309 research outputs found
GPU Computing for Cognitive Robotics
This thesis presents the first investigation of the impact of GPU
computing on cognitive robotics by providing a series of novel experiments in
the area of action and language acquisition in humanoid robots and computer
vision. Cognitive robotics is concerned with endowing robots with high-level
cognitive capabilities to enable the achievement of complex goals in complex
environments. Reaching the ultimate goal of developing cognitive robots will
require tremendous amounts of computational power, which was until
recently provided mostly by standard CPU processors. CPU cores are
optimised for serial code execution at the expense of parallel execution, which
renders them relatively inefficient when it comes to high-performance
computing applications. The ever-increasing market demand for
high-performance, real-time 3D graphics has evolved the GPU into a highly
parallel, multithreaded, many-core processor extraordinary computational
power and very high memory bandwidth. These vast computational resources
of modern GPUs can now be used by the most of the cognitive robotics models
as they tend to be inherently parallel. Various interesting and insightful
cognitive models were developed and addressed important scientific questions
concerning action-language acquisition and computer vision. While they have
provided us with important scientific insights, their complexity and
application has not improved much over the last years. The experimental
tasks as well as the scale of these models are often minimised to avoid
excessive training times that grow exponentially with the number of neurons
and the training data. This impedes further progress and development of
complex neurocontrollers that would be able to take the cognitive robotics
research a step closer to reaching the ultimate goal of creating intelligent
machines. This thesis presents several cases where the application of the GPU
computing on cognitive robotics algorithms resulted in the development of
large-scale neurocontrollers of previously unseen complexity enabling the
conducting of the novel experiments described herein.European Commission Seventh Framework
Programm
Challenging the Computational Metaphor: Implications for How We Think
This paper explores the role of the traditional computational metaphor in our thinking as computer scientists, its influence on epistemological styles, and its implications for our understanding of cognition. It proposes to replace the conventional metaphor--a sequence of steps--with the notion of a community of interacting entities, and examines the ramifications of such a shift on these various ways in which we think
Visual object tracking performance measures revisited
The problem of visual tracking evaluation is sporting a large variety of
performance measures, and largely suffers from lack of consensus about which
measures should be used in experiments. This makes the cross-paper tracker
comparison difficult. Furthermore, as some measures may be less effective than
others, the tracking results may be skewed or biased towards particular
tracking aspects. In this paper we revisit the popular performance measures and
tracker performance visualizations and analyze them theoretically and
experimentally. We show that several measures are equivalent from the point of
information they provide for tracker comparison and, crucially, that some are
more brittle than the others. Based on our analysis we narrow down the set of
potential measures to only two complementary ones, describing accuracy and
robustness, thus pushing towards homogenization of the tracker evaluation
methodology. These two measures can be intuitively interpreted and visualized
and have been employed by the recent Visual Object Tracking (VOT) challenges as
the foundation for the evaluation methodology
Reasoning with BDI robots: from simulation to physical environment – implementations and limitations
In this paper an overview of the state of research into cognitive robots is given. This is driven by insights arising from research that has moved from simulation to physical robots over the course of a number of sub-projects. A number of major issues arising from seminal research in the area are explored. In particular in the context of advances in the field of robotics and a slowly developing model of cognition and behaviour that is being mapped onto robot colonies. The work presented is ongoing but major themes such as the veracity of data and information, and their effect on robot control architectures are explored. A small number of case studies are presented where the theoretical framework has been used to implement control of physical robots. The limitations of the current research and the wider field of behavioral and cognitive robots are explored
CoopDynSim : a 3D robotics simulator
This paper presents CoopDynSim, a multi-robot 3D
simulator. The main motivations for the development of a new
simulation software lie in the need to emulate specific, custom
made sensors, combined with the desire to smoothly transfer
controller code from simulation to real implementation. The
latter is achieved through the use of the same middleware layer
already implemented in the real platforms. The high modularity
of the solution allows the user to easily add new components or
design new platforms. By having independent simulation threads
for each robot, distributed control algorithms can easily be tested,
abetted by a socket based connection, granting the possibility
for an asynchronous, over the network, controller architecture.
The ability to run simulations in real or simulated time, as
well as a play back option, represent valuable features of the
software. The simulator has been used in several projects, with
different platforms and distinct control applications, proving it
as a heterogeneous and flexible solution. Furthermore, its usage
as a teaching tool in a robotics’ summer school as well as
in an introductory robotics class in our university, upholds its
simplicity and user-friendliness.Fundação para a Ciência e a Tecnologia (FCT) - ref. SFRH/BD/38885/200
Robot Navigation in Unseen Spaces using an Abstract Map
Human navigation in built environments depends on symbolic spatial
information which has unrealised potential to enhance robot navigation
capabilities. Information sources such as labels, signs, maps, planners, spoken
directions, and navigational gestures communicate a wealth of spatial
information to the navigators of built environments; a wealth of information
that robots typically ignore. We present a robot navigation system that uses
the same symbolic spatial information employed by humans to purposefully
navigate in unseen built environments with a level of performance comparable to
humans. The navigation system uses a novel data structure called the abstract
map to imagine malleable spatial models for unseen spaces from spatial symbols.
Sensorimotor perceptions from a robot are then employed to provide purposeful
navigation to symbolic goal locations in the unseen environment. We show how a
dynamic system can be used to create malleable spatial models for the abstract
map, and provide an open source implementation to encourage future work in the
area of symbolic navigation. Symbolic navigation performance of humans and a
robot is evaluated in a real-world built environment. The paper concludes with
a qualitative analysis of human navigation strategies, providing further
insights into how the symbolic navigation capabilities of robots in unseen
built environments can be improved in the future.Comment: 15 pages, published in IEEE Transactions on Cognitive and
Developmental Systems (http://doi.org/10.1109/TCDS.2020.2993855), see
https://btalb.github.io/abstract_map/ for access to softwar
REBA: A Refinement-Based Architecture for Knowledge Representation and Reasoning in Robotics
This paper describes an architecture for robots that combines the
complementary strengths of probabilistic graphical models and declarative
programming to represent and reason with logic-based and probabilistic
descriptions of uncertainty and domain knowledge. An action language is
extended to support non-boolean fluents and non-deterministic causal laws. This
action language is used to describe tightly-coupled transition diagrams at two
levels of granularity, with a fine-resolution transition diagram defined as a
refinement of a coarse-resolution transition diagram of the domain. The
coarse-resolution system description, and a history that includes (prioritized)
defaults, are translated into an Answer Set Prolog (ASP) program. For any given
goal, inference in the ASP program provides a plan of abstract actions. To
implement each such abstract action, the robot automatically zooms to the part
of the fine-resolution transition diagram relevant to this action. A
probabilistic representation of the uncertainty in sensing and actuation is
then included in this zoomed fine-resolution system description, and used to
construct a partially observable Markov decision process (POMDP). The policy
obtained by solving the POMDP is invoked repeatedly to implement the abstract
action as a sequence of concrete actions, with the corresponding observations
being recorded in the coarse-resolution history and used for subsequent
reasoning. The architecture is evaluated in simulation and on a mobile robot
moving objects in an indoor domain, to show that it supports reasoning with
violation of defaults, noisy observations and unreliable actions, in complex
domains.Comment: 72 pages, 14 figure
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