Alessandra Flammini - Academia.edu (original) (raw)

Papers by Alessandra Flammini

Research paper thumbnail of Assessment of Time Performance of Lightweight Virtualization for Edge Computing Applications

Research paper thumbnail of A proof of concept application of sensing technologies for managing proximity hazards on construction sites

Proceedings of the 38th International Symposium on Automation and Robotics in Construction (ISARC), 2021

The proceedings series is Scopus indexed.

Research paper thumbnail of A standard CMOS bridge-based analog interface for differential capacitive sensors

2017 13th Conference on Ph.D. Research in Microelectronics and Electronics (PRIME), 2017

This work describes an analog electronic interface, based on a modified De Sauty AC bridge, perfo... more 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).

Research paper thumbnail of On the use of LPWAN for EVehicle to grid communication

2017 AEIT International Annual Conference, 2017

The expected diffusion of EVehicles (EVs) to limit the impact of fossil fuel on mobility is going... more 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.

Research paper thumbnail of Enhanced flexible LoRaWAN node for industrial IoT

2018 14th IEEE International Workshop on Factory Communication Systems (WFCS), 2018

The Industrial Internet of Things (IIoT) is introducing the IoT approach in the industrial automa... more The Industrial Internet of Things (IIoT) is introducing the IoT approach in the industrial automation world, paving the way to innovative services for improving efficiency, reliability and availability of industrial processes and products. The IIoT takes advantage of the collection of large amount of data by means of (wireless) links connecting smart sensors attached to the system of interest. Low Power Wide Area Networks emerged as a viable solution for implementing private cellular like communications. In this paper, the LoRaWAN technology is addressed, thanks to the wide acceptance it received in both industrial and academic worlds. In particular, an enhanced node is proposed as a building block of IIoT-enabled industrial wireless networks. It offers new features: it behaves as a regular node; it can act as a gateway toward legacy/different (wired) networks; and it can extend LoRaWAN coverage acting as a range extender (i.e. a single hop forwarder). After a brief overview of LoRa and LoRaWAN, the paper deals with the features of the realized node, exploiting commercially available hardware. The experimental results show the feasibility of the proposed approach. In particular, the range extender capability of transmitting replicas of an incoming messages is tested for different transmission delays.

Research paper thumbnail of Improving Redundancy in LoRaWAN for Mixed-Criticality Scenarios

IEEE Systems Journal, 2021

Most Internet of Things applications rely on wireless communication, which ensures flexibility an... more Most Internet of Things applications rely on wireless communication, which ensures flexibility and scalability. However, an increasing number of these applications have real-time constraints and require mixed-criticality. Indeed, the complexity of distributed systems necessarily calls for data exchanges with different priorities and different failure handling. The design of a reliable protocol supporting different traffic priorities must take into account external interferences that can inevitably affect radio links. This article focuses on LoRaWAN, the currently most famous example of low power wide area network technology. In particular, redundant transmissions offered by the proposed LoRa-REP strategy enhance the communication resilience of sporadic critical message transaction (consisting of message uplink and acknowledgment downlink). The implementation by means of “virtual nodes” assures compatibility with legacy deployments (preserving investments) and offers easy scalability. Experimental results obtained with purposely designed test bench confirm the advantages of the proposed solution in a real-world scenario. Notably, the failure probability of a critical transaction drops from 78% of single spreading factor scenario to less than 2.5% with the proposed LoRa-REP.

Research paper thumbnail of A CMOS full-range linear integrated interface for differential capacitive sensor readout

Sensors and Actuators A: Physical, 2018

This manuscript presents the development of an integrated analog interface able to convert differ... more This manuscript presents the development of an integrated analog interface able to convert differential capacitive sensors variations into a DC voltage. The presented circuit exploits the architecture developed in previous works of the same authors, based on autobalancing bridge techniques, further improving its performances through the linearization of the input/output characteristic and the achievement of the full-range sensor variations capability. The interface takes advantage of Low Voltage and Low Power integrated circuit design techniques, optimizing performances for flux and force sensor. Simulated results with the AMS 0.35um standard CMOS technology have shown a very good agreement with the theoretical model developed, obtaining an error lower than 2.5% and a total power consumption of 5mW. Moreover, waiting for the chip production, a discrete element board has been also implemented and tested. Preliminary measurements on the test board have shown satisfactory input/output linearity characteristics with overall reduced percentage error (lower than 1.5%) in the measurand estimation.

Research paper thumbnail of Integrating remote sensors in a smartphone: The project "sensors for ANDROID in embedded systems

2016 IEEE Sensors Applications Symposium (SAS), 2016

Nowadays, smartphones integrate high quality sensors and communication systems, easily managed by... more Nowadays, smartphones integrate high quality sensors and communication systems, easily managed by simple APPs under Android. On the contrary, managing remote sensors requires a big effort in programming, both on the sensor and on the Smartphone side. In this work, a solution for filling this gap is proposed, providing the instruments to easily handle remote sensors, exactly as if they were embedded in Android environment. The work exploits the Bluetooth 4.0-4.1 technology and realizes a library for remote smart sensors managing. Two new tools are described: a framework, which allows the Android developers to handle the remote resources (i.e. sensors and actuators) with the same approach to the embedded resources; a tool for programming and addressing the resources of the remote sensors. The proposed architecture is experimentally evaluated in a possible scenario of home automation.

Research paper thumbnail of On the Use of Magnetically Coupled Resonators for Chirp-Based Timestamping

IEEE Transactions on Instrumentation and Measurement, 2015

The knowledge of the time value at which an event of interest occurred is the typical feature nee... more The knowledge of the time value at which an event of interest occurred is the typical feature needed to perform many kinds of postprocessing in distributed sensor networks. Consequently, network-based distributed systems must support time dissemination in order to ensure that relative clock errors among nodes remain below a certain threshold. Despite many protocols being well established for wired connections, the wireless sensor network paradigm required a new approach to address adverse characteristics of the wireless medium. In this paper, the adoption of low-frequency signaling is proposed for overcoming some issues of radio frequency transmissions when used for timestamping events. The proposed approach is characterized using numerical simulations and an experimental prototype, based on inductive coupling of tuned resonators. Experimental tests confirm the effectiveness and feasibility of this approach that achieves microsecond-order time recovery performance in practical system configurations.

Research paper thumbnail of First Conference on

Research paper thumbnail of An autonomous sensor with energy harvesting capability for airflow speed measurements

2010 IEEE International Instrumentation and Measurement Technology Conference, I2MTC 2010 - Proceedings, 2010

In several environments modest ambient airflows are present, for example, in airconditioning duct... more In several environments modest ambient airflows are present, for example, in airconditioning ducts, in outdoor environment, or in moving vehicles. Furthermore, an airflow speed measurement is an important indicator, for the energy efficiency in the regulation of the conditioning implants. An autonomous sensor placed in a duct and powered by an electromechanical generator scavenging energy from the airflow has been designed and tested. The airflow speed is measured trough the rotor frequency of the electromechanical generator. When the external readout unit is active the electromagnetic field is used to power the autonomous sensor system and transmit the data. A set of tests on three airflow harvesters using resistive loads was conducted to demonstrate their energy conversion potentials. An experimental system has been designed and realized demonstrating that the airflow harvester can power the autonomous sensor permitting airflow speed measurements.

Research paper thumbnail of Simple and Low-Cost Wireless Distributed Measurement System

This paper describes the design and realization of a simple and low-cost system for distributed m... more This paper describes the design and realization of a simple and low-cost system for distributed measurements. Traditional handheld digital multimeters have been equipped with a radio- frequency interface in order to implement what the authors call WDMM, the basic block of a wireless multi-probe data logger. New functionalities require very few components and result in a cost increase of less than 10$. In addition, also maintenance has been facilitated since tracking data such as working state or last calibration time are available to the user. Data inquiry can be performed by a purposely designed module that has the same hardware of the WDMM but a different user interface or by a PDA (Personal Digital Assistant) or a traditional personal computer thanks to a USB connection. Simple supervisory software has been realized under the LabVIEW graphical programming environment. Copyright © 2007 IFSA.

Research paper thumbnail of Performance Assessment of Chirp-Based Time Dissemination and Data Communications in Inductively Coupled Links

IEEE Transactions on Instrumentation and Measurement, 2017

Advantages of inductively coupled links for shortrange communications are well known. Recently, t... more Advantages of inductively coupled links for shortrange 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 proofof-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.

Research paper thumbnail of New Simulation Models to Evaluate Performance of PROFINET IO Class 1 Systems

2007 5th IEEE International Conference on Industrial Informatics, 2007

This paper deals with a simplified method to estimate timing performance of real-time automation ... more This paper deals with a simplified method to estimate timing performance of real-time automation systems based on PROFINET IO fieldbus. Simulations can be an affordable solution to evaluate performance of real-time networks before their physical implementation. In this work, two complete models, one for generic PROFINET IO-controllers and one for generic IO-devices, are presented and their configuration, parameters and attributes

Research paper thumbnail of Improving syntonization of synchronous ethernet nodes using multiple paths

The joint use of clock synchronization and syntonization can provide extremely high accuracy in i... more The joint use of clock synchronization and syntonization can provide extremely high accuracy in industrial and telecom applications. However, in typical implementations of Synchronous Ethernet , only one frequency source at a time is selected for node syntonization (even in the presence of redundant networks with multiple paths), thus losing useful information. In this paper, an algorithm able to synthesize a frequency reference from the fusion of multiple signals over different network paths is presented and validated through simulations. The results confirm that the proposed algorithm is able to improve both frequency stability and robustness of the generated reference signal.

Research paper thumbnail of Leveraging Digital Twin for Sustainability Assessment of an Educational Building

Sustainability, 2021

The EU Green Deal, beginning in 2019, promoted a roadmap for operating the transition to a sustai... more The EU Green Deal, beginning in 2019, promoted a roadmap for operating the transition to a sustainable EU economy by turning climate issues and environmental challenges into opportunities in all policy areas and making the transition fair and inclusive for all. Focusing on the built environment, the voluntary adoption of rating systems for sustainability assessment is growing, with an increasing market value, and is perceived as a social responsibility both by public administration and by private companies. This paper proposes a framework for shifting from a static sustainability assessment to a digital twin (DT)-based and Internet of Things (IoT)-enabled dynamic approach. This new approach allows for a real-time evaluation and control of a wide range of sustainability criteria with a user-centered point of view. A pilot building, namely, the eLUX lab cognitive building in the University of Brescia, was used to test the framework with some sample applications. The educational buildi...

Research paper thumbnail of On the Performance of Cloud Services and Databases for Industrial IoT Scalable Applications

Electronics, 2020

In the Industry 4.0 the communication infrastructure is derived from the Internet of Things (IoT)... more In the Industry 4.0 the communication infrastructure is derived from the Internet of Things (IoT), and it is called Industrial IoT or IIoT. Smart objects deployed on the field collect a large amount of data which is stored and processed in the Cloud to create innovative services. However, differently from most of the consumer applications, the industrial scenario is generally constrained by time-related requirements and its needs for real-time behavior (i.e., bounded and possibly short delays). Unfortunately, timeliness is generally ignored by traditional service provider, and the Cloud is treated as a black box. For instance, Cloud databases (generally seen as “Database as a service”—DBaaS) have unknown or hard-to-compare impact on applications. The novelty of this work is to provide an experimental measurement methodology based on an abstract view of IIoT applications, in order to define some easy-to-evaluate metrics focused on DBaaS latency (no matter the actual implementation de...

Research paper thumbnail of Evaluation of the Use of Class B LoRaWAN for the Coordination of Distributed Interface Protection Systems in Smart Grids

Journal of Sensor and Actuator Networks, 2020

The adoption of the distributed generation paradigm is introducing several changes in the design ... more The adoption of the distributed generation paradigm is introducing several changes in the design and operation of modern distribution networks. Modern grid codes are becoming more and more complex, and the adoption of smart protection systems is becoming mandatory. However, the adoption of newer and smarter units is only half of the story. Proper communication networks must be provided as well, and the overall costs may become critical. In this work, the adoption of the Long-Range Wide Area Network (LoRaWAN) technology is suggested as a viable approach to implement the coordination of Interface Protection Systems. A proper communication architecture based on the LoRaWAN Class B technology was proposed and evaluated in order to assess its feasibility for the considered application. A scalability analysis was carried out, by computing the number of devices that can be handled by a single LoRaWAN Gateway (GW) and the maximum expected time of response between a triggering event and the ...

Research paper thumbnail of A LoRaWAN range extender for Industrial IoT

IEEE Transactions on Industrial Informatics, 2019

The LoRaWAN technology, an example of low power wide area network, is considered a possible IoT-d... more The LoRaWAN technology, an example of low power wide area network, is considered a possible IoT-derived solution for realizing private cellular (single-hop) communications in the industrial domain. However, despite LoRaWAN promises long range and dense environments with many obstacles (as the industrial ones), it may suffer from coverage issue. Additionally, the inverse relationship between data rates and range may be unacceptable for many industrial applications. In this article, an innovative LoRaWAN range extender (based on an enhanced LoRaWAN node) is described, and its integration in the infrastructure of industrial Internet of Things (IIoT)-enabled industrial wireless networks is presented. A frame relay strategy is suggested, thus avoiding to tradeoff the highest data rates against an increased sensitivity. The feasibility of the solution is formally verified and the features of the realized proof-of-concept prototype, based on commercially available hardware, are discussed. The experimental results, obtained with a purposely designed test bench, show the effectiveness of the proposed approach. In particular, the range extender is transparent for legacy LoRaWAN networks as confirmed by correct relaying of uplink and downlink for different types of LoRaWAN message.

Research paper thumbnail of Assessment of Electric Vehicle Charging Costs in Presence of Distributed Photovoltaic Generation and Variable Electricity Tariffs

Energies, 2019

In this paper a general model for the estimation of the uncoordinated charging costs of Electric ... more In this paper a general model for the estimation of the uncoordinated charging costs of Electric Vehicles (EVs) in the presence of distributed and intermittent generation, and variable electricity tariffs is presented. The proposed method aims at estimating the monthly average cost of uncoordinated charging of a single EV depending on the hour at which the EV is plugged into the EV Supply Equipment (EVSE). The feasibility and relevance of the proposed model is verified by applying the considered cost estimation method to a suitable use case. A single EV charging service offered at a public building equipped with a Photovoltaic (PV) system has been considered as reference case. The proposed model has been applied to the PV production and loads consumption data collected during one year, and the results of the study compared with the Time-Of-Use (TOU) electricity tariff. The application of the proposed model identified noticeable deviations among the computed EV charging costs and the...

Research paper thumbnail of Assessment of Time Performance of Lightweight Virtualization for Edge Computing Applications

Research paper thumbnail of A proof of concept application of sensing technologies for managing proximity hazards on construction sites

Proceedings of the 38th International Symposium on Automation and Robotics in Construction (ISARC), 2021

The proceedings series is Scopus indexed.

Research paper thumbnail of A standard CMOS bridge-based analog interface for differential capacitive sensors

2017 13th Conference on Ph.D. Research in Microelectronics and Electronics (PRIME), 2017

This work describes an analog electronic interface, based on a modified De Sauty AC bridge, perfo... more 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).

Research paper thumbnail of On the use of LPWAN for EVehicle to grid communication

2017 AEIT International Annual Conference, 2017

The expected diffusion of EVehicles (EVs) to limit the impact of fossil fuel on mobility is going... more 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.

Research paper thumbnail of Enhanced flexible LoRaWAN node for industrial IoT

2018 14th IEEE International Workshop on Factory Communication Systems (WFCS), 2018

The Industrial Internet of Things (IIoT) is introducing the IoT approach in the industrial automa... more The Industrial Internet of Things (IIoT) is introducing the IoT approach in the industrial automation world, paving the way to innovative services for improving efficiency, reliability and availability of industrial processes and products. The IIoT takes advantage of the collection of large amount of data by means of (wireless) links connecting smart sensors attached to the system of interest. Low Power Wide Area Networks emerged as a viable solution for implementing private cellular like communications. In this paper, the LoRaWAN technology is addressed, thanks to the wide acceptance it received in both industrial and academic worlds. In particular, an enhanced node is proposed as a building block of IIoT-enabled industrial wireless networks. It offers new features: it behaves as a regular node; it can act as a gateway toward legacy/different (wired) networks; and it can extend LoRaWAN coverage acting as a range extender (i.e. a single hop forwarder). After a brief overview of LoRa and LoRaWAN, the paper deals with the features of the realized node, exploiting commercially available hardware. The experimental results show the feasibility of the proposed approach. In particular, the range extender capability of transmitting replicas of an incoming messages is tested for different transmission delays.

Research paper thumbnail of Improving Redundancy in LoRaWAN for Mixed-Criticality Scenarios

IEEE Systems Journal, 2021

Most Internet of Things applications rely on wireless communication, which ensures flexibility an... more Most Internet of Things applications rely on wireless communication, which ensures flexibility and scalability. However, an increasing number of these applications have real-time constraints and require mixed-criticality. Indeed, the complexity of distributed systems necessarily calls for data exchanges with different priorities and different failure handling. The design of a reliable protocol supporting different traffic priorities must take into account external interferences that can inevitably affect radio links. This article focuses on LoRaWAN, the currently most famous example of low power wide area network technology. In particular, redundant transmissions offered by the proposed LoRa-REP strategy enhance the communication resilience of sporadic critical message transaction (consisting of message uplink and acknowledgment downlink). The implementation by means of “virtual nodes” assures compatibility with legacy deployments (preserving investments) and offers easy scalability. Experimental results obtained with purposely designed test bench confirm the advantages of the proposed solution in a real-world scenario. Notably, the failure probability of a critical transaction drops from 78% of single spreading factor scenario to less than 2.5% with the proposed LoRa-REP.

Research paper thumbnail of A CMOS full-range linear integrated interface for differential capacitive sensor readout

Sensors and Actuators A: Physical, 2018

This manuscript presents the development of an integrated analog interface able to convert differ... more This manuscript presents the development of an integrated analog interface able to convert differential capacitive sensors variations into a DC voltage. The presented circuit exploits the architecture developed in previous works of the same authors, based on autobalancing bridge techniques, further improving its performances through the linearization of the input/output characteristic and the achievement of the full-range sensor variations capability. The interface takes advantage of Low Voltage and Low Power integrated circuit design techniques, optimizing performances for flux and force sensor. Simulated results with the AMS 0.35um standard CMOS technology have shown a very good agreement with the theoretical model developed, obtaining an error lower than 2.5% and a total power consumption of 5mW. Moreover, waiting for the chip production, a discrete element board has been also implemented and tested. Preliminary measurements on the test board have shown satisfactory input/output linearity characteristics with overall reduced percentage error (lower than 1.5%) in the measurand estimation.

Research paper thumbnail of Integrating remote sensors in a smartphone: The project "sensors for ANDROID in embedded systems

2016 IEEE Sensors Applications Symposium (SAS), 2016

Nowadays, smartphones integrate high quality sensors and communication systems, easily managed by... more Nowadays, smartphones integrate high quality sensors and communication systems, easily managed by simple APPs under Android. On the contrary, managing remote sensors requires a big effort in programming, both on the sensor and on the Smartphone side. In this work, a solution for filling this gap is proposed, providing the instruments to easily handle remote sensors, exactly as if they were embedded in Android environment. The work exploits the Bluetooth 4.0-4.1 technology and realizes a library for remote smart sensors managing. Two new tools are described: a framework, which allows the Android developers to handle the remote resources (i.e. sensors and actuators) with the same approach to the embedded resources; a tool for programming and addressing the resources of the remote sensors. The proposed architecture is experimentally evaluated in a possible scenario of home automation.

Research paper thumbnail of On the Use of Magnetically Coupled Resonators for Chirp-Based Timestamping

IEEE Transactions on Instrumentation and Measurement, 2015

The knowledge of the time value at which an event of interest occurred is the typical feature nee... more The knowledge of the time value at which an event of interest occurred is the typical feature needed to perform many kinds of postprocessing in distributed sensor networks. Consequently, network-based distributed systems must support time dissemination in order to ensure that relative clock errors among nodes remain below a certain threshold. Despite many protocols being well established for wired connections, the wireless sensor network paradigm required a new approach to address adverse characteristics of the wireless medium. In this paper, the adoption of low-frequency signaling is proposed for overcoming some issues of radio frequency transmissions when used for timestamping events. The proposed approach is characterized using numerical simulations and an experimental prototype, based on inductive coupling of tuned resonators. Experimental tests confirm the effectiveness and feasibility of this approach that achieves microsecond-order time recovery performance in practical system configurations.

Research paper thumbnail of First Conference on

Research paper thumbnail of An autonomous sensor with energy harvesting capability for airflow speed measurements

2010 IEEE International Instrumentation and Measurement Technology Conference, I2MTC 2010 - Proceedings, 2010

In several environments modest ambient airflows are present, for example, in airconditioning duct... more In several environments modest ambient airflows are present, for example, in airconditioning ducts, in outdoor environment, or in moving vehicles. Furthermore, an airflow speed measurement is an important indicator, for the energy efficiency in the regulation of the conditioning implants. An autonomous sensor placed in a duct and powered by an electromechanical generator scavenging energy from the airflow has been designed and tested. The airflow speed is measured trough the rotor frequency of the electromechanical generator. When the external readout unit is active the electromagnetic field is used to power the autonomous sensor system and transmit the data. A set of tests on three airflow harvesters using resistive loads was conducted to demonstrate their energy conversion potentials. An experimental system has been designed and realized demonstrating that the airflow harvester can power the autonomous sensor permitting airflow speed measurements.

Research paper thumbnail of Simple and Low-Cost Wireless Distributed Measurement System

This paper describes the design and realization of a simple and low-cost system for distributed m... more This paper describes the design and realization of a simple and low-cost system for distributed measurements. Traditional handheld digital multimeters have been equipped with a radio- frequency interface in order to implement what the authors call WDMM, the basic block of a wireless multi-probe data logger. New functionalities require very few components and result in a cost increase of less than 10$. In addition, also maintenance has been facilitated since tracking data such as working state or last calibration time are available to the user. Data inquiry can be performed by a purposely designed module that has the same hardware of the WDMM but a different user interface or by a PDA (Personal Digital Assistant) or a traditional personal computer thanks to a USB connection. Simple supervisory software has been realized under the LabVIEW graphical programming environment. Copyright © 2007 IFSA.

Research paper thumbnail of Performance Assessment of Chirp-Based Time Dissemination and Data Communications in Inductively Coupled Links

IEEE Transactions on Instrumentation and Measurement, 2017

Advantages of inductively coupled links for shortrange communications are well known. Recently, t... more Advantages of inductively coupled links for shortrange 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 proofof-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.

Research paper thumbnail of New Simulation Models to Evaluate Performance of PROFINET IO Class 1 Systems

2007 5th IEEE International Conference on Industrial Informatics, 2007

This paper deals with a simplified method to estimate timing performance of real-time automation ... more This paper deals with a simplified method to estimate timing performance of real-time automation systems based on PROFINET IO fieldbus. Simulations can be an affordable solution to evaluate performance of real-time networks before their physical implementation. In this work, two complete models, one for generic PROFINET IO-controllers and one for generic IO-devices, are presented and their configuration, parameters and attributes

Research paper thumbnail of Improving syntonization of synchronous ethernet nodes using multiple paths

The joint use of clock synchronization and syntonization can provide extremely high accuracy in i... more The joint use of clock synchronization and syntonization can provide extremely high accuracy in industrial and telecom applications. However, in typical implementations of Synchronous Ethernet , only one frequency source at a time is selected for node syntonization (even in the presence of redundant networks with multiple paths), thus losing useful information. In this paper, an algorithm able to synthesize a frequency reference from the fusion of multiple signals over different network paths is presented and validated through simulations. The results confirm that the proposed algorithm is able to improve both frequency stability and robustness of the generated reference signal.

Research paper thumbnail of Leveraging Digital Twin for Sustainability Assessment of an Educational Building

Sustainability, 2021

The EU Green Deal, beginning in 2019, promoted a roadmap for operating the transition to a sustai... more The EU Green Deal, beginning in 2019, promoted a roadmap for operating the transition to a sustainable EU economy by turning climate issues and environmental challenges into opportunities in all policy areas and making the transition fair and inclusive for all. Focusing on the built environment, the voluntary adoption of rating systems for sustainability assessment is growing, with an increasing market value, and is perceived as a social responsibility both by public administration and by private companies. This paper proposes a framework for shifting from a static sustainability assessment to a digital twin (DT)-based and Internet of Things (IoT)-enabled dynamic approach. This new approach allows for a real-time evaluation and control of a wide range of sustainability criteria with a user-centered point of view. A pilot building, namely, the eLUX lab cognitive building in the University of Brescia, was used to test the framework with some sample applications. The educational buildi...

Research paper thumbnail of On the Performance of Cloud Services and Databases for Industrial IoT Scalable Applications

Electronics, 2020

In the Industry 4.0 the communication infrastructure is derived from the Internet of Things (IoT)... more In the Industry 4.0 the communication infrastructure is derived from the Internet of Things (IoT), and it is called Industrial IoT or IIoT. Smart objects deployed on the field collect a large amount of data which is stored and processed in the Cloud to create innovative services. However, differently from most of the consumer applications, the industrial scenario is generally constrained by time-related requirements and its needs for real-time behavior (i.e., bounded and possibly short delays). Unfortunately, timeliness is generally ignored by traditional service provider, and the Cloud is treated as a black box. For instance, Cloud databases (generally seen as “Database as a service”—DBaaS) have unknown or hard-to-compare impact on applications. The novelty of this work is to provide an experimental measurement methodology based on an abstract view of IIoT applications, in order to define some easy-to-evaluate metrics focused on DBaaS latency (no matter the actual implementation de...

Research paper thumbnail of Evaluation of the Use of Class B LoRaWAN for the Coordination of Distributed Interface Protection Systems in Smart Grids

Journal of Sensor and Actuator Networks, 2020

The adoption of the distributed generation paradigm is introducing several changes in the design ... more The adoption of the distributed generation paradigm is introducing several changes in the design and operation of modern distribution networks. Modern grid codes are becoming more and more complex, and the adoption of smart protection systems is becoming mandatory. However, the adoption of newer and smarter units is only half of the story. Proper communication networks must be provided as well, and the overall costs may become critical. In this work, the adoption of the Long-Range Wide Area Network (LoRaWAN) technology is suggested as a viable approach to implement the coordination of Interface Protection Systems. A proper communication architecture based on the LoRaWAN Class B technology was proposed and evaluated in order to assess its feasibility for the considered application. A scalability analysis was carried out, by computing the number of devices that can be handled by a single LoRaWAN Gateway (GW) and the maximum expected time of response between a triggering event and the ...

Research paper thumbnail of A LoRaWAN range extender for Industrial IoT

IEEE Transactions on Industrial Informatics, 2019

The LoRaWAN technology, an example of low power wide area network, is considered a possible IoT-d... more The LoRaWAN technology, an example of low power wide area network, is considered a possible IoT-derived solution for realizing private cellular (single-hop) communications in the industrial domain. However, despite LoRaWAN promises long range and dense environments with many obstacles (as the industrial ones), it may suffer from coverage issue. Additionally, the inverse relationship between data rates and range may be unacceptable for many industrial applications. In this article, an innovative LoRaWAN range extender (based on an enhanced LoRaWAN node) is described, and its integration in the infrastructure of industrial Internet of Things (IIoT)-enabled industrial wireless networks is presented. A frame relay strategy is suggested, thus avoiding to tradeoff the highest data rates against an increased sensitivity. The feasibility of the solution is formally verified and the features of the realized proof-of-concept prototype, based on commercially available hardware, are discussed. The experimental results, obtained with a purposely designed test bench, show the effectiveness of the proposed approach. In particular, the range extender is transparent for legacy LoRaWAN networks as confirmed by correct relaying of uplink and downlink for different types of LoRaWAN message.

Research paper thumbnail of Assessment of Electric Vehicle Charging Costs in Presence of Distributed Photovoltaic Generation and Variable Electricity Tariffs

Energies, 2019

In this paper a general model for the estimation of the uncoordinated charging costs of Electric ... more In this paper a general model for the estimation of the uncoordinated charging costs of Electric Vehicles (EVs) in the presence of distributed and intermittent generation, and variable electricity tariffs is presented. The proposed method aims at estimating the monthly average cost of uncoordinated charging of a single EV depending on the hour at which the EV is plugged into the EV Supply Equipment (EVSE). The feasibility and relevance of the proposed model is verified by applying the considered cost estimation method to a suitable use case. A single EV charging service offered at a public building equipped with a Photovoltaic (PV) system has been considered as reference case. The proposed model has been applied to the PV production and loads consumption data collected during one year, and the results of the study compared with the Time-Of-Use (TOU) electricity tariff. The application of the proposed model identified noticeable deviations among the computed EV charging costs and the...