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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Alternate Fault testing on a Bus on a Dynamic Position Vessel

Moorman, Anna Julia 18 September 2015 (has links)
Direct fault testing onboard Dynamic Position Vessels is a requirement to maintain the ships classification and ensure redundancy of the power system onboard to maintain position. The most vulnerable part of the ship when testing occurs is when a three phase fault is placed on a main bus. This puts tremendous amount of strain on the system. This thesis offers an alternate and safer way to ensure the protection equipment is working properly by using a fault signal using from Programmable Logic Controller in conjunction with the protection relays. A working PSCAD model of Transocean's DEEPWATER CHAMPION was developed using a one line diagram. Using the developed PSCAD model three phase fault currents could be calculated and then simulated as a scaled down secondary current to use for testing the protection relays. To test the develop testing system different bus configurations were analyzed to determine loss of thruster capabilities which deter the vessel to maintain position. / Master of Science
2

Safety Verification of Material Handling Systems Driven by Programmable Logic Controller : Consideration of Physical Behavior of Plants

OKUMA, Shigeru, SUZUKI, Tatsuya, KONAKA, Eiji 01 April 2004 (has links)
No description available.
3

Optimal Design of Sensor Parameters in PLC-Based Control System Using Mixed Integer Programming

OKUMA, Shigeru, SUZUKI, Tatsuya, MUTOU, Takashi, KONAKA, Eiji 01 April 2005 (has links)
No description available.
4

Automatická montáž a testování klíčků do zapalování automobilů / Automatic line for asembling and testing car key

Ščerba, Radek January 2010 (has links)
Main topic of this master's thesis is proposal of automatic line for bulding and testing keys for electrical ignition of cars. In the first part of this master's thesis you can see options of layout machines and proposal of two layouts. In this part you can see all actuators and senzors with detailed description of using in application, too. Next part is about software, communication between each components and description of visualization. Last part is about recapitulate of topic and evaluation building of machines with ideas for improvement this line for future.
5

Design and implementation of a programmable logic controller lab: An internet based monitoring and control of a process

Imaev, Aleksey January 2002 (has links)
No description available.
6

Controls development for the pallet handling device

Ottersbach, John Joseph January 1999 (has links)
No description available.
7

Attacking the Manufacturing Execution System : Leveraging a Programmable Logic Controller on the Shop Floor

Johansson, Fredrik January 2019 (has links)
Background. Automation in production has become a necessity for producing companies to keep up with the demand created by their customers. One way to automate a process is to use a piece of hardware called a programmable logic controller (PLC). A PLC is a small computer capable of being programmed to process a set of inputs, from e.g. sensors, and create outputs, to e.g. actuators, from that. This eliminates the risk of human errors while at the same time speeding up the production rate of the now near identical products. To improve the automation process on the shop floor and the production process in general a special software system is used. This system is known as the manufacturing execution system (MES), and it is connected to the PLCs and other devices on the shop floor. The MES have different functionalities and one of these is that it can manage instructions. Theses instructions can be aimed to both employees and devices such as the PLCs. Would the MES suffer from an error, e.g. in the instructions sent to the shop floor, the company could suffer from a negative impact both economical and in reputation. Since the PLC is a computer and it is connected to the MES it might be possible to attack the system using the PLC as leverage. Objectives. Examine if it is possible to attack the MES using a PLC as the attack origin. Methods. A literature study was performed to see what types of attacks and vulnerabilities that has been disclosed related to PLCs between 2010 and 2018. Secondly a practical experiment was done, trying to perform attacks targeting the MES. Results. The results are that there are many different types of attacks and vulnerabilities that has been found related to PLCs and the attacks done in the practical experiment failed to induce negative effects in the MES used. Conclusions. The conclusion of the thesis is that two identified PLC attack techniques seems likely to be used to attack the MES layer. The methodology that was used to attack the MES layer in the practical experiment failed to affect the MES in a negative way. However, it was possible to affect the log file of the MES in one of the test cases. So, it does not rule out that other MES types are not vulnerable or that the two PLC attacks identified will not work to affect the MES. / Bakgrund. Automatisering inom produktion har blivit nödvändigt för att företag ska kunna tillgodose den efterfrågan som deras kunder skapar. Ett sätt att automatisera denna process är genom att använde en typ av hårdvara som på engelska kallas för programmable logic controller (PLC). En PLC är en liten dator som man kan programmera så att den bearbetar signaler in, från t.ex. sensorer, och skapar signaler ut, till t.ex. motorer, från det. Detta eliminerar då risken för mänskliga fel samtidigt som det snabbar upp produktionen av de nu nästan identiska produkterna. För att förbättra automatiseringsprocessen på golvet i fabrikerna och även tillverkningsprocessen generellt så används ett speciellt mjukvarusystem. Detta system kallas på engelska execution manufacturing system (MES), och detta system är kopplat till PLCerna och annan utrustning på produktionsgolvet. MESen har olika funktionaliteter och en utav dessa är hantering av instruktioner. Dessa instruktioner kan vara riktade både till anställda samt utrustning så som PLCer. Skulle det inträffa ett fel i MESen, t.ex. i instruktionerna som skickas till produktionsgolvet, så skulle företaget kunna få lida av negativa konsekvenser både ekonomiskt och för företagets rykte. I och med att en PLC är en dator och den är kopplad till MES så kan det finnas möjligheter att utföra attacker mot MESen genom att använda en PLC som utgångspunkt. Syfte. Undersöka om det är möjligt att utföra en attack på en MES med utgångspunkt från en PLC. Metod. En litteraturstudie genomfördes för att ta reda på vilka typer av attacker samt sårbarheter relaterade till PLCer som publicerats mellan 2010 och 2018. Ett praktiskt experiment utfördes också, där attackförsök gjordes på ett MES. Resultat. Resultatet är att det finns många olika attacktyper samt sårbarheter som upptäckts relaterade till PLCer och att de attacker som utfördes i det praktiska experimentet inte lyckades skapa några negativa effekter i det MES som användes. Slutsatser. Slutsatsen för examensarbetet är att två olika typer av de hittade PLC-attackerna verkar vara kapabla till att användas för att attackera MES-lagret. Metoden som användes i det praktiska försöket lyckades inte påverka MES-lagret negativt. Men det gick att påverka MESens logfil i ett av testfallen, så det går inte att fastslå att andra MES-typer inte är sårbara mot detta eller att de två identifierade PLC-attackerna inte kommer kunna påverka MES-lagret negativt.
8

Design and Control of Trailer Based Shopping Cart Washing System

Jiacheng, Cai, Chunhong, Yang, Cenan, Chen January 2016 (has links)
The shopping trolley have been frequently used in our daily life. However, the hygiene condition of cart makes people worry a lot, especially the handle brothers. Nowadays, several methods have been proposed to clean the shopping carts but considered uneconomic and inflexible. In this study, we aim to design an integrated cart washing system based on a trailer applied to medium or small supermarket. This system should be more efficient, economic, easily to operate, safer and les water consummation. The integrated cart washing system has three basic functions of washing, disinfection and drying. The system is controlled by PLC program, all steps in the cleaning process are fully automatic insider the trailer and each component are adjustable according to various shopping carts. The system only requires one person to operate and it costs 30 seconds to wash a single cart, able to wash up to 120 cart/hour. Disinfection and drying steps provide high washing quality. Moreover, water-recycling design can save part of wasted water. The modelling and assembly was designed in Autodesk Inventor 2016, the hardware design circuit-writing diagram was performed in AutoCAD, the software design of Programmable logic controller (PLC) was made in STEP 7-Micro/Win. Theoretical calculation and simulation prove the safety and possibility of our system. We concluded that this system might have commercial interests in the market.
9

Black-Box identification of automated discrete event systems / Identification "boîte-noire" des systèmes automatisés à événements discrets

Estrada Vargas, Ana Paula 20 February 2013 (has links)
Cette thèse traite de l'identification des systèmes à événements discrets (SED) automatisés dans un contexte industriel. En particulier, le travail aborde les systèmes formés par un processus et un automate programmable (AP) fonctionnant en boucle fermée - l'identification a pour but d’obtenir un modèle approximatif exprimé en réseaux de Petri interprétés (RPI) à partir du comportement externe observé sous la forme d'une seule séquence de vecteurs d’entrée-sortie de l’AP. Tout d'abord, une analyse des méthodes d'identification est présentée, ainsi qu’une étude comparative des méthodes récentes pour l'identification des SED. Puis le problème abordé est décrit - des importantes caractéristiques technologiques dans les systèmes automatisés par l’AP sont détaillées. Ces caractéristiques doivent être prises en compte dans la résolution du problème, mais elles ne peuvent pas être traitées par les méthodes existantes d’identification. La contribution principale de cette thèse est la création de deux méthodes d’identification complémentaires. La première méthode permet de construire systématiquement un modèle RPI à partir d'une seule séquence entrée-sortie représentant le comportement observable du SED. Les modèles RPI décrivent en détail l’évolution des entrées et sorties pendant le fonctionnement du système. La seconde méthode considère des SED grands et complexes - elle est basée sur une approche statistique qui permettre la construction des modèles en RPI compactes et expressives. Elle est composée de deux étapes - la première calcule à partir de la séquence entrée-sortie, la partie réactive du modèle, constituée de places observables et de transitions. La deuxième étape fait la construction de la partie non-observable, en rajoutant des places pour permettre la reproduction de la séquence entrée-sortie. Les méthodes proposées, basées sur des algorithmes de complexité polynomiale, ont été implémentées en outils logiciels, lesquels ont été testés avec des séquences d’entrée-sortie obtenues à partir des systèmes réels en fonctionnement. Les outils sont décrits et leur application est illustrée à travers deux cas d’étude. / This thesis deals with the identification of automated discrete event systems (DES) operating in an industrial context. In particular the work focuses on the systems composed by a plant and a programmable logic controller (PLC) operating in a closed loop- the identification consists in obtaining an approximate model expressed in interpreted Petri nets (IPN) from the observed behaviour given under the form of a single sequence of input-output vectors of the PLC. First, an overview of previous works on identification of DES is presented as well as a comparative study of the main recent approaches on the matter. Then the addressed problem is stated- important technological characteristics of automated systems and PLC are detailed. Such characteristics must be considered in solving the identification problem, but they cannot be handled by previous identification techniques. The main contribution in this thesis is the creation of two complementary identification methods. The first method allows constructing systematically an IPN model from a single input-output sequence representing the observable behaviour of the DES. The obtained IPN models describe in detail the evolution of inputs and outputs during the system operation. The second method has been conceived for addressing large and complex industrial DES- it is based on a statistical approach yielding compact and expressive IPN models. It consists of two stages- the first one obtains, from the input-output sequence, the reactive part of the model composed by observable places and transitions. The second stage builds the non observable part of the model including places that ensure the reproduction of the observed input-output sequence. The proposed methods, based on polynomial-time algorithms, have been implemented in software tools, which have been tested with input-output sequences obtained from real systems in operation. The tools are described and their application is illustrated through two case studies.
10

Semantic-aware Stealthy Control Logic Infection Attack

kalle, Sushma 06 August 2018 (has links)
In this thesis work we present CLIK, a new, automated, remote attack on the control logic of a programmable logic controller (PLC) in industrial control systems. The CLIK attack modifies the control logic running in a remote target PLC automatically to disrupt a physical process. We implement the CLIK attack on a real PLC. The attack is initiated by subverting the security measures that protect the control logic in a PLC. We found a critical (zero-day) vulnerability, which allows the attacker to overwrite password hash in the PLC during the authentication process. Next, CLIK retrieves and decompiles the original logic and injects a malicious logic into it and then, transfers the infected logic back to the PLC. To hide the infection, we propose a virtual PLC that engages the software the virtual PLC intercepts the request and then, responds with the original (uninfected) control logic to the software.

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