Publicaciones | Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señales

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2025

Jamilis, M.; Castañeda, M.; Battista, H. De

Extremum‐Seeking Control for Methane Production Optimization in Low‐Cost Anaerobic Digesters Artículo de revista

En: Biotech & Bioengineering, 2025, ISSN: 1097-0290.

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Saavedra, M.; Faedo, N.; Inthamoussou, F.; Mosquera, F.; Garelli, F.

Comparative evaluation of data-based estimators for wave-induced force in wave energy converters Artículo de revista

En: J. Ocean Eng. Mar. Energy, 2025, ISSN: 2198-6452.

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@article{Saavedra2025,

title = {Comparative evaluation of data-based estimators for wave-induced force in wave energy converters},

author = {M. Saavedra and N. Faedo and F. Inthamoussou and F. Mosquera and F. Garelli},

doi = {10.1007/s40722-025-00427-4},

issn = {2198-6452},

year  = {2025},

date = {2025-09-01},

urldate = {2025-09-01},

journal = {J. Ocean Eng. Mar. Energy},

publisher = {Springer Science and Business Media LLC},

abstract = {<jats:title>Abstract</jats:title>

          <jats:p>Wave energy conversion technology emerges as a promising approach to renewable energy generation, offering a consistent and predictable power source that complements intermittent renewable energy sources such as solar and wind power. Achieving optimal ocean wave energy absorption requires precise knowledge of the so-called wave excitation force, which is typically estimated through model-based techniques reliant on accurate system descriptions. However, uncertainties inherent to hydrodynamic modelling often limit the reliability of these approaches. To address this challenge, this paper presents a comprehensive evaluation of model-free data-based estimators, for wave excitation torque estimation in Wavestar like wave energy converters (WECs). The study examines various neural network architectures, including static models (feedforward networks) and those incorporating temporal dynamics (recurrent neural networks and long short-term memory networks). The analysis examines the impact of utilising multiple input combinations, ranging from motion variables to configurations enhanced with surrounding wave height measurements from the device’s vicinity. Input selection is guided by correlation analysis and spectral coherence evaluation to ensure physical relevance and practical feasibility. Estimators are trained and tested using experimental data obtained from a comprehensive wave tank campaign emulating diverse sea state conditions. The results demonstrate that architectures incorporating temporal considerations achieve superior performance, particularly under wide-banded sea states. A comparative analysis with a model-based estimator, implemented via a Kalman–Bucy Filter with a harmonic oscillator expansion, highlights the advantages of neural networks, especially under challenging conditions where model-based approaches face significant limitations. These findings underscore the capability of data-based strategies to reduce dependence on potentially complex and uncertain analytical models, offering a promising alternative for improving WEC control systems.</jats:p>},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

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Abstract
Wave energy conversion technology emerges as a promising approach to renewable energy generation, offering a consistent and predictable power source that complements intermittent renewable energy sources such as solar and wind power. Achieving optimal ocean wave energy absorption requires precise knowledge of the so-called wave excitation force, which is typically estimated through model-based techniques reliant on accurate system descriptions. However, uncertainties inherent to hydrodynamic modelling often limit the reliability of these approaches. To address this challenge, this paper presents a comprehensive evaluation of model-free data-based estimators, for wave excitation torque estimation in Wavestar like wave energy converters (WECs). The study examines various neural network architectures, including static models (feedforward networks) and those incorporating temporal dynamics (recurrent neural networks and long short-term memory networks). The analysis examines the impact of utilising multiple input combinations, ranging from motion variables to configurations enhanced with surrounding wave height measurements from the device’s vicinity. Input selection is guided by correlation analysis and spectral coherence evaluation to ensure physical relevance and practical feasibility. Estimators are trained and tested using experimental data obtained from a comprehensive wave tank campaign emulating diverse sea state conditions. The results demonstrate that architectures incorporating temporal considerations achieve superior performance, particularly under wide-banded sea states. A comparative analysis with a model-based estimator, implemented via a Kalman–Bucy Filter with a harmonic oscillator expansion, highlights the advantages of neural networks, especially under challenging conditions where model-based approaches face significant limitations. These findings underscore the capability of data-based strategies to reduce dependence on potentially complex and uncertain analytical models, offering a promising alternative for improving WEC control systems.

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Jurao, F. L. Da Rosa; Fushimi, E.; Garelli, F.

Switched Controllers in Fully Closed Loop Insulin Delivery Systems: Reducing the Trade-Off Between Prandial Control and Safety Artículo de revista

En: Artificial Organs, vol. n/a, no n/a, 2025.

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@article{https://doi.org/10.1111/aor.15064,

title = {Switched Controllers in Fully Closed Loop Insulin Delivery Systems: Reducing the Trade-Off Between Prandial Control and Safety},

author = { F. L. Da Rosa Jurao and E. Fushimi and F. Garelli},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/aor.15064},

doi = {https://doi.org/10.1111/aor.15064},

year  = {2025},

date = {2025-08-02},

urldate = {2025-08-02},

journal = {Artificial Organs},

volume = {n/a},

number = {n/a},

abstract = {ABSTRACT Background One of the main challenges in control algorithm design for full closed-loop automated insulin delivery systems is the trade-off between the effective compensation of meal-related disturbances and ensuring user safety during the postprandial and fasting periods. Methods This paper proposes and evaluates the performance of a switched tuning strategy, a promising but relatively underexplored solution in this domain. This method employs two distinct tunings of a primary control algorithm: an aggressive tuning for meal compensation and a conservative tuning for fasting periods. The analysis considers implementing the switched strategy for three control algorithms: model predictive control and proportional-derivative control, both widely used for glucose regulation, and a linear quadratic Gaussian control, an optimal algorithm previously validated in clinical settings under a switched structure. Additionally, to obtain a more comprehensive understanding of the switched strategy implications, two nonswitched controllers are implemented for each control algorithm: an aggressive and a conservative tuning strategy. Results The switched strategy significantly improves the trade-off between meal compensation and safety, increasing the time within the target range of 70–180 [mg/dL] for all three algorithms. For proportional-derivative control, the time in range increases from 69.1% with the conservative tuning and 83.1% with the aggressive to 86.6% with the switched structure. For model predictive control, the improvement is from 73.4% and 74.1% to 85.8%. Last, linear quadratic Gaussian control increases from 65.0% and 70.4% to 85.6%. Conclusion The findings suggest that the switched strategy may be a feasible and straightforward approach for enhancing meal compensation without increasing the risk of postprandial hypoglycemia in people with diabetes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

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Saavedra, M.; Inthamoussou, F.; Fushimi, E.; Garelli, F.

Identification of Physical Activity Type in People with Diabetes: A Spectrogram-Based Approach Artículo de revista

En: Diabetes Technology and Obesity Medicine, vol. 1, no 1, pp. 361-373, 2025.

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@article{doi:10.1177/29941520251358842,

title = {Identification of Physical Activity Type in People with Diabetes: A Spectrogram-Based Approach},

author = { M. Saavedra and F. Inthamoussou and E. Fushimi and F. Garelli},

url = {https://www.liebertpub.com/doi/abs/10.1177/29941520251358842},

doi = {10.1177/29941520251358842},

year  = {2025},

date = {2025-07-21},

urldate = {2025-01-01},

journal = {Diabetes Technology and Obesity Medicine},

volume = {1},

number = {1},

pages = {361-373},

abstract = {Background: Individuals with type 1 diabetes (T1D) require close glucose monitoring to prevent both short- and long-term complications. Physical activity (PA) is a significant source of variability in metabolic dynamics, leading to glycemic fluctuations that depend on the type, intensity, and duration of the exercise. Accurately monitoring and classifying the type of PA is crucial for optimizing glycemic control and minimizing the risk of hypoglycemia. Method: This study utilizes the largest clinical trial of PA in people with T1D to date, the Type 1 Diabetes and Exercise Initiative (T1DEXI), which included both structured and unstructured PA sessions, to develop an online classification approach for identifying the type of PA (aerobic, interval, resistance). A computationally efficient convolutional neural network (CNN) was trained on time–frequency representations (spectrograms) of step count and heart rate signals, readily available from wearable devices, from the structured PA sessions of the T1DEXI dataset. The proposed methodology presents an ad hoc process for designing the spectrograms based on the CNN architecture to optimize the classifier’s performance. Results: The CNN-based classification approach was implemented using spectrograms of 5- and 30-min signals, resulting in two classifiers that achieve high classification accuracy when evaluated on the structured PA sessions. The 5-min classifier was then applied to unstructured PA sessions, where the predicted distribution of glucose changes for the activity types was consistent with clinical evidence. Conclusion: These results demonstrate the potential of the proposed approach for its integration into decision support systems or automated insulin delivery systems, enabling improved glucose management during exercise in T1D.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

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Spinelli, E.; Catacora, V.; Guerrero, F.; Haberman, M.

Enhancing CMRR in Fully Differential Amplifiers via Power Supply Bootstrapping Artículo de revista

En: Chips, 2025.

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