Marga Marcos

A Tool Integration Framework for Industrial Distributed Control Systems

This paper presents a tool integration approach for supporting the development cycle of industrial distributed control applications. The core of the approach is a formal model of the application that expresses separately the functionality of the control system from the implementation issues. The modeling language selected is XML (eXtensible Markup Language) and the framework proposed makes use of XML technologies for achieving the integration of the tools involved within the development cycle. Following this approach, a set of tools from different domain of expertise (control engineering, software engineering, configuration, maintenance...) have been integrated into a framework. The toolset has been used for designing and validating the distributed control system of a heat treatment line.

Model-driven design of Industrial Control Systems

Industrial control systems are used in most of the industrial sectors to achieve production improvement, process optimization and time and cost reduction. Integration, reuse, flexibility and optimization are demanded to adapt to a rapidly changing and competitive market. There is also a growing requirement that all software tools that support the different phases of the development process (design, configuration, management) can be integrated as well. Thus, a consolidation of modeling methodologies for achieving this goal is needed. This paper proposes a Model-driven approach based on different views of the application (control engineering, electric engineering and software engineering views) for designing industrial control systems. The approach is based on the definition of a description language that includes the description of the three domain views and their relationships. In particular, XML schema technology is used to define the architectural style and schematron technology to implement the composition rules.

A Methodology for Multidisciplinary Modeling of Industrial Control Systems using UML

Industrial process measurement and control systems (IPMCS) are used in most of the industrial sectors to achieve production improvement, process optimization and time and cost reduction. Integration, reuse, flexibility and optimization are demanded to adapt to a rapidly changing and competitive market. Thus, a consolidation of modeling methodologies for achieving this goal is needed. In this paper, a multidisciplinary modelling of distributed IPMCS, as well as a modelling methodology are proposed. The model of the application consists of three related views that separate the functional aspects from the implementation issues (hardware and software). The complete model is constituted by the three different views as well as the relationship among them. The modelling methodology makes use of the unified modelling language (UML) and it guides a non-expert UML user through the steps needed to model the control application. To achieve this, a set of UML profiles, that characterize the different elements of each domain view, have been defined. A limited subset of UML diagrams are used to define the three domains as well as its relationships. To illustrate its use, the methodology is applied to an industrial application: the distributed control system of a heat treatment line.

Building complex remote learning laboratories

The interaction with real plants is a key issue in control engineering education in order to consolidate the concepts learned in the classroom. Unfortunately, for several reasons, real laboratories are not always available. On the other hand, Internet technologies have proved to be mature and reliable, becoming a common alternative in the creation of remote laboratories. However, the use of these technologies in complex remote laboratories is not a trivial task as several requisites must be satisfied simultaneously. This article proposes a methodology that eases the creation of remote laboratories establishing the steps to build up a remote access system. This methodology proposes a set of key components that can be used to define the access to a remote plant from a functional point of view. Some of these components are generic being reusable in most applications whereas others are application specific. In summary, the methodology allows designers to concentrate more on the functionality of the applications than on the technical aspects of the underlying technology. The use of this methodology is illustrated with a relatively complex example: A laboratory manufacturing cell.

A procedure to evaluate Extended Computed Torque Control configurations in the Stewart–Gough platform

Abstract Parallel robots have become the best solution when high speed and/or accuracy are needed in industrial robotic operations. However, in order to meet the requirements of these tasks, advanced model based controllers such as the Extended CTC scheme are required. This CTC-based scheme requires the introduction of extra sensors in the passive joints of the parallel robot. This redundant information allows to increase the robustness and performance of the control law, leading to better trajectory tracking. However, in order to achieve the best performance, a proper extra sensor distribution is required. In this paper, a sensitivity analysis based approach is applied to the well known Gough Platform in order to evaluate different extra sensor distributions. The obtained results are compared with those obtained by a statistically significant set of simulations, demonstrating the effectiveness of the methodology.

Distributed applications management platform based on Service Component Architecture

The increasing complexity in current distributed embedded systems (DES) makes its design a hard task that involves several aspects like distribution middleware selection, QoS support, implementation language selection, application dynamic reconfiguration or application deployment and maintenance. These design considerations must provide a solution to non functional requirements that distributed applications nowadays demand (e.g. Hardware heterogeneity, real time requirements, energy constraints, security, safety or fault tolerance). This paper proposes a management platform for distributed component based applications that follow the SCA (Service Component Architecture) standard. This platform provides several functionalities that range from application deployment and life cycle control to QoS and fault tolerance support.

Permutational Genetic Algorithm for the Optimized Assignment of Priorities to Tasks and Messages in Distributed Real-Time Systems

The assignment of fixed priorities to tasks and messages in distributed real-time systems is known to be an NP-hard problem, and thus there is no optimal method to accomplish it in polynomial time. This fact makes it a suitable problem to be approached with generic search and optimization algorithms. In this paper we propose a genetic algorithm with a per mutational solution encoding for the assignment of fixed priorities to tasks and messages in distributed real-time systems using a holistic approach. This paper shows that the genetic algorithm can find more and better schedulable priority assignments than HOPA, which is, as far as we know, one of the best methods for the fixed priority assignment in distributed real-time systems.

PLCopen for achieving interoperability between development phases

As fast as industry reaches a greater maturity level and applications become more complex, a consolidation of the modeling methodologies becomes necessary. They are composed by a lot of heterogeneous systems that need working together to perform automation and control tasks. AutomationML frameworks goal is to interconnect the heterogeneous tools used in the different engineering disciplines. In concrete it manages three well accepted standards: CAEX for topology, COLLADA for kinematics and geometry, and PLCopen for logic data. This paper is focused in the logic data. A logic CPF framework is defined in order to integrate tools into AutomationML framework that fulfill the logic data present in different development phases of the applications.

Design of a Virtual-Instrumentation System for a Machining Process

This paper presents a virtual-instrumentation system (VIS) that aims at measuring the evolution of key magnitudes in a nonconventional machining process called wire electrical discharge machining (WEDM). The VIS consists of two well-different parts: the acquisition system that measures process signals (voltage and current) and the virtual measurement of relevant magnitudes (such as energy, peak-current distribution, and ignition delay time). The data-acquisition system provides flexibility and ease of storing tests under different machining conditions without extra hardware construction or adaptation. It is based on a commercial data-acquisition board that works at very high frequencies (up to 10 MSamples/s). The virtual measurement is carried out by modeling and processing the acquired signals. The VIS has been employed to monitor and detect low-quality cutting regimes in WEDM.

A CPPS Architecture approach for Industry 4.0

New demands, coming from the industry 4.0 concept of the near future production systems have to be fulfilled in the coming years. Seamless integration of current technologies with new ones is mandatory. The concept of Cyber-Physical Production Systems (CPPS) is the core of the new control and automation distributed systems. However, it is necessary to provide the global production system with integrated architectures that make it possible. This work analyses the requirements and proposes a model-based architecture and technologies to make the concept a reality.