34 research outputs found
Decision making for a delivery robot through a fuzzy system
One of the main objectives of robotic researches has been the use of autonomous agents to make ”mundane” tasks. A typical task common in literature is fetching a document from an initial point local and deliver to a specified destination. In this work, a fuzzy system has been developed to manage a number of requests that a robot has to deliver, which are requested in real time. This system uses a set of fuzzy rules to define the priority of each request based on conditions such as the time limit to take the document from its source or the score acquired from a successful delivery. A modification of A* algorithm to plan paths and the potential field technique to manage navigation are used to guide the robot in the environment. Three different sets of fuzzy rules have been tested in order to compare their results with the known algorithm, first-in first-out, to attend the requests. The Player/Stage simulator has been used to make the tests. The results show that such approach is effective, obtaining better results on criteria which have been considered of greater importance for each set of rules
Interface for communication between robotic and cognitive systems through the use of a cognitive ontology
The demand for socially interactive robots has increased annually. In particular, service robots have invaded homes and worked directly with humans who, in general, are not familiar with such devices. Their acceptance is conditioned to the evolution of research in the area of human-robot interaction. This paper contributes towards this acceptance process presenting an ontology that accelerates the implementation of cognitive systems in robots and enables the reproduction of experiments associated with cognitive models and comparison among different implementations. The specific objective is the definition of an ontology that provides a protocol for communication between cognitive and robot part systems.FAPESP (2013/26453-1
Indefinite numerical range of 3×3 matrices
Copyright © 2009, Springer Netherlands.The point equation of the associated curve of the indefinite numerical range is derived, following Fiedler’s approach for definite inner product spaces. The classification of the associated curve is presented in the 3 × 3 indefinite case, using Newton’s classification of cubic curves. Illustrative examples of all the different possibilities are given. The results obtained extend to Krein spaces results of Kippenhahn on the classical numerical range
A mobile virtual character with emotion-aware strategies for human-robot interaction
Emotions may play an important role in human-robot interaction, especially with social robots. Although the emotion recognition problem has been massively studied, few research is aimed at investigating interaction strategies produced as response to inferred emotional states. The work described in this paper consists on conceiving and evaluating a dynamic in which, according to the user emotional state inferred through facial expressions analysis, two distinct interaction strategies are associated to a virtual character. An Android app, whose development is in progress, aggregates the user interface and interactive features. We have performed user experiments to evaluate whether the proposed dynamic is effective in producing more natural and empathic interaction.FAPESP (São Paulo State Research Support Foundation) (grant 2014/16862-4
Development of distributed control architecture for multi-robot systems
The execution of complex tasks by teams of robots has been widely investigated in the last decades, since many operations are too risky or difficult to be performed by humans or by a single robot. The complexity and variety of applications of mobile robotics make the coordination of teams a big problem, as several topologies of control systems, from simple single processes to large networks with distributed elements that are capable of switching function, may be necessary. Although simple solutions exist, more efficient approaches use distributed communication architectures and components abstraction layers. Available proposals provide many components and interfaces, complicating their understanding and operation. This paper presents a generic control architecture that provides the developer with a small amount of elements implemented safely and on high-performance libraries. The simplicity and modularity of the proposal allow implementation of features such as control of heterogeneous robots, data source and command destination transparency and platform and language independence. The ability to support with reliability, transparency and ease the development of various scenarios of autonomous mobile robotics make the proposed architecture a powerful and valuable tool in the design and operation of these systems.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Centro de Tecnologia da Informação Renato Arche
An approach for coordinating of the cooperative mapping in a self-adaptive formation system based on a modification of the ant colony algorithm
In this work, an approach for cooperative and distributed mapping in a self-adaptive formation system based on a modified version of the ant colony optimization algorithm is proposed. The strategy is distributed, decentralized, real time and it is applied to tasks in which formation characteristic is an essential requirement. The coordination system’s design is inspired by the biological mechanisms that define a social organization in collective systems, specifically, the ant colony system. Voronoi tessalation and Delaunay triangulation techniques are used to model the formation strategy. The approach is adaptable for scenarios with suffer changes in the structure of the environment. The performance of the system is evaluated using a simulator. Simulation results show that the cooperative mapping is efficient, the trials are performed considering an indoor environment. Besides results show that the proposed formation approach is able to rearrange spatially the robots as they navigate, changing the relative robot distances according to the spatial environment restrictions.FAPESP (Grant #2010/07955-8)CNP
An object-based visual selection model combining physical features and memory
In this paper, a new visual selection model is proposed, which combines both early visual features and object-based visual selection modulations. This model integrates three main mechanisms. The first is responsible for the segmentation of the scene allowing the identification of objects. In the second one, the average of saliency of each object is calculated for each feature considered in this work, which provides the modulation of the visual attention for one or more features. Finally, the third mechanism is responsible for building the object-saliency map, which highlights the salient objects in the scene. It will be shown that top-down modulation can overcome bottom-up saliency by selecting a known object instead of the most salient (bottom-up) and is even clear in the absence of any bottom-up clue. Several experiments with synthetic and real images are conducted and the obtained results demonstrate the effectiveness of the proposed approach for visual attention
A visual attention approach for the tracking of vehicles through UAV
Thermal imaging analysis is an important tool in the study of wildlife animals. The segmentation of thermal images has not extensively explored by the Ecology and Biology communities. In this paper we propose a new approach for segmenting thermal images using the SLIC superpixel algorithm and connected component labeling. Experiments were performed on images taken over the behaviour activity of four mammal species. The results show that our approach has a great potential for partioning animals and background.FAPESP (processo 2012/14725-4)CNP
Análise de uma estratégia de coordenação bio-inspirada de múltiplos robôs para a tarefa de vigilância em ambientes desconhecidos
Uma estratégia distribuída de coordenação modelada de acordo com uma versão modificada do algoritmo que simula o comportamento de formigas guia robôs móveis para região não exploradas e regiões não recentemente exploradas. Em pesquisa anterior, a aplicação da estratégia confirmou que comportamentos de exploração e vigilância emergem do comportamento individual do agente. A estratégia é capaz de adaptar o sistema proposto para situações em que o número de robôs ou a estrutura do ambiente mudam. Nesta pesquisa, uma variação paramétrica da estratégia é empregada com base nos fenômenos de evaporação e propagação do feromônio. Resultados experimentais demonstram que diferentes configurações do fenômeno afetam o comportamento de exploração e vigilância. Os resultados mostram a eficiência da estratégia para realizar tarefas cooperativas.FAPESPCNPqCAPE
Species pool structure determines the level of generalism of island parasitoid faunas
Copyright © 2011 Blackwell Publishing Ltd.AIM To examine whether island parasitoid faunas are biased towards generalists when compared with the mainland and their species pool, and to evaluate the effects of climate, island characteristics and regional factors on the relative proportions of idiobionts (i.e. generalists) and koinobionts (i.e. specialists) of two parasitic wasp families, Braconidae and Ichneumonidae. LOCATION Seventy-three archipelagos distributed world-wide. METHODS We used data on the distribution and biology obtained from a digital catalogue and several literature sources. We related level of generalism, measured as the ratio between the number of idiobiont and koinobiont species, to climatic, physiographic and regional factors using generalized linear models. We compared models by means of Akaike weighting, and evaluated the spatial structure of their residuals. We used partial regressions to determine whether the final models account for all latitudinal structure in the level of generalism. RESULTS Islands host comparatively more idiobionts than continental areas. Although there is a latitudinal gradient in the level of generalism of island faunas correlating with both environmental factors and island characteristics, the most important determinant of island community structure is their source pool. This effect is stronger for ichneumonids, where generalism is higher in the Indomalayan region, arguably due to the higher diversity of endophytic hosts in its large rain forests. MAIN CONCLUSIONS The level of generalism of island parasitoid faunas is largely constrained by regional factors, namely by the structure of the species pool, which emphasizes the importance of including regional processes in our understanding of the functioning of ecological communities. The fact that generalist species are more predominant in islands with a large cover of rain forests pinpoints the importance of the indirect effects of ecological requirements on community structure, highlighting the complex nature of geographical gradients of diversity