During the research cruise AL547 with RV ALKOR (October 20-31, 2020), a collaborative underwater network of ocean observation systems was deployed in Boknis Eck (SW Baltic Sea, German exclusive economic zone (EEZ)) in the context of the project ARCHES (Autonomous Robotic Networks to Help Modern Societies). This network was realized via a Digital Twin Prototype approach. During that period different scenarios were executed to demonstrate the feasibility of Digital Twins in an extreme environment such as underwater. One of the scenarios showed the collaboration of stage IV Digital Twins with their physical counterparts on the seafloor. This way, we address the research question, whether Digital Twins represent a feasible approach to operate mobile ad hoc networks for ocean and coastal observation.

In this decade, the amount of (industrial) Internet of Things devices will increase tremendously. Today, there exist no common standards for interconnection, observation, or the monitoring of these devices. In context of the German "Industrie 4.0" strategy the Reference Architectural Model Industry 4.0 (RAMI 4.0) was introduced to connect different aspects of this rapid development. The idea is to let different stakeholders of these products speak and understand the same terminology. In this paper, we present an approach using Digital Twins to prototype different layers along the axis of the RAMI 4.0, by the example of an autonomous ocean observation system developed in the project ARCHES.

Digital Twins may be employed for developing embedded software and can be classified in three subcategories by their level of integration with the corresponding physical objects/twins. We introduce and report on experience with a new category: the Digital Twin Prototype. Digital Twin Prototypes support engineers to test embedded software systems, without the need of a connection to a physical object. In CI/CD pipelines they can be used for integration testing and thus, allow for an agile verification and validation process. We developed and evaluated this approach to create an underwater network of ocean observation systems. The feasibility was shown in a demonstration mission in the Baltic Sea in October 2020.

Digital Twins may be employed for developing embedded software and can be classified in three subcategories by their level of integration with the corresponding physical objects/twins. We introduce and report on experience with a new category: the Digital Twin Prototype. Digital Twin Prototypes support engineers to test embedded software systems, without the need of a connection to a physical object. In CI/CD pipelines they can be used for integration testing and thus, allow for an agile verification and validation process. We developed and evaluated this approach to create an underwater network of ocean observation systems. The feasibility was shown in a demonstration mission in the Baltic Sea in October 2020.