55 research outputs found

    A Real-time Network for a Solid-State Transformer

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    IIoT Based Efficiency Optimization in Logistics Applications

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    The Industrial Internet of Thing (IIoT) approach to an Industry plant design, devises a comprehensive interconnection of the system components, from sections up to single devices, in order to get a general and punctual understanding of the process. Such an intelligent network, mostly based on Ethernet basic layers, when properly conceived, should be able to add relevant value to the plant operation. This paper shows how, within the IIoT frame topics, the plant efficiency can be addressed and bring relevant improvement. The reason is that variables directly related to the energy consumption, such as current, electric power, actuator and motor torque, speed, etc., can be timely and easily monitored in the entire plant, since they are already conveyed on the network, due to real time control and diagnostics purpose. A power consumption diagram can be derived, and give hints on how to optimize operations, based on some efficiency index. The paper, after a general discussion, proves it with practical examples based on a Gantry robot, driven in an EtherCAT based automation network, and on the stacker cranes of an automated warehouse

    Time Sensitive Networking Protocol Implementation for Linux End Equipment

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    By bringing industrial-grade robustness and reliability to Ethernet, Time Sensitive Networking (TSN) offers an IEEE standard communication technology that enables interoperability between standard-conformant industrial devices from any vendor. It also eliminates the need for physical separation of critical and non-critical communication networks, which allows a direct exchange of data between operation centers and companies, a concept at the heart of the Industrial Internet of Things (IIoT). This article describes creating an end-to-end TSN network using specialized PCI Express (PCIe) cards and two final Linux endpoints. For this purpose, the two primary standards of TSN, IEEE 802.1AS (regarding clock synchronization), and IEEE 802.1Qbv (regarding time scheduled traffic) have been implemented in Linux equipment as well as a configuration and monitoring system.This work has been supported by the Ministerio de EconomĂ­a y Competitividad of Spain within the project TEC2017-84011-R and FEDER funds as well as by the Department of Education of the Basque Government within the fund for research groups of the Basque university system IT978-16

    Real-Time Ethernet Networks: a practical approach to cycle time influence in control applications

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    Vivemos num mundo cada vez mais digital e informatizado onde existe uma constante necessidade de interligação entre tudo e todos. Os sistemas robóticos modernos não escapam a esta necessidade e, por isso, é preciso adaptå-los. Existem no mercado vårias soluçÔes de redes de comunicação de tempo real, jå bem estabelecidas, mas em todas se encontra a mesma lacuna: a escassez de material educativo acerca delas. Este documento pretende apresentar as duas soluçÔes propostas para colmatar um pouco esta lacuna na rede EtherCAT e demonstrar o trabalho de pesquisa e estudo preliminar efetuado para suportar e servir de ponto de partida para o desenvolvimento aprofundado de uma das soluçÔes. Nos capítulos seguintes serå explicitado o contexto e motivação para a realização deste projeto, os objetivos que propomos alcaçar, uma descrição do problema incluindo a sua caraterização, uma apresentação não exaustiva da tecnologia por detrås da rede EtherCAT, a explicação das soluçÔes propostas e, por fim, um planeamento de tarefas e objetivos com calendarização dos mesmos

    Development of functional safety applications for Autec products. Study of protocols: CANopen, CANopen Safety, FSOE and ProfiSafe

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    This thesis has the principal goal of developing intrinsic safety applications in distributed real-time industrial systems, mainly based on fieldbuses and RTE networks. To achieve this important objective the first part of this elaborate provides an introduction of the principal protocols, such as CANopen Safety, Fail safe Over Ethercat (FSOE) and Profisafe, used for the safety relevant applications in the automation environment,analysing properties,story and the use of them by industry

    A new method for motion synchronization among multivendor’s programmable controllers

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    This paper is aimed at increasing the number of possible architectures of distributed control systems by investigating and developing novel methods for the synchronization of axes between PLCs and iPCs of different vendors. In order to find a global solution to this problem, particular attention has been focused on programmable controllers that can manage axes by means of point-by-point control or motion instructions. Two synchronization algorithms have been developed and validated for real and virtual axes; they differ in computational load so that they can be used with programmable controllers having high or low computational performances

    Industriella realtidsethernet för maskinautomation

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    During the last two decades, Ethernet has become the de facto standard in office level networks. There are several motivations for using Ethernet also in control networks, including the abundance of low cost components, the high data transfer rates and the possibility of vertical integration with other networks of the organization. The first in­dustrial implementation of Ethernet was for communication between different devices on the controller level. Modern real-time industrial Ethernet technologies, like the ones studied in this thesis, have brought Ethernet also down to the field level. The thesis is divided into two sections. The first section contains presentations of the seven most used real-time industrial Ethernet technologies. The second section contains a more thorough study of EtherCAT, the one of the seven technologies that promise the best real-time performance. The main goals are to provide a review of the different tech­nologies available and to study the suitability of EtherCAT in the control networks of machine automation systems. In the first section, different real-time industrial Ethernet technologies are divided into three groups based upon how much they differ from standard office Ethernet. It is found that the technologies built entirely upon standard office Ethernet do in them­selves not promise any real-time capabilities. Their biggest weakness is the slow pro­cessing of the software communication protocol stack. The technologies that use stan­dard Ethernet hardware but dedicated software are good for soft real-time applications, but the lack of accurate synchronization between the devices makes them unsuitable for applications demanding hard real-time behavior. The technologies that use both special hardware and software offer superior real-time performance but are not as open to inte­gration with standard office Ethernet networks as the other solutions. The second section of the study contains three parts. In the first of them, a small test system is built to examine the suitability of EtherCAT for the closed loop control of a variable alternate current (AC) drive. In the second part, the availability of open source initiatives concerning EtherCAT is explored. In the third part, the possibility for master device redundancy in EtherCAT is investigated. The study indicates that EtherCAT achieves the short communication cycle times and accurate synchronization promised. Short cycle times are indeed needed as direct communication between slave devices is not supported in EtherCAT and thus the efficiency of the communication is almost totally dependent on the cycle time. EtherCAT networks are relatively easy to configure and maintain as there are comprehensive software suites available, both as commercial pro­grams and open source initiatives and for a variety of different operating systems. The least developed feature of EtherCAT proved to be the support for master device redun­dancy. Solutions for master redundancy are available, but more as concepts than as ready-to-use features. /Kir10Under de senaste tvĂ„ decennierna har Ethernet blivit nĂ„got av en de facto standard för nĂ€tverk i kontorsmiljö. Det finns flera motiv för att anvĂ€nda Ethernet Ă€ven i kontroll­nĂ€tverk, bland andra god tillgĂ„ng av billiga komponenter, hög dataöverföringshastighet och möjligheter för vertikal integration med nĂ€tverk pĂ„ andra nivĂ„er av organisationen. Den första industriella tillĂ€mpningen av Ethernet var för kommunikation mellan olika kontrollenheter. Moderna realtidslösningar för industriella Ethernet-nĂ€tverk har fört Ethernet ocksĂ„ ner till fĂ€ltnivĂ„. Det hĂ€r diplomarbetet Ă€r uppdelat i tvĂ„ delar. Den första delen innehĂ„ller presen­tationer av de sju mest anvĂ€nda realtidslösningarna för industriella Ethernet-nĂ€tverk. Den andra delen innehĂ„ller en mer djupgĂ„ende studie av EtherCAT, den av de sju lösningarna som utlovar bĂ€st realtidsprestanda. De mest centrala mĂ„len Ă€r att ge en över­syn av de olika realtidslösningarna som finns tillgĂ€ngliga för industriella Ethernet-nĂ€tverk samt att undersöka hur lĂ€mpligt EtherCAT Ă€r som kontrollnĂ€tverk för maskin­automation. Inledningsvis delas de olika lösningarna in i tre grupper pĂ„ bas av hur mycket de skiljer sig frĂ„n vanliga kontorsnĂ€tverk. Det visar sig att de lösningar som helt bygger pĂ„ samma teknik som anvĂ€nds i kontorsnĂ€tverk i sig sjĂ€lva inte kan utlova nĂ„gon som helst realtidskapacitet. Deras största svaghet Ă€r den resurskrĂ€vande behandlingen av de kommunikationsprotokoll som anvĂ€nds i kontorsnĂ€tverk. Det Ă€r dock möjligt att konstruera lösningar med relativt bra realtidsbeteende utgĂ„ende frĂ„n de hĂ€r lösningarna bara man vĂ€ljer rĂ€tt Ethernet-komponenter och tillrĂ€ckligt kraftfulla mikroprocessorer i nĂ€tverksstationerna. De lösningar som anvĂ€nder vanlig Ethernet-maskinvara men egen programvara Ă€r bra för mjuka realtidssystem, men de brister i synkroniseringen mellan enheterna och Ă€r sĂ„lunda inte tillrĂ€ckligt deterministiska för hĂ„rda realtidssystem. De lösningar som anvĂ€nder bĂ„de egen hĂ„rdvara och egen mjukvara erbjuder överlĂ€gsen realtidsprestanda som öppnar nya möjligheter för effektivare reglering av olika system. Å andra sidan Ă€r de hĂ€r lösningarna inte lika öppna för integration med vanliga kontorsnĂ€tverk som de lösningar som har mer likheter med vanliga kontorsnĂ€tverk. Den andra delen av studien inriktar sig pĂ„ EtherCAT. EtherCAT Ă€r ett sĂ„ kallat master/slave-nĂ€tverk, det vill sĂ€ga att en av stationerna i nĂ€tverket styr kommuni­kationen och de andra i allmĂ€nhet inte sjĂ€lva kan initiera nĂ„gon form av kommuni­kation. Den mest centrala funktionsprincipen för EtherCAT Ă€r att de olika slav-stationerna logiskt Ă€r ordnade i en kedja och att alla meddelanden passerar genom alla slav-stationer och blir ocksĂ„ lĂ€sta och skrivna till av flera slav-stationer. I relativt smĂ„ nĂ€tverk betyder det hĂ€r att det bara skickas ett meddelande per kommunikationscykel. Meddelandena hanteras av speciell hĂ„rdvara i slav-stationerna och detta sker sĂ„ snabbt att meddelandena bara blir fördröjda med brĂ„kdelen av en mikrosekund. Master-stationen, dĂ€remot, Ă€r oftast konstruerad utan speciell hĂ„rdvara och bestĂ„r vanligen av en PC med realtidsoperativsystem och speciell mjukvara, ett sĂ„ kallad EtherCAT master-program. Det att mastern bestĂ„r av standard Ethernet hĂ„rdvara betyder att den har relativt dĂ„lig timing-kapacitet. DĂ€rför Ă€r de olika slav-enheterna i ett EtherCAT nĂ€tverk i stĂ€llet vanligen synkroniserade efter den första slav-enheten i kedjan. En synkroniseringsexakthet pĂ„ mycket bĂ€ttre Ă€n en mikrosekund utlovas och den kan anvĂ€ndas bĂ„de till att Ă„stadkomma reaktioner pĂ„ en exakt given tidpunkt och exakta tidsangivelser för nĂ€r ett processvĂ€rde Ă€r uppmĂ€tt. Studien av EtherCAT Ă€r indelad i tre avsnitt. I det första av dem byggs ett litet testsystem för att undersöka hur lĂ€mpligt EtherCAT Ă€r som kontrollnĂ€tverk för Ă„terkopplad styrning av en frekvensomriktare. Den viktigaste enskilda egenskapen som krĂ€vs av ett kommunikationsnĂ€tverk för den hĂ€r tillĂ€mpningen Ă€r att frekvensomriktaren ofta och snabbt fĂ„r korrekt information om drivaxelns position. Det Ă€r ocksĂ„ viktigt att positionsangivelserna Ă€r ackompanjerade av exakt information om nĂ€r de Ă€r uppmĂ€tta. Studien visar att det Ă€r möjligt att uppnĂ„ bĂ„da de hĂ€r egenskaperna med hjĂ€lp av EtherCAT. Det att direkt kommunikation mellan slav-stationerna i ett EtherCAT-nĂ€tverk inte understöds medför visserligen att överföringen av positions­datan tar tvĂ„ kommunikationscykler i ansprĂ„k, men eftersom det Ă€r möjligt att uppnĂ„ cykel­tider sĂ„ korta som 133 ”s torde prestandan i alla fall rĂ€cka för de flesta system. Det hĂ€r medför dock att cykeltiderna mĂ„ste hĂ„llas lĂ„ga Ă€ven om systemet i övrigt inte skulle krĂ€va det. I det andra avsnittet undersöks tillgĂ„ngen pĂ„ öppen kĂ€llkodsbaserad programvara för EtherCAT. Det krĂ€vs ingen licens för att utveckla EtherCAT master-programvara, sĂ„ det finns en mĂ€ngd olika program för flera olika operativsystem pĂ„ marknaden. Ett par av dem Ă€r baserade pĂ„ öppen kĂ€llkod. Ett av de mest intressanta Ă€r EtherLAB frĂ„n Ingenieurgemeinschaft IgH. Det Ă€r i huvudsak utvecklat för Linux och innehĂ„ller förutom master-programvaran Ă€ven mjukvara för diagnostik och för att generera kontrollrutiner frĂ„n modeller skapade med Matlab/Simulink. I det hĂ€r avseendet Ă€r det till och med kraftfullare Ă€n den mest anvĂ€nda kommersiella programvaran för EtherCAT, TwinCAT frĂ„n Beckhoff Automation, som igen körs under MS Windows. I det tredje avsnittet granskas möjligheterna att duplicera den enhet som styr ett EtherCAT nĂ€tverk, sĂ„ kallad master-redundans. Studien presenterar en lösning utvecklad av Beckhoff Automation. Det visar sig att detta Ă€r en relativt sett dĂ„ligt utvecklad egenskap i EtherCAT. Den presenterade metoden medför till exempel att det tar nĂ€stan en hel sekund innan reserv-mastern tar över ifall det uppstĂ„r fel i den primĂ€ra, dessutom Ă€r funktionen för synkronisering av klockorna i slav-enheterna inte tillgĂ€nglig nĂ€r den hĂ€r metoden anvĂ€nds. Studien presenterar Ă€ven en idĂ© om en annan möjlig lösning för att Ă„stadkomma master-redundans i EtherCAT nĂ€tverk. Fördelen med den Ă€r att den skulle göra funktionen för att synkronisera klockorna i slav-enheterna möjlig Ă€ven fast systemet innehĂ„ller master-redundans. BĂ„da de presenterade lösningarna Ă€r mer koncept Ă€n funktioner fĂ€rdiga att anvĂ€nda, detta gĂ€ller i synnerhet den andra lösningen, som Ă€nnu bara Ă€r i idĂ©stadiet. Bristen pĂ„ vĂ€l fungerande lösningar för master-redundans gör att EtherCAT system bör konstrueras sĂ„ att korta stopp i kom­munikationen inte kan skada systemet i sig sjĂ€lv, intilliggande system eller mĂ€nniskor som Ă€r i kontakt med systemet

    Design of a New High Bandwidth Network for Agricultural Machines

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    Ethernet is by now the most adopted bus for fast digital communications in many environments, from household entertainment to PLC robotics in industrial assembly lines. Even in automotive industry, the interest in this technology is increasingly growing, pushed forward by research and by the need of high throughput that high dynamics distributed control demands. Although 100base-TX physical layer (PHY) does not seem to meet EMC requirements for vehicular and heavy-duty environments, OPEN Alliance BroadR Reach (soon becoming IEEE standard as IEEE 802.3bw) technology is the most promising and already adopted Ethernet-compatible PHY, reaching 100Mbps over an unshielded twisted pair. An agricultural machine is usually a system including tractor and one or more implements attached to it, to the back or to the front. Nowadays, a specific CAN-based distributed control network support treatments and applications, namely ISOBUS, defined by ISO 11783. This work deals with architectural and technological aspects of advanced Ethernet networks in order to provide a high-throughput deterministic network for in-vehicle distributed control for agricultural machinery. Two main paths of investigation will be presented: one concerning the prioritization of standard Ethernet taking advantage of standard ways of prioritization in well-established technologies; the other changing the channel access method of Ethernet using an industrial fieldbus, chosen after careful investigation. The prioritization of standard Ethernet is performed at two, non-mutual exclusive layers of the ISO OSI stack: one at L3, using the diffserv (former TOS) Ip field; one at L2, using the priorities defined in IEEE 802.1p, used in IEEE 802.1q (VLAN). These choices have several implications in the specific field of application of the agricultural machines. The change of the access method, instead, focused on the adoption of a specific fieldbus, in order to grant deterministic access to the medium and reliability of communications for safety-relevant applications. After a survey, that will be reported, the Powerlink fieldbus was chosen and some modifications will be discussed in order to suit the scope of the research

    Relatório de Estågio na Inficon AG e na PT Inovação & Sistemas

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    This document focuses the projects developed during two independent internships, which were carried out at Inficon AG and PT Inovação & Sistemas. Since the research areas of both internships are unrelated, individual abstracts are presented
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