Publicaciones

Autores
Santiago, D.;

Resumen:
El tema de la presente tesis doctoral se centra en el área de control automático, más específicamente en los sistemas de teleoperación bilateral de robots móviles.Las principales contribuciones de esta tesis son:1.Algoritmos de control orientados a la teleoperación bilateral estable de robots móviles no-holonómicos terrestres con retardos de comunicación.2.Esquemas de control que mejoran la transparencia de los sistemas de teleoperación.3.Esquemas de teleoperación bilateral de manipuladores móviles no holonómicos terrestres.4.Interfaces hápticas para teleoperación de manipuladores móviles y análisis de los efectos de su uso.5.Esquema de teleoperación bilateral de robots aéreos de tipo cuadricóptero.6.Teoría de teleoperación multipunto en la que la red de teleoperación puede estar constituida por múltiples dispositivos maestros y esclavos, que pueden ser robots móviles, manipuladores, manipuladores móviles o sub-sistemas virtuales automáticos.7.Análisis de estabilidad de los diferentes sistemas propuestos.8.Evaluación del rendimiento y la transparencia de los esquemas propuestos a través de experimentación y simulaciones.9.Herramientas de software de libre acceso enfocadas en el desarrollo rápido y simple de sistemas robóticos para su utilización en el campo académico y educativo.

Autores
Veca, A.;

Resumen:
Esta obra está orientada a lectores con preparación universitaria interesados en conocer los principios físicos y aplicaciones del ultrasonido en las área industrial, haciendo hincapié en los Ensayos no Destructivos, y en el área de la biología y medicina. Es una síntesis de los cursos de Aplicaciones Industriales del Ultrasonido y Ultrasonido para uso Médico, dictados por el autor en la Facultad de Ingeniería de la Universidad Nacional de San Juan. Está compuesta de 7 temas que abarcan entre otros, principios físicos, transductores y lentes acústicas, métodos de emisión y recepción, modelado de la seña de eco, métodos de registros, arrays ultrasónicos y focalización electrónica, efecto Doppler aplicado a la medicina, ultrasonido de potencia y sonar. A lo largo de la obra se hace especial hincapié en los métodos y técnicas para las diferentes aplicaciones. También se introduce al lector a las herramientas actuales de simulación a fin de poder acceder rápidamente, a la obtención de resultados tanto en la etapa de estudio como en la estimación de parámetros en la etapa de diseño.

Autores
Correa, J.;

Resumen:
El objetivo de esta Tesis Doctoral es hacer aportes sobre la estimación de velocidad y variaciones de resistencia rotórica en los motores de inducción trifásicos. Este trabajo se desarrolla en seis capítulos en la siguiente secuencia: introducción, modelo del motor de inducción, estado del arte en la técnica de estimar la velocidad de estos motores, propuesta para estimar la velocidad, propuesta para determinar variaciones de la resistencia rotórica y conclusiones. De estos temas, los más relevantes por sus aportes originales son tres: el modelo del motor, la propuesta para estimar la velocidad y la propuesta para estimar variaciones de resistencia rotórica. Por tal motivo, estos tres temas son los que se describen sucintamente a continuación: El modelo del motor de inducción trifásico que se desarrolla en esta tesis, permite el análisis del comportamiento dinámico de las corrientes del estator y del rotor. El modelo que se presenta está compuesto por dos partes: una lineal y otra no lineal. La parte lineal describe el comportamiento de las variables eléctricas de la máquina y la parte no lineal realiza la misma función, pero para las variables mecánicas. Esta partición es posible porque la dinámica de ambos tipos de variables es muy diferente. Las variables eléctricas varían mucho más rápido que la velocidad del motor, por lo tanto, esta se puede considerar constante en un periodo mucho menor que la constante de tiempo mecánica. En estas condiciones, la velocidad es un parámetro que se actualiza en el modelo lineal desarrollado en espacio de estados. De esta forma se obtiene un modelo completo del motor de inducción en base a los parámetros eléctricos y mecánicos estándar. La propuesta para estimar la velocidad, se basa en una propiedad que tienen las corrientes de estator y rotor cuando se produce un transitorio en la alimentación. Esta propiedad establece que la suma de las pulsaciones angulares de las corrientes de estator y rotor es igual a la velocidad angular eléctrica del eje del motor. Esta relación se demuestra analíticamente con herramientas de cálculo simbólico y se verifica experimentalmente en ensayos. El método propuesto para estimar las variaciones de la resistencia rotórica se basa en analizar el comportamiento de la tensión de estator cuando estando en funcionamiento el motor, se le interrumpe la energía por un breve intervalo. Durante este tiempo, el motor pasa a funcionar como generador gracias a la energía acumulada en la inductancia del rotor y en las masas rotantes. En este transitorio, el rotor induce una tensión en las bobinas de estator. Esta tensión tiene una relación directa con la corriente del rotor que, a su vez depende de los elementos pasivos del circuito. La evolvente de la tensión generada en el estator refleja la variación de la corriente del rotor en el transitorio. Comparando la evolvente en dos estados de funcionamiento, se puede determinar en qué relación ha variado la resistencia rotórica. Esta propuesta se demuestra analíticamente con herramientas de cálculo simbólico, se explica físicamente lo que ocurren en la máquina y se verifica experimentalmente mediante ensayo.

Autores
Salinas, L.; Santiago, D.; Slawiñski, E.; Mut, V.;Danilo Chavez ;Paulo Leica ;Oscar Camacho ;

Resumen:
This paper proposes a control scheme based on combining a PD-like structure and a sliding mode control (SMC) applied to mobile robot bilateral teleoperation systems, in the face of asymmetric and time-varying delays. The proposal includes on the remote site both a P+d control and a SMC strategy in such a way that the advantages of both methods are exploited. The system stability is analyzed using Lyapunov-Krasovskii functionals and a delay-dependent stability criteria is obtained using linear-matrix-inequalities (LMI). Finally, the teleoperation system is evaluated through human-in-the-loop experiments to confirm the theoretical results and test the robustness and stability of the proposed control scheme.

Autores
Herrera, D.; Roberti, F.; Carelli, R.;Victor Andaluz ;José Varela ;Jessica Ortiz ;Paúl Canseco ;

Resumen:
This work presents the kinematic and dynamic modeling of a human–wheelchair system which considers that its center of mass is not located in the middle of the wheel's axle. Furthermore, a novel motion controller is presented for a human–wheelchair system, which is capable of performing positioning and path-following tasks in human-shared environments. This controller design is based on two cascaded subsystems: a kinematic controller, and a dynamic controller that compensates the dynamics of the human–wheelchair system. Additionally, an algorithm based on fuzzy-logic is proposed and incorporated in the aforementioned path-following control for pedestrian collision avoidance. This methodology considers to quantify heuristics social rules to make a balance between modulating velocity or direction during the avoidance. Three di®erent interference cases, commonly found during walking events, are tested in a structured scenario. The experimental results demonstrate that the system is capable of overcomingmany usual interference situations with human obstacles. A good performance of the path-following control is also verified.

Autores
Gimenez, J.; Gandolfo, D.; Salinas, L.; Rosales, C.; Carelli, R.;

Resumen:
A novel kinematic formation controller based on null-space theory is proposed to transport a cable-suspended payload with two rotorcraft UAVs considering collision avoidance, wind perturbations, and properly distribution of the load weight. An accurate 6-DoF nonlinear dynamic model of a helicopter and models for flexible cables and payload are included to test the proposal in a realistic scenario. System stability is demonstrated using Lyapunov theory and several simulation results show the good performance of the approach.

Autores
Gimenez, J.; Amicarelli, A.; Toibero, M.; di Sciascio, F.; Carelli, R.;

Resumen:
This paper models the complex simultaneous localization and mapping (SLAM) problem through a very flexible Markov random field and then solves it by using the iterated conditional modes algorithm. Markovian models allow to incorporate: any motion model; any observation model regardless of the type of sensor being chosen; prior information of the map through a map model; maps of diverse natures; sensor fusion weighted according to the accuracy. On the other hand, the iterated conditional modes algorithm is a probabilistic optimizer widely used for image processing which has not yet been used to solve the SLAM problem. This iterative solver has theoretical convergence regardless of the Markov random field chosen to model. Its initialization can be performed on-line and im- proved by parallel iterations whenever deemed appropriate. It can be used as a post-processing methodology if it is initialized with es- timates obtained from another SLAM solver. The applied methodology can be easily implemented in other versions of the SLAM prob- lem, such as the multi-robot version or the SLAM with dynamic environment. Simulations and real experiments show the flexibility and the excellent results of this proposal.

Autores
Gimenez, J.; Tosetti, S.; Salinas, L.; Carelli, R.;

Resumen:
Spatial awareness and memory are key factors for a robot to evolve in semi-structured and dynamic environments as those found in agriculture, and particularly in fruit crops where the trees are regularly distributed. This paper proposes a probabilistic method for mapping out-of-structure objects (weeds, workers, machines, fallen branches, etc) using a Kernel density estimator. The methodology has theoretical and practical advantages over the well-known occupancy grid map estimator such as optimization of storage resources, online update, high resolution, and straightforward adaptability to dynamic environments. An example application would be a control scheme through which a robot is able to perform cautious navigation in areas with high probability of finding obstacles. Simulations and experiments show that large extensions can be online mapped with few data and high spatial resolution.

Autores
Ana Cecilia Villa-Parra ;Denis Delisle-Rodriguez ;Thomaz Botelho ;John Jairo Villarejo Mayor ;Alberto López Delis ; Carelli, R.; Frizera Neto, A.; Freire Bastos, T.;

Resumen:
Introduction: This work presents the development of a novel robotic knee exoskeleton controlled by motion intention based on sEMG, which uses admittance control to assist people with reduced mobility and improve their locomotion. Clinical research remark that these devices working in constant interaction with the neuromuscular and skeletal human system improves functional compensation and rehabilitation. Hence, the users become an active part of the training/rehabilitation, facilitating their involvement and improving their neural plasticity. For recognition of the lower-limb motion intention and discrimination of knee movements, sEMG from both lower-limb and trunk are used, which implies a new approach to control robotic assistive devices. Methods A control system that includes a stage for human-motion intention recognition (HMIR), based on techniques to classify motion classes related to knee joint were developed. For translation of the user’s intention to a desired state for the robotic knee exoskeleton, the system also includes a finite state machine and admittance, velocity and trajectory controllers with a function that allows stopping the movement according to the users intention. Results The proposed HMIR showed an accuracy between 76% to 83% for lower-limb muscles, and 71% to 77% for trunk muscles to classify motor classes of lower-limb movements. Experimental results of the controller showed that the admittance controller proposed here offers knee support in 50% of the gait cycle and assists correctly the motion classes. Conclusion The robotic knee exoskeleton introduced here is an alternative method to empower knee movements using sEMG signals from lower-limb and trunk muscles.

Autores
Luis A. Clementi ;Romina B. Suvire ; Rossomando, F.;Jorge R. Vega ;

Resumen:
To improve the quality of industrial nitrile rubbers, the copolymer chemical composition, pA(t), should ideally be kept constant along the reaction. This work proposes a closed-loop control strategy for the semibatch operation of the reactor with the aim of regulating pA(t) within a reduced range of variability. The proposed strategy is evaluated by simulating a mathematical model of the process. To this effect, a simplified mathematical model of the reaction is first derived and then utilized to obtain a suboptimal control law and a softsensor that estimates the polymerization rates. The suboptimal control law is compensated by adding a term proportional to errors in pA(t). The simulated example considers the production of the low-composition AJLT grade, with the copolymerization reaction represented by a detailed mathematical model adjusted to an industrial plant. Due to the high performance of the softsensor, the simulation results suggest that the proposed closed-loop strategy is efficient to adequately regulate pA(t) in spite of structural and parametric uncertainties, while other quality variables remained practically unaffected.

Autores
Rossomando, F.; Soria, C.; Freire, E.; Carelli, R.;

Resumen:
It is well known that all robotic systems have additional dynamics and disturbances beyond those that are modelled. Hence, in this paper, the performance of a neuro-adaptive sliding mode control (NA-SMC) controller is analysed in the presence of disturbances and unmodelled dynamics. The proposed control strategy has two stages: first, a feedback linearization controller for a kinematic model; second, a neuro-adaptive SMC controller for a dynamic model. The entire control strategy is designed in discrete time using Lyapunov’s criterion, and the stability problems caused by direct implementation in discrete time to a system designed in a continuous domain are thereby avoided. The unmodelled dynamics introduce tracking errors in the closed-loop system; however, experiments made using the proposed approach to control mobile robots show that output tracking error tends to zero.

Autores
Garcia, S.; Slawiñski, E.; Mut, V.; Penizzotto, F.;

Resumen:
This paper proposes a collision avoidance method for the teleoperation of multiple non-holonomic mobile robots from multiple users. Each human operator drives a mobile robot, where each one performs an independent task in a common workspace. To avoid collisions, the proposed method only acts on the speed of the mobile robots; therefore, the human operator can freely drive the robot over the path he chooses to. The developed analysis allows us to assure that a solution is always achieved. Finally, the results of the experiments are shown, in order to test the performance of the proposed control scheme.

Autores
Freire, E.; Rossomando, F.; Soria, C.;

Resumen:
In this paper a MIMO (Multiple-Input-Multiple-Output) adaptive neural PID (AN-PID) controller that can be applied to a nonlinear dynamics is proposed, and its use is shown in the control of a SCARA robot for two degrees of freedom. The AN-PID controller, including a neural network of the dynamic perceptron type, is designed. The proposed controller uses a RBF network to identify the model and back propagates the control error to the AN-PID controller, unlike other controllers, that use direct methods to back propagate such error. With these properties, an AN-PID controller corrects the tracking errors due to the uncertainties and variations in the robot arm dynamics. It is robust and with adaptive capacity in order to achieve a suitable control performance. Experimental results on the SCARA robot were obtained to illustrate the effectiveness of the proposed control strategy, including comparison with a classical PID. By using Lyapunov's discrete-time theory, it was demonstrated that the control error is semi-global uniformly ultimate bounded (SGUUB).

Autores
M. Cecilia Fernández ; , S.;M. Nadia Pantano ; Ortiz, O.; Patiño, D.; Scaglia, G.;

Resumen:
This paper proposes a new control law based on linear algebra. This technique allows nonlinear path tracking in multivariable and complex systems. This new methodology consists in finding the control action to make the system follow predefined concentration profiles solving a system of linear equations. The controller parameters are selected with a Monte Carlo algorithm so as to minimize a previously defined cost index. The control scheme is applied to a fed-batch penicillin production process. Different tests are shown to prove the controller effectiveness, such as adding parametric uncertainty, perturbations in the control action and in the initial conditions. Moreover, a comparison with other controllers from the literature is made, showing the better performance of the present approach.

Autores
Serrano, E.;Sebastián Godoy ; Gandolfo, D.; Mut, V.; Scaglia, G.;

Resumen:
The paper presents a nonlinear control law for a marine vessel to track a reference trajectory. In the wake of the results obtained in [19], an integrative approach is incorporated in the linear algebra methodology in order to reduce the effect of the uncertainty in the tracking error. This new approach does not increase the complexity of the design methodology. In addition, the zero convergence of tracking error under polynomial uncertainties is demonstrated. Simulation results under environmental disturbance and model mismatches are presented and discussed.

Autores
Capraro Fuentes, F.; Tosetti, S.; Rossomando, F.; Mut, V.; Vita Serman, F.;

Resumen:
This article presents a description of the design, development, and implementation of web-based software and dedicated hardware which allows for the remote monitoring and control of a drip irrigation system. The hardware consists of in-field stations which are strategically distributed in the field and equipped with different sensors and communication devices; a weather station and drip irrigation system complete the setup. The web-based software makes it possible to remotely access and process the information gathered by all the stations and the irrigation controller. The proposed system was implemented in a young olive orchard, located in the province of San Juan, an arid region of Argentina. The system was installed and evaluated during the seasons 2014–2015 and 2015–2016. Four regulated irrigation strategies were proposed in the olive orchard to test its behavior. In this pilot experiment, the precision irrigation system was a useful tool for precisely managing the irrigation process, applying only the required amount of water (precise irrigation). Regulated deficit irrigation experiments, on the other hand, have demonstrated the sensitivity of olives to water restriction. The precision irrigation system made it possible to control soil moisture levels, avoiding water stress in the control treatment.

Autores
Accolti, E.; di Sciascio, F.;

Resumen:
How is an acoustically diffuse field defined? To what extent are the equations of diffuse field theory valid? These are the questions addressed in this presentation. The answers are explained through more general theories, in turn explained with figures. The starting point is the idealization of diffuse sound field, from where the basic calculation tools used in architectural acoustics are derived. Then, we go through the physical-mathematical models of wave theory and ray theory assuming diffuse field simplifications and analyze the scope of diffuse field models. Wave models and ray models are presented in a simple format with visual support and reference to the underlying mathematical models. The criteria used to define a diffuse field in frequency domain as well as in temporal domain are analyzed. Finally, we present a review of several state of the art tools used to address the real cases when diffuse field cannot be assumed.

Autores
Herrera, D.; Gimenez, J.; Monllor, M.; Roberti, F.; Carelli, R.;

Resumen:
Social behaviors are crucial to improve the acceptance of a robot in human-shared environments. One of the most important social cues is undoubtedly the social space. This human mechanism acts like a repulsive field to guarantee comfortable interactions. Its modeling has been widely studied in social robotics, but its experimental inference has been weakly mentioned. Thereby, this paper proposes a novel algorithm to infer the dimensions of an elliptical social zone from a points-cloud around the robot. The approach consists of identifying how the humans avoid a robot during navigation in shared scenarios, and later use this experience to represent humans obstacles like elliptical potential elds with the previously identied dimensions. Thus, the algorithm starts with a rst-learning stage where the robot navigates without avoiding humans, i.e. the humans are in charge of avoiding the robots while developing their tasks. During this period, the robot generates a points-cloud with 2D laser measures from its own framework to dene the human-presence zones around itself but prioritizing its closest surroundings. Later, the inferred social zone is incorporated to a null-space-based (NSB) control for a non-holonomic mobile robot, which consists of both trajectory tracking and pedestrian collision avoidance. Finally, the performance of the learning algorithm and the motion control is veried through experimentation.

Autores
Salinas, L.; Gimenez, J.; Rosales, C.; Gandolfo, D.;

Resumen:
This paper considers the problem of carrying a payload hanging through flexible cables from rotorcraft unmanned aerial vehicles (RUAVs), taking into account obstacle avoidance, even distribution of payload weight between the aircrafts, and formation shape. The simultaneous fulfillment of these objectives, prioritizing obstacle avoidance, is achieved by using a null-space-based control. In this approach the payload must follow a predetermined path to avoid possible oscillations. In addition, an accurate 6-DoF nonlinear dynamic model of a mini-helicopter and dynamic models for the cables and payload are included to consider a realistic scenario. Finally, simulation results show the good performance of the proposed approach.

Autores
Paes Santos, M.; Sarcinelli-Filho, M.; Santos Brandao, A.; Carelli, R.;

Resumen:
In this work a novel control architecture is proposed to guide an Unmanned Aerial Vehicle (UAV), specifically a quadrotor, in 3D flights correspondent to positioning and path-following tasks. Such an architecture is based on the fusion of three control signals generated by three simpler controllers (associated to PVTOL tasks). Considering the whole navigation as a task composed by the control of the vehicle orientation with respect to its target (associated to a Z-PVTOL controller), the control of its forward movement (associated to a XZ-PVTOL controller), and the correction of any side displacement (associated to a YZ-PVTOL controller, similar to the XZ-PVTOL controller), a first approach was to execute such partial maneuvers one each time, using the same three PVTOL controllers here adopted, switching from one to other of these controllers according to a supervisor. The new approach adopted in this paper corresponds to consider that the three PVTOL controllers act simultaneously, and generating the final control signal to be sent to the UAV through fusing the individual control signals generated by the PVTOL controllers, thus smoothly coupling three simpler controllers. Experimental results are presented to validate the proposed approach, and the performance of the controller thus designed is compared to the one correspondent to the switching approach.

Autores
Rosales, C.; Rossomando, F.; Soria, C.; Carelli, R.;

Resumen:
This paper proposes a neuro-adaptive controller with supervisory control for UAVs. A state observer of the control errors is defined because the vehicle could be affected by measurement noise and external disturbances. In this study, the control errors are estimated by a state neural observer from which the neural adaptive system generates a control action. Also, a supervisor term is defined in order to guarantee the system stability. The neuro-adaptive controller parameters are updated on-line by the adjustment laws that are a function of the control errors calculated by the observer. These adjustment laws were obtained through the Lyapunov stability criterion. To summarize, simulation results demonstrate the good performance of the proposed technique for trajectory tracking tasks in navigation environments affected by measuring noise and external disturbances.

Autores
Francisco Raverta Capua ; Sansoni, S.;Marcelo L. Moreyra ;

Resumen:
Argentinian fruit activity has been in crisis in the late years due to several factors, including the shortage of workers and high costs associated to the production.The development and incorporation of new tecnologies in order to automate and enhance the productive processes are urgent and unavoidable. In this line, this work is framed in the development of an autonomous navigation system based or artificial vision for a fruit platform for pruning and harvest labors. In particular, an experimental evaluation of VisualSLAM strategies for stereo cameras applied to the estimation of the trayectory of a self-propelled platform in a typical fruit environment of the Patagonia region is presented. This proposal analyses the performance of 3 well-known publically available methods of the state-of-the-art, in order to conclude about their applicability in this particular environment. The results are based on image sequences captured in the installations of INTA Alto Valle (Instituto Nacional de Tecnología Agrícola Alto Valle) in real light and weather conditions, and

Autores
Accolti, E.; di Sciascio, F.;

Resumen:
Desde los inicios de la acústica de salas como una rama científica de la acústica los investigadores del área han desarrollado descriptores acústicos mesurables que puedan estar correlacionados con las características constructivas de las salas. En los últimos 120 años se han ido desarrollando dos grandes grupos de descriptores, por un lado, los descriptores objetivos que se pueden determinar mediante mediciones físicas acústicas tales como el nivel sonoro y, por otro lado, los descriptores subjetivos que reflejan la percepción de cada sujeto y se pueden determinar mediante encuestas o mediciones fisiológicas. Los descriptores objetivos se pueden relacionar con aspectos arquitectónicos de las salas y los descriptores subjetivos son los que más fielmente reflejan la calidad acústica. Por esa razón, la búsqueda de descriptores objetivos que se relacionen con los parámetros subjetivos permite comprender mejor cómo los elementos del diseño arquitectónico influyen en la percepción del sonido y, a su vez, en la calidad acústica de la sala. Pätynen y Lokki (2016) han estudiaron perceptualmente, mediante encuestas en laboratorio, la influencia de seis salas de concierto en la percepción de contrastes dinámicos. Para este fin usaron un pasaje del movimiento II de la Sinfonía N. 8 de Brukner (el pasaje se compone de los compases 41-43 seguidos por los compases 53-55) y simularon digitalmente el comportamiento de las salas. Esto les permitió, mediante comparación pareada de los estímulos, encontrar la relación entre la percepción del rango dinámico de la sala y el contraste de otros parámetros subjetivos cómo la sonoridad, la reverberancia, el ancho aparente del escenario, el brillo y el balance de bajos entre otros. Además, encontraron que hay una gran relación entre los resultados subjetivos y la calidad acústica de estas salas de concierto. También estudiaron la relación con parámetros objetivos existentes sin encontrar una relación significativa. En el presente proyecto se estudian posibles descriptores objetivos que puedan tener relación con este descriptor subjetivo estudiado por Pätynen, J., y Lokki. Se presenta el estado de avance de este proyecto incluyendo algunos resultados preliminares que avalan la hipótesis de que existan descriptores objetivos relacionados con la percepción de los contrastes dinámicos de salas para música no amplificada.

Autores
Sarapura, J.; Roberti, F.; Sebastián, J.; Carelli, R.;

Resumen:

Autores
Cristian Rodríguez Rivero ; Pucheta, J.;Paula Otaño ;Gustavo Juárez ;Leonardo Franco ; Patiño, D.;Raoul Velazco ;

Resumen:
We propose a new ensemble forecasting method, Bayesian enhanced ensemble approach (BEEA), to model neural networks for time series forecasting. Motivated by looking to get better prediction algorithms, our proposed algorithm can effectively integrate the data from different methods modified by Bayesian learning. A dataset of univariate time series (seasonal and non-seasonal) is used to forecast short-long prediction horizons, mainly 3 and 18 out-of-sample. Comparative simulations of our method with ten existing linear and nonlinear forecasting approaches, namely, Energy associated to series (EAS), Energy associated to series modify by Renyis's entropy (EASmod), Bayesian approach (BA), Bayesian enhanced (BEA), Bayesian enhanced modified by Renyi's entropy (BEMA), Bayesian enhanced modified by relative entropy (BEAmod.) is presented. Relative advantages and limitations of the ensemble approach in contrast with some reported in the literature illustrates the effectiveness of the Bayesian enhanced ensemble approach (BEEA) through different forecasting horizons in both, the learning process and the validation test using the MASE, SMAPE and RMSE forecast error metrics to highlight the performance and limitations of the BEEA approach.

Autores
Veca, A.;

Resumen:
El trabajo parte del análisis de la detección de una perturbación hidroacústica captada por un arreglo de sensores ubicados a una profundidad de 850 metros y a una distancia de 6.500 km de la fuente, indicando la presencia de una emisión acústica y de dos ecos. La fuente que estaba sumergida a una profundidad aproximada no inferior a 40 metros fue de tipo monopolar, omnidireccional e impulsiva de muy baja frecuencia. El estudio consistió en extraer la información brindada por los sensores que captaron la emisión y de la información de los mismos, como consecuencia de una calibración consistente en una detonación controlada en el mismo lugar donde se ubicó la fuente bajo estudio. Con esta información se realizó un cálculo teórico para estimar atenuación de la energía acústica de un frente de onda cilíndrico que se traslada en el entorno del eje del canal sonoro profundo SOFAR. El estudio se completa con la estimación de la energía liberada por la fuente. Al final, se propone un modelo para estudiar lasecuencia temporal completa de la señal acústica recibida.

Autores
Monllor, M.; Roberti, F.; Carelli, R.;

Resumen:
Due to the increase number of people with disabilities, new solutions are needed to be able to assist them in their daily life and thus improve their living conditions. In the present work, an admittance controller is proposed for assistance robots sensitive to obstacles, focused on people with diminished visual capacities. The objective of the controller is to modify the damping parameter as a function of nearby objects to provide a haptic feedback to the user and allow him to approach the target object at a safe speed. The results in the simulation show the operation of the controller. Simulations are performed to observe specific behaviors of the controller and tests are carried out with a real robot. The results were satisfactory, the controller showed a good performance in detecting obstacles and allowing a safe approach through haptic feedback to the user.

Autores
MORALES, H.; di Sciascio, F.; Amicarelli, A.;

Resumen:
Supersaturation is a fundamental variable in the crystallization processes in the chemical and food industry. This variable cannot be measured online, for this reason a state estimator is proposed to approximate its value in the single effect evaporators of the sugar industry. The designed estimator is based on the use of artificial neural networks and validated by comparing the approximate variable with the theoretical data of the process. The results provide a satisfactory estimate, presenting an average error of 0.1%, acceptable for the process.

Autores
Sarapura, J.; Roberti, F.; Gimenez, J.; Patiño, D.; Carelli, R.;

Resumen:
In this paper we present a new adaptive dynamic controller based on vision for tracking objects with a planar manipulator robot in fixed camera configuration, considering the orientation of the camera assembly, the depth of the object and the dynamic parameters of the robot to be uncertain. The control scheme is designed with a vision-based adaptive kinematic controller in charge of executing the task of tracking the object even with unknown parameters of the vision system. This controller provides speed references to a dynamic cascade adaptive controller whose objective is to generate the final control actions of the robot with imprecise knowledge of its dynamics. Finally, it is shown the stability of the proposed system based on the Lyapunov Theory and the performance of the two adaptive controllers through simulations are shown.

Autores
Gomez Olivares, J.; Capraro Fuentes, F.; Soria, C.; Peña, M.;

Resumen:
In modern agriculture, the efficient use of water for irrigation is essential for the development and sustainability of agricultural undertakings. In order to do so, this paper presentsthe design of an irrigation controller based on a water movement model in the soil that allows knowing the moisture value at different depths. A model-based predictive control strategy is proposed to determine the operation of the irrigation valves, taking into account the system constraints (maximum input flow, maximum and minimum water content levels, irrigation requirements); In this way, the controller determines the times to start the irrigation and the amount of water to be supplied through a drip irrigation system. At first instance, the functioning of the predictive control algorithm is evaluated without taking into account the extraction of water, either by evaporation or by the consumption of some type of crop.

Autores
Moya González, V.; Slawiñski, E.; Mut, V.;

Resumen:
This paper presents a control scheme to teleoperate the forward speed of a bipedal robot. The robot's model used represents a underactuated system of 5 degrees of freedom and is implement in Matlab/SimMechanics. The references given to each joint are inspired by the way people walk, while the control mechanism is based on a dynamic compensation that uses the generating data by a P+d controller and a neural network that identifies the plant, these elements together improve the biped walk. In addition, simulation's results are shown to evaluate the operation of the proposed scheme.

Autores
Rodolfo Rodrigo ; Patiño, D.;Gustavo Schweickardt ;

Resumen:
Sensors play a critical role monitoring processes and control of infrastructure. These together with the adaptation, calibration and signal transmission devices conform measurement devices that operate in a control and monitoring loop, are essential for the correct operation of various industrial production systems. A disarrangement of such devices as a whole and eventual failure, are expressed in deviated measurements of expected values that an operator can detect. Therefore, it is necessary to have algorithms that can offer an early warning when the dynamics of a system does not correspond to the measured values. In this sense, this document proposes two approaches. A forecasting technique based on series of past temporary data, which uses an autoregressive model of integrated moving average (ARIMA) and another based on a neuronal network of the multilayer Perceptron type. For both cases, a 95% prediction interval was established to set a criterion to detect anomalies and issue a warning of failure of the measuring device. Both methods were compared to issue an alert, in industrial temperature measurement systems.

Autores
Capraro Fuentes, F.; Tosetti, S.; Mut, V.;

Resumen:
Los sistemas de telemetría permiten la monitorización y control remoto de procesos a grandes distancias; la implementación en la agricultura es reciente y demuestra importantes ventajas. En el trabajo se presenta el desarrollo de un sistema de Telemetría Agrícola conformado por de estaciones de medición (fijas y móviles) que se instalan dentro de la zona cultivada; en combinación con de una serie de módulos informáticos encargados de procesar los datos de campo (estación base), el sistema permite disponer de información en tiempo real sobre la evolución del cultivo, la gestión del riego y condiciones del clima. Se presenta una descripción de cada componente del sistema para el cual se integraron tecnologías en electrónica, comunicación, informática robótica y control automático. El desarrollo incluyó el diseño de un entorno visual para que los usuarios consulten la información y gestionen las operaciones del riego de manera precisa en base a la demanda hídrica del cultivo, entre otros requerimientos. Finalmente se presenta un ensayo sobre una parcela de tomate en la que se aplicaron tres tratamientos de riego diferenciados.

Autores
Tosetti, S.; Capraro Fuentes, F.; Soria, C.;Emiliano Aubone ;Javier Mulet ;

Resumen:
En este trabajo se presenta el diseño e implementación de un sistema prototipo para la medición de temperatura foliar sin contacto, para el relevamiento georeferenciado y automático del estado de las plantas. El sistema se ha implementado teniendo como premisa la utilización de elementos de bajo costo. Para la medición de temperatura sin contacto se ha diseñado un arreglo lineal de sensores de tipo infrarrojo, los cuales han sido montados en un vehículo terrestre autónomo. Para la geolocalización se ha desarrollado un GPS diferencial, utilizando módulos GPS de bajo costo y la librería RTKLib. Se presentan los resultados obtenidos con este prototipo y se proponen algunas mejoras a tener en cuenta para futuras versiones.

Autores
Veca, A.;

Resumen:
El trabajo parte del análisis de los datos captados y procesados por una de las estaciones internacionales de monitoreo de explosiones nucleares. Estas estaciones subacuáticas, 11 en total, que se encuentran ubicadas estratégicamente, obtienen información sensorial de naturaleza diferente. Por un lado, mediante un arreglo acústico sumergido a una profundidad del orden de los 800 metros, reciben información sonora de muy baja frecuencia (infrasonidos). Por otro, disponen de sensores sensibles a ondas T- phase a fin de obtener información sobre terremotos. A partir de lo anterior, se analiza una perturbación acústica captada por el arreglo de sensores pertenecientes a la estación HA10 ubicada en las cercanías de la isla Ascensión, situada a una distancia de 6.500 km de la fuente, indicando la presencia de una emisión acústica y de dos ecos. La fuente que estaba sumergida a una profundidad aproximada de 40 metros se la modela como un monopolo omnidireccional e impulsivo de muy baja frecuencia. El estudio consistió en modelar el trayecto de la energía acústica y determinar las posibles reflexiones y refracciones a lo largo del trayecto. Se analizaron los diferentes modelos de canales subacuáticos posibles, llegando a la conclusión de que el que mejor se ajusta a los registros es el comprendido entre la termoclima estacional y el eje del canal sonoro profundo. El estudio se completa con la estimación de la energía liberada por la fuente en función de las atenuaciones impuestas en el trayecto por el medio, demostrándose que el conjunto de estaciones puede detectar y procesar información sensorial de suma importancia para casos que no se consideraron en su concepción.

Autores
Bocca, P.; Soria, C.; Carelli, R.;

Resumen:
Abstract— Adaptive robotic arm for the application of liquids for foliar action treatments. In the present work, the study of the operation and control of a mechanical arm with adaptable configuration for the positioning of nuzzles for the application of liquid products with foliar action at the optimum operating distance is presented. This system consists of a motorized arm with adaptable configuration to the variable geometry of the canopies of the trees, to optimally positioned nozzles for the application of foliar action fluids, as pesticide agent for the control of pests, fertilizers, etc. The objective of the controller is to generate references that allow the robot to acquire the shape of an olive tree profile to dose the desired product.