This paper addresses indoor localization using an anchor-based system based on Bluetooth Low Energy (BLE) 5.0 technology, adopting the Received Signal Strength Indicator (RSSI) for the distance estimation. Different solutions have been proposed in the scientific literature to improve the performance of this localization technology, but a detailed performance comparison of these solutions is still missing. The aim of this work is to make an experimental analysis combining different solutions for the performance improvement of BLE-based indoor localization, identifying the most effective one. The considered solutions involve different RSSI signals’ conditioning, the use of anchor–tag distance estimation techniques, as well as approaches for estimating the unknown tag position. An experimental campaign was executed in a complex indoor environment, characterized by the continuous presence in the movement of working staff and numerous obstacles. The exploitation of multichannel transmission using RSSI signal aggregation techniques showed the greater performance improvement of the localization system, reducing the positioning error (from 1.5 m to about 1 m). The other examined solutions have shown a lesser impact in the performance improvement with a decrease or an increase in the positioning errors, depending on the considered combination of the adopted solutions.

The shop floor or factory floor is the area inside a factory where manufacturing production is executed. The digitalisation of this area has been increasing in the last few years, introducing the Digital Twin (DT) and the Industry 4.0 concepts. A DT is the digital representation of a real object or an entire system. A DT includes a high diversity of components from different vendors that need to interact with each other efficiently. In most cases, the development of standards and protocols does not consider the need to operate with other standards and protocols, causing interoperability issues. Transducers (sensors and actuators) use the communication layer to exchange information with digital contra parts, and for this reason, the communication layer is one of the most relevant aspects of development. This paper covers DT development, going from the physical to the visualisation layer. The reference architecture models, standards, and protocols focus on interoperability to reach a syntactic level of communication between the IEEE 1451 and the IEC 61499 standards. A semantic communication layer connects transducer devices to the digital representation, achieving a semantic level of interoperability. This communication layer adds semantics to the communication process, allowing the development of an interoperable DT based on the IEEE 1451 standards. The DT presented reaches the syntactic and semantic levels of interoperability, allowing the monitoring and visualisation of a prototype system.

Industrial Internet of Things focuses on the manufacturing process and connects with other associated concepts such as Industry 4.0, Cyber-Physical Systems, and Cyber-Physical Production Systems. Because of the complexity of those components, it is necessary to define reference architectures models to manage Industry 4.0 and the Industrial Internet of Things. The reference architecture models aim to solve the interoperability problem enabling the syntactical and semantic levels of interoperability. A reference architecture model provides a bottom/top view of an industrial process, from the physical transducers at the physical layer to the business layer. The physical layer provides access to a twin representation of a physical thing in the digital world, extending the functionalities in the manufacturing process. This paper studies the syntactic interoperability between the IEEE 1451 and IEC 61499 in an industrial environment. The IEEE 1451 family of standards has the essential characteristics to support the information exchange between smart transducers (sensors and actuators), building the digital elements and meeting the Industry 4.0 requirements. The IEC 61499 standard enables industrial control and automation. These two standards combined at the syntactic level solve an interoperability problem. The IEC 61499 also provides data to the framework layer, supplying all the parameters defined for the communication layer specified by a reference architecture model. This paper combines the IEEE 1451 with the IEC 61499, enabling data exchange in a reference architecture model proposed for Industry 4.0. Network performance at the communication level of a reference architecture model in a local network and an external network is evaluated for the proposed application. The IEEE 1451 standard implementation and adoption to acquire data and communicate it inside an industrial process allowed the IEC 61499 standard to control an industrial process. The IEEE 1451 standard is implemented in a MSP430 low power microcontroller. A Raspberry Pi running FORTE and 4diac in the USA and Portugal were used to test a local network in Portugal and an external network in USA. Data related to network performance was obtained with Wireshark and processed with MATLAB. Tests using the Message Queuing Transport Telemetry Transport and Hypertext Transport Protocols verified the performance of these protocols, supported by the IEEE 1451 and IEC 61499 standards, showing that communication inside an Industry 4.0 environment is possible. MQTT protocol is faster, has a small packet size, and consumes less bandwidth. The HTTP protocol uses more bandwidth but is more reliable for real-time communication, essential for Industry 4.0.

The increasing demand for IoT solutions in smart cities, coupled with the increasing use of sensors and actuators and automation in these environments, has highlighted the need for efficient communication between Internet of Things (IoT) devices. The success of such systems relies on interactions between devices that are governed by communication protocols which define how information is exchanged. However, the heterogeneity of sensor networks (wired and wireless) often leads to incompatibility issues, hindering the seamless integration of diverse devices. To address these challenges, standardisation is essential to promote scalability and interoperability across IoT systems. The IEEE 1451 standard provides a solution by defining a common interface that enables plug-and-play integration and enhances flexibility across diverse IoT devices. This standard enables seamless communication between devices from different manufacturers, irrespective of their characteristics, and ensures compatibility via the Transducer Electronic Data Sheet (TEDS) and the Network Capable Application Processor (NCAP). By reducing system costs and promoting adaptability, the standard mitigates the complexities posed by heterogeneity in IoT systems, fostering scalable, interoperable, and cost-effective solutions for IoT systems. The IEEE 1451 standard addresses key barriers to system integration, enabling the full potential of IoT technologies. This paper aims to provide a comprehensive review of the challenges transducer networks face around IoT applications, focused on the context of smart cities. This review underscores the significance and potential of the IEEE 1451 standard in establishing a framework that enables the harmonisation of IoT applications. The primary contribution of this work lies in emphasising the importance of adopting the standards for the development of harmonised and flexible systems.

The fourth industrial revolution is supported by concepts such as the Internet of Things and Cyber-Physical Systems. Introducing these concepts, a digital representation of the factory and the production process is possible. As a consequence of this industrial revolution, the manufacturing processes can react to a specific request received from a client, rapidly implementing changes in the production chain, adapting itself to the new demands. Therefore, the smart factory is characterized by its great agility and flexibility. To achieve this goal, standards have been developed at different levels. The work of developing a new standard does not end with its approval and publishing. It should be known to industrial agents, who through educational examples, will identify the standard's potential application and advantages. This paper presents a platform to support educational, development and validation activities, and contribute to disseminating the IEEE 1451 family of standards. The platform was developed using commercially accessible platforms and open-source tools, making it suitable for academic and research use.

The evolution of Information and Communication Technologies and the increasing smartness of instrumentation is leading the industrial sector to evolve and reach the 4th generation of the industry. The standardization will support the technological evolution leading the industry to the Factory of the Future. The IEEE 1451 family of standards was developed to enhance the implementation of Wireless Sensor Networks (WSN) able to communicate with the network, and so lead to the Internet of Things. In several phases of product development, the control and measurement tasks are needed and WSN can be implemented to reduce men hours and increase the accuracy of the measurements. In this context, this paper discusses a wireless sensor network in an automotive factory environment, and presents how the standard can be applied to the painting process. This is a work in progress, so in this paper is discussed the implementation of the family of standards and what are the advantages of using standardized sensor networks.