On the Use of LoRaWAN for Indoor Industrial IoT Applications

Low-Power Wide-Area Networks (LPWANs) have recently emerged as appealing communication systems in the context of the Internet of Things (IoT). Particularly, they proved effective in typical IoT applications such as environmental monitoring and smart metering. Such networks, however, have a great potential also in the industrial scenario and, hence, in the context of the Industrial Internet of Things (IIoT), which represents a dramatically growing field of application. In this paper we focus on a specific LPWAN, namely, LoRaWAN, and provide an assessment of its performance for typical IIoT employments such as those represented by indoor industrial monitoring applications. In detail, after a general description of LoRaWAN, we discuss how to set some of its parameters in order to achieve the best performance in the considered industrial scenario. Subsequently we present the outcomes of a performance assessment, based on realistic simulations, aimed at evaluating the behavior of LoRaWAN for industrial monitoring applications. Moreover, the paper proposes a comparison with the IEEE 802.15.4 network protocol, which is often adopted in similar application contexts. The obtained results confirm that LoRaWAN can be considered as a strongly viable opportunity, since it is able to provide high reliability and timeliness, while ensuring very low energy consumption

Assessment of a Vision-Based Technique for an Automatic Van Herick Measurement System

The adoption of artificial intelligence (AI) methods within the instrumentation and measurements field is nowadays an attractive research area. On the one hand, making machines learn from data how to perform an activity, rather than hard code sequential instructions, is a convenient and effective solution in many modern research areas. On the other hand, AI allows for the compensation of inaccurate or not complete models of specific phenomena or systems. In this context, this article investigates the possibility to exploit suitable machine learning (ML) techniques in a vision-based ophthalmic instrument to perform automatic anterior chamber angle (ACA) measurements. In particular, two convolutional neural network (CNN)-based networks have been identified to automatically classify acquired images and select the ones suitable for the Van Herick procedure. Extensive clinical trials have been conducted by clinicians, from which a realistic and heterogeneous image dataset has been collected. The measurement accuracy of the proposed instrument is derived by extracting measures from the images of the aforementioned dataset, as well as the system performances have been assessed with respect to differences in patients' eye color. Currently, the ACA measurement procedure is performed manually by appropriately trained medical personnel. For this reason, ML and vision-based techniques may greatly improve both test objectiveness and diagnostic accessibility, by enabling an automatic measurement procedure

Industrial Wireless Sensor Networks - Simulation and measurement in an interfering environment

Recently the research community is considering with a growing interest the adoption of IWSNs in application contexts such as real-time (industrial) communications and distributed measurement systems. These types of applications typically impose very tight equirements to the underlying communication systems and, moreover, they might have to cope with the intrinsic unreliability of wireless networks. It is hence needed an accurate characterization of these networks' behavior, from a metrological point of view. Suitable measurement systems have to be realized, and experiments performed aimed at evaluating some of the most appropriate performance indicators. Unfortunately, despite the appealing opportunities provided by IWSNs, their adoption is just at its beginning. It is clear that a comprehensive experimental analysis of their behavior would improve theoretical analysis, simulations and design of the network, since the consequent increased accuracy of models could reduce the source of difference between real and expected behaviors. With the work presented in this thesis the author would provide some original contribution in the field of measurements on real-time wireless networks adopted for industrial communications and distributed measurement systems. In this context, one of the most relevant aspect to be considered is represented, as described in the literature, by interference that possibly arises from "intentional" communications taking place in external systems. In order to address such an issue, some simulation techniques have been considered. As a result, they lead to the development of a network simulator software tool that enabled a cross-layer analysis of interference. This activity stimulated an in-depth study of the IEEE 802.15.4 and IEEE 802.11 communication protocols. Particularly, medium access techniques have been analyzed in the perspective of IWSN applications. On this basis new and effective methods for increasing the network reliability have been proposed, along with fair packet retransmission scheduling methods. Moreover, new rate adaptation algorithms for wireless networks specifically designed for real-time communication purposes, exploiting the high robustness of low transmission rates have been proposed. Finally, since the reliability of a network strongly depends on the real behavior of the employed devices, an experimental approach for the measurement of the devices characteristics is presented, with the aim of providing suitable models and methods for designers.La comunità scientifica, recentemente, sta considerando con sempre maggiore interesse l'adozione di reti di sensori wireless in contesti come le comunicazioni real-time (industriali) e i sistemi di misura distribuiti. Queste applicazioni richiedono tipicamente, al sistema di comunicazione, di soddisfare requisiti molto stringenti, considerando anche l'intrinseca inaffidabilità del canale radio. Risulta quindi necessaria un'accurata caratterizzazione, in termini metrologici, del comportamento di questa tipologia di reti, tramite sistemi di misura adatti alla valutazione dei più appropriati indici di prestazioni. Sfortunatemente, infatti, l'impiego di questi sistemi è ancora agli inizi, nonostante le interessanti prospettive applicative fornite dalle reti wireless real-time. Appare quindi chiaro come un'accurata caratterizzazione sperimentale del loro comportamento reale migliorerebbe sensibilmente l'efficacia delle analisi teoriche, delle simulazioni e di conseguenza del progetto della rete, risultando incrementata l'accuratezza dei modelli teorici e limitate le sorgenti di deviazione tra i risultati attesi e quelli sperimentali. Con il lavoro presentato in questa tesi, l'autore intende fornire contributi originali nel campo delle misure sulle reti wireless real-time adottate per comunicazioni industriali e sistemi di misura distribuiti. In questo contesto, uno dei principali aspetti da considerare, come si evince dalla letteratura, è dato dall'interferenza dovuta a comunicazioni "intenzionali" da parte di sistemi esterni. Per affrontare quest'analisi si sono inizialmente valutate alcune tecniche di simulazione. Questo ha portato allo sviluppo di un software di simulazione per reti di comunicazione specificamente progettato per l'analisi cross-layer dei fenomeni d'interferenza. Quest'attività ha stimolato uno studio approfondito dei protocolli di comunicazione IEEE 802.15.4 and IEEE 802.11. Nell'ottica del loro impiego per reti wireless real-time, particolare enfasi è stata rivolta alle tecniche di accesso al mezzo specificate nei citati standard. Sulla base di quest'analisi, sono stati proposti alcuni metodi originali per incrementare l'affidabilità di questi sistemi, considerando ad esempio nuove politiche di ritrasmissione per reti basate su polling ciclico. Inoltre sono stati proposti nuovi algoritmi per l'adattamento automatico del rate di trasmissione per reti IEEE 802.11, progettati per l'impiego specifico in un contesto di reti real-time. Infine, considerando che l'affidabilità di una rete in questo contesto dipende strettamente dal comportamento fisico dei componenti impiegati, viene proposto un approccio sperimentale per la misura e caratterizzazione dei ritardi introdotti dai dispositivi di rete, allo scopo di fornire metodi e modelli adeguati in un contesto di progettazione di rete

A Calibrated Test-Set for Measurement of Access-Point Time Specifications in Hybrid Wired/Wireless Industrial Communication †

In factory automation and process control systems, hybrid wired/wireless networks are often deployed to connect devices of difficult reachability such as those mounted on mobile equipment. A widespread implementation of these networks makes use of Access Points (APs) to implement wireless extensions of Real-Time Ethernet (RTE) networks via the IEEE 802.11 Wireless LAN (WLAN). Unfortunately, APs may introduce random delays in frame forwarding, mainly related to their internal behavior (e.g., queue management, processing times), that clearly impact the overall worst case execution time of real-time tasks involved in industrial process control systems. As a consequence, the knowledge of such delays becomes a crucial design parameter, and their estimation is definitely of utter importance. In this scenario, the paper presents an original and effective method to measure the aforementioned delays introduced by APs, exploiting a hybrid loop-back link and a simple, yet accurate set-up with moderate instrumentation requirements. The proposed method, which requires an initial calibration phase by means of a reference AP, has been successfully tested on some commercial APs to prove its effectiveness. The proposed measurement procedure is proven to be general and, as such, can be profitably adopted in even different scenarios

Energy Efficient Ethernet for the industrial communication scenario

none2nononeTramarin, Federico; Vitturi, StefanoTramarin, Federico; Vitturi, Stefan

A system architecture for distributed monitoring and control in a Smart Microgrid

The paper describes an architecture for a monitoring and control system that can be adopted in a Smart Micro Grid (SMG). The logical framework is firstly described, showing how the combined usage of Energy Gateways (EGs) and Energy Interfaces (EIs) will provide new interesting features to the grid. Then, the expected capabilities from the SMG components are discussed, providing a high level definition and analysis of both EGs' and EIs' requirements. A distributed monitoring and control system is then described based on the presented vision, highlighting critical requirements. Finally, a prototype system has been realized using embedded components. The provided experiments constitute a proof of concepts about the expected features of the SMG