Modularity and Architecture of PLC-based Software for Automated Production Systems: An analysis in industrial companies

Adaptive and flexible production systems require modular and reusable software especially considering their long term life cycle of up to 50 years. SWMAT4aPS, an approach to measure Software Maturity for automated Production Systems is introduced. The approach identifies weaknesses and strengths of various companie's solutions for modularity of software in the design of automated Production Systems (aPS). At first, a self assessed questionnaire is used to evaluate a large number of companies concerning their software maturity. Secondly, we analyze PLC code, architectural levels, workflows and abilities to configure code automatically out of engineering information in four selected companies. In this paper, the questionnaire results from 16 German world leading companies in machine and plant manufacturing and four case studies validating the results from the detailed analyses are introduced to prove the applicability of the approach and give a survey of the state of the art in industry

Engineering framework for service-oriented automation systems

Tese de doutoramento. Engenharia Informática. Universidade do Porto. Faculdade de Engenharia. 201

Equipamento standard para montagem de componentes

Mestrado em Engenharia de Automação IndustrialO projeto apresentado surge da parceria entre a empresa Siroco e a Universidade de Aveiro, e descreve o estudo e a implementação de uma metodologia para programação de autómatos (PLC) e consolas de operação (HMI). Este documento descreve a proposta de uma metodologia baseada nos princípios da programação orientada por objetos que permite o desenvolvimento de blocos funcionais a usar na programação de alguns componentes típicos de um equipamento de montagem automatizado. Procura-se com esta abordagem diminuir o tempo de desenvolvimento de projeto dos sistemas tratados, e simplificar a implementação, integração, teste e manutenção das aplicações de software. Os blocos funcionais foram desenvolvidos na ferramenta de programação de PLC e HMI da Omron (Sysmac Studio), com recurso à utilização de estruturas denominadas de Function e Function Block. A metodologia criada foi aplicada no desenvolvimento dos blocos funcionais propostos pela empresa Siroco, para os quais a empresa propôs que se elaborassem algoritmos de controlo para as estruturas mais importantes dos equipamentos desenvolvidos pela empresa, nomeadamente os cilindros pneumáticos, pratos rotativos e estações de trabalho. É descrito o método utilizado para o desenvolvimento dos algoritmos, e é demonstrado como estes blocos podem ser aplicados no programa de controlo de um equipamento. Para finalizar, são implementados dois casos de estudo que servem para demonstrar e validar a viabilidade da metodologia proposta neste projeto.This project results from the partnership between the Siroco company and the University of Aveiro, and demonstrates the study and implementation of a methodology for the development of Programmable Logic Controller (PLC) and operator panels (HMI) programs. This document describes the proposed approach, based on principles of object-oriented programming that allows the development of functional blocks in the programming of some typical components of an automated assembly equipment. The propose of this approach is to reduce project development time of the treated systems and simplify the implementation, integration, testing and maintenance of software applications. The functional blocks were developed in the Omron PLC and HMI programming tool (Sysmac Studio), with the use of structures called of Function and Function Blocks. The methodology created was applied in the development of functional blocks proposed by Siroco company, which are to design control algorithms for the most important structures of the typical equipment developed by the company, including pneumatic cylinders, indexing tables and workstations. The method used to develop the algorithm is described, and it is shown how these blocks can be implemented in the control software of an equipment. Finally, two case studies were implemented, which served to demonstrate and validate the feasibility of the methodology proposed in this project

Generator-Composition for Aspect-Oriented Domain-Specific Languages

Software systems are complex, as they must cover a diverse set of requirements describing functionality and the environment. Software engineering addresses this complexity with Model-Driven Engineering ( MDE ). MDE utilizes different models and metamodels to specify views and aspects of a software system. Subsequently, these models must be transformed into code and other artifacts, which is performed by generators. Information systems and embedded systems are often used over decades. Over time, they must be modified and extended to fulfill new and changed requirements. These alterations can be triggered by the modeling domain and by technology changes in both the platform and programming languages. In MDE these alterations result in changes of syntax and semantics of metamodels, and subsequently of generator implementations. In MDE, generators can become complex software applications. Their complexity depends on the semantics of source and target metamodels, and the number of involved metamodels. Changes to metamodels and their semantics require generator modifications and can cause architecture and code degradation. This can result in errors in the generator, which have a negative effect on development costs and time. Furthermore, these errors can reduce quality and increase costs in projects utilizing the generator. Therefore, we propose the generator construction and evolution approach GECO, which supports decoupling of generator components and their modularization. GECO comprises three contributions: (a) a method for metamodel partitioning into views, aspects, and base models together with partitioning along semantic boundaries, (b) a generator composition approach utilizing megamodel patterns for generator fragments, which are generators depending on only one source and one target metamodel, (c) an approach to modularize fragments along metamodel semantics and fragment functionality. All three contributions together support modularization and evolvability of generators

How might the development of data mining and log analysis systems for the Moodle virtual learning environment improve computer science students’ course engagement and encourage course designers’ future engagement with data analysis methods for the evaluation of course resources?

Virtual learning environments (VLEs) form part of modern pedagogy in education, they contain student usage data that has potential to inform and improve this pedagogy. The question this thesis explores is how might the development of data mining and log analysis systems for the Moodle virtual learning environment, improve computer science students’ course engagement and encourage course designers’ future engagement with data analysis methods for the evaluation of course resources? The thesis proposes that a student will complete missed work sooner if their utilisation of the VLE is automatically tracked and electronic prompts are sent when VLE activities are missed. The thesis also hypothesises that presenting a simple-to-use data mining and visualisation tool to course designers would increase their future acceptance of data mining technology for informing course design with a longer-term intent that this would improve the quality of the online learning experience ultimately improving student engagement. Exploring the two hypotheses required the development of two software artefacts, MooTwit – a tool that contacts students when they fall behind in their VLE study and MooLog – a tool that extracts and presents summative information on VLE course utilisation. To establish if student timely engagement improved, the study used MootTwit with two groups of students over a period of 15 weeks, messaging one group only when they fell behind. Statistical analysis and comparisons were made between how quickly each group engaged with the missed items. Using MooTwit to track and contact students did influence the timeliness of their engagement with the VLE activities. Specifically, the results suggest by direct messaging a student to engage with missed material, they complete missed activities closer to required completion date. To ascertain if the acceptance of data mining for course evaluation could be improved, surveys were used before and after a demonstration of MooLog to a group of course designers. The pre-demonstration survey assessed existing planning and evaluation processes. The post-demonstration survey collected evaluations of the relevance of the information provided by MooLog and the likelihood of Page 3 of 120 the software being used to evaluate course effectiveness. The results of the study established that many designers currently do not use data analysis as a method of informing course improvement and there was evidence to suggest the MooLog demonstration significantly increased acceptance of the potential of data mining. The findings within the thesis show that educational data-mining has the potential to improve pedagogy in VLE linked education offering opportunities to increase timely engagement and to raise course designers’ acceptance of data mining to improve the validity and quality of course evaluation

Interdisziplinäre Variabilitätsmodellierung und Performance Analyse für langlebige Systeme in der Automatisierungstechnik

In this day and age, automation systems have to deal with differing customer needs, environmental requirements and multiple application contexts. Automation systems have to be variable enough to satisfy all of these demands. The development and maintenance of such highly-customizable systems is a challenging task and becomes increasingly more difficult considering multiple involved engineering disciplines and long lifetimes, which is characteristic for industrial systems of the automation domain. Software product line engineering provides developers with fundamental concepts to manage the variability of such systems. However, these concepts are not established in the domain of automation systems. In addition, the involvement of multiple engineering disciplines poses a threat to existing SPL techniques. This thesis contributes novel approaches to improve the development and maintenance of software-intensive automation product lines. In total, three major contributions are made, spanning across the complete design phase of an automation system. (1) The feature modeling process is improved by detecting hidden dependencies between interrelated feature models from separate engineering disciplines. Furthermore, hidden dependencies and occurring defects in the feature models are explained in a user-friendly manner. (2) A model-driven development approach is introduced consisting of UML models, which are extended with delta modeling to manage variability in the automation product line. The models encompass information that is needed to automatically derive and analyze a performance model. (3) Subsequently, an efficient family-product-based performance analysis is proposed for the previously derived UML models that is vastly superior compared to common product-based approaches. All of these techniques have been evaluated using multiple case studies, with one being a real-world automation system.In der heutigen Zeit sehen sich Automatisierungssysteme mit einer steigenden Komplexität konfrontiert. Einzelne Kunden haben unterschiedliche Ansprüche an das System und ebenso müssen Umweltbedingungen der verschiedenen Betriebsumgebungen sowie abweichende Anwendungsgebiete bei der Entwicklung eines Automatisierungssystems berücksichtigt werden. Diese Komplexitätsaspekte werden unter dem Stichwort Variabilität zusammengefasst. Ein Automatisierungssystem muss in der Lage sein, sämtliche Anforderungen zu erfüllen. Die Entwicklung und Wartung dieser Systeme wird jedoch durch die stetig wachsende Variabilität und eine potentiell lange Lebensdauer immer schwieriger. Zusätzlich sind an dem Entwicklungsprozess eines Automatisierungssystems mehrere Ingenieursdisziplinen beteiligt. Die Techniken aus dem Bereich der Software-Produktlinienentwicklung bilden Lösungen, um die Variabilität beherrschbar zu machen. In der Automatisierungstechnik sind diese Techniken weitgehend unbekannt und durch den interdisziplinären Charakter oft nicht ausreichend. Daher werden in dieser Dissertation neue Ansätze entwickelt und vorgestellt, die auf die Domäne der Automatisierungstechnik zugeschnitten sind. Insgesamt leistet diese Dissertation folgende drei wissenschaftlichen Beiträge: (1) Die Entwicklung von Feature-Modellen wird durch die Detektion von verborgenen Abhängigkeiten, die zwischen Feature-Modellen der unterschiedlichen Ingenieursdisziplinen existieren, verbessert. Gleichzeitig liefert der vorgestellte Algorithmus die Erklärung für die Existenz dieser Abhängigkeiten. Dieses Konzept wird auf weitere Defekte in Feature-Modellen ausgeweitet. (2) Einen modell-basierten Ansatz zur Entwicklung eines Automatisierungssystems. Der Ansatz basiert auf Modellen aus der UML, die mit Hilfe der Delta Modellierung Variabilität abbilden können. Zusätzlich sind die Modelle mit Informationen über Performance Eigenschaften angereichert und erlauben die automatische Ableitung eines Performance-Modells. (3) Eine effiziente Performance Analyse von allen Varianten des Automatisierungssystems, die auf den zuvor abgeleiteten Performance-Modellen basiert. Alle Beiträge wurden mit Fallstudien evaluiert. Eine Fallstudie repräsentiert ein reales Automatisierungssystem