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

COORDINACIÓN DE DOS DRONES MEDIANTE UN SENSOR DE ALTITUD/ORIENTACIÓN MONOCULAR (COORDINATION OF TWO DRONES THROUGH AN ALTITUDE/ORIENTATION MONOCULAR SENSOR)

En este trabajo se describe la coordinación entre dos drones: un cuadri-rotor (dron esclavo) y un tri-rotor (dron maestro) este último con movimiento de inclinación en los motores. Este movimiento especial será usado para hacer control de seguimiento. Se presenta un consensus de vuelo en desplazamiento no holonómico del dron maestro en términos de posición y ángulo. El dron maestro es controlado utilizando una PC mediante dos transceptores RF con los que se reciben las ganancias de control y las posiciones deseadas. En el dron esclavo se precargan las ganancias de control y únicamente se tienen los valores de referencia la distancia entre drones ( ) y la posición  en el plano de la imagen. Se pretende simular un sistema de tren aéreo usando una cámara por dron esclavo mediante el uso de un algoritmo de cuatro puntos para detectar los ángulos de Euler y la posición cartesiana en el plano de la imagen de la cámara. Finalmente se muestran las gráficas en la sección de resultados, donde se analizarán las respuestas de control utilizando la cámara y sin ella.Palabra(s) Clave: Control, Visión, Robótica. AbstractIn this paper it is described the coordination between two drones: one quadrotor (slave) and one trirotor (master) with tilt movement in the motors. This special movement of the first will be used to make a tracking control. The paper presents a non-holonomic displacement towards a consensus in flight and in terms of the position and the angle. The master drone is controlled via Radio Frequency (RF) with two transceptors using a PC who gives the syntonization parameters for the drone and the desired positions. The slave drone have preloaded the control parameters and the control inputs are the desired positions  and  the distance between drones. In this work, we pretend simulate an aerial train system using a camera per drone slave through the detection of four points to get the Euler angles and the Cartesian position from the camera. Finally the graphs of responses are showed in the results, where is analyzed the control responses using the camera and without it.Keywords: Control, Vision, Robotics

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

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

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

Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

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