly significant factor in the economic success of engineering systems and products. Based on virtual reality technology, this paper aims to create an intuitive, immersive and interactive environment for product maintenance. In order to analyze and evaluate the product maintainability in a virtual maintenance environment, fuzzy comprehensive evaluation is used. At the early design stage, maintainability influencing factors are analyzed and the whole maintainability evaluation of the product is given by using fuzzy comprehensive evaluation method in virtual maintenance environment.Design/methodology/approachThe paper provides a fuzzy comprehensive evaluation method for product maintainability evaluation in virtual environment.FindingsFuzzy comprehensive evaluation is used to evaluate product maintainability in virtual environment, and the application of virtual maintainability system is expanded.Originality/valueAccording to maintainability requirement, the maintainability index set is built in this paper, and fuzzy comprehensive evaluation method is used to evaluate product maintainability in virtual maintenance environment at stage of early design.
A systems approach in the evaluation and comparison of engineering services applied in facilities management
Authors: Halim Tony , Muthusamy Kanesan , Yong Chia Sie , Wei Lam Shao 
Published: February 2011

PurposeThis paper aims to be a balance of mixed management and engineering concepts that aims to fuse classical engineering methodologies into a systems engineering framework to assess and compare systematically and comprehensively services rendered by engineering systems.Design/methodology/approachAn auditing framework is developed to assess the performance of engineering services in the context of engineering services found within a facility. As a result of a system heterogeneity factor, an approach to remove this confounding issue is developed to provide a different insight into the performance of engineering services.FindingsThe output of the audit exercise serves as an input to the second methodology, direct age‐adjusted failure, which overcomes systems attributes confounding issues when comparison is made between different systems populations of the same class type. This method allows management to identify areas in which extra resources are needed to improve maintenance performance.Practical implicationsThe proposed standardization technique, which can be applied to system attributes other than age, overcomes the systems heterogeneity issue between localities. This research work is positioned in the context of building engineering services, as they are the most important in terms of socio‐economical impact. A case study based on an actual facilities assessment in Singapore is used to demonstrate the usefulness of such an integrated systems approach.Originality/valueThis paper presents a qualitative‐quantitative assessment framework that consists of two major methodologies to help in identifying and prioritising engineering system services in order to allocate limited resources to the appropriate engineering service so as to improve its performance.
On the modeling of shear bands formation in J2materials with damage evolution
Authors: D'hers Sebastian , Dvorkin Eduardo N. 
Published: February 2011

PurposeThe purpose of this paper is to model the strain localization in J2materials with damage evolution using embedded strong discontinuity modes.Design/methodology/approachIn this procedure, an heuristic bandwidth scale is adopted to model the damage evolution in the shear bands. The bifurcation triggering conditions and band growth directions are studied for these materials.FindingsThe resulting formulation does not require a specific mesh refinement to model a localization, provides mesh independent results also insensitive to element distortions and allows calibration of the model response using experimental data. The formulation capability is shown embedding the strong discontinuity modes into quadrilateral and higher order elements.Originality/valueThe work described in this paper extends the use of strong discontinuity modes to materials with damage evolution.
Experimental and numerical analysis of blade channel vortices in a Francis turbine runner
Authors: Yexiang Xiao , Zhengwei Wang , Zongguo Yan 
Published: February 2011

PurposeThe purpose of this paper is to investigate, experimentally and numerically, the pressure pulse characteristics and unsteady flow behavior in a Francis turbine runner for moderate flow heads. The pressure pulses in the runner blade passage were predicted numerically for both moderate and high heads. The calculations were used to partition the turbine operating regions and to clarify the various for the unsteady flow behavior, especially the blade channel vortex in the runner.Design/methodology/approachExperimental and numerical analyses of pressure pulse characteristics at moderate flow heads in a Francis turbine runner were then extended to high heads through numerical modeling with 3D unsteady numerical simulations performed for a number of operating conditions. The unsteady Reynolds‐averaged Navier‐Stokes equations with the k‐ω‐based shear stress transport turbulence model were used to model the unsteady flow within the entire flow passage of a Francis turbine.FindingsThe dominate frequency of the predicted pressure pulses at runner inlet agree with the experimental results in the head cover at moderate flow heads. The influence of the blade passing frequency causes the simulated peak‐to‐peak amplitudes in the runner inlet to be larger than in the head cover. The measured and predicted pressure pulses at different positions along the runner are comparable. At the most unstable operating condition of 0.5a0 guide vane opening, the pressure pulses in the runner blade passage are due to the blade channel vortex and the rotor‐stator interference. The predictions show that the frequency of the blade channel vortex is relatively low and it changes with the operating conditions.Originality/valueThe paper describes a study which experimentally and numerically investigated the pressure pulses characteristics in a Francis turbine runner at moderate flow heads. The pulse characteristics and unsteady flow behavior due to the blade channel vortex in the runner at high heads were investigated numerically, with the turbine operating regions then partitioned to identify safe operating regions.
Drivers of change: a contemporary model
Authors: Kirsch Christina , Chelliah John , Parry Warren 
Published: February 2011

PurposeThis paper introduces a contemporary model developed by a Sydney‐based consulting firm, ChangeTracking Research. The model was developed through an initial survey of 146 companies based in 27 countries.Design/methodology/approachThe authors present a change development model which uses Hofstede's work as a foundation for understanding cross‐cultural differences in organizations from across the world and how that affects change management in these cultures. The model is informed by initial surveys of employees from 27 nationalities in 146 companies working in a variety of industries.FindingsThe paper presents a model that identifies six key drivers arising from different cultural dimensions that determine success in change management projects.Practical implicationsThe model developed in this paper introduces new knowledge of the cross‐cultural dynamics in change management projects which would prove useful to change managers throughout the world.Originality/valueThe paper presents a unique model that presents six key drivers that determine the success of change management. A subset of clusters under each driver presents an in‐depth understanding of the critical issues to be recognized and managed in differing cultural contexts.