Читать книгу Cyber-physical Systems - Pedro H. J. Nardelli - Страница 27

Systems that manifest themselves in a material form are classified as material systems. They are composed of concrete components. Conceptual systems exist in a symbolic domain as plans, drawings, schemes, equations, specifications, or computer simulations used to create, produce, or improve material systems. Conceptual systems can also be concrete in some cases when a given material system is emulated on smaller scales or with elements of similar properties; in this case, a conceptual system is also a material system. There is also a possibility of hybrid material‐conceptual systems as, for example, hardware‐in‐the‐loop simulation platforms [3]. Further, the idea of digital twins can be seen as a hybrid system where there is a one‐to‐one map between an operating material system and its symbolic counterpart [4]. These last two approaches indicate some features of cyber‐physical systems, but we are not yet ready to understand what cyber theoretically means.

Example 2.5 The wind turbine presented in Example 2.3 serves as an illustration of all cases. It is first a purely conceptual system where the components with their attributes are combined on paper based on dynamical equations, and it is then tested in a specialized computer simulator. The second phase is prototyping and a proof‐of‐concept phase on a small scale. This emulation of the material system to be produced is still conceptual as it is not implemented in its real conditions. The real wind turbine tested under controlled conditions, not yet connected to the real grid but to a virtual emulator building a hardware‐in‐the‐loop simulation, is a hybrid conceptual‐material system. The wind turbine in the field is a material system. If its operation is monitored and its operating behavior related to its digital twin, then we have another kind of hybrid system.