Control de ganancias variables para robots de ngrados de libertad

En este artículo se aborda el problema de sintonía de ganancias variables para un controlador tipo proporcional derivativo más compensación de gravedad. Se presentan los datos obtenidos a partir del movimiento de los eslabones de un robot de tres grados de libertad tipo articular, de acuerdo a una ley de control de diseño que cumple las características de una función de Lyapunov, además de una función que sintoniza las ganancias del controlador proporcional derivativo de forma automática.Palabra(s) Clave(s): función de Lyapunov, ganancia variable, moldeo de energía

Red neuronal artificial para la extracción de parámetros dinámicos de robots a partir de información incompleta de su movimiento

The artificial neural networks are suitable for processing incomplete data to achieve the desired output. The acquisition system of the manipulator robots takes quantified samples of the position; therefore, it is not possible to execute deterministic algorithms of parameter extraction in a reasonable time. State of the art describes algorithms based on the assumption that the motion signals are not quantified, and the first and second derivatives of the position are sampled instead of estimated. In this paper, a trained neural network-based extraction parameter algorithm for a determined robot is proposed to reduce the robot characterization time. Also, with the proposed methodology is possible to extract the parameters of the same kind of robot used for training the neural network.Las redes neuronales artificiales son útiles para procesar datos con información incompleta para obtener una salida deseada. En los sistemas de medición de robots manipuladores, solo se toman muestras cuantificadas de la posición y, por lo tanto, no se puede ejecutar en un tiempo razonable algoritmos deterministas para extraer los parámetros del robot. En el estado del arte, se abordan algoritmos de extracción de parámetros basados en la suposición de que no existe la cuantificación de las señales del movimiento del robot y que la primera y segunda derivada de la posición son muestreadas y no estimadas. En este trabajo, se propone un algoritmo basado en una red neuronal entrenada para extraer los parámetros de un determinado robot para reducir el tiempo de caracterización del robot, además, con la metodología propuesta se pueden extraer parámetros dinámicos del mismo tipo de robot con el que se ha entrenado la red neuronal

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV

Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe

Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at root(NN)-N-S=2.76 TeV

Peer reviewe

Pseudorapidity and transverse-momentum distributions of charged particles in proton-proton collisions at root s=13 TeV

The pseudorapidity (eta) and transverse-momentum (p(T)) distributions of charged particles produced in proton-proton collisions are measured at the centre-of-mass energy root s = 13 TeV. The pseudorapidity distribution in vertical bar eta vertical bar <1.8 is reported for inelastic events and for events with at least one charged particle in vertical bar eta vertical bar <1. The pseudorapidity density of charged particles produced in the pseudorapidity region vertical bar eta vertical bar <0.5 is 5.31 +/- 0.18 and 6.46 +/- 0.19 for the two event classes, respectively. The transverse-momentum distribution of charged particles is measured in the range 0.15 <p(T) <20 GeV/c and vertical bar eta vertical bar <0.8 for events with at least one charged particle in vertical bar eta vertical bar <1. The evolution of the transverse momentum spectra of charged particles is also investigated as a function of event multiplicity. The results are compared with calculations from PYTHIA and EPOS Monte Carlo generators. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Elliptic flow of muons from heavy-flavour hadron decays at forward rapidity in Pb-Pb collisions at root s(NN)=2.76TeV

The elliptic flow, v(2), of muons from heavy-flavour hadron decays at forward rapidity (2.5 <y <4) is measured in Pb-Pb collisions at root s(NN)= 2.76TeVwith the ALICE detector at the LHC. The scalar product, two- and four-particle Q cumulants and Lee-Yang zeros methods are used. The dependence of the v(2) of muons from heavy-flavour hadron decays on the collision centrality, in the range 0-40%, and on transverse momentum, p(T), is studied in the interval 3 <p(T)<10 GeV/c. A positive v(2) is observed with the scalar product and two-particle Q cumulants in semi-central collisions (10-20% and 20-40% centrality classes) for the p(T) interval from 3 to about 5GeV/c with a significance larger than 3 sigma, based on the combination of statistical and systematic uncertainties. The v(2) magnitude tends to decrease towards more central collisions and with increasing pT. It becomes compatible with zero in the interval 6 <p(T)<10 GeV/c. The results are compared to models describing the interaction of heavy quarks and open heavy-flavour hadrons with the high-density medium formed in high-energy heavy-ion collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.Peer reviewe

Sistema de adquisición y transmisión de datos, por fibra óptica, para un generador de neutrones.

<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:HyphenationZone>21</w:HyphenationZone> <w:PunctuationKerning /> <w:ValidateAgainstSchemas /> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables /> <w:SnapToGridInCell /> <w:WrapTextWithPunct /> <w:UseAsianBreakRules /> <w:DontGrowAutofit /> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><!--[if !mso]><object classid="clsid:38481807-CA0E-42D2-BF39-B33AF135CC4D" id=ieooui></object> <style>&#13; st1:*{behavior:url(#ieooui) }&#13; </style> <![endif]--> <!-- /* Font Definitions */ @font-face {font-family:Times; panose-1:2 2 6 3 5 4 5 2 3 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:536902279 -2147483648 8 0 511 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; mso-bidi-font-size:10.0pt; font-family:Times; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"Times New Roman"; mso-ansi-language:EN-US; mso-fareast-language:ES;} p.Textonormal, li.Textonormal, div.Textonormal {mso-style-name:"Texto normal"; mso-style-parent:""; margin-top:0cm; margin-right:0cm; margin-bottom:4.0pt; margin-left:0cm; text-align:justify; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:ES; mso-fareast-language:ES;} p.Listnumbers, li.Listnumbers, div.Listnumbers {mso-style-name:"List numbers"; mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; text-align:justify; text-indent:0cm; mso-pagination:widow-orphan; mso-hyphenate:none; tab-stops:list 18.0pt; font-size:9.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-GB; mso-fareast-language:EN-US;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> <!--[if gte mso 10]> <style>&#13; /* Style Definitions */&#13; table.MsoNormalTable&#13; {mso-style-name:"Tabla normal";&#13; mso-tstyle-rowband-size:0;&#13; mso-tstyle-colband-size:0;&#13; mso-style-noshow:yes;&#13; mso-style-parent:"";&#13; mso-padding-alt:0cm 5.4pt 0cm 5.4pt;&#13; mso-para-margin:0cm;&#13; mso-para-margin-bottom:.0001pt;&#13; mso-pagination:widow-orphan;&#13; font-size:10.0pt;&#13; font-family:"Times New Roman";&#13; mso-ansi-language:#0400;&#13; mso-fareast-language:#0400;&#13; mso-bidi-language:#0400;}&#13; </style> <![endif]--> <p class="Listnumbers"><span style="font-size: 10pt; color: black;" lang="ES-MX">Se presenta el desarrollo construcción<span>   </span>y aplicación de un sistema virtual de adquisición de datos basado en el uso de microcontroladores, fibra óptica y PC; que restablece la comunicación entre los módulos básicos que componen un Generador de Neutrones. </span></p> <p class="Listnumbers"><span style="font-size: 10pt; color: black;" lang="ES-MX">Se muestra como queda modernizada la interfaz original del generador, al automatizarse la adquisición de datos sobre sus parámetros de explotación.</span></p> <p class="Listnumbers"><span style="font-size: 10pt; color: black;" lang="ES-MX"><span> </span>Se introduce el uso de la PC en el Generador de Neutrones y se establece el antecedente para extender la automatización a otros subsistemas de la instalación.</span></p> <p class="Textonormal"><span lang="ES"> </span></p

Design of a low cost measurement system based on accelerometers for gait analysis - doi: 10.4025/actascitechnol.v36i1.18581

Current research reports on the development of a portable electronic system to assess the kinematics of the lower limb joints at the sagittal plane. The electronic device characteristics and the different communication protocols to transfer data are also reported. Research obtained the hip and knee angles to analyze the lower limb kinematics during multiple gait cycles. Results showed that the movement patterns, found in the analysis made on people from central Mexico, were cyclical and alternating. The knee described a one third curve in flexion-extension movements just before the start of the flexion-extension curve in the swing phase. Moreover data obtained showed a correlation of movement between hip and knee during walking.