bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards a New Concept of In-Line Crankshaft Balancing by Contact Less Measurement: Process for Selecting the Best Digitizing System
Authors: Zuquete-Guarato Alexandre , Mehdi-Souzani Charyar , Quinsat Yann , Lartigue Claire , Sabri Leila
Published: August 2013

Controlling the part’s balance of crankshafts are important issues for automotive manufacturers. Unbalance measurement is usually carried out using high-precision mechanical machines. The main objective of the present work is to replace mechanical measuring systems by a non-contact digitizing system, which permits the acquisition of the crankshaft surface. As the geometry to be measured presents a large variety of shapes and textures with accessibility issues, the definition of the best-suited scanning system related to geometrical and industrial constraints is a major issue.

In this direction, the paper deals with the definition of a protocol based on quality indicators associated to the collected data to compare various digitizing systems. Those quality indicators are assessed thanks to simple artifacts measurement according to a specific procedure. The comparison protocol is applied to evaluate three triangulation based digitizing systems: Results allow us to identify well-adapted digitizing systems in relation to crankshaft balancing requirements.
Knowledge-Based Automated Programming of Welding Robots for Lot-Size One Products
Authors: Hillbrand Christian , Frank Gerald
Published: August 2013

Welding is one of the most important joining techniques used in the metalworking industries. In order to exploit efficiency potentials to a maximum possible extent, robot systems are adopted to automate the welding process whenever possible. This has become standard for high volume manufacturers like the automotive industry where thousands or millions of products are manufactured in the same or a very similar way. There is, however, a large obstacle for using automated welding robots in industries with highly individualized products: The programming effort for robot systems very often exceeds the manual welding times due to small lot sizes.

Therefore this paper proposes an approach to automatically derive welding programs. The building blocks of this technique are an automatic identification of feasible candidate weld joints from a CAD model, a knowledge base and a weld program compiler. After verification of these joints by a design engineer the machine instructions for the robot system have to be derived. Therefore the proposed approach defines the necessary structures of a Welding Expert Knowledge Base (WKB) where the relevant knowledge of a welding engineer designer is modeled in terms of rules of fuzzy rule sets. On top of the WKB we propose a weld program compiler which automatically identifies the sequence of weld joints and the necessary number of welding passes, generates optimized tool paths and finally derives appropriate parameter settings.
Torque Loss Measurements on Poly V-Ribbed Belt Drive Systems
Authors: Balta Berna , Balta Bülent , Cengiz Abdülkadir , Sönmez Fazıl Önder , Arıcı Armağan
Published: August 2013

Efficient belts can provide the same magnitude of energy savings as energy-efficient motors. Therefore, belt drives deserve greater attention, so that their losses should be minimized. The belt drive power losses are a combination of torque losses and speed losses. However, the determination of belt drive behavior in terms of power losses requires extensive experimental investigations. Therefore, in this study, belt slip and torque losses were investigated experimentally with a laboratory constructed test bench. Measurement System Analysis (MSA) was performed in order to investigate the test rig reliability. Special attention was paid for experimental test setup, testing and modeling of torque loss behavior of V-ribbed belt drive systems. Significant design parameters were investigated.
Performance Assessment of Digital Hydraulics in a Quadruped Robot Leg
Authors: Peng Shuang , Branson David T. , Guglielmino Emanuele , Boaventura Thiago , Caldwell Darwin G.
Published: August 2013

This paper presents an investigation of the performance of digital hydraulic actuation in robot applications. The research compares two different hydraulic actuation systems, utilizing servo and digital hydraulic valves, developed to drive one leg of a hydraulic quadruped robot (HyQ). Comparisons between the two systems for position tracking, required flow rate and system efficiency are discussed. Results show that digital hydraulic systems can be a valid alternative to servo valves in terms of position tracking, and show that digital valves can greatly improve system performance in the form of reduced required flow rate and improved overall system efficiency.
A Batch Tracing System for Thermochemical Finishing Processes Enables New Services for Quality Management
Authors: Fleisch Ruth , Schöch Robert , Hillbrand Christian
Published: August 2013

Manufacturing processes in the area of thermochemical treatment of work pieces impose lots of challenges due to the rough environment. High temperatures and the use of chemicals are aggravating conditions of salt bath nitrocarburizing processes, which are used to improve the wear resistance, the fatigue strength, and the corrosion resistance of components made from steel, cast iron, and sintered iron materials. The process is composed of preheating, nitrocarburizing, oxidizing, and multilevel cleaning. These stages are passed through consecutively, for what customer orders are combined in batches. It is an example of a discontinuous production which is characterized by a material flow which is interrupted in time. In this context a batch is an amount of pieces which form a whole and are processed together and therefore exhibit identical attributes with regard to the manufacturing process and the product quality. At present, the implementation of batch tracing mechanisms is difficult or impossible due to the harsh environment (hazardous chemicals, high temperatures …). As a consequence, wrong assignments of the finished pieces to the customers may occur while a possibility of documentation of the parameters concerning the manufacturing process is desirable. Several of the following reasons for the enhanced deployment of batch tracing thus apply: request of customers for security and information about the origin of the products (customer pull), new laws and regulations (regulatory push), availability of innovative communication and information technology (technology push), and increase in efficiency and advance of process reliability (industry pull). In this paper, we discuss batch tracing by means of intelligent RFID technology (radio frequency identification), which involves connections to sensors for measurements of ambient parameters. Information obtained by the RFID system such as the beginning and the length of stay of the batches in the different stages is merged with the temperatures delivered by the plant equipment. Thus identifying and determination of the position of the batches is achievable throughout the entire procedure. This allows the company to offer new supplementary services to the customers and to design the process in a more flexible way like prioritizing time-critical orders. In order to prove the technical feasibility of batch tracing in the field of thermochemical treatment two test cases are described: The first one is for gathering information about the functioning of the installed RFID system, the other one is the realization of the operational process in a simplified form.
Economic Aspects in the Inspection of Multiple Geometric Tolerances
Authors: Petrò Stefano , Moroni Giovanni
Published: August 2013

Recent years have seen an increase in the adoption of geometric tolerances. Often it is possible to find several geometric tolerances defined on a single part. However, this poses inspection issues: the values of the geometric errors may be interrelated; therefore, the presence of multiple tolerances should be considered in inspection design. In this work, a methodology is proposed for planning optimal CMM sampling strategies for multiple tolerances based on the minimization of inspection costs. A model for inspection costs is proposed, which takes into account the influence of the inspection strategy on the measurement and inspection errors costs. The inspection strategy minimizing inspection cost can then be defined. The approach can be adopted both to optimize generic, uniform, sampling strategies, and to generate manufacturing specific strategies, which consider the manufacturing signature. A case study which illustrates the methodology is presented.
Elastostatic Modeling and Shape Optimization of a 6-DOF Haptic Interface Device
Authors: Caro Stéphane , Chablat Damien , Chen Chao
Published: August 2013

This paper deals with the shape optimization of a six degree-of-freedom haptic interface device. This six-dof epicyclic-parallel manipulator has all actuators located on the ground. A regular dexterous workspace is introduced to represent the mobility of user’s hand. Throughout this workspace, the deviation of the mobile platform is bounded to provide a better feeling to the user and the masses in motion are minimized to increase the transparency of the haptic device. The stiffness model is written using a virtual joint method and compared with the results obtained with the finite element analysis to be validated. Finally, the shape of the links are optimized in order to minimize the masses in motion while guaranteeing a given stiffness throughout the regular workspace of the mechanism.
Robotic Solutions Applied to Production and Measurement of Marine Propellers
Authors: Cavada Javier , Fadón Fernando
Published: August 2013

Over the past decades, robots have emerged as a valuable technological solution for multiple highly complex industrial processes, and the manufacture of marine propellers has not been an exception. Majority of the propellers being produced worldwide are custom-designed products aiming to satisfy each ship’s propulsion requirements. Such geometrical diversity is a considerable challenge when traditionally manual manufacturing processes like hand-grinding and polishing need to be automated.

In several market-leading propeller manufacturers within Europe and Asia, industrial robots are being applied for widely diverse operations such as milling polystyrene blocks to make moulding patterns, grinding out the excess material in the blade surfaces, or polishing the complete propellers’ surface before their final verification. Propeller blades are customized products, formed by curved and warped surfaces, requiring minimum 5 axes to be smoothly polished, and this can be easily achieved with a robot cell where the CAD/CAM data coming from the individual design are directly translated into robotic parameters.

While this solution has demonstrated to be perfectly capable to comply with the marine propellers finishing tolerances, which are internationally defined by ISO 484 standard rules [6], robotic solutions for propeller measurement have not been successfully implemented within this specific industry due to reasons like lack of accuracy and repeatability. This paper analyses the root causes behind this problem, identifying the calibration process, the cell alignment method and the tool positioning as the principal factors resulting in this low measuring repeatability.

Findings explained by the authors are the outcome of several practical measuring tests made on real marine propellers within ABB and Fanuc robot cells. This paper concludes offering solutions to reduce the inaccuracies caused by the mentioned factors, and recommending what type of marine propellers are more suitable to be measured with industrial robots, on the basis of ISO 484 requirements for each customized design. Moreover, suggestions for further research on this specific measuring application are provided in the concluding chapter.
Analysis of Monolithic Algorithmic Schemes for an Energy-Consistent Variational Formulation of a Coupled Thermo-Visco-Elastic Problem
Authors: Bouery Charbel , Stainier Laurent
Published: August 2013

A new variational formulation of coupled thermo-mechanical boundary-value problems has been recently proposed [1, 2], allowing to write mechanical and thermal balance equation under the form of an optimisation problem of a scalar energy-like functional. This functional is analysed in the framework of a thermo-visco-elastic problem, considering a strong coupling by taking into account the temperature dependency of mechanical properties. Different algorithmic schemes were tested, aiming to find the one that exhibits best computational performance. A simplified case shows that the optimum of the scalar energy-like functional is a saddle point.
Efficiency of Knee Braces: A Biomechanical Approach Based on Computational Modeling
Authors: Pierrat Baptiste , Molimard Jérôme , Navarro Laurent , Avril Stéphane , Calmels Paul , Edouard Pascal
Published: August 2013

Knee orthotic devices are widely proposed by physicians and medical practitioners for preventive or therapeutic objectives in relation with their effects, usually known as to stabilize joint or restrict ranges of motion. The objectives of this work are to characterize the mechanical performance of knee orthoses using a Finite Element Model of a braced human leg. The interface properties of the model are calibrated against experimental data measured by full-field measurements of 3D displacement over the surface of a patient’s leg. The results show that the mechanical action of knee braces is essentially limited by skin/fabric and skin/muscles sliding. Finally, the model leads to a better understanding of the knee/brace interaction, and of the role of the brace components on the stability of the injured knee. Thanks to this computational tool, novel brace designs can be tested and evaluated for an optimal mechanical efficiency of the devices.
On the Ability of Structural and Phenomenological Hyperelastic Models to Predict the Mechanical Behavior of Biological Tissues Submitted to Multiaxial Loadings
Authors: Nierenberger Mathieu , Rémond Yves , Ahzi Saïd
Published: August 2013

Medical surgery is currently rapidly improving and requires modeling faithfully the mechanical behavior of soft tissues. Various models exist in literature; some of them created for the study of biological materials, and others coming from the field of rubber mechanics. Indeed biological tissues show a mechanical behavior close to the one of rubbers. But while building a model, one has to keep in mind that its parameters should be loading independent and that the model should be able to predict the behavior under complex loading conditions. In addition, keeping physical parameters seems interesting since it allows a bottom up approach taking into account the microstructure of the material. In this study, the authors consider different existing hyperelastic models based on strain energy functions and identify their coefficients successively on single loading stress-stretch curves. The experimental data used, come from a paper by Zemanek dated 2009 and concerning uniaxial, equibiaxial and plane tension tests on porcine arterial walls taken in identical experimental conditions. To achieve identification, the strain energy function of each model is derived differently to provide an expression of the Cauchy stress associated to each loading case. Firstly the parameters of each model are identified on the uniaxial tension curve using a least squares method. Then, keeping the obtained parameters, predictions are made for the two other loading cases (equibiaxial and plane tension) using the associated expressions of stresses. A comparison of these predictions with experimental data is done and allows evaluating the predictive capabilities of each model for the different loading cases. A similar approach is used after swapping the loading types.

Since the predictive capabilities of the models are really dependent on the loading chosen to determine their parameters, another type of identification procedure is set up. It consists in adding the residues over the three loading cases during identification. This alternative identification method allows a better agreement between each model and the various types of experiments. This study evaluated the ability of some classical hyperelastic models to be used for a predictive scope after being identified on a specific loading type. Besides it brought to light some existing models which can describe at best the mechanical behavior of biological tissues submitted to various loadings.
Perceptive Exploration of Layout Designs Using an Interactive Genetic Algorithm
Authors: Bénabès Julien , Poirson Emilie , Bennis Fouad , Ravaut Yannick
Published: August 2013

Layout design optimization has a significant impact in the design and use of many engineering products and systems, such as the subdivision of a ship, the layout of facilities in a plant or further still the assembly of parts of a mechanism. The search for an optimal layout configuration is a critical and complex task due to the increasing demands of designers working on varied projects. A layout optimization process is generally divided into different steps: the description, formulation and solving of the problem and the final decision. This process consists in writing an optimization problem that transform designer’s requirements into variables, constraints and objectives. Then, an optimization algorithm has to be used in order to search for optimal solutions that fit with product’s specifications. This paper focuses on the last step which consists, for the designer, in making a choice on the solutions generated by the optimization algorithm. This choice is made according to the global performances of the designs and also the personal judgment of the designer. This judgment is based on the expertise of the designer and the subjective requirements that could not be integrated on the formulation of the problem. This paper proposes a perceptive exploration method, based on an Interactive Genetic Algorithm (IGA), used to explore designs, taking into account the subjective evaluation of the designer. The objective of this method is to select an ideal solution that realizes the best trade-off between the quantitative and qualitative performance criteria. This interactive process is tested on an industrial layout application which deals with the search for an optimal layout of facilities in a shelter.
Computational Design Synthesis: A Model-Based Approach for Complex Systems
Authors: Albarello Nicolas , Welcomme Jean-Baptiste
Published: August 2013

The design of systems architectures often involve a combinatorial design-space made of technological and architectural choices. A complete or large exploration of this design space requires the use of a method to generate and evaluate design alternatives. This paper proposes an innovative approach for the design-space exploration of systems architectures. The SAMOA (System Architecture Model-based OptimizAtion) tool associated to the method is also introduced. The method permits to create a large number of various system architectures combining a set of possible components to address given system functions. The method relies on models that are used to represent the problem and the solutions and to evaluate architecture performances. An algorithm first synthesizes design alternatives (a physical architecture associated to a functional allocation) based on the functional architecture of the system, the system interfaces, a library of available components and user-defined design rules. Chains of components are sequentially added to an initially empty architecture until all functions are fulfilled. The design rules permit to guarantee the viability and validity of the chains of components and, consequently, of the generated architectures. The design space exploration is then performed in a smart way through the use of an evolutionary algorithm, the evolution mechanisms of which are specific to system architecting. Evaluation modules permit to assess the performances of alternatives based on the structure of the architecture model and the data embedded in the component models. These performances are used to select the best generated architectures considering constraints and quality metrics. This selection is based on the Pareto-dominance-based NSGA-II algorithm or, alternatively, on an interactive preference-based algorithm. Iterating over this evolution-evaluation-selection process permits to increase the quality of solutions and, thus, to highlight the regions of interest of the design-space which can be used as a base for further manual investigations. By using this method, the system designers have a larger confidence in the optimality of the adopted architecture than using a classical derivative approach as many more solutions are evaluated. Also, the method permits to quickly evaluate the trade-offs between the different considered criteria. Finally, the method can also be used to evaluate the impact of a technology on the system performances not only by a substituting a technology by another but also by adapting the architecture of the system.
Optimal Design of an Asymmetrical Sandwich Panel for Acoustical and Mechanical Properties
Authors: Leite Pierre , Thomas Marc , Simon Frank , Bréchet Yves
Published: August 2013

The aim of the present study is to develop specific tools to design optimal panels for multi-objective applications. The objectives considered are stiffness, strength and acoustic insulation at minimum weight. A genetic algorithm is used to design optimal sandwich structures with a good balance of mechanical and acoustical properties. The bending stiffness and mechanical strength of the panel are calculated using beam theory. This analysis is focused on a 3-point bending test, giving the stiffness as the ratio between the concentrated force and the deflection at the center of the sandwich panel. The strength is calculated as the critical force at the onset of plastic deformation. A vibro-acoustical model based on Lagrange’s equations is used to give access to the sound transmission loss of the sandwich panel with anisotropic elastic layers. The main interest is on the mean transmission loss for a diffused incident acoustic field over the frequency range 500–10000Hz. First of all, the optimal design for mechanical properties is assessed at a minimal weight. Quite expectedly, the best solutions are composite-skin with high specific stiffness and soft cores with high shear modulus for a minimum weight. The geometry depends on the required stiffness and strength. The design/properties relationship is discussed by monitoring the evolution of both the material properties and the geometry of the panel. Similarly, a parametric study is performed for acoustical design at minimal weight. In order to maximize the mean transmission loss, it is preferable to lower the critical frequency for which acoustic radiating is maximal. Then, the best solutions for the panel are those who maximize the square root of the density over Young’s modulus. The trade-off between mass and loss transmission is then explored. A comparison between all these solutions provides significant differences in the design with respect to the objectives. In the next step, a multi-objective genetic algorithm is used to find an optimized panel with a good compromise between acoustical and mechanical properties. The optimization is considered with several approaches depending on whether the mass is regarded as the cost function or as a constraint. This study thus provides a preview of the capabilities of multi-objective optimization in design of sandwich panel.
A Quantitative Discrete Element Model to Investigate Sub-Surface Damage due to Surface Polishing
Authors: André Damien , Iordanoff Ivan , Charles Jean-luc , Néauport Jérôme
Published: August 2013

This work is a continuation of a previous study that investigated sub-surface damage in silica glass due to surface polishing. In this previous study, discrete element models have shown qualitatively good agreement with experiments. The presented work propose a model allowing quantitative results by focusing on the continuous part of the problem. Special attemption was given to the discrete element model of silica glass considered as perfectly isotropic, elastic and brittle. To validate this approach, numerical results are compared to experimental data from literature.
Derivation of a New Model Including the Effect of Swelling on Finite Strain Properties for Polymeric Gels
Authors: Brulliard Violette , Verron Erwan , Le Corre Steven
Published: August 2013

Polymeric gels consist in a cross-linked polymer chains network which contains a large quantity of solvent molecules. The main property of gels is their ability to absorb solvent molecules without being dissolved, and to shrink when they release fluid. This swelling/deswelling phenomenon involves large volume changes of the gel, when the solvent diffuses into the large strain elastic solid.

In recent literature, constitutive equations, in which the gel is considered as a single continuum body, have been derived to describe such a coupled deformation/diffusion problem. However, these works are based on the simple mono-dimensional models of both Flory and Treloar devoted to rubber swelling. The aim of the present work is the derivation of a new constitutive equation based on an original definition of the elastic strain energy. The differences with the classical theory are highlighted on two simple examples.
Arms Swing Effects on a Walking Planar Biped
Authors: Kaddar Bassel , Aoustin Yannick , Chevallereau Christine
Published: August 2013

A walking gait is designed for a planar biped with two identical three-link legs, a trunk and two one-link arms. This nine-link biped is controlled via eight torques to obtain one step of a cyclic gait. The scope of this paper is to investigate the effects of arms swing on the energy consumption during walking of a fully actuated planar biped robot. Kinematics and dynamics of a biped, HYDROID, are used for this study. Desired gaits are considered to be cyclic having single support phases separated by flat foot impacts. Different evolutions of the arms: arms held, arms bound and arms swing are compared. For each case, we use a parametric optimization method with constraints to produce reference cyclic trajectories according to an energy criterion. The numerical results show that this criterion is lower in the case where the arms swing.
Bearings Influence on the Dynamic Behavior of HSM Spindle
Authors: Noel David , Ritou Mathieu , Le Loch Sebastien , Furet Benoit
Published: August 2013

The aeronautic industry requires high speed and high power spindles to obtain high material removal rates during long rough milling operations. The weakness of HSM spindle is the bearings, although high precision hybrid ball bearings have been developed to achieve this critical application. Inadequate use of spindles inevitably leads to shortened lifetimes. Choosing the operating conditions is a required step before machining applications. It can be achieved through either experimental tests or numerical modeling that leads to stability lobe diagrams. Stability of cuts relies on the dynamic behavior of the spindle, which is particularly due to the eigenfrequencies of the tool-shaft assembly. The frequencies depend on bearing stiffness that can change under operating conditions. That is why the impact of cutting conditions and bearing parameters on its stiffness are studied in the paper. A five degrees of freedom model of angular ball bearing is briefly presented. A complete bearing model is introduced. The originality of the approach is the complete technological modeling, notably of the radial expansions of inner and outer rings of bearing. A non-linear expression is established from continuum mechanics model. The influence of geometry of bearing, operating conditions and design parameters of spindle on the bearing stiffness are established and analysed. Then, modal analyses of the tool-spindle assembly are carried out in relation to the varying bearing stiffness. Finally, significance of the approach is demonstrated through the analyses of Frequency Response Function.
Comparison of Stress Distribution Pattern in Orthodontic Bracket- Adhesive- Tooth System During Treatment Time and Debonding Stage
Authors: Hajizadeh Maryam , Ghalichi Farzan , Mirzakouchaki Behnam , Shahrbaf Shirin
Published: August 2013

Fixed orthodontic treatment is based on effective bonding of bracket to enamel surface. During orthodontic therapy, load is applied on bracket slot by orthodontic wire, and then it is transferred to adhesive layer and enamel surface (state I). After the completion of treatment period, orthodontic brackets are debonded by load application on the incisal region of bracket-adhesive interface (state II).

In order to compare the diversity in stress distribution pattern of these two states, micro CT images of maxillary premolar tooth and bracket were transformed to STL files and imported to Hypermesh software to create high quality 3D finite element models. Space between enamel and bracket was filled with orthodontic adhesive material which sets to 0.2 mm at thickest region. Mechanical property was assigned to each layer and appropriate boundary conditions were applied. By using a load distributing element RBE3, firstly 150 N shear load was applied on the bracket slot to simulate bracket-adhesive-tooth system of state I and secondly the same load was applied on the incisal area of bracket and bracket-adhesive bonding to simulate bracket-adhesive-tooth system of state II.

Generated stresses on the bracket, the adhesive and the tooth in both systems were obtained and compared to each other. The Findings of this study, reveal that the effect of bonding loads was directly transform to the adhesive layer and the enamel surface; hence, treatment period would decrease.

Alternatively, debonding loads would bring about higher stresses on the bracket and facilitate debonding action.
An Extended Higher-Order Free Vibration Analysis of Composite Sandwich Beam With Viscoelastic Core
Authors: Sadeghnejad Soroush , Sadighi Mojtaba , Hamedani Abdolreza Ohadi
Published: August 2013

Free vibration analysis of sandwich beam with a viscoelastic core based on the extended high-order sandwich panel theory approach is presented. The effects of transverse shear and core compressibility are of high importance in sandwich structures, having an influence on the entire structural behavior especially in vibrations. For applications involving stiffer cores, the high-order sandwich panel theory (HSAPT) cannot accurately predict the shear and axial stress distributions in the core. Thus, by using the “Extended High-Order Sandwich Panel Theory” (EHSAPT), the in-plane rigidity of the core is considered in addition to the compressibility of the core in the transverse direction. The novelty of this theory is that it allows for three generalized coordinates in the core (the axial and transverse displacements at the centroid of the core, and the rotation at the centroid of the core) instead of just one (mid-point transverse displacement) commonly adopted in other available theories. The mathematical formulation uses the Hamilton principle and includes derivation of the governing equations along with the appropriate boundary conditions. The formulation uses the classical thin plate theory for the face sheets and a two-dimensional elasticity theory or equivalent one for the core. In addition, Young modulus, rotational inertia, and kinetic energy of the core are considered and core is assumed as an orthotropic viscoelastic material. The analysis is applicable for any types of loading scheme, localized as well as distributed, and distinguish between loads applied at the upper or the lower face. The obtained results are compared with recent research published by the present authors which was done numerically by using FEM on viscoelastic sandwich beam and the corresponding results of other previous researches. The influence of material properties, face layup and geometry effect on natural frequencies of composite sandwich beams are investigated.
A Graph Search Approach to Automate Product Concept Translation
Authors: Yeo Il , Patil Lalit , Dutta Debasish
Published: August 2013

Product data translation is essential for the seamless integration of various product-centric activities. Yet, the process to build translators among different software has been left mostly to individual expertise rather than a formal procedure. In this paper, we propose a framework to automatically determine translation rules to enable translation of instances from one system to another. We use a graph search method to obtain the overall translation rule as a combination of multiple basic functions. We apply this method to a subset of non-geometric product knowledge, such as date of creation, color and name of feature used in two commercial systems. We detect the rules using a manually created training data set and evaluate their correctness manually.
A Decision Tool for Green Manufacturing While Utilizing Additive Process
Authors: Santos Ana L. , Almeida Henrique A. , Bártolo Helena , Bártolo Paulo J.
Published: August 2013

The increasing growth of human population together with the material consumption of most industrialised nations taking place at an unsustainable rate have been causing the degradation of the planet. The implementation of sustainable methodologies can contribute to the implementation of more ecological practices. A computational tool integrating ecodesign principles was developed to support sustainable decisions. This tool allows designers and clients to investigate and compare different solutions for each product, taking into account the whole product life cycle, as well to incorporate the product’s physical data with the CAD model. In this work a decision computational tool was used combined with the additive manufacturing study case. This system can contribute to a more sustainable manufacturing product development, facilitating the evaluation of the environmental impact analysis, optimization and comparison of the product life cycle.
Laser Milling of Precision Mechanics for Space Instruments
Authors: Porter Jyri , Lappalainen Kauko
Published: August 2013

This paper presents how laser milling can replace conventional milling for producing selected features in thin-walled structures of space instrument parts. Example parts are shown.

In the final stages of the manufacturing process the produced thin-walled structures require special attention to avoid vibration, unwanted deformation and even catastrophic destruction of the part. This requires careful planning of machining operations and fixture design which in turn can take considerable time.

Laser milling is a slow material removal process. It is generally used only for finishing features that normal chip cutting tools cannot reach. However, in the case of the part having thin-walled structures, laser milling has the extra benefit of causing practically no deflection or vibration due to machining forces and consequently it requires minimal fixturing.

Generally the laser beam should mill the material in the direction of its smallest depth to minimize recast and form errors that accumulate layer by layer. It is also possible to mill out solid chunks of material without fear of catastrophic collisions, unlike in chip cutting. This can reduce the milled volume thus speeding up the process considerably. Laser milling has special requirements with regard to the depth-width ratio of cavities, sidewall verticalness, and geometrical form of the raw stock. One must also consider where the laser beam hits after perforating the desired surface.

In many cases combining laser milling with traditional machining is the fastest way to produce one-of-a-kind parts.
Know What You Need to Know: The Role of Technological Knowledge in Product Service Systems
Authors: Thenent Nils E. , Settanni Ettore , Newnes Linda B.
Published: August 2013

An emerging trend in defence and aerospace is the move from manufacturing and selling products to providing the availability of a product-related function based on long term contractual agreements between the customer and the service provider. Therefore the concern of the manufacturer as a service provider shifts towards all means that are required to ensure the availability of the product related function. This ultimately imposes the adoption of a broader perspective on a complex system of interconnected and interdependent activities undertaken by a diverse network of stakeholders for the achievement of a common purpose. Nonetheless, a consistent and comprehensive way to represent such complex systems is not yet agreed upon in the literature. For the purpose of estimating the costs of a Product Service System (PSS) delivery, a consistent and common representation of products and services is a necessary precondition.

The focus of this paper is to contribute to the debate by proposing the use of knowledge as the underlying foundation for representing products, services and PSS.

Building upon inter-disciplinary literature, differing concepts of PSS are discussed, in order to identify recurring aspects and commonalities between product and service. While it could be recognised that technology represents such a common element, it is also recognised that differing definitions of technology do not facilitate the discussion about product, service, and PSS. Instead, evidence is found for the argument that applied knowledge can be seen as the underlying foundation for products, service and PSS. In this sense, knowledge is not considered as a single asset, but rather a composition of different kinds of knowledge.

The authors propose the application of knowledge to a process-based approach, which facilitates the representation of products and services by overcoming their distinction in a consistent way. While the composition of knowledge related to each process is a necessary precondition to enable the successful delivery of a PSS, it furthermore requires knowledge about integration of all process inputs, outputs and the processes’ dynamics within a given environment. Herewith the focus shifts to the preconditions that enable the successful delivery of a PSS, such as available set of skills and underlying process understanding.

Discussing the role knowledge plays in current cost estimation methods it is found that — despite its importance — knowledge is not always clearly defined, and very often it is reduced to repository-based data retrieval systems.

The proposed knowledge-based process-orientated approach aims to facilitate investigating products, services, PSS, and the underlying production and delivery systems by representing them in a transparent and consistent way. While this is generally not bound to a particular type of analysis, the motivation originates from estimating the costs of a PSS delivery.
An Information System for Driving the Future PLM for Museum: The DHRM, Digital Heritage Reference Model
Authors: Hervy Benjamin , Laroche Florent , Bernard Alain
Published: August 2013

In this article we propose a new way for enriching technical models that drive contemporary enterprise. Our proposition is to take into account a new stage in the object lifecycle: at its end, it enters into a new phase that we call “heritage lifecycle”. Indeed, many old technical objects fall in ruins and are destroyed after their uses. After capitalization, we propose to conserve them virtually. Thanks to virtual tools coupled to database, it will help us to define a new information system for driving the long life cycle of objects: it is the Digital Heritage Reference Model, DHRM. This information system will be implemented in a new PLM dedicated to museum, place where know-how and mankind’s knowledge is stored and promoted when possible. Museum-related PLM would eventually interact with enterprises PLM as a bijective enrichment.
An Experimental Investigation on Aerospace Quality Gears Operating in Loss of Lubrication Condition
Authors: Bartilotta Ida , Ciulli Enrico , Manconi Salvatore , Toson Elena
Published: August 2013

This paper shows the results of an experimental study carried out on spur gears for aerospace applications operating in loss of lubrication. The aim of this work was to establish a baseline for gear behavior under oil off conditions. A total amount of 40 tests were performed with gears made from 2 materials operating at different levels of sliding speed and contact pressure. In some cases the bulk temperature was measured to evaluate the heating of the running gear. A more relevant wear and heating of the gears was observed with the increase of the contact pressure rather than with the increase of the sliding speed. In all the tests the transmission was able to transfer the required power. However some tests were stopped before the required time because of the overcoming of the rig safety threshold. The results showed a different oil off time depending on the material.
Designing a Networked Telerobotic System Using Internet
Authors: Tarca Radu , Cornea Mihai , Tarca Ioan , Vesselenyi Tiberiu
Published: August 2013

Experimentation is a very important part of education in engineering including mechatronics engineering, which is a relatively new field, combining three engineering disciplines: mechanical engineering, electrical engineering and software engineering. The equipments needed for experiments in mechatronics are usually expensive. A solution to make these expensive equipments achievable is to share them with other universities or research centers from different locations in the world.

The goal of our team is to build a networked telerobot system so that the Internet users, especially researchers and students, can be able to control an autonomous robot able to explore a dynamic environment remotely from their home and share the robot system with the department. The particularity of the environment, in this case, is that the experiment uses grid lines painted on the floor, for robot navigation purpose.

The system which is still under development will be able to increase the number of robots. The communication software technologies are based on PHP. A specific protocol over IP was designed for communication between the server and clients.

The aim of this project is oriented toward providing a telerobot system with a high degree of local intelligence in order to overcome restricted bandwidth and transmission delay of the network.
Imitation of Human Body Poses by the Formation Control of a Fluidic Swarm
Authors: Tilki Umut , Erkmen Ismet , Erkmen Aydan M.
Published: August 2013

Imitation learning is one of the forms of social learning that enables the human or robot agents to learn new skills. The knowledge acquired for imitation can be basically represented as action mapping based on “organ matching” which determines the correspondence between imitator and imitatee, if the imitator and the demonstrator share the same embodiment. In this paper, we aim at imitation of two system with totally different dynamics, imitating each other, where any correspondence is missing. Towards this aim, we adopt a case where the imitator is a fluidic system which dynamics is totally different than the imitatee, that is a human performing different body poses. Our work proposes the fluidics formation control of fluid particles where the formation results from the imitation of observed human body poses. Fluidic formation control layer is responsible of assigning the correct fluid parameters to the swarm formation layer according to the body poses adopted by the human performer. The movement of the fluid particles is modeled using the Smoothed Particle Hydrodynamics (SPH) which is a particle based Lagrangian method for simulation of fluid flows. The region based controller first extract the human body parts generating the regions where the attention is attracted by the imitatee and fits an appropriate ellipses to delimite boundaries of those regions. The ellipse parameters such as center of the ellipses, eccentricity, length of the major and minor axis etc. are used by the fludic layer in order to generate human body poses. This paper introduces our technique and demonstrates the imitation performance of our system.
Integrated and Consistent Management of Product-Process Information
Authors: Demoly Frédéric , Kiritsis Dimitris
Published: August 2013

The paper describes an approach to product relationships management in the context of concurrent engineering and product lifecycle management (PLM). Current industrial practices in Product Data Management and Manufacturing Process Management systems require better efficiency, flexibility, and sensitivity in managing product information at various levels of abstraction throughout its lifecycle. The aim of the proposed work is to manage vital yet complex and inherent product relationship information to enable concurrent product design and assembly sequence planning. Indeed, the definition of the product with its assembly sequence requires the management and the understanding of the numerous product relationships, ensuring consistency between the product and its components. This main objective stresses the relational design paradigm by focusing on product relationships along its lifecycle. This paper gives the detailed description of the background and models which highlight the need for a more efficient PLM approach; then the theoretical approach is described.
A Top-Down Approach for Virtual Redesign and Ergonomic Optimization of an Agricultural Tractor’s Driver Cab
Authors: Di Gironimo Giuseppe , Lanzotti Antonio , Melemez Kenan , Renno Fabrizio
Published: August 2013

Nowadays, economical, technical and ergonomic factors have a great importance on the design of the agricultural tractors. The paper illustrates the use and the management of heterogeneous product information (manual measurements and drafts, 2D drawings, technical documentation, photos), advanced CAD modeling tools and digital human models, for the redesign and the ergonomic optimization of an agricultural tractor’s driver cab. The project development has been organized using a top–down approach in a collaborative environment. At first, a manual measurement with gauges allowed to realize a technical draft of the whole agricultural tractor and of each component part of the driver cab. Then a main skeleton has been created in Catia V5 environment in order to specify all the datum elements necessary to model each sub-assembly of the tractor. Cabin, platform, engine, tires, seat, dashboard and controls have been organized separately and modeled considering the details related to the manual measurements and to the technical standards. Once obtained the 3D CAD model of the tractor, an opportune questionnaire was prepared and a test campaign was carried out with real operators in order to define the more critical control devices within the driver cab, as regards to usability and ergonomic issues. An “Ergonomics’ Evaluation Index” (EEI) was defined taking into account the posture angles of the operator and the Rapid Upper Limb Assessment analysis tool available in the “Ergonomics Design & Analysis” module of Catia V5 based on the use of a digital human model. The index was validated comparing the results of tests carried out using virtual manikins of different percentiles performing a specific driving task, with the results of tests carried out by real operators, of the same percentiles, performing the same driving task. Critical values of the EEI obtained during some driving tasks in virtual environment, suggested to modify the shape and the position of some control devices in order to optimize the ergonomics of the driver cab. The adoption of the top-down modeling based approach allowed each change on a singular component part to be automatically propagated on the whole assembly, making easy the changes on the virtual prototype.