Digital Twins: Modeling Hierarchy and Basic Approaches

As a digital representation of physical entities, Digital Twins serve as powerful tools for bridging the gap between the physical and virtual realms. In this chapter, we explore the enabling technologies for creating accurate digital twin models. A three-layer digital twin modeling hierarchy is presented before introducing fundamental elements in digital twin construction: physics-based, data-driven, and geometrical models. This hierarchical structure is proposed aiming to connect the high-level digital twin objectives with concrete and case-specific modeling tools. By understanding these layers, practitioners can design effective digital twin models that facilitate the realization of digital twin goals while maximizing their added value. Meanwhile, digital twin modeling technologies are investigated and summarized, before discussing future research trends in this field.