Franz Auinger

Usability and Interoperability of IEC 61499 based distributed automation systems

Since IEC 61499 has reached the state of an international standard and a substantial body of research results exists the question of the authors as main intention for this paper was: Do the models of IEC 61499 solve all problems when thinking of usability and interoperability in heterogeneous system environments? The main problems discussed within the paper concern to the execution model defined for basic function blocks and the scheduling of events within function block networks.

Executing real-time constrained control applications modelled in IEC 61499 with respect to dynamic reconfiguration

New fast moving markets demand flexible, adaptable production facilities to allow manufacturing companies a fast reaction on consumer needs. Reconfigurable manufacturing systems provide a solution for these problems. Currently used software architectures have not been designed for providing an infrastructure for such manufacturing systems. With the new standard IEC 61499 the International Electrotechnical Commission provides an architecture for flexible distributed control systems. But it leaves open points regarding real-time execution and reconfiguration in realtime. This work focuses on real-time execution of IEC 61499 applications. It describes all execution elements of IEC 61499 within a device. Different implementation and scheduling approaches are compared and discussed. A first real-time scheduling approach for IEC 61499 control applications allows executing applications with periodic real-time constraints in parallel to unconstrained applications. It serves as a base for an enhanced full featured IEC 61499 real-time execution support.

Platforms for Scalable Flexible Automation Considering the Concepts of IEC 61499

This work introduces approaches and embedded execution platforms for implementing the IEC 61499 (IEC, 2000) execution model. The IEC 61499 execution model is described as defined in the IEC 61499 standard. Issues that currently are not in the scope of the standard are discussed and by means of an illustrated IEC 61499 example application, it introduces different approaches that are beyond the standards’ definition for embedding IEC 61499 on execution platforms with restricted memory, performance and operating system. Moreover the execution platforms as well as their implemented execution model are described and their advantages and disadvantages are illustrated.

Towards engineering methods for reconfiguration of distributed real-time control systems based on the reference model of IEC 61499

Adaptive Manufacturing is identified by the European High-Level Group (Manufuture2004) as one of four major drivers of industrial technologies in “Manufacturing 2020”. New technologies for efficient engineering of safe, fault-tolerant and downtimeless systems and their adaptations are preconditions for this vision of future manufacturing. Without such solutions, engineering adaptations of the Industrial Automation and Control Systems (IACS) will by far exceed the costs of engineering the initial system and the reuse of equipment becomes inefficient. In this work a new approach for model driven, component based development of safe, downtimeless, distributed real–time control and for fault–tolerant, controlled evolution of IACS during their adaptation is proposed. This new method significantly increase engineering efficiency and reuse in component-based IACS.

Development, implementation and use of an IEC 61499 function block library for embedded closed loop control

A wide range of industrial processes and applications are controlled by closed loop control systems. Such processes consist of the plant that needs to be controlled and of controlling elements such as actuators, sensors, regulators or controllers. Due to decreasing hardware costs controllers are more and more integrated into sensors, actuators or other field devices. The result is increased modularity, scalability and more intelligence of the control networks that can be built out of these new mechatronic devices. To be able to program such systems in a convenient and intuitive way the function block (FB) oriented IEC 61499 standard for modeling and engineering of distributed industrial process measurement and control systems was developed. First prototypes were successfully applied to the area of distributed discrete controllers. For the area of closed loop control there seems to be a natural link between block diagram descriptions of closed loop control elements and the FB concepts of IEC 61499. But up to now efforts for mapping and implementing the wide range of block diagram element of closed loop control theory to IEC 61499 constructs were outstanding. The goal of this paper is to investigate the possibilities for applying the concept of the IEC 61499 standard to the field of closed loop control. Therefore, computer aided design and engineering tools for closed loop control systems that are currently used by control engineers for design and control of centralized automatic control systems are analyzed regarding their capabilities. Based on this information, new FB types are identified to cover the core functionality that is necessary for the implementation in closed loop control systems. Based on this analysis a library of FB types for closed loop control applications was developed and applied. The usage and limitations of IEC 61499 for distributed closed loop control is demonstrated on a real experiment - the control of a challenging seesaw problem

Overview: a simulation based metaheuristic optimization approach to optimal power dispatch related to a smart electric grid

The implementation of intelligent power grids, in form of smart grids, introduces new challenges to the optimal dispatch of power. Thus, optimization problems need to be solved that become more and more complex in terms of multiple objectives and an increasing number of control parameters. In this paper, a simulation based optimization approach is introduced that uses metaheuristic algorithms for minimizing several objective functions according to operational constraints of the electric power system. The main idea is the application of simulation for computing the fitness-values subject to the solution generated by a metaheuristic optimization algorithm. Concerning the satisfaction of constraints, the central concept is the use of a penalty function as a measure of violation of constraints, which is added to the cost function and thus minimized simultaneously. The corresponding optimization problemis specified with respect to the emerging requirements of future smart electric grids.

Automatic control application recovery in distributed IEC 61499 based automation and control systems

Modern industrial automation systems are supposed to execute applications distributed across heterogeneous networks. Additionally the market has raised a demand for downtime less operation and change of automation and control for such systems. Consequently appropriate concepts for recovering and reconfiguring devices during full operation are needed. The open standard IEC 61499 provides a scalable architecture to model applications for such distributed control systems. It supports interoperability, configurability and portability of control applications and therefore delivers the basis for online-configuration and recovery of heterogeneous systems. The main goal of this paper is to present a concept for autonomous recovery of applications within the context of distributed systems. The proposed concept facilitates the exchange of devices without any need for extra configuration. It supports an automatic recognition of new components in a distributed automation & control system and an automated up & download of control applications, user data and configuration data. The introduced approach is tested using an Ethernet-interconnected distributed demonstration system, consisting of standard personal computers with a running IEC 61499 function block development kit

Engineering of communication links with AADL in IEC 61499 automation and control systems

Todays automation systems are increasingly composed of heterogeneous distributed components. The components of such systems communicate via different protocols and need to provide a pre-specified quality of service (QoS). For modeling such distributed applications new concepts like the standard IEC 61499 are available. But IEC 61499 does not sufficiently cover the description of the communication properties between subcomponents. However the Architecture Analysis and Design Language (AADL) seems to allow sufficiently formal modelling of communication parameters and QoS parameters. This paper compares the application modelling with IEC 61499 and AADL on the basis of a simple example and shows an approach how to map IEC 61499 applications to AADL. Both contribute to derivation of communication links between reliable distributed real time components automatically out of a system independent application description, a system description and mapping parameters.

A Distributed Energy Management Approach for Autonomous Power Supply Systems

Currently applied autonomous power supplies are designed for specific energy demands and therefore rather inflexible. For an increased user friendliness, allowing attaching and detaching electrical devices without new load calculations, a flexible Power Distribution System is necessary. This can be reached by applying an Energy Management System. A concept for such a system, that is scalable by distributing it to multiple devices, is presented in this work. Reconfiguration, such as changing the load distribution algorithm, can be realized without downtime. This is possible by implementing the concept as an IEC 61499 application. A field demonstrator is set up using embedded controllers, equipped with a network interface. To perform necessary measurement and switching tasks, an interface board is developed. The desired system behavior, a stable operation of a flexible autonomous power supply system, can be achieved in the simulation on PC hardware as well as on the field demonstrator set up.

Software-Enabled Investigation in Metaheuristic Power Grid Optimization

Actual developments in power grid research, analysis, and operation are dominated clearly by the strong convergence of electrical engineering with information technology. Hence, new control abilities in power grids come up that revolutionize traditional optimization issues, requiring novel solution methods. At the same time, heuristic algorithms have emerged to be highly capable of handling those new optimization problems. In this work, a simulation-based optimization approach is proposed that enables investigation with metaheuristic algorithms for domain experts, where especially the power engineering point of view gets highlighted. HeuristicLab is demonstrated as a framework for optimization, which facilitates usage and development of optimization algorithms in a way that is attractive not only to computer scientists. From a software point of view, architectural aspects are treated that enable the decoupling of optimization algorithms and problems, which is a basic fundament of the framework. Further, interprocess communication is discussed that enables the interaction of optimization algorithms and simulation problems, and a practical showcase demonstrates the frameworks application to real-world power grid optimization issues.