Publikation
Bidirectional Transformation of MES Source Code and Ontologies
Badarinath Katti; Christiane Plociennik; Martin Ruskowski; Michael Schweitzer
In: Procedia Manufacturing, Vol. 42, Pages 197-204, Elsevier, 2020.
Zusammenfassung
Future production environments must be flexible and reconfigurable. To achieve this, the devices and services to fulfill the different steps of a production order (PO) should not be selected in the manufacturing execution system (MES), but in an edge component close to the shop floor. To enable this, abstract services in the PO and concrete services provided by the field devices on the shop floor need to refer to a production ontology. The creation of this ontology is a challenge of its own. This research proposes a pragmatic automation of an encoding of a primary and light weight production ontology based on the source code of MES. The transformation procedure of source code to resource, product and generic concepts of the manufacturing plant ontology is described. To this end, the knowledge of OPC UA collaborations are also exploited during the creation of resource ontologies. Due to a fundamental difference between source code implementation (imperative paradigm) and ontology representation (declarative paradigm), the problem of information loss is inevitable. This problem is overcome by formulation of production and business rules that encapsulate the logic of the MES. The foundation of ontology is exploited to formulate these rulesets using OWL based constructs and OWL based rule languages such as Semantic Web Rule Language (SWRL), Semantic Query-Enhanced Web Rule Language (SQWRL) and SPARQL Protocol and RDF Query Language (SPARQL) based on feasibility and requirements of specific rules. Further, these rulesets are either run on the automatically generated ontology at design time with an intention to enrich the knowledge base, or production runtime to validate the pre-defined business rules between the production steps. The generated ontology also acts as basis for automatically generating the OWL-S ontologies for the OPC UA application methods for the purpose of dynamic manufacturing service discovery and orchestration. The generated ontology and an abstract PO hooked with formulated rules are cached to the shop-floor network for consequent production control to enable smart edge production. An implementation is conducted on an industrial use-case demonstrator to evaluate the applicability of the proposed approach.