504 research outputs found

    Supervisory Control Systems: Theory and Industrial Applications

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    Hybrid control system is an exciting field of research where it contains two distinct types of systems: one with continuous dynamics continuous variable dynamic system and the other with discrete dynamics discrete event dynamic system, that interact with each other. The research in the area of hybrid control can be categorized into two areas: one deals with the conventional control systems, and the other deals with the decision making systems. The former addresses the control functions at the low level (field level). The latter addresses the modeling, analysis, and design at the higher level found in the supervision, coordination and management levels. The study of hybrid systems is central in designing intelligent hybrid control systems with high degree of autonomy and it is essential in designing discrete event supervisory controllers for continuous systems

    Design and Simulation of a Supervisory Control System for Hybrid Manufacturing

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    The research teams of Dr. Bill Hamel, Dr. Bradley Jared and Dr. Tony Schmitz were tasked by the Office of Naval Research to create a hybrid manufacturing process for a reduced scale model of a naval ship propeller. The base structure of the propeller is created using Wire Arc Additive Manufacturing (WAAM), which is then scanned to compare created geometry to desired geometry. The propeller is then machined down to match the desired geometry. This process is iterated upon until the final product meets design tolerances. Due to the complex nature and numerous industrial machines used in the process, it is desirable to create a control system for Supervisory Control and Data Acquisition (SCADA). This supervisory control system is necessary in order to ensure safe operations and logging of system data to document successful trials. The goal of this thesis is to outline the design and simulation of a supervisory control system for this hybrid manufacturing cell. The design and implementation is focused on a simulation of the control of relevant boolean states of the system. This is accomplished through a Human Machine Interface (HMI) created in LabVIEW accompanied by appropriate data flow diagrams, models and communication specifications between machines. The creation of a digital twin of this hybrid manufacturing system was successful and useful in the implementation of physical components

    A graphical environment and applications for discrete event and hybrid systems in robotics and automation

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    technical reportIn this paper we present an overview for the development of a graphical environment for simulating, analyzing, synthesizing, monitoring, and controlling complex discrete event and hybrid systems within the robotics, automation, and intelligent system domain. We start by presenting an overview of discrete event and hybrid systems, and then discuss the proposed framework. We also present two applications within the robotics and automation domain for such complex systems. The first is for formulating an observer for manipulating agents, and the second is for designing sensing strategies for the inspection of machine parts

    Optimal and intelligent decision making in sustainable development of electronic products

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    Increasing global population and consumption are causing declining natural and social systems. Multi-lifecycle engineering and sustainable development address these issues by integrating strategies for economic successes, environmental quality, and social equity. Based on multi-lifecycle engineering and sustainable development concepts, this doctoral dissertation aims to provide decision making approaches to growing a strong industrial economy while maintaining a clean, healthy environment. The research develops a methodology to complete both the disassembly leveling and bin assignment decisions in demanufacturing through balancing the disassembly efforts, value returns, and environmental impacts. The proposed method is successfully implemented into a demanufacturing module of a Multi-LifeCycle Assessment and Analysis tool. The methodology is illustrated by a computer product example. Since products during the use stage may experience very different conditions, their external and internal status can vary significantly. These products, when coming to a demanufacturing facility, are often associated with incomplete/imprecise information, which complicates demanufacturing process decision making. In order to deal with uncertain information, this research proposes Fuzzy Reasoning Petri nets to model and reason knowledge-based systems and successfully applies them to demanufacturing process decision making to obtain the maximal End-of-Life (BOL) value from discarded products. Besides the BOL management of products by means of product/material recovery to decrease environmental impacts, the concepts of design for environment and sustainable development are investigated. Based on Sustainability Target Method, a sensitivity analysis decision-making method is proposed. It provides a company with suggestions to improve its product\u27s sustainability in the most cost-effective manner

    Process control and configuration of a reconfigurable production system using a multi-agent software system

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    Thesis (M. Tech. (Information Technology)) -- Central University of technology, Free State, 2011Traditional designs for component-handling platforms are rigidly linked to the product being produced. Control and monitoring methods for these platforms consist of various proprietary hardware controllers containing the control logic for the production process. Should the configuration of the component handling platform change, the controllers need to be taken offline and reprogrammed to take the changes into account. The current thinking in component-handling system design is the notion of re-configurability. Reconfigurability means that with minimum or no downtime the system can be adapted to produce another product type or overcome a device failure. The re-configurable component handling platform is built-up from groups of independent devices. These groups or cells are each responsible for some aspect of the overall production process. By moving or swopping different versions of these cells within the component-handling platform, re-configurability is achieved. Such a dynamic system requires a flexible communications platform and high-level software control architecture to accommodate the reconfigurable nature of the system. This work represents the design and testing of the core of a re-configurable production control software platform. Multiple software components work together to control and monitor a re-configurable component handling platform. The design and implementation of a production database, production ontology, communications architecture and the core multi-agent control application linking all these components together is presented

    Modeling and formal verification of probabilistic reconfigurable systems

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    In this thesis, we propose a new approach for formal modeling and verification of adaptive probabilistic systems. Dynamic reconfigurable systems are the trend of all future technological systems, such as flight control systems, vehicle electronic systems, and manufacturing systems. In order to meet user and environmental requirements, such a dynamic reconfigurable system has to actively adjust its configuration at run-time by modifying its components and connections, while changes are detected in the internal/external execution environment. On the other hand, these changes may violate the memory usage, the required energy and the concerned real-time constraints since the behavior of the system is unpredictable. It might also make the system's functions unavailable for some time and make potential harm to human life or large financial investments. Thus, updating a system with any new configuration requires that the post reconfigurable system fully satisfies the related constraints. We introduce GR-TNCES formalism for the optimal functional and temporal specification of probabilistic reconfigurable systems under resource constraints. It enables the optimal specification of a probabilistic, energetic and memory constraints of such a system. To formally verify the correctness and the safety of such a probabilistic system specification, and the non-violation of its properties, an automatic transformation from GR-TNCES models into PRISM models is introduced. Moreover, a new approach XCTL is also proposed to formally verify reconfigurable systems. It enables the formal certification of uncompleted and reconfigurable systems. A new version of the software ZIZO is also proposed to model, simulate and verify such GR-TNCES model. To prove its relevance, the latter was applied to case studies; it was used to model and simulate the behavior of an IPV4 protocol to prevent the energy and memory resources violation. It was also used to optimize energy consumption of an automotive skid conveyor.In dieser Arbeit wird ein neuer Ansatz zur formalen Modellierung und Verifikation dynamisch rekonfigurierbarer Systeme vorgestellt. Dynamische rekonfigurierbare Systeme sind in vielen aktuellen und zukünftigen Anwendungen, wie beispielsweise Flugsteuerungssystemen, Fahrzeugelektronik und Fertigungssysteme zu finden. Diese Systeme weisen ein probabilistisches, adaptives Verhalten auf. Um die Benutzer- und Umgebungsbedingungen kontinuierlich zu erfüllen, muss ein solches System seine Konfiguration zur Laufzeit aktiv anpassen, indem es seine Komponenten, Verbindungen zwischen Komponenten und seine Daten modifiziert (adaptiv), sobald Änderungen in der internen oder externen Ausführungsumgebung erkannt werden (probabilistisch). Diese Anpassungen dürfen Beschränkungen bei der Speichernutzung, der erforderlichen Energie und bestehende Echtzeitbedingungen nicht verletzen. Eine nicht geprüfte Rekonfiguration könnte dazu führen, dass die Funktionen des Systems für einige Zeit nicht verfügbar wären und potenziell menschliches Leben gefährdet würde oder großer finanzieller Schaden entstünde. Somit erfordert das Aktualisieren eines Systems mit einer neuen Konfiguration, dass das rekonfigurierte System die zugehörigen Beschränkungen vollständig einhält. Um dies zu überprüfen, wird in dieser Arbeit der GR-TNCES-Formalismus, eine Erweiterung von Petrinetzen, für die optimale funktionale und zeitliche Spezifikation probabilistischer rekonfigurierbarer Systeme unter Ressourcenbeschränkungen vorgeschlagen. Die entstehenden Modelle sollen über probabilistische model checking verifiziert werden. Dazu eignet sich die etablierte Software PRISM. Um die Verifikation zu ermöglichen wird in dieser Arbeit ein Verfahren zur Transformation von GR-TNCES-Modellen in PRISM-Modelle beschrieben. Eine neu eingeführte Logik (XCTL) erlaubt zudem die einfache Beschreibung der zu prüfenden Eigenschaften. Die genannten Schritte wurden in einer Softwareumgebung für den automatisierten Entwurf, die Simulation und die formale Verifikation (durch eine automatische Transformation nach PRISM) umgesetzt. Eine Fallstudie zeigt die Anwendung des Verfahren

    Modeling, design and scheduling of computer integrated manufacturing and demanufacturing systems

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    This doctoral dissertation work aims to provide a discrete-event system-based methodology for design, implementation, and operation of flexible and agile manufacturing and demanufacturing systems. After a review of the current academic and industrial activities in these fields, a Virtual Production Lines (VPLs) design methodology is proposed to facilitate a Manufacturing Execution System integrated with a shop floor system. A case study on a back-end semiconductor line is performed to demonstrate that the proposed methodology is effective to increase system throughput and decrease tardiness. An adaptive algorithm is proposed to deal with the machine failure and maintenance. To minimize the environmental impacts caused by end-of-life or faulty products, this research addresses the fundamental design and implementation issues of an integrated flexible demanufacturing system (IFDS). In virtue of the success of the VPL design and differences between disassembly and assembly, a systematic approach is developed for disassembly line design. This thesis presents a novel disassembly planning and demanufacturing scheduling method for such a system. Case studies on the disassembly of personal computers are performed illustrating how the proposed approaches work

    Recent Advances in Multi Robot Systems

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    To design a team of robots which is able to perform given tasks is a great concern of many members of robotics community. There are many problems left to be solved in order to have the fully functional robot team. Robotics community is trying hard to solve such problems (navigation, task allocation, communication, adaptation, control, ...). This book represents the contributions of the top researchers in this field and will serve as a valuable tool for professionals in this interdisciplinary field. It is focused on the challenging issues of team architectures, vehicle learning and adaptation, heterogeneous group control and cooperation, task selection, dynamic autonomy, mixed initiative, and human and robot team interaction. The book consists of 16 chapters introducing both basic research and advanced developments. Topics covered include kinematics, dynamic analysis, accuracy, optimization design, modelling, simulation and control of multi robot systems

    Modeling, Simulation, and Realization of Cognitive Technical Systems

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    This thesis presents a novel approach for the modeling, simulation, and realization of Cognitive Technical Systems. In contrast to other approaches, in this thesis, the structure and dynamic of the real world is initially formalized my means of an intermediate level instead of implementing a technical model directly. Furthermore, human cognition is investigated in an integrated manner and based on experiments with a mobile robot, as an example for a complex technical system. The formal description of human interaction and cognition is realized by Situation-Operator-Modeling (SOM), which can be implemented technically by patterns of high-level Petri Nets. With the state space of a SOM-based Petri Net, Human-Machine-Interaction can be analyzed, e.g., in order to detect human errors automatically. Furthermore, several cognitive functions, like planning, execution, perception, and learning, can be simulated. The different cognitive functions and related representations, which are all based on the same methodical background, are combined within an integrated cognitive architecture. Only the interplay among several functions and a novel kind of knowledge structuring, which contributes significantly to reduce the complexity of the real world, enable the realization of human-like behavior for technical systems. The system's capability to establish and to refine goal-directed behavior from interaction with the environment, also if no system-specific initial knowledge is available, is demonstrated by experiments with a mobile robot interacting within a dynamic office environment. An additional value of this thesis for further research is especially given by the proposed generic approach for modeling, simulation, and analysis of Human-Machine-Interaction. Moreover, the formal description and implementation of the cognitive functions, the developed knowledge structuring, and the cognitive architecture may be applied to arbitrary kind of technical systems.'Modellbildung, Simulation und Realisierung von Kognitiven Technischen Systemen' In dieser Arbeit wird ein neuartiger Ansatz zur Modellbildung, Simulation und Realisierung von Kognitiven Technischen Systemen präsentiert. Gegenüber bestehenden Ansätzen setzt sich diese Arbeit insbesondere dadurch ab, dass die Struktur und Dynamik der realen Welt zuerst über eine methodische Zwischenebene formal beschrieben und erst danach technisch implementiert wird. Zudem wird menschliche Kognition ganzheitlich untersucht und direkt mit Hilfe von Experimenten mit einem mobilen Roboter, als Beispiel für ein komplexes technisches System, erprobt und entwickelt. Die formale Beschreibung von menschlicher Interaktion und Kognition erfolgt über Situations-Operator-Modellbildung (SOM), welche über spezielle Muster höherer Petrinetze technisch implementiert werden kann. Durch den Zustandsraum eines SOM-basierten Petrinetzes ist es möglich, Mensch-Maschine-Interaktion zu analysieren, um beispielsweise menschliche Fehler automatisiert zu erfassen. Zudem können verschiedene kognitive Funktionen, wie Planen, Handeln, Wahrnehmung und Lernen simuliert werden. Die verschiedenen kognitiven Funktionen und entsprechenden Repräsentationen, welche auf der gleichen methodischen Grundlage basieren, werden in einer kognitiven Architektur zusammengeführt. Erst das Zusammenspiel verschiedener Funktionen und ein neuartiger Ansatz zur Wissensstrukturierung, wodurch insbesondere die Komplexität der realen Welt reduziert wird, ermöglicht die Realisierung menschenähnlichen Verhaltens für technische Systeme. Durch Experimente mit einem mobilen Roboter, der in einer dynamischen Büroumgebung interagiert, kann gezeigt werden, dass das vorgestellte System ohne anwendungsspezifisches Vorwissen in der Lage ist, zielführendes Verhalten aus der Interaktion mit der Umgebung zu erhalten und zu verbessern. Ein Mehrwert aus dieser Arbeit für weiterführende Forschungsarbeiten ergibt sich insbesondere durch den vorgestellten generischen Ansatz zur Modellbildung, Simulation und Analyse von Mensch-Maschine-Interaktion. Zudem können die formale Beschreibung und die Implementierung der kognitiven Funktionen, der entwickelten Wissensstrukturierung und der darauf aufbauenden kognitiven Architektur auf beliebige technische Systeme übertragen werden
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