Design of a mechatronic system for application of hardware-in-the-loop simulation technique

Classical approaches, using Simulation analysis technique, use a controller model that can – or not – be coupled with a plant model. Usually, the controller and plant models are connected, in a closed-loop behavior, and this kind of Simulation is called Software-in-the-loop Simulation (SIL). However, recently, some directions are being assumed and some recent works deal with Simulation considering the real controller, instead of the controller model, in the closed loop behavior with the plant model and this kind of approach is called Hardwarein- the-loop simulation (HIL). In order to study and to propose some rules about the simulation of real-time systems considering HIL simulation, at the Automation Laboratory of the Centre for Mechanics and Materials Technologies of the University of Minho, Portugal – a workbench especially devoted to this study is being developed. This workbench considers an environment for Simulation, and the respective programming language, and a real controller that interacts with the simulation environment running on a PC. After looking at the available software tools and modeling languages, Dymola simulation environment and Modelica modeling language were chosen. The main reasons for this choice are associated with the unique multi-domain engineering capabilities of Dymola and Modelica that allow to deal, on the same environment, with many different engineering domains like hydraulics, power train, thermodynamics, air-conditioning, vehicle dynamics, mechanical, electrical, electronic, control, thermal, pneumatic, among others... As real controller, the choice was a Programmable Logic Controller (PLC) from OMRON company, the CPM2A model. This paper presents the first step, of this ongoing work, and is focused, mainly, on studying how to exchange information between a real PLC (used, as controller, on the designed workbench) and Dymola software that will run specific plant models, developed in Modelica language, on a Personal Computer.(undefined

Industrially Applicable System Regression Test Prioritization in Production Automation

When changes are performed on an automated production system (aPS), new faults can be accidentally introduced in the system, which are called regressions. A common method for finding these faults is regression testing. In most cases, this regression testing process is performed under high time pressure and on-site in a very uncomfortable environment. Until now, there is no automated support for finding and prioritizing system test cases regarding the fully integrated aPS that are suitable for finding regressions. Thus, the testing technician has to rely on personal intuition and experience, possibly choosing an inappropriate order of test cases, finding regressions at a very late stage of the test run. Using a suitable prioritization, this iterative process of finding and fixing regressions can be streamlined and a lot of time can be saved by executing test cases likely to identify new regressions earlier. Thus, an approach is presented in this paper that uses previously acquired runtime data from past test executions and performs a change identification and impact analysis to prioritize test cases that have a high probability to unveil regressions caused by side effects of a system change. The approach was developed in cooperation with reputable industrial partners active in the field of aPS engineering, ensuring a development in line with industrial requirements. An industrial case study and an expert evaluation were performed, showing promising results.Comment: 13 pages, https://ieeexplore.ieee.org/abstract/document/8320514

Design of a Control System for a Reconfigurable Engine Assembly Line

Today’s automotive manufacturing environment is dynamic. It is characterized by short life cycles of products especially in powertrain, due in part to changing Government regulations for fuel economy. In the USA, the National Highway Traffic and Safety Administration (NHTSA), Corporate Average Fuel Economy (CAFE) mandates an average of 29 miles per gallon (mpg), gradually increasing to 35.5 mpg by 2016 and 54.5 mpg towards 2025. Life cycles of engines and transmissions have consequently shortened, driving automakers to develop and manufacture more efficient powertrains. Not long ago, plants produced engines for decades, with minor modifications warranting slight manufacturing line rework. Conversely, today’s changing trends require machines and complete engine line overhauls rendering initial setups obsolete. Automakers compete to satisfy government regulations for best mileage and also lower manufacturing cost, thus the adoption of Reconfigurable Manufacturing Systems (RMS). Production lines follow modularity in designs, for hardware and software, to adapt to new business conditions, economically and time-wise. Information Technology (IT) and Controls are growing closer with the line of demarcation disappearing in manufacturing. Controls are benefiting from opportunities in IT, hardware and software. The advent of agent-based technology which are autonomous, cooperative and extendible in different production activities, helped to develop controls for RMS in academia. Component-based software suitable for RMS modularity and plug-and-play hardware/software components has gained decades of popularity in the software industry. This thesis implements distributed controls imbedding component-based technology and IEC 61311-3 function block standard for automotive engine assembly, which will contribute to these developments. The control architecture provides reconfigurability which is lacking in current manufacturing systems. The research imbeds: 1- Reconfigurability - Fitting RMS-designed hardware towards new manufacturing, 2- Reusability - Building software library for reuse across assembly lines, and 3- Plug-and-Play - Embedding easy to assemble software components (function blocks)

Modelação da parte física de sistemas mecatrónicos e estudo da sua influência em simulação MiL (Model-in-the-loop)

Dissertação de mestrado integrado em Engenharia MecatrónicaA implementação de sistemas automatizados na indústria implica o treino de pessoal especializado para trabalhar/desenvolver sistemas constituídos por autómatos programáveis (vulgarmente denominados como PLC’s, do inglês programmable logic controller), sensores e atuadores de vários tipos e funções, desde o simples comando de uma válvula até complexos controladores de processos. A principal vantagem desta plataforma de simulação é a possibilidade de fornecer aos alunos novas estratégias e metodologias de aprendizagem, tendo como base as práticas laboratoriais direcionadas ao que irão encontrar no mercado de trabalho. Através da utilização do seu computador pessoal, os alunos serão capazes de aprender ao seu próprio ritmo, autonomamente, tendo a capacidade de descobrir e incidir na resolução das suas próprias dificuldades. Esta dissertação apresenta todo o processo de construção de plataformas de simulação virtuais de sistemas automatizados, réplicas de sistemas reais, para que o controlo do sistema possa ser simulado virtualmente utilizando a simulação Model-In-the-Loop. Devido às vantagens destes processos, esta plataforma foi desenvolvida no contexto do ensino da área de automação aos estudantes das várias áreas da Engenharia. Dado isto, ao longo desta tese são enunciados todos os passos para o desenvolvimento da plataforma, assim como os formalismos e ferramentas utilizados.The implementation of automated systems in the industry involves training specialized personnel to work / develop systems consisting of programmable logic controllers (commonly referred to as PLC's), sensors and actuators of various types and functions, from the simple command of a valve to complex processes controllers. The main advantage of this simulation platform is the ability to provide students new learning strategies and methodologies, based on laboratory practices directed at what they will find in their labor market. Through the use of their personal computer, students will be able to learn at their own pace, independently, having the ability to discover and focus on solving their own problems. This thesis presents the entire process of building platforms for virtual simulation of automated systems, replica of real systems, so that the control system can be simulated using the simulation virtually Model-In-the-Loop. Due to the advantages of these processes, this platform has been developed in the context of teaching automation to the students of the most extensive areas of Engineering. Given that, along this thesis are listed all the steps for the development of the platform, as well as formalisms and tools used

An approach to open virtual commissioning for component-based automation

Increasing market demands for highly customised products with shorter time-to-market and at lower prices are forcing manufacturing systems to be built and operated in a more efficient ways. In order to overcome some of the limitations in traditional methods of automation system engineering, this thesis focuses on the creation of a new approach to Virtual Commissioning (VC). In current VC approaches, virtual models are driven by pre-programmed PLC control software. These approaches are still time-consuming and heavily control expertise-reliant as the required programming and debugging activities are mainly performed by control engineers. Another current limitation is that virtual models validated during VC are difficult to reuse due to a lack of tool-independent data models. Therefore, in order to maximise the potential of VC, there is a need for new VC approaches and tools to address these limitations. The main contributions of this research are: (1) to develop a new approach and the related engineering tool functionality for directly deploying PLC control software based on component-based VC models and reusable components; and (2) to build tool-independent common data models for describing component-based virtual automation systems in order to enable data reusability. [Continues.

Desenvolvimento de plataformas de automação digitais

Dissertação de mestrado integrado em Engenharia MecânicaA implementação de sistemas automatizados na indústria implica o treino prévio de pessoal especializado na implementação de autómatos programáveis (vulgarmente denominados como PLCs, do inglês Programmable Logic Controller), de sensores e atuadores de vários tipos e funções, desde o simples comando de uma válvula até complexos controladores de processos. Este trabalho tem como objetivo criar uma ferramenta de simulação, onde os estudantes possam testar a implementação e comportamento de sistemas automatizados reais. Assim esta dissertação apresenta uma plataforma de simulação de sistemas automatizados, réplicas de sistemas reais, para que o comando do sistema possa ser simulado virtualmente, utilizando simulação Model-In-the-Loop. A plataforma foi desenvolvida no contexto do ensino de Sistemas a Eventos Discretos a estudantes de Engenharia Mecânica e Engenharia Eletrónica. A principal vantagem desta plataforma de simulação é o facto da metodologia de desenvolvimento poder ser estendida a outros exemplos práticos ilustrativos, disponibilizando aos estudantes novas estratégias e metodologias de ensino relacionadas com práticas laboratoriais. No desenvolvimento deste trabalho, procedeu-se à divisão da plataforma de automação em duas partes, parte de comando e parte física. Ambas sincronizadas uma vez que uma não funciona sem a outra. Neste trabalho aborda-se apenas o desenvolvimento da parte de comando sendo a parte de comando abordado noutra trabalho complementar a este. Dado isto, os passos para o desenvolvimento da parte de comando da plataforma, assim como os formalismos e ferramentas utilizadas estão descritas ao longo desta dissertação.The implementation of automated systems in the industry implies the prior training of specialized personnel in the implementation of PLCs (Programmable Logic Controller), sensors and actuators of various types and functions, from simple command to a valve controlling complex processes. This work aims to create a simulation tool, where students can test the implementation and performance of automated real. This thesis presents a simulation platform for automated systems, replicas of real systems, so that the control system can be simulated virtually simulation using Model- In-the - Loop. The platform was developed in the context of the teaching of Discrete Event Systems to students of Mechanical and Electronics Engineering. The main advantage of this simulation platform is that the development methodology can be extended to other illustrative examples, providing students with new strategies and teaching methodologies related to laboratory practice. In developing this work, we proceeded to the division of the automation platform into two parts, the command and the physical. Both synchronized since it will not operate without one another. In this paper only discusses the development of the control command being addressed in another part of this supplementary work. Given this, the steps for the development of part of the platform control, as well as formalisms and tools used are described throughout this thesis

Formal Specification and Verification of Industrial Control Logic Components

Component-based programming frameworks for industrial control logic development promise to shorten development and modification times, and to reduce programming errors. To get these benefits, it is, however, important that the components are specified and verified to work properly. This work introduces Reusable Automation Components (RACs), which contain not only the implementation details but also a formal specification defining the correct use and behaviour of the component. This formal specification uses temporal logic to describe time-related properties and has a special structure developed to meet industrial control needs. The RAC can be formally verified, to determine whether the implementation fulfils the specification or not. A RAC prototype development tool has been developed to demonstrate this capability. The main difference between the RAC and other frameworks for formal verification of control logic is the specification modeling. In RAC, not only the implementation but also the specification is based on the structure and languages of conventional control logic, aiming at being easy to comprehend for control logic engineers. Several industrial examples are discussed in this paper, showing the benefits and potential of the framework. Note to Practitioners-Today robots and machines in automated production are usually controlled by a special industrial computer called Programmable Logic Controller (PLC). Although PLC programs are widely used in manufacturing industry, current programs tend to be difficult and time-consuming to modify when needed. They are also often tested to work first on the real equipment, which may be expensive since the regular production is stopped for code testing and error resolving. In this work, we introduce Reusable Automation Components (RACs), to facilitate PLC program development. Reusing components may speed up the development and also reduce the number of errors, if the components are already verified to work properly before the reuse. To achieve this, the RACs can be richly specified, defining the correct use and behaviour of the components. The specification can then be used to verify, formally, whether the RAC works correctly or not, according to the specification. Formal verification uses math-based models and algorithms to automatically explore all possible behaviours of the component. The RAC can be automatically translated to a tool that performs the formal verification and shows counterexamples if the specification is not fulfilled. The specification and verification of RACs are intended to be useful for control logic engineers. Hence, the specification of the RAC is based on the structure and languages of conventional PLC programs. This paper discusses a number of industrial examples which show the applicability of the RACs. The RAC framework can be further improved, especially by developing guidelines and aid for writing the specifications