A Digital Twin Platform for Industrie 4.0
In an Industrie 4.0 (I4.0), rigid structures and architectures applied in manufacturing and industrial information technologies today will be replaced by highly dynamic and self-organizing networks. Today’s proprietary technical systems lead to strictly defined engineering processes and value chains. Interacting Digital Twins (DTs) are considered an enabling technology that could help increase flexibility based on semantically enriched information. Nevertheless, for interacting DTs to become a reality, their implementation should be based on open standards for information modeling and application programming interfaces like the Asset Administration Shell (AAS). Additionally, DT platforms could accelerate development and deployment of DTs and ensure their resilient operation. This chapter develops a suitable architecture for such a DT platform for I4.0 based on user stories, requirements, and a time series messaging experiment. An architecture based on microservices patterns is identified as the best fit. As an additional result, time series data should not be integrated synchronously and directly into AASs, but rather asynchronously, either via streams or time series databases. The developed DT platform for I4.0 is composed of specialized, independent, loosely coupled microservices interacting use case specifically either syn- or asynchronously. It can be structured into four layers: continuous deployment, shop-floor, data infrastructure, and business services layer. An evaluation is carried out based on the DT controlled manufacturing scenario: AAS-based DTs of products and manufacturing resources organize manufacturing by forming highly dynamic and self-organizing networks. Future work should focus on a final, complete AAS integration into the data infrastructure layer, just like it is already implemented on the shop-floor and business services layers. Since with the standardized AAS only one interface type would then be left in the DT platform for I4.0, DT interaction, adaptability, and autonomy could be improved even further. In order to become part of an I4.0 data space, the DT platform for I4.0 should support global discovery, data sovereignty, compliance, identity, and trust. For this purpose, Gaia-X Federation Services should be implemented, e.g., as cross-company connectors.