Christophe Escriba

Dr. Christophe Escriba

LAAS-CNRS
orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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31 October 2014 in Sensors
Verified
Journal Article
Open access
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HBHamza Boukabache
Hamza Boukabache
CEChristophe Escriba
Christophe Escriba
JFJean-Yves Fourniols
Jean-Yves Fourniols
Structural health monitoring using noninvasive methods is one of the major challenges that aerospace manufacturers face in this decade. Our work in this field focuses on the development and the system integration of millimetric piezoelectric sensors/ actuators to generate and measure specific guided waves. The aim of the application is to detect mechanical flaws on complex composite and alloy structures to quantify efficiently the global structures’ reliability. The study begins by a physical and analytical analysis of a piezoelectric patch. To preserve the structure’s integrity, the transducers are directly pasted onto the surface which leads to a critical issue concerning the interfacing layer. In order to improve the reliability and mitigate the influence of the interfacing layer, the global equations of piezoelectricity are coupled with a load transfer model. Thus we can determine precisely the shear strain developed on the surface of the structure. To exploit the generated signal, a high precision analog charge amplifier coupled to a double T notch filter were designed and scaled. Finally, a novel joined time-frequency analysis based on a wavelet decomposition algorithm is used to extract relevant structures signatures. Finally, this paper provides examples of application on aircraft structure specimens and the feasibility of the system is thus demonstrated.

11 October 2012 in Sensors
Verified
Journal Article
Open access
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HBHamza Boukabache
Hamza Boukabache
CEChristophe Escriba
Christophe Escriba
SZSabeha Zedek
Sabeha Zedek
DMDaniel Medale
Daniel Medale
SRSebastien Rolet
Sebastien Rolet
JFJean-Yves Fourniols
Jean-Yves Fourniols
The work reported on this paper describes a new methodology implementation for active structural health monitoring of recent aircraft parts made from carbon-fiber-reinforced polymer. This diagnosis is based on a new embedded method that is capable of measuring the local high frequency impedance spectrum of the structure through the calculation of the electro-mechanical impedance of a piezoelectric patch pasted non-permanently onto its surface. This paper involves both the laboratory based E/M impedance method development, its implementation into a CPU with limited resources as well as a comparison with experimental testing data needed to demonstrate the feasibility of flaw detection on composite materials and answer the question of the method reliability. The different development steps are presented and the integration issues are discussed. Furthermore, we present the unique advantages that the reconfigurable electronics through System-on-Chip (SoC) technology brings to the system scaling and flexibility. At the end of this article, we demonstrate the capability of a basic network of sensors mounted onto a real composite aircraft part specimen to capture its local impedance spectrum signature and to diagnosis different delamination sizes using a comparison with a baseline.

19 September 2024 in Sensors
Verified
Journal Article
Open access
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ABAugustin Bricout
Augustin Bricout
PLPhilippe LELEUX
Philippe LELEUX
PAPascal Acco
Pascal Acco
CEChristophe Escriba
Christophe Escriba
Fourniols Jean-YvesFourniols Jean-Yves
Fourniols Jean-Yves
RFRémi Floquet
Rémi Floquet
Beehive health monitoring has gained interest in the study of bees in biology, ecology, and agriculture. As audio sensors are less intrusive, a number of audio datasets (mainly labeled with the presence of a queen in the hive) have appeared in the literature, and interest in their classification has been raised. All studies have exhibited good accuracy, and a few have questioned and revealed that classification cannot be generalized to unseen hives. To increase the number of known hives, a review of open datasets is described, and a merger in the form of the “BeeTogether” dataset on the open Kaggle platform is proposed. This common framework standardizes the data format and features while providing data augmentation techniques and a methodology for measuring hives’ extrapolation properties. A classical classifier is proposed to benchmark the whole dataset, achieving the same good accuracy and poor hive generalization as those found in the literature. Insight into the role of the frequency of the classification of the presence of a queen is provided, and it is shown that this frequency mostly depends on a colony’s belonging. New classifiers inspired by contrastive learning are introduced to circumvent the effect of colony belonging and obtain both good accuracy and hive extrapolation abilities when learning changes in labels. A process for obtaining absolute labels was prototyped on an unsupervised dataset. Solving hive extrapolation with a common open platform and contrastive approach can result in effective applications in agriculture.

8 January 2022 in Sensors
Verified
Journal Article
Open access
PDF file
EAEli Gabriel Avina-Bravo
Eli Gabriel Avina-Bravo
JCJohan Cassirame
Johan Cassirame
CEChristophe Escriba
Christophe Escriba
PAPascal Acco
Pascal Acco
Fourniols Jean-YvesFourniols Jean-Yves
Fourniols Jean-Yves
GSGeorges Soto-Romero
Georges Soto-Romero
This paper aims to provide a review of the electrically assisted bicycles (also known as e-bikes) used for recovery of the rider’s physical and physiological information, monitoring of their health state, and adjusting the “medical” assistance accordingly. E-bikes have proven to be an excellent way to do physical activity while commuting, thus improving the user’s health and reducing air pollutant emissions. Such devices can also be seen as the first step to help unhealthy sedentary people to start exercising with reduced strain. Based on this analysis, the need to have e-bikes with artificial intelligence (AI) systems that recover and processe a large amount of data is discussed in depth. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used to complete the relevant papers’ search and selection in this systematic review.

30 November 2020 in Sensors
Verified
Journal Article
Open access
PDF file
CEChristophe Escriba
Christophe Escriba
EAEli Gabriel Avina-Bravo
Eli Gabriel Avina-Bravo
JRJulien Roux
Julien Roux
JFJean-Yves Fourniols
Jean-Yves Fourniols
MCMichel Contardo
Michel Contardo
GSGeorges Soto-Romero
Georges Soto-Romero
Modern agriculture imposes the need for better knowledge of the soil moisture content to rationalize the amount of water needed to irrigate farmlands. In this context, since current technological solutions do not correspond to the cost or use criteria, this paper presents a design for a new original capacitive bi-functional sensor to measure soil moisture and salinity. In this paper, we outline the design stages from simulation to finished elements of the optimal design to deployment in the fields, considering the mechanical integration constraints necessary for industrialization. The measurement electronics were developed based on the sensor’s electric model to obtain a double measurement. An on-site (field lot) measurement program was then carried out to validate the system’s good performance in real-time. Finally, this performance was matched with that of leading commercially available sensors on the market. This work demonstrates that, after deployment of the sensors, the overall system makes it possible to obtain a precise image of cultivated soil’s hydric condition, with the best response time.

18 April 2023 in Sensors
Verified
Journal Article
Open access
PDF file
EAEli Gabriel Avina-Bravo
Eli Gabriel Avina-Bravo
FSFelipe Augusto Sodre Ferreira de Sousa
Felipe Augusto Sodre Ferreira de Sousa
CEChristophe Escriba
Christophe Escriba
PAPascal Acco
Pascal Acco
FGFranck Giraud
Franck Giraud
GSGeorges Soto-Romero
Georges Soto-Romero
This paper presents the development of an electronic system that converts an electrically assisted bicycle into an intelligent health monitoring system, allowing people who are not athletic or who have a history of health issues to progressively start the physical activity by following a medical protocol (e.g., max heart rate and power output, training time). The developed system aims to monitor the health state of the rider, analyze data in real-time, and provide electric assistance, thus diminishing muscular exertion. Furthermore, such a system can recover the same physiological data used in medical centers and program it into the e-bike to track the patient’s health. System validation is conducted by replicating a standard medical protocol used in physiotherapy centers and hospitals, typically conducted in indoor conditions. However, the presented work differentiates itself by implementing this protocol in outdoor environments, which is impossible with the equipment used in medical centers. The experimental results show that the developed electronic prototypes and the algorithm effectively monitored the subject’s physiological condition. Moreover, when necessary, the system can change the training load and help the subject remain in their prescribed cardiac zone. This system allows whoever needs to follow a rehabilitation program to do so not only in their physician’s office, but whenever they want, including while commuting.