Lars Evertz

Laying a basis for service systems in process control

To meet the flexibility demands introduced by modern markets, process plants have to become more flexible themselves. To tackle this issue and to ease vertical integration of IT-systems in enterprises a service-oriented approach is promising. Despite the developments concerning service-oriented architectures there is no standardized interface for service systems in process control systems. Therefore, in this paper we lay a basis for service systems in process control. We propose a message format and a way to describe services. We show which actions of a service interaction sequence have to be done in the engineering phase and which can be done at runtime. This is needed to meet non-functional requirements of control applications. The overall aim of the service system is to enhance flexibility without creating new dependencies.

A Hands-On Laboratory on Industrial Hardware, Process Control and Advanced Automation

Abstract The field of process control comprises a wide set of functions along the life-cycle and through all levels of the automation system pyramid. To give students a glance of the complexity of process control it is important to provide the possibility to try as much functionality as possible at own hand. That is why the practice on industrial relevant hard- and software should be an important part of control education. Beside theoretical basics given in lectures, study trips to industrial plants and deepening loop-control-laboratories a laboratory along the levels of the automation pyramid as well as along the life-cycle of a plant give the students the big picture of process automation. This paper presents the challenges, requirements and concepts for such a laboratory. The presentation of the resulting laboratory plant (M3P.AC) as well as a field report about five years ongoing labs finalize the paper.

Teaching Cascaded Controllers with a Fuel Cell Plant in a Hands-On Laboratory

Abstract It is generally accepted that practical experience has a positive effect on the learning process. Hence, a hands-on laboratory is a main pillar of the education concept of the Chair for Process Control Engineering, RWTH Aachen University. The topic of cascaded controllers was added to the lecture “Process Control Engineering” recently. The behaviour of these controllers is not trivial to imagine. Therefore, the hands-on laboratory is a predestined way to deepen the students’ knowledge and build up a basic image of the correlations. In this paper we show how the hands-on laboratory is extended to include the new topic. We will introduce a fuel cell plant which is build up in the laboratory for the new experiments and show how these experiments are fit into the overall laboratory course.

Semi-automatic development of service adaptors from property-based service descriptions

Interoperability is a key feature in todays IT-Environments. To achieve interoperability, the users actions when connecting two different systems have to be minimized. For this reason, several service based systems have been developed. However, as far as the current implementations in the field are concerned, all of them need connectors and gateways that are individually developed to connect heterogeneous components. In this contribution we develop a description scheme for services that is split into a semantic and a structural part. This enables a semi-automatic generation of such adaptors and establishes interoperability. The description scheme is based on properties which are defined in decentralized repositories. An example implementation for the adaptor-development process is shown.