Gerhard Pratl

A New Model for Autonomous, Networked Control Systems

Existing communication utilities, such as the ISO/OSI model and the associated automation pyramid, have limitations regarding the increased complexity of modern automation systems. The introduction of profiles for fieldbus systems, or field-area networks (FANs), was an important innovation. However, in the foreseeable future the number of FAN nodes in building automation systems is expected to increase drastically. And here the authors see an opportunity to revolutionize the operation of intelligent, autonomous systems based on FANs. The paper introduces a system based on bionic principles to process the information obtained from a large number of diverse sensors. By means of multilevel symbolization, the amount of information to be processed is substantially reduced. A symbolic processing model is introduced that enables the processing of real world information, creates a world representation, and evaluates scenarios that occur in this representation. Two applications involving human actions in a building automation environment are briefly discussed. It is argued that the use of internal symbolization leads to greater flexibility in the case of a large number of sensors, providing the ability to adapt to changing sensor inputs in an intelligent way

Secure and reliable wide-area power-line communication for soft-real-time applications within REMPLI

The REMPLI project aims at designing and implementing a communication infrastructure for distributed data acquisition and remote control operation using the power grid as the communication medium. Aside of being a platform for automated meter reading with high time resolution, energy management and domotic applications, and the system provides status information about the power grid and its components, thus improving maintenance quality. In this paper we give an overview about the features and abilities of the REMPLI system, we show the system architecture, and we analyze the position of REMPLI in the market of power-line communication systems.

Implications of power-line communication on distributed data acquisition and control system

Automated meter reading, energy billing and energy management are applications that are based on and require remote access to control networks. Such applications are intrinsically linked to power-lines and as such suggest using the power distribution grid not only for energy transport but also as the communication medium. This paper describes a data acquisition and control system for energy distribution and consumption using power-lines and IP-based networks for communications. The primary application is meter reading with fine-grained resolution both in time and location of consumption. The paper describes the communication architecture and the services provided by the system and show how the peculiarities of especially the power-line communication influence the design of the interconnection between the two network types. Security aspects of the system are also discussed.

Scenario recognition in modern building automation

Abstract Modern building automation has to deal with very different types of demands, depending on the use of the building and therefore the persons acting within this building. To meet the demands of situation awareness in modern building automation, scenario recognition becomes more and more important to detect such demands and react to them. Two concepts of scenario recognition and their implementation will be introduced, one based on predefined templates and the other using an unsupervised learning algorithm using statistical methods. Implemented applications will be described and their advantages and disadvantages outlined. Copyright

Lessons learnt from Internet access to fieldbus gateways

Interconnections between fieldbus systems and IP-based networks have become a useful way to gain remote access to automation data. Current solutions are dominated by approaches based on Web technologies. The purpose of this paper is to demonstrate that there are alternatives and to report on experiences. In a case study, SNMP, LDAP, and SQL have been used as high-level access protocols. We review the architecture and typical functions of a gateway and discuss the mutual implications of the high-level protocol. The results from the case study suggest that none of the protocols is ideally suited for remote access due to shortcomings in either the protocol itself or the way data are described and managed. Therefore, proprietary solutions will persist.

Remote access to power-line networked nodes: digging the tunnel

The topic of connecting field area networks to remote applications by means of wide area networks (WAN), which are typically built on the Internet protocol (IP), is usually solved by introducing a component like a gateway, responsible for establishing the necessary communication link. Concepts for the design of such a gateway range from plain packet forwarding to complete protocol translations. This paper compares two concepts in this area applied on a power-line network (currently under development) and existing remote applications: the application layer gateway, which completely separates field area protocols and WAN protocols on all layers, and the tunnelling access point, which preserves the application layer protocol and only alters the way of transportation between the communication partners. The field area network under consideration is a power-line communication network; the WAN is any IP-based network, but preferably a private IP-network.

Perceptive awareness in building automation

In this paper, we introduce a system that uses a bionic approach to process the information obtained from a large number of diverse sensors. By means of the process of symbolization, the amount of information to be processed is drastically reduced, and used to create an inner representation of the real world. Three different applications involving human actions in a building are introduced and briefly discussed. It is argued that by making use of microsymbols, the proposed approach leads to greater flexibility, able to adapt to changing sensor inputs in an intelligent way.

Smart Nodes for Semantic Analysis of Visual and Aural Data

This paper proposes a system architecture that uses smart adaptive wireless networks of embedded sensing components to automatically detect uncommon or dangerous situations. The transformation of sensor values to semantic concepts enables the system to recognize predefined situation recognition and create a consistent world model between the nodes. It supports human operators of surveillance system and brings existing CCTV systems to the next level of machine-supported scenario detection.

A power line communication stack for metering, SCADA and large-scale domotic applications

This paper describes the communication stack of the REMPLI system: a structure using power-lines and IP-based networks for communication, for data acquisition and control of energy distribution and consumption. It is furthermore prepared to use alternative communication media like GSM or analog modem connections. The REMPLI system provides communication service for existing applications, namely automated meter reading, energy billing and domotic applications. The communication stack, consisting of physical, network, transport, and application layer is described as well as the communication services provided by the system. We show how the peculiarities of the power-line communication influence the design of the communication stack, by introducing requirements to efficiently use the limited bandwidth, optimize traffic and implement fair use of the communication medium for the extensive communication partners.

Simulation and visualization system for sensor and actuator data generation

Abstract The evolution of automation systems has reached a point where the increasing complexity requires new mechanisms to keep control of design and operation. In future all control systems will have to cope with massive data quantities that are collected from the environment. Such systems have to react based on the recognition of whole scenarios. In this paper we present a simulation tool, which is able to generate big amounts of sensor data in an animated, virtual environment. This data is used by two different systems to verify their accuracy.