R. Ramilli, F. Santoni, A. De Angelis, M. Crescentini, P. Carbone, P. A. Traverso; Binary Sequences for Online Electrochemical Impedance Spectroscopy of Battery Cells

Published in: IEEE Transactions on Instrumentation and Measurement ( Volume: 71)
Date of Publication: 16 August 2022
Publisher: IEEE

Abstract: Online diagnostic of lithium-ion battery (LIB) cells may have significant impact on chemical energy storage systems. Electrochemical impedance spectroscopy (EIS) is widely used for the characterization of LIBs and could be the most appropriate technique for online diagnostic, but its response time should be shortened. This work investigates the usage of multisine excitation to shorten the measurement time and simplify the hardware implementation for EIS of battery cells. Two types of multisine binary sequences are considered: sigma–delta modulated multisine sequences (SDMSs) and maximum length binary sequences (MLBSs). Their applicability to online and in situ EIS monitoring is evaluated by designing a measurement architecture also suitable to be implemented in a system-on-chip. The calibrated measurement system is compared with a benchtop reference instrument, reporting an RMSE deviation smaller than 5% in the frequency range of interest 1–200 Hz. The realized system is then used for online monitoring of the discharge process of a commercial 18650 LIB cell. The two proposed sequences are compared in terms of accuracy using a digital battery emulator circuit. Both the sequences demonstrated to be suitable for fast measurement and simple hardware integration, enabling online in situ EIS monitoring at cell level.

Keywords: Batteries, Battery charge measurement, Impedance, Monitoring, Time measurement, Frequency measurement, Sigma-delta modulation

Gemma Giliberti, Francesco Di Giacomo, Federica Cappelluti; Three Terminal Perovskite/Silicon Solar Cell with Bipolar Transistor Architecture

Published in: Energies, Vol.15, Issue 21, 10.3390/en15218146 
Date Added to IEEE Xplore: 1 November 2022
Publisher: IEEE

Abstract: Solar photovoltaic energy is the most prominent candidate to speed up the transition from the existing non-renewable energy system to a more efficient and environmentally friendly one. Currently, silicon cells dominate the photovoltaic market owing to their cost-effectiveness and high efficiency, nowadays approaching the theoretical limit. Higher efficiency can be achieved by tandem devices, where a wide bandgap semiconductor is stacked on top of the silicon cell. Thin-film perovskite technology has emerged as one of the most promising for the development of silicon-based tandems because of the optimal perovskite opto-electronic properties and the fast progress achieved in the last decade. While most of the reported perovskite/silicon tandem devices exploit a two-terminal series connected structure, three-terminal solutions have recently drawn significant attention due to their potential for higher energy yield. In this work, we report for the first time a theoretical study, based on validated optical and electrical simulations, of three-terminal perovskite/silicon solar cells employing a hetero-junction bipolar transistor structure. With respect to other three-terminal tandems proposed so far, the transistor structure can be implemented with rear-contact silicon cells, which are simpler and more common than interdigitated back-contact ones.

Keywords: double junction; perovskite; silicon tandem; three-terminal; HIT solar cell; bipolar junction architecture; physical simulation

Federica Zonzini, Masoud Mohammadgholiha, Luca De Marchi; A Combination of Chirp Spread Spectrum and Frequency Hopping for Guided Waves-based Digital Data Communication with Frequency Steerable Acoustic Transducers

Published in: 2022 IEEE International Ultrasonics Symposium (IUS)
Date Added to IEEE Xplore: 1 December 2022
DOI: 10.1109/IUS54386.2022.9958662
Publisher: IEEE

Abstract: To facilitate Guided Waves (GWs) communication in terms of hardware simplification and cost reductions, shaped transducers with inherent directional properties can be used. A promising example of such devices is provided by Frequency Steerable Acoustic Transducers (FSATs), where the propagation direction of waves is controlled by the frequency content of the transmitted/acquired signals, thanks to the spatial filtering effect. These peculiar characteristics make the FSAT devices particularly suited for implementation of frequency-based modulation protocols, in which the signal content assigned to each user is uniquely encoded by a corresponding carrier tone. In this work, the special directivity of FSATs is paired with a novel encoding strategy, which is based on a combination of Chirp Spread Spectrum (CSS) and Frequency Hopping (FH) multiplexing, similar to the LoRaWan solution adopted in radio-frequency environments. The devised strategy is aimed at suppressing the inherent destructive interference due to GWs dispersion and multi-path fading.

Keywords: Acoustic Data Communications, Chirp Spread Spectrum, Frequency Hopping, Frequency Steerable Acoustic Transducers

Federica Zonzini, Masoud Mohammadgholiha, Luca De Marchi; Enabling Spatial Multiplexing in Guided Waves-based Communication: the case of Quadrature Amplitude Modulation realized via Discrete Frequency Steerable Acoustic Transducers

Published in: 2022 IEEE International Ultrasonics Symposium (IUS)
Date Added to IEEE Xplore: 1 December 2022
DOI: 10.1109/IUS54386.2022.9958829
Publisher: IEEE

Abstract: Guided Waves (GWs) communication using conventional transducers, e.g., PZT, encounters quite a few problems, such as complex hardware systems and waves multipath interference. To overcome such drawbacks, Frequency Steerable Acoustic Transducers (FSATs) which benefit from inherent directional capabilities can be fruitfully adopted to implement a spatial multiplexing strategy. The FSATs work on the frequency-dependent spatial filtering effect to generate/receive waves, resulting in a direct relationship between the direction of propagation and the frequency content of the transmitted/received signals. Thanks to this unique frequency-steering capability, FSATs are best suited to implement frequency-driven modulation protocols, such as the ones typically exploited for GWs-based data communication. Among these, the Quadrature Amplitude Modulation (QAM) scheme is advantageous in terms of noise immunity. Thus, the objective of this work is to combine QAM with the built-in spatial multiplexing capabilities of FSATs to realize, in hardware, frequency directivity, like the solutions that are currently being investigated in 5G communications.

Keywords: Acoustic Data Communications, Frequency Steerable Acoustic Transducers, Quadrature Amplitude Modulation

Autonomous Driving Systems Demo Video

This is a short demonstration video about the simulator developed for Energy ECS project by Lapin AMK (Lapland university of applied sciences). The simulator can be used to develop, train and validate autonomous driving systems.

Click the picture to see the video

Henrik Staaf, Simon Matsson, Sobhan Sepheri, Elof Köhler, Kaies Daoud, Fredrik Ahrentorp, Christian Jonasson, Peter Folkow, Leena Ryynänen, Mika Penttila, Cristina Rusu; Simulated and measured piezoelectric energy harvesting of dynamic load in tires’ submitted to Heliyon Energy

Published in: SSRN 4435728
Posted Date: 7 June 2023
Publisher: SSRN

Abstract: Sensors mounted in tires require a continuous power supply, currently from batteries. Piezoelectric energy harvesting is a promising technology to harvest energy from tire movement and deformation. This study presents a new simulation method to model simultaneous the combination of tire deformation and piezoelectric harvester with dynamic bending zone. The approach combines numerical simulations in COMSOL Multiphysics with real-life measurements of electrical output of a piezoelectric energy harvester mounted on a tire. In the simulation, angular and initial velocities were used for rolling motion, angled polarization was introduced in the model for the piezoelectric material to generate correct voltage from tire deformation. Experimental measurements conducted at Nokian Tyres and RISE show good agreement with dynamic simulation. The study also shows the importance of optimizing the harvester’s geometry for maximum electrical output which can power some tire sensors.

Keywords: Zero energy devices, Energy harvesting, Piezoelectricity, PVDF

Cristina Rusu, Mike Hayes; Presentation: Major Research Collaborations Driving Energy Harvesting TRL progression and Power IoT Ecosystem

Presentation Link: RISE Presentation, Sensor Converge June 2023
Conference: Sensor Converge, 20 – 22 June 2023
Session Title: Extending Battery Life to Empower the IoT/IIoT

In the ‘Sensors Converge’ event held from June 20-22, 2023, Energy ECS ‘s Swedish partner, RISE, presented first results from their collaborative research in the session ‘Extending Battery Life to Empower the IoT/IIoT’.

One of the discussed Use Cases from Energy ECS project under discussion was the ‘UC2A Smart Containers’. The UC has successfully extended battery life for over a decade by using photovoltaic energy harvesting. This technology optimizes consumption and enables fully digitized supply chains, marking a significant leap towards sustainable and efficient logistics. The second Use Case, ‘UC5 Self-powered Tyres’, addresses the intricate challenges related to harvesting energy from tire movement and development of the energy harvesting system for harsh environment. This research is set to revolutionize the understanding and application of renewable energy harvesting for tire technology and in the industry.

The presentation at ‘Sensors Converge’ stimulated engaging discussions on the crucial role of Energy ECS’s technology in e-mobility and IoT power solutions. The recognition of the technological advancements made by Energy ECS and RISE underlines the importance of their research in the field of energy efficiency.

N. Lowenthal, G. P. Gibiino, C. Tamburini, M. Mengozzi, A. Romani, P. A. Traverso; Automated Measurement Set-Up for the Electro-Mechanical Characterization of Piezoelectric Harvesters

Published in: 2023 IEEE International Workshop on Metrology for Automotive (MetroAutomotive)
Date of Conference: 28 – 30 June 2023
Publisher: IEEE

Abstract: This paper presents an automated measurement setup for the electro-mechanical characterization of piezoelectric energy harvesters in cantilever configuration. The setup provides a mechanical stimulus to the harvester and concurrently acquires mechanical and electrical quantities to characterize the electro-mechanical properties of the device under test in open-circuit conditions. The setup, composed by an electrodynamic shaker, a waveform analyzer, and two laser-based positioning sensors, is fully controlled via MATLAB. The use of two laser heads allows to measure the movement of the base, so to automatically consider artefacts due to the non-ideal response of the electrodynamic shaker. The proposed measurement system is compatible with any generic piezoelectric-cantilever harvesters, and it can be exploited for advanced modelling techniques that requires extensive experimental data. The proposed measurement setup was validated through the characterization of a commercial Piezo Protection Advantage (PPA) transducer up to 300 Hz.

Keywords: Vibrations, Electrodynamics, Transducers, Phase measurement, Sensor phenomena and characterization, Metrology, Frequency measurement

N. Lowenthal, R. Ramilli, M. Crescentini, P. A. Traverso; Development of a numerical framework for the analysis of a multi-tone EIS measurement system

Published in: 2023 IEEE International Workshop on Metrology for Automotive (MetroAutomotive)
Date of Conference: 28 – 30 June 2023
Publisher: IEEE

Abstract: This paper describes an integrated co-simulation framework of circuital/behavioural/algorithmic type devoted to the design, simulation, and support to validation of a system of measurement based on electrochemical impedance spectroscopy (EIS) for lithium-ion battery cells. The simulation framework comprises two main parts: a circuital simulator and a numerical environment. It allows the study of a generic system: in particular, it has been applied to analyze an EIS system as a whole without neglecting the effects of the hardware nonidealities on the software algorithm (through a direct connection between the circuital simulator and the numerical environment). A model is implemented inside the circuital simulator, replicating as accurately as possible an existing laboratory prototype devoted to EIS measurements. After the simulation of the prototype, the numerical environment executes an algorithmic elaboration to estimate impedance values for a lithium-ion battery. Throughout several simulations, it is possible to check the non-idealities of the prototype. The simulation framework identified and corrected a malfunction of the prototype available in the laboratory and thus permitted the implementation of a circuit with improved performance.

Keywords: Lithium-iron batteries, Impedance measurement, Software algorithms, Prototypes, Battery charge measurement, Software, Mathematical models

M. Mohammadgholiha, F. Zonzini, J. Moll, L. De Marchi; Directional Multi-Frequency Guided Waves Communications Using Discrete Frequency-Steerable Acoustic Transducers

Published in: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control ( Early Access )
Date of Publication: 14 August 2023
DOI: 10.1109/TUFFC.2023.3305032
Publisher: IEEE

Abstract: A novel directional transducer based on Guided Waves (GW) is introduced in this paper, designed for use in structural health monitoring (SHM) and acoustic data communication applications, i.e., systems in which the elastic medium serves as a transmission channel and information is conveyed through the medium via elastic waves. Such systems can overcome difficulties associated with traditional communication methods like wire-based or radio frequency (RF), which can be complex and have limitations in harsh environments or hard-to-reach places. However, the development of these techniques is hampered by GW dispersive and multi-modal propagation and by multi-path interference. The shortcomings can be effectively addressed by employing Frequency Steerable Acoustic Transducers (FSATs), which leverage their inherent directional capabilities. This can be achieved through the exploitation of a frequency-dependent spatial filtering effect, yielding to a direct correlation between the frequency content of the transmitted or received signals and the direction of propagation. The proposed transducer is designed to actuate or sense the A0 Lamb wave propagating in three orientations using varying frequencies, and has three channels with distinct frequencies for each direction, ranging from 50 kHz to 450 kHz. The transducer performance was verified through Finite Element (FE) simulations, accompanied by experimental testing using a Scanning Laser Doppler Vibrometer (SLDV). The unique frequency-steering capability of FSATs is combined with the On-Off Keying (OOK) modulation scheme to achieve frequency directivity in hardware, similar to ongoing research in 5G communications. The MIMO capabilities of the transducer were finally tested over a thin aluminum plate, showing excellent agreement with the FE simulation results.

Keywords: Transducers, Acoustics, Dispersion, Data communication, Shape, Sensors, Frequency modulation

Aldo Romani, Marco Crescentini, Christina Rusu, Henrik Staaf, Marco Ambrosio, Marcello Chiaberge, Anna Piacibello, Marco Pirola, Gemma Giliberti, Federica Cappelluti, Giovanni Ghione, Michael Hayes, Eoin Ahern, Prateek Asthana, Gerd vom Bögel, Marco Galiazzo, Leena Ryynänen, Mika Penttilä, Heini Siekkinen, Stefano Saggini, Federico Iob, Giulia Segatti, Rahul Tomar, Mohith Bhargav Sunkara, Rucha Mangesh Kathe, Paolo Mezzanotte, Iftikhar Ahmad, Ksenia Avetisova; The ENERGY ECS Project: Smart and Secure Energy Solutions for Future Mobility

Published in: AEIT International Conference on Electrical and Electronic Technologies for Automotive, AEIT AUTOMOTIVE 2023 
Date of Publication: 23 August 2023
DOI: 10.3030/101007247
Publisher: IEEE

Abstract: Electric and smart mobility are key enablers for their green energy transition. However, the electrification of vehicles poses several challenges, from the development of power components to the organization of the electric grid system. Moreover, it is expected that the smartification of mobility via sensors and novel transport paradigms will play an essential role in the reduction of the consumed energy. In response to these challenges and expectations, the ENERGY ECS project is pursuing smart and secure energy solutions for the mobility of the future, by developing power components, battery charging electronics, and self-powered sensors for condition monitoring, along with advanced techniques for grid management, applications of artificial intelligence, machine learning and immersing technologies. This paper presents the project’s objectives and reports intermediate results from the perspective of the targeted use cases.

Keywords: Energy, Mobility, Electronics, Components, Systems, Sensors, Batteries, Drones, Grids

Gerd vom Bögel, Felix Essingholt, Bernhard Bennertz, Thorben Grenter; Digitization of the Distribution Grid to Support e-Mobility Charging Infrastructure

Published in: IEEE International Workshop on Metrology for Automotive, MetroAutomotive 2023. Proceedings
Date of Publication: 23 August 2023
DOI: 10.1109/MetroAutomotive57488.2023
Publisher: IEEE

Abstract: The article addresses a subproject of the Energy ECS project, in which the development and realization of suitable components for condition monitoring of electrical distribution grids is carried out. By means of suitable sensor systems, communication and IT infrastructure components, relevant information on network infrastructure elements at neuralgic points is collected, aggregated and communicated. This information can be used directly for a highly dynamic grid-serving control of grid components to ensure a robust and efficient use of the distribution grid. The project makes a direct contribution to the digitization of distribution grids and thus contributes to the successful integration of decentralized generators and electromobility. The main objective of the subproject is the development and realization of energy-autonomous sensor systems for recording the status of relevant components of a low-voltage distribution network. The work to be carried out includes sensor principles as well as the field of energy harvesting or the field of sensor signal processing.

Keywords: Smart grid monitoring, Self-sufficient sensor, LPWAN, Controlled charging infrastructure, Charging infrastructure

Stefano Taccetti, Lorenzo Mistral Peppi, Federica Zonzini, Masoud Mohammadgholiha, Matteo Zauli, Luca De Marchi; Design of a Novel Pulser for Frequency Selective-based Power and Data Transmission

Published in: 2023 IEEE International Workshop on Metrology for Automotive (MetroAutomotive)
Date of Publication: 23 August 2023
DOI: 10.1109/MetroAutomotive57488.2023.10219099
Publisher: IEEE

Abstract: This paper proposes an ultrasonic system based on an innovative piezoelectric device, the Frequency Steerable Acoustic Transducer (FSAT). The FSAT’s high directivity can be exploited for structural inspection, and through-metal data communication and wireless power transfer. These three functions are fundamental in an autonomous sensor system developed for condition monitoring, which is a central requirement in many sectors, such as automotive. A novel pulser, made up of a signal generator and a power amplifier, has been designed and simulated, for effectively driving the FSAT transducer. Experimental results showed that the designed power amplifier is able to reach a gain of 17.80 dB driving the piezoelectric transducer with a maximum peak-to-peak voltage of 24 V and that its bandwidth is [3.1-964] kHz. Experiments have been carried out showing a great improvement in trasmission using the designed amplifier.

Keywords: Guided waves pulser, Structural inspection

Cinzia Tamburini, Matteo Pizzotti, Leena Ryynanen, Mika Penttila, Aldo Romani; Wireless telemetry for characterization of piezoelectric energy harvesters in tires

Published in: 2023 IEEE SENSORS
Date Added to IEEE Xplore: 28 November 2023
DOI: 10.1109/SENSORS56945.2023.10325316
Publisher: IEEE

Abstract: In order to design electronic systems and circuits powered by mechanical energy harvesting in novel applications, it is essential to obtain information about electrical quantities related to the transducer like voltages, currents, and power in realistic operating conditions. However, in some cases, e.g. in tires, transducers and circuits are not accessible, and it is difficult to predict theoretically or numerically the exact values of the above mentioned quantities. To overcome this limitation, this paper presents the design of a wireless telemetry circuit capable of measuring and acquiring open-circuit voltage, short-circuit currents, and static power transfer characteristics from piezoelectric transducers. The circuit was tested in a commercial tire on a drum test machine at different speeds and axial loads. The characterization under these conditions of a commercial piezoelectric harvester suitable for use in tires is reported.

Keywords: telemetry, piezoelectric transducers, energy harvesting, tires