75 research outputs found

    Uncalibrated eye-to-hand visual servoing using inverse fuzzy models

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    (c) 2007 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.A new uncalibrated eye-to-hand visual servoing based on inverse fuzzy modeling is proposed in this paper. In classical visual servoing, the Jacobian plays a decisive role in the convergence of the controller, as its analytical model depends on the selected image features. This Jacobian must also be inverted online. Fuzzy modeling is applied to obtain an inverse model of the mapping between image feature variations and joint velocities. This approach is independent from the robot's kinematic model or camera calibration and also avoids the necessity of inverting the Jacobian online. An inverse model is identified for the robot workspace, using measurement data of a robotic manipulator. This inverse model is directly used as a controller. The inverse fuzzy control scheme is applied to a robotic manipulator performing visual servoing for random positioning in the robot workspace. The obtained experimental results show the effectiveness of the proposed control scheme. The fuzzy controller can position the robotic manipulator at any point in the workspace with better accuracy than the classic visual servoing approach.info:eu-repo/semantics/publishedVersio

    RFID together with multi-agent systems to control global value chains

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    Nowadays, the cooperative intelligent transport systems are part of a largest system. Transportations are modal operations integrated in logistics and, logistics is the main process of the supply chain management. The supply chain strategic management as a simultaneous local and global value chain is a collaborative/cooperative organization of stakeholders, many times in co-opetition, to perform a service to the customers respecting the time, place, price and quality levels. The transportation, like other logistics operations must add value, which is achieved in this case through compression lead times and order fulfillments. The complex supplier's network and the distribution channels must be efficient and the integral visibility (monitoring and tracing) of supply chain is a significant source of competitive advantage. Nowadays, the competition is not discussed between companies but among supply chains. This paper aims to evidence the current and emerging manufacturing and logistics system challenges as a new field of opportunities for the automation and control systems research community. Furthermore, the paper forecasts the use of radio frequency identification (RFID) technologies integrated into an information and communication technologies (ICT) framework based on distributed artificial intelligence (DAI) supported by a multi-agent system (MAS), as the most value advantage of supply chain management (SCM) in a cooperative intelligent logistics systems. Logistical platforms (production or distribution) as nodes of added value of supplying and distribution networks are proposed as critical points of the visibility of the inventory, where these technological needs are more evident

    Avaliação da toxicidade das favas de Stryphnodendron fissuratum (Mimosoideae) em vacas gestantes

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    Com o objetivo de avaliar a toxicidade de diferentes concentraçÔes das favas de Stryphnodendron fissuratum em vacas prenhes, as favas desta ĂĄrvore foram moĂ­das, misturadas Ă  ração comercial e fornecidas a oito vacas nas doses totais de 6,5g/kg, 7,5g/kg, 9g/kg e 10g/kg. Os animais que receberam doses de 6,5g/kg pariram bezerros normais e aqueles que receberam 7,5g/kg pariram bezerros fracos que nĂŁo sobreviveram. Doses de 9g/kg resultaram no nascimento de um bezerro imaturo e de outro bezerro com distiquĂ­ase, opacidade congĂȘnita das cĂłrneas e microftalmia. Ambas as vacas que ingeriram 10g/kg morreram, porĂ©m uma vaca abortou antes de morrer. Nas vacas que morreram, as lesĂ”es macroscĂłpicas e histolĂłgicas do sistema digestivo e fĂ­gado foram semelhantes Ă s descritas anteriormente na intoxicação por S. fissuratum. Nos bezerros e no feto abortado nĂŁo foram observadas lesĂ”es macroscĂłpicas ou histolĂłgicas significantes. A anĂĄlise fitoquĂ­mica dos extratos metanĂłlicos das favas de S. fissuratum revelou a presença de taninos hidrossolĂșveis, proantocianidinas, leucoantocianidinas e da saponina triterpĂ©nica ÎČ-amirina. Saponinas triterpĂ©nicas tĂȘm sido associadas com a toxicidade das favas de Stryphnodendron spp. e Enterolobium spp., que causam sinais clĂ­nicos semelhantes aos observados na intoxicação por S. fissuratum. Esta pesquisa confirmou a toxicidade das favas de S. fissuratum para bovinos, no entanto nĂŁo foram confirmados os efeitos abortivos das mesmas, pois o aborto e as mortes neonatais observadas podem ser decorrentes dos efeitos tĂłxicos da planta nas mĂŁes. Novas pesquisas sĂŁo necessĂĄrias para pesquisar se as favas da planta causam malformaçÔes semelhantes Ă s observas em um dos bezerros nascidos vivos
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