Логічний синтез дискретних систем автоматичного керування при використанні програмованих реле низького рівня

Логічний синтез дискретних систем автоматичного керування при використанні програмованих реле низького рівня = Logical synthesis of discrete automatic control systems using low-level programmed relays / С. О. Бур’ян, М. В. Печеник, Г. Ю. Землянухіна, І. С. Єпіфанцев // Зб. наук. пр. НУК. – Миколаїв : НУК, 2021. – № 1 (484). – С. 54–60.Анотація. Для керування комплексними системами автоматизації, як правило, використовуються інтелектуальні промислові контролери, які мають досить складну структуру і високі вартісні характеристики. Разом із тим для локальних систем керування, які забезпечують виконання певної виробничої задачі або самостійно, або в рамках загального технологічного циклу, досить перспективним є використання програмних реле низького рівня, яким властиві невисока вартість, простота в програмуванні, зручність в експлуатації. Однак недоліком зазначених реле можна відзначити обмежену кількість комірок пам’яті й елементів, які записуються в програмі, що у свою чергу призводить до використання більш дорогих контролерів для локальних систем автоматизації з великою кількістю станів. Мета. Вдосконалення методу синтезу логічних схем на основі графопереходів для використання його під час розроблення дискретних систем керування технологічними процесами з великою кількістю станів за умови технічної реалізації програми на логічних реле низького класу. Методика. Вдосконалення методу синтезу полягає в перетворенні громіздкого графопереходу, який описує переходи між станами дискретної схеми в ланцюг із декількох графопереходів, кожен з яких описує частину станів системи автоматизації або технологічного процесу. Останній сигнал, який переводить поточний графоперехід у вихідний стан, є одночасно першим сигналом наступного графопереходу. Це у свою чергу знімає обмеження застосування в складних системах автоматизації логічних реле низького рівня, оскільки зменшується кількість комірок пам’яті, необхідних для написання програми. Результати. Запропонована модифікація передбачає, що замість одного графопереходу, що описує всі стани системи автоматизації, застосовується ланцюг із невеликих графопереходів, які послідовно переходять з одного на інший. При цьому зменшується кількість кон’юнктивних членів у кожному рівнянні, що дозволяє використовувати отримані рівняння для складання програм для логічних програмованих реле, що мають обмеження за кількістю комірок пам’яті та кількістю елементів, що записуються в програмі. Наукова новизна. Вдосконалено метод синтезу дискретних систем автоматизації на основі графопереходів, який полягає в перетворенні громіздкого графопереходу, що описує переходи між станами дискретної схеми, в ланцюг із декількох графопереходів, кожен з яких описує частину станів системи автоматизації або технологічного процесу. Практична значимість. Вдосконалений метод має елементи уніфікації, і його можна використовувати для синтезу логічних рівнянь, що описують системи автоматичного керування, які працюють за лінійним алгоритмом, тобто схема послідовно переходить з одного стану в інший, що є характерною рисою також і для електромеханічних систем механізмів загальнопромислового призначення циклічного режиму роботи.Abstract. To control complex automation systems, as a rule, intelligent industrial controllers are used, which have a rather complex structure and high cost characteristics. However, for local control systems that provide a certain production task either independently or within the general technological cycle is quite promising to use low-level software relays, which are characterized by low cost, ease of programming, ease of operation. However, the disadvantage of these relays is the limited number of memory cells and elements that are recorded in the program, which in turn leads to the use of more expensive controllers for local automation systems with a large number of states. Purpose. Improving the method of synthesis of logic circuits based on graph transitions for its use in the development of discrete process control systems with a large number of states under the condition of technical implementation of the program on low-class logic relays. Method. The improvement of the synthesis method is to transform a bulky graph transition, which describes the transitions between the states of a discrete circuit into a chain of several graph transitions, each of which describes part of the states of the automation system or process. The last signal that converts the current graph transition to the initial state is also the first signal of the next graph transition. This in turn removes the limitations of using low-level logic relays in complex automation systems, as it reduces the number of memory cells required to write a program. Results. The proposed modification assumes that instead of one graph transition, which describes all the states of the automation system, a chain of small graph transitions is used, which successively pass from one to another. This reduces the number of conjunctive terms in each equation, which allows you to use the resulting equations to compile programs for logic programmable relays, which are limited by the number of memory cells and the number of elements recorded in the program. Scientific novelty. The method of synthesis of discrete automation systems based on graph transitions is improved, which consists in transforming a bulky graph transition describing transitions between states of a discrete circuit into a chain of several graph transitions, each of which describes a part of automation system or process states. Practical importance. The advanced method has elements of unification and can be used to synthesize logical equations describing automatic control systems that operate on a linear algorithm, i.e. the circuit sequentially passes from one state to another, which is also a characteristic feature of electromechanical systems of general industrial mechanisms of cyclic mode work

Decentralized proportional-integral controller based on dynamic decoupling technique using Beckhoff TwinCAT-3.1

An improved technique for the design of decentralized dynamic decoupled proportional-integral (PI) controllers to control many variables of column flotation was developed and implemented in this paper. This work was motivated by challenges when working with multiple inputs and multiple outputs (MIMO) systems that are not controllable by conventional linear feedback controllers. Conventional feedback control design consists of various drawbacks when it comes to complex industrial processes. The introduction of decentralization, decoupling, and many advanced controls design methods overcomes these drawbacks. Hence, the design and implementation of control systems that mitigate stability for MIMO systems are important. The developed closed-loop model of the flotation process is implemented in a real-time platform using TwinCAT 3.1 automation software and CX5020 Beckhoff programmable logic controllers (PLC) through the model transformation technique. The reasons for using the CX5020 as an implementation environment were motivated by the reliability, and is built according to new industry standards, allowing transformation, which makes it more advantageous to be used more than any other PLCs. This is done to validate the effectiveness of the recommended technique and prove its usability for any multivariable system. Comparable numerical results are presented, and they imply that industrial usage of this method is highly recommended

Engineering methods and tools for cyber–physical automation systems

Much has been published about potential benefits of the adoption of cyber–physical systems (CPSs) in manufacturing industry. However, less has been said about how such automation systems might be effectively configured and supported through their lifecycles and how application modeling, visualization, and reuse of such systems might be best achieved. It is vitally important to be able to incorporate support for engineering best practice while at the same time exploiting the potential that CPS has to offer in an automation systems setting. This paper considers the industrial context for the engineering of CPS. It reviews engineering approaches that have been proposed or adopted to date including Industry 4.0 and provides examples of engineering methods and tools that are currently available. The paper then focuses on the CPS engineering toolset being developed by the Automation Systems Group (ASG) in the Warwick Manufacturing Group (WMG), University of Warwick, Coventry, U.K. and explains via an industrial case study how such a component-based engineering toolset can support an integrated approach to the virtual and physical engineering of automation systems through their lifecycle via a method that enables multiple vendors' equipment to be effectively integrated and provides support for the specification, validation, and use of such systems across the supply chain, e.g., between end users and system integrators

Developing Function Blocks for Collecting Data and Integrating Legacy Systems in Manufacturing and Logistics

Manufacturing enterprises have been increasingly technology-driven during recent decades. Industry 4.0 promotes smart manufacturing and intelligent systems which can seamlessly communicate with each other and enable decentralized decision-making by monitoring the factory-floor process. This calls for the Information Communication Technologies (ICT) infrastructure to be effectively incorporated with the industries. Industry 4.0 presents the concept of “smart factory” in which Cyber-Physical-Systems (CPS) fuses the physical systems with the Internet of Things (IoT), enabling higher levels of interoperability and Information transparency. However, manufacturing enterprises in the recent past have characterized their efficiency by how prominently and adequately they adopt and utilize their IT solutions and how feasible those solutions are to integrate with their legacy systems. Enterprise Integration, in particular, has become more challenging owing to the highly dynamic manufacturing environment. System integration has become an indispensable field to be addressed , especially when the industry adopts connected enterprise paradigm. Connected enterprise systems enable industries to leverage their technologies to collect, analyze and refine their data to help them make better business decisions. In a recent trend, IT systems in manufacturing are majorly driven towards the cloud and collaborative solutions as a result of the exponential growth of internet technologies and their ability to adapt to rapid changes in the market. Collaborative frameworks are widely preferred by the enterprises as they enable better communication, increases productivity and improve business execution. They are critical for a business to function with agility in this fast pacing and changing world. One such platform is provided by the Cloud Collaborative Manufacturing Networks (C2NET) project that optimizes the supply network of manufacturing and logistics assets. This thesis research proposes an approach to integrate heterogeneous legacy systems by showcasing an implementation which favors robust data collection. This implementation is made possible by adopting Production Logistics and Sustainability Cockpit (PLANTCockpit) Open Source solution, which functions as a viable interface for real-time data collection and data-logistics thus enhancing the process optimization of the manufacturing enterprise. PLANTCockpit OS is a modular solution which enables to build and deploy flexible loosely coupled entities known as Function Blocks (FBs) that facilitate seamless legacy system integration and robust information exchange between the systems. This thesis also fulfills the C2NET project requirement to define the possibility of effective integration of PLANTCockpit OS in the C2NET reference architecture

Multi-Agent Modelling of Industrial Cyber-Physical Systems for IEC 61499 Based Distributed Intelligent Automation

Traditional industrial automation systems developed under IEC 61131-3 in centralized architectures are statically programmed with determined procedures to perform predefined tasks in structured environments. Major challenges are that these systems designed under traditional engineering techniques and running on legacy automation platforms are unable to automatically discover alternative solutions, flexibly coordinate reconfigurable modules, and actively deploy corresponding functions, to quickly respond to frequent changes and intelligently adapt to evolving requirements in dynamic environments. The core objective of this research is to explore the design of multi-layer automation architectures to enable real-time adaptation at the device level and run-time intelligence throughout the whole system under a well-integrated modelling framework. Central to this goal is the research on the integration of multi-agent modelling and IEC 61499 function block modelling to form a new automation infrastructure for industrial cyber-physical systems. Multi-agent modelling uses autonomous and cooperative agents to achieve run-time intelligence in system design and module reconfiguration. IEC 61499 function block modelling applies object-oriented and event-driven function blocks to realize real-time adaption of automation logic and control algorithms. In this thesis, the design focuses on a two-layer self-manageable architecture modelling: a) the high-level cyber module designed as multi-agent computing model consisting of Monitoring Agent, Analysis Agent, Self-Learning Agent, Planning Agent, Execution Agent, and Knowledge Agent; and b) the low-level physical module designed as agent-embedded IEC 61499 function block model with Self-Manageable Service Execution Agent, Self-Configuration Agent, Self-Healing Agent, Self-Optimization Agent, and Self-Protection Agent. The design results in a new computing module for high-level multi-agent based automation architectures and a new design pattern for low-level function block modelled control solutions. The architecture modelling framework is demonstrated through various tests on the multi-agent simulation model developed in the agent modelling environment NetLogo and the experimental testbed designed on the Jetson Nano and Raspberry Pi platforms. The performance evaluation of regular execution time and adaptation time in two typical conditions for systems designed under three different architectures are also analyzed. The results demonstrate the ability of the proposed architecture to respond to major challenges in Industry 4.0

The programmable logic controller : its prehistory, emergence and application

Programmable Logic Controllers (PLCs) are widely used devices controlling industrial machines and processes and many other diverse applications, requiring primarily, combinatorial logic and sequential control. The PLC is a hidden technology, little known by the general public and overlooked in academic historical studies of technology. The research reported in this thesis aims to address this lack of awareness. The thesis explores the development of sequential and combinatorial logic control technologies, the emergence of the PLC, its subsequent development and its industrial applications. Patents and first- hand accounts and experiences from senior industrial engineers in a number of diverse manufacturing industries have been used as the primary research sources since, as a hidden technology, academic historical accounts are sparse. This approach illustrates, through using the PLC as an example, a potential method of studying other, unrelated hidden technologies. The research has revealed the influence of geography, industrial settings and earlier engineering practices on the design, selection and application of PLC control technologies, and comments on the how these influences define specific communities of practice

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