| 1. |
- De Donato, Lorenzo, et al.
(author)
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Towards AI-assisted digital twins for smart railways : preliminary guideline and reference architecture
- 2023
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In: Journal of Reliable Intelligent Environments. - : Springer Science and Business Media Deutschland GmbH. - 2199-4668 .- 2199-4676.
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Journal article (peer-reviewed)abstract
- In the last years, there has been a growing interest in the emerging concept of digital twins (DTs) among software engineers and researchers. DTs not only represent a promising paradigm to improve product quality and optimize production processes, but they also may help enhance the predictability and resilience of cyber-physical systems operating in critical contexts. In this work, we investigate the adoption of DTs in the railway sector, focusing in particular on the role of artificial intelligence (AI) technologies as key enablers for building added-value services and applications related to smart decision-making. In this paper, in particular, we address predictive maintenance which represents one of the most promising services benefiting from the combination of DT and AI. To cope with the lack of mature DT development methodologies and standardized frameworks, we detail a workflow for DT design and development specifically tailored to a predictive maintenance scenario and propose a high-level architecture for AI-enabled DTs supporting such workflow.
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| 2. |
- Barile, Gianluca, et al.
(author)
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A standard CMOS bridge-based analog interface for differential capacitive sensors
- 2017
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In: PRIME 2017 - 13th Conference on PhD Research in Microelectronics and Electronics, Proceedings. - : IEEE. - 9781509065073 ; , s. 281-284
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Conference paper (peer-reviewed)abstract
- This work describes an analog electronic interface, based on a modified De Sauty AC bridge, performing a differential capacitive sensor estimation. A suitable feedback loop tunes a Voltage Controlled Resistor to balance the bridge. The electronic circuit has been designed in a standard integrated CMOS technology (AMS 0.35μm) with a low supply voltage (±1.5 V) and a reduced power consumption (lower than 4mW). PSpice simulation results show a very good agreement with theoretical expectations. The output voltage accuracy shows a 0.03V maximum absolute error for a range of ±50% of sensor variations from its baseline value. Very small baseline values are allowed (tens of μF).
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| 3. |
- Barile, Gianluca, et al.
(author)
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Linear Integrated Interface for Automatic Differential Capacitive Sensing
- 2017
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In: Proceedings, Volume 1, Eurosensors 2017. - Basel Switzerland : MDPI.
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Conference paper (other academic/artistic)abstract
- In this work, the authors introduce a new full-analog front-end for differential capacitance sensors which provides a DC output voltage, directly proportional to the measurand variations. The readout circuit architecture is based on a De Sauty bridge as core of the capacitive sensing whereas the feedback circuitry performs the bridge autobalancing operation by means of changes in a multiplier output. The circuit is designed in a standard CMOS technology (AMS 0.35 µm) so is suitable for portable systems. Simulated results have shown a good agreement with the theoretical model being the percentage relative error less than 2.5%. Interface sensitivity is constant and values around 0.055 V/mm for the considered application.
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| 4. |
- Bonafini, Federico, et al.
(author)
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Exploiting localization systems for LoRaWAN transmission scheduling in industrial applications
- 2019
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In: 2019 15th IEEE International Workshop on Factory Communication Systems (WFCS). - : IEEE. - 9781728112688
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Conference paper (peer-reviewed)abstract
- The Internet of Things (IoT) paradigm contaminated industrial world, allowing for innovative services. The wireless communications seem to be particularly attracting, especially when complement indoor and outdoor Real Time Location Systems (RTLS) for geo-referencing smart objects (e.g. for asset tracking). In this paper, the LoRaWAN solution is considered for transmitting RTLS data. LoRaWAN is an example of Low Power Wide Area Network: it tradeoffs throughput with coverage and power consumption. However, performance can be greatly improved with limited changes to the standard specifications. In this work, a scheduling layer is suggested above the regular stack for allocating communication resources in a time slot channel hopping medium access strategy. The main innovation is the time synchronization, which is obtained opportunistically from the ranging devices belonging to the RTLSs. The experimental testbed, based on commercially available solutions, demonstrates the affordability and feasibility of the proposed approach. When low-cost GPS (outdoor) and UWB (indoor) ranging devices are considered, synchronization error of few microseconds can be easily obtained. The experimental results show the that time reference pulses disciplined by GPS have a maximum jitter of 180 ns and a standard deviation of 40 ns whereas, if time reference pulses disciplined by UWB are considered, the maximum jitter is 3.3 μs and the standard deviation is 0.7 μs.
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| 5. |
- Crema, Claudio, et al.
(author)
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Virtual Respiratory Rate Sensors : An Example of A Smartphone-Based Integrated and Multiparametric mHealth Gateway
- 2017
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In: IEEE Transactions on Instrumentation and Measurement. - 0018-9456 .- 1557-9662. ; 66:9, s. 2456-2463
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Journal article (peer-reviewed)abstract
- In the last few years, several wearables appeared in the market, for fitness and healthcare applications. Such smart devices have been proposed as a possible solution for lowering the costs of healthcare, leading to the mHealth revolution. In the typical scenario, each wearable, embedding sensors, processing units and communication modules, adopts a smartphone for data collection, data displaying, and remote communication. In this paper, authors modify this paradigm simplifying the wearables (e.g., relying only on simple analog front ends and communication interfaces) and exploiting the (relatively large) computational capability of the smartphone, not only for implementing gateway features but also for processing raw biosignals as well. Several experiments verify the feasibility of the proposed approach and demonstrate that 'local' biosensor virtualization is possible, expanding possibilities of mHealth. In particular, tests have been carried out to evaluate the performance of hearth rate computation and respiratory rate virtual sensor, starting from a single-lead electrocardiogram signal.
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| 6. |
- De Angelis, Alessio, et al.
(author)
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Performance Assessment of Chirp-Based Time Dissemination and Data Communications in Inductively Coupled Links
- 2017
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In: IEEE Transactions on Instrumentation and Measurement. - 0018-9456 .- 1557-9662. ; 66:9, s. 2474-2482
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Journal article (peer-reviewed)abstract
- Advantages of inductively coupled links for short-range communications are well known. Recently, they gained popularity as a viable solution for wireless power transmission. Interesting to notice that data communication capability is required as well, mainly for coordinating the transfer process. In this paper, the authors address the use of chirp signaling over inductively coupled links for both time dissemination and data communications. Such an approach extends field of applications, including data acquisition and instrumentation that are used in industrial automation. The effectiveness of the proposed approach is verified with extensive simulations and using a proof-of-concept prototype. Despite the prototype simplicity, jitter on the synchronizing reference signal is in the order of few microseconds and the bit error rate, over a short distance, is negligible.
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| 7. |
- Dirnfeld, Ruth, et al.
(author)
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Integrating AI and DTs : challenges and opportunities in railway maintenance application and beyond
- 2024
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In: Simulation (San Diego, Calif.). - : Sage Publications. - 0037-5497 .- 1741-3133.
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Journal article (peer-reviewed)abstract
- In the last years, there has been a growing interest in the emerging concept of digital twin (DT) as it represents a promising paradigm to continuously monitor cyber-physical systems, as well as to test and validate predictability, safety, and reliability aspects. At the same time, artificial intelligence (AI) is exponentially affirming as an extremely powerful tool when it comes to modeling the behavior of physical assets allowing, de facto, the possibility of making predictions on their potential evolution. However, despite the fact that DTs and AI (and their combination) can act as game-changing technologies in different domains (including the railways), several challenges have to be faced to ensure their effectiveness, especially when dealing with safety-critical systems. This paper provides a narrative review of the scientific literature on DTs for railway maintenance applications, with a special focus on their relationship with AI. The aim is to discuss the opportunities the integration of these two technologies could open in railway maintenance applications (and beyond), while highlighting the main challenges that should be overcome for its effective implementation.
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| 8. |
- Ferrari, Paolo, et al.
(author)
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On the use of LPWAN for EVehicle to grid communication
- 2017
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In: 2017 AEIT International Annual Conference. - : IEEE. ; , s. 1-6
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Conference paper (peer-reviewed)abstract
- The expected diffusion of EVehicles (EVs) to limit the impact of fossil fuel on mobility is going to cause severe issues to the management of electric grid. A large number of charging stations is going to be installed on the power grid to support EVs. Each of the charging station could require more than 100 kW from the grid. The grid consumption is unpredictable and it depends from the need of EVs in the neighborhood. The impact of the EV on the power grid can be limited by the proper exploitation of Vehicle to Grid communication (V2G). The advent of Low Power Wide Area Network (LPWAN) promoted by Internet Of Things applications offers new opportunity for wireless communications. In this work, an example of such a technology (the LoRaWAN solution) is tested in a real-world scenario as a candidate for EV to grid communications. The experimental results highlight as LoRaWAN technology can be used to cover an area with a radius under 2 km, in an urban environment. At this distance, the Received Signal Strength Indicator (RSSI) is about -117 dBm. Such a result demonstrates the feasibility of the proposed approach.
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| 9. |
- Rizzi, Mattia, et al.
(author)
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Evaluation of the IoT LoRaWAN Solution for Distributed Measurement Applications
- 2017
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In: IEEE Transactions on Instrumentation and Measurement. - 0018-9456 .- 1557-9662. ; 66:12, s. 3340-3349
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Journal article (peer-reviewed)abstract
- Internet of Things (IoT) is based on data collection, where billions of sensors sample the real world; in other words, the IoT includes a giant distributed measurement system (DMS). A question still requiring an answer is: Are the IoT technologies usable to enhance traditional measurement systems, since they have been developed for a very similar objective? In this paper, the use of a long-range (LoRa) technology, originally developed for IoT, is investigated with the aim of implementing DMSs. After the conclusion that LoRa and LoRa wide area network architectures show a good match with measurement systems, this paper focuses on the characterization of time-related performance indicators that are important for distributed systems. The experimental results show the capability of low-cost transceiver to schedule the transmission of frames with a standard uncertainty less than 3 μs; and an acceptable long-term clock stability (Allan Deviation) of commercial available devices (nodes and packet forwarders) for application such as smart metering, smart building, and process industry.
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| 10. |
- Rizzi, Mattia, et al.
(author)
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Using LoRa for Industrial Wireless Networks
- 2017
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In: 2017 IEEE 13th International Workshop on Factory Communication Systems (WFCS). - : IEEE. - 9781509057887
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Conference paper (peer-reviewed)abstract
- The new concept of Industry 4.0 has been developed: it includes both Internet of Things (IoT) structure and the local networks that are still needed to carry out real-time tasks. However, forecasts of mass application of consumer IoT system have stimulated the development of new wireless technologies that may also be interesting for industry. In this paper, the LoRa technology is investigated for the implementation of industrial wireless networks suitable for sensors and actuators of the Industry 4.0 era. After a brief overview of LoRa and LoRaWAN, the paper deals with the discussion about using LoRa for industrial applications compared to traditional industrial wireless systems. With only very light modifications to the upper layer of LoRaWAN communication stack, a time slot channel hopping schema is possible. The experimental results show the feasibility of the proposed approach, which is compatible with requirements of soft real-time applications in process industry. In particular, proper time, frequency, and spreading factor planning may allow 6000 nodes accessed up to one minute cycle time.
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