Anpassen verteilter eingebetteter Anwendungen im laufenden Betrieb

The availability of third-party apps is among the key success factors for software ecosystems: The users benefit from more features and innovation speed, while third-party solution vendors can leverage the platform to create successful offerings. However, this requires a certain decoupling of engineering activities of the different parties not achieved for distributed control systems, yet. While late and dynamic integration of third-party components would be required, resulting control systems must provide high reliability regarding real-time requirements, which leads to integration complexity. Closing this gap would particularly contribute to the vision of software-defined manufacturing, where an ecosystem of modern IT-based control system components could lead to faster innovations due to their higher abstraction and availability of various frameworks. Therefore, this thesis addresses the research question: How we can use modern IT technologies and enable independent evolution and easy third-party integration of software components in distributed control systems, where deterministic end-to-end reactivity is required, and especially, how can we apply distributed changes to such systems consistently and reactively during operation? This thesis describes the challenges and related approaches in detail and points out that existing approaches do not fully address our research question. To tackle this gap, a formal specification of a runtime platform concept is presented in conjunction with a model-based engineering approach. The engineering approach decouples the engineering steps of component definition, integration, and deployment. The runtime platform supports this approach by isolating the components, while still offering predictable end-to-end real-time behavior. Independent evolution of software components is supported through a concept for synchronous reconfiguration during full operation, i.e., dynamic orchestration of components. Time-critical state transfer is supported, too, and can lead to bounded quality degradation, at most. The reconfiguration planning is supported by analysis concepts, including simulation of a formally specified system and reconfiguration, and analyzing potential quality degradation with the evolving dataflow graph (EDFG) method. A platform-specific realization of the concepts, the real-time container architecture, is described as a reference implementation. The model and the prototype are evaluated regarding their feasibility and applicability of the concepts by two case studies. The first case study is a minimalistic distributed control system used in different setups with different component variants and reconfiguration plans to compare the model and the prototype and to gather runtime statistics. The second case study is a smart factory showcase system with more challenging application components and interface technologies. The conclusion is that the concepts are feasible and applicable, even though the concepts and the prototype still need to be worked on in future -- for example, to reach shorter cycle times.Eine große Auswahl von Drittanbieter-Lösungen ist einer der Schlüsselfaktoren für Software Ecosystems: Nutzer profitieren vom breiten Angebot und schnellen Innovationen, während Drittanbieter über die Plattform erfolgreiche Lösungen anbieten können. Das jedoch setzt eine gewisse Entkopplung von Entwicklungsschritten der Beteiligten voraus, welche für verteilte Steuerungssysteme noch nicht erreicht wurde. Während Drittanbieter-Komponenten möglichst spät -- sogar Laufzeit -- integriert werden müssten, müssen Steuerungssysteme jedoch eine hohe Zuverlässigkeit gegenüber Echtzeitanforderungen aufweisen, was zu Integrationskomplexität führt. Dies zu lösen würde insbesondere zur Vision von Software-definierter Produktion beitragen, da ein Ecosystem für moderne IT-basierte Steuerungskomponenten wegen deren höherem Abstraktionsgrad und der Vielzahl verfügbarer Frameworks zu schnellerer Innovation führen würde. Daher behandelt diese Dissertation folgende Forschungsfrage: Wie können wir moderne IT-Technologien verwenden und unabhängige Entwicklung und einfache Integration von Software-Komponenten in verteilten Steuerungssystemen ermöglichen, wo Ende-zu-Ende-Echtzeitverhalten gefordert ist, und wie können wir insbesondere verteilte Änderungen an solchen Systemen konsistent und im Vollbetrieb vornehmen? Diese Dissertation beschreibt Herausforderungen und verwandte Ansätze im Detail und zeigt auf, dass existierende Ansätze diese Frage nicht vollständig behandeln. Um diese Lücke zu schließen, beschreiben wir eine formale Spezifikation einer Laufzeit-Plattform und einen zugehörigen Modell-basierten Engineering-Ansatz. Dieser Ansatz entkoppelt die Design-Schritte der Entwicklung, Integration und des Deployments von Komponenten. Die Laufzeit-Plattform unterstützt den Ansatz durch Isolation von Komponenten und zugleich Zeit-deterministischem Ende-zu-Ende-Verhalten. Unabhängige Entwicklung und Integration werden durch Konzepte für synchrone Rekonfiguration im Vollbetrieb unterstützt, also durch dynamische Orchestrierung. Dies beinhaltet auch Zeit-kritische Zustands-Transfers mit höchstens begrenzter Qualitätsminderung, wenn überhaupt. Rekonfigurationsplanung wird durch Analysekonzepte unterstützt, einschließlich der Simulation formal spezifizierter Systeme und Rekonfigurationen und der Analyse der etwaigen Qualitätsminderung mit dem Evolving Dataflow Graph (EDFG). Die Real-Time Container Architecture wird als Referenzimplementierung und Evaluationsplattform beschrieben. Zwei Fallstudien untersuchen Machbarkeit und Nützlichkeit der Konzepte. Die erste verwendet verschiedene Varianten und Rekonfigurationen eines minimalistischen verteilten Steuerungssystems, um Modell und Prototyp zu vergleichen sowie Laufzeitstatistiken zu erheben. Die zweite Fallstudie ist ein Smart-Factory-Demonstrator, welcher herausforderndere Applikationskomponenten und Schnittstellentechnologien verwendet. Die Konzepte sind den Studien nach machbar und nützlich, auch wenn sowohl die Konzepte als auch der Prototyp noch weitere Arbeit benötigen -- zum Beispiel, um kürzere Zyklen zu erreichen

Internet of Things Software Modules Marketplace

The project developed is a centralised repository of software packages to be used in cyber-physical systems. It is composed by a central database, an http api, an ftp client to serve files and a web application to manage the repository. The system also communicates via OPCUA protocol with the embed-system for real time monitoring.The advent of the Cyber-Physical Systems (CPS), a physical system representation through a vir-tual model, usually used to control a system or a process comes from the growing democratizationof the computational power. Nowadays, virtually anything can be equipped with some kind ofembedded processor to automate tasks, generate or consume some kind of data. In addition, thecontinuous development and improvement of the communication networks has helped leveragethe concept of the Internet of Things (IoT) in which things are now, themselves, connected to theInternet, exchanging data with each other and with people.In the industrial sector, CPS, also called Cyber-Physical Production Systems (CPPS) and theIoT are the main technological advances that lead to the industry fourth revolution, common des-ignated as Industry 4.0 in which the factory floor is no longer a centralized model where all thecomputation is done centrally but is now a decentralized model where industrial equipment haveembedded devices to control, automate tasks and react in a dynamic and intelligent manner to thesensed physical environment.Thereby, one of the keywords around the CPPSs is software. Software is no longer centralizedand is now distributed through several devices that comprises the system. This new approachcomes with significant changes and one of them is the reuse and distribution of the software. Itis not viable to manual deploy and install software in hundreds or thousands of devices and nothaving a way of reusing the existing software. If, on the one hand, the desire is to develop a moreintelligent process control system, on the other, flexibility, adaptability and simplicity are alsoconvenient capabilities or else intelligent manufacturing process control systems are built upon alot of resources debt. Hence, the solution is to build standards, tools and frameworks that allowthe reuse of software and its rapid deployment in the distributed devices.One option, in the Industry 4.0 field, to cope with the software reuse issue in this kind of sys-tems is the encapsulation of software in functional blocks, the Function Blocks (FBs) and their usein the function block programming paradigm, described in IEC 61499 standard. The functionalityis abstracted away in the FBs and can be reused by just deploying the them to the devices. Thisway, it is easier to manage a network by dragging and dropping these blocks, building complexapplications centrally and deploy everything to the distributed embedded devices. However, theimplementation of this standard to address the aforementioned problem brings, itself, other neces-sities such as managing the FBs, monitoring them and their previous download by the embeddeddevices.This dissertation main goal is the development of a marketplace to manage and monitor of FBs in a IEC 61499 network envisioning the filling of the previous mentioned gaps in this kindof networks. The marketplace, integrated in a IEC 61499 global solution will not only enable thedistribution of FBs among the embedded devices in a IEC 61499 compliant CPPS but also manageFBs versions, functioning as a central repository of software components, having also monitoringand statistical features, allowing the detection of flaws or malfunctions and collect statistical datai iiabout FBs usage

Software Systems Engineering for Cyber Physical Production Systems

This project solves the problem of easy adaption and usage of CPPS by small scale industries, With this project it has been tried to develop a methodology of requirement engineering for CPPS system and finally the whole system. We have developed the approach right from requirement engineering to mapping into IEC61499 function blocks and then to deployment to a physical devices. This work can be a good foundation and support for scientific communities or industialist to easily implement requirement engineering of a small scale systems for CPPS and thus build a 21st century production system with this and reap its enormous benefits.Cyber physical production systems are the future of production systems not only in europe but in the entire world. It brings with itself huge benefits and popularly attributes to Industry 4.0 also. These are automated systems where physical systems are monitored and controlled by computer based algorithms in real time. Traditional systems have certain disadvantages and are limited in terms of hours of operation as it is governed by manpowers and the type of products that can be produced without making much changes in the production configuration and the speed of production of products. In europe, a lot of research is going on, particularly in germany and in the United states too for upgrading major physical systems and manufacturing systems. Some examples of such systems are smart factory, smart grid, autonomous automobile systems, automatic pilot avionics, robotics systems etc. The main goal of this thesis is to define a set of methodologies for easing the process of implementation of the CPPS(cyber physical production systems) system on small and medium industries so that the adoption rate for such industries can be high. There is no methodology yet particularly for CPPS systems for small and medium industries, although we have methodologies in place for large industries. In order to do so, first study was done for challenges in developing a requirement engineering process in section 3 and how it is different from a typical software system. An approach has been developed based on existing information available on large systems and CPPS and some software engineering frameworks like MODAF and TOGAF. A proposal for the process and some diagrams and tools has been made in section 4. To validate the proposed approach we have taken a synthetic test case of a pizza production system and implemented all the approaches to transform it into a cyber physical production system right from requirement and UML diagrams to the final function block approach. With this set of approaches,there is now a basis for software development methodology for small and medium industries particularly. With these approaches the adoption rate can be really high for such industries bringing out traditional industries more to the 21st century forefront

A component-based virtual engineering approach to PLC code generation for automation systems

In recent years, the automotive industry has been significantly affected by a number of challenges driven by globalisation, economic fluctuations, environmental awareness and rapid technological developments. As a consequence, product lifecycles are shortening and customer demands are becoming more diverse. To survive in such a business environment, manufacturers are striving to find a costeffective solution for fast and efficient development and reconfiguration of manufacturing systems to satisfy the needs of changing markets without losses in production. Production systems within automotive industry are vastly automated and heavily rely on PLC-based control systems. It has been established that one of the major obstacles in realising reconfigurable manufacturing systems is the fragmented engineering approach to implement control systems. Control engineering starts at a very late stage in the overall system engineering process and remains highly isolated from the mechanical design and build of the system. During this stage, control code is typically written manually in vendor-specific tools in a combination of IEC 61131-3 languages. Writing control code is a complex, time consuming and error-prone process. [Continues.

From Java to real-time Java : A model-driven methodology with automated toolchain

Real-time systems are receiving increasing attention with the emerging application scenarios that are safety-critical, complex in functionality, high on timing-related performance requirements, and cost-sensitive, such as autonomous vehicles. Development of real-time systems is error-prone and highly dependent on the sophisticated domain expertise, making it a costly process. There is a trend of the existing software without the real-time notion being re-developed to realise real-time features, e.g., in the big data technology. This paper utilises the principles of model-driven engineering (MDE) and proposes the first methodology that automatically converts standard time-sharing Java applications to real-time Java applications. It opens up a new research direction on development automation of real-time programming languages and inspires many research questions that can be jointly investigated by the embedded systems, programming languages as well as MDE communities

Agent-based manufacturing — review and expert evaluation

The advent of smart manufacturing and the exposure to a new generation of technological enablers have revolutionized the way manufacturing process is carried out. Cyber-Physical Production Systems (CPPS) are introduced as main actors of this manufacturing shift. They are characterized for having high levels of communication, integration and computational capabilities that led them to a certain level of autonomy. Despite the high expectations and vision of CPPS, it still remains an exploratory topic. Multi-Agent Systems (MAS) have been widely used by software engineers to solve traditional computing problems, e.g., banking transactions. Because of their high levels of distribution and autonomous capabilities, MAS have been considered by the research community as a good solution to design and implement CPPS. This work first introduces a collection of requirements and characteristics of smart manufacturing. A comprehensive review of various research applications is presented to understand the current state of the art and the application of agent technology in manufacturing. Considering the smart manufacturing requirements and current research application, a SWOT analysis was formulated which identifies pros and cons of the implementation of agents in industry. The SWOT analysis was further validated by an industrial expert evaluation and the main findings and discussion of the results are presented

OPTIMIZATION OF PRODUCTION LINES USING ADVANCED CNC INTERPOLATION METHODS AND DISTRIBUTION OF CONTROL LOGIC

These days, information technology really makes the difference in manufacturing industry. High performance computers allow to realize control algorithms of increasing complexity and high speed reliable computer networks allows the communication between different devices and realization of advanced distributed control applications. In this thesis, we focus on the optimization of the production lines using two different approaches. First we focus on the improvement of a single workstation of the production line, then we focus on the improvement of the interactions between various stations of the production line.. A typical workstation that can be found in a production line is the machine tool for manufacturing workpieces. Advances in manufacturing technologies allow to increase quality and efficiency in production lines, but also ask for new and increasing requirements on the motion planning and control systems. The increase of CPU processing power has permitted, in traditional CNC systems, the introduction of NURBS interpolation capabilities, thus determining a further increase in machining quality and efficiency. This has posed new and still unsolved issues, such as the need to satisfy multiple opposite constraints like limiting chord error, acceleration and jerk and offering real-time guarantees. In addition, the ability of privileging the production throughput by relaxing one or more of the previous constraints in a simple way has emerged as another requirement of modern manufacturing plants. Nevertheless, none of the existing NURBS interpolators have these characteristics. In this thesis, we propose a NURBS interpolator that is able to satisfy all the manufacturing technology requirements and is able to respect, thanks to its bounded computational complexity, the position control real-time constraints. Such interpolator is easily reconfigurable, i.e. it can relax some of the constraints and can be adapted in order to include constraints that were not originally considered. Performances of the proposed algorithm have been evaluated both by simulations and by real milling experiments. However, improvements in productivity of a the machine tool can be neutralized if the various workstations of the production line are not properly synchronized. Distributed control allows to improve the coordination of different workstations but its design is challenging. The IEC 61499 standard has been developed to ease the modeling and design of distributed control systems, providing advanced concepts of software engineering (such as abstraction, encapsulation, reuse) to the world of control engineering. The introduction of such standard in already existing control environments poses challenges, since the widespread IEC 61131-3 programming standard is not compatible with the new standard. In order to solve this problem, this thesis presents an architecture that permits to integrate modules of the two standards, allowing to exploit the benefits of both. The proposed architecture is based on coexistence of control logic of both standards. Each standard interacts with some particular interfaces that encapsulate information and functionalities to be exchanged with the other standard. A methodology of integration of 61131-3 modules in a 61499 distributed solution based on such architecture is also developed, and it is described via a case study to prove feasibility and benefits

Echtzeitfähige Softwareagenten zur Realisierung cyber-physischer Produktionssysteme

Aktuelle ökonomische Trends, wie die zunehmende Globalisierung und die wachsende Technisierung und Individualisierung vieler Konsumgüter, führen im Hinblick auf die zur Fertigung dieser Güter eingesetzte Automatisierungstechnik zu steigender Komplexität und hohen Flexibilitätsanforderungen. Ein Konzept zur Adressierung dieser Anforderungen ist die Auslegung von automatisierten Anlagen als modulares System flexibel kombinierbarer cyber-physischer Komponenten. Die namensgebende Einheit von mechatronischem Bauteil und lokaler Rechenkapazität ermöglicht Herstellern solcher Komponenten, Softwarebausteine für typische Steuer-, Bedien- oder Diagnoseaufgaben gebrauchsfertig vorzubereiten und so den (Re-)Engineeringaufwand bei der (Um-)Gestaltung des Gesamtsystems deutlich zu reduzieren. Allerdings stellt diese Vision hohe Ansprüche an die zugrundeliegende Softwarearchitektur, die von den derzeit zur Realisierung automatisierter Systeme eingesetzten Technologien nicht vollständig erfüllt werden. Das Paradigma der Agentenorientierung ist ein tragfähiger Ansatz zur Realisierung solcher lose gekoppelten verteilten Systeme und stellt durch leistungsfähige Interaktionsmechanismen sowie die enge Integration von semantischem Wissen zusätzliche Funktionalität in Aussicht: Als Agenten ausgelegte Komponenten könnten auch die logische Vernetzung untereinander während der Inbetriebnahme, nach Umrüstungen oder in Reaktion auf Betriebsstörungen teilweise selbst übernehmen. Dadurch ergeben sich Fähigkeiten wie Selbstkonfiguration und Selbstregeneration, die in der Fachliteratur unter dem Begriff Self-X zusammengefasst werden. Die fehlende Echtzeitfähigkeit, insbesondere in Bezug auf besagte Interaktionsmechanismen, hat jedoch bisher die Einsetzbarkeit von Agentensystemen in der Automatisierung limitiert und die Ausschöpfung der genannten Potentiale behindert. Deshalb wird in dieser Dissertation eine echtzeitfähige Laufzeitumgebung für Softwareagenten entworfen und anschließend die Überarbeitung bestehenden Kommunikationsmechanismen im Hinblick auf ihre Echtzeitfähigkeit vorgenommen. In diesem Kontext wird mit dem Konzept der semantischen Adressierung eine vielfältig einsetzbare Möglichkeit geschaffen, Nachrichten an ausgewählte Gruppen von Agenten mit bestimmten, semantisch beschriebenen Eigenschaften zur verschicken. Die dabei zur Wissensrepräsentation genutzten Taxonomie-Bäume bieten ein für viele Aufgabenstellungen ausreichendes Maß an Ausdrucksstärke und erlauben zudem die Verarbeitung unter harten Echtzeitbedingungen. Abschließend werden die geschaffenen Mechanismen in einem Antwortzeitmodell abgebildet, mit dem das rechtzeitige Reagieren eines Agentensystems auf lokal oder verteilt zu behandelnde Ereignisse überprüft und nachgewiesen werden kann. Damit wird ein Hauptkritikpunkt von Agentensystemen adressiert, was zu einer nachhaltigen Steigerung der Akzeptanz des Agentenparadigmas führen könnte. Während große Teile der erarbeiten Lösung als allgemeingültige Grundlagenforschung verstanden werden können, wird bei der Formulierung von Anforderungen, der Darstellung von Beispielen und der Erläuterung von Entwurfsentscheidungen immer wieder auf automatisierungstechnische Belange Bezug genommen. Außerdem wird am Ende der Arbeit eine kritische Bewertung der Ergebnisse vor dem Hintergrund eines möglichen Einsatzes in zukünftigen Automatisierungssystemen durchgeführt und damit das Gesamtbild abgerundet