ENHANCING INTEROPERABILITY IN INDUSTRY 4.0

The research objectives of this thesis consists in the definition of innovative proposal to enhance interoperability in Industry 4.0, IIoT and IoT. The research was focused on the interoperability between communication protocols, due to the knowledge that adoption of communication standards are of paramount importance in Industry 4.0, IIoT and IoT. Furthermore, no one communication standard is globally accepted as reference standard in these contexts. Nevertheless, among the various standard taken in consideration in literature, OPC UA international standard (IEC 62541) seems to be one of the leading candidates to become a reference standard. As for example, "Reference Architecture Model for Industrie 4.0" (RAMI 4.0) indicates for OPC UA the role to standardise machine-to-machine communication. Another example is the "Industrial Internet Reference Architecture" (IIRA), defined by the Industrial Internet Consortium (IIC), where OPC UA plays a strategic role as it is one of the core connectivity standards. For this reason, the research has investigated the enhancement of interoperability in Industry 4.0, IoT and IIoT through improvements based on OPC UA. First of all, the research was focused on the realisation of a proposal enabling the interoperability between OPC UA and generic users not compliant with OPC UA standard; in particular, it has been assumed to propose a way to allow the interaction between OPC UA and devices or applications using web technologies and without any knowledge of the standard. The realization of this integration has been achieved through the definition of a novel data model mapping the OPC UA Information Model, based on common web data-formats (e.g. JSON). This proposal has been called Integration between OPC UA and the Web . After that, the research focus has been enlarged to propose a solution enabling the interoperability between OPC UA and IoT/IIoT ecosystems. Among the current IoT/IIoT ecosystems, OCF has been chosen for the integration with OPC UA, as it seems a promising solution to standardise the exchange of information into IoT as explained before. The solution mainly aims to realise a mapping between OPC UA and OCF information models and has been called Integration between OPC UA and OCF . Through this mapping, information maintained by an OPC UA Server may be used to populate a device compliant to OCF specifications which acts as a server, allowing it to expose this information to whatever client device in the OCF ecosystem. Vice versa, information maintained by an OCF Device may be published by an OPC UA Server allowing to make this information available to whatever OPC UA-compliant device.