Node and junction box services and interfaces for a local sea bottom observatory

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A Third order Semi-Implicit Homogeneous differentiator: Experimental Results

International audienceIt is well-known that implicit-based and projectorbased differentiator schemes offer better performances, like reducing high frequency oscillations, compared to the corresponding explicit schemes. To keep the advantages of such implicit Euler approximations, when this approximation is applied in case of homogeneous differentiators, a semi-implicit Euler approximation has been recently proposed for secondorder systems. In this paper, a generalization to third order semi-implicit differentiation is proposed taking into account the attenuation of the noise considering advanced iterative projectors definition. Validation on experimental data is conducted to highlight the well-founded of the proposed differentiation strategy

A Third order Semi-Implicit Homogeneous differentiator: Experimental Results

International audienceIt is well-known that implicit-based and projectorbased differentiator schemes offer better performances, like reducing high frequency oscillations, compared to the corresponding explicit schemes. To keep the advantages of such implicit Euler approximations, when this approximation is applied in case of homogeneous differentiators, a semi-implicit Euler approximation has been recently proposed for secondorder systems. In this paper, a generalization to third order semi-implicit differentiation is proposed taking into account the attenuation of the noise considering advanced iterative projectors definition. Validation on experimental data is conducted to highlight the well-founded of the proposed differentiation strategy

A Third order Semi-Implicit Homogeneous differentiator: Experimental Results

International audienceIt is well-known that implicit-based and projectorbased differentiator schemes offer better performances, like reducing high frequency oscillations, compared to the corresponding explicit schemes. To keep the advantages of such implicit Euler approximations, when this approximation is applied in case of homogeneous differentiators, a semi-implicit Euler approximation has been recently proposed for secondorder systems. In this paper, a generalization to third order semi-implicit differentiation is proposed taking into account the attenuation of the noise considering advanced iterative projectors definition. Validation on experimental data is conducted to highlight the well-founded of the proposed differentiation strategy

An Experimental Investigation of Discretized Homogeneous Differentiators: Pneumatic Actuator Case

International audienc

Experimental validation of two semi-implicit homogeneous discretized differentiators on the CRAFT cable-driven parallel robot

National audienceThis work is dedicated to the application of two differentiating homogeneous semi-implicit to estimate the angular velocity of each of the eight electric motors of the CRAFT cable-driven parallel robot from the recording of the angular position of their respective output shaft. These motors drive the winding or unwinding of eight cables to move the robot moving-platform. The results show that these differentiators, whose definitions are respectively based on one and two projectors, are extremely efficient tools for estimating the angular velocities of the eight motors. These estimated velocities are much less noisy than their reference signals obtained by backward difference. Those promising results will definitely contribute to a better control of the CRAFT robot.Ce travail est dédié à l'application de deux différentiateurs semi-implicites et homogènes pour estimer la vitesse de chacun des huit moteurs électriques du robot parallèle à câbles CRAFT à partir de l'enregistrement de la position angulaire de leur arbre de sortie respectif. Ces moteurs actionnent l'enroulement ou le déroulement de huit câbles pour déplacer la plateforme mobile du robot en translation et en rotation. Les résultats montrent que ces différentiateurs, dont les définitions sont fondées sur un et deux projecteurs, sont des outils performants pour estimer les vitesses angulaires des huit moteurs. Ces vitesses estimées sont beaucoup moins bruitées que leurs signaux de référence obtenus par différence arrière. Ces résultats laissent espérer un apport conséquent pour la commande du robot CRAFT

Experimental validation of two semi-implicit homogeneous discretized differentiators on the CRAFT cable-driven parallel robot

National audienceThis work is dedicated to the application of two differentiating homogeneous semi-implicit to estimate the angular velocity of each of the eight electric motors of the CRAFT cable-driven parallel robot from the recording of the angular position of their respective output shaft. These motors drive the winding or unwinding of eight cables to move the robot moving-platform. The results show that these differentiators, whose definitions are respectively based on one and two projectors, are extremely efficient tools for estimating the angular velocities of the eight motors. These estimated velocities are much less noisy than their reference signals obtained by backward difference. Those promising results will definitely contribute to a better control of the CRAFT robot.Ce travail est dédié à l'application de deux différentiateurs semi-implicites et homogènes pour estimer la vitesse de chacun des huit moteurs électriques du robot parallèle à câbles CRAFT à partir de l'enregistrement de la position angulaire de leur arbre de sortie respectif. Ces moteurs actionnent l'enroulement ou le déroulement de huit câbles pour déplacer la plateforme mobile du robot en translation et en rotation. Les résultats montrent que ces différentiateurs, dont les définitions sont fondées sur un et deux projecteurs, sont des outils performants pour estimer les vitesses angulaires des huit moteurs. Ces vitesses estimées sont beaucoup moins bruitées que leurs signaux de référence obtenus par différence arrière. Ces résultats laissent espérer un apport conséquent pour la commande du robot CRAFT

La Bouée MOLIT : un nouveau concept de bouée instrumentée

La validité du concept de station de mesure haute-fréquence Marel a été vérifié par le déploiement d’un réseau constitué de stations de type axisymétrique (Réseau Baie de Seine, Bouée Iroise en rade de Brest). Le mouillage et le comportement de ces bouées en terme d’accessibilité et de maintenance est un handicap pour l’extension vers les zones plus exposées du large. La bouée MOLIT (Mer Ouverte LITtorale) constitue une réponse technique et financière

Node and junction box services and interfaces for a local sea bottom observatory

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