97 research outputs found
Menge: A Modular Framework for Simulating Crowd Movement
We present Menge, a cross-platform, extensible, modular framework for simulating pedestrian movement in a crowd. Menge's architecture is inspired by an implicit decomposition of the problem of simulating crowds into component subproblems. These subproblems can typically be solved in many ways; different combinations of subproblem solutions yield crowd simulators with likewise varying properties. Menge creates abstractions for those subproblems and provides a plug-in architecture so that a novel simulator can be dynamically configured by connecting built-in and bespoke implementations of solutions to the various subproblems. Use of this type of framework could facilitate crowd simulation research, evaluation, and applications by reducing the cost of entering the domain, facilitating collaboration, and making comparisons between algorithms simpler. We show how the Menge framework is compatible with many prior models and algorithms used in crowd simulation and illustrate its flexibility via a varied set of scenarios and applications
Developing a person guidance module for hospital robots
This dissertation describes the design and implementation of the Person Guidance Module (PGM) that enables the IWARD (Intelligent Robot Swarm for attendance, Recognition, Cleaning and delivery) base robot to offer route guidance service to the patients or visitors inside the hospital arena. One of the common problems encountered in huge hospital buildings today is foreigners not being able to find their way around in the hospital. Although there are a variety of guide robots currently existing on the market and offering a wide range of guidance and related activities, they do not fit into the modular concept of the IWARD project. The PGM features a robust and foolproof non-hierarchical sensor fusion approach of an active RFID, stereovision and cricket mote sensor for guiding a patient to the X-ray room, or a visitor to a patient’s ward in every possible scenario in a complex, dynamic and crowded hospital environment. Moreover, the speed of the robot can be adjusted automatically according to the pace of the follower for physical comfort using this system. Furthermore, the module performs these tasks in any unconstructed environment solely from a robot’s onboard perceptual resources in order to limit the hardware installation costs and therefore the indoor setting support. Similar comprehensive solution in one single platform has remained elusive in existing literature. The finished module can be connected to any IWARD base robot using quick-change mechanical connections and standard electrical connections. The PGM module box is equipped with a Gumstix embedded computer for all module computing which is powered up automatically once the module box is inserted into the robot. In line with the general software architecture of the IWARD project, all software modules are developed as Orca2 components and cross-complied for Gumstix’s XScale processor. To support standardized communication between different software components, Internet Communications Engine (Ice) has been used as middleware. Additionally, plug-and-play capabilities have been developed and incorporated so that swarm system is aware at all times of which robot is equipped with PGM. Finally, in several field trials in hospital environments, the person guidance module has shown its suitability for a challenging real-world application as well as the necessary user acceptance
Improve the Performance of Industrial Agents using Fog Computing
In the last decade, the market requirements have been increasing by demanding
numerous different products being highly customizable. Given this need, the necessity
for dynamic and flexible production lines are a high priority to meet this change.
A traditional approach is not enough to meet the market demand and due to this,
several paradigms have been coined out to try and solve this problem. The proposed
approach is related to communication between the shop-floor modules in order to create
different products.
This work proposes an architecture where an integration layer will join a Multiagent
System capable of the more recent production paradigms with legacy hardware that
is present in the more traditional factories in order to have different products being
produced in the same production line.
This architecture that revolves an interface that can be used by the agents in the
factory in order to use the hardware modules to create a different product if need be.
The main features of this project is the fact that by using datamodels and an interface
created, it can be easily plugged new stations with different tools to modify the product
thus increasing the amount of products that can be created
Modern Information Systems
The development of modern information systems is a demanding task. New technologies and tools are designed, implemented and presented in the market on a daily bases. User needs change dramatically fast and the IT industry copes to reach the level of efficiency and adaptability for its systems in order to be competitive and up-to-date. Thus, the realization of modern information systems with great characteristics and functionalities implemented for specific areas of interest is a fact of our modern and demanding digital society and this is the main scope of this book. Therefore, this book aims to present a number of innovative and recently developed information systems. It is titled "Modern Information Systems" and includes 8 chapters. This book may assist researchers on studying the innovative functions of modern systems in various areas like health, telematics, knowledge management, etc. It can also assist young students in capturing the new research tendencies of the information systems' development
Semantic-based adaptive mission planning for unmanned underwater vehicles
Current underwater robotic platforms rely upon waypoint-based scripted missions which
are described by the operator a-priori. This renders systems incapable of reacting to
the unexpected. In this thesis, we claim that the ability to autonomously adapt the
decision making process is the key to facilitating the change over from human intervention
to intelligent autonomy. We identify goal-based declarative mission planning
as an attractive solution to autonomous adaptability because it combines autonomous
decision making with higher levels of human interaction.
Goal-based mission planning requires the use of abstract knowledge representation
and situation awareness to link the prior knowledge provided by the operator with
the information coming from the processed sensor data. To achieve this, we propose
a semantic-based knowledge representation framework that allows this integration of
prior and processed information among all different agents available in the platform.
In order to evaluate adaptive mission planning techniques, we also introduce a novel
metric which measures the proximity between plans. We demonstrate that this metric
is better informed than previous metrics for measuring the adaptation process.
In this thesis we implement three different approaches to goal-based mission planning
in order to investigate which approach is most appropriate under different circumstances.
The first approach, continuous mission planning, focusses on long-term
deployment. This approach is based on a continuous re-assessment of the status of
the mission environment. Using our proximity metric, we evaluated this approach
and show that there is a high degree of similarity between our approach and the humanly
driven adaptation, both in a known static environment and in a partially-known
dynamic discoverable environment. The second, service-oriented mission planning,
makes use of the semantic framework to provide autonomous mission planning for
the dynamic discovery of the services published by the different agents in the system.
This allows platform independence, easing the manual creation of mission plans, and
robustness to changes. We show that this approach produces the same plans as the
baseline which was explicitly provided with the platform configuration. The last approach,
mission plan repair, handles the scenario where small changes occur in the
mission environment and there are limited resources for planning. We develop and
deploy a mission plan repair approach within a semantic-based autonomous planning
system in a real underwater vehicle. Experiments demonstrate that the integrated system
is capable of providing mission adaptation for maintaining the operability of the
host platform in the face of unexpected events
Arquitectura para coordenação em tempo-real de múltiplas unidades móveis autónomas
Doutoramento em Engenharia ElectrotécnicaInterest on using teams of mobile robots has been growing, due to their
potential to cooperate for diverse purposes, such as rescue, de-mining,
surveillance or even games such as robotic soccer. These applications require
a real-time middleware and wireless communication protocol that can support
an efficient and timely fusion of the perception data from different robots as well
as the development of coordinated behaviours. Coordinating several
autonomous robots towards achieving a common goal is currently a topic of
high interest, which can be found in many application domains. Despite these
different application domains, the technical problem of building an infrastructure
to support the integration of the distributed perception and subsequent
coordinated action is similar. This problem becomes tougher with stronger
system dynamics, e.g., when the robots move faster or interact with fast
objects, leading to tighter real-time constraints.
This thesis work addressed computing architectures and wireless
communication protocols to support efficient information sharing and
coordination strategies taking into account the real-time nature of robot
activities. The thesis makes two main claims. Firstly, we claim that despite the
use of a wireless communication protocol that includes arbitration mechanisms,
the self-organization of the team communications in a dynamic round that also
accounts for variable team membership, effectively reduces collisions within the
team, independently of its current composition, significantly improving the
quality of the communications. We will validate this claim in terms of packet
losses and communication latency. We show how such self-organization of the
communications can be achieved in an efficient way with the Reconfigurable
and Adaptive TDMA protocol.
Secondly, we claim that the development of distributed perception, cooperation
and coordinated action for teams of mobile robots can be simplified by using a
shared memory middleware that replicates in each cooperating robot all
necessary remote data, the Real-Time Database (RTDB) middleware. These
remote data copies, which are updated in the background by the selforganizing
communications protocol, are extended with age information
automatically computed by the middleware and are locally accessible through
fast primitives. We validate our claim showing a parsimonious use of the
communication medium, improved timing information with respect to the shared
data and the simplicity of use and effectiveness of the proposed middleware
shown in several use cases, reinforced with a reasonable impact in the Middle
Size League of RoboCup.O interesse na utilização de equipas multi-robô tem vindo a crescer, devido ao
seu potencial para cooperarem na resolução de vários problemas, tais como
salvamento, desminagem, vigilância e até futebol robótico. Estas aplicações
requerem uma infraestrutura de comunicação sem fios, em tempo real,
suportando a fusão eficiente e atempada dos dados sensoriais de diferentes
robôs bem como o desenvolvimento de comportamentos coordenados. A
coordenação de vários robôs autónomos com vista a um dado objectivo é
actualmente um tópico que suscita grande interesse, e que pode ser
encontrado em muitos domínios de aplicação. Apesar das diferenças entre
domínios de aplicação, o problema técnico de construir uma infraestrutura para
suportar a integração da percepção distribuída e das acções coordenadas é
similar. O problema torna-se mais difícil à medida que o dinamismo dos robôs
se acentua, por exemplo, no caso de se moverem mais rápido, ou de
interagirem com objectos que se movimentam rapidamente, dando origem a
restrições de tempo-real mais apertadas.
Este trabalho centrou-se no desenvolvimento de arquitecturas computacionais
e protocolos de comunicação sem fios para suporte à partilha de informação e
à realização de acções coordenadas, levando em consideração as restrições
de tempo-real. A tese apresenta duas afirmações principais. Em primeiro
lugar, apesar do uso de um protocolo de comunicação sem fios que inclui
mecanismos de arbitragem, a auto-organização das comunicações reduz as
colisões na equipa, independentemente da sua composição em cada
momento. Esta afirmação é validada em termos de perda de pacotes e latência
da comunicação. Mostra-se também como a auto-organização das
comunicações pode ser atingida através da utilização de um protocolo TDMA
reconfigurável e adaptável sem sincronização de relógio.
A segunda afirmação propõe a utilização de um sistema de memória
partilhada, com replicação nos diferentes robôs, para suportar o
desenvolvimento de mecanismos de percepção distribuída, fusão sensorial,
cooperação e coordenação numa equipa de robôs. O sistema concreto que foi
desenvolvido é designado como Base de Dados de Tempo Real (RTDB). Os
dados remotos, que são actualizados de forma transparente pelo sistema de
comunicações auto-organizado, são estendidos com a respectiva idade e são
disponibilizados localmente a cada robô através de primitivas de acesso
eficientes. A RTDB facilita a utilização parcimoniosa da rede e bem como a
manutenção de informação temporal rigorosa. A simplicidade da integração da
RTDB para diferentes aplicações permitiu a sua efectiva utilização em
diferentes projectos, nomeadamente no âmbito do RoboCup
Noise exposure and vocal behaviour of baleen whales off the Azores
Tese de Doutoramento, Ciências do Mar (Ecologia Marinha), 31 de março de 2022, Universidade dos Açores.As baleias comum (Balaenoptera physalus), azul (B. musculus) e sardinheira (B. borealis) produzem vocalizações de baixa frequência e grande amplitude que podem ser repetidas num padrão regular, formando canções, ou produzidas de forma irregular, como vocalizações individuais ou em grupo. As canções são produzidas por machos, sobretudo na época de acasalamento, e acredita-se serem usadas como exibições reprodutivas, enquanto as vocalizações irregulares podem ter varias funções associadas a contextos sociais e de alimentação. As técnicas de acústica passiva permitem monitorizar áreas remotas por longos períodos de tempo, possibilitando o estudo dos padrões temporais e espaciais das vocalizações, assim com as suas funções, e elucidando aspetos essenciais da biologia e ecologia destas espécies com elevada mobilidade e elusivas, que de outra maneira seria difícil ou impossível obter. O objetivo principal desta tese é investigar o comportamento vocal das baleias comum, azul e sardinheira (com um foco especial na baleia comum), para adquirir um melhor conhecimento da sua ecologia e comportamento durante a migração, a fase menos conhecida do seu ciclo de vida. Este estudo também investiga os níveis de ruído produzido pelo tráfego marinho em relação ao comportamento vocal destas três espécies, e discute as implicações potenciais para o seu comportamento migratório.
[…].ABSTRACT: Fin (Balaenoptera physalus), blue (B. musculus) and sei whales (B. borealis) produce very low frequency and high amplitude vocalisations that can be regularly repeated as songs or irregularly produced as single or grouped calls. While songs are produced by males, peak during the mating season and are believed to act as reproductive displays, calls may have multiple functions associated to feeding and social contexts. By using passive acoustic techniques, that allow long-term continuous monitoring of remote areas, the study of temporal and spatial patterns of vocalisations as well as their functions can elucidate important aspects of the biology and ecology of these highly mobile and elusive species that would otherwise be difficult or impossible to obtain. The main goal of this dissertation is to investigate the vocal behaviour of fin, blue and sei whales (with a special focus on the fin whale), to contribute to a better understanding of their ecology and behaviour during migration, the least known phase of their annual life cycle. This study also investigates shipping noise levels in relation to the vocal behaviour of these three species and discusses potential implications for their migratory behaviour.
[…].This thesis was supported by the doctoral grant M3.1.a/F/028/2015 from the Fundo Regional da Ciência e Tecnologia (FRCT). The research stay was funded by the grant FC/FLAD/FMF/CND1/2017/002 of the “Programa Fundo de Mobilidade FLAD-UAc - Crossing the Atlantic”. And co-funded by the following research projects and institutions: TRACE (PTDC/MAR/74071/2006) MAPCET (M2.1.2/F/012/2011) AWARENESS (PTDC/BIA-BMA/30514/2017) MOVE-ON (IF/00943/2013/CP1199/CT0001)
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