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In the animal kingdom, many mammals are using their tails to assure their stability while running, jumping, falling, etc. Researches have been performed in order to add tails on wheeled or legged robots in order to improve their stability. However, those tails are often far from the biological structure and resumed to a simple rigid tube with a mass on the extremity. On the other hand the biological tail is composed of many bones moving one on the other and actuated with an important number of muscles. Therefore replicating this structure would result in big and heavy systems using many actuators that would reduce the physical performances of the robot. In this paper, we developed a new bio-inspired cable-driven tail system capable of swinging a flexible tail from base to tip around the pitching axis using a single actuator. First we designed a new flexible tail mimicking the structure of the animal tail. Then we developed a new actuation system using the combination of cams and drive wheels to realize the actuation of 8 cables using a single actuator. Finally, we measured the efforts generated by the swinging motion of the tail and perform experiments to observe its effects on the jumping motion.

Over the last years, computer-aided design (CAD) has developed rapidly thanks to integrated applications. These applications, namely CAD-integrated applications, have the ability to resolve many industrial challenges related to the design process such as assembly/disassembly sequence planning or computer-aided process planning. The implementation of these applications depends essentially on data extracted from the CAD model. However, the accessibility to these data remains a complex task for CAD-integrated application developers. The aim of this work is modelling and implementing a CAD-integrated system named CADLAB $$^{\copyright }$$ which automatically identifies and generates a diversity of data from a CAD assembly model under exploitable forms. The modelling of this system is performed using MBSE tool which is systems modelling language. The computer implementation of CADLAB is carried out with several software packages such as Solidworks $$^{\copyright }$$ , Excel $$^{\copyright }$$ and MATLAB $$^{\copyright }$$ . With CADLAB system, the identifiable CAD data are the assembly components and constraints’ data. Whereas, the generated CAD data represent the assembly interference matrices as well as several assembly related matrices. The developed system was tested on several CAD examples and the obtained results were verified. The correctness of these results proves the efficiency of CADLAB to carry out CAD data extraction and then enhance the interoperability process between CAD system and CAE applications. The proposed method can help designers find the CAD assembly data in complex mechanical assembly model, facilitate the structuring of the useful designing data, and thereby improve the efficiency of product knowledge reuse.

International audience

International audience; In this paper we study the feedback linearization of multi-input control-affine systems via a particular class of nonregu-lar feedback transformations. We give a complete geometric characterization of systems that become static feedback linearizable after a one-fold reduction of a suitably chosen control. That problem can be seen as the dual of the linearization via invertible one-fold prolongation of a suitably chosen control (which is the simplest dynamic feedback). We discuss in detail similarities and differences of both problems. We propose necessary and sufficient conditions describing the class of systems linearizable via a one-fold reduction, and discuss when the proposed conditions can be verified (by differentiation and algebraic operations only). We provide a normal form and illustrate our results by several examples.

International audience; In this paper, we study the input-output decoupling and linearization of nonlinear two-input two-output time-varying delay systems. When working with delay systems, two problems may arise when constructing a feedback transformation for which the input-output map of the feedback modified systems is linear. The first issue is the boundedness of the control and the second one is its causality. We develop an algorithm allowing the construction of a causal and bounded feedback which permits to solve the input-output decoupling and linearization problem. The idea of our algorithm is to introduce, at each step, when the input-output decoupling is not possible, an artificial delay for the input that appears " too early " in the system. To that end, we propose, at each step, a precise procedure for defining a simple feedback transformation.

International audience; This chapter deals with the damping caused by friction in joints. A new test bench is presented and justified by comparisons made with devices described in the literature. The purpose of this academic bench is to measure the damping induced by partial slip and friction in a planar joint. A new method for the so-called stopped-sine excitation was developed. It allows more precise monitoring of the evolution of the vibration frequency and damping of nonlinear modes, and it allows uncoupling normal static and dynamic tangential forces. This method is associated with piezoelectric exciters for greater efficiency when stopping excitation. A large number of experimental results are presented and discussed, which are used to characterize the damping induced by micro-sliding in the bonds.

International audience; In this work, the unknown cyber-attacks on cyberphysicalsystems are reconstructed using sliding modedifferentiation techniques in concert with the sparse recoveryalgorithm, when only several unknown attacks out of a long listof possible attacks are considered non-zero. The approach isapplied to a model of the electric power system, and finally, theefficacy of the proposed techniques is illustrated via simulationsof a real electric power system.

This thesis deals with the study of themechanical behavior of a conveyor belt underhydrothermal effects. The structure that hasbeen studied consists of a 4 textile layers boundtogether by a thin rubber adhesive layer andcovered with the rubber cover. The beltcomposite structural was characterized usingstandard specimens with and without rubberlayers under tensile and ageing tests. Impacttests are developed to identify the differentdamage modes using microscopic observations..Experimental study of reparation method waselaborated using two processes: hotvulcanization and cold polymerization. Twoone-dimensional and bidirectional analyticmodels are developed and compared with finiteelement models to study the hygrothermomechanicalbehavior of the belt usingexperimental characterization parameters. Theresults showed that the performance ofreparation method of the belt depends ondifferent parameters. A tool for improvementand designing of the reparation is proposedtaking into account these parameters, Cette thèse porte sur l’étude du comportementdes bandes de convoyeurs soumisesà des contraintes mécanique, thermique et hydrique.La bande est constituée par un renforttextile multi-plis incorporé dans deux couchesde revêtement en caoutchouc. Le matériau dela bande en composite structural a été caractériséexpérimentalement à l'aide des essais mécaniqueset hydriques sur des éprouvettes normaliséesen composites avec et sans couche decaoutchouc. Des essais d’impact sont élaborésà fin d’identifier les différents modesd’endommagement à l’aide des observationsmicroscopiques.Une étude expérimentale est élaborée sur laméthode de réparation de la bande par collagede patchs internes en utilisant deux procédés decollage : la polymérisation à froid et la vulcanisationà chaud. Deux modèles analytiques unidimensionnelet bidirectionnel sont développéset confrontés aux modèles par éléments finispour étudier le comportement hygrothermomécaniquede la bande à l’aide des donnéesde caractérisation expérimentale. Les résultatsont montré que les performances de laméthode de réparation dépendent de différentsparamètres hygro-thermomécaniques et géométriques.Un outil d’aide à l’amélioration et à laconception en tenant compte de ces paramètresest enfin proposé.

International audience; La conception optimale des machines élec-triques constitue un défi important et actuel. Dans ce cadre, ce papier présente des travaux de recherche sur le cas d'un moteur brushless. Le problème de conception corres-pondant est particulièrement intéressant car il nécessite à la fois un choix d'architecture et de composants, et un dimensionnement de ces derniers. Dans ce papier, des outils de synthèse acausaux ensemblistes (programmation par contraintes + calcul par intervalles) sont utilisés. L'analyse causale permet en particulier de définir la vraie dimension du problème de conception (« vrais » degrés de liberté) et de mettre en avant l'importance de la stratégie de résolution associée au problème d'optimisation correspondant. Les résultats obtenus sont analysés et comparés aux résultats de la littérature. La méthode proposée permet de trouver des solutions meilleures, montrant ainsi sa pertinence et son efficacité.

Part 8: Knowledge Management and Information Sharing; International audience; Creativity stage or ideation phase is one of the most important step of innovation process where ideas with high potential of environmental and social impact reduction are generated. Therefore, many eco-ideation tools (stimuli, mechanisms, etc.) have been proposed. These tools are mainly at micro level (providing technical solutions) or at macro-level (providing a systemic view). The research project ALIENNOR ( http://www.agence-nationale-recherche.fr/Project-ANR-15-CE10-0001 ) aims at providing a set of Eco-Ideation Stimulation Mechanisms (ESMs) at meso-level compromising both systemic vision and technical solutions. This paper presents how ALIENNOR platform (a part of ALIENNOR project) supports the identification of appropriate ESMs used in eco-ideation phase.

International audience

International audience; In this paper, we consider a nonconvex differential inclusion with constant delay. We study the existence of viable solutions when the state is constrained to the closure of an open subset of R n. The main contribution is a relaxation result stating that, under some assumptions, each "viable solution" of the convexified inclusion can be approximated by "viable solutions" of the original one. This result is obtained thanks to an extension of the celebrated Filippov's theorem to the case of delay differential inclusions.

International audience

International audience; In this paper, we investigate the stabilization of a Lipschitz non linear plant under the assumption of dynamic event triggered sampling. Sufficient conditions, making use of a hybrid Lyapunov function and convex embedding, are given to guarantee the existence of a triggering mechanism, leading to asymptotic stability. Both gain analysis and gain synthesis are considered.

International audience; Many cities around the world have adopted Bike Sharing Systems to offer an alternative to personal vehicles and classic public transport. These systems present many challenges. One of those challenges is the availability of both bikes and docking stations, which has a direct influence on the user satisfaction level. Operator of such a system uses a vehicle fleet dedicated to the repositioning of bikes from full stations to empty ones. This operation, often performed during the night when the demand is negligible, is referred in the literature as static rebalancing. The problem consists in determining the number of bikes to pickup and/or deliver at each station, in order to increase, or even optimize, the availabilities of both bikes and docking stations. The models proposed in the literature are generally linear programming models, which may be hard to establish without proper knowledge of mathematical programming techniques. In this paper, we propose a method for helping the building of these mathematical models through the use of UML graphical class diagrams which describe the structure and properties of a bike sharing system. Transformation rules are defined to extract some constraints of the problem from the system class diagram. The mathematical model is then completed by adding additional constraints as well as the objective function that cannot be expressed in UML language. We will use the case of the Parisian bike sharing system (Vélib’) to illustrate the method.

International audience; We are here interested in the numerical prediction using commercial finite element computation code of the response of large engineering structures made of ductile materials when submitted to accidental overloads. The challenge consists in reproducing within a unified methodology based on the finite element method (FEM) the different steps of failure as observed in the materials under consideration, namely diffuse microvoiding-induced damage, strain/damage localization then macro-cracking, if any. The behavior of the material in presence of ductile damage is governed by the microporous plasticity Gurson model in the context of standard FEM and the kinematic consequences of the macro-crack propagation throughout the meshing are described in the context of the eXtended FEM (XFEM), see Crété et al. (2014). A key point for the prediction of ductile fracture is the numerical treatment of the continuous-to-discontinuous transition, intermediate stage, i.e. localization within a narrow band. To describe it, a model of 'cohesive strong discontinuity' and the XFEM are combined. Criteria for the (more or less) diffuse-damage-to-localization and localization-to-macro-cracking transitions are as well proposed. The feasibility of the methodology has been shown, see Wolf et al. (2017), via the implementation of user element subroutines into the commercial finite element computation code Abaqus, and boundary value problems are solved. J.-P. Crété, P. Longère and J.-M. Cadou, 2014, Numerical modelling of crack propagation in ductile materials combining the GTN model and X-FEM, Comp. Meth. Appl. Mech. Eng. 275, 204-233. J. Wolf, P. Longère, J.-M. Cadou and J.-P. Crété, 2017, Numerical modeling of strain localization in engineering ductile materials combining cohesive models and X-FEM, Int. J. Mech. Mat. Design. In press.

The abrasive water jet (AWJ) cutting technique is one the most rapidly improving technological methods of cutting materials. In this cutting technique, a thin, high velocity water jet accelerates abrasive particles that are directed through an abrasive water jet nozzle at the material to be cut.

Nano-silica and Graphene have been used as the main reinforcing fillers that increase the usefulness of recycled rubber composite. As each filler retains its specific advantages, the use of nano-silica/graphene combinations should improve the mechanical and dynamic properties of recycled rubber composite. But, the optimum nano-silica/graphene ratio giving rise to the optimum properties requests to be explained. In this work, reinforcement of recycled rubber composite with nano-silica/graphene hybrid filler at various ratios was studied in order to determine the optimum nano-silica/graphene combinations. The toughness properties and tribological behaviour indicating the reinforcement of recycled rubber based composite were evaluated. Microstructural and fractural analyses were made by Scanning Electron Microscopy (SEM).

The present paper discusses response surface methodology as an efficient approach for predictive model building and optimization of the high energy milling process from the chip duplex stainless steel with a carbide vanadium addition willing to obtain the smaller particle size. The process parameters studied was milling time of 10 h and 50 h. Rotations were performed at 250 and 350 rpm. Vanadium carbide was added from 0% to 3% in weight, and a mass/ball ratio of 1/10 and 1/20. An analysis of particle size and a scanning electronic microscopy were used to measure and characterize particle size. With addition of carbide in milling process resulted on a reduction of particle size compared to the material without carbide added around 66%. The results predicted using factorial regression model showed high values of regression coefficients (R2 = 0.952) indicating good agreement with experimental data. The minimum value of particle size was obtained for following optimal conditions: rotation of 325 rpm, time of 42 h, ball/mass 18:1 and carbide 2, 67%wt. The particle size of fabricated powders after 50 h of milling with 3% vanadium carbide addition was about 186 times lower than that the initial chips.

Environmental and economic concerns has been a motivation for the material manufacturers to produce new, robust, lightweight and cost-effective materials. Therefore, aeronautic and automobile industries are investigating multifunctional composite materials that can meet their expectations. In this regard, polymer based composites can have high specific strength with the contribution of resistant fillers. As a polymer, epoxy is considered an appropriate matrix, which can be modified by different agents. First option is the addition of hard particles and second is that the inclusion of thermoplastics or the addition of elastomeric materials. Since, epoxy exhibits high brittleness due to its highly cross-linked nature, modifiers less rigid than the matrix can serve as unique tougheners enhancing the ductility. In this study, a good combination of both hard and soft modifiers is used. In addition to mechanical characteristics, using of fresh clean scrap EPDM rubbers adds an economic and environmental value to this study. Also, due to its favorable structural characteristics such as interlocking effects of fibers, addition of alumina fibers (AF) ensures desired mechanical properties in case of a homogeneous distribution. This paper primarily explains the mechanical behavior as well as damage mechanisms of epoxy-fresh scrap rubber composites. The mechanical and physical properties of these composite systems are studied in the present work. Dynamic Mechanical Analysis (DMA) analyses were carried out to determine thermal-mechanical properties. Three-point bending and fracture toughness tests were realized with single edge notched beam (SENB) and smooth specimens. Finally, scanning electron microscope (SEM) was used to observe fracture surfaces and the microstructure.

In this work, an alternative aluminum matrix composite (AMCs) was designed from the recycled chips of the aluminium series of AA7075 (90 wt %) and AA1050 (10 wt %) given by French aeronautic company through combined method of powder metallurgy followed by Sintering + Forging. We aimed for the application for the connection link in a mechanism to transfer motion, for example; between the two railways wagons etc. and also some connecting link in aeronautical pieces as an alternative replacement for conventional alloys used in this area. First of all, A typical Al-Zn-Mg-Si-Ni matrix was developed and reinforced basically with B2O3 (5, 10%). Chip milling was performed using high energy milling in a planetary ball mill with an inert argon atmosphere to prevent oxidation of the powders. Two compositions were prepared with two different percentages of B2O3 and also one composition was kept without reinforcement for comparison with the reinforced ones. Mechanical properties, compression and dynamic drop weight tests of these composites designed here can be improved with the doping process and doping volume fractions. Micro-hardness results were compared according to the optimization conditions of the doping and the reinforcement. Static compression and impact-drop weight tests were carried out. The microstructure analyses have been carried out by Scanning Electron Microscope (SEM).

In the present work, a recycled copper based composites reinforced with ceramic as an alternative replacement for the application of electric motor repair parts with the use of novel processing techniques.

Recycling is a subject undergoing intense study in terms of sustainable development. In every area, recycling is strongly encouraged by governments due to the international agreements on environmental issues. For example, many industrial manufacturers have a tendency to find clean and cost-efficient solutions by utilizing recycled materials to produce new components. In this regard, rubbers have very wide usage in aeronautic and automotive industries both in structural and in interior body components. Rubbers are also used to modify brittle polymer components in the existence of hard, resistant fillers. In this study, fresh scrap EPDM rubbers are used to manufacture novel composites by modifying epoxy resin with the inclusion of graphene nano platelets (GnPs). Rather than micro sized particles, nanoparticles have high surface area, which means that a low content of these nanoparticles may enhance the material’s properties more efficiently. Besides, due to its superior structural, thermal and physical characteristics, addition of graphene promises improved mechanical properties if they can be dispersed homogeneously. This paper is focused on the fracture characteristics and toughening mechanisms of epoxy – fresh scrap rubber composites. The mechanical and physical properties of these composite systems are studied in the present work. Mechanical properties are examined by means of three-point bending tests with smooth and single edge notched beam specimens (SENB). Also, nano indentation tests were realized to see the creep compliance and viscoelastic properties. Finally, scanning electron microscope (SEM) was used to observe the fracture surfaces and the microstructure.

Titanium and its alloys have over the years proven themselves to be technically superior and cost effective materials for a wide range of applications spanning the industries of aerospace, industrial, marine, and even commercial products. In this paper, the surface integrity of titanium alloys Ti-6Al-4V and pure titanium Ti, cut with high power CO2 laser is determined and the results are presented and discussed. The aim of this experimental investigation is to compare the microstructure and the cut surface quality of both titanium based on the variation of three different cutting parameters namely, laser power (Pu), cutting speed (V) and gas pressure (p).

New classes of aluminium matrix composites (AMCs – 356) were designed by three different manufacturing techniques; only sintering, through combined method called here after “Sinter + Forging” and/or “sinter + thixoforming”. Main reinforcement was magnetic iron oxide, Fe3O4 (10, 20 and 30 wt %) and two recycled reinforcements, nickel, Ni and pure electrolytic copper, Cu, given by French Aeronautical Society were also used and preceded under the constant process parameters such as hot compaction, sinter-forging, sintering time, Forging temperature and Force, etc. As auxiliary element, hybrid graphene nano-platelets, GNPs, was added in the structure. Microstructural analyses (by using SEM), magnetic, mechanical and physical properties of the composites were compared with three different manufacturing processes. Static compression tests, Micro hardness tests, measurement of magnetic permeability and also electrical conductivity, have shown that the mechanical and physical properties of these composites can be improved with the optimization of process parameters. In the present work, an alternative and a low cost manufacturing process were proposed for these composites.

In last decades, aerospace and automotive industries are in search of multi-functional high performance, low cost materials due to certain environmental regulations. Epoxy-recycled rubber based structural composites (ERCs) are used in these type of engineering applications thanks to their favorable properties such as corrosion resistance, low cost and light weight. In addition, the use of recycled materials gives an economic and environmental aspect to the manufacturers. The data for basic material parameters of these composites is essential in order to realize an efficient engineering development process. For this reason, this paper is focused on the design of ERCs reinforced with ceramic powders in different ratios in a matrix of epoxy-fresh scrap rubber. The mechanical and some physical properties of these composite systems were studied in this research. Titanium dioxide (titania-TiO2) and alumina fibers (Al2O3) are used as reinforcements in pre-defined weight percentages. During this study, mechanical and wear properties of these composite systems are studied. Three-point bending tests and nanoindentation were conducted to evaluate mechanical properties. After that, wear resistance is examined by means of nano-scratch tests. As the final step, fracture surfaces were observed with scanning electron microscopy (SEM) to identify damage mechanisms of these composites.

Graded composites of grade FE50007 nodular ductile iron reinforced with WC granules grinded from recycled cutting tools, were produced by casting, using lost foam technique. Reinforcement granules were forced to be located in a specific region of the part by controlling flow during pouring. Different casting conditions were investigated (reinforcing granules content and dimensions). Resulting microstructures were extensively analysed to investigate eventual phases modifications in the iron matrix among reinforcing particles and interface interactions or possible reactions. Results show that WC granules deteriorates in contact with liquid metal, by diffusion of binder elements, detaching WC individual particles, resulting in a smooth and continuous interface; any kind of reaction is observed in the interface. The presence of the ceramic particles modifies the alloy microstructure within the reinforced region due to thermal and chemical local features. Preliminary studies on wear behaviour for a specific cast product developed (an impact crusher) are also presented, indicated superior performance compared to commercial crushers.

CO2 laser cutting is an advanced processing technology, which can, according to the computer-aided design graphics, cut a variety of shapes in the surfaces of many metallic sheets. Laser cutting of various materials including the Titanium alloy Ti-6Al-4V and pure Titanium Ti is carried out to assess the kerf width size variation along the cut section. This work aims to analyze the effect of laser power, cutting speed, and gas pressure on the kerf quality of Ti-6Al-4V alloy and Ti with CO2 laser cutting process. The kerf width size is formulated and predicted using the lump parameter analysis and it is measured from the experiments. The influence of laser output power Pu and laser cutting speed V and pressure nitrogen assisting gas p on the kerf width size variation is analyzed using the analytical tools including scanning electron and optical microscopes. The quality of laser cut kerf mainly depends on appropriate selection of process parameters. Uniform kerf with minimum kerf width is always demand. It has been found that the kerf width during CO2 laser process is not uniform along the length of cut. A considerable improvement in kerf quality has been achieved.

This study investigate the influence of the machining parameters on Ti-Al intermetallic composite based using a wire electrical discharge machining. This process is typically used for very hard material, which are hard to machine using a more traditional process. The aim of the work is to optimize the integrity of surface of Ti-Al intermetallic composite machined by WEDM. The first step is defined the machining parameters of the process: Start up voltage U, Pulse on time Ton or T, advanced speed S and flushing pressure P (pressure of injection of dielectric) are chosen to determine their effects on surface roughness Ra. The second step is using integrated method, which mixed Taguchi method and response surface methodology RSM, the RSM model was developed as a tool to predict the integrity of surface of Ti-Al intermetallic composite machined by WEDM. The significance of the machining parameters was obtained using analysis of variance (ANOVA) based on S/N ratio, which show that flushing pressure P, Pulse on Time T and Voltage U were the most significant parameters. Microstructure of surface and subsurface, cracks, craters, and debris and roughness surface of the samples machined at the different condition has been realized by scanning electron microscopy (SEM), and 3D-Surfscan. The integrate method of Taguchi and RSM was validated by conducting validation experiment to ensure that it can work accurately as a prediction tool.

In the present work, Copper-Aluminium based composites(CAMCs) were designed through 3 different manufacturing processes; “Sintering, “Sinter + Forging” and also “sinter + thixoforming” was made a pre alloy from pure electrolytic copper that was doped with atomized recycled aluminium alloy chips (AA7075) that was given by French Aeronautical Society. After that, a typical composite was created by adding nano magnetic iron oxide (Fe3O4) with a special treatment. Nb2Al intermetallic was also used as reinforcements to increase the wear resistance of the final structure. Graphene Nano Plates (GNPs) and nickel were also added to the CAMCs structures to improve mechanical behaviour and wear resistance of these novel composites. The addition of hard ceramic and/or intermetallic particles to soft copper matrix can significantly improve the mechanical properties and wear resistance, without any serious deteriorating of both magnetic, thermal and electrical conductivities of copper based composites.

In this paper, we study the integrated scenarios of formation tracking, collision avoidance and obstacle avoidance of multiple unmanned underwater vehicles (UUV). It is assumed that the communication graph is directed and connected. The desired formation shape that is created is maintained and follow the trajectory by the consensus algorithm while the potential function is addressed for a collision avoidance. During following the trajectory, the Bezier curve is used for make a new trajectory to avoid obstacles. The effectiveness of the scenario is verified by a numerical simulation.

International audience; This work is concerned with the numerical simulation of sound pressure field in three-dimensional cavities in which absorbing materials are present. Standard techniques such as the Finite Element Method are known to be extremely demanding computationally when the frequency increases and thus limited to low frequency applications. To alleviate these difficulties, an alternative formulation based on the Partition of Unity Finite Element Method is proposed. The method involves enriching the approximation finite element space by expanding the acoustic pressure in a set of plane waves propagating in various directions over the unit sphere. Particular attention is devoted to the fast and accurate computation of highly oscillatory integrals which is required by the method. Convergence studies show that these wave finite elements allow to capture accurately the wave field with a number of degrees of freedom that only grows quadratically with the frequency yielding drastic data reduction compared to classical FEM. Results of practical interest are shown for the case of a sound source placed in a reverberation room with absorbing materials.

International audience; The users of a B2C Bike Sharing System are satisfied if they find always free bikes and free docks at the stations. Modeling such systems is challenging because they are large-scaled and characterized by their stochastic dynamic. To study the performance of a BSS, we rely on a queuing model solved by the Entropy Maximization. In this paper, we study the possibility of aggregating a number of stations in a single virtual station to reduce the complexity of the model and its resolution. Experiments are performed to qualify impacts of the model reduction on the accuracy of the obtained results.

International audience; Facility Layout Problem (FLP) is to arrange facilities efficiently within the available floor area to operate in an effective way. A good layout design contributes to the overall efficiency of operations. For this reason, in the FLP studies, design rules related to process flow, material handling, space shapes and requirements and communication between workers are taken into consideration. FLP has attracted much attention over last decades. However, as far as we were able to find, there is a lack of a survey that structures the used design rules, objectives functions, constraints and search strategies. In this paper, we aim at providing such study. Accordingly, an overview of the FLP is introduced based on basic features of the problem and resolution methodologies. We propose a new classification of FLP resolution methods according to objectives functions and constraints. Finally, we present an analysis and an assessment of the current and future trends of research in this field.

International audience; The main goals of the demonstrator developed within the FRDISI (Foundation for Research, Development and Innovation in Engineering Sciences) in Casablanca (Morocco) are to allow the development of new concepts and tools in smart-parking management. It will also permit to experiment other smart sensors and parking management analysis algorithms. The demonstrator will offer a platform to develop and experiment innovative solutions for an efficient management of the energy consumption of all the infrastructure and physical equipment of the smart-parking. Through our demonstrator, FRDISI will be able to help drivers, through a web or android application, to reduce parking search time, to make place reservation. This application proposes a lot of innovative functionality among them a reservation system. It will help the parking owners to increase the rotations of their parking spaces (near malls, near airports) which can positively impact the economic profitability of the parking infrastructure. In addition, the demonstrator produces green energy and is energy autonomous. For cities responsible, it proposes steps for the support tools' development in smart-parking and analyze the uses for a better definition of the mobility policy of the city. FRDISI will launch many subjects in applied research domain to improve and develop the know-how in the field, to develop and experiment innovative futurist solutions such as optimization algorithm in the parking rules according to demand (handicap, drop-off, public transport, funds conveyors, neighborhood markets, schools, events, etc.), implementing new sensor technologies and new modes of energy-efficient communication while taking advantage of existing telecommunication infrastructures (Internet of Things IoT Concept). As our platform will encourage the green mobility solutions by providing smart load for electric vehicles.

International audience; The present work tackles the modeling of multi-physics systems applying a topological approach while proceeding with a new methodology using a topological modification to the structure of systems. Then the comparison with the Magos' methodology is made. Their common ground is the use of connectivity within systems. The comparison and analysis of the different types of modeling show the importance of the topological methodology through the integration of the topological modification to the topological structure of a multi-physics system. In order to validate this methodology, the case of Pogo-stick is studied. The first step consists in generating a topological graph of the system. Then the connectivity step takes into account the contact with the ground. During the last step of this research; the MGS language (Modeling of General System) is used to model the system through equations. Finally, the results are compared to those obtained by MODELICA. Therefore, this proposed methodology may be generalized to model multi-physics systems that can be considered as a set of local elements.

This paper presents a new spectral element based on the dynamic stiffness matrix of a prestressed cylindrical shell. The dynamic stiffness matrix is built using first-order shear deformation theory, and natural frequencies are processed easily. Vibration analyses are performed with numerical examples to determine the performance of this approach and the effect of prestressing on frequency response functions. This element has many advantages over the finite element method in terms of accuracy, model size and computing time.

The environmental consequences of mass consumption require to eco-innovate, which means completely rethinking our way of designing, manufacturing and consuming by proposing on the market products and services with a high environmental ambition. In order to help companies in early design phases of eco-innovation, this article investigates the criteria of eco-innovation and tests the understanding of a set of 7 Eco-ideation Stimulation Meso-mechanisms, named ESM. A qualitative experiment based on focus groups and on a case based reasoning approach delivers operable criteria of eco-innovation and redefines at the same time what eco-innovation is. The exhaustive aspect of eco-innovation dimensions to explore covered by the ESM set is confirmed too.

Mechatronics expresses the close integration of mechanics, electrics/electronics, control engineering and software engineering. The design of mechatronic systems follows the traditional point-based design method, which drawback is the decrease of the potential of innovation, by limiting the design space to few solutions. The Set-Based Concurrent Engineering SBCE, however, begins by broadly considering sets of possible solutions and gradually narrowing the set of possibilities to converge on a final solution. Nevertheless, few industrials in the mechatronic field are using SBCE concept, because of the difficulty to implement it. In this paper, we show how to apply the SBCE concept for mechatronic systems, with an application to an industrial case study of an Electronic Throttle Body (ETB), used to regulate the amount of air in an internal combustion engine. The results show that with a well-structured SBCE process model, we can explore the big number of solutions that we generate when dealing with mechatronic systems, and then we progressively reduce the set of possibilities to the final system design.

Problem- and project-based learning approaches place the students at the center of the learning processes and give the opportunity to make the students active and involved. It also prepares the students for their future professional life by placing them in real situations with different stakeholders. The assessments implemented during problem and project phases allow to evaluate the acquisition of disciplinary skills and competences. This kind of teaching and learning also provides the opportunity to develop specific project skills giving more autonomy and agility to the students in complex problem solving. Knowing their level of acquisition of these skills is a key point for the students, making them more confident in face of the problems they have to solve. All these aspects have been widely experienced and are well documented. ISMEP-Supmeca, a French public engineering school, has chosen since decades to engage in problem-and project-based learning. Progressively, this approach developed through various axis, including educational research projects (IDEFI PLACIS, Erasmus+ strategic partnerships EPICES and EBCC). There are now three offers of this kind at ISMEP-Supmeca: one problem-based learning module for first year students, and two project-based learning modules for second and last year students. Moreover, a self-assessment process has been implemented in order to enable the students to self-assess their project mode skills. Students realize one self-assessment at the beginning of the module and one at the end. In the first one, they evaluate their skills before working with others and receiving feedback, whereas in the second one, their assessment results from the experience gained during the module. This paper presents the first results and the perspectives of this self-assessment experiment, which will continue to be developed.

International audience

This work aims to solve the problem of home care rounds using a metaheuristic nature-inspired which is the Firefly Algorithm (FF). A good discretization and correction of the solution has been provided to maintain the advantages of such an algorithm on this combinatorial problem. Even if the problem is only an extension of the classical Time Windowed Vehicle Routing Problem (TWVRP), the human aspect hardens it so that any abuse of constraint may eliminate feasibility or decrease the quality of services. Hard constraints concern the precedence between cares and the synchronization of several cares of the same patient. Whereas soft constraints concern preferences in time windows. The problem in this work also takes into account overtime and the drudgery of home-based workers. The main objective is to minimize the total duration of the tour and maximize the satisfaction of the constraints. After weighting the maximization of the satisfaction of soft constraints and penalizing the abuse of hard constraints, the proposed approach was tested on several data sets. This paper presents two examples containing 20 cares. The tour uses only health care workers of the same skill set. The results show that compared to local search (LS) and particle swarm optimization (PSO), the discrete version of the firefly algorithm gives a better total travel time and better satisfies soft constraints. Keywords-Home Care; Firefly Algorithm (FF); Particle Swarm Optimization (PSO), Local Search (LS); Time Window Vehicle Touring Problem (TWVRP).Translated with www.DeepL.com/Translator (free version), Ce travail vise à résoudre le problème de la tournée de soins à domicile en utilisant une métaheuristique inspirée de la nature qui est l'algorithme de Lucioles ou Firefly Algorithm (FF). Une bonne discrétisation et une bonne correction de la solution ont été fournies pour maintenir les avantages d'un tel algorithme sur ce problème combinatoire. Même si le problème n'est qu'une extension du problème de tournée de véhicules à fenêtres de temps classique (TWVRP), l'aspect humain le durcit de sorte que tout abus de contrainte peut éliminer la faisabilité ou diminuer la qualité des services. Les contraintes dures concernent la précédence entre les soins et la synchronisation de plusieurs soins du même patient. Alors que les contraintes souples concernent les préférences en fenêtres de temps. Le problème dans ce travail prend également en compte les heures supplémentaires et la pénibilité des travailleurs à domicile. L'objectif principal est de minimiser la durée totale de la tournée et de maximiser la satisfaction des contraintes. Après une pondération de la maximisation de la satisfaction des contraintes souples et la pénalisation d'abus de contraintes dures, l'approche proposée a été testée sur plusieurs jeux de données. Ce papier expose deux exemples contenant 20 soins. La tournée utilise seulement des travailleurs de santé de même compétence. Les résultats montrent que par rapport à la recherche locale (LS) et à l'optimisation par essaims de particules (PSO), la version discrète de l'algorithme de lucioles donne un meilleur temps total de trajet et satisfait mieux les contraintes souples. Mots-clés-Soins à domicile ; Firefly Algorithm (FF); Optimisation par essaims de particules (PSO), recherche locale (LS); problème de tournée de véhicules avec fenêtres de temps (TWVRP).

The SMEs, predominant actors of the industry, have to reach customer expectations that are more and more complex. One of the solutions is to improve the management of the industrial processes which includes production planning and control, performance measurement and evaluation. Lately the concept of industry 4.0 has emerged. This new approach allows the control of production processes by providing real time synchronization of flows and by enabling the production of unitary and customized products. This concept is based on emerging new technologies such as cloud computing and Internet of Things. Our research goal is to identify the industry 4.0 risks, opportunities and critical success factors regarding SMEs industrial performances. Our first work shows that the SMEs have their own specific managerial features that may undermine the adoption of the industry 4.0 concept. Our review of the scientific literature also shows that there are disparities between industry 4.0 business cases in SMEs. These business cases are also poorly documented a provide only few insights for SMEs managers. The inherent difficulty to identify detailed examples prevented us from conducting a statistical study of the industry 4.0 cases within SMEs. In order to reach our research goal, we conducted a prospective study by consulting experts. Our study shows that the major risks facing the adoption of the industry 4.0 concept in SMEs is the lack of expertise and the short-term strategy mindset. The study also shows that training is the most important success factor, that managers have a prominent role in the success and/or the failure of an industry 4.0 project, and that SMEs should be supported by external experts. Lastly, industry 4.0 offers a unique opportunity to redesign SMEs production processes and to adopt new business models. SMEs have decisive advantages toward this industrial revolution that they must use in order to keep their competitive advantages against large company.; Acteurs majeurs de l’industrie, les PME (Petites et Moyennes Entreprises) doivent répondre à des exigences toujours plus complexes de leurs clients. L’une des solutions est l’amélioration du pilotage des processus industriels qui comprend la planification et l’exploitation des ressources, le contrôle de la production, la mesure et l’évaluation de la performance. Récemment est né le concept d’industrie 4.0 qui vise au pilotage de la chaîne logistique par la synchronisation en temps réel des flux pour tendre à la fabrication unitaire et personnalisée. Ce concept se base sur l’émergence de nouvelles technologies telles que l’internet des objets et le cloud computing. Notre objectif est d’identifier les risques, les opportunités et les facteurs critiques de succès de l’industrie 4.0 concernant la performance industrielle des PME. Nos premiers travaux montrent que les PME présentent des caractéristiques managériales propres qui peuvent venir à l’encontre des prérequis nécessaires à l’exploitation de l’industrie 4.0. Notre revue de la littérature montre d’une part des disparités dans les cas d’application de l’industrie 4.0 dans les PME, et d’autre part que ces cas sont peu documentés. La difficulté inhérente à l’identification de cas concrets ne nous a pas permis d’organiser une étude statistique de l’application de l’industrie 4.0. Afin de répondre à nos objectifs, nous avons ainsi organisé une étude prospective par consultation d’experts. Cette étude a montré que le manque d’expertise et la stratégie à courte vue sont les risques les plus importants de l’industrie 4.0 dans les PME. L’étude montre également que la formation est le facteur de réussite le plus important, que le dirigeant joue un rôle prépondérant dans la réussite et/ou l’échec d’un projet industrie 4.0 et qu’il est conseillé de se faire accompagner par des experts pour tout projet d’industrie 4.0. Enfin, l’industrie 4.0 est une opportunité exceptionnelle de repenser les processus de production, mais également de proposer de nouveaux modèles d’affaires pour les PME. Les PME présentent des atouts majeurs face à cette révolution industrielle et elles doivent en tirer profit pour ne pas perdre leur avantage concurrentiel vis-à-vis des grandes entreprises.

One-off or Batch upgrading is the term given to the process of improving one or several operational instances of complex products or systems (e.g., trains, aircrafts, etc.) during their life span. Other products such as cars or personal computers are regularly improved through redesign, generation after generation; however, redesign never concerns only one or several instance(s). The main challenge presented in this paper is to provide a suitable framework to analyse one-off and batch upgrading processes. This framework targets at containing required concepts and drivers for upgrade problem posing. The axiom beneath this research is that the goal of upgradings is to improve the performances of products or systems. Upgrade-to-performance, UtP in short, represents this paradigm that will be defined and illustrated through examples. To reach this goal, necessary concepts are defined and linked together through a generic data model. The UtP data model can be used in a conceptual way clarifying the scope of the upgrading process. It can also be specialized to specific industrial domain and used as the main driver of the design of a database for a given upgrading projects. The use case reported concerns the conversion of a passenger train into an express freight where the focus is put on enlarging a coach’ door. The results are then discussed to figure out the links between the UtP problem-posing and problem-solving methods and the gaps to fill. Finally, further research niches are described.

In order to manage quality, companies need to predict performance variations of products due to the manufacturing components deviations. Usually, to enable the assembly of overconstrained mechanical structure, engineers introduce clearance inside joints. We call mechanical assembly, a set of undeformable components connected together by mechanical joints. This paper presents a solution: firstly, to compute the minimum value of clearance for any given components sizes, and, secondly, to simulate variation of the minimum clearance value when the components dimensions vary between two limits. To achieve this goal, a regularized closure function G is defined. It depends on dimensional parameters, u , representing components dimensions, on positional parameters, p , representing components positions and on clearance parameters, j , representing mechanical joints clearance. A constrained optimization problem is solved to determine the minimum clearance value. An imaginative solution based on numerical integration of an ordinary differential equation is proposed to show the clearance variation. The method is designed to be used during the preliminary phase of overconstrained assemblies design. An advantage is the small number of input data unlike the tolerance analysis dedicated software.

International audience; Due to the manufacturing process, some fibrous materials like glasswool may be transversely isotropic (TI): fibers are mostly parallel to a plane of isotropy within which material properties are identical in all directions whereas properties are different along the transverse direction. The behavior of TI fibrous material is well described by the TI Biot's model, but it requires to measure several mechanical parameters and to solve the TI Biot's equations. This paper presents an equivalent fluid model that can be suitable for TI materials under certain assumptions. It takes the form of a classical wave equation for the pressure involving an effective density tensor combining both limp and rigid frame behaviors of the material. This scalar wave equation is easily amenable to analytical and numerical treatments with finite element method. Numerical results, based on the proposed model, are compared with experimental results obtained for two configurations with a fibrous material. The first concerns the absorption of an incident plane wave impinging on a fibrous slab and the second corresponds to the transmission loss of a splitter-type silencer in a duct. Both configurations highlight the effect of the sample orientation and give an illustration of the unusual TI behavior for fluids.

International audience; In this paper we investigate the left invertibility problem for a class of nonlinear time-delay systems. In both cases of time delay systems with and without internal dynamics the invertibility conditions are given. A new approach based on the use of higher order sliding mode observer is developed for finite-time left invertibility and for asymptotic left inversion. Causal and non-causal estimation of the unknown inputs are respectively discussed. The results are illustrated by numerical examples in order to show the efficiency of the method and its limits.

International audience

International audience

International audience; The paper presents two new methods for engineering change propagation. These methods evaluate the product change impact and predict the change propagation effect. The two change propagation methods (i) Layer propagation method and (ii) Path propagation method, are applied to the dependency graph and based on the Depth First Search and the Breadth First Search algorithms. The dependency graph links two product parameters with their functional dependency. By using these two methods, designers can better understand the direct change impact by product parameters interactions and the indirect change effect via the propagation.