Stephan Hensel

Open Semantic Revision Control with R43ples: Extending SPARQL to access revisions of Named Graphs

The Semantic Web provides mechanisms to interlink data in a fast and efficient way and build complex information networks. However, one of the most important features missing for industrial application is version control which allows recording changes and rolling them back at any time if necessary. It is not sufficiently supported by todays triplestores and recent version control systems are not very well integrated into the Semantic Web. This paper shows a way of dealing with version and revision control using SPARQL. It presents R43ples as an approach using named graphs for semantically storing the differences between revisions. Furthermore it allows a direct access and manipulation of revisions with extended version of SPARQL. Smart mechanisms for restoring old revisions relying on query rewriting provide a fast way of querying old revisions of big datasets. A prototypical implementation of the system prove an appropriate performance under different conditions.

Model-based engineering of CPPS in the process industries

Most Cyber Physical Production Systems (CPPS) research is devoted to the manufacturing industry, but the need for flexibility is an increasing trend in the process industry, too. Todays process automation systems (PAS) are not well-suited for quick adaptation of the plant, i.e. the addition, removal or change of physical components, such as filters, mixers, or reaction units. The authors have developed a model-based approach, which allows reconfiguring the PAS based on a model, which acts as a representative of the physical component. Thus, the model and the physical component together form a CPPS. In the paper, the requirements, the model structure, and the model content will be described, and a practical example will be presented.

Co-simulation with OPC UA

Engineering projects are driven by cost and time constraints. Furthermore, the increasing complexity of these projects makes it necessary to expose specification, implementation and conceptual errors as early as possible. Therefore, a well-established method is to carry out simulation experiments. This paper presents a concept for coupling already existing (domain-specific) simulation models that allow the integration of individual models in a co-simulation environment. A complete system simulation can take place in this environment. Therefore, the contribution of OPC UA as a generic middleware technology — a candidate for Industrie 4.0 scenarios that is being intensively discussed — is analysed. Through a prototypical implementation based on open62541, we can show a proof of concept by coupling different simulations (SIMIT and FMI instances). It also shows that our concept can be easily extended regarding the integration of new simulators.

Concept for the detection of virtual functional modules in existing plant topologies

The design of conventional process plants is guided by the idea of structuring the process in functional units. Because of cost reduction this design is often neglected during the implementation phase. There is a huge potential in the re-modularization looking at the re-usability which directly effects the engineering efficiency when developing new plants. Furthermore, there is the possibility to create modularized KPIs. Those can be aggregated to plant-wide KPIs to evaluate the overall plant performance and status. In this paper the authors are presenting a concept for the detection of virtual modules in existing plant topologies. The plant topology is therefore transformed into a searchable graph. With the help of extended search algorithms and the definition of functional patterns it is now possible to identify all possible virtual module within a plant topology. Through a prototypical implementation, visualizing the identified modules in the graph, a proof of concept is shown.