Postprocesamiento CAM-ROBOTICA orientado al prototipado y mecanizado en células robotizadas complejas

The main interest of this thesis consists of the study and implementation of postprocessors to adapt the toolpath generated by a Computer Aided Manufacturing (CAM) system to a complex robotic workcell of eight joints, devoted to the rapid prototyping of 3D CAD-defined products. It consists of a 6R industrial manipulator mounted on a linear track and synchronized with a rotary table. To accomplish this main objective, previous work is required. Each task carried out entails a methodology, objective and partial results that complement each other, namely: - It is described the architecture of the workcell in depth, at both displacement and joint-rate levels, for both direct and inverse resolutions. The conditioning of the Jacobian matrix is described as kinetostatic performance index to evaluate the vicinity to singular postures. These ones are analysed from a geometric point of view. - Prior to any machining, the additional external joints require a calibration done in situ, usually in an industrial environment. A novel Non-contact Planar Constraint Calibration method is developed to estimate the external joints configuration parameters by means of a laser displacement sensor. - A first control is originally done by means of a fuzzy inference engine at the displacement level, which is integrated within the postprocessor of the CAM software. - Several Redundancy Resolution Schemes (RRS) at the joint-rate level are compared for the configuration of the postprocessor, dealing not only with the additional joints (intrinsic redundancy) but also with the redundancy due to the symmetry on the milling tool (functional redundancy). - The use of these schemes is optimized by adjusting two performance criterion vectors related to both singularity avoidance and maintenance of a preferred reference posture, as secondary tasks to be done during the path tracking. Two innovative fuzzy inference engines actively adjust the weight of each joint in these tasks.Andrés De La Esperanza, FJ. (2011). Postprocesamiento CAM-ROBOTICA orientado al prototipado y mecanizado en células robotizadas complejas [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/10627Palanci

CAM-Rob postprocessor based on a fuzzified redundancy resolution scheme

This work highlights the applicability of different redundancy resolution schemes to the postprocessing stage from a computer-aided manufacturing (CAM) system to an industrial redundant workcell. The inverse kinematic problem for redundant manipulators is not straightforward and, therefore, it is commonly solved using an iteratively approach based on redundant resolution schemes at the velocity level. In this work, two conceptions of redundancy resolution schemes are evaluated and a novel fuzzy inference system is developed to improve the performance during the toolpath tracking in order to avoid singularities and to maintain a preferred reference posture. For this purpose, the fuzzy inference engine properly adjusts the weight of each joint in the calculation of the performance criterion vectors. The proposed approach is validated in the real prototyping of a windmill blademold using a KUKA KR15/2manipulator mounted on a linear track and synchronized with a rotary table. To the authors knowledge, the proposed method and the results shown are novel in the context of postprocessing techniques from CAM systems to industrial robots devoted to milling works. With the same guidelines, the postprocessor programmed inside the CAM system is expected to be easily applicable not only to other industrial robots, but also for different applications such as welding or painting labors.This research is partially supported by the Technical University of Valencia (PAID-00-09-3092, PAID-05-11-2640), project PROMETEO 2009/063 of Generalitat Valenciana and research project DPI2009-14744-C03-01 of the Spanish Government.Andrés De La Esperanza, FJ.; Gracia Calandin, LI.; Tornero Montserrat, J. (2012). CAM-Rob postprocessor based on a fuzzified redundancy resolution scheme. International Journal of Advanced Manufacturing Technology. 62(5):705-718. https://doi.org/10.1007/s00170-011-3836-yS705718625Andres J, Gracia L, Tornero J (2011) Calibration and control of a redundant robotic workcell for milling tasks. Int J Comp Int Manuf 24(6):561–573Patel RV, Shadpey F (2005) Control of redundant robot manipulators: theory and experiments. Springer, New YorkHartenberg RS, Denavit J (1955) A kinematic notation for lower pair mechanisms based on matrices. Trans ASME J App Mech 77:215–221Andres J, Gracia L, Tornero J (2009) Inverse kinematics of a redundant manipulator for CAM integration. An industrial perspective of implementation, Proceedings of the 2009 IEEE International Conference on Mechatronics, MalagaWhitney DE (1969) Resolved motion rate control of manipulators and human prostheses. IEEE Trans Man-Machine Syst 10(2):47–53Whitney DE (1972) The mathematics of coordinated control of prosthetic arms and manipulator, ASME J. Dyn Sys Meas Cont 94(4):303–309Angeles J (2003) Fundamentals of robotic mechanical systems: theory, methods and algorithms. Springer, New YorkHuo L, Baron L (2008) The joint-limits and singularity avoidance in robotic welding. Industrial Robot 35(5):456–464Liégeois A (1977) Automatic supervisory control of the configuration and behavior of multibody mechanisms. IEEE Trans Syst Man Cybern SMC-7:245–250Gracia L, Andres J, Tornero J (2009) Trajectory tracking with a 6R serial industrial robot with ordinary and non-ordinary singularities. Int J Cont Auto Syst 7(1):85–96Angeles J, López-Cajún CS (1992) Kinematic isotropy and the conditioning index of serial robotic manipulators. Int J Robot Res 11(6):560–570Khan WA, Angeles J (2006) The kinetostatic optimization of robotic manipulators: the inverse and the direct problems. J Mech Des 128(1):168–178Siemens Corp (2009) NX Documentation. In: {$UGII_base_dir}\UGDOCMaza JI, Ollero A (2000) Herramienta MATLAB-Simulink para la simulación y el control de robots manipuladores y móviles, Actas de las XXI Jornadas de Automática, Sevilla, SpainRoger Jang JS, Gulley N (2008) Fuzzy logic toolbox: user’s guide; revised for version 2.2.7. The Math Works, Inc.Qdesign SRL (2007) CAD-CAM off line programming for industrial robots. ROBOmove on line help v. 2.0 [online]. Available from: http://www.qdrobotics.com/eng/robomove.php . Accessed 28 Nov 2011Andrés J, Gracia L, Marti H, Tornero J (2009) Toolpath postprocessing for three axes milling in redudant robotic workcells by means of fuzzy integration in a CAM platform, Proceedings of the IEEE International Conference on Mechatronics, Malaga, Spai

Manufacture of Green-Composite Sandwich Structures with Basalt Fiber and Bioepoxy Resin

Nowadays, there is a growing interest for the use and development ofmaterials synthesized fromrenewable sources in the polymer composites manufacturing industry; this applies for both matrix and reinforcement components. In the present research, a novel basalt fibre reinforced (BFR) bioepoxy green composite is proposed as an environmentally friendly alternative to traditional petroleum-derived composites. In addition, this material system was combined with cork as core material for the fabrication of fibre composite sandwich structures. Mechanical properties of both skin and core materials were assessed through flexural and tensile tests. Finite element (FEM) simulations for the mechanical stress analysis of the sandwich material were carried out, and a maximumallowable shear stress for material failure under bending loads was established. Permeabilitymeasurements of the basalt fabrics were carried out in order to perform numerical simulations of liquid composite moulding (LCM) processes on the PAMRTM software. The proposed green-composite sandwich material was used for the fabrication of a longboard as a case study for a sports equipment application. Numerical simulations of the mould filling stage allowed the determination of an optimal mould filling strategy. Finally, the load-bearing capacity of the board was studied by means of FEM simulations, and the presented design proved to be acceptable for service.This research work is supported by the Spanish Ministerio de Ciencia e Innovacion, Project DPI2010-20333, and the Generalitat Valenciana through Programme PROME-TEO/2009/063.Torres, J.; Hoto, R.; Andrés De La Esperanza, FJ.; García Manrique, JA. (2013). Manufacture of Green-Composite Sandwich Structures with Basalt Fiber and Bioepoxy Resin. Advances in Materials Science and Engineering. 2013:1-9. https://doi.org/10.1155/2013/214506S19201

Role of age and comorbidities in mortality of patients with infective endocarditis

[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group

Çédille, revista de estudios franceses

Presentació

Spatiotemporal Characteristics of the Largest HIV-1 CRF02_AG Outbreak in Spain: Evidence for Onward Transmissions

Background and Aim: The circulating recombinant form 02_AG (CRF02_AG) is the predominant clade among the human immunodeficiency virus type-1 (HIV-1) non-Bs with a prevalence of 5.97% (95% Confidence Interval-CI: 5.41–6.57%) across Spain. Our aim was to estimate the levels of regional clustering for CRF02_AG and the spatiotemporal characteristics of the largest CRF02_AG subepidemic in Spain.Methods: We studied 396 CRF02_AG sequences obtained from HIV-1 diagnosed patients during 2000–2014 from 10 autonomous communities of Spain. Phylogenetic analysis was performed on the 391 CRF02_AG sequences along with all globally sampled CRF02_AG sequences (N = 3,302) as references. Phylodynamic and phylogeographic analysis was performed to the largest CRF02_AG monophyletic cluster by a Bayesian method in BEAST v1.8.0 and by reconstructing ancestral states using the criterion of parsimony in Mesquite v3.4, respectively.Results: The HIV-1 CRF02_AG prevalence differed across Spanish autonomous communities we sampled from (p &lt; 0.001). Phylogenetic analysis revealed that 52.7% of the CRF02_AG sequences formed 56 monophyletic clusters, with a range of 2–79 sequences. The CRF02_AG regional dispersal differed across Spain (p = 0.003), as suggested by monophyletic clustering. For the largest monophyletic cluster (subepidemic) (N = 79), 49.4% of the clustered sequences originated from Madrid, while most sequences (51.9%) had been obtained from men having sex with men (MSM). Molecular clock analysis suggested that the origin (tMRCA) of the CRF02_AG subepidemic was in 2002 (median estimate; 95% Highest Posterior Density-HPD interval: 1999–2004). Additionally, we found significant clustering within the CRF02_AG subepidemic according to the ethnic origin.Conclusion: CRF02_AG has been introduced as a result of multiple introductions in Spain, following regional dispersal in several cases. We showed that CRF02_AG transmissions were mostly due to regional dispersal in Spain. The hot-spot for the largest CRF02_AG regional subepidemic in Spain was in Madrid associated with MSM transmission risk group. The existence of subepidemics suggest that several spillovers occurred from Madrid to other areas. CRF02_AG sequences from Hispanics were clustered in a separate subclade suggesting no linkage between the local and Hispanic subepidemics

Estimación de posturas de agarre en base a ACP y RN

Comunicación presentada en el XXI Congreso Nacional de Ingeniería Mecánica, celebrado en Elche en Noviembre de 2016.La investigación en manos antropomorfas robóticas y protésicas experimenta un auge en la actualidad. Unos diseños intentan lograr un agarre estable y diestro mientras que otros pretenden alcanzar un elevado grado de antropomorfismo y de apariencia cosmética. Sin embargo, las prótesis de mano existentes suelen ser muy simples desde un punto de vista biomecánico. Esto se debe a la complejidad de establecer una interacción adecuada entre el amputado y una prótesis de múltiples grados de libertad, que requeriría numerosas señales de control independientes y un controlador inteligente. Una innovación en el ámbito del control de manos artificiales podría derivarse de la observación e imitación del comportamiento biomecánico natural, en base a un espacio de dimensionalidad reducida. El presente trabajo plantea la utilización del análisis de componentes principales (ACP), para reducir la dimensionalidad del problema de control, en combinación con las redes neuronales (RN), para predecir la posturas de la mano en dos tipos de agarre sobre objetos cilíndricos: un agarre de potencia (cilíndrico) y un agarre de precisión (pinza con 5 dedos). El objetivo es determinar el mínimo número de entradas de control necesarias para que una mano protésica avanzada pueda realizar actividades de la vida diaria en base a patrones posturales identificados y evaluar su posibilidad de control real. Para ello, se realizaron experimentos de agarre con 16 sujetos diestros y 4 cilindros de diversos diámetros durante los que se registró la posición de 32 marcadores. A partir de estos datos se calcularon los ángulos de articulación de la mano para cada postura de agarre (PA). Posteriormente, se realizó un ACP sobre los datos de PA, obteniendo 7 componentes principales (posturas propias de agarre, PPA) que determinaron las sinergias posturales producidas durante el agarre. El resultado se simuló mediante OpenSim. Los datos obtenidos se utilizaron para entrenar y validar una RN para estimar PA a partir de las PPA, con una arquitectura previamente validada compuesta por dos capas. Finalmente, se calculó la raíz cuadrada del error cuadrático medio global y por articulación de la predicción realizada por la RN con respecto a la postura experimental, obteniendo resultados alentadores.El presente trabajo está financiado por la Generalitat Valenciana a través del proyecto GV/2015/101

Study of the Proper Sintering Conditions of Anionically-Polymerized Polyamide 6 Matrices for the Fabrication of Greencomposites

[EN] The present research work assesses the manufacture of long fiber thermoplastic matrix composite materials (GreenComposites). Thermoplastic matrices are too viscous to be injected into the conventional LCM (Liquid Composite Molding) molds, and then epoxy, polyester or vinylester resins are used. Nevertheless, the groundbreaking anionic polymerization of caprolactam allows such a synthesis of a thermoplastic APA6 matrix inside the mold. This matrix is sintered from the starting monomers, and presents high mechanical performance and recyclability. In order to do the reactive injection in a LCM mold, it is necessary to control the polymerization mechanism of such a thermoplastic matrix. This paper puts special emphasis on detecting and solving all problems which arose during synthesis. For instance, moisture values were assessed for all starting reactants, since humidity keeps polymerization from occurring. It is thought that once the synthesis and the resulting material characterization are well controlled, the manufacture of GreenComposites through in situ polymerization, as well as addition of state-of-the-art fabrics such as basalt, can proceed successfully.Alfonso, A.; Andres De La Esperanza, FJ.; García Manrique, JA. (2012). Study of the Proper Sintering Conditions of Anionically-Polymerized Polyamide 6 Matrices for the Fabrication of Greencomposites. MATERIALS SCIENCE FORUM. 713:121-126. doi:10.4028/www.scientific.net/MSF.713.121S121126713K. van Rijswijk: Composites, Part A Vol. 37 (2006), pp.949-956.K. van Rijswijk: Composites, Part A Vol. 40 (2009), pp.1-10.V. Fiore: Mat. and Des. Vol. 32 (2011), p.2091-(2099).L. Ricco, S. Russ, G. Orefice and F. Riva: Macromolecules Vol. 32 (1999), pp.26-31.K. van Rijswijk: Composites: Part A Vol. 37 (2006), pp.949-956.Information on www. brueggemann. com/english/caprolactam-anionische-polym. html.F. M. Kogan and O. V. Nikitina: Env. Health Persp. Vol. 102(5) (1994), p.205–206.K. van Rijswijk and H.E.N. Bersee: Composites, Part A Vol. 38 (2007), pp.666-681

An Efficient Thermoplastic Composite (TpC) Manufacture for High-Performance Parts: Comparison of Three Liquid Composite Moulding Processes

[EN] Although light and performing, common thermosetting-matrix composite material cannot be recycled. Designing thermoplastic-infusion equipment is thus a technological as well as an ecological achievement. The context of the fuel-efficiency competition Eco-Marathon sponsored by Shell is perfectly suited for such an innovation. Our team is designing a process based on injecting thermoplastic monomer with initiator and activator letting the polymerization occur within the mold and thus avoiding the high viscosity of liquid thermoplastic [1]-[2]. Choosing the adequate process to produce a high performance composite part is essential. In this paper are compared three LCM processes, the classic Resin Transfer Molding (RTM), the Vacuum Assisted Resin Infusion (VARI) and Seeman¿s Composite Resin Infusion Molding Process (SCRIMP) using the example of the Shell Eco-Marathon vehicle¿s body. Our parameters of comparison are the quality of the produced part (void content) and the production time. The main issue in composite part quality is the formation of porosity. This entrapment is linked to the fiber tow impregnation and thus to the different liquid velocities within and between these fiber tows. The tow impregnation was taken in account by using an empirical model of evolution of the permeability: the more saturated the tow, the lower the permeability.Molle, G.; García Manrique, JA.; Masquelier, I.; Andrés De La Esperanza, FJ. (2011). An Efficient Thermoplastic Composite (TpC) Manufacture for High-Performance Parts: Comparison of Three Liquid Composite Moulding Processes. International Review of Chemical Engineering (IRECHE). 3(1):128-133. http://hdl.handle.net/10251/108474S1281333

A numerical simulation of woven/anionic polyamide 6 composite part manufacturing using structural reactive injection moulding process

In this work, a structural reactive injection moulding process using reactive anionic polyamide 6 (APA-6) is studied. Semi-empirical equations for the prediction of the APA-6 reaction kinetics and an advection equation for void transport are used in the numerical scheme. A complex numerical simulation of reactive injection of ε-caprolactam was developed for a three-dimensional industrial part. The validity of the approach is demonstrated for determining an effective injection strategy, including the position of vents and gates and the most effective parameter values for minimum mould filling time without the formation of voids.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research work is supported by the Spanish Ministry of Science and Innovation, project DPI2010-20333 and the Generalitat Valenciana through programme PROMETEO/2009/063.García Manrique, JA.; Hoto, R.; Gascón Martínez, ML.; Andrés De La Esperanza, FJ. (2014). A numerical simulation of woven/anionic polyamide 6 composite part manufacturing using structural reactive injection moulding process. Journal of Thermoplastic Composite Materials. 1-15. https://doi.org/10.1177/0892705714530746S115Van Rijswijk, K., Bersee, H. E. N., Jager, W. F., & Picken, S. J. (2006). Optimisation of anionic polyamide-6 for vacuum infusion of thermoplastic composites: choice of activator and initiator. Composites Part A: Applied Science and Manufacturing, 37(6), 949-956. doi:10.1016/j.compositesa.2005.01.023Van Rijswijk, K., van Geenen, A. A., & Bersee, H. E. N. (2009). Textile fiber-reinforced anionic polyamide-6 composites. Part II: Investigation on interfacial bond formation by short beam shear test. Composites Part A: Applied Science and Manufacturing, 40(8), 1033-1043. doi:10.1016/j.compositesa.2009.02.018Van Rijswijk, K., Lindstedt, S., Vlasveld, D. P. N., Bersee, H. E. N., & Beukers, A. (2006). Reactive processing of anionic polyamide-6 for application in fiber composites: A comparitive study with melt processed polyamides and nanocomposites. Polymer Testing, 25(7), 873-887. doi:10.1016/j.polymertesting.2006.05.006Van Rijswijk, K., & Bersee, H. E. N. (2007). Reactive processing of textile fiber-reinforced thermoplastic composites – An overview. 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Simulating the effect of temperature elevation on clamping force requirements during rigid-tool Liquid Composite Moulding processes. Composites Part A: Applied Science and Manufacturing, 43(12), 2221-2229. doi:10.1016/j.compositesa.2012.08.003Kabo, G. J., Kozyro, A. A., Krouk, V. S., Sevruk, V. M., Yursha, I. A., Simirsky, V. V., & Gogolinsky, V. I. (1992). Thermodynamic properties of 6-aminohexanoic lactam (ɛ-caprolactam). The Journal of Chemical Thermodynamics, 24(1), 1-13. doi:10.1016/s0021-9614(05)80249-6Marx, P., Smith, C. W., Worthington, A. E., & Dole, M. (1955). Specific Heat of Synthetic High Polymers. IV. Polycaprolactam. The Journal of Physical Chemistry, 59(10), 1015-1019. doi:10.1021/j150532a005Dole, M., & Wunderlich, B. (1959). Die Makromolekulare Chemie, 34(1), 29-49. doi:10.1002/macp.1959.020340102Kim, K. J., Kim, Y. Y., Yoon, B. S., & Yoon, K. J. (1995). Mechanism and kinetics of adiabatic anionic polymerization of ε-caprolactam in the presence of various activators. Journal of Applied Polymer Science, 57(11), 1347-1358. doi:10.1002/app.1995.070571111Malkin, A. Y., Ivanova, S. L., Frolov, V. G., Ivanova, A. N., & Andrianova, Z. S. (1982). Kinetics of anionic polymerization of lactams. (Solution of non-isothermal kinetic problems by the inverse method). Polymer, 23(12), 1791-1800. doi:10.1016/0032-3861(82)90124-0Camargo, R. E., Gonzalez, V. M., Macosko, C. W., & Tirrell, M. (1983). Bulk Polymerization Kinetics by the Adiabatic Reactor Method. Rubber Chemistry and Technology, 56(4), 774-783. doi:10.5254/1.3538154Teuwen, J. J. E., van Geenen, A. A., & Bersee, H. E. N. (2012). Novel Reaction Kinetic Model for Anionic Polyamide-6. Macromolecular Materials and Engineering, 298(2), 163-173. doi:10.1002/mame.201100457RUIZ, E., ACHIM, V., SOUKANE, S., TROCHU, F., & BREARD, J. (2006). Optimization of injection flow rate to minimize micro/macro-voids formation in resin transfer molded composites. Composites Science and Technology, 66(3-4), 475-486. doi:10.1016/j.compscitech.2005.06.013García, J. A., Gascón, L., Chinesta, F., Ruiz, E., & Trochu, F. (2010). An efficient solver of the saturation equation in liquid composite molding processes. International Journal of Material Forming, 3(S2), 1295-1302. doi:10.1007/s12289-010-0681-8Chui, W. K., Glimm, J., Tangerman, F. M., Jardine, A. P., Madsen, J. S., Donnellan, T. M., & Leek, R. (1997). Case Study from Industry:Process Modeling in Resin Transfer Molding as a Method to Enhance Product Quality. SIAM Review, 39(4), 714-727. doi:10.1137/s0036144596308546Gascón LL, García JA, Ruiz E, Modelling and prediction of saturation in liquid composite molding, submitted to publication, 2013[Please update Ref 21.]