Les mesures d'émission acoustique appliquées aux moteurs d'automobiles de collection patrimoniale comme outil de diagnostic avant la remise en fonctionnement: étude réalisée dans le cadre du projet de recherche ACUME-HV au Musée National de l'Automobile de Mulhouse (Collection Schlumpf)

Le Musée National de l’Automobile – Collection Schlumpf mène depuis plusieurs années une politique de remise ou de maintien en fonctionnement de certaines automobiles de la collection. Si ces remises en fonctionnement présentent de nombreux avantages, elles ne sont pas sans risques. Aussi, différentes méthodes ont été développées par des institutions patrimoniales de par le monde. L’émission acoustique constituerait une méthode scientifique complémentaire qui, appliquée sur un moteur avant son démarrage, permettrait de connaitre son état et donc de décider ou non de sa remise en fonctionnement. Cette technique a été appliquée sur trois moteurs, tous semblables afin de pouvoir comparer les données obtenues. Le premier moteur est un moteur test sans statut patrimonial. Il s’agit d’un moteur Renault deux cylindres de type AG1 (v.1906 -1916). Il a permis de se familiariser avec le matériel, de mettre en place un protocole et de simuler des pannes afin de créer une référence pour les essais suivants. Le second moteur est un moteur d’une automobile de collection patrimoniale (Inv.2209). En raison de son statut, la réversibilité de cette technique et l’innocuité des matériaux utilisés a également été testée. Les essais d’émission acoustique effectués ont permis de confirmer son bon état général, tout en diagnostiquant une légère fuite qui n’était pas connue. Enfin, comme ces essais sur un moteur en bon état ont été concluant, le choix a été fait de faire une dernière vague de tests sur un moteur connu pour être en mauvais état et appartenant à une automobile d’animation sans statut patrimonial (Inv.7003). L’émission acoustique a donc confirmé les états supposés de ces deux moteurs. Les essais se sont tous déroulés à froid et il serait ainsi intéressant d’aller au-delà, en testant cette technique sur des moteurs à chaud. En raison de sa sensibilité et de sa complexité, cette technique nécessiterait la création d’une base de donnée afin de faciliter l’interprétation des essais.The National Car Museum of Mulhouse (Schlumpf Collection) is carring out since many years a politic to keep running or start again a part of the collection. It has many advantages but do not come without risks. That’s why methods to restart engines have been developed by many institutions worldwide. Acoustic emission could be a good complement to such methods as far as it allows to know the state of the engine before deciding if it could be restarted or not. The acoustic emission has been applied on three similar engines to compare the results. The first one was a two-cylinder engine of a Renault AG1 without heritage regulation mounted on a bench test in order to determine a protocol and simulate breakdowns. The second one was a heritage car from the collection (Inv.2209), on which the reversibility of these methods was also tested. The test attested the good state of the engine and even allow us to find a breakdown we didn’t suspect. Therefore, other tests were done on another engine (Inv.7003), which was supposed to be in a bad state. The acoustic emission reinforces the conclusion of the maintenance tracking reports. However, this technique is very complex and sensitive, so more research work should have to be done to get an easier understanding of the results

Troubles du comportement alimentaire : à la recherche du support neurohormonal d'une toxicomanie singulière

Anorexia nervosa is a condition caracterized by a relentless preoccupation with dieting and weight loss that results in severe emaciation and can lead to death. Although the origin of anorexia nervosa remains obscure, symptoms are related to the convergence of environmental and psychosocial influences on genetically sensitive individuals. Recent brain-imaging techniques are providing new insights into limbic and cognitive neural circuits dysfunctions affecting anorexic patients and the role of serotonin and dopamine metabolism. The implications of the 5HT4 serotoninergic receptor point to common neuronal pathways between addictive disorders and eating disorders. These alterations in cerebral activity permit to better understand the puzzling symptoms found in anorexia nervosa and raise the question : Is anorexia nervosa a peculiar form of addiction

Diagnostic and monitoring of historical vehicle engines by acoustic emission testing

The ACUME project aims at developing a non-invasive diagnostic tool for the engines of historical vehicles conserved in museums and collections. This tool will help conservator-restorers to make a decision and implement the reactivation of engines stopped for long time. The Acoustic Emission (AE) technique allows to detect malfunctions before they are audible by human ear. It is used in the field of automotive industry for the diagnostic of new engines and in different fields of cultural heritage for the evaluation of historical objects and artworks

Running historical engines safely

The aim of the research project, entitled Acoustic Emission Moni-toring of Historical Vehicles (ACUME_HV), is to develop a diag-nostic tool to help people in charge of historical vehicles (conser-vators, technicians, mechanics...) during the condition report and the maintenance of the engines. Ancient vehicles can be conserved statically or working. In this second option, historical vehicles can be started or used more or less frequently, depending on the purpose of the museum or the private collection. However, heritage institu-tions have always the responsibility to maintain the vehicle in a safe condition, for the artefact itself as well as for the driver, passengers and for the public

Acoustic emission techniques for the detection of simulated failures in historical vehicles engines

Technical and industrial heritage artefacts are characterized by the presence of mechanisms. The possibility to activate, or reactivate, these mechanisms is an integral part of the cultural values of this kind of patrimony. The artefacts’ functionality, however, requires an effective diagnostic in order to detect the onset of malfunctioning at a very early stage to avoid wear and breakdowns. The assessment of moving mechanisms of heritage objects may be performed using non-destructive methods, such as acoustic emission (AE). The ACUME_HV project aimed at developing diagnostic and monitoring protocols for historical vehicles’ engines using AE techniques. The case studies were performed on 2-cylinders Renault AG1 vehicles (collection of the “Musée National de l’Automobile – Collection Schlumpf” of Mulhouse, France). These cars are maintained in working conditions, and their engines are started periodically. After a first phase consisting in recording the reference signals of the selected engines, the project focused on detecting faults simulated on purpose, the latter reproducing common failures occurring in historical vehicles’ engines

Fault detection and diagnosis of historical vehicle engines using acoustic emission techniques

The reactivation of artefact mechanisms is always a challenge for conservators. Non-invasive diagnostic techniques, applicable directly on the artifacts, allows for performing early-stage diagnostics and avoiding damage. The Acoustic Emission Monitoring of Historical Vehicles (ACUME_HV) project represents the first use of acoustic emission (AE) as a non-invasive technique for the diagnostics of historical vehicles. The aim of this project is to develop an objective, human-independent method. This will help museum personnel to make decisions regarding the reactivation of historical vehicle engines using measurements and data analysis rather than merely personal experience. Herein, we present the results of the first phase of the ACUME_HV project, which was focused on the development of a protocol for the use of AE during cold tests

Data analysis techniques for the visualization and classification of historical vehicle engines’ health status using data-driven solutions

In the field of cultural heritage, the use of non-destructive techniques to determine the state of conservation of an artifact is of the utmost importance, to avoid damage to the object itself. In this paper, we present a data pipeline and several machine learning techniques for the visualization, analysis and characterization of engines in historical vehicles. The paper investigates the use of vibro-acoustic signals acquired from the engines in different states of conservation and working conditions to train machine learning solutions. Data are classified according to their state of health and the presence of anomalies. The t-SNE algorithm is used for dimensionality reduction for data visualization. The machine learning algorithms tested showed encouraging performance in associating acoustic emission data with the engine signature, the type of anomaly and the working conditions. Nevertheless, a larger dataset would allow us to improve and strengthen the results.Em património cultural a utilização de técnicas não destrutivas para determinar o estado de conservação de um artefacto é de extrema importância para evitar danos no próprio objeto. Neste artigo, apresentamos um canal de dados e técnicas de aprendizagem automática para a visualização, análise e caraterização de motores de veículos históricos. O artigo investiga a utilização de sinais vibro-acústicos adquiridos nos motores em diferentes estados de conservação e condições de funcionamento para treinar soluções de aprendizagem automática. Os dados são classificados de acordo com o seu estado de conservação e a presença de anomalias. O algoritmo t-SNE utilizou-se para a redução da dimensionalidade para a visualização dos dados. Os algoritmos de aprendizagem automática testados revelaram um desempenho promissor na associação dos dados de emissões acústicas com a assinatura do motor, o tipo de anomalia e as suas condições de funcionamento. Porém, um maior conjunto de dados permitir-nos-ia melhorar e reforçar os resultados

Diagnostic of historical vehicle’s engines by acoustic emission techniques

The reactivation of artefacts’ mechanisms is always a challenge for conservators and proper noninvasive diagnostic techniques, applicable directly on the artifacts, allows to perform a precocious diagnostic and to avoid damages. The ACUME_HV project (Acoustic Emission Monitoring of Historical Vehicles) represents the first use of acoustic emission (AE) as non-invasive technique for the diagnostic of historical vehicles. The aim of this project is to propose an objective, human-independent method that will help the personnel of the museums to take decisions concerning the reactivation of the historical vehicles’ engines using measurements and data and not only personal experience. In this paper the results of the first phase of the ACUME_HV project are presented. This first phase focused on the development of a protocol for the use of AE during cold tests

Acoustic Emission Monitoring as a Non-invasive Tool to Assist the Conservator in the Reactivation and Maintenance of Historical Vehicle Engines

Historical cars are an important part of the cultural heritage of the last 150 years. Their preservation in technical museums raises the question of how to preserve their primary functionality, namely their mobility. This implies being able to reactivate and to maintain their thermal engines, which are the source of their motion. However, the diversity and complexity of these engines generally require the presence of highly qualified personnel as well as detailed condition reports to assist the conservators. This study proposes to use acoustic emission techniques to facilitate these conservation procedures by objectifying the evaluation of the state of the engines and by providing systematic quantitative indicators for their health monitoring. To illustrate the implementation and the potentialities of this approach, different tests have been carried out at the National Automobile Museum of Mulhouse, on a Renault Type AG1. A dedicated experimental setup and the associated measurement protocol are presented in this paper. The derived results show the ability of this method to detect specific types of engine malfunctions, both during bench test and in situ measurement conditions. A critical discussion is finally proposed to highlight the feasibility and the possibilities of such laboratory techniques in the context of conservation assistance

Long-term use of antipsychotics in community-dwelling dementia patients

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