Safe Distributed Coordination of Heterogeneous Robots through Dynamic Simple Temporal Networks

Research on autonomous intelligent systems has focused on how robots can robustly carry out missions in uncertain and harsh environments with very little or no human intervention. Robotic execution languages such as RAPs, ESL, and TDL improve robustness by managing functionally redundant procedures for achieving goals. The model-based programming approach extends this by guaranteeing correctness of execution through pre-planning of non-deterministic timed threads of activities. Executing model-based programs effectively on distributed autonomous platforms requires distributing this pre-planning process. This thesis presents a distributed planner for modelbased programs whose planning and execution is distributed among agents with widely varying levels of processor power and memory resources. We make two key contributions. First, we reformulate a model-based program, which describes cooperative activities, into a hierarchical dynamic simple temporal network. This enables efficient distributed coordination of robots and supports deployment on heterogeneous robots. Second, we introduce a distributed temporal planner, called DTP, which solves hierarchical dynamic simple temporal networks with the assistance of the distributed Bellman-Ford shortest path algorithm. The implementation of DTP has been demonstrated successfully on a wide range of randomly generated examples and on a pursuer-evader challenge problem in simulation.

Generative Temporal Planning with Complex Processes

Autonomous vehicles are increasingly being used in mission-critical applications, and robust methods are needed for controlling these inherently unreliable and complex systems. This thesis advocates the use of model-based programming, which allows mission designers to program autonomous missions at the level of a coach or wing commander. To support such a system, this thesis presents the Spock generative planner. To generate plans, Spock must be able to piece together vehicle commands and team tactics that have a complex behavior represented by concurrent processes. This is in contrast to traditional planners, whose operators represent simple atomic or durative actions. Spock represents operators using the RMPL language, which describes behaviors using parallel and sequential compositions of state and activity episodes. RMPL is useful for controlling mobile autonomous missions because it allows mission designers to quickly encode expressive activity models using object-oriented design methods and an intuitive set of activity combinators. Spock also is significant in that it uniformly represents operators and plan-space processes in terms of Temporal Plan Networks, which support temporal flexibility for robust plan execution. Finally, Spock is implemented as a forward progression optimal planner that walks monotonically forward through plan processes, closing any open conditions and resolving any conflicts. This thesis describes the Spock algorithm in detail, along with example problems and test results.

Public and student awareness science: recreational science as a catalyst

When discussing the traditional and new missions of higher education (1996 Report to UNESCO of the International Commission on Education for the 21st Century) Jacques Delors stated that "Excessive attraction to social sciences has broken equilibrium of available graduates for workforce, thus causing doubts of graduates and employers on the quality of knowledge provided by higher education". Likewise, when discussing the progress of science and technology, the 1998 UNESCO World Conference on Higher Education concluded that "Another challenge concerts the latest advancements of Science, the sine qua non of sustainable development"; and that “with Information Technology, the unavoidable invasion of virtual reality has increased the distance between industrial and developing countries". Recreational Science has a long tradition all over the Educational World; it aims to show the basic aspects of Science, aims to entertain, and aims to induce thinking. Until a few years ago, this field of knowledge consisted of a few books, a few kits and other classical (yet innovative) ways to popularize the knowledge of Nature and the laws governing it. In Spain, the interest for recreational science has increased in the last years. First, new recreational books are being published and found in bookstores. Second the number of Science-related museums and exhibits is increasing. And third, new television shows are produced and new short science-based, superficial sketches are found in variety programs. However, actual programs in Spanish television dealing seriously with Science are scarce. Recreational Science, especially that related to physical phenomena like light or motion, is generally found at Science Museums because special equipment is required. On the contrary, Science related mathematics, quizzes and puzzles use to gather into books, e.g. the extensive collections by Martin Gardner. However, lately Science podcasts have entered the field of science communication. Not only traditional science journals and television channels are providing audio and video podcasts, but new websites deal exclusively with science podcasts, in particular on Recreational Science. In this communication we discuss the above mentioned trends and show our experience in the last two years in participating at Science Fairs and university-sponsored events to attract students to science and technology careers. We show a combination of real examples (e.g., mathemagic), imagination, use of information technology, and use of social networks. We present as well an experience on designing a computational, interactive tool to promote chemistry among high school, prospective students using computers ("Dancing with Bionanomolecules"). Like the concepts related to Web 2.0, it has been already proposed that a new framework for communication of science is emerging, i.e., Science Communication 2.0, where people and institutions develop new innovative ways to explain science topics to diverse publics – and where Recreational Science is likely to play a leading role

Efficient learning of reactive robot behaviors with a Neural-Q_learning approach

The purpose of this paper is to propose a Neural-Q_learning approach designed for online learning of simple and reactive robot behaviors. In this approach, the Q_function is generalized by a multi-layer neural network allowing the use of continuous states and actions. The algorithm uses a database of the most recent learning samples to accelerate and guarantee the convergence. Each Neural-Q_learning function represents an independent, reactive and adaptive behavior which maps sensorial states to robot control actions. A group of these behaviors constitutes a reactive control scheme designed to fulfill simple missions. The paper centers on the description of the Neural-Q_learning based behaviors showing their performance with an underwater robot in a target following task. Real experiments demonstrate the convergence and stability of the learning system, pointing out its suitability for online robot learning. Advantages and limitations are discussed

Autonomous underwater vehicle control using reinforcement learning policy search methods

Autonomous underwater vehicles (AUV) represent a challenging control problem with complex, noisy, dynamics. Nowadays, not only the continuous scientific advances in underwater robotics but the increasing number of subsea missions and its complexity ask for an automatization of submarine processes. This paper proposes a high-level control system for solving the action selection problem of an autonomous robot. The system is characterized by the use of reinforcement learning direct policy search methods (RLDPS) for learning the internal state/action mapping of some behaviors. We demonstrate its feasibility with simulated experiments using the model of our underwater robot URIS in a target following task

Perspectives of auto-correcting lens distortions in mosaic-based underwater navigation

When unmanned underwater vehicles (UUVs) perform missions near the ocean floor, optical sensors can be used to improve local navigation. Video mosaics allow to efficiently process the images acquired by the vehicle, and also to obtain position estimates. We discuss in this paper the role of lens distortions in this context, proving that degenerate mosaics have their origin not only in the selected motion model or in registration errors, but also in the cumulative effect of radial distortion residuals. Additionally, we present results on the accuracy of different feature-based approaches for self-correction of lens distortions that may guide the choice of appropriate techniques for correcting distortions

Mission control system for dam inspection with an AUV

This paper presents a complete control architecture that has been designed to fulfill predefined missions with an autonomous underwater vehicle (AUV). The control architecture has three levels of control: mission level, task level and vehicle level. The novelty of the work resides in the mission level, which is built with a Petri network that defines the sequence of tasks that are executed depending on the unpredictable situations that may occur. The task control system is composed of a set of active behaviours and a coordinator that selects the most appropriate vehicle action at each moment. The paper focuses on the design of the mission controller and its interaction with the task controller. Simulations, inspired on an industrial underwater inspection of a dam grate, show the effectiveness of the control architecture

On AUV control architecture

This paper surveys control architectures proposed in the literature and describes a control architecture that is being developed for a semi-autonomous underwater vehicle for intervention missions (SAUVIM) at the University of Hawaii. Conceived as hybrid, this architecture has been organized in three layers: planning, control and execution. The mission is planned with a sequence of subgoals. Each subgoal has a related task supervisor responsible for arranging a set of pre-programmed task modules in order to achieve the subgoal. Task modules are the key concept of the architecture. They are the main building blocks and can be dynamically re-arranged by the task supervisor. In our architecture, deliberation takes place at the planning layer while reaction is dealt through the parallel execution of the task modules. Hence, the system presents both a hierarchical and an heterarchical decomposition, being able to show a predictable response while keeping rapid reactivity to the dynamic environment

Arqueología micropolítica del discurso bibliotecario. La biblioteca escolar ecológica productora de nueva subjetividad : su efecto en las redes sociales y bases de datos documentales.

El análisis micropolítico de los Discursos Bibliotecarios (DB) desinviste a las maquinas codificadoras de las misiones, que la institución bibliotecaria reproduce como valor agregado ligado a un modo de ser con base territorial; desmonta las máquinas axiomáticas de los manifiestos bibliotecarios que producen un valor agregado incluyendo forzadamente como deudores de conocimiento a los que no dominan el saber acumulado; y revela el valor agregado del capitalismo mundial integrado (CMI) que instaura procedimientos tácticos cada vez mas autoreferenciales (normas, pautas y directrices). En oposición a esos dispositivos de alineación, culpabilización, responsabilización y control, proponemos un proceso de singularización bibliotecaria en función de la producción de información ambiental en una Biblioteca Escolar Ecológica en conexión con redes sociales y bases de datos documentales.

Balance de política exterior del presidente Luis Inácio Lula Da Silva dentro del proyecto brasileño de liderazgo global. Periodo 2003-2010

La investigación se basa en el estudio de la política exterior brasileña para analizar el periodo de estudio. En una primera parte es relevante encontrar los patrones tanto de formulación como de implementación de la política exterior brasileña. Luego se revisan las agendas multilaterales, bilaterales y con las potencias emergentes. Finalmente se presenta un análisis de la apertura de representaciones diplomáticas en el periodo de estudio.

“Incidencia de la misión de paz enviada a Darfur “Misión de la Unión Africana en Sudán (AMIS)”, sobre la efectividad de la Unión Africana como Organización Internacional. (2004-2008)”

La incapacidad de la Misión de la Unión Africana en Sudan (AMIS) para pacificar Darfur, permitió que el conflicto avanzara sin que se tomasen medidas realmente efectivas, lo cual evidenció problemas estructurales de la Unión Africana que no permiten cumplir plenamente con los propósitos de la integración, principalmente con el de convertirse en garante de paz y seguridad. Como resultado, su efectividad empezó a ser cuestionada y se perdió la confianza en las misiones posteriores, al mismo tiempo que se vio afectada su imagen en medio del proceso de consolidación como la organización internacional más representativa del continente africano.

Misiones católicas en América Latina, siglos XIX-XX : estudio preliminar para una historia comparada

Este documento propone una aproximación preliminar al desarrollo de los estudios y las investigaciones históricas sobre los misioneros católicos en América Latina, en los finales del siglo xix y la primera mitad del siglo xx. Se estudian tres puntos de vista para establecer por medio de ellos diferentes marcos teóricos y métodos de investigación. (En los textos que serán abordados se presentan la investigación de corte vertical y transversal.) El estudio sobre las misiones católicas intenta proporcionar herramientas para adelantar un trabajo en historia comparada.

Aporte a la toma de decisiones Del Instituto de Ortopedia Infantil Roosevelt a partir del análisis estructural del sector estratégico de hospitales universitarios

El concepto de hospitales universitarios ha ido evolucionando en el mundo, siendo cada vez más estricta la legislación que los regula y los mecanismos de evaluación para asegurar la calidad de la educación a los estudiantes que realizan prácticas en ambientes hospitalarios. El direccionamiento estratégico de los hospitales universitarios requiere en primer lugar de un análisis específico del sector, mediante pruebas como el análisis de hacinamiento, levantamiento del panorama competitivo, el análisis estructural de las fuerzas de mercado y un estudio de competidores que permitan el diagnóstico del sector estratégico. Por otro lado la realización de un modelo matricial aportará a la planificación estratégica mediante la integración del análisis cuantitativo y cualitativo. La presente investigación busca analizar el sector estratégico de hospitales universitarios y de manera particular la situación del Instituto de Ortopedia Infantil Roosevelt como integrante del sector. En primer lugar se realizó una investigación del concepto de hospitales universitarios en el tiempo, tanto a nivel nacional como internacional y de la legislación existente. Posteriormente se identificaron las instituciones que constituyen el sector estratégico y se realizó el análisis del medioambiente empresarial para la identificación de la situación real del sector y un análisis particular del área de educación e investigación del Instituto de Ortopedia Infantil Roosevelt, para construir las estrategias y el horizonte institucional.

Análisis del efecto de engranaje generado por la entrada en vigor del Tratado de Lisboa el 1 de diciembre de 2009 en el marco de la Política Común de Seguridad y Defensa (PCSD) en la Unión Europea

El proceso de integración en Unión Europea se caracteriza por la incorporación de los asuntos de seguridad exterior y defensa, tras el Tratado de Lisboa se enmarcaron en la PCSD. Dicha política por un proceso de integración progresiva, Spillover, ha tenido periodos de reactivación y de letargos.

El problema de conceptualización del terrorismo dentro de la disciplina de las Relaciones Internacionales: Un análisis desde la perspectiva histórico conceptual

Los hechos ocurridos durante el 11 de septiembre de 2001 se constituyeron como un momento fundamental en los intentos de conceptualización del terrorismo internacional dentro de la disciplina de las Relaciones Internacionales. A raíz del 9/11 tuvo lugar la resemantización del concepto de terrorismo internacional en función del terrorismo religioso y del fundamentalismo islámico. Lo anterior, marco una ruptura en el campo de experiencia y en el horizonte de expectativas del concepto mismo, pues este último adquirió un nuevo uso discursivo, y por ende, político. Por eso, ante la necesidad de emprender un análisis discursivo de los usos del concepto de terrorismo internacional, se evidencia cómo al estar inmersos en determinados juegos del lenguaje, el uso discursivo de este concepto termina por convertirse en una herramienta de acción política que promueve una forma de vida.