Handling high parameter dimensionality in reinforcement learning with dynamic motor primitives

Dynamic Motor Primitives (DMP) are nowadays widely used as movement parametrization for learning trajectories, because of their linearity in the parameters, rescalation robustness and continuity. However, when learning a movement with DMP, where a set of gaussians distributed along the trajectory is used to approximate an acceleration excitation function, a very large number of gaussian approximations need to be performed. Adding them up for all joints yields too many parameters to be explored, thus requiring a prohibitive number of experiments/simulations to converge to a solution with an optimal (locally or globally) reward. We propose here two strategies to reduce this dimensionality: the first is to explore only the most significant directions in the parameter space, and the second is to add a reduced second set of gaussians that should only optimize the trajectory after fixing the gaussians that approximate the demonstrated movement.Peer ReviewedPostprint (author’s final draft

Robot motion adaptation through user intervention and reinforcement learning

© . This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Assistant robots are designed to perform specific tasks for the user, but their performance is rarely optimal, hence they are required to adapt to user preferences or new task requirements. In the previous work, the potential of an interactive learning framework based on user intervention and reinforcement learning (RL) was assessed. The framework allowed the user to correct an unfitted segment of the robot trajectory by using hand movements to guide the robot along a corrective path. So far, only the usability of the framework was evaluated through experiments with users. In the current work, the framework is described in detail and its ability to learn from a set of sample trajectories using an RL algorithm is analyzed. To evaluate the learning performance, three versions of the framework are proposed that differ in the method used to obtain the sample trajectories, which are: human-guided learning, autonomous learning, and combined human-guided with autonomous learning. The results show that the combination of the human-guided and autonomous learning achieved the best performance, and although it needed a higher number of sample trajectories than the human-guided learning, it also required less user involvement. Autonomous learning alone obtained the lowest reward value and needed the highest number of sample trajectories.Peer ReviewedPostprint (author's final draft

Reward-weighted GMM and its application to action-selection in robotized shoe dressing

The final publication is available at link.springer.comIn the context of assistive robotics, robots need to make multiple decisions. We explore the problem where a robot has multiple choices to perform a task and must select the action that maximizes success probability among a repertoire of pre-trained actions. We investigate the case in which sensory data is only available before making the decision, but not while the action is being performed. In this paper we propose to use a Gaussian Mixture Model (GMM) as decision-making system. Our adaptation permits the initialization of the model using only one sample per component. We also propose an algorithm to use the result of each execution to update the model, thus adapting the robot behavior to the user and evaluating the effectiveness of each pre-trained action. The proposed algorithm is applied to a robotic shoe-dressing task. Simulated and real experiments show the validity of our approach.Peer ReviewedPostprint (author's final draft

Realtime tracking and grasping of a moving object from range video

In this paper we present an automated system that is able to track and grasp a moving object within the workspace of a manipulator using range images acquired with a Microsoft Kinect sensor. Realtime tracking is achieved by a geometric particle filter on the affine group. Based on the tracked output, the pose of a 7-DoF WAM robotic arm is continuously updated using dynamic motor primitives until a distance measure between the tracked object and the gripper mounted on the arm is below a threshold. Then, it closes its three fingers and grasps the object. The tracker works in real-time and is robust to noise and partial occlusions. Using only the depth data makes our tracker independent of texture which is one of the key design goals in our approach. An experimental evaluation is provided along with a comparison of the proposed tracker with state-of-the-art approaches, including the OpenNI-tracker. The developed system is integrated with ROS and made available as part of IRI's ROS stack.Peer ReviewedPostprint (author’s final draft

External force estimation for textile grasp detection

Our current work on external force estimation without end-effector force sensor is resented.To verify if a grasp of a textile has been successful, the external wrench applied on the robot is computed online, with a state observer based on a LWPR [3] model of a task.Peer ReviewedPostprint (author’s final draft

DVINO: A RISC-V vector processor implemented in 65nm technology

This paper describes the design, verification, implementation and fabrication of the Drac Vector IN-Order (DVINO) processor, a RISC-V vector processor capable of booting Linux jointly developed by BSC, CIC-IPN, IMB-CNM (CSIC), and UPC. The DVINO processor includes an internally developed two-lane vector processor unit as well as a Phase Locked Loop (PLL) and an Analog-to-Digital Converter (ADC). The paper summarizes the design from architectural as well as logic synthesis and physical design in CMOS 65nm technology.The DRAC project is co-financed by the European Union Regional Development Fund within the framework of the ERDF Operational Program of Catalonia 2014-2020 with a grant of 50% of total eligible cost. The authors are part of RedRISCV which promotes activities around open hardware. The Lagarto Project is supported by the Research and Graduate Secretary (SIP) of the Instituto Politecnico Nacional (IPN) from Mexico, and by the CONACyT scholarship for Center for Research in Computing (CIC-IPN).Peer ReviewedArticle signat per 43 autors/es: Guillem Cabo∗, Gerard Candón∗, Xavier Carril∗, Max Doblas∗, Marc Domínguez∗, Alberto González∗, Cesar Hernández†, Víctor Jiménez∗, Vatistas Kostalampros∗, Rubén Langarita∗, Neiel Leyva†, Guillem López-Paradís∗, Jonnatan Mendoza∗, Francesco Minervini∗, Julian Pavón∗, Cristobal Ramírez∗, Narcís Rodas∗, Enrico Reggiani∗, Mario Rodríguez∗, Carlos Rojas∗, Abraham Ruiz∗, Víctor Soria∗, Alejandro Suanes‡, Iván Vargas∗, Roger Figueras∗, Pau Fontova∗, Joan Marimon∗, Víctor Montabes∗, Adrián Cristal∗, Carles Hernández∗, Ricardo Martínez‡, Miquel Moretó∗§, Francesc Moll∗§, Oscar Palomar∗§, Marco A. Ramírez†, Antonio Rubio§, Jordi Sacristán‡, Francesc Serra-Graells‡, Nehir Sonmez∗, Lluís Terés‡, Osman Unsal∗, Mateo Valero∗§, Luís Villa† // ∗Barcelona Supercomputing Center (BSC), Barcelona, Spain. Email: [email protected]; †Centro de Investigación en Computación, Instituto Politécnico Nacional (CIC-IPN), Mexico City, Mexico; ‡ Institut de Microelectronica de Barcelona, IMB-CNM (CSIC), Spain. Email: [email protected]; §Universitat Politecnica de Catalunya (UPC), Barcelona, Spain. Email: [email protected] (author's final draft

TFG 2012/2013

Amb aquesta publicació, EINA, Centre universitari de Disseny i Art adscrit a la Universitat Autònoma de Barcelona, dóna a conèixer el recull dels Treballs de Fi de Grau presentats durant el curs 2012-2013. Voldríem que un recull com aquest donés una idea més precisa de la tasca que es realitza a EINA per tal de formar nous dissenyadors amb capacitat de respondre professionalment i intel·lectualment a les necessitats i exigències de la nostra societat. El treball formatiu s’orienta a oferir resultats que responguin tant a paràmetres de rigor acadèmic i capacitat d’anàlisi del context com a l’experimentació i la creació de nous llenguatges, tot fomentant el potencial innovador del disseny.Con esta publicación, EINA, Centro universitario de diseño y arte adscrito a la Universidad Autónoma de Barcelona, da a conocer la recopilación de los Trabajos de Fin de Grado presentados durante el curso 2012-2013. Querríamos que una recopilación como ésta diera una idea más precisa del trabajo que se realiza en EINA para formar nuevos diseñadores con capacidad de responder profesional e intelectualmente a las necesidades y exigencias de nuestra sociedad. El trabajo formativo se orienta a ofrecer resultados que respondan tanto a parámetros de rigor académico y capacidad de análisis, como a la experimentación y la creación de nuevos lenguajes, al tiempo que se fomenta el potencial innovador del diseño.With this publication, EINA, University School of Design and Art, ascribed to the Autonomous University of Barcelona, brings to the public eye the Final Degree Projects presented during the 2012-2013 academic year. Our hope is that this volume might offer a more precise idea of the task performed by EINA in training new designers, able to speak both professionally and intellectually to the needs and demands of our society. The educational task is oriented towards results that might respond to the parameters of academic rigour and the capacity for contextual analysis, as well as to considerations of experimentation and the creation of new languages, all the while reinforcing design’s innovative potential

Dietary α‐Linolenic Acid, Marine ω‐3 Fatty Acids, and Mortality in a Population With High Fish Consumption: Findings From the PREvención con DIeta MEDiterránea (PREDIMED) Study

Background: Epidemiological evidence suggests a cardioprotective role of α‐linolenic acid (ALA), a plant‐derived ω‐3 fatty acid. It is unclear whether ALA is beneficial in a background of high marine ω‐3 fatty acids (long‐chain n‐3 polyunsaturated fatty acids) intake. In persons at high cardiovascular risk from Spain, a country in which fish consumption is customarily high, we investigated whether meeting the International Society for the Study of Fatty Acids and Lipids recommendation for dietary ALA (0.7% of total energy) at baseline was related to all‐cause and cardiovascular disease mortality. We also examined the effect of meeting the society's recommendation for long‐chain n‐3 polyunsaturated fatty acids (≥500 mg/day). Methods and Results: We longitudinally evaluated 7202 participants in the PREvención con DIeta MEDiterránea (PREDIMED) trial. Multivariable‐adjusted Cox regression models were fitted to estimate hazard ratios. ALA intake correlated to walnut consumption (r=0.94). During a 5.9‐y follow‐up, 431 deaths occurred (104 cardiovascular disease, 55 coronary heart disease, 32 sudden cardiac death, 25 stroke). The hazard ratios for meeting ALA recommendation (n=1615, 22.4%) were 0.72 (95% CI 0.56–0.92) for all‐cause mortality and 0.95 (95% CI 0.58–1.57) for fatal cardiovascular disease. The hazard ratios for meeting the recommendation for long‐chain n‐3 polyunsaturated fatty acids (n=5452, 75.7%) were 0.84 (95% CI 0.67–1.05) for all‐cause mortality, 0.61 (95% CI 0.39–0.96) for fatal cardiovascular disease, 0.54 (95% CI 0.29–0.99) for fatal coronary heart disease, and 0.49 (95% CI 0.22–1.01) for sudden cardiac death. The highest reduction in all‐cause mortality occurred in participants meeting both recommendations (hazard ratio 0.63 [95% CI 0.45–0.87]). Conclusions: In participants without prior cardiovascular disease and high fish consumption, dietary ALA, supplied mainly by walnuts and olive oil, relates inversely to all‐cause mortality, whereas protection from cardiac mortality is limited to fish‐derived long‐chain n‐3 polyunsaturated fatty acids. Clinical Trial Registration URL: http://www.Controlled-trials.com/. Unique identifier: ISRCTN35739639

Enginyeria en la conservació marina: eines i tecnologies emprades al CRAM

En aquest Research Café es presenten projectes on la tecnologia es posa al servei dels mars i els oceans, i que estan lligats amb els objectius ODS Vida Submarina i Acció pel clima.Objectius de Desenvolupament Sostenible::13 - Acció per al ClimaObjectius de Desenvolupament Sostenible::14 - Vida Submarin