Cooperation of robotic manipulators using non‐model‐based multiple impedance control

2008 ◽  
Vol 35 (6) ◽  
pp. 549-558 ◽  
Author(s):  
S. Ali A. Moosavian ◽  
Hadi R. Ashtiani
Keyword(s):  
Error Analysis ◽  
Impedance Control ◽  
Object Manipulation ◽  
Tracking Performance ◽  
Content Type ◽  
Model Based ◽  
On Line ◽  
Cooperating Manipulators ◽  
Manipulation Task ◽  
Practical Implications

PurposeThe aim of this paper is to present the non‐model‐based multiple impedance control (NMIC) law for object manipulation tasks, which can be implemented with reasonable limited on‐line computations.Design/methodology/approachThe multiple impedance control (MIC) is a model‐based algorithm that enforces a designated impedance on all cooperating manipulators, and the manipulated object itself. In this paper, the MIC law is modified to be implemented without using system dynamics. Therefore, this modified MIC law is a quick and more realistic algorithm for implementation in cooperating robotic systems, and so is called NMIC. Developing the NMIC law, error analysis shows that under the NMIC law all participating manipulators, and the manipulated object exhibit the same designated impedance behavior. Next, the proposed NMIC law is applied on an object manipulation task with three cooperating PUMA 560 manipulators while two of them are equipped with a remote compliant centre.FindingsDeveloping the NMIC law, error analysis shows that under the NMIC law all participating manipulators, and the manipulated object exhibit the same designated impedance behavior. The obtained results show good tracking performance even in the presence of impacts due to contact with an obstacle, and also system flexibility.Practical implicationsThe obtained results show good tracking performance even in the presence of impacts due to contact with an obstacle, and also system flexibility. These results reveal the merits of NMIC law as a non‐model‐based algorithm for object manipulation tasks, which can be implemented with reasonable limited on‐line computations.Originality/valueThe proposed NMIC law is applied on an object manipulation task with three cooperating PUMA 560 manipulators while two of them are equipped with a remote compliant centre.

Which impedance strategy is the most effective for cooperative object manipulation?

2017 ◽  
Vol 44 (2) ◽  
pp. 198-209 ◽  
Author(s):  
Payam Zarafshan ◽  
Reza Larimi ◽  
S. Ali A. Moosavian ◽  
Bruno Siciliano
Keyword(s):  
Conceptual Model ◽  
Degrees Of Freedom ◽  
Impedance Control ◽  
Object Manipulation ◽  
Robotic System ◽  
Control Algorithms ◽  
Practical Implementation ◽  
Content Type ◽  
Manipulation Task ◽  
Cooperative Object Manipulation

Purpose The purpose of this paper is to present a comparison study of cooperative object manipulation control algorithms. To this end, a full comprehensive survey of the existing control algorithms in this field is presented. Design/methodology/approach Cooperative manipulation occurs when manipulators are mechanically coupled to the object being manipulated, and the manipulators may not be treated as an isolated system. The most important and basic impedance control (IC) strategies for an assumed cooperative object manipulation task are the Augmented Object Model (AOM) control and the multiple impedance control (MIC) which are found based on the IC, where the former is designed based on the object movement, and the latter is designed based on the whole robot movement. Thus, the basis of these two algorithms are fully studied. Findings The results are fully analyzed, and it is practically verified that the MIC algorithm has the better performance. In fact, the results reveal that the MIC system could successfully perform the object manipulation task, as opposed to the AOM controller: for the same controller gains, the MIC strategy showed better performance than the AOM strategy. This means that because there is no control on the robot base with the AOM algorithm, the object manipulation task cannot be satisfactorily performed whenever the desired path is not within the robot work space. On the other hand, with the MIC algorithm, satisfactory object manipulation is achieved for a mobile robotic system in which the robot base, the manipulator endpoints and the manipulated object shall be moved. Practical implications A simple conceptual model for cooperative object manipulation is considered, and a suitable setup is designed for practical implementation of the two ICs. Originality/value The basis of these two aspects or these two algorithms is fully studied and compared which is the foundation of this paper. For this purpose, a case study is considered, in which a space free-flying robotic system, which contains two 2-degrees of freedom planar cooperative manipulators, is simulated to manipulate an object using the above control strategies. The system also includes a rotating antenna and camera as its third and fourth arm. Finally, a simple conceptual model for cooperative object manipulation is considered, and a suitable setup is designed for practical implementation of the two ICs.

Viscoelastic model based bilateral teleoperation for robotic-assisted tele-palpation

2017 ◽  
Vol 37 (3) ◽  
pp. 322-334 ◽  
Author(s):  
Jing Guo ◽  
Ping Li ◽  
Huaicheng Yan ◽  
Hongliang Ren
Keyword(s):  
Time Delay ◽  
Soft Tissue ◽  
Viscoelastic Model ◽  
Tracking Performance ◽  
Bilateral Teleoperation ◽  
Content Type ◽  
Robotic Assisted ◽  
Model Based ◽  
Varying Time Delay ◽  
On Line

Purpose The purpose of this paper is to design a model-based bilateral teleoperation method to improve the feedback force and velocity/position tracking for robotic-assisted tasks (such as palpation, etc.) under constant and/or varying time delay with environment dynamic property. Time delay existing in bilateral teleoperation easily destabilizes the system. Proper control strategies are able to make the system stable, but at the cost of compromised performance. Model-based bilateral teleoperation is designed to achieve enhanced performance of this time-delayed system, but an accurate model is required. Design/methodology/approach Viscoelastic model has been used to describe the robot tool-soft tissue interaction behavior. Kevin-Boltzmann (K-B) model is selected to model the soft tissue behavior due to its good accuracy, transient and linearity properties among several viscoelastic models. In this work, the K-B model is designed at the master side to generate a virtual environment of remote robotic tool-soft tissue interaction. In order to obtain improved performance, a self perturbing recursive least square (SPRLS) algorithm is developed to on-line update the necessary parameters of the environment with varying dynamics. Findings With fast and optimal on-line estimation of primary parameters of the K-B model, the reflected force of the model-based bilateral teleoperation at the master side is improved as well as the position/velocity tracking performance. This model-based design in the bilateral teleoperation avoids the stability issue caused by time delay in the communication channel since the exchanged information become position/velocity and estimated parameters of the used model. Even facing with big and varying time delay, the system keeps stably and enhanced tracking performance. Besides, the fast convergence of the SPRLS algorithm helps to track the time-varying dynamic of the environment, which satisfies the surgical applications as the soft tissue properties usually are not static. Originality/value The originality of this work lies in that an enhanced perception of bilateral teleoperation structure under constant/varying time delay that benefits robotic assisted tele-palpation (time varying environment dynamic) tasks is developed. With SPRLS algorithm to on-line estimate the main parameters of environment, the feedback perception of system can be enhanced with stable velocity/position tracking. The superior velocity/position and force tracking performance of the developed method makes it possible for future robotic-assisted tasks with long-distance communication.

A model of mobile technologies acceptance for knowledge transfer by employees

2017 ◽  
Vol 21 (5) ◽  
pp. 1053-1076 ◽  
Author(s):  
Michal Kuciapski
Keyword(s):  
Knowledge Management ◽  
Knowledge Transfer ◽  
Conceptual Model ◽  
Mobile Devices ◽  
Mobile Technologies ◽  
Intention To Use ◽  
Content Type ◽  
Model Based ◽  
New Variables ◽  
Practical Implications

Purpose Although mobile devices are ubiquitous among employees, their awareness and readiness to use mobile technologies for competence development is still not widespread and therefore requires further exploration. The purpose of this study is to propose a conceptual model based on the unified theory of acceptance and use of technology (UTAUT) to explain the determinants that affect employees’ intention to use mobile devices and software for knowledge transfer during the process of knowledge management. Design/methodology/approach A conceptual model based on the UTAUT with new variables concerning relative usability (RU) and user autonomy (UA) and new connections between the determinants was developed as a result of a subject matter literature review. A structural equation modelling approach was used to validate the model on the basis of data collected via a survey collected from 371 employees from 21 sectors, both public and private. Findings The UTAUT model extended by new variables like RU and UA explains employee acceptance of mobile technologies for knowledge transfer reasonably well. New proposed variables highlighted that the usability of technology compared to other solutions and user autonomy in the selection and the use of applications have the strongest impact on the employees’ intention to use mobile devices and software for knowledge transfer. Research limitations/implications This model explains the 55 per cent behavioral intention of employees to use mobile technologies for knowledge transfer. Even though it is quite high in terms of acceptance theories, some new variables should be explored. Furthermore, study does not verify whether m-learning acceptance for knowledge transfer is sector-specific. Practical implications Mobile technologies used for knowledge transfer by employees should allow for high UA through their ability to select solutions that they find convenient, use of preferred platforms, personalize applications and utilize devices and software in various environments. They should not be simplified and should have the same functionality and efficiency of use as alternative solutions like web and desktop applications, even if additional effort to learn them would be required. Mobile technologies that take into account UA and RU support the process of employees capturing, distributing and effectively using knowledge. Originality/value The elaborated model provides a valuable solution with practical implications for increasing mobile technologies acceptance for knowledge transfer. The study results contribute both to knowledge management and technology acceptance research fields by introducing two new determinants for the acceptance of technologies in knowledge transfer, such as UA and RU with several additional connections between existing UTAUT variables.

Faculty/staff perceptions of a free campus fitness facility

2014 ◽  
Vol 7 (3) ◽  
pp. 156-170 ◽  
Author(s):  
Theresa C. Brown ◽  
Jennifer Volberding ◽  
Timothy Baghurst ◽  
John Sellers
Keyword(s):  
Motivational Climate ◽  
Self Report ◽  
Staff Perceptions ◽  
Content Type ◽  
Fitness Facility ◽  
Barriers To Exercise ◽  
On Line ◽  
Southern University ◽  
Practical Implications ◽  
Support Facility

Purpose – The purpose of this paper is to determine the reason for faculty and staff (N=657; 35 percent males; M age=45.20) at a large Southern university, for either using or not using the free fitness facilities on campus. Design/methodology/approach – Participants identified themselves as either current (n=306), former (n=213), or never-users (n=138) of the facilities, and completed an on-line self-report qualitative questionnaire asking them to describe their reasons for using or not using the campus fitness facilities. Findings – Thematic coding revealed that motives fell into three broad categories for all user types: personal (i.e. cost, location, social support), facility-specific (i.e. quality and amount of equipment, class variety, hours of operation), and motivational climate (i.e. feeling valued, welcomed, best effort was emphasized). Current users highlighted positive aspects of each category whereas former and never users described each category as a barrier to their exercise routines. Practical implications – The identified themes offer campus administration specific suggestions to entice more non-users and former-users to exercise in the fitness facilities available on campus. Originality/value – While researchers have considered barriers to exercise in past studies, the barriers identified were not specific to fitness facilities. The current work not only examines individuals’ reasons for choosing or not choosing a campus fitness facility for their exercise, but also compares the perspectives of former- and never-users to current-users.

An equivalent stress method to account for local buckling in beam finite elements subjected to fire

2019 ◽  
Vol 10 (3) ◽  
pp. 340-353 ◽  
Author(s):  
Chrysanthos Maraveas ◽  
Thomas Gernay ◽  
Jean-Marc Franssen
Keyword(s):  
Finite Elements ◽  
Constitutive Model ◽  
Yield Stress ◽  
Equivalent Stress ◽  
Local Buckling ◽  
Bernoulli Beam ◽  
Content Type ◽  
Model Based ◽  
Proposed Model ◽  
Practical Implications

Purpose The purpose of this paper is to present an improved temperature-dependent constitutive model for steel that accounts for local instabilities of slender plates using an effective stress-based method. This model can be easily implemented for use with Bernoulli beam finite elements (FEs) in the fire situation. Design/methodology/approach The constitutive model is derived by calibration on parametric numerical analysis on isolated plates subject to buckling at different elevated temperatures. The model is implemented in the FE software SAFIR and validation is performed against experimental and shell element analysis results. Findings A constitutive model based on an equivalent stress method is proposed as an efficient way to consider local buckling in steel members exposed to fire. The proposed stress–strain–temperature relationship is asymmetric and is modified in compression only, by reducing the proportional limit, the yield stress and the strain at yield stress. The reduction of these parameters depends on the plate’s boundary conditions, slenderness and temperature. The validation of the proposed model shows good agreement over a range of profile dimensions, temperatures and steel grades. Research limitations/implications The model is still giving conservative results for large compressive load eccentricities. An enhanced model is under development to improve the predictive capability under large eccentricities. Practical implications The proposed model, easily implemented into any finite element software, allows using fibre type (Bernoulli) beam FEs for modelling structures made of slender sections. This has major practical implications as beam elements are the workhorse used for simulating the behaviour of structures in fire. This model, thus makes it possible to simulate large structures with slender steel sections at a limited computational cost. Originality/value The paper presents a novel steel constitutive model based on an innovative approach to capture local buckling at the material level using an equivalent stress approach. The theoretical development, validation and perspectives for future improvements are presented.

SRI’s turnaround: how four principles guided high-value, market-creating innovation

2017 ◽  
Vol 45 (4) ◽  
pp. 3-8
Author(s):  
Steve Denning
Keyword(s):  
Business Model ◽  
Customer Value ◽  
Large Scale ◽  
Leadership Strategies ◽  
Content Type ◽  
Value Propositions ◽  
On Line ◽  
Market Needs ◽  
Working Hypotheses ◽  
Practical Implications

Purpose The article explores the leadership strategies of a CEO who defied the odds against culture change and accomplished a storied turnaround, Curt Carlson who introduced a culture of innovation at SRI International. Design/methodology/approach Under Carlson’s leadership, SRI developed a methodology for rapid, large-scale, serial innovation, starting with a focus on important customer and market needs. The innovation proposals had to develop compelling hypotheses for both the product offering and the business model. Findings Need, Approach, Benefits per costs and Competition (NABC). the methodology Carlson and his team developed, contains the fundamental framework for creating customer value, it applies to the entire enterprise. It brings all functions together using a short, easy to remember meme that starts every conversation with a focus on customer need. Practical implications One of the most spectacular and best-known SRI innovation wins was Siri, the intelligent personal computer assistant and on-line knowledge navigator, an integral part of the iPhone. As a case example, Siri illustrates the power of the NABC approach. Originality/value Carlson stresses that the key element in SRI’s success with Siri was not just the technology. It was getting the entire value proposition right. “One of the things that changed at SRI was the realization that we needed to have really solid working hypotheses, both for the product and the business model, before we started spending significant money on technology. That’s one of the biggest mistakes firms make. They rush ahead and want to build the product before they de-risk their value propositions.

A neural observer for sensorless speed control of servomotors

2014 ◽  
Vol 31 (8) ◽  
pp. 1668-1678 ◽  
Author(s):  
Jenq-Ruey Horng ◽  
Ming-Shyan Wang ◽  
Tai-Rung Lai ◽  
Sergiu Berinde
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Design Methodology ◽  
Computation Time ◽  
Elman Neural Network ◽  
Content Type ◽  
On Line ◽  
Future Work ◽  
Practical Implications ◽  
Neural Speed

Purpose – Extensive efforts have been conducted on the elimination of position sensors in servomotor control. The purpose of this paper is to aim at estimating the servomotor speed without using position sensors and the knowledge of its parameters by artificial neural networks (ANNs). Design/methodology/approach – A neural speed observer based on the Elman neural network (NN) structure takes only motor voltages and currents as inputs. Findings – After offline NNs training, the observer is incorporated into a DSP-based drive and sensorless control is achieved. Research limitations/implications – Future work will consider to reduce the computation time for NNs training and to adaptively tune parameters on line. Practical implications – The experimental results of the proposed method are presented to show the effectiveness. Originality/value – This paper achieves sensorless servomotor control by ANNs which are seldom studied.

Improved GM(1, 1) model based on concave sequences and its applications

2017 ◽  
Vol 7 (3) ◽  
pp. 343-352
Author(s):  
Xinhai Kong ◽  
Peng Zhang ◽  
Xin Ma
Keyword(s):  
Design Methodology ◽  
Modeling Method ◽  
Content Type ◽  
Sequence Modeling ◽  
Model Based ◽  
Convex Sequence ◽  
Gas Consumption ◽  
Symmetry Transformations ◽  
Natural Gas Consumption ◽  
Practical Implications

Purpose The purpose of this paper is to improve the GM(1, 1) model based on concave sequences. Design/methodology/approach First, the restored sequence of the GM(1, 1) model is proved to be convex, and the residual characters of the GM(1, 1) model for concave sequences are analyzed. Second, two symmetry transformations are introduced to transform an original concave sequence into a convex sequence, and then the GM(1, 1) model is established based on the convex sequence. Findings Compared with the traditional modeling method, the new method has high accuracy and is applicable for all concave sequence modeling. Practical implications Two cases are used to illustrate the superiority of this modeling method. Case A is to predict China’s per capita natural gas consumption, and case B is to predict the annual output of an oilfield. Originality/value The application scope of GM (1, 1) model is greatly extended.

Introducing a concept for efficient design of EFQM excellence model

2015 ◽  
Vol 27 (4) ◽  
pp. 382-396 ◽  
Author(s):  
Seyed Amir Bolboli ◽  
Markus Reiche
Keyword(s):  
Corporate Culture ◽  
Design Methodology ◽  
Review Of Literature ◽  
Efficient Design ◽  
Maturity Level ◽  
Comprehensive Review ◽  
Content Type ◽  
Model Based ◽  
Practical Implications

Purpose – The purpose of this paper is to propose a roadmap for operationalizing EFQM excellence model based on the RADAR logic and in parallel develop a new concept for selecting the firm-specific EFQM measures based on the level of maturity and the prevailing corporate culture. Design/methodology/approach – A comprehensive review of literature leads to a clarification of the relation between EFQM measures and RADAR logic and also identification of the requirements for assessment of culture and determination of maturity level in the context of EFQM excellence model. Based on these requirements, existing culture assessment approaches and maturity assessment methods have been evaluated. Findings – The main outcome of this research is a new concept for efficient design of EFQM excellence model. This concept consist of three main parts: assessment of culture types in context of EFQM; assessment of maturity level; and design of EFQM measures based on RADAR logic. The findings are expected to reduce the effort for implementation of EFQM by designing tailored measures that fit to the existing culture and maturity level. Practical implications – The findings of this study are relevant to multinational large firms that deal with EFQM or similar excellence models. Originality/value – This paper presents a new concept for designing EFQM in the light of prevailing corporate culture and maturity level, which in one hand needs fewer resources and on the other hand it is more effective in implementation.

Designing training in organic farming on a multinational basis

2016 ◽  
Vol 33 (2) ◽  
pp. 99-114
Author(s):  
Raquel P.F. Guiné ◽  
Daniela V.T.A Costa ◽  
Paula M.R. Correia ◽  
Cristina A. Costa ◽  
Helena E. Correia ◽  
...  
Keyword(s):  
Organic Farming ◽  
Design Methodology ◽  
Training Programs ◽  
Target Population ◽  
North Central ◽  
Content Type ◽  
On Line ◽  
Level Of Significance ◽  
Training Opportunities ◽  
Practical Implications

Purpose – The purpose of this paper is to obtain information to characterize potential trainees seeking training programs about organic farming in the form of mobile learning. This information is expected to allow for establishing a set of guidelines to design mobile training opportunities that could match the potential clients’ wishes. Design/methodology/approach – For this survey an on-line questionnaire was used, translated into the languages of the participating countries (Portugal, Spain, Slovakia, Hungary, UK, Italy and Turkey), and in the end 133 consented valid questionnaires were obtained. The data analysis was made with SPSS and included basic descriptive statistics, crosstabs and χ2 tests, considering a level of significance of 5 per cent. Findings – The results obtained in the present study indicate that designing training programs in organic farming for a wide target population should attend to the differences between countries, which showed to significantly influence the preferences of the possible clients for this type of training. Practical implications – This study provided valuable information for use in the preparation of training programs for adults who want to expand their knowledge on organic farming, in order to prepare courses more in accordance with their preferences. Originality/value – The fact that the study was undertaken in several countries, including North, Central and South Europe, is a positive indicator that globally accepted courses could be implemented successfully. To the knowledge no such work was undertaken up to the present, thus confirming the originality of the study presented.

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