ABC2 : un modelo para el control de robots autónomos

El objetivo de esta tesis doctoral es el diseño de un modelo para el control de robots autónomos. Su prinicipal aportación es la organización de la ejecución de tareas de alto nivel de forma oportunista, haciendo uso de controladores de bajo nivel. El modelo tiene también en consideración la posible existencia de otros robots en el mismo dominio, haciendo que sea posible la cooperación entre varios de ellos para la realización de tareas que se puedan beneficiar de la colaboración. La principal aportación de este trabajo es el diseño del mecanismo de control de las actividades de un robot. Dicho mecanismo está basado en la utilización de una agenda para la planificación de las acciones. Los elementos que se pueden insertar en esa agenda se denominan actos y representan acciones potenciales del robot. La generación de estos actos puede deberse a metas definidas para el robot, a peticiones de otros robots, o a eventos generados en el entorno. La política de gestión de la agenda está predefinida, pero puede modificarse mediante la definición de heurísticas de control. El modelo prevé también la integración entre las tareas a desarrollar individualmente en un robot y aquéllas que implican una colaboración entre robots. Para ello se ha diseñado un mecanismo de definición de las habilidades particulares de cada robot y otro de comunicación de las mismas a otros robots. El mecanismo de definición de habilidades permite la utilización de distintos paradigmas para su diseño, como la lógica borrosa, las redes neuronales, o el empleo de técnicas de aprendizaje automático. Este formalismo de definición proporciona un nivel de abstracción sobre su implementación que permite la difusión de la información sobre las habilidades de un robot entre distintos robots. Para comprobar la validez del modelo desarrollado se han realizado diversas aplicaciones, tanto con robots simulados como con robots reales. En la presente memoria se presentan y discuten las decisiones tomadas en el diseño del modelo y los resultados obtenidos en los experimentos realizados. Abstract The goal of this thesis is the design of a model for the control of autonomous robots. This model should allow the execution of high level tasks, using low level controllers. The existence of other robots in the same domain has also been considered. The model should provide mechanisms to let robots cooperate in tasks that require collaboration. The main contribution of this work is the design of the control mechanism of the robot tasks. This mechanism is based on the use of an agenda as the base for the planning of the robot activities. The items that can be inserted into the agenda are named acts. These acts represent potential actions that the robot can accomplish. The acts can be generated by the internal goals of the robot, by requests from other robots, or by events generated in the environment. The administration of the agenda is predefined, but it can be modified by the definition of control heuristic. The model also considers the integration of individual tasks and those that need collaboration with other robots. A mechanism for defining the particular skills of each robot has been defined, as well as a communication mechanism, in order to let the robot cooperate. The skills definition mechanism allows the use of different paradigms in its design, as for instance, fuzzy logic, neural networks or the use of machine learning techniques. This definition formalism provides an abstraction level over the implementation of the skills that allows the broadcasting of the information about the individual skills among different robots. In order to test the validation of the model, different applications have been developed. These applications involved simulated robots as well as real robots. This manuscript presents and discusses the decisions taken in the design of the model as well as the results obtained in the experiments

Portable Multi-Hypothesis Monte Carlo Localization for Mobile Robots

Self-localization is a fundamental capability that mobile robot navigation systems integrate to move from one point to another using a map. Thus, any enhancement in localization accuracy is crucial to perform delicate dexterity tasks. This paper describes a new location that maintains several populations of particles using the Monte Carlo Localization (MCL) algorithm, always choosing the best one as the sytems's output. As novelties, our work includes a multi-scale match matching algorithm to create new MCL populations and a metric to determine the most reliable. It also contributes the state-of-the-art implementations, enhancing recovery times from erroneous estimates or unknown initial positions. The proposed method is evaluated in ROS2 in a module fully integrated with Nav2 and compared with the current state-of-the-art Adaptive ACML solution, obtaining good accuracy and recovery times.Comment: Submission for ICRA 202

Uso de sistemas de control de versiones para aplicar estrategias de evaluación por pares en contextos tecnológicos [Using Version Control Systems to apply peer review techniques in engineering education]

Diferentes metodologías educativas han demostrado que un aspecto muy positivo para mejorar el aprendizaje del estudiante es que éste sea parte central del mismo, y especialmente que se involucre de manera activa en los procesos de aprendizaje. En este sentido la aplicación de técnicas de evaluación por pares ha sido una aproximación muy popular. Sin embargo, en enseñanzas de carácter ingenieril y especialmente enseñanzas técnicas, las actividades a evaluar implican en muchas ocasiones el uso de lenguajes o herramientas muy específicas. Esto hace que la evaluación por pares sea más compleja e implique que tanto alumnos como profesores tengan que utilizar diferentes contextos para la evaluación (como una herramienta de desarrollo software y una plataforma de aprendizaje). De cara a solventar este problema el presente trabajo propone el uso de sistemas de control de versiones que van a permitir almacenar los resultados obtenidos e interactuar al responsable del trabajo con sus revisores. En concreto, en este artículo se presenta la aplicación de técnicas de evaluación por pares en un grupo de 46 alumnos. Los resultados muestran que los discentes que usan activamente la herramienta con fines de evaluación tienen mejores resultados asociados. [Different studies have shown that a very positive factor to improve students learning is that they were the center of teaching and learning processes and also to be an active part in them. In this sense, the application of peer review techniques is a very popular approach. However, in engineering education and special in technical degrees the activities to assess consist of the use of very specific tools and languages. This makes peer evaluation more complex in this context than in others. It requires that both teachers and students use different tools and platforms to complete the evaluation. In order to solve this, the present work aims to apply a version control system to facilitate manage different results versions and also to interact with reviewers in the peer review process. In this specific work, the authors present a case study with 46 students that employ a version control system to apply peer review. Results show that students that use properly the tool have better performance.

ABC² An Agenda Based Multi-Agent Model for Robots Control and Cooperation

This paper presents a model for the control of autonomous robots that allows cooperation among them. The control structure is based on a general purpose multi-agent architecture based on an hybrid approach made up by two levels. One level is composed of reactive skills capable of achieving simple actions by their own. The other one uses an agenda used as an opportunistic planning mechanism to compound, activate and coordinate the basic skills. This agenda handles actions both from the internal goals of the robot or from other robots. This two level approach allows the integration of real-time response of reactive systems needed for robot low-level behavior, with a classical high level planning component that permits a goal oriented behavior. The paper describes the architecture itself, and its use in three different domains, including real robots, as well as the issues arising from its adaptation to the RoboCup simulator domain

Dynamic Gridmaps: Comparing Building Techniques

Mobile robots need to represent obstacles in their surroundings, even moving ones, to make right movement decisions. For higher autonomy the robot should automatically build such representation from its sensory input. This paper compares the dynamic character of several gridmap building techniques: probabilistic, fuzzy, theory of evidence and histogramic. Two criteria are defined to rank such dynamism in the representation: time to show a new obstacle and time to show a new hole. The update rules for first three such techniques hold associative property which confers them static character, inconvenient for dynamic environments. Two new approaches are presented to improve the perception of mobile obstacles: one uses a di#erential equation to update the map and another uses majority voting in a limited memory per cell. Their dynamisms are also evaluated

Using ABC² in the RoboCup Domain

This paper presents an architecture for the control of autonomus agents that allows explicit cooperation among them. The structure of the software agents controlling the robots is based on a general purpose multi-agent architecture based on a two level approach. One level is composed of reactive skills capable of achieving simple actions by their own. The other is based on an agenda used as an opportunistic planning mechanism to compound, activate and coordinate the basic skills