Qualitative reasoning with directional relations

AbstractQualitative spatial reasoning (QSR) pursues a symbolic approach to reasoning about a spatial domain. Qualitative calculi are defined to capture domain properties in relation operations, granting a relation algebraic approach to reasoning. QSR has two primary goals: providing a symbolic model for human common-sense level of reasoning and providing efficient means for reasoning. In this paper, we dismantle the hope for efficient reasoning about directional information in infinite spatial domains by showing that it is inherently hard to decide consistency of a set of constraints that represents positions in the plane by specifying directions from reference objects. We assume that these reference objects are not fixed but only constrained through directional relations themselves. Known QSR reasoning methods fail to handle this information

Algebraic Properties of Qualitative Spatio-Temporal Calculi

Qualitative spatial and temporal reasoning is based on so-called qualitative calculi. Algebraic properties of these calculi have several implications on reasoning algorithms. But what exactly is a qualitative calculus? And to which extent do the qualitative calculi proposed meet these demands? The literature provides various answers to the first question but only few facts about the second. In this paper we identify the minimal requirements to binary spatio-temporal calculi and we discuss the relevance of the according axioms for representation and reasoning. We also analyze existing qualitative calculi and provide a classification involving different notions of a relation algebra.Comment: COSIT 2013 paper including supplementary materia

A survey of qualitative spatial representations

Representation and reasoning with qualitative spatial relations is an important problem in artificial intelligence and has wide applications in the fields of geographic information system, computer vision, autonomous robot navigation, natural language understanding, spatial databases and so on. The reasons for this interest in using qualitative spatial relations include cognitive comprehensibility, efficiency and computational facility. This paper summarizes progress in qualitative spatial representation by describing key calculi representing different types of spatial relationships. The paper concludes with a discussion of current research and glimpse of future work

Qualitative Spatial and Temporal Reasoning based on And/Or Linear Programming An approach to partially grounded qualitative spatial reasoning

Acting intelligently in dynamic environments involves anticipating surrounding processes, for example to foresee a dangerous situation or acceptable social behavior. Knowledge about spatial configurations and how they develop over time enables intelligent robots to safely navigate by reasoning about possible actions. The seamless connection of high-level deliberative processes to perception and action selection remains a challenge though. Moreover, an integration should allow the robot to build awareness of these processes as in reality there will be misunderstandings a robot should be able to respond to. My aim is to verify that actions selected by the robot do not violate navigation or safety regulations and thereby endanger the robot or others. Navigation rules specified qualitatively allow an autonomous agent to consistently combine all rules applicable in a context. Within this thesis, I develop a formal, symbolic representation of right-of-way-rules based on a qualitative spatial representation. This cumulative dissertation consists of 5 peer-reviewed papers and 1 manuscript under review. The contribution of this thesis is an approach to represent navigation patterns based on qualitative spatio-temporal representation and the development of corresponding effective sound reasoning techniques. The approach is based on a spatial logic in the sense of Aiello, Pratt-Hartmann, and van Benthem. This logic has clear spatial and temporal semantics and I demonstrate how it allows various navigation rules and social conventions to be represented. I demonstrate the applicability of the developed method in three different areas, an autonomous robotic system in an industrial setting, an autonomous sailing boat, and a robot that should act politely by adhering to social conventions. In all three settings, the navigation behavior is specified by logic formulas. Temporal reasoning is performed via model checking. An important aspect is that a logic symbol, such as \emph{turn left}, comprises a family of movement behaviors rather than a single pre-specified movement command. This enables to incorporate the current spatial context, the possible changing kinematics of the robotic system, and so on without changing a single formula. Additionally, I show that the developed approach can be integrated into various robotic software architectures. Further, an answer to three long standing questions in the field of qualitative spatial reasoning is presented. Using generalized linear programming as a unifying basis for reasoning, one can jointly reason about relations from different qualitative calculi. Also, concrete entities (fixed points, regions fixed in shape and/or position, etc.) can be mixed with free variables. In addition, a realization of qualitative spatial description can be calculated, i.e., a specific instance/example. All three features are important for applications but cannot be handled by other techniques. I advocate the use of And/Or trees to facilitate efficient reasoning and I show the feasibility of my approach. Last but not least, I investigate a fourth question, how to integrate And/Or trees with linear temporal logic, to enable spatio-temporal reasoning

Multimodal Shared-Control Interaction for Mobile Robots in AAL Environments

This dissertation investigates the design, development and implementation of cognitively adequate, safe and robust, spatially-related, multimodal interaction between human operators and mobile robots in Ambient Assisted Living environments both from the theoretical and practical perspectives. By focusing on different aspects of the concept Interaction, the essential contribution of this dissertation is divided into three main research packages; namely, Formal Interaction, Spatial Interaction and Multimodal Interaction in AAL. As the principle package, in Formal Interaction, research effort is dedicated to developing a formal language based interaction modelling and management solution process and a unified dialogue modelling approach. This package aims to enable a robust, flexible, and context-sensitive, yet formally controllable and tractable interaction. This type of interaction can be used to support the interaction management of any complex interactive systems, including the ones covered in the other two research packages. In the second research package, Spatial Interaction, a general qualitative spatial knowledge based multi-level conceptual model is developed and proposed. The goal is to support a spatially-related interaction in human-robot collaborative navigation. With a model-based computational framework, the proposed conceptual model has been implemented and integrated into a practical interactive system which has been evaluated by empirical studies. It has been particularly tested with respect to a set of high-level and model-based conceptual strategies for resolving the frequent spatially-related communication problems in human-robot interaction. Last but not least, in Multimodal Interaction in AAL, attention is drawn to design, development and implementation of multimodal interaction for elderly persons. In this elderly-friendly scenario, ageing-related characteristics are carefully considered for an effective and efficient interaction. Moreover, a standard model based empirical framework for evaluating multimodal interaction is provided. This framework was especially applied to evaluate a minutely developed and systematically improved elderly-friendly multimodal interactive system through a series of empirical studies with groups of elderly persons

Principios matemáticos del comportamiento natural

[ES] Esta tesis doctoral se enmarca dentro de la búsqueda de una teoría científica que unifique los comportamientos de sistemas biológicos y no biológicos autónomos. Además, también aborda el desarrollo de algoritmos que permitan la creación de robots multifuncionales. El objetivo de la tesis ha sido investigar y desarrollar la teoría general del exocomportamiento. Ese objetivo se basa en dos motivos. Un motivo es el tener un marco para lograr una mejor comprensión de los comportamientos y sus efectos en la naturaleza. El segundo motivo es tener una guía en el desarrollo de nuevos métodos que doten a computadoras y robots de comportamientos complejos que les permitan integrarse en entornos humanos no específicos facilitando la vida cotidiana o ayudando en tareas peligrosas. El problema de encontrar una teoría fisicalista capaz de unificar los comportamientos se ha abordado investigando y desarrollando la teoría general del exocomportamiento. La teoría general del exocomportamiento se ha desarrollado buscando evitar los problemas que se han observado en teorías anteriores para explicar los comportamientos y que posea las características positivas que han tenido propuestas previas. Así, es interesante destacar que se evitan los conceptos mentalistas y se formulan desde un punto fisicalista. Una consecuencia inesperada de la formulación es que ha llevado a determinar que procesos ontogénicos y los comportamientos pertenecen al mismo conjunto de fenómenos, los exocomportamientos. Una característica destacable de la teoría general del exocomportamiento es que su formulación plantea una completa integración de los exocomportamietos con los procesos evolutivos. Además del papel de la teoría general del exocomportamiento como explicación, esta ha servido también de marco teórico en el que plantear preguntas sobre la naturaleza. Así, se han planteado preguntas sobre la evolución que han llevado a realizar una investigación sobre los modelos computacionales de los organismos multicelulares y las fuerzas evolutivas que los han conformado. Así, la teoría general del exocomportamiento ha mostrado las dos características que se espera de una teoría de unificación: explicar fenómenos y dirigir nuevas investigaciones. El problema de desarrollar métodos computacionales cualitativos que contribuyan a la creación de robots multifuncionales ha sido abordado proponiendo y desarrollando el programa de robots multifuncionales mediante nociones topológicas. Este programa de investigación tiene como objetivo desarrollar métodos cualitativos mediante el uso de nociones topológicas con las que definir relaciones espaciales cualitativas. Además del uso de nociones topológicas, se han usado elementos de la teoría cognitiva de condiciones de verdad. El programa afronta el desarrollo de métodos computacionales para desenvolverse en entornos y situaciones de manera gradual. Primero se intenta encontrar un método capaz de afrontar la situación más sencilla posible. Una vez que se ha obtenido un método efectivo, se plantea una situación más compleja, y se estudia si el método es efectivo o no. Si no lo es, se estudian cuáles son los problemas y se busca un nuevo método que sea efectivo y que cumpla con las condiciones que establece el programa. Los resultados del programa han mostrado que la línea de investigación de la creación de robots multifuncionales mediante nociones topológicas y condiciones de verdad es prometedora. Se ha logrado una arquitectura, denominada arquitectura de navegación cualitativa topológica 1.0, que permite la navegación en espacios desconocidos y dinámicos en los que las tomas de decisiones, los objetivos, y el conocimiento que almacena se hace de manera cualitativa. Un resultado interesante que se ha obtenido es un método para codificar información direccional en relaciones topológicas. Además, ese resultado ha servido para crear una heurística que permite tomar decisiones sobre giros y definir un sistema de coordenadas cualitativas esféricas que elimina algunas limitaciones que tenía el sistema de coordenadas cualitativas cartesiano construido al comienzo de la investigación. El último resultado que se ha obtenido es una técnica para generar expresiones de lenguaje natural sobre relaciones espaciales cualitativas que abre la puerta a una nueva fase para continuar investigando el desarrollo de robots multifuncionales basados en nociones topológicas y condiciones de verdad. Los resultados obtenidos en esta tesis llevan a concluir que tanto la teoría general del exocomportamiento como el programa de investigación de robots multifuncionales mediante nociones topológicas son sólidas líneas de investigación en la obtención de resultados para la unificación de los comportamientos y la creación de robots multifuncionales