An architecture for coupled digital twins with semantic lifting

To enable the reuse of Digital Twins, in the form of simulation units or other forms of behavioral models, of single physical components, one must be able to connect and couple them. Current platform and architectures consider mostly monolithic digital twins and offer little support for coupling and checking the consistency of the coupling. The coupling must be internally consistent—satisfy constraints related to their co-simulation—and externally consistent—mirror the structure of the composed physical system. In this paper, we propose an extension to a behavior-extended Digital Twin architecture for individual Digital Twins to include co-simulation scenarios for coupled systems lifted from configuration files, which can be implemented along with a Digital-Twin-as-a-Service platform to make assets reusable in time. To monitor and query these connections, we introduce a semantic lifting service, which interprets the coupled Digital Twins as Knowledge Graphs and enables the use of queries to express internal and external consistency constraints. Two representative case studies for systems with coupled behavior are used for the demonstration of this approach and show that it indeed enables reusability of components and services between different Digital Twins.