Digital twin architecture and sim-to-real gap analysis of a material transfer system in a remanufacturing environment

This paper presents a digital twin architecture for a material flow system as well as experiments to determine the sim-to-real gap between virtual models and their real counterparts. The architecture comprises three layers, namely the physical/logical layer, the cyber layer as well as the descriptive layer. Virtual and real assets are able to communicate on the cyber layer by means of OPCUA and the Asset Administration Shell (AAS). The virtual models are implemented in a physics-based simulation environment and allow the reuse of all control and application layer software modules of their real counterpart. In addition, the sim-to-real gap between a selected asset, namely the Transfer Unit is analyzed by means of a collision analysis of the material transfer of simple shaped objects. The results show similar behavior of the real and the virtual models. However, more effort is needed to accurately model the meshes of the collision elements to ensure realistic results.