User-Driven Computer-Assisted Reverse Engineering of Editable CAD Assembly Models

Authors : SHAH, Ghazanfar Ali POLETTE, Arnaud PERNOT, Jean-Philippe GIANNINI, Franca MONTI, Marina
Publisher : ASME
This paper introduces a novel reverse engineering (RE) technique for the reconstruction of editable computer-aided design (CAD) models of mechanical parts’ assemblies. The input is a point cloud of a mechanical parts’ assembly that has been acquired as a whole, i.e., without disassembling it prior to its digitization. The proposed framework allows for the reconstruction of the parametric CAD assembly model through a multi-step reconstruction and fitting approach. It is modular and it supports various exploitation scenarios depending on the available data and starting point. It also handles incomplete datasets. The reconstruction process starts from roughly sketched and parameterized CAD geometries (i.e., 2D sketches, 3D parts, or assemblies) that are then used as input of a simulated annealing-based fitting algorithm, which minimizes the deviation between the point cloud and the adapted geometries. The coherence of the CAD models is maintained by a CAD modeler that performs the geometries’ updates while guaranteeing the possibly imposed constraints and model coherence. The optimization process leverages a two-level filtering technique able to capture and manage the boundaries of the geometries inside the overall point cloud in order to allow local fitting and interfaces detection. It is a user-driven approach where the user decides what are the most suitable steps and sequence to operate. It has been tested and validated on both real scanned point clouds and as-scanned virtually generated point clouds incorporating several artifacts that would appear with real acquisition devices.

Développement d’un jumeau numérique pour le pilotage en énergie d’une opération de forgeage

Authors : URIBE, David DURAND, Camille BAUDOUIN, Cyrille BIGOT, Régis KRUMPIPE, Pierre
Publisher : CIFORGE
Depuis plusieurs années, les processus de fabrication sont progressivement automatisés pour améliorer leur répétabilité et leur reproductibilité. Parallèlement, des optimisations sont apportées afin d’améliorer la robustesse des procédés, pour limiter l’impact des variabilités des paramètres du processus sur la qualité finale de la pièce. Sur des petites séries, comme cela est le cas dans le secteur aéronautique par exemple, cette démarche d’automatisation et d’amélioration de la robustesse n’est pas nécessairement rentable. En effet, même si les gammes sont rigoureusement préparées en bureau des méthodes, la production reste majoritairement tributaire du savoir-faire des opérateurs. Pourtant, les accréditations qualité comme NADCAP (National Aerospace and Defense Contractors Accreditation Program) demandent à tracer le respect des procédures. Or cette demande de traçage qualité est peu compatible avec un processus où les prises de décision de l’opérateur jouent un rôle majeur. Ces dernières années, avec l’apparition des concepts de l’usine du futur (tels que la personnalisation de masse, la robotisation des procédés, l’acquisition et le traitement d’un grand nombre d’informations, le développement des jumeaux numériques, etc.), l’enjeu est de pouvoir apporter de la flexibilité et de la robustesse particulièrement adaptées à la petite série. Dans ce contexte, le Laboratoire de Conception – Fabrication – Commande (LCFC) à Metz, avec son partenaire le CETIM, dans le cadre du laboratoire commun, le Laboratoire de Mise en Forme des Matériaux (LaMFM) ont, entre autres, pour préoccupation d’industrialiser ces concepts dans les entreprises de forge et de mise en forme de la matière. Dans ce cadre, un projet de thèse sur la création d’un jumeau numérique pour le pilotage d’une opération de forgeage en énergie a démarré en octobre 2021.

Collective Intelligence Application in a Kitting Picking Zone of the Automotive Industry

Authors : MONTOYA ZAPATA, Santiago KLEMENT, Nathalie SILVA, Cristovão GIBARU, Olivier LAFOU, Meriem
Publisher : Springer International Publishing
The durability of an automobile factory depends on its flexibility and its evolution capacity to meet market expectations. These expectations tend increasingly to the vehicles’ customization. Therefore, automobile factories may be able to manufacture several vehicle models on the same assembly line. It makes automobile manufacturers face big logistic challenges in their production sites. They must be capable of simplifying, synchronizing and proposing intelligent and flexible logistic flow. Thus, digital tools for decision support are needed. This paper aims to propose an architecture to model the logistic process of supplying materials to the assembly line as a multia-gent system. Thus, multiagent learning and collective intelligence techniques can be applied to guarantee a good performance of the process. The case study focuses on a kitting picking zone from a Renault production site which manufactures six different vehicle models, each one with its variants.

Economic and ergonomic performance enhancement in assembly process through multiple collaboration modes between human and robot

Authors : QUENEHEN, Anthony KLEMENT, Nathalie ABDELJAOUAD, Amine Mohamed ROUCOULES, Lionel GIBARU, Olivier
Publisher : Informa UK Limited
Collaborative robots have open new ways of designing assembly processes, thanks to their ability to share work space with operators. not only may they support the economical performance, but they can also improve the overall ergonomics. Building on existing work on task allocation problems, the authors study further the collaboration opportunities between operator and robot, namely cooperation phases (type of collaboration where both operator and robot act on the same work piece). This work proposes anewformulation of the related problem, and solutions are sought through heuristics methods, to investigate whether concurrent usage of different collaboration modes delivers better performance. The results indicate that cooperation mode enables higher process performances while controlling ergonomic risks. With a concern for real-life application, it has been applied on a real case study to verify its applicability.

Moving Towards a Sustainable Model: Societal, Economic and Environmental

Authors : MARTIN, Patrick NOUIRI, Maroua SIADAT, Ali
Publisher : Wiley
Sustainable development is a concept of development that meets the needs of the present without compromising the ability to meet the needs of future generations. A sustainable model must therefore ensure a balance between economic, environmental and social impacts. This chapter examines how industrial cyber-physical systems (ICPS) have characteristics that contribute to solving these sustainable development challenges. The advantages of ICPS in favor of humans will be found in the different categories of aspects: the cognitive aspects, and the occupational health and safety aspects. The concept of ICPS is relevant to reduce environmental impacts within the industrial environment. Indeed, the cyber layer makes it possible to retrieve data in real time and extract useful information in the environmental component. Because of their ability to adapt quickly, optimize and integrate the various information systems, ICPS clearly contribute to the economic dimension of companies.

A thermal resistant and flame retardant separator reinforced by attapulgite for lithium-ion batteries via multilayer coextrusion

Authors : LI, Yajie YANG, Haicun AHMADI-SENICHAULT, Azita OMARI, Aziz PU, Hongting
Publisher : Elsevier BV
Multilayer separators are widely used due to their wide shutdown window by combining lower melting tem- perature and higher melting temperature of different layers. With the development of high power lithium-ion batteries, multilayer separators equipped with effective thermal stability and flame retardancy are highly required. Herein, the poly(methyl methacrylate) modified attapulgite (ATPM) is selected as the heat resistant reinforcing component and blended with polypropylene (PP)/polyethylene (PE) respectively. Then we prepare PP(ATPM)/PE(ATPM) separators via multilayer coextrusion efficiently without multiple stretching processes, which can avoid serious separator shrinkage at elevated temperature. The intertwined ATPM could not only enhance the separator integrity, but also produce water vapor and oxide anti-flaming isolation layers at high temperatures. The as-prepared separators, referred to as MC-TIPS PP/PE/ATPM, exhibit higher thermal stability (with negligible dimensional shrinkage up to 180 ◦C), better flame retardancy and wider shutdown temperature window (124–183 ◦C) than the commercial multilayer separators. Moreover, the introduction of ester and hydroxyl groups could improve the wettability and electrolyte uptake of the separators. These properties, as well as the potential for large-scale production of multilayer coextrusion, make MC-TIPS PP/PE/ATPM an ideal choice for high-power battery separators.

Sim-optimization hybrid approach for scheduling randomly deteriorating treatment tasks in horticulture

Authors : MAZAR, Merouane BETTAYEB, Belgacem KLEMENT, Nathalie SAHNOUN, Mhammed LOUIS, Anne
Publisher : Elsevier BV
In this paper, we study the problem of scheduling robotized tasks in the context of Agriculture 4.0. The objective is to optimize the treatment tasks of plants against an evolving disease (mildew) within a greenhouse. The treatment is performed using a type-C ultraviolet radiation (UV-C) by an UV-Robot. We propose a semi-dynamic simulation-optimization approach based on a Markovian model of the disease behavior in the greenhouse. Two variants of simulation-optimization hybridization are tested and analyed.

Impact of Industrial Cyber‐Physical Systems on Reconfigurable Manufacturing Systems

Authors : DA CUNHA, Catherine KLEMENT, Nathalie
Publisher : Wiley
Production systems adapt to market changes and integrate technical and social progress. These systems are therefore now qualified as reconfigurable manufacturing systems. In order to ensure this reconfigurability, a robust information system is needed to manage all the actors of the production system (fixed or mobile resources, products, components, raw materials, operators, etc.). Cyber-physical production systems (CPPS) correspond to the introduction of the technical advances of the 4th industrial revolution. These systems are based on models which, from collected data, allow the evaluation of alternatives through simulations. A test phase on platforms can also allow a better validation before implementation. This chapter illustrates the impact of industrial cyber-physical systems on production systems: how they can improve current systems.

Computation of the Permeability Tensor of Non-Periodic Anisotropic Porous Media from 3D Images

Publisher : Springer Science and Business Media LLC
The direct proportionality between the flow rate and the pressure gradient of creeping flows was experimentally discovered by H. Darcy in the 19th century and theoretically justified a couple of decades ago using upscaling methods such as volume averaging or homogenization. X-ray computed micro-tomography (CMT) and pore-scale numerical simulations are increasingly used to estimate the permeability of porous media. However, the most general case of non-periodic anisotropic porous media still needs to be completely numerically defined. Pore-scale numerical methods can be split into two families. The first family is based on a direct resolution of the flow solving the Navier–Stokes equations under the assumption of creeping flow. The second one relies on the resolution of an indirect problem—such as the closure problem derived from the volume averaging theory. They are known to provide the same results in the case of periodic isotropic media or when dealing with representative element volumes. To address the most general case of non-periodic anisotropic porous media, we have identified four possible numerical approaches for the first family and two for the second. We have compared and analyzed them on three-dimensional generated geometries of increasing complexity, based on sphere and cylinder arrangements. Only one, belonging to the first family, has been proved to remain rigorously correct in the most general case. This has been successfully applied to a high-resolution 3D CMT of Carcarb, a carbon fiber preform used in the thermal protection systems of space vehicles. The study concludes with a detailed analysis of the flow behavior (streamlines and vorticity). A quantitative technique based on a vorticity criterion to determine the characteristic length of the material is proposed. Once the characterized length is known, the critical Reynolds number can be estimated and the physical limit of the creeping regime identified.

Real-Time Estimation of PEMFC Parameters Using a Continuous-Discrete Extended Kalman Filter Derived from a Pseudo Two-Dimensional Model

Authors : DIAB, Yasser AUGER, Francois SCHAEFFER, Emmanuel CHEVALIER, Stéphane ALLAHHAM, Adib
Publisher : MDPI AG
Proton Exchange Membrane Fuel Cells (PEMFCs) are clean energy conversion devices that are widely used in various energy applications. In most applications, the main challenge is accurately estimating the state of health (SoH) of the PEMFCs during dynamic operating conditions. Moreover, their behavior is affected by numerous physical phenomena such as heat and membrane flooding. This paper proposes the design of an observer to estimate the PEMFC parameters. A state-space model is first built from 2D physical equations solved by a finite difference in a discretized space domain. The discretized dynamic model is then used to design an observer based on the continuous-discrete extended Kalman filter. The observer has been validated experimentally and is used to estimate the parameters of a PEMFC under dynamic operating conditions. For several load variations, the results obtained using the proposed observer accurately characterize the dynamic responses of PEMFC in real-time.
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