Ontology-Based OPC UA Data Access via Custom Property Functions

Accessing and Interpreting OPC UA Event Traces based on Semantic Process Descriptions

“…These CPF extend the SPARQL query evaluator of the Apache Jena Framework with custom code, that gets executed whenever the CPF gets called in a query. In order to avoid overloading the triple store, the OPC UA data is stored in a separate database and only accessed on-demand [13]. It succeeds in accessing the recorded values.…”

“…While there are many approaches to model static information about CPPS, no method of accessing segments of timeannotated sensor data based on this information exists. This work therefore aims to close the gap between the approach to ontology modeling from Hildebrandt et al [10] and the data access to logged OPC UA data from Steindl et al [13]. The approach from Hildebrandt et al [10] is used to formalize prior knowledge about the structure and processes of a CPPS.…”

“…The approach from Hildebrandt et al [10] is used to formalize prior knowledge about the structure and processes of a CPPS. Based on this process description, process-based event traces can be extracted using the approach from Steindl et al [13].…”

“…Multiple approaches for access to this type of data exist in the literature, among them Virtual Knowledge Graphs [11] or CPFs. For this use case a CPF was chosen following the approach from [13]. Further information on the implementation can be found in Section IV.…”

“…To allow direct access from the ontology, the approach by Steindl et al [13] was modified. As in [13], a custom property function was registered as an extension in Apache Jena's SPARQL processor ARQ.…”