Industrial Control Systems (ICSs) manage critical infrastructures such as water treatment facilities, petroleum refineries, and power plants. ICSs are networked through Information Technology (IT) infrastructure for remote monitoring and control of physical processes. As ICSs integrate with IT infrastructure, IT vulnerabilities are carried over to the ICS environment. Previously proposed process controller security architectures maintain safe and stable plant operation even in the presence of attacks that exploit ICS vulnerabilities. Security architectures are process control system-level solutions that leverage isolated and trusted hardware (secure enclaves) for ICS security. Upon detecting an intrusion, the secure enclave switches control of the physical process to a high assurance controller, making a fail-safe plant operation. The process control loop components have an average lifespan of several decades. During this time, electromechanical components of process control loop may undergo aging that alters their characteristics and affects control loop performance. To deal with component aging and to improve control algorithm flexibility, updates to control loop parameters are required. Plant model, process control loop system specifications, and control algorithm-based security mechanisms at the secure enclave require parameter updates. ICSs have hundreds of process control components that may need be installed in hazardous environments and distributed across hundreds of square kilometers. Updating each component physically may lead to accidents, expensive travel, and increased downtime. Some ICS have allowable downtime of only 5 minutes per year. Hence, remote updates are desirable. A proposed dedicated and isolated hardware module at the secure enclave provides authentication of the update and ensures safe storage in a non-volatile memory. A protocol designed for update transmission through an untrusted ICS network provides resilience against network integrity attacks such as replay attacks. Encryption and authentication of the updates maintain integrity and confidentiality. During the normal plant operation, the hardware module is invisible to the other modules of the process control loop. The proposed solution is implemented on Xilinx Zynq-7000 programmable System-on-Chip to provide secure enclave updates. / Master of Science / Industrial Control Systems (ICSs) manage critical infrastructures such as water treatment facilities, petroleum refineries, and power plants. ICS process controllers interpret sensor output and depending on the set point, generate input signals for the actuator to control physical processes. The process controllers receive set points and periodically send process state to the supervisory network. For remote monitoring and control of physical processes, ICSs are networked through Information Technology (IT) infrastructure. As ICSs integrate with IT infrastructure, IT vulnerabilities are carried over to the ICS environment. Previously proposed process controller security architectures maintain safe and stable plant operation even in the presence of attacks that exploit ICS vulnerabilities. Security architectures are process control system-level solutions that leverage isolated and trusted hardware (secure enclaves) for ICS security. Upon detecting an intrusion, the secure enclave switches control of the physical process to a high assurance controller, making a fail-safe plant operation. The process control loop components have an average lifespan of several decades. During this time, electromechanical components of process control loop may undergo aging that alters their characteristics and affects control loop performance. To deal with component aging and to improve control algorithm flexibility, updates to control loop parameters are required. Plant model, process control loop system specifications, and control algorithm-based security mechanisms at the secure enclave require parameter updates. ICSs have hundreds of process control components that may need be installed in hazardous environments and distributed across hundreds of square kilometers. Updating each component physically may lead to accidents, expensive travel, and increased downtime. Some ICS have allowable downtime of only 5 minutes per year. Hence, remote updates are desirable. A proposed dedicated and isolated hardware module at the secure enclave provides authentication of the update and ensures safe storage in a non-volatile memory. A protocol designed for update transmission through an untrusted ICS network provides resilience against network integrity attacks such as replay attacks. Encryption and authentication of the updates maintain integrity and confidentiality. During the normal plant operation, the hardware module is invisible to the other modules of the process control loop. The proposed solution is implemented on Xilinx Zynq-7000 programmable System-on-Chip to provide secure enclave updates.

Thesis (M. Tech. (Engineering Electrical)) -- Central University of Technology, Free State, [2014] / This dissertation evaluates the software and hardware components used to develop a Reconfigurable Assembly System with an Integrated Information Management System. The assembly system consists of a modular Cartesian robot and vision system. The research focuses on the reconfigurability, modularity, scalability and flexibility that can be achieved in terms of the software and hardware components used within the system. The assembly system can be divided into high-level control and low-level control components. All information related to the product, Cartesian positioning and processes to follow resides in the Information Management System. The Information Management System is the high-level component and consists of a database, web services and low-levelcontrol drivers. The high-level system responds to the data received from the low-level systems and determines the next process to take place. The low-level systems consist of the PLC (Programmable Logic Controller) and the vision system. The PLC controls the Cartesian robot’s motor controllers and handles all events raised by field devices (e g. sensors or push buttons). The vision system contains a number of pre-loaded inspections used to identify barcodes and parts, obtain positioning data and verify the products’ build quality. The Cartesian robot’s positioning data and the vision system’s inspections are controlled by the Information Management System. The results showed that the high-level control software components are able to add more modularity and reconfigurability to the system, as it can easily adapt to changes in the product. The high-level control components also have the ability to be reconfigured while the assembly system is online without affecting the assembly system. The low-level control system is better suited to handling the control of motor controllers, field devices and vision inspections over an industrial network.

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: This work considers the control of reconfigurable assembly systems using a welding assembly system as a case study. The assembly system consists of a pallet magazine, a feeding system, an inspection and removal system, a welding system and a conveyor. The aim of the work is to compare PC and PLC as controllers, as well as to compare two different approaches to reconfigurable control. The control system of the pallet magazine was developed using a PC and a PLC. The PC control was programmed using Visual C#, while the PLC was programmed in Ladder Logic using Siemens S-300 STEP7. The two controllers were compared based on the attributes that measure the quality of a controller's software, which include its capability, availability, usability and adaptability. The approaches to reconfigurable control considered were the agent-based methodology and the IEC 61499 distributed control methodology, both of which were applied to the feeding system. The agent-based control system was implemented using the JADE agent platform, while the IEC 61499 distributed control system was implemented using the FBDK software kit. These two methods were compared based on the characteristics of a reconfigurable system, which include the system's modularity, integrability, convertibility, diagnosability, customization and scalability. The result obtained in comparing the PC to the PLC shows that the PLC performs better in terms of capability, availability and usability, while the PC performs better in terms of adaptability. Also, the result of the comparison between the agent-based control system and the IEC 61499 distributed control system shows that the agent-based control system performs better in terms of integrability, diagnosability and scalability, while the IEC 61499 distributed control system performs better in terms of modularity and customization. They are, however, on a par in terms of convertibility. / AFRIKAANSE OPSOMMING: Hierdie werk beskou die beheer van herkonfigureerbare monteringstelsels met 'n sweismonteringstelsel as gevallestudie. Die monteringstelsel bestaan uit 'n paletmagasyn, 'n voerstelsel, 'n inspeksie-en- verwyderingstelsel, 'n sweisstelsel en 'n voerband. Die mikpunt van die werk is om persoonlike rekenaars (PCs) en programmeerbare-logikabeheerders (PLCs) as beheerders te vergelyk, asook om twee verskillende benaderings tot herkonfigureerbare beheer te vergelyk. Die beheerstelsel van die paletmagasyn is ontwikkel met 'n PC en 'n PLC. Die PC-beheer is in Visual C# geprogrammeer, terwyl die PLC in leerlogika met Siemens S-300 STEP7 geprogrammeer is. Die twee beheerders is vergelyk in terme van die eienskappe wat die kwaliteit van 'n beheerder se sagteware meet en sluit in vermoë, beskikbaarheid, bruikbaarheid en aanpasbaarheid. Die benaderings tot herkonfigureerbare beheer wat oorweeg is, is die agent-gebaseerde metodologie en die IEC 61499 verspreide-beheermetodologie. Beide is op die voerstelsel toegepas. Die agent-gebaseerde beheerstelsel is geïmplementeer met behulp van die JADE agent-platform, terwyl die IEC 61499 verspreide stelsel geïmplementeer is met behulp van die FBDK sagteware-stel. Hierdie twee metodes se vergelyking is gebaseer op die eienskappe van 'n herkonfigureerbare stelsel, waarby die stelsel se modulariteit, integreerbaarheid, diagnoseerbaarheid, pasmaakbaarheid en skaleerbaarheid ingesluit is. Die resultate wat in die vergelyking tussen die PC en PLC verkry is, toon dat die PLC beter vaar in terme van vermoë, beskikbaarheid en bruikbaarheid, terwyl die PC beter vaar in terme van aanpasbaarheid. Die resultaat van die vergelyking tussen die agent-gebaseerde beheerstelsel en die IEC 61499 verspreide beheerstelsel wys dat die agent-gebaseerde beheerstelsel beter vaar in terme van integreerbaarheid, diagnoseerbaarheid en skaleerbaarheid, terwyl die IEC 61499 verspreide beheerstelsel beter vaar in terme van modulariteit en pasmaakbaarheid. Hulle is egter vergelykbaar in terme van omskepbaarheid.

Η προσομοίωση της κίνησης των ζώων αποτελεί αντικείμενο έρευνας στον τομέα της ρομποτικής από το 1960. Έκτοτε έχουν κατασκευαστεί πολλά ρομπότ τα οποία εξομοιώνουν πλήρως την κίνηση των θηλαστικών, των πτηνών και των ερπετών και συμπεριφέρονται ακριβώς όπως αυτά. Συγκεκριμένα στον τομέα των ερπετών ο Hirose το 1972 παρουσίασε το τον ACMIII, το πρώτο φίδι ρομπότ, το οποίο μπορούσε να κινηθεί μόνο σε λεία επιφάνεια, προσομοιώνοντας την κίνηση του φιδιού. Εν συνεχεία, με την πρόοδο της τεχνολογίας και τον πνευματικό κόπο χιλιάδων επιστημόνων, κατασκευάστηκαν διάφορα εξελιγμένα μοντέλα ρομπότ-φιδιών με τεράστιες δυνατότητες. Αποτελεί, πλέον, πραγματικότητα η ύπαρξη ρομπότ-φιδιών, που μπορούν να κινηθούν σε οποιαδήποτε επιφάνεια. Στη διπλωματική αυτή πραγματοποιήθηκε η κατασκευή και η λειτουργία ενός σύνθετου ενεργοποιητή αποτελούμενου από μια συστοιχία πνευματικών μυών πεπιεσμένου αέρα και ελεγχόμενου μέσω ενός προγραμματιζόμενου λογικού ελεγκτή (PLC). Τα έμβολα συνδέονται μεταξύ τους είτε με σταθερή είτε με ελεύθερη άρθρωση επιτρέποντας στη συστοιχία να κινηθεί ευθύγραμμα ή καμπυλόγραμμα αντίστοιχα. Κατά την ευθύγραμμη κίνηση η κατασκευή αποτελείται από 7 τεχνητούς μύες, οι οποίοι συνδέονται μεταξύ τους με σταθερή άρθρωση και τροφοδοτούνται από ψηφιακές βαλβίδες. Επίσης, η συστοιχία είναι εφοδιασμένη με μια συμπαγή σιδερένια κατασκευή ως ουρά και έναν αυτοσχέδιο μηχανισμό φρένων. Ο χρήστης, αφού φορτώσει το αντίστοιχο πρόγραμμα στην CPU του PLC, με το πάτημα ενός μπουτόν ξεκινά την κίνηση της διάταξης. Στο πρόγραμμα αυτό χρησιμοποιείται ένα πλήθος από χρονομετρητές οι οποίοι καθορίζουν πότε πραγματοποιείται η διαστολή και η συστολή των εμβόλων ρυθμίζοντας έτσι τη συμπεριφορά του πνευματικού ενεργοποιητή. Στην παρούσα διπλωματική αναλύθηκαν 3 μοτίβα ευθύγραμ-μης κίνησης. Στο πρώτο μοτίβο η συστολή και η διαστολή είναι ανεξάρτητες, στο δεύτερο έχουμε διαδοχική συστολή/διαδοχική διαστολή και στο τρίτο η διαστολή επικαλύπτει τη συστολή. Η διακοπή της κίνησης γίνεται μέσω του μπουτόν λήξης. Για το σενάριο της οφιοειδούς και της πλάγιας κίνησης η κατασκευή αποτελείται από 5 τεχνητούς πνευματικούς ενεργοποιητές. Οι 4 χρησιμοποιούνται ως ενεργό μέρος της συστοιχίας, ενώ ο πέμπτος ως κεφαλή. Ανάμεσα στα έμβολα υπάρχει αρθρωτή ζεύξη με δυνατότητα κίνησης. Έτσι, κατά τη συστολή και την διαστολή των μυών δημιουργείται μια γωνία μεταξύ τους. Ρυθμίζοντας αυτή τη γωνία κατάλληλα μέσω της πίεσης επιτυγχάνουμε την οφιοειδή κίνηση του σύνθετου πνευματικού ενεργοποιητή. Ο χρήστης μέσω μπουτόν έχει τη δυνατότητα να ελέγχει την κίνηση της συστοιχίας. Επιλέγει την έναρξη και τη λήξη της κίνησης καθώς και το αναποδογυρίζει. Στην ευθύγραμμη κίνηση εστιάσαμε την προσοχή μας στην εύρεση του βέλτιστου πλάνου κίνησης ώστε να επιτευχθεί το γρηγορότερο αποτέλεσμα. Από την άλλη μεριά στην καμπυλόγραμμη κίνηση τα πράγματα δεν ήταν τόσο απλά. Κύριο ζητούμενο εδώ ήταν η προσομοίωση της οφιοειδούς κίνησης. Η αδυναμία εφαρμογής του θεωρητικού υπόβαθρου που ήδη υπάρχει για τα φίδια-ρομπότ, εξαιτίας της ασυμμετρίας της κατασκευής, της αδυναμίας να επιτευχθούν οι επιθυμητές γωνίες λόγω παραμόρφωσης του σκελετού και της μη γραμμικής συμπεριφοράς της, οδήγησαν στη διενέργεια πολλών πειραμάτων ώστε να υπερκεραστούν οι δυσκολίες και να επιτευχθεί το επιθυμητό αποτέλεσμα. Παράλληλα, στην πλάγια κίνηση μελετήθηκε η ικανότητα μετακίνησης της συστοιχίας σε ανισόπεδα τερέν. Κατά τη διάρκεια των πειραμάτων παρουσιάστηκε μια πληθώρα προβλημάτων τα οποία έπρεπε να αντιμετωπιστούν τόσο στην ευθύγραμμη όσο και στην οφιοειδή κίνηση. Λόγω της μεγάλης δύναμης που ασκούν οι μύες κατά την εκτόνωσή τους και του μικρού συντελεστή τριβής του εδάφους του εργαστηρίου, η συστοιχία κατά τη διαστολή των εμβόλων ολίσθαινε προς τα όπισθεν, δημιουργώντας έτσι σημαντική καθυστέρηση στην συνολική μετακίνηση της συστοιχίας. Για την αντιμετώπιση του φαινομένου αυτού χρησιμοποιήθηκε ένα σιδερένιο βαρίδιο και ένα αυτοσχέδιο φρένο στην “ουρά” της συστοιχίας, που συγκρατούσαν τη συστοιχία κατά τη διαστολή των μυών και την ωθούσαν προς τα εμπρός. Αυτή η μεγάλη δύναμη των μυών ήταν πρόβλημα και για την καμπυλόγραμμη κίνηση, καθώς προκαλούσε παραμόρφωση του σκελετού, εισάγοντας έτσι σημαντικούς περιορισμούς στη μέγιστη πίεση των μυών. Ταυτόχρονα, οδηγούσε σε “χαλάρωση” των βιδών που συγκρατούσαν την κινούμενη άρθρωση. Εκτός αυτών, ένα επιπλέον εμπόδιο που παρουσιάστηκε ήταν η παρακώλυση της κίνησης από τους σωλήνες που τροφοδοτούσαν τα έμβολα. Αυτό το θέμα ήταν μείζονος σημασίας για την οφιοειδή κίνηση, καθώς αν δεν ομαδοποιούνταν κατάλληλα οι σωλήνες, η μετακίνηση της συστοιχίας ήταν μηδενική. Τέλος, οι βαλβίδες έπρεπε να είχαν τη δυνατότητα της εύκολης μετακίνησης, καθώς, λόγω του περιορισμένου μήκους σωλήνων, εισάγονταν περιορισμοί στο διάστημα που μπορούσε να διανύσει η συστοιχία. Τα θέματα αυτά αντιμετωπίσθηκαν με πρακτικούς τρόπους ώστε η μεταφορά των βαλβίδων να γίνεται εύκολα και με ασφάλεια, χωρίς να παρενοχλείται η κίνηση. Εν κατακλείδι, το αποτέλεσμα της προσπάθειας αυτής ήταν να δημιουργηθεί ένας σύνθετος ενεργοποιητής, ο οποίος έχει τη δυνατότητα να κινείται πλάγια, ευθύγραμμα, καθώς και να προσομοιώνει την κίνηση του φιδιού σε πολύ ικανοποιητικό βαθμό με μικρό όμως αποτέλεσμα ως προς την ταχύτητα. Η χρήση αισθητήρων για μέτρηση της γωνίας που δημιουργείται μεταξύ των εμβόλων και η κατασκευή πιο ανθεκτικού σκελετού, ώστε να αντέχει στη μεγάλη δύναμη που ασκούν οι μύες, θα οδηγούσαν σε ένα καλύτερο αποτέλεσμα αλλά θα ξέφευγε από τα όρια της εργασίας αυτής. / --

Approved for public release; distribution is unlimited / The contribution of this thesis is the development of a CAD (computer aided design) tool for current mode multiple-valued logic (MVL) CMOS circuits. It is only the second known MVL CAD tool and the first CAD tool for MVL CMOS. The tool accepts a specification of the function to be realized by the user, produces a minimal or near-minimal realization (if such a realization is possible), and produces a layout of a programmable logic array (PLA) integrated circuit that realizes the given function. The layout is in MAGIC format, suitable for submission to a chip manufacturer. The CAD tool also allows the user to simulate the realized function so that he/she can verify correctness of design. The CAD tool is designed also to be an analysis tool for heuristic minimization algorithms. As part of this thesis, a random function generator and statistics gathering package were developed. In the present tool, two heuristics are provided and the user can choose one or both. In the latter case, the better realization is output to the user. The CAD tool is designed to be flexible, so that future improvements can be made in the heuristic algorithms, as well as the layout generator. Thus, the tool can be used to accommodate new technologies, for example, a voltage mode CMOS PLA rather than the current mode CMOS currently implemented. / http://archive.org/details/cadtoolforcurren00leeh / Lieutenant, Republic of Korea Navy

Les travaux présentés dans ce mémoire de thèse s'intéressent à la validation fonctionnelle de contrôleurs logiques par des techniques de test de conformité et de validation en boucle fermée. Le modèle de spécification est décrit dans le langage industriel Grafcet et le contrôleur logique est supposé être un automate programmable industriel (API) mono-tâche. Afin de contribuer à ces techniques de validation fonctionnelle, ces travaux présentent : - Une extension d'une méthode de formalisation du Grafcet par traduction sous la forme d'une machine de Mealy. Cette extension permet de produire un modèle formel de la spécification lorsque le Grafcet est implanté selon un mode d'interprétation sans recherche de stabilité, qui n'est pas préconisé dans la norme IEC 60848 mais largement utilisé dans les applications industrielles. - Une contribution au test de conformité par la définition d'un ensemble de relations de conformité basées sur l'observation de plusieurs cycles d'exécution pour chaque pas de test. - Une contribution à la validation en boucle fermée par la définition d'un critère de fin d'observation et par une technique d'identification en boite grise pour la construction et l'analyse du système en boucle fermée. / The results presented in this PhD thesis deal with functional validation of logic controllers using conformance test and closed-loop validation techniques. The specification model is written in the Grafcet language and the logic controller is assumed to be a Programmable Logic Controller (PLC). In order to contribute to these validation techniques, this thesis presents: - An axtension to a fomalization methods for Grafcet languages by translation to a Mealy machine. This extension generates a formal model of a Grafcet specification that is interpreted without search of stability. This mode of interpretation is not recommended by the standard IEC 60848 but is widely used in industrial applications. - A contribution to conformance test by a definition of a set of conformance relation based on the observation of several execution cycles for each test step. - A contribution to closed-loop validation by the definition of a termination criterion and by a new gray-box identification technique that is used for construction and analysis of the closed-loop system.

Sistemas de controle fuzzy são amplamente empregados na indústria de controle de processos. Normalmente controlando variáveis analógicas, tais como pressão, temperatura, vazão, posição e velocidade. Hoje existem diversas soluções de mercado que permitem o uso da lógica fuzzy em CPs (Controladores programáveis). Porém essas soluções são proprietárias e de custo elevado. Adicionalmente existe a norma IEC 61131-7, introduzida no ano de 2000, que especifica sistemas fuzzy em CPs, onde a mesma define um conjunto de regras que permite a definição de algoritmos fuzzy independente do hardware de um fabricante de CPs. A adoção da norma IEC 61131-7 não vem acontecendo de uma maneira rápida, devido a diversos fatores, mas principalmente, por já existirem soluções proprietárias e personalizadas fornecidas pelos fabricantes de CPs. Portanto, a contribuição deste trabalho é um método de desenvolvimento de controladores fuzzy por retroalimentação usando como solução um sistema de código aberto ou livre. Este método propõe o uso de uma arquitetura de controle distribuído envolvendo PCs (Computadores pessoais) e CPs. A construção do controlador fuzzy foi feita em linguagem Java e liberada sobre licença de código aberto, assim permitindo o seu uso de forma gratuita em uma grande variedade de aplicações industriais. O método é baseado na norma IEC 61131-7 para a aplicação da lógica fuzzy em sistemas de automação industrial. Diversos testes foram realizados, tais como testes de mesa do software de controle, e até em uma planta real para validação de software de controle em operação real. Com os resultados dos testes foram obtidas diversas curvas de resposta no tempo, que permitem a avaliação do controlador e do software de controle. Após a execução dos testes e verificado o comportamento obtido pelas curvas, foi constatada a compatibilidade do software construído com a norma IEC 61131-7, assim permitindo o seu uso em outras aplicações. / Fuzzy control systems are largely applied at the processes control industry, usually controlling analogic variables, such as, pressure, temperature, outflow, position and speed. Nowadays, there are several market solutions which allow the Fuzzy Logic usage in PLCs (Programmable Logic Controllers), therefore, these solutions are proprietary and have a high cost. Additionally, there is the IEC 61131-7 standard, introduced in 2000, which specifies Fuzzy systems in PLCs. It defines a set of rules which allow the Fuzzy definition regardless of the hardware from the PLCs manufacturer. The adoption of the IEC 61131-7 standard is not happening effectively, due to many factors, but mainly because there are already proprietary and customized solutions provided by the PLCs manufacturers. The contribution provided by this report, is a method of Fuzzy control development by feedback using as solution, a free or open source code system. This method proposes the usage of a distributed control architecture involving both PCs (Personal Computers) and PLCs. The building of the Fuzzy controller was made in Java language and released under open source code license, allowing its use to be free in a great variety of industrial applications. The method is based on the IEC 61131-7 standard for the Fuzzy logic application in industrial automation. Several tests were performed, such as, software control table test, and even in a real plant for control software validation in a real operation. With the tests results were obtained quite a few response curves at time, which allow the evaluation of the controller and of the control software. After the tests executions and the verifying of the behavior obtained by the curves, it was stated the compatibility of the built software with the IEC 61131-7 standard, admitting it to be used in other applications.

Sistemas de controle fuzzy são amplamente empregados na indústria de controle de processos. Normalmente controlando variáveis analógicas, tais como pressão, temperatura, vazão, posição e velocidade. Hoje existem diversas soluções de mercado que permitem o uso da lógica fuzzy em CPs (Controladores programáveis). Porém essas soluções são proprietárias e de custo elevado. Adicionalmente existe a norma IEC 61131-7, introduzida no ano de 2000, que especifica sistemas fuzzy em CPs, onde a mesma define um conjunto de regras que permite a definição de algoritmos fuzzy independente do hardware de um fabricante de CPs. A adoção da norma IEC 61131-7 não vem acontecendo de uma maneira rápida, devido a diversos fatores, mas principalmente, por já existirem soluções proprietárias e personalizadas fornecidas pelos fabricantes de CPs. Portanto, a contribuição deste trabalho é um método de desenvolvimento de controladores fuzzy por retroalimentação usando como solução um sistema de código aberto ou livre. Este método propõe o uso de uma arquitetura de controle distribuído envolvendo PCs (Computadores pessoais) e CPs. A construção do controlador fuzzy foi feita em linguagem Java e liberada sobre licença de código aberto, assim permitindo o seu uso de forma gratuita em uma grande variedade de aplicações industriais. O método é baseado na norma IEC 61131-7 para a aplicação da lógica fuzzy em sistemas de automação industrial. Diversos testes foram realizados, tais como testes de mesa do software de controle, e até em uma planta real para validação de software de controle em operação real. Com os resultados dos testes foram obtidas diversas curvas de resposta no tempo, que permitem a avaliação do controlador e do software de controle. Após a execução dos testes e verificado o comportamento obtido pelas curvas, foi constatada a compatibilidade do software construído com a norma IEC 61131-7, assim permitindo o seu uso em outras aplicações. / Fuzzy control systems are largely applied at the processes control industry, usually controlling analogic variables, such as, pressure, temperature, outflow, position and speed. Nowadays, there are several market solutions which allow the Fuzzy Logic usage in PLCs (Programmable Logic Controllers), therefore, these solutions are proprietary and have a high cost. Additionally, there is the IEC 61131-7 standard, introduced in 2000, which specifies Fuzzy systems in PLCs. It defines a set of rules which allow the Fuzzy definition regardless of the hardware from the PLCs manufacturer. The adoption of the IEC 61131-7 standard is not happening effectively, due to many factors, but mainly because there are already proprietary and customized solutions provided by the PLCs manufacturers. The contribution provided by this report, is a method of Fuzzy control development by feedback using as solution, a free or open source code system. This method proposes the usage of a distributed control architecture involving both PCs (Personal Computers) and PLCs. The building of the Fuzzy controller was made in Java language and released under open source code license, allowing its use to be free in a great variety of industrial applications. The method is based on the IEC 61131-7 standard for the Fuzzy logic application in industrial automation. Several tests were performed, such as, software control table test, and even in a real plant for control software validation in a real operation. With the tests results were obtained quite a few response curves at time, which allow the evaluation of the controller and of the control software. After the tests executions and the verifying of the behavior obtained by the curves, it was stated the compatibility of the built software with the IEC 61131-7 standard, admitting it to be used in other applications.

Este trabalho apresenta uma Análise sobre os Comandos Numéricos Computadorizados de Arquitetura Aberta aplicado na automação de Máquina-ferramentas e no uso da manufatura. É realizado uma classificação das Arquiteturas Abertas (em relação ao hardware, software, funcionalidade e flexibilidade) e uma comparação entre os CNC\'s convencionais e os CNC\'s de Arquitetura Aberta. / This work presents an Open Architecture CNCs analysis. An Open Architecture classification using hardware, software, functionality and flexibility are presented. A comparison table with conventional CNCs and this new class of CNCs are elaborated.

Os sistemas produtivos (SPs) podem utilizar controladores programáveis (CPs) como dispositivos de realização do controle. Neste contexto, programas de controle executados por estes CPs podem ser desenvolvidos de forma que não estejam em conformidade com as especificações de projeto, o que poderá provocar o surgimento de erros funcionais associados à execução de tais programas de controle, erros estes que podem levar os SPs sob controle a um estado que poderá implicar em acidentes envolvendo equipamentos, pessoas e o meio-ambiente. Esta questão tem motivado o surgimento de diversas abordagens para identificar a existência de erros em programas de controle de CPs, de forma a permitir a correção destes erros e garantir, conseqüentemente, maior confiabilidade operacional. O presente trabalho tem por objetivo identificar a existência de erros em programas de controle baseados em LD (Ladder Diagram). Para isto, propõe-se um procedimento de desenvolvimento de modelos baseados em máquinas de estados finitos estendidas (MEFEs), que são gerados a partir do mapeamento de cada um dos rungs contidos no programa de controle que se deseja identificar erros. Uma vez desenvolvidos os modelos em MEFEs, torna-se possível a utilização de uma ferramenta computacional de verificação, própria para estabelecer se os modelos verificados satisfazem determinadas proposições estabelecidas em lógica temporal. Uma proposição em lógica temporal está relacionada a um estado específico do programa de controle modelado, sendo que o objetivo da verificação é o de estabelecer se a proposição estipulada é atendida ou não. Se um determinado estado específico for, por exemplo, um estado indesejado do programa de controle modelado, e este estado for possível de ser alcançado como resultado do processo de verificação realizado, isto impactará na não conformidade do programa de controle com as especificações comportamentais estipuladas na forma de proposição em lógica temporal, indicando haver, portanto, um erro neste programa de controle modelado. Palavras-chave: Controladores programáveis. Linguagem de programação LD. Modelagem e verificação de máquinas de estados finitos estendidas (MEFEs). / Productive systems (PS) can use programmable logic controllers (PLCs) as the devices of accomplishment of the control. In this context, control programs executed by these PLCs can be developed in a way so that they can be in non-conformity with the project specifications, and this fact may result in functional errors related to the control programs execution. These errors can take the PS under control to a state which can lead into accidents involving equipment, people and the environment. This fact has motivated the appearance of different approaches so as to identify the existence of these errors in PLC control programs so that they can be corrected and assure a greater operational reliability. This work aims at identifying the existence of errors in control programs based on Ladder Diagram (LD). In order to accomplish that, a modeling procedure that generates extended finite state machines (EFSMs) is proposed from the mapping of each one of the rungs in the control program whose errors are to be identified. Once the models based on EFSMs are developed it becomes possible to use a computational verification tool, specifically designed to determine if the verified models fulfill determined propositions established in temporal logic. A proposition in temporal logic is related to a specific state of the modeled control program and the objective of the verification is to establish whether the proposition is fulfilled or not. If a determined specific state, for example, is an unwanted state of the modeled control program and if this state is reachable as a result of the verification process, this will impact in the non-conformity of the control program with the behavior specifications established in a temporal logic proposition, indicating an error in this modeled control program.