Predictive Maintenance on the Machining Process and Machine Tool

This paper presents the process required to implement a data driven Predictive Maintenance (PdM) not only in the machine decision making, but also in data acquisition and processing. A short review of the different approaches and techniques in maintenance is given. The main contribution of this paper is a solution for the predictive maintenance problem in a real machining process. Several steps are needed to reach the solution, which are carefully explained. The obtained results show that the Preventive Maintenance (PM), which was carried out in a real machining process, could be changed into a PdM approach. A decision making application was developed to provide a visual analysis of the Remaining Useful Life (RUL) of the machining tool. This work is a proof of concept of the methodology presented in one process, but replicable for most of the process for serial productions of pieces

Failure Prognosis of Embedded Systems Based on Temperature Drift Assessment

International audienceThe Systems-on-Chip provide a large capacity for calculation and monitoring, so they are increasingly integrated into risky processes such as aeronautical and power generation systems. However, embedded systems are subject to degradation caused by wear, that can be accelerated by the often hostile environment. This paper proposes a method of failure prognosis of embedded systems based on the estimation of the temperature drift under reference operating conditions, then the modelling of the drift trend using a support vector regression model. The remaining useful life is estimated using the integral of the probability density function of the time to failure. Experimental results, evaluated by performance analysis techniques, show the effectiveness of the proposed approach

Effect of natural extracts of a medicinal plant: Pistacia lentiscus on lipid peroxidation

 Medicinal plants are important for pharmacological research and the development of medicines thanks to their active principle which are grouped under metabolites known as secondary metabolites. These researches made it possible to destroy certain legends, but firmly established certain ancient uses for their curative virtues. In this context, we tried to evaluate the antioxidant activity of the extracts prepared from the plant Pistachia lentiscus. Quantitative analysis of the phenolic compounds by a suitable method of Singleton and Ross, 1965 with the Folin-Ciocalteu reagent, giving grades of 0.061 to 0.650 mg EAG / g dry matter. Evaluation of the antioxidant capacity of the extracts with respect to the oxidation of lipids by the AAPH confirms that the dichloromethane extract is the most active with a value of the inhibition rate of 14.67% for linoleic acid and a value of 18.19% for sunflower oil. This result encourages us to study further the compounds of this extract and to isolate the most reactive molecule, to identify it and to determine its toxic effect

A Review in Fault Diagnosis and Health Assessment for Railway Traction Drives

During the last decade, due to the increasing importance of reliability and availability, railway industry is making greater use of fault diagnosis approaches for early fault detection, as well as Condition-based maintenance frameworks. Due to the influence of traction drive in the railway system availability, several research works have been focused on Fault Diagnosis for Railway traction drives. Fault diagnosis approaches have been applied to electric machines, sensors and power electronics. Furthermore, Condition-based maintenance framework seems to reduce corrective and Time-based maintenance works in Railway Systems. However, there is not any publication that summarizes all the research works carried out in Fault diagnosis and Condition-based Maintenance frameworks for Railway Traction Drives. Thus, this review presents the development of Health Assessment and Fault Diagnosis in Railway Traction Drives during the last decade

Phytochemical profile and antimicrobial properties of volatile compounds of Satureja calamintha (L) Scheel from northern Algeria

Purpose: To undertake the phytochemical screening of Satureja calamintha (L.)  Scheel., and evaluate the antimicrobial activities of its volatile compounds.Methods: Qualitative phytochemical analysis of the plant was performed using  standard methods. The extraction of essential oils (EOs) was conducted using  steam distillation, while the chemical composition was determined using gas chromatography-mass spectrometry (GC-MS). The antimicrobial activities of the oils were evaluated against ten bacterial and six fungal strains using disc-diffusion assay and poisoned food technique, respectively.Results: After steam distillation, the extraction yield was 0.54 ± 0.11 %. GC-MS analysis identified approximately 99.99 % of the EOs. The three most abundant compounds identified were l-menthone (32.10 %), neo-menthol (32.07 %) and pulegone (22.35 %). The oils had significant (p < 0.05) antimicrobial activities against the tested bacterial and fungal strains, except Bacillus cereus and Candida albicans. The lowest minimum inhibitory concentration (MIC) for bacteria was 0.007 % (v/v) against Enterococcus faecalis and Klebsiella pneumoniae, whereas for fungi, it was 0.500 % (v/v) against Candida albicans. Moreover, Enterococcus faecalis and Listeria innocua had the lowest minimum bactericidal concentration (MBC) at 0.125 % (v/v), in contrast to the lowest fungicidal concentration (MFC) for Candida albicans at 0.500 % (v/v).Conclusion: These results demonstrate that EOs from Satureja calamintha (L.)  Scheel. possess significant antimicrobial activities which might be useful for  therapeutic and pharmaceutical applications.Keywords: Satureja calamintha, Phytochemicals, Essential oils, Antimicrobial activity, Steam distillatio

An adaptative method for the smothing of curves edge detection application

We present a new approach to smooth discrete curves . The smoothing is realized by associating portions of regular curves which are defined on each points interval . The originality of the method consists in finding the portions of curves by minimizing the squared error over a restricted neighbourhood around each point . Adding continuity constraints at the junction points, we obtain a direct formulation of the solution . A unique parameter allows to easily control the smoothing amplitude which can be selected between two extreme cases : interpolation or approximation . It seems like a drawer behaviour trying to join points by a curve . He can choose to join each point by a curve or only take into account the global form of the set of points . The method is particularly adapted to fit contours defined on an image and is used as a final step of image segmentation process . The parameter controlling the smoothing amplitude is computed from the value of local gradient magnitude on each pixel .La méthode de lissage de courbes discrètes présentée est fondée sur la minimisation d'un critère d'erreur quadratique appliqué sur des portions jointives de la courbe à traiter. En imposant des contraintes géométriques au niveau des points de jonctions entre intervalles, on aboutit à une formulation directe de la solution. Un paramètre unique permet de façon simple de contrôler la force du lissage qui évolue ainsi entre 2 cas extrêmes: l'interpolation et l'approximation. La méthode simule le comportement d'un scripteur cherchant à unir des points par une courbe, il peut privilégier le passage du tracé par chaque point ou au contraire respecter la forme globale définie par l'ensemble des points. Cette méthode adaptative de lissage est utilisée comme étape finale d'un processus de segmentation d'images, le paramètre contrôlant la force du lissage étant défini à partir du gradient mesuré localement en chaque point

Construction and analysis of causally dynamic hybrid bond graphs

Engineering systems are frequently abstracted to models with discontinuous behaviour (such as a switch or contact), and a hybrid model is one which contains continuous and discontinuous behaviours. Bond graphs are an established physical modelling method, but there are several methods for constructing switched or ‘hybrid’ bond graphs, developed for either qualitative ‘structural’ analysis or efficient numerical simulation of engineering systems. This article proposes a general hybrid bond graph suitable for both. The controlled junction is adopted as an intuitive way of modelling a discontinuity in the model structure. This element gives rise to ‘dynamic causality’ that is facilitated by a new bond graph notation. From this model, the junction structure and state equations are derived and compared to those obtained by existing methods. The proposed model includes all possible modes of operation and can be represented by a single set of equations. The controlled junctions manifest as Boolean variables in the matrices of coefficients. The method is more compact and intuitive than existing methods and dispenses with the need to derive various modes of operation from a given reference representation. Hence, a method has been developed, which can reach common usage and form a platform for further study

Review on Health Indices Extraction and Trend Modeling for Remaining Useful Life Estimation

International audienc

Fault diagnosis and prognosis based on physical knowledge and reliability T data: Application to MOS Field-Effect Transistor

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Hydrolyse des protéines végétales (gluten de blé) : caractérisation des propriétés fonctionnelles des hydrolysats

78 p. ; ill. ; 30 cmDans ce mémoire, nous avons caractérisé la matière première (matériel végétal). L'étude a porté sur la fraction protéique de deux variétés de blé tendre ANZA et HD1220. Nous avons déterminé quelques caractéristiques de la farine et du gluten, en commençant par un broyage des blés et une extraction du gluten, le suivi de l'opération était argumentée par des analyses technico-chimiques ainsi par des tests d'appréciation de la qualité du gluten