Admittance control is a typical complaint control methodology. Traditionally, admittance control systems are based on a dynamical relationship described by Voigt model. By…
Abstract
Purpose
Admittance control is a typical complaint control methodology. Traditionally, admittance control systems are based on a dynamical relationship described by Voigt model. By contrast, after changing connection of spring and damper, Maxwell model produces different dynamics and has shown better impact absorption performance. This paper aims to design a novel compliant control method based on Maxwell model and implement it in a robot catching scenario.
Design/methodology/approach
To achieve this goal, this paper proposed a Maxwell model based admittance control scheme. Considering several motion stages involved in one catching attempt, the following approaches are adopted. First, Kalman filter is used to process the position data stream acquired from motion capture system and predict the subsequent object flying trajectory. Then, a linear segments with parabolic blends reaching motion is generated to achieve time-optimal movement under kinematic and joint inherent constraints. After robot reached the desired catching point, the proposed Maxwell model based admittance controller performs such as a cushion to moderate the impact between robot end-effector and flying object.
Findings
This paper has experimentally demonstrated the feasibility and effectiveness of the proposed method. Compared with typical Voigt model based compliant catching, less object bounding away from end-effector happens and the success rate of catching has been improved.
Originality/value
The authors proposed a novel Maxwell model based admittance control method and demonstrated its effectiveness in a robot catching scenario. The author’s approach may inspire other related researchers and has great potential of practical usage in a widespread of robot applications.
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The purpose of this study was to investigate the effects of deformation-induced martensite on electrochemical corrosion behaviors of 304 austenitic stainless steel in a simulated…
Abstract
Purpose
The purpose of this study was to investigate the effects of deformation-induced martensite on electrochemical corrosion behaviors of 304 austenitic stainless steel in a simulated primary water environment of a pressurized water reactor nuclear power plant with boric acid and lithium hydroxide contaminated with chloride by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), Mott–Schotty curves and X-ray photoelectron spectroscopy (XPS).
Design/methodology/approach
The effects of deformation-induced martensite transformation on electrochemical corrosion behaviors of 304 austenitic stainless steel was investigated in a simulated primary water environment of a pressurized water reactor nuclear power plant with boric acid and lithium hydroxide contaminated with 0.1 M Cl− by potentiodynamic polarization, EIS, Mott–Schotty curves and XPS in this paper.
Findings
The results revealed that the martensitic phase contents increased with the level of cold deformation. The general corrosion current density and the corrosion potential increased and decreased, respectively, with the increase of cold deformation degree. However, the pitting potential decreased as the cold deformation increased up to 20 per cent, then a slight increase was observed at 35 per cent cold working. It was found from Mott–Schottky curves and XPS analysis that as the cold deformation degree increased from 0 to 35 per cent, the doping concentrations of the oxide films increased; however, the film thickness decreased, which indicates that both density and integrity of the films are degraded significantly as the deformation degree increases, and this ultimately contributes to the significant increment of the general corrosion rate and reduction of the pitting corrosion resistance.
Originality/value
The effects of deformation-induced martensite transformation on electrochemical corrosion behaviors of 304 austenitic stainless steel was investigated in a simulated primary water environment of a pressurized water reactor nuclear power plant with boric acid and lithium hydroxide contaminated with 0.1 M Cl− by potentiodynamic polarization, EIS, Mott–Schotty curves and XPS in this paper.
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La complexité de l'analyse et du traitement des données relatives à la création et aux conséquences d'un nouveau mega projet est souvent assez grande. La détermination des effets…
Abstract
La complexité de l'analyse et du traitement des données relatives à la création et aux conséquences d'un nouveau mega projet est souvent assez grande. La détermination des effets de l'implantation d'un projet touristique d'envergure, résultant d'une nou‐velle demande exogène telle les dépenses touri‐stiques, touchent, à titre d'exemple, à la création d'emplois et aux investissements nouveaux requis.
Excellencies Ladies and Gentlemen At the end of this memorable 33rd Congress of our Association, I would like to thank very heartly our hosts H.E. E.W. Mwangale, Minister for…
Abstract
Excellencies Ladies and Gentlemen At the end of this memorable 33rd Congress of our Association, I would like to thank very heartly our hosts H.E. E.W. Mwangale, Minister for Tourism and Wildlife, the Organizing Committee, presided by Mr. Maliti as well as to Universal Safary Tours as executing agency for having done everything to make our stay in Kenya pleasant and attractive.
Jane Barlow, Doug Simkiss and Sarah Stewart‐Brown
The aim of this article is to summarise the available evidence from systematic reviews about the effectiveness of interventions to prevent or treat child physical abuse and…
Abstract
The aim of this article is to summarise the available evidence from systematic reviews about the effectiveness of interventions to prevent or treat child physical abuse and neglect. A computerised search was undertaken of major electronic databases up to December 2005 using key search terms. Only systematic reviews were included in which the primary studies evaluated the effectiveness of targeted or indicated interventions for child physical abuse or neglect. A total of 31 systematic reviews were identified and 15 met all the inclusion criteria. They covered a range of interventions/services, including home visiting, parenting programmes, multi‐component interventions, intensive family preservation services, family‐focused casework and multi‐systemic family therapy. There was limited evidence of the effectiveness of services in improving objective measures of abuse and neglect, due in part to methodological issues involved in their measurement, but good evidence of modest benefits in improving a range of outcomes that are associated with physical abuse and neglect, including parental and family functioning and child development. The results also showed some interventions (eg. media‐based and perinatal coaching) to be ineffective with high‐risk families. The evidence provided by these reviews has clear implications for children's services in the UK and other western developed countries.
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Es ist mir eine besondere Freude, Sie nach 1965, wo wir die Probleme der Expansion im Fremdenverkehr diskutierten, zum zweitenmal in Ungarns Kapitale Budapest zum 39…
Abstract
Es ist mir eine besondere Freude, Sie nach 1965, wo wir die Probleme der Expansion im Fremdenverkehr diskutierten, zum zweitenmal in Ungarns Kapitale Budapest zum 39. AIEST‐Kongress zu begrssen und willkommen zu heissen.
Discusses the transfer of undertakings in the UK, referring to the Transfer of Undertakings (Protection of Employment) Regulations of 1981, the Employment Rights Act 1996, and the…
Abstract
Discusses the transfer of undertakings in the UK, referring to the Transfer of Undertakings (Protection of Employment) Regulations of 1981, the Employment Rights Act 1996, and the Acquired Rights Directive 1977. Provides the raison d’etre of the Acquired Rights Directive and outlines how it was implemented in the UK. Talks about the confusing jurisprudence of the European and British courts, mentioning the European Court of Justice’s challenges to the directive, the 1994 proposals, amended 1997 proposals, the Commission’s memorandum of 1997 and the UK government’s consultation papers. Describes how the European Directive is applied and interpreted in relation to the Acquired Rights Directive and transfer of undertakings. Outlines the regulations controlling compulsory competitive tendering. Points out the obligation to inform and consult on the transfer of an undertaking and how the directive is enforced if this fails to occur. Notes the effect a relevant transfer has on existing collective agreements and the legal implications of dismissing employees by reason of the relevant transfer. Looks at the European Commission’s proposal for a directive on safeguarding employees’ rights in the event of transfer and the implications that would have on UK business. Concludes that a new directive is needed, building on the 1977 Directive but ironing out its inconsistencies.
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In der aktuellen Diskussion ber den Fremdenverkehr allgemein und die Fremdenverkehrspolitik im besonderen stehen zur Zeit — insbesondere im Alpenraum — Umweltaspekte im…
Abstract
In der aktuellen Diskussion ber den Fremdenverkehr allgemein und die Fremdenverkehrspolitik im besonderen stehen zur Zeit — insbesondere im Alpenraum — Umweltaspekte im Vordergrund 1). Dies rechtfertigt zweifellos das Adjektiv ‘umweltorientiert’ im Zusammenhang mit der Fremdenverkehrspolitik. Dennoch soll hier zunächst eher all‐gemein auf die Fremdenverkehrspolitik und ihre wirtschaftlichen Ziele eingegangen werden; letztlich wird sich herausstellen, dass zwar jede Fremdenverkehrspolitik auf Umweltbelange Bedacht nehmen muss, wenn sie Nachfrage anziehen und damit ihrem Anspruch auf Erreichung bestimmter regionaler Wirtschaftsziele gerecht werden will, dass aber vor allem in der Frage der touristischen Landschaft Zielkonflikte zwischen der Erreichung wirtschaftspolitischer Ziele und Umweltfragen auftreten können.