Docker: Una herramienta para crear imágenes y lanzar múltiples contenedores con ROS OS

Docker is a tool that allows to create containers with everything needed to run an application. This feature makes it key to the process of transferring software products in different environments, allowing code to be ported faster, with better use of resources, and more reliably. ROS 2 (Robot Operating System 2) is an open source SDK for robotics applications that provides hardware abstraction for control, which can benefit from the use of containers. This article presents an introduction to Docker, creating images, launching multiple containers, and most importantly, how it can be used in conjunction with ROS OS for robotics applications.  Docker es una herramienta que permite crear contenedores con todo lo necesario para ejecutar una aplicación. Esta característica la convierte en clave para los procesos de transferencia de productos software en diferentes entornos, al permitir transferir código con mayor rapidez, mejor uso de recursos, y de forma más confiable. ROS 2 (Robot Operating System 2) es un SDK de código libre para aplicaciones en robótica que proporciona abstracción del hardware para el control, que puede verse beneficiado por el uso de contenedores. En este artículo se presenta una introducción a Docker, la creación de imágenes, el lanzamiento de múltiples contenedores, y sobre todo, cómo se puede utilizar en conjunto con ROS OS para aplicaciones de robótica. &nbsp

Revisión de las estrategias de organización en bandadas para enjambres de robots

Robotics promises great benefits for human beings, both at the industrial level and concerning personal services. This has led to the continuous development and research in different problems, including control, manipulation, human-machine interaction, and of course, autonomous navigation. Robot swarm systems promise an alternative solution to the classic high-performance platforms, particularly in applications that require task distribution. Among these systems, flocking navigation schemes are currently attracting high attention. To establish a frame of reference, a general review of the literature to date related to flocking behavior, in particular, optimized schemes with some guarantee of safety, is presented. In most of the cases presented, the characteristics of these systems, such as minimal computational and communication requirements, and event-driven planning, are maintained.La robótica promete grandes beneficios, tanto a nivel industrial como con respecto a servicios personales. Esto ha incidido en el continuo desarrollo e investigación en diferentes problemas, entre ellos el control, la manipulación, la interacción hombre-máquina, y por supuesto, la navegación autónoma. Los sistemas de enjambres de robots prometen una alternativa de solución frente a las clásicas plataformas de alto de desempeño, particularmente en aplicaciones que requieren distribución de tareas. Entre estos sistemas, llama la atención los esquemas de navegación en bandada, los cuales tiene actualmente una alta atención. Para establecer un marco de referencia, se presenta una revisión general de la literatura a la fecha relacionada con comportamientos en bandada, en particular esquemas optimizados y con alguna garantía de seguridad. En la mayoría de los casos presentados se mantienen las características de estos sistemas, como son requisitos mínimos de computación y comunicación, y la planificación basada en eventos

Manejo del robot TurtleBot3 para aplicaciones de navegación mediante ROS

Logo is a programming language that was born in 1967 as a tool for learning programming. Its concept was simple, assign commands to a virtual turtle to trigger its movement. TurtleBot is a robotics research platform with development based on this concept. However, this platform is both hardware and software oriented and is widely accepted internationally, particularly in SLAM (Simultaneous Localization And Mapping), navigation, and manipulation applications. In fact, it is the standard ROS (Robot Operating System) platform. This paper aims to show the handling and programming of this robot for navigation applications using ROS and Python.Logo es un lenguaje de programación que nació en 1967 como herramienta para de aprendizaje en programación. Su concepto era simple, asignar órdenes a una tortuga virtual a fin de provocar su movimiento. TurtleBot es una plataforma de investigación robótica con desarrollo basado en este concepto. Sin embargo, esta plataforma está orientada tanto al hardware como al software, y posee gran aceptación a nivel internacional, particularmente en aplicaciones de SLAM (Simultaneous Localization And Mapping), navegación y manipulación. De hecho, es la plataforma estándar de ROS (Robot Operating System). Este documento pretende mostrar el manejo y programación de este robot para aplicaciones de navegación con el uso de ROS y Python

Design of a controller for wheeled mobile robots based on automatic movement sequencing

There are many kinds of robots and among them the wheeled mobile robots (WMR) stand out, because they are relatively cheap and easy to build. These features make WMRs the test prototypes for control strategies or motion generation. In general, the controllers developed are based on sensory schemes that give an WMR the ability to travel through flat or obstructed environments. However, these strategies are highly reactive, i.e. they are based on the control-action scheme and are not adaptive; or, they are motion schemes built from simulations that assume the environmental conditions to determine the robot's path. In both cases, WMRs do not adapt perfectly to the change of environment, since the controller does not find appropriate movements for the  robot to move from one point to another. Therefore, this article proposesapartial solution to this problem, with a controller that generates sets of adaptive movements for an WMR to travel around its environment from the sensory perception information

Low cost, high performance fuel cell energy conditioning system controlled by neural network

Fuel cells are an important option for the generation of renewable, efficient and environmentally friendly electricity. Although there are commercial applications in the industrial, residential and automotive sectors, it is not yet a mature technology and requires much research, particularly to reduce its costs to a level competitive with other technologies. This research is currently focused not only on the structure of the cell but also on the additional elements and sub systems required for its implementation as an energy solution. In this article, we propose an electrical energy conditioning scheme for the Formic acid fuel cell (direct formic acid fuel cellor DFAFC). This fuel cell was selected for its high performance, and low cost in low and medium power applications. The proposed system consists of a direct current-direct current (DC-DC) regulator supported by a power converter controlled by a Cortex-M3 ARM processor. This CPU is used to propagate a static neural network trained with the non-linear dynamics of the power converter. The power circuit is modeled and simulated to produce  the training parameters. The neural network is trained externally and runs off-line on the processor. The results show not only the regulation capacity of the control scheme but also its response speed to sudden changes in the load

Electric charge in the field of a magnetic event in three-dimensional spacetime

We analyze the motion of an electric charge in the field of a magnetically charged event in three-dimensional spacetime. We start by exhibiting a first integral of the equations of motion in terms of the three conserved components of the spacetime angular momentum, and then proceed numerically. After crossing the light cone of the event, an electric charge initially at rest starts rotating and slowing down. There are two lengths appearing in the problem: (i) the characteristic length $\frac{q g}{2 \pi m}$, where $q$ and $m$ are the electric charge and mass of the particle, and $g$ is the magnetic charge of the event; and (ii) the spacetime impact parameter $r_0$. For $r_0 \gg \frac{q g}{2 \pi m}$, after a time of order $r_0$, the particle makes sharply a quarter of a turn and comes to rest at the same spatial position at which the event happened in the past. This jump is the main signature of the presence of the magnetic event as felt by an electric charge. A derivation of the expression for the angular momentum that uses Noether's theorem in the magnetic representation is given in the Appendix.Comment: Version to appear in Phys. Rev.

Linear LL-positive sets and their polar subspaces

In this paper, we define a Banach SNL space to be a Banach space with a certain kind of linear map from it into its dual, and we develop the theory of linear $L$-positive subsets of Banach SNL spaces with Banach SNL dual spaces. We use this theory to give simplified proofs of some recent results of Bauschke, Borwein, Wang and Yao, and also of the classical Brezis-Browder theorem.Comment: 11 pages. Notational changes since version