Publicaciones

Autores
Santiago Rómoli ;Mario Serrano ; Rossomando, F.;Jorge Vega ; Ortiz, O.; Scaglia, G.;

Resumen:
The lack of online information on some bioprocess variables and the presence of model and parametric uncertainties pose significant challenges to the design of efficient closed-loop control strategies. To address this issue, this work proposes an online state estimator based on a Radial Basis Function (RBF) neural network that operates in closed loop together with a control law derived on a linear algebra-based design strategy. The proposed methodology is applied to a class of nonlinear systems with three types of uncertainties: (i) time-varying parameters, (ii) uncertain nonlinearities, and (iii) unmodeled dynamics. To reduce the effect of uncertainties on the bioreactor, some integrators of the tracking error are introduced, which in turn allow the derivation of the proper control actions. This new control scheme guarantees that all signals are uniformly and ultimately bounded, and the tracking error converges to small values. The effectiveness of the proposed approach is illustrated on the basis of simulated experiments on a fed-batch bioreactor, and its performance is compared with two controllers available in the literature.

Autores
Gandolfo, D.; Salinas, L.; Santos Brandao, A.; Toibero, M.;

Resumen:
A substantial interest in aerial robots has grown in recent years. However, the energetic cost of flying is one of the key challenges nowadays. Rotorcrafts are heavier-than-air flying machines that use lift generated by one or several rotors (vertically oriented propellers) and because of this they spend a large proportion of their available energy to maintain their own weight in the air. In this paper, this concept is used to evaluate the relationship between navigation speed and energy consumption in a miniature quadrotor helicopter which travels over a desired path. A novel path following controller is proposed in which the speed of the rotorcraft is a dynamic profile that varies with the geometric requirements of the desired path. The stability of the control law is proved using the Lyapunov theory. Experimental results using a real quadrotor show the good performance of the proposed controller and the percentages of involved energy are quantified using a model of a lithium polymer battery that was previously identified.

Autores
Leica, P.; Roberti, F.; Monllor, M.; Toibero, M.; Carelli, R.;

Resumen:
This paper presents a control strategy for human– robot interaction with physical contact, recognizing the human intention to control themovement of a non-holonomic mobile robot. The human intention is modeled by mechanical impedance, sensing the human-desired force intensity and the human-desired force direction to guide the robot through unstructured environments. Robot dynamics is included to improve the interaction performance. Stability analysis of the proposed control system is proved by using Lyapunov theory. Real experiments of the human–robot interaction show the performance of the proposed controllers.

Autores
Herrera, D.; Roberti, F.; Toibero, M.; Carelli, R.;

Resumen:
A complete characterization of the behavior in human-robot interactions (HRI) includes both: the behavior dynamics and the control laws that characterizes how the behavior is regulated with the perception data. In this way, this work proposes a leader-follower coordinate control based on an impedance control that allows to establish a dynamic relation between social forces and the motion error. For this, it is presented a scheme to identify the impedance based on fictitious social forces, which are described by distance-based potential fields. As part of the validation procedure, it is presented an experimental comparison to select the better of two different fictitious force structures. The criteria are determined by two qualities: least impedance errors during the validation procedure and least parameter variance during the recursive estimation procedure. Finally, with the best fictitious force and its identified impedance, it is designed an impedance control for a mobile robot Pioneer 3AT, which is programmed to follow a human in a structured scenario. According with the results, and, under the hypothesis that moving like humans will be acceptable by humans, it is believed that the proposed control improves the social acceptance of the robot for this kind of interaction.

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

Resumen:
High-order statistics (HOS) are well suited for describing non-Gaussian random processes. These techniques are increasingly being employed in myoelectric research, on both time and frequency domain techniques. This work presents HOS-based techniques using only HOS time domain features to classify myoelectric signals. The auto-, cross- and full- (joint) third-order cumulants are evaluated as EMG-signal feature vectors to be compared between them. Four surface EMG signals were processed for classify motions from the upper limbs. Synergy among channels is characterized by the features in both auto and cross modes, and their incidences for classifying five or six movements are analyzed. In contrast to the third-order auto-cumulants, it had been verified that the third-order cross-cumulants have the same classification rate by working with five or six movements. A myoelectric control scheme and its experimental application were executed with normal and disabled subjects, reaching a classification rates of 90%, in average. Accuracy in online experiments was similar to the off-line classification rate.

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

Resumen:
Noise annoyance and other effects of noise are reasonably correlated with A-weighted sound levels. Currently, the influence of low-frequency content and of sound emergence level (i.e. the sound level difference between total noise and residual noise) on effects of noise are being assessed in laboratories using stimuli based on recordings. Standards intended for regulations often include penalties depending on these factors. The difference between C- and A-weighted sound levels is frequently used as a descriptor of low frequency content. This work proposes a method to optimize the search and combination of a subset of audio files from a large set of noise sources recordings in order to achieve an environmental noise stimulus with previously specified values of factors (i) sound emergence level, (ii) C- A-weighted levels difference, (iii) A-weighted equivalent continuous sound level and (iv) duration of stimulus. The method is implemented, and one hundred stimuli are generated following a full factorial experimental design varying these four factors. The resulting stimuli show small differences between specified and measured values. The mean difference for factors i-iii is 0.46 dB and the maximum is 2.3 dB.

Autores
Accolti, E.; Alamino Naranjo, E.; Alonso Frank, A.; Kuchen, E.; Arballo, B.;

Resumen:
The Auditorio Juan Victoria is a concert hall inside the cultural center of the same name, opened in 1970 in San Juan province, Argentina. The audience area is rectangular with a seating capacity of 976 people. The stage is fan shaped in which 80 musicians seated with their instruments and a choir of 90 singers standing can be accommodated. The hall is 22 m wide, 40 m long and 10 m high. The hall is equipped with a pipe organ with 44 ranks and 3565 pipes. In this article, the acoustic quality of the hall is assessed by a questionnaire and acoustic parameters are measured using the state of the art methods, including ISO 3382-1 parameters and subjective evaluation. Results are compared with subjective and objective data from other similar halls and recommended values from literature.

Autores
Miyara, F.; Pasch, V.; Accolti, E.;

Resumen:
Halls for music performance frequently require the design of acoustic reflectors to redirect the sound waves toward the audience. In order to get adequate reflecting properties the usual criterion is that the surface density be no less than 20 kg/m2. However, this may prove too heavy in certain cases, so other possible solutions must be studied. In this paper, light-weight reflectors, such as medium density fibreboard or plywood panels clamped at their boundaries, where structural rigidity replaces mass at the low frequency end, have been investigated. A compliance model is compared with the mass model showing that the structure is suitable.

Autores
Santiago, D.; Slawiñski, E.; Mut, V.;

Resumen:
This paper proposes a control scheme for a stable teleoperation of non-holonomic mobile manipulator robots. This configuration presents high-coupled dynamics and motion redundancy. The problem approached in this work is the teleoperation of the end effector velocity of the Mobile Manipulator, while system redundancy is used to achieve secondary control objectives. We considered variable asymmetric time delays as well as non-passive models of operator and environment. From this study, it is possible to infer the control parameters, depending on the time delay, in order to assure stability. Finally,the performance of the delayed teleoperation system is evaluated through simulations of human-in-the-loop internet teleoperation.

Autores
Gandolfo, D.; Salinas, L.; Serrano, E.; Toibero, M.;

Resumen:
Nowadays, the energetic cost of flying in electric-powered UAVs is one of the key challenges. The continuous evolution of electrical energy storage sources is overcome by the great amount of energy required by the propulsion system. Therefore, the on-board energy is a crucial factor that needs to be further analyzed. In this work, different control strategies applied to a generic UAV propulsion system are considered and a lithium polymer battery dynamic model is included as the propulsion system energy source. Several simulations are carried out for each control strategy, and a quantitative evaluation of the influence of each control law over the actual energy consumed by the propulsion system is reported. This energy, which is delivery by the battery, is next compared against a well-known control-effort-based index. The results and analysis suggest that conclusions regarding energy savings based on control effort signals should be drawn carefully, because they do not directly represent the actual consumed energy.

Autores
Slawiñski, E.; Santiago, D.; Chavez, G.; Mut, V.;

Resumen:
Este trabajo propone un esquema de control modificado, basado en una estructura tipo-PD más impedancia, aplicado a la teleoperación bilateral de un robot móvil considerando retardos de tiempo. El esquema es diseñado para obtener una relación de compromiso entre estabilidad y transparencia, analizando ambas característicassimultáneamente. El análisis correspondiente toma en cuenta las dinámicas del maestro y del robot móvil tanto como retardos variables y asimétricos. Finalmente, se muestran los resultados de pruebas de teleoperación bilateral realizados incluyendo el controlador propuesto de manera de verificar el resultado teórico alcanzado.

Autores
Santiago, D.; Slawiñski, E.; Mut, V.;

Resumen:
This paper analyzes the stability of a trilateral teleoperation system of a mobile robot. This type of system is nonlinear, time-varying, and delayed and includes a master-slave kinematic dissimilarity. To close the control loop, three P+D controllers are used under a position master/slave velocity strategy. The stability analysis is based on Lyapunov-Krasovskii theory where a functional is proposed and analyzed to get conditions for the control parameters that assure a stable behavior, keeping the synchronism errors bounded. Finally, the theoretical result is verified in practice by means of a simple test, where two human operators both collaboratively and simultaneously drive a 3D simulator of a mobile robot to achieve an established task on a remote shared environment.

Autores
Slawiñski, E.; Santiago, D.; Mut, V.;

Resumen:
This paper proposes a cascade control scheme for delayed bilateral teleoperation of a quadcopter. The strategy transforms a 6D real quadcopter to an easy-to-teleoperate 3D virtual quadcopter. The scheme is formed by a P+d plus PID controller for each dof. The analysis based on Lyapunov theory gets as result the way to set the control parameters depending on the magnitude of the asymmetric time delays (forward and backward delays). This technic aims to reach stability, simplicity and good performance in practice. Besides, experimental tests about delayed bilateral teleoperation of a quadcopter including the proposed control scheme are shown in order to evaluate the system performance.

Autores
Capraro Fuentes, F.; Rossomando, F.; Soria, C.; Scaglia, G.;

Resumen:
A design of sliding mode controllers (SMC) with adaptive capacity is presented. This control technique is formed by two cascaded SMC controllers, one of them having an adaptive neural compensator (ANC); both are put on a WMR (wheeled mobile robot). The mobile robot is divided into a kinematics and a dynamics structure; the first SMC controller acts only on the kinematic structure and the SMC with neural adaptive compensator on the other one. The dynamic SMC was designed applying an inverse dynamic controller and using the model dynamics of the WMR. The adaptive neural compensation (ANC) was used in order to reduce the control error caused by the dynamics variations but it conveys a residual approximation error, so a sliding part was designed to cancel such error. This technique allows achieving the control objective despite parameter variations and external disturbances that take place in the dynamics; on the other hand, the ANC can adjust its neural parameters to reduce the dynamics variations of the WMR and thus improve the trajectory tracking control. Problems of convergence and stability are treated and design rules based on Lyapunov's theorem are given.

Autores
Silvia E. Rodrigo ;Claudia N. Lescano ; Patiño, D.;

Resumen:
Traditionally, the pneumatic proportional-pressure valve dynamics has been characterised from its output pressure and input reference voltage relationship. However, in our application about the use of a pneumatic artificial muscle as actuator of a gait rehabilitation exoskeleton, where an adequate valve output pressure control is required to simultaneously attain a smooth joint movement and an efficient interaction force with the patient, it is also important to evaluate the effect on valve output pressure of the input airflow rate disturbance caused by downstream load variations during this actuator operation. In this paper we present a new global linear model for such application, considering the concurrent effect on valve output of both voltage and airflow rate inputs. From data acquired through an experimental setup and for reference inputs in the frequency range of human gait, two transfer functions describing the relationships between valve output pressure and their respective inputs were first obtained. Second, the individual models were combined in a global one, according to the superposition principle. Third, the resultant model was analysed in the time and frequency domains and finally, validated (MSE = 0.0499) and discussed, in the search for clues to design a suitable actuation system for this type of robotic device.

Autores
Martins, F.; Sarcinelli-Filho, M.; Carelli, R.;

Resumen:
An important issue in the field of motion control of wheeled mobile robots is that the design of most controllers is based only on the robot’s kinematics. However, when high-speed movements and/or heavy load transportation are required, it becomes essential to consider the robot dynamics as well. The control signals generated by most dynamic controllers reported in the literature are torques or voltages for the robot motors, while commercial robots usually accept velocity commands. In this context, we present a velocity-based dynamic model for differential drive mobile robots that also includes the dynamics of the robot actuators. Such model has linear and angular velocities as inputs and has been included in Peter Corke’s Robotics Toolbox for MATLAB, therefore it can be easily integrated into simulation systems that have been built for the unicycle kinematics. We demonstrate that the proposed dynamic model has useful mathematical properties. We also present an application of such model on the design of an adaptive dynamic controller and the stability analysis of the complete system, while applying the proposed model properties. Finally, we show some simulation and experimental results and discuss the advantages and limitations of the proposed model.

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

Resumen:
This paper presents a low-cost localization system to guide an Unmanned Aerial Vehicle (UAV) in indoor flights, considering an environment with invariant texture and typical indoor illumination. The first contribution of the paper is the proposal of a system to estimate the position and orientation of the UAV, through a multi-sensor fusion scheme, dealing with data provided by a RGB-D sensor, an inertial measurement unit (IMU), an ultrasonic sensor and optical flow-based velocity estimates. A second contribution of the paper is the proposal of a high-level control system to guide the UAV in path-following tasks, involving two controllers: a kinematic one, responsible for generating reference velocities for the vehicle, and a PD one, responsible for tracking such reference velocities, thus characterizing a cascade controller. Experiments with such a localization and control systems, during which abrupt disturbances are applied, were carried out to check the effectiveness of the developed capture and control systems, whose results validate the proposed framework.

Autores
Milton Cesar Paes Santos ; Rosales, C.; Sarcinelli-Filho, M.; Carelli, R.;

Resumen:
A new trajectory tracking controller with collision avoidance is proposed in this paper for unmanned aerial vehicle (UAV) navigation. A positive potential function is designed to take into account the movement of obstacles. Thus, the controller with potential function guarantees that the UAV moves through areas of potentials close to zero to ensure safe navigation in dynamic and unknown environments. Such a controller was designed with hierarchical objectives using a behavioral-based approach. A nullspace-based controller is adopted, whose main objective is to ensure that the collision avoidance is achieved, whereas other objectives are projected onto the null space. Collision avoidance and trajectory tracking controllers generate reference velocities sent to a dynamic compensator to guarantee the tracking of such velocities, thus characterizing a cascade controller. Stability of the entire closed-loop nonlinear system is demonstrated through Lyapunov’s theory. A low-cost indoor framework with just one RGB-D sensor, which is a combination of a RGB (red-green-blue) camera with a depth sensor based on infrared light was used to estimate the positions of the UAV and obstacles. Simulation and experiments are run using a Parrot AR.Drone quadrotor and considering a person as a dynamic obstacle for an AR.Drone quadrotor, and some of their results are reported to validate the proposed controller.

Autores
María N. Pantano ; Serrano, E.;María C. Fernández ; Rossomando, F.; Ortiz, O.; Scaglia, G.;

Resumen:
This paper aims to solve the problem of tracking optimal profiles for a nonlinear multivariable fedbatch bioprocess by a simple but efficient closed-loop control technique based on a linear algebra approach. In the proposed methodology, the control actions are obtained by solving a system of linear equations without the need for state transformations. The optimal profiles to follow are directly those corresponding to output desired variables, therefore, estimation of states for nonmeasurable variables is considered by employing a neural networks method. The efficiency of the proposed controller is tested through several simulations, including process disturbances and operation under parametric uncertainty. The optimal controller parameters are selected through the Montecarlo Randomized Algorithm. In addition, proof of convergence to zero of tracking errors is analyzed and included in this article.

Autores
Rossomando, F.; Soria, C.;

Resumen:
This work presents a discrete-time sliding mode neuro-adaptive control (DTSMNAC) method for robot manipulators. Due to the dynamics variations and uncertainties in the robot model, the trajectory tracking of robot manipulators has been one of the research areas for the last years. The proposed control structure is a practical design that combines a discrete-time neuro-adaptation technique with sliding mode control to compensate the dynamics variations in the robot. Using an online adaptation technique, a DTSMNAC controller is used to approximate the equivalent control in the neighborhood of the sliding surface. A sliding control is included to guarantee that the discrete-time neural sliding mode control can improve a stable closed-loop system for the trajectory tracking control of the robot with dynamics variations. The proposed technique simultaneously ensures the stability of the adaptation of the neural networks and can be obtained a suitable equivalent control when the parameters of the robot dynamics are unknown in advance. This neural adaptive system is applied to a SCARA robot manipulator and shows to be able to ensure that the output tracking error will converge to zero. Finally, experiments on a SCARA robot have been developed to show the performance of the proposed technique, including the comparison with a PID controller.

Autores
Diego Daniel Santiago ;Emanuel Slawiñski ;Vicente Mut ;

Resumen:
This paper proposes a control scheme for a stable teleoperation of non-holonomic mobile manipulator robots. This configuration presents high-coupled dynamics and motion redundancy. The problem approached in this work is the teleoperation of the end effector velocity of the Mobile Manipulator, while system redundancy is used to achieve secondary control objectives. We considered variable asymmetric time delays as well as non-passive models of operator and environment. From this study, it is possible to infer the control parameters, depending on the time delay, in order to assure stability. Finally,the performance of the delayed teleoperation system is evaluated through simulations of human-in-the-loop internet teleoperation.

Autores
Paes Santos, M.; Rosales, C.; Sarapura, J.; Sarcinelli-Filho, M.; Carelli, R.;

Resumen:
This work proposes an adaptive dynamic controller for an unmanned aerial vehicle (UAV) to track a desired trajectory. Initially, reference velocities are generated by a controller that is based only on the kinematic model of the UAV. Subsequently, new control actions are calculated to compensate for the internal dynamics of the robot. Then the model parameters that characterize the robot dynamics are updated during navigation, chareacterizing an adaptive controller. In this way, the performance of the flight application with the quadrotor is improved, since the control errors are minimized. The stability of the proposed control system is proven, based on the Lyapunov theory. Finally, simulated results are presented, demonstrating the good performance of the controller even without any previous knowledge of the values of the parameters of the UAV dynamics.

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

Resumen:
This work presents an adaptive trajectory tracking controller for an unmanned aerial vehicle (UAV) which combines a feedback linearization controller based on a nominal model of a quadrotor and a Neuro Adaptive Compensation (NAC). The NAC is introduced in order to minimize the control errors caused by uncertainties in the nominal parameters. The uncertain parameters of the nominal model are balanced by a Neuro Adaptive Compensator. The proposed adaptive control scheme is robust and efficient to achieve a good trajectory following performance for outdoor and indoor applications. The analysis of the neural approximation error on the control errors is included. Finally, the effectiveness of the control system is proved through numerical simulation.

Autores
Mario Jimenez ; Monllor, M.; Frizera Neto, A.; Freire Bastos, T.; Roberti, F.; Carelli, R.;

Resumen:
El porcentaje de personas con discapacidad en la movilidad se hace cada vez mayor debido principalmente al aumento en la población de personas mayores de 60 años, y a personas que sufren de alguna patología clínica o se han sometido a alguna cirugía. Teniendo en cuenta que caminar es una de las actividades principales del diario vivir y que trae consigo muchas ventajas relacionadas con la salud de la persona, el desarrollo de herramientas de asistencia robóticas toma interés al momento de asistir la locomoción. En este caso, se propone el uso de un caminador robótico inteligente (Smart Walker) para guiar el desplazamiento de una persona en un pasillo. El controlador se evaluó usando tres posiciones iniciales y el error medio de posición fue de 0.38 ±0.08m, Sin embargo, se debe decir que una vez el Smart Walker se posiciona sobre el camino deseado, no consigue salir de éste.

Autores
Montesdeoca, J.; Herrera, D.; Toibero, M.; Carelli, R.;

Resumen:
—This paper presents the simulation results of the controllers design for differential-drive mobile robot (DDMR) using a novel modeling method, which is based on the inclusion of the sideway velocity into the kinematic modeling, in order to obtain a holonomic-like model. Next, non-holonomic constraint is introduced assuming that the sideway slipping is measurable. The controller design considers a variable position for the point of interest and takes into account also the robot constrained inputs. The obtained inverse kinematics controller is differentiable, time invariant and naturally incorporates the sideway slipping which is considered measurable. Moreover, the proposed controller can be used for both: trajectory tracking and path following by setting appropriate desired values at the planning stage. The Lyapunov theory is used to prove the stability of the control system. Simulator includes a robot dynamics module that supports physics engines. Obtained simulations results show a high performance for both tasks.

Autores
Leica, P.;Marco Herrera ; Rosales, C.; Roberti, F.; Toibero, M.; Carelli, R.;

Resumen:
This paper presents a new dynamic obstacle avoidance strategy based on time-variation of a potential field, with multiple control objectives. The strategy uses the null space of a Jacobian matrix to achieve the different control objectives in a non-conflicting way while using either a flexible or a rigid formation to avoid static and mobile obstacles. By modifying the priorities of control objectives without changing the controller structure. Overall control system stability is analyzed and proven through Lyapunov theory. Experimental results for a three-robot formation show the performance of the proposed controllers.

Autores
Montesdeoca, J.; Toibero, M.; Carelli, R.;

Resumen:
This paper presents the design of a kinematic controller for autonomous person-following based on social navigation for human-robot interaction purposes. This controller modifies the length of personal space using the human velocity in order to allow the human user senses a natural movement by mobile robot. In this way, the social behavior is incorporated into the controller, allowing a social navigation of differential drive mobile robot (DDMR) in shared environments in both cases, sensorized environments or humans users that wear an inertial movement unit (IMU) in order to track the position. The stability proof of closed-loop control system is based on Lyapunov theory. Simulations show a good performance when human user moves forwards backwards, and also through an arbitrary path.

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

Resumen:
The simplest room acoustics formulas are valid in a diffuse sound field. How is a diffuse sound field defined? Which is the scope of these formulas? These questions are analyzed through more general theories, in turn explained with figures instead of formulas with the intention to approachquickly to the concepts. The scope of the diffuse field model is analyzed and simple tools are presented to address the cases in which it would not be adequate assuming diffuse field. The wave theory model and the ray model are presented in a simple format with visual support and a succinct reference to the underlying mathematical models. A discussion about the current criteria to define a diffuse sound field in the frequency domain as well as in the time domain is proposed.

Autores
Orellana, A.; Lage, A.; Correa, J.; Durán , T.;

Resumen:
With the aim of improve minig safety, this work presents a new development intended to detect a long eye closure of the drivers of huge mining trucks. Information is being captured with an artificial vision system and the resulting images are being processed using the “dlib” library. The improvements achieved are going to be incorporated in an integrating system intended to globally improve the mining operators of huge machines safety. The system object of this work is being developed to be incorporated into the driver's cabin. The camera's processed information with the speed information are going to trigger alert signals for the driver of the vehicle, as well as for the mining trucks control center. The hardware of the present development is composed of a near infrared camera and illuminator intended to detect the eyes and eyelid's state as “open” or “closed”. The complete system, beyond the present work, will include another camera that will sense the steering-wheel movements, driver's head position and a GPS that will be sensing the vehicle speed and position.

Autores
Montesdeoca, J.; Toibero, M.; Carelli, R.;

Resumen:
This paper presents a brief state-of-art about human-robot interaction, it is oriented to social consideration into this topic research. Here is describing the different branches evolution of human-robot interaction such as physical, spatial and social interaction. Also it is included the main advances reported around every research branch aforementioned, some challenges to solve in a near future are described too.

Autores
Monllor, M.; Roberti, F.;Mario Jimenez ; Frizera Neto, A.; Carelli, R.;

Resumen:
In the present work, a path following control for assistance robots is designed. The driver is designed to help blind people reach a destination through a path. This work is on the premise that person must choose the moment when the robot has to move due to it is using as support. Plus a linear velocity is generated an angular velocity which guides the person along the path, whenever the movement is desired by the user. A simulation is performed to verify that the operation of the controller is correct, and finally, experiments are performed on an experimental platform.

Autores
Herrera, D.; Monllor, M.; Carelli, R.;Jan Carstensen ; Wagner, B.;

Resumen:
Balancing a rotary inverted pendulum (RIP) is commonly used for testing control algorithms, and the teaching of control chairs. Even when the researchers have proposed multiple model-based control designs over simulation environments, or based on previously identified RIP systems, the practical setup of an experimental prototype has been commonly neglected because the difficulty that represents to identify a multi-variable, unstable, and highly non-linear system. This fact motivates the development of an experimental methodology to set-up a RIP system. For this, a mechanical model based on EulerLagrange is derived, where the inclusion of its actuator system is considered, which consists of a DC-motor model and a PD-lowlevel controller. Later, the proposed model is linearized over the non-stable equilibrium and the design of a balance control based on LQR is proposed. Finally, an experimental methodology to get the balance of an experimental RIP system based on input/output data is proposed, and its good performance is demonstrated with a RIP prototype.

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

Resumen:
This work presents a non parametric probabilistic mapping based on kernel estimators which does not use grids.The proposed methodology characterizes the map with a cloud of points obtained from several observations of the environment. In order to maintain a bounded number of observations in memory, a recursive subsampling algorithm is proposed. The procedure is included in an SLAM, in order to localize the robot as well. An application example is the presented, where the proposed methodology is applied in an agricultural environment. Simulation and experimentation results are presented to validate the proposal.

Autores
Montesdeoca, J.;Milton C. P. Santos ; Monllor, M.; Herrera, D.;

Resumen:
This paper describes a time-invariant controller for trajectory tracking applied to the differential-drive mobile robot (DDMR), where the interest point position is located in an arbitrary position, the extended kinematic model of DDMR is used to propose a inverse kinematic controller; where, the extended kinematic model proposes a holonomic-like model for non-holonomic system, allowing this way, the use of inverse kinematic as control strategy. The system stability is proved by according to the Lyapunov theory, concluding that the system is asymptotically stable. Simulations show a good controller performance for different trajectories proposed.

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

Resumen:
Autonomous flight with UAVs is a desirable feature in applications such as the surveillance and inspection of large areas including crop areas. In this context, the development of a passivity based visual servoing controller with dynamics compensation for the tracking of roads is presented in this paper. The proposed system allows the autonomous navigation of a UAV on straight lines such as those found in areas of structured crops. The stability of the controller is shown in the context of the input-output theory and based on the passivity properties of the system. The performance of the resulting control system is shown by simulation.

Autores
MOYA GONZÁLEZ, V.; Slawiñski, E.; Mut, V.;Eduardo H.M.Couto ;

Resumen:
This paper proposes a brain signals based method to evaluate a human operator workload while teleoperating a mobile robot in presence of time delay. The procedure based on denoising and decomposition wavelet transform can be applied to raw EEG signals, analyzing the energy in the delta band to detect four states of cognitive workload. The index obtained is validated using the NASA-TLX question nary and quantitative metrics like time-to-complete the task and error of path tracking.

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

Resumen:
The development of human-friendly applications are focused on abstracting social behaviors as part of the robotic design. The most important is without doubt the social zone, which acts like a repulsive potential field to protect the personal space of humans and in consequence to avoid its intrusion. In robotics, many approaches have been proposed to define and to avoid these fields, which contributes to improve the human comfort during interactions. This paper proposes a novel nullspace-based (NSB) algorithm for a non-holonomic mobile robot platform, which is programmed to escort a human in a behaviourbased paradigm. The emphasis is posed in the evasion of other humans in the environment by considering them as elliptical potential fields with non-holonomic motion. Finally, experimental results are presented to show the performance of the proposed control algorithm with static and dynamic human obstacles.

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

Resumen:
En este trabajo se propone una arquitectura de control basada en la fusión de las acciones de control generadas por tres controladores sencillos (controladores PVTOL, del inglés Planar Vertical Take-Off and Landing) para guiar vehículos aéreos autónomos en posicionamiento y seguimiento de caminos 3D. Considerando la navegación como una tarea compuesta por el control de la orientación del vehículo en relación al blanco (asociada a un controlador Z-PVTOL), por el control de su movimiento hacia adelante (asociado a un controlador XZ-PVTOL), y por la corrección de cualquier desplazamien- to lateral (asociada a un controlador YZ-PVTOL, similar al controlador XZ-PVTOL), nuestro primer abordaje consistió en ejecutar dichas maniobras parciales una por vez, utilizando los controladores PVTOL, conmutando de uno al otro mediante la acción de un supervisor. En este trabajo el abordaje se cambió, pasando a considerarse que los controladores PVTOL actúan simultáneamente y generando la acción de control final mediante la fusión de las acciones de control generadas por ellos, acoplando así suavemente tres controladores muy sencillos. Se presentan resultados experimentales para validar el abordaje propuesta, y su desempeño en vuelo es comparado con el desempeño correspondiente a la estrategia de conmutación.

Autores
Montesdeoca, J.; Salinas, L.; Toibero, M.; Carelli, R.;

Resumen:
En este documento se presenta los resultados de simulación del diseño de un controlador cinemático para seguimiento de trayectoria aplicado a un robot móvil tipo auto. Dentro del diseño de la ley de control se considera las limitaciones de giro en el volante y la limitada velocidad del robot. Además de ello se considera el punto de interés en una posición arbitraria dentro o fuera del cuerpo del robot. La trayectoria se obtiene de un proceso de planificación en donde se presta atención a la limitación del giro del volante. Las simulaciones muestran un gran desempeño del controlador.

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

Resumen:
Se propone un nuevo controlador cinemático de formación basado en la teoría del espacio nulo para transportar una carga por medio de cables con dos UAVs considerando evasión de obstáculos, perturbaciones del viento y distribución equitativa del peso de la carga. Para probar la propuesta en un escenario realista se considera un modelo dinámico no lineal preciso con 6 grados de libertad de un helicóptero y modelos para cables flexibles y para la carga. La estabilidad del sistema se demuestra usando la teoría de Lyapunov y se valida su desempeño con una simulación completa del sistema.

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

Resumen:
Este artículo propone un controlador neuro- adaptable indirecto con control supervisor para UAVs. Esta técnica requiere un observador de estados del error de control, debido a que el vehículo está afectado con ruido de medición y perturbaciones externas. En este estudio el error de control es estimado por el observador de estados a partir del cual el sistema neuronal adaptable genera una acción de control y el término supervisor estabiliza el sistema. Los parámetros del controlador neuro-adaptable indirecto pueden ser sintonizados en línea mediante las leyes de ajuste que dependen el error obtenido por el observador, estas leyes de ajuste fueron obtenidas a través el criterio de estabilidad de Lyapunov. Los resultados experimentales demuestran un buen desempeño de la técnica propuesta para el seguimiento completo de trayectorias de referencia en ambientes afectados por ruidos de medición.

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

Resumen:
En la vigilancia e inspección de grandes áreas tales como zonas de cultivos, y en aplicaciones donde el uso de sensores como GPS no resulta adecuado, el vuelo autónomo es una característica deseable en los vehículos aéreos no tripulados (UAV). Bajo este tema, se presenta una comparación de desempeño de controladores servovisuales con compensación de la dinámica para el seguimiento de caminos diseñados en trabajos anteriores. Los sistemas propuestos permiten la navegación autónoma de un UAV sobre líneas vegetales como las que se encuentran en zonas de cultivos estructuradas. El desempeño de los sistemas se compara mediante resultados de simulación.

Autores
Slawiñski, E.; Mut, V.;

Resumen:
This paper analyzes the stability of a trilateral teleoperation system of a mobile robot. The dynamics of two manipulator-like masters and mobile robot as well as time- varying and asymmetric delays are taken into account. A set of P+d controllers is included into the delayed teleoperation system. From the analysis performed, a procedure to set the control parameters is proposed in order to assure the stability of the whole system. Finally, the theoretical result is verified in practice by means of a simple test about delayed trilateral teleoperation system, where two human operators both collaboratively and simultaneously drive a 3D simulator of a mobile robot to achieve an established task on a remote environment.

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

Resumen:
En el presente trabajo se plantea un controlador de impedancia para robots de asistencia sensible a los obstáculos. El control guía al usuario de su posición a un punto deseado esquivando los eventuales obstáculos que se presenten en el camino, condicionando al usuario a desplazarse dentro de una zona segura, actuando sobre las consignas de velocidad angular del robot; de forma tal que no exista la posibilidad de colisiones. El usuario tiene control sobre el momento de desplazamiento. Se realizan simulaciones con varios obstáculos fijos, utilizando señales de fuerzas que imitan de forma simplificada la marcha humana.

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

Resumen:
En el presente trabajo se desarrolla un regulador sub-óptimo de tiempo finito basado en LQR para lograr que el robot navegue desde una posición y orientación inicial arbitraria hasta el origen del sistema de referencia fijo en el espacio de trabajo. El algoritmo de control se diseña considerando el modelo cinemático de un robot móvil tipo uniciclo. Se plantean dos modos de funcionamiento del control, y se verifica el funcionamiento del controlador mediante simulación y experimentación.