14 research outputs found

    Generating walking behaviours in legged robots

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    Many legged robots have boon built with a variety of different abilities, from running to liopping to climbing stairs. Despite this however, there has been no consistency of approach to the problem of getting them to walk. Approaches have included breaking down the walking step into discrete parts and then controlling them separately, using springs and linkages to achieve a passive walking cycle, and even working out the necessary movements in simulation and then imposing them on the real robot. All of these have limitations, although most were successful at the task for which they were designed. However, all of them fall into one of two categories: either they alter the dynamics of the robots physically so that the robot, whilst very good at walking, is not as general purpose as it once was (as with the passive robots), or they control the physical mechanism of the robot directly to achieve their goals, and this is a difficult task.In this thesis a design methodology is described for building controllers for 3D dynam¬ ically stable walking, inspired by the best walkers and runners around — ourselves — so the controllers produced are based 011 the vertebrate Central Nervous System. This means that there is a low-level controller which adapts itself to the robot so that, when switched on, it can be considered to simulate the springs and linkages of the passive robots to produce a walking robot, and this now active mechanism is then controlled by a relatively simple higher level controller. This is the best of both worlds — we have a robot which is inherently capable of walking, and thus is easy to control like the passive walkers, but also retains the general purpose abilities which makes it so potentially useful.This design methodology uses an evolutionary algorithm to generate low-level control¬ lers for a selection of simulated legged robots. The thesis also looks in detail at previous walking robots and their controllers and shows that some approaches, including staged evolution and hand-coding designs, may be unnecessary, and indeed inappropriate, at least for a general purpose controller. The specific algorithm used is evolutionary, using a simple genetic algorithm to allow adaptation to different robot configurations, and the controllers evolved are continuous time neural networks. These are chosen because of their ability to entrain to the movement of the robot, allowing the whole robot and network to be considered as a single dynamical system, which can then be controlled by a higher level system.An extensive program of experiments investigates the types of neural models and net¬ work structures which are best suited to this task, and it is shown that stateless and simple dynamic neural models are significantly outperformed as controllers by more complex, biologically plausible ones but that other ideas taken from biological systems, including network connectivities, are not generally as useful and reasons for this are examined.The thesis then shows that this system, although only developed 011 a single robot, is capable of automatically generating controllers for a wide selection of different test designs. Finally it shows that high level controllers, at least to control steering and speed, can be easily built 011 top of this now active walking mechanism

    Advances in Robot Navigation

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    Robot navigation includes different interrelated activities such as perception - obtaining and interpreting sensory information; exploration - the strategy that guides the robot to select the next direction to go; mapping - the construction of a spatial representation by using the sensory information perceived; localization - the strategy to estimate the robot position within the spatial map; path planning - the strategy to find a path towards a goal location being optimal or not; and path execution, where motor actions are determined and adapted to environmental changes. This book integrates results from the research work of authors all over the world, addressing the abovementioned activities and analyzing the critical implications of dealing with dynamic environments. Different solutions providing adaptive navigation are taken from nature inspiration, and diverse applications are described in the context of an important field of study: social robotics

    Fourth Conference on Artificial Intelligence for Space Applications

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    Proceedings of a conference held in Huntsville, Alabama, on November 15-16, 1988. The Fourth Conference on Artificial Intelligence for Space Applications brings together diverse technical and scientific work in order to help those who employ AI methods in space applications to identify common goals and to address issues of general interest in the AI community. Topics include the following: space applications of expert systems in fault diagnostics, in telemetry monitoring and data collection, in design and systems integration; and in planning and scheduling; knowledge representation, capture, verification, and management; robotics and vision; adaptive learning; and automatic programming

    Conference on Intelligent Robotics in Field, Factory, Service, and Space (CIRFFSS 1994), volume 1

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    The AIAA/NASA Conference on Intelligent Robotics in Field, Factory, Service, and Space (CIRFFSS '94) was originally proposed because of the strong belief that America's problems of global economic competitiveness and job creation and preservation can partly be solved by the use of intelligent robotics, which are also required for human space exploration missions. Individual sessions addressed nuclear industry, agile manufacturing, security/building monitoring, on-orbit applications, vision and sensing technologies, situated control and low-level control, robotic systems architecture, environmental restoration and waste management, robotic remanufacturing, and healthcare applications

    Contemporary Robotics

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    This book book is a collection of 18 chapters written by internationally recognized experts and well-known professionals of the field. Chapters contribute to diverse facets of contemporary robotics and autonomous systems. The volume is organized in four thematic parts according to the main subjects, regarding the recent advances in the contemporary robotics. The first thematic topics of the book are devoted to the theoretical issues. This includes development of algorithms for automatic trajectory generation using redudancy resolution scheme, intelligent algorithms for robotic grasping, modelling approach for reactive mode handling of flexible manufacturing and design of an advanced controller for robot manipulators. The second part of the book deals with different aspects of robot calibration and sensing. This includes a geometric and treshold calibration of a multiple robotic line-vision system, robot-based inline 2D/3D quality monitoring using picture-giving and laser triangulation, and a study on prospective polymer composite materials for flexible tactile sensors. The third part addresses issues of mobile robots and multi-agent systems, including SLAM of mobile robots based on fusion of odometry and visual data, configuration of a localization system by a team of mobile robots, development of generic real-time motion controller for differential mobile robots, control of fuel cells of mobile robots, modelling of omni-directional wheeled-based robots, building of hunter- hybrid tracking environment, as well as design of a cooperative control in distributed population-based multi-agent approach. The fourth part presents recent approaches and results in humanoid and bioinspirative robotics. It deals with design of adaptive control of anthropomorphic biped gait, building of dynamic-based simulation for humanoid robot walking, building controller for perceptual motor control dynamics of humans and biomimetic approach to control mechatronic structure using smart materials

    Proceedings of the NASA Conference on Space Telerobotics, volume 1

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    The theme of the Conference was man-machine collaboration in space. Topics addressed include: redundant manipulators; man-machine systems; telerobot architecture; remote sensing and planning; navigation; neural networks; fundamental AI research; and reasoning under uncertainty

    Where is cognition? Towards an embodied, situated, and distributed interactionist theory of cognitive activity

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    In recent years researchers from a variety of cognitive science disciplines have begun to challenge some of the core assumptions of the dominant theoretical framework of cognitivism including the representation-computational view of cognition, the sense-model-plan-act understanding of cognitive architecture, and the use of a formal task description strategy for investigating the organisation of internal mental processes. Challenges to these assumptions are illustrated using empirical findings and theoretical arguments from the fields such as situated robotics, dynamical systems approaches to cognition, situated action and distributed cognition research, and sociohistorical studies of cognitive development. Several shared themes are extracted from the findings in these research programmes including: a focus on agent-environment systems as the primary unit of analysis; an attention to agent-environment interaction dynamics; a vision of the cognizer's internal mechanisms as essentially reactive and decentralised in nature; and a tendency for mutual definitions of agent, environment, and activity. It is argued that, taken together, these themes signal the emergence of a new approach to cognition called embodied, situated, and distributed interactionism. This interactionist alternative has many resonances with the dynamical systems approach to cognition. However, this approach does not provide a theory of the implementing substrate sufficient for an interactionist theoretical framework. It is suggested that such a theory can be found in a view of animals as autonomous systems coupled with a portrayal of the nervous system as a regulatory, coordinative, and integrative bodily subsystem. Although a number of recent simulations show connectionism's promise as a computational technique in simulating the role of the nervous system from an interactionist perspective, this embodied connectionist framework does not lend itself to understanding the advanced 'representation hungry' cognition we witness in much human behaviour. It is argued that this problem can be solved by understanding advanced cognition as the re-use of basic perception-action skills and structures that this feat is enabled by a general education within a social symbol-using environment

    Robotics 2010

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    Without a doubt, robotics has made an incredible progress over the last decades. The vision of developing, designing and creating technical systems that help humans to achieve hard and complex tasks, has intelligently led to an incredible variety of solutions. There are barely technical fields that could exhibit more interdisciplinary interconnections like robotics. This fact is generated by highly complex challenges imposed by robotic systems, especially the requirement on intelligent and autonomous operation. This book tries to give an insight into the evolutionary process that takes place in robotics. It provides articles covering a wide range of this exciting area. The progress of technical challenges and concepts may illuminate the relationship between developments that seem to be completely different at first sight. The robotics remains an exciting scientific and engineering field. The community looks optimistically ahead and also looks forward for the future challenges and new development

    Artificial societies and information theory: modelling of sub system formation based on Luhmann's autopoietic theory

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    This thesis develops a theoretical framework for the generation of artificial societies. In particular it shows how sub-systems emerge when the agents are able to learn and have the ability to communicate. This novel theoretical framework integrates the autopoietic hypothesis of human societies, formulated originally by the German sociologist Luhmann, with concepts of Shannon's information theory applied to adaptive learning agents. Simulations were executed using Multi-Agent-Based Modelling (ABM), a relatively new computational modelling paradigm involving the modelling of phenomena as dynamical systems of interacting agents. The thesis in particular, investigates the functions and properties necessary to reproduce the paradigm of society by using the mentioned ABM approach. Luhmann has proposed that in society subsystems are formed to reduce uncertainty. Subsystems can then be composed by agents with a reduced behavioural complexity. For example in society there are people who produce goods and other who distribute them. Both the behaviour and communication is learned by the agent and not imposed. The simulated task is to collect food, keep it and eat it until sated. Every agent communicates its energy state to the neighbouring agents. This results in two subsystems whereas agents in the first collect food and in the latter steal food from others. The ratio between the number of agents that belongs to the first system and to the second system, depends on the number of food resources. Simulations are in accordance with Luhmann, who suggested that adaptive agents self-organise by reducing the amount of sensory information or, equivalently, reducing the complexity of the perceived environment from the agent's perspective. Shannon's information theorem is used to assess the performance of the simulated learning agents. A practical measure, based on the concept of Shannon's information ow, is developed and applied to adaptive controllers which use Hebbian learning, input correlation learning (ICO/ISO) and temporal difference learning. The behavioural complexity is measured with a novel information measure, called Predictive Performance, which is able to measure at a subjective level how good an agent is performing a task. This is then used to quantify the social division of tasks in a social group of honest, cooperative food foraging, communicating agents

    Bodies in place : enactive cognition as development of ecological norms

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    Les partisans de l’approche énactive soutiennent que la cognition se constitue à travers l’histoire des différentes formes d'interaction (biologique, sensorimotrice, intercorporelle, linguistique, etc.) entre un vivant et son environnement. Ces interactions ne sont pas aléatoires, mais des activités obéissant à certaines normes que les énactivistes appellent sense-making. La cognition est, de ce point de vue, une forme de sense-making. Malgré les avantages indéniables que confère une telle perspective pour étudier la cognition, la présente thèse développe un point de vue critique par rapport à l’approche énactive et soutient qu'il est nécessaire d'approfondir notre compréhension de la dimension écologique du sense-making. Le but principal de la thèse est en conséquence de montrer que l'environnement joue un rôle encore plus important que l’approche énactive ne lui attribue habituellement. En m'engageant de manière critique dans le répertoire conceptuel de la cognition énactive, de la phénoménologie et des approches écologiques de la cognition, l’objectif de cette thèse consiste à poser les bases conceptuelles d'une approche énactive-écologique de la cognition. Pour ce faire, la thèse s’attèle à mettre de l’avant trois idées principales. La première consiste à redéfinir le concept du sense-making : contrairement à la conception qui s’est traditionnellement imposée dans le mouvement énactif, nous allons démontrer qu’il s’agit d’un phénomène de développement (et non de création) de normes. La rencontre du corps et du monde est toujours ancrée dans un champ normatif prédéfini, de sorte que nous devons réévaluer le rôle que joue l'environnement dans les processus de sense-making. En effet, si les agents se retrouvent toujours-déjà plongés dans un champ normatif (et non dans un environnement purement causal et physique), il faut alors reconnaître que l'environnement joue un rôle actif dans la constitution et l'auto-transformation des normes de sense-making. La deuxième idée poursuit dans cette veine et porte sur cette nouvelle conception de l'environnement, qui est ici défini comme un champ normatif actif, incarnant une tension entre le passé habituel du système agent-environnement et les contingences incessantes des événements du monde qui poussent le système vers leur auto-transformation et développement. La troisième idée principale de cette thèse consiste en une description holistique du champ d'action des agents (un lieu énactif) et des normes édictées (enacted) par des processus de sense-making sur le terrain (normes de lieu). Une esquisse générale du lieu énactif montre que les activités de sense-making sont liées à des processus écologiques qui enchevêtrent de multiples agents et localités matérielles dans un réseau écologique local. Ces réseaux écologiques forment une unité systémique et résiliente qui se déploie dans le temps avec les habitants du lieu, et fonctionne comme un champ normatif qui contraint et motive l'auto-transformation de chaque système agent-environnementSupporters of autonomist enactivism or the enactive approach claim that cognition is a phenomenon constituted by the historical development of different forms of interaction (biological, sensorimotor, intercorporeal, and linguistic) between living bodies and their environments. For autonomist enactivists, the nature of these interactions is not entirely predetermined by general laws of causation but by norms enacted in the historical path of the agent-environment system, and thanks to processes of sense-making. Cognition is, from the enactivist standpoint, a form of sense-making. While there are multiple advantages in holding such perspective to study mind and cognition, this thesis develops a critical point of view and argues that it is necessary to deepen our understanding of the ecological dimension of sense-making. Specifically, the thesis aims to show that the environment plays a more critical role than autonomist enactivism usually attributes to it. By drawing on and critically engaging with the conceptual repertoire of enactive cognition, phenomenology, and ecological approaches to cognition, my objective is to set the conceptual foundations for an enactive-ecological approach to cognition. For this task, I propose three interrelated ideas. The first redefines sense-making as a phenomenon of norm development. The most common descriptions of sense-making involve the emergence of meaning from raw physical matter thanks to the activity of living organisms. As norm development, by contrast, sense-making refers to a constant enactment and re-enactment of norms of interaction from other pregiven norms, previously enacted in the past of the agent-environment system. I argue that the encounter of the body and the world is permanently embedded in a pregiven normative field and never in an abstract void where raw physical interactions occur. From this standpoint, we need, however, to re-evaluate the role that the environment plays in sense-making processes. If agents find themselves immersed in normative fields and not in raw physical landscapes, then the environment has a more active role for the constitution and self-transformation of sense-making norms than autonomist enactivists have acknowledged. In this vein, the second main idea of this thesis concerns the environment as an active normative field that incarnates a tension between the habitual past of the agent-environment system and the ongoing contingencies of worldly events that push the system to their self-transformation and development. The third main idea of this thesis consists of a holistic description of the field of action of agents (enactive place) and the norms enacted by processes of sense-making in the field (place-norms). A general sketch of enactive place shows that sense-making is tied to processes that entangle multiple agents and material localities into a local ecological web. An enactive place constitutes a systemic and resilient unity that unfolds in time altogether with its inhabitants, working as a normative field that constrains and motivates the self-transformation of each agent-environment system. Bodies are therefore part of wider unities of historical development: places
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