PEOPLE@HES-SO Directory and Skills inventory

Role: Co-applicant

Requérant(e)s: IAI, Herzog Raoul, IAI

Financement: HES-SO Rectorat

Description du projet : Un des défis majeurs d'une micro/mini-machine d'usinage concerne le compromis idéal entre la productivité (diminution du temps de cycle), la consommation d'énergie pour effectuer l'usinage, et la qualité de la pièce usinée. Cette qualité s'exprime dans les domaines de la précision et de l'état de surface obtenus. Le compromis entre la productivité et la consommation d'énergie est aujourd'hui résolu au niveau théorique pour le cas de machines à corps rigides ("fully actionated"), mais il manque son application dans le domaine du micro-usinage. L'inclusion de modes vibratoires et du critère "état de surface" est primordiale pour le procédé de micro-usinage, mais elle n'est pas traitée à ce jour dans le sens d'une optimisation. L'approche duale structurelle/contrôle d'une machine-outil permet d'obtenir des compromis optimaux en termes de performances dynamiques, de qualité d'usinage, mais également de consommation énergétique de la machine pour la réalisation du procédé. Ceci tant du point de vue du procédé lui-même, que du point de vue des mouvements d'axes hors usinage qui sont réalisés avec les accélérations élevées nécessaires à la garantie d'une productivité compétitive. Cette approche, utilisée dans le projet I1 TrajOpt pour aborder la question de l'architecture de machine optimale en termes de performance dynamique de machine, est étendue ici pour inclure les aspects suivants au procédé de micro-usinage : consommation d'énergie en mouvements d'axes et qualité de surface obtenue. Afin d'inclure sous une approche d'optimisation de la qualité d'état de surface, il s'agit notamment d'exprimer l'état de surface au moyen d'analyses de type densités spectrales (ex. PSD) dans l'espace de Fourier, autocorrélation AC ou encore des fonctions plus spécifiques comme la Two-quadrant Area Structure Function (ASF), qui peuvent ensuite être mises en relation avec le comportement vibratoire de la machine. L'objectif de ce projet consiste à formaliser une approche d'optimisation (paramètres de contrôle et structure) visant à minimiser la consommation énergétique en tenant compte des contraintes de productivité et de qualité d'état de surface de la pièce à usiner.

Research team within HES-SO: Jeannerat Claude , Pakpoor Gilani Nima Nicolas , Blanc Philippe , Bonhôte Philippe , Fatio Benoît , Jacquod Nicolas , Marchand Yoan , Jobin Marc , Clivaz Romain , Loehr Bernard , Schorderet Alain , Moutarlier Nicolas , Herzog Raoul

Partenaires académiques: IAI; COMATEC; hepia inSTI; Conception des moyens de production; Herzog Raoul, IAI

Durée du projet: 01.01.2015 - 31.12.2017

Montant global du projet: 230'470 CHF

Statut: Completed

MicroMac_Dev

Caractérisation expérimentale comparative des performances énergétiques et fonctionnelles de plusieurstypologies de machines-outils.

Role: Co-applicant

Requérant(e)s: Conception des moyens de production, Jeannerat Claude, Conception des moyens de production

Financement: HES-SO Rectorat

Description du projet : Le projet MICROMAC_DEV s'inscrit dans le programme de recherche intitulé « EcoSwissMade» dans l'axe « Microfactory ». Après l'étude de faisabilité menée dans le projet MicroMac_Study, nous proposons de poursuivre le développement d'une micromachine d'une taille adaptée à la taille des pièces qu'elle fabriquera. Cette micromachine pourra être dédiée à l'usinage par enlèvement de copeaux pour la fabrication de platines horlogères mais pourra également accueillir des composants spécifiques pour d'autres procédés (électroérosion, ultrasons')....

Research team within HES-SO: Golay Fabien , Jeannerat Claude , Birling François , Pakpoor Gilani Nima Nicolas , Briquez Valérie , Montavon Raphaël , Marchand Yoan , Weil Philippe , Richard Jacques , Schorderet Alain , Moutarlier Nicolas , Schaller Renaud

Partenaires académiques: IAI; COMATEC; hepia inSTI; Conception des moyens de production; Jeannerat Claude, Conception des moyens de production

Durée du projet: 15.11.2014 - 31.10.2017

Montant global du projet: 235'840 CHF

Statut: Completed

Role: Co-applicant

Requérant(e)s: hepia inSTI, Haas Patrick, hepia inSTI

Financement: HES-SO Rectorat

Description du projet : Le projet EcoCarac s'inscrit dans l'axe Microfactory du programme EcoSwissmade. Il vise à évaluer les performances fonctionnelles et énergétiques réelles de machines standards et orientées Eco. Cette caractérisation expérimentale, basée sur la réalisation d'une pièce test et des mesures dédiées permettra d'évaluer, au moyen d'un ensemble équipement-protocole identique, des valeurs de gains énergétiques et d'encombrement obtenus par une machine orientée Eco.

Research team within HES-SO: Pontelandolfo Piero , Golay Fabien , Jeannerat Claude , Bergerat Sylvain , Pakpoor Gilani Nima Nicolas , Bonhôte Philippe , Fatio Benoît , Steulet Mathieu , Schneiter Justine , Marchand Yoan , Haas Patrick , Richard Jacques , Schorderet Alain , Moutarlier Nicolas , Balistreri Christophe

Partenaires académiques: Conception simulation; COMATEC; hepia inSTI; Haas Patrick, hepia inSTI

Durée du projet: 01.11.2015 - 30.09.2017

Montant global du projet: 223'000 CHF

Statut: Completed

Micromac_Study

Génération de profils de mouvement temps optimaux pour des micro-machines d'usinage, en tenant compte des fréquences propres de la machine, des tolérances géométriques de la pièce et des contraintes m

Role: Co-applicant

Requérant(e)s: Conception des moyens de production, Briquez Valérie, Conception des moyens de production

Financement: HES-SO Rectorat

Description du projet : Programme Instrument I1 : MICROMAC_STUDY s'inscrit dans le programme de recherche intitulé «EcoSwissMade», Microfactory. Il consiste à mener une étude préliminaire permettant de définir un cadre optimal pour la réalisation de micromachines de fabrication. Cette étude débutera par un état de l'art «Microfactories». L'étude des différents procédés permettra de réaliser un cahier des charges spécifique à chacun d'eux et d'analyser la concordance en besoins fonctionnels et techniques. Pour l'usinage par enlèvement de copeaux, nous focaliserons notre démarche sur une micromachine capable de fabriquer une platine horlogère. Elle pourra travailler un cube de 50mm de côté. Selon le ratio visé de 1/5, elle devra donc s'inscrire dans un cube de 250mm de côté pour sa partie structurelle principale. Une recherche de l'architecture optimale pour atteindre le ratio cité ci-dessus sera également menée. Une caractérisation de l'écoconception dans le domaine microtechnique permettra d'établir des critères de travail

Research team within HES-SO: Jeannerat Claude , Bergerat Sylvain , Birling François , Vermot Eddy , Briquez Valérie , Montavon Raphaël , Richard Jacques , Schorderet Alain , Moutarlier Nicolas

Partenaires académiques: COMATEC-CO; hepia inSTI; Conception des moyens de production; Briquez Valérie, Conception des moyens de production

Durée du projet: 15.01.2014 - 30.09.2016

Montant global du projet: 228'000 CHF

Statut: Completed

Role: Collaborator

Requérant(e)s: IAI, Herzog Raoul, IAI

Financement: HES-SO Rectorat

Description du projet : Une micro-machine d'usinage est prédestinée à fabriquer des grandes séries de petites pièces. La productivité d'une telle machine dépend largement de la capacité de pouvoir générer des profils de mouvement précis en "temps optimal", en respectant les tolérances géométriques et états de surfaces requis pour la pièce à usiner, et en exploitant au maximum les contraintes mécatroniques de la machine et du processus (vitesse max, accélération max, jerk max). Le problème d'optimisation résultant est à large échelle et incorpore le modèle dynamique de la machine y-c ses modes propres. Le projet tire parti des avancées récentes dans le domaine de la l'optimisation convexe séquentielle (SCP) et de la disponibilité de puissance de calcul de plus en plus élevée. Ce projet vise a) à effectuer des analyses de compliance permettant de choisir une architecture de machine appropriée b) à développer des algorithmes d'optimisation robustes et rapide, et de les tester sur un démonstrateur

Research team within HES-SO: Blanc Philippe , Bonhôte Philippe , Briquez Valérie , Schorderet Alain , Moutarlier Nicolas , Herzog Raoul

Partenaires académiques: IAI; COMATEC; Conception des moyens de production; Herzog Raoul, IAI

Durée du projet: 26.01.2014 - 01.06.2015

Montant global du projet: 185'000 CHF

Statut: Completed

2019

Development of a new embedded dynamometer for the measurement of forces and torques at the ski-binding interface

Scientific paper ArODES

Frédéric Meyer, Alain Prenleloup, Alain Schorderet

Sensors, 2019, vol. 19, no. 19, article no. 4324

Summary:

In alpine skiing, understanding the interaction between skiers and snow is of primary importance for both injury prevention as well as performance analysis. Risk of injuries is directly linked to constraints undergone by the skier. A force platform placed as an interface between the ski and the skier should allow a better understanding of these constraints to be obtained to thereby develop a more reliable release system of binding. It should also provide useful information to allow for better physical condition training of athletes and non-professional skiers to reduce the risk of injury. Force and torque measurements also allow for a better understanding of the skiers’ technique (i.e., load evolution during turns, force distribution between left and right leg…). Therefore, the aim of this project was to develop a new embedded force platform that could be placed between the ski boot and the binding. First, the physical specifications of the dynamometer are listed as well as the measurement scope. Then, several iterations were performed on parametric 3D modeling and finite element analysis to obtain an optimal design. Two platforms were then machined and equipped with strain gauges. Finally, the calibration was performed on a dedicated test bench. The accuracy of the system was between 1.3 and 12.8% of the applied load. These results show a very good linearity of the system, which indicate a great outcome of the design. Field tests also highlighted the ease of use and reliability. This new dynamometer will allow skiers to wear their own equipment while measuring force and torque in real skiing conditions.

2013

Survivability of integrated PVDF film sensors to accelerated ageing conditions in aeronautical/aerospace structures

Scientific paper ArODES

E. Guzman, Joël Cugnoni, Thomas Gmür, Philippe Bonhôte, Alain Schorderet

Smart Materials and Structures, 2013, vol. 22, no. 6, 12 p.

Summary:

This work validates the use of integrated polyvinylidene fluoride (PVDF) film sensors for dynamic testing, even after being subjected to UV-thermo-hygro-mechanical accelerated ageing conditions. The verification of PVDF sensors' survivability in these environmental conditions, typically confronted by civil and military aircraft, is the main concern of the study. The evaluation of survivability is made by a comparison of dynamic testing results provided by the PVDF patch sensors subjected to an accelerated ageing protocol, and those provided by neutral non-aged sensors (accelerometers). The available measurements are the time-domain response signals issued from a modal analysis procedure, and the corresponding frequency response functions (FRF). These are in turn used to identify the constitutive properties of the samples by extraction of the modal parameters, in particular the natural frequencies. The composite specimens in this study undergo different accelerated ageing processes. After several weeks of experimentation, the samples exhibit a loss of stiffness, represented by a decrease in the elastic moduli down to 10%. Despite the ageing, the integrated PVDF sensors, subjected to the same ageing conditions, are still capable of providing reliable data to carry out a close followup of these changes. This survivability is a determinant asset in order to use integrated PVDF sensors to perform structural health monitoring (SHM) in the future of full-scale composite aeronautical structures.

2011

Identification of the elastic and damping properties in sandwich structures with a low core-to-skin stiffness ratio

Scientific paper ArODES

Marco Matter, Thomas Gmür, Joël Cugnoni, Alain Schorderet

Composite Structures, 2011, vol. 93, no. 2, pp. 331-341

Summary:

A mixed numerical–experimental identification procedure for estimating the storage and loss properties in sandwich structures with a soft core is developed. The proposed method uses at the experimental level a precise measurement setup with an electro-dynamic shaker and a scanning laser interferometer, and at the computational level an original structurally damped shell finite element model derived from the higher-order shear deformation theory with piecewise linear functions for the through-the-thickness displacement. The parameter estimation is derived from adequate objective functions measuring the discrepancy between the experimental and numerical modal data. Through a sensitivity analysis it is shown that for sandwich structures with a soft core only one specimen is required for characterizing the dominant properties of both the core and the skins. The procedure is then applied to two test cases for which all the influent elastic properties and the major damping parameters could be estimated with a fairly good precision.

2010

A PSDT shell finite element formulation including structural damping

Scientific paper ArODES

Marco Matter, Thomas Gmür, Joël Cugnoni, Alain Schorderet

Computers Structures, 2010, vol. 88, no. 15–16, pp. 902-908

Summary:

This paper describes efficient C0-compatible finite elements for modelling structurally damped laminated composite plates and shells under harmonic vibrations. Based upon a shear deformation theory of any order p (PSDT), the elements are well adapted for evaluating, from given elastic and damping properties of the material, the global modal response (mode shapes, natural frequencies and modal loss factors) of multilayered structures. Numerical test cases are presented in order to validate the proposed formulation. Results show that this shell model is accurate and more efficient than the 3D solid formulation for analyzing thin to moderately thick structurally damped plates or shells.

2009

Numerical-experimental identification of the elastic and damping properties in composite plates

Scientific paper ArODES

Marco Matter, Thomas Gmür, Joël Cugnoni, Alain Schorderet

Composite Structures, 2009, vol. 90, no. 2, pp. 180-187

Summary:

A novel method is presented for estimating the elastic and dissipative parameters of composite plates and shells through a mixed numerical-experimental identification procedure based on the natural frequencies, modal damping factors and mode shapes of the specimen under investigation. The modal quantities are measured with an optimized contact-free experimental setup using a loudspeaker for exciting the structure and a scanning laser interferometer for measuring the dynamic response. The corresponding numerical predictions are obtained with an accurate shell element model derived from the higher-order shear deformation theory and including a structural damping mechanism. Adequate objective functions relying on the discrepancy between the experimental and numerical modal data are developed for the parameter estimation. The proposed procedure is next applied to three test cases and the results obtained show that all the elastic properties and the major damping parameters can be estimated with a high accuracy.

2007

Inverse method based on modal analysis for characterizing the constitutive properties of thick composite plates

Scientific paper ArODES

Joël Cugnoni, Thomas Gmür, Alain Schorderet

Computers Structures, 2007, vol. 85,no. 17–18, pp. 1310-1320

Summary:

This paper presents a powerful method for evaluating the constitutive properties of composite laminates through a mixed numerical–experimental identification procedure based on both the extracted mode shapes and the corresponding natural frequencies of the structure. The modal quantities are measured with a precise contact-free experimental technique and extracted numerically with an accurate shell element derived from the higher order shear deformation theory. The elastic properties are estimated with a nonlinear least squares algorithm applied to modal identification criteria. With this novel approach of combining frequency and mode based error norms, the proposed identification method allows an accurate identification of both in-plane and transverse elastic properties with a single non-destructive test. The effectiveness of the procedure is highlighted by test cases on moderately thick to thick plates.

Improved modal characterization of the constitutive parameters in multilayered plates

Scientific paper ArODES

Marco Matter, Thomas Gmür, Joël Cugnoni, Alain Schorderet

Composites Science and Technology, 2007, vol. 67, no. 6, pp. 1121-1131

Summary:

This paper presents an accelerated modal numerical–experimental identification method for estimating the elastic parameters in multilayered composite plates. The proposed algorithm is based upon a contact-free measurement setup and a finite element model including a shear deformation theory of variable order. By minimizing selectively, according to the nature of the parameter, the residuals between the numerical and experimental frequencies and mode shapes, the method takes advantage of the sensitivity of the constitutive properties on the modal data. This optimization in two steps instead of a traditional one-step approach improves the accuracy of the elastic parameters estimated and enhances the convergence rate of the characterization method, as shown in two test cases applied to a unidirectional multilayered carbon/epoxy plate.

2004

Modal validation of a set of C0-compatible composite shell finite elements

Scientific paper ArODES

Joël Cugnoni, Thomas Gmür, Alain Schorderet

Composites Science and Technology, 2004, vol. 64,no. 13–14, pp. 2039-2050

Summary:

This paper presents efficient C0-compatible finite elements for modelling laminated composite shells under free vibrations. Derived from the first-order shear deformation theory (equivalent single-layer laminate model), the elements are well adapted for evaluating the global dynamic response (natural frequencies and mode shapes) of moderately thick multilayered shells. The components of their structural matrices are based on an exact integration per layer, which results in a higher solution accuracy than with standard explicit through-the-thickness schemes. The described finite element formulation, which can be easily implemented in commercial finite element codes, is next validated by means of several experimental modal test cases on thin to relatively thick plates or shells.

Identification by modal analysis of composite structures modelled with FSDT and HSDT laminated shell finite elements

Scientific paper ArODES

Joël Cugnoni, Thomas Gmür, Alain Schorderet

Composites Part A: Applied Science and Manufacturing, 2004, vol. 35, no. 7–8, pp. 977-987

Raoul Herzog, Alain Schorderet, Daniel Rossier

Summary:

This paper presents an improvement and an extension to modal analysis of an existing multilayered composite shell finite element. Generalising the formulation to a set of elements, the proposed models are based upon the first- and higher-order shear deformation theories and are well suited for evaluating the global dynamic response of thin and thick laminated shells respectively. Characterized by a through-the-thickness displacement approximation of a freely chosen order, they display excellent convergence properties when the polynomial order is increased and present a higher computational effectiveness in comparison to the classical layerwise models. The models considered are compared to closed-form solutions based on the layerwise plate theory and the so-called zig–zag formulation. Experimental and numerical modal test cases on thin and thick plates are next investigated in order to validate the proposed shell models. Good agreement is found with the analytical, experimental and numerical references.

2022

OpenCN :

Conference ArODES

une commande numérique ouverte pour des applications à haute performance

Actes de la conférence Manufacturing'21, 19-20 octobre 2022, Paris, France

Stefano Carrino, Jonathan Guerne, Jonathan Dreyer, Hatem Ghorbel, Alain Schorderet, Raphaël Montavon

Summary:

Les commandes numériques (CNC) du marché sont des boîtes noires où l'utilisateur n'a quasiment aucun accès aux algorithmes de planification de trajectoires. LinuxCNC est une commande libre et ouverte, mais pas adaptée pour l'usinage à haute performance, car sans contrôle du jerk. OpenCN surmonte ces limitations avec une optimisation de trajectoires en deux étapes : 1. optimisations géométriques comprenant entre autres un lissage optimal des transitions avec une continuité géométrique de type G2 . 2. optimisation temporelle avec contrôle du jerk, basée sur un problème d'optimisation convexe de type LP appliqué sur un horizon reculant. Les algorithmes sont codés et testés sur Matlab avec une génération automatique du code embarqué C/C++. Le framework OpenCN est constitué d’un environnement de type Linux asymétrique (AMP), avec un noyau récent, et d’une version revisitée de l’extension temps-réel Xenomai/Cobalt. Les plateformes HW supportées sont x86, Raspberry Pi, Zynq® Ultrascale+, et QEMU/virt64 offrant ainsi la possibilité d’exécuter le framework dans un environnement émulé. Un maître EtherCAT libre est inclus, permettant la transmission fiable de consignes aux drives avec une cadence de 10 kHz grâce à l'horloge distribuée (DC). Une validation fonctionnelle de OpenCN est présentée sur une mini fraiseuse 3 axes très performante, dont la première fréquence propre est supérieure à 180 Hz. Les tests ont été effectués sur des pièces fraisées en laiton jusqu'à des vitesses d'avance de F9000. Un module cinématique pour des machines 5 axes est en cours de développement.

2020

Machining quality prediction using acoustic sensors and machine learning

Conference ArODES

Proceedings of the 14th International Conference INTER-ENG 2020 Interdisciplinarity in Engineering, 8–9 October 2020, Mures, Romania

Summary:

The online automatic estimation of the quality of products manufactured in any machining process without any manual intervention represents an important step toward a more efficient, smarter manufacturing industry. Machine learning and Convolutional Neural Networks (CNN), in particular, were used in this study for the monitoring and prediction of the machining quality conditions in a high-speed milling of stainless steel (AISI 303) using a 3mm tungsten carbide. The quality was predicted using the Acoustic Emission (AE) signals captured during the cutting operations. The spectrograms created from the AE signals were provided to the CNN for a 3-class quality level. A promising average f1-score of 94% was achieved.

2019

Productivity increase of high precision micro-milling by trajectory optimization

Conference ArODES

Alain Schorderet, Raoul Herzog, Nicolas Jacquod, Yoan Marchand, Christophe Prongué

MM Science Journal ; Proceedings of 15th International Conference on High Speed Machining, 8-9 October 2019, Prague, Czech Republic

Summary:

Milling parts for watch, medical, aircraft or molds industries is a compromise between time and precision or surface quality. The latter is very often related to machine vibrations during the process. This paper summarizes results obtained with two approaches aiming at reducing machine vibrations caused by axes accelerations. Both are control model based, taking into account the machine's modal behavior. The first algorithm optimizes the acceleration profile, while the second manages the axes cross-talk vibrations. A high-end 5-axis machine tool was used to mill 8 mm square pockets in brass with a 1 mm diameter tool and using a 0.05 mm depth of cut. Standard CNC parameters as well as vibration reduction options were evaluated. Then the two proposed algorithms were implemented on the same machine-tool using a laboratory Matlab based CNC. This paper describes the significant improvements provided by the algorithms when compared to a high end CNC. In the case of milling reference square pockets, up to 90% vibration amplitude reduction were achieved for a given feed rate, and a 5-fold decrease in the pockets machining time was obtained for the same surface quality.

The impact of size reduction on the energy efficiency, dynamics and machining performances in milling

Conference ArODES

Patrick Haas, Alain Schorderet, Claude Jeannerat, Jacques Richard, Christophe Balistreri, Nima Nicolas Pakpoor Gilani

MM Science Journal ; Proceedings of 15th International Conference on High Speed Machining, 8-9 October 2019, Prague, Czech Republic

Summary:

The Micro5 5-axes milling machine was specifically developed for micro, or mini, technical productions and focused on simplicity and efficiency. It provides functional, qualitative and economical performances. Designed for low cutting forces (HSC technology), it has an excellent dynamics. The first vibration modes and compliances being very high, the machine is insensitive to axes accelerations. It therefore produces excellent surface finishes and high efficiency in finishing. This paper presents the results of an evaluation project. A comparison with a usual size machine is made.

2006

Modal identification of the elastic properties in composite sandwich structures

Conference ArODES

Marco Matter, Thomas Gmür, Joël Cugnoni, Alain Schorderet

Proceedings of the Composites Testing and Model Identification 2006 - CompTest2006