System Engineering for dependency analysis - a Bayesian approach: application to obsolescence study

International audienceThroughout its life cycle, systems undergo several modifications in their architecture. These changes target at remaining competitive and responding quickly to new customer requirements. However, any entity change (i.e. component, function or functionality) can produce unexpected consequences, propagated throughout the whole system architecture. It is then necessary to model, predict and control them. System engineering tools and techniques allow dealing with complex systems design. That is why we have developed a novel methodology to analyze changes using a system engineering methodology called ARCADIA, developed by Thales and its associated software Capella. The obtained models allow mapping various kinds of dependencies within a system architecture. The method, presented in this paper, shows how these models are used to integrate change propagation and transform them into Bayesian networks. A set of experiments allows then to obtain insightful pieces of knowledge about the changes propagation. An illustrative case is developed with a focus of particular changes caused by obsolescence of component, function or functionality

Dynamic modeling of spindle-rolling bearings systems in peripheral milling operations

In High-Speed Milling Process (HSM) the machining precision is directly affected by spindle bearing system which has a crucial role and it impacts directly the dynamic performance of the machining system. This study is about an accurate simulation of such system response. In fact, the Timoshenko beam theory with different circular sections is used to propose a finite element model of the spindle system. The effect of the rolling bearings and the gyroscopic moment at high speeds as well as the centrifugal forces and the cutting forces are considered in the formulation. The rigid and flexible movements of the spindle are taken into account. The dynamic responses of tool-tip under the dynamic cutting forces are numerically investigated

Pre-designing of a mechatronic system using an analytical approach with dymola

This paper presents a pre-dimensioning method applied to a mechatronic system and regarding the vibrational aspect, through a simple modeling process in Dymola environment. We study the vibration transmission between dynamic exciters (motors) and receivers (electronic cards) which are located on a simply supported rectangular plate, using an analytical approach. This new method will allow us to perform representative and robust modeling and simulation. The solution for this issue would be a pre-sizing and pre-positioning procedure. It aims to determine a set of possible technical solutions and principal characteristics before the definitive choice of components and precise sizing of the system. The presented method predicts also behaviour of the mechatronic system. In order to validate the model with respect to the finite element method, selected simulation results are presented

An adapted particle swarm optimization approach for a 2D guillotine cutting stock problem

This paper focuses on the two dimensional rectangular non-oriented guillotine cutting stock problem in which pieces with different dimensions need to be cut with different quantities in order to satisfy customers orders. In order to optimize the raw material utilization, make-to-order and make-to-stock production strategies are combined by considering forecast plans with inventory constraints in addition to firm orders. An adapted version of Particle Swarm Optimization approach is proposed and combined to a hybrid heuristic. Results show that the proposed algorithm outperforms the hybrid heuristic in a reasonable computational time

Control laws synthesis to satisfy generalized mutual exclusion constraints for timed event graphs networks using Min-Plus algebra

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A New Approach to Evaluate and Predict System Obsolescence: Mathematical Formulation

International audienc

Consideration of the uncertainty in the dimensioning of a gearbox of a wind turbine

The paper deals with the design approach of a subdefinite mechatronic system and focuses on the sizing stage of a gearbox of a wind turbine based on the interval computation method. Indeed, gearbox design variables are expressed by intervals to take into account the uncertainty in the estimation of these parameters. The application of the interval computation method allows minimizing the number of simulations and enables obtaining a set of solutions instead of a single one. The dynamic behavior of the gearbox is obtained using the finite element method. The challenge here is to get convergent results with intervals that reflect the efficiency of the applied method. Thus, several mathematical formulations have been tested in static study and evaluated in the case of a truss. Then the interval computation method was used to simulate the behavior of the wind turbine gearbox

Uncertainty of key performance indicators for Industry 4.0: A methodology based on the theory of belief functions

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Le jumeau numérique dans le pilotage de performance

International audienceLa transition vers l'industrie 4.0 est supportée par plusieurs technologies telles que le jumeau numérique. Étant donné qu'il devrait être développé à des fins spécifiques, nous sommes intéressés par l’application du jumeau numérique pour le pilotage de performance.L'objectif de ce papier est d'identifier, à travers un état de l'art, les caractéristiques du jumeau numérique afin de motiver son utilisation pour le pilotage de la performance.Nous indiquons qu'un jumeau numérique d’un atelier de production comprend des jumeaux numériques de produits et de processus capables d'alimenter les systèmes de mesure des performances avec des données pertinentes. Ensuite, nous réalisons une correspondance entre un système de pilotage de performance et un jumeau numérique dans le but de montrer l’utilité de ce dernier. Et nous proposons un ensemble d'utilisations du jumeau numérique dans le pilotage de performance, inspiré des différents défis auxquels sont confrontés les systèmes de pilotage