Adriano Carvalho

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Building cooperatively 3-D maps of unknown environments is one of the application fields of multi-robot systems. This article introduces a distributed architecture, within a probabilistic framework for vision-based 3-D mapping, whereby each robot is committed to cooperate with other robots through information sharing. An entropy-based measure of information(More)
This thesis addresses the problem of how to share efficiently information within a robotic system comprised of several mobile robots, which are programmed to exhibit cooperative behavior in the context of building volumetric maps of unknown environments. More specifically, it addresses the following issues: representing a probabilistic map and improving it(More)
This article presents an innovative probabilistic approach for building volumetric maps of unknown environments with autonomous mobile robots, which is based on information theory. Each mobile robot uses an entropy gradient-based exploration strategy, with the aim of maximizing information gain when building and improving a 3D map upon measurements yielded(More)
The paper focus dependability modelling and evaluation of fieldbus networks in the presence of permanent faults. Several architectures are analysed, considering different operating modes, topologies and fault types. Two measures of dependability are evaluated: reliability and asymptotic unavailability. The aim is to compare these various design solutions,(More)
Fieldbus networks have been assuming a high acceptance in the industrial environment, replacing the old centralized control architectures. Due to time critical nature of the tasks involved in these environments, the fulfillment of dependability attributes is usually required. Therefore the dependability is an important parameter on system design, which(More)
One of the application fields of multirobot systems is cooperative mapping of an unknown environment. In this article, the problem of mapping an unknown 3-D environment is formulated through a probabilistic model based on information theory. Besides describing how such a map is updated upon new measurements, we use the map to estimate a spatial field of(More)
In this article we propose a measure of information utility that can be used to enable more effective cooperation in multi-robot systems (MRS). After giving some background in the area and making some references to the state of the art, we present an observation model for a MRS, based on which we devise a formal method to assess the information utility. The(More)
Building cooperatively 3-D maps of unknown environments is one of the application fields of multi-robot systems. This article focuses on the exploration problem with multiple robots, starting upon a previously proposed successful distributed architecture. An entropy gradient-based algorithm is used to select exploration viewpoints in the frontier between(More)