Building maps of large environments using splines and geometric analysis

Recently, a novel solution to the Simultaneous Localization and Map building (SLAM) problem for complex indoor environments was presented, using a set of splines for describing the geometries detected by a laser range finder mounted on a mobile platform. In this paper, a method for exploiting the geometric information underlying in these maps in the data association process is described. The proposed approach uses graphs of relations between simple features extracted from the environment, and a bit encoded implementation for obtaining a maximum clique that relates observations with previously visited areas. This information is used to update the relative positions of a collage of submaps of limited size

Sensitive Skin for Robotics

This thesis explores two novel ways of reducing the data complexity of tactile sensing. The thesis begins by examining the state-of-the art in tactile sensing, not only examining the sensor construction and interpretation of data but also the motivation for these designs. The thesis then proposes two methods for reducing the complexity of data in tactile sensing. The first is a low-power tactile sensing array exploiting a novel application of a pressure-sensitive material called quantum tunnelling composite. The properties of this material in this array form are shown to be beneficial in robotics. The electrical characteristics of the material are also explored. A bit-based structure for representing tactile data called Bitworld is then defined and its computational performance is characterised. It is shown that this bit-based structure outperforms floating-point arrays by orders of magnitude. This structure is then shown to allow high-resolution images to be produced by combining low resolution sensor arrays with equivalent functional performance to a floating-point array, but with the advantages of computational efficiency. Finally, an investigation into making Bitworld robust in the presence of positional noise is described with simulations to verify that such robustness can be achieved. Overall, the sensor and data structure described in this thesis allow simple, but effective tactile systems to be deployed in robotics without requiring a significant commitment of computational or power resources on the part of a robot designer.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

SpoookyJS. Ein multiagentenbasiertes JavaScript-Framework zur flexiblen Implementation digitaler browserbasierter Brettspiele und spielübergreifender künstlicher Intelligenz

Künstliche Intelligenz in digitalen Spielen ist zumeist Anwendungsdomäne komplexer spielspezifischer Softwarelösungen mangelnder Erweiterbarkeit. Die vorliegende Arbeit beschäftigt sich mit der Konzeption und Realisierung des JavaScript-Frameworks SpoookyJS, das die vereinfachte Erstellung browserbasierter digitaler Brettspiele ermöglicht. Entwickelt als Multiagentensystem, bietet SpoookyJS künstliche Gegner in den umgesetzten Spielen und fungiert als Test- und Entwicklungsumgebung für die Forschung um spielübergreifende artifizielle Entscheidungsfindung

Concepts and concreteness in psycholinguistics

This thesis is about the concrete-abstract distinction (‘concreteness’) as it applies in psycholinguistic research and theories of concepts. Concreteness is one of the most-investigated psycholinguistic variables, and is also the basis for major disputes about the nature of the human conceptual system. However, I argue that concreteness is not actually a useful construct, and that the units of the conceptual system do not neatly match up with words of natural language, as is often assumed in the experimental and theoretical literatures. I dispute evidence for ‘concreteness effects’, whereby words with high concreteness ratings exhibit processing differences relative to words with low concreteness ratings. The concreteness measure itself has statistical properties that invalidate it as a psycholinguistic tool. I report four new experiments designed to take into account these troublesome statistical properties, and maximise the chances of finding a concreteness effect. Counterintuitively, in three out of four experiments, the effect disappeared, and in the fourth it was extremely small. I suggest that evidence for concreteness effects is not as strong as it appears to be. Furthermore, even if the effects are real, current explanations of them still fail in various ways. I also consider how the concrete-abstract distinction intersects with popular theories of concepts and cognition, with an emphasis on two in particular (a Fodorian Language of Thought, and a Barsalou-ian Simulator theory). Using the alleged ‘abstract’ concept JUSTICE as an example, I argue that from the point of view of these theories, some abstract concepts are explanatorily vacuous: they do not actually offer any insight into behaviour or cognition. I conclude that although many ‘concrete’ items belong in our theories of concepts, some alleged ‘abstract’ concepts aren’t concepts at all. I explore some positive implications of this conclusion for theories of word meaning, and for theories of concepts in general