Evaluation of the effectiveness of the interval computation method to simulate the dynamic behavior of subdefinite system: application on an active suspension system

International audienceA new design approach based on methods by intervals adapted to the integration of the simulation step at the earliest stage of preliminary design for dynamic systems is proposed in this study. The main idea consists on using the interval computation method to make a simulation by intervals in order to minimize the number of simulations which allow obtaining a set of solutions instead of a single one. These intervals represent the domains of possible values for the design parameters of the subdefinite system. So the parameterized model of the system is solved by interval. This avoids launching n simulations with n values for each design parameter. The proposed method is evaluated by several tests on a scalable numerical example. It has been applied to solve parameterized differential equations of a Macpher-son suspension system and to study its dynamic behavior in its passive and active form. The dynamic model of the active suspension is nonlinear but linearisable. It is transformed into a parameterized state equation by intervals. The solution to this state equation is given in the form of a matrix exponential. Three digital implementations of exponential have been tested to obtain convergent results. Simulations results are presented and discussed

Contribution à la prise en compte d'exigences dynamiques en conception préliminaire de systèmes complexes

Cette thèse traite de problématique de dimensionnement d'un système technique complexe. L'objectif est de proposer et d'outiller un processus de conception selon lequel le dimensionnement statique de l'architecture initiale d'un système satisfait dès le début les exigences statiques et dynamiques sans nécessité de redimensionnement. Ainsi, nous avons proposé une nouvelle démarche de conception dans laquelle la prise en compte des exigences statiques et dynamiques est effectuée de maniéré simultanée et globale dans la phase de conception préliminaire. Cette démarche se base sur les exigences pour déterminer les solutions admissibles et utilise des méthodes de résolution ensemblistes telles que la méthode de calcul par intervalle et la méthode de propagation par contraintes. En effet, les variables de conception sont exprimées par intervalles et les exigences statiques et dynamiques sont implémentées dans un même modèle NCSP. Les exigences dynamiques sont plus difficiles à intégrer. Il s'agit des exigences fonctionnelles du système, de la résonance et des critères de stabilité, de commandabilité et de transmittance. Dans un premier temps, nous avons réussi à intégrer le comportement dynamique d'un système technique sous forme d'équation différentielle ordinaire par intervalles et dans un deuxième temps, nous avons traduit les exigences dynamiques sous forme de contraintes algébriques définies par un ensemble d'équations et inéquations. La solution générée représente les valeurs admissibles des variables de conception satisfaisant simultanément les exigences statiques et dynamiques imposées. Ce couplage entre le dimensionnement statique et dynamique dans l'approche de conception proposée permet d'éviter le sur-dimensionnement puisque les exigences dynamiques interviennent dans le choix des coefficients de sécurité, et d'éviter les boucles de redimensionnement en cas d'échec ce qui permet de gagner en temps de calcul et de réduire le coût de conception. La démarche de conception proposée est validée par application sur le cas de dimensionnement d'un système de suspension active MacPherson.This thesis deals with design problems of a complex technical system. The objective is to find a design process which the static design of the initial architecture of a system meets from the first static and dynamic requirements with no need to resize it. Thus, we propose a new design approach which the consideration of static and dynamic requirements is done simultaneously and globally in the preliminary design phase. This approach is based on the requirements to determine admissible solutions and uses set-based methods such as interval computation and constraint propagation. Indeed, the design variables are expressed by intervals and the static and dynamic requirements are implemented in a NCSP model. The dynamic requirements are more difficult to integrate. They represent the functional requirements of the system, the resonance and stability criteria, controllability and transmittance. On the one hand, we succeed to integrate the dynamic behavior of a technical system in the form of ordinary differential equation by intervals. On the other hand, we formalize the dynamic requirements in the form of algebraic constraints defined by a set of equations and inequalities. The generated solution is the set of acceptable values of design variables satisfying simultaneously static and dynamic requirements. This coupling between the static and dynamic sizing steps in the proposed design approach avoids over- sizing of the system as the dynamic requirements involved in the choice of safety factors. Il also avoid resizing loops in case of failure, which saves significant computation time and reduce the cost of design. The proposed design approach is applied on the sizing of a MacPherson active suspension system.CHATENAY MALABRY-Ecole centrale (920192301) / SudocSudocFranceF

Optimisation multicritère de composants mécaniques à l’aide d’une approche par satisfaction de contraintes

Nous proposons d’examiner les apports des techniques de programmation par contrainte en conception et notamment en optimisation de composants mécaniques. Nous présentons le cadre théorique de modélisation d’un problème de satisfaction de contraintes, les principes de résolution et de recherche d’optimum ainsi que leur utilisation potentielle en ingénierie de produit. Un exemple concret d’application au dimensionnement optimal d’une transmission de puissance par adhérence est finalement traité

Set-based design by simulation of usage scenario coverage

While the marketing literature has advocated for decades that new products should be designed for intended and anticipated consumer usages, the engineering literature mostly proposes optimization of product performances independent of specific users’ skills, anticipated usage scenarios, and competing products on the market. In contrast to tedious market studies which assume an existing market experience for products and optimization approaches based upon static product performances, we propose an adaptable approach to designing a product or product family: the set-based design by usage coverage simulation. It starts with generating a usage scenario space for a set of representative users. Next, considering a candidate set of products, one proceeds to the CSP computations of feasible usage scenarios, assuming that physics-based models of performances are available. The comparison between the expected and feasible usage scenarios at the scale of a single user leads to Usage Coverage Indicators and finally to a preferred product which best covers the usage scenario space. At the level of a targeted consumer group, the approach provides a market share simulation for competing products or members of a scale-based product family. The design of a family of jigsaws thoroughly illustrates our approach.Keywords: Set-based design, Usage context based design, Usage coverage metrics, Simulation under uncertainty, Constraint Satisfaction Proble

Towards a correct by construction design of complex systems: The MBSS approach

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Contraintes, objets et ontologies pour la conception de systèmes complexes

International audienc

Interval computation and constraint propagation based optimization approach: Application to active vibration isolation

International audienc

Managing design change order in a PLM platform using a CSP approach

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A CSP approach for managing Design Change Order in a PLM platform

International audienc