| 1. |
- Andersson, Thord, 1972-, et al.
(author)
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Fuzzy matching of visual cues in an unmanned airborne vehicle
- 1999
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Reports (other academic/artistic)abstract
- Computer vision systems used in autonomous mobile vehicles are typically linked to higher-level deliberation processes. One important aspect of this link is how to connect, or anchor, the symbols used at the higher level to the objects in the vision system that these symbols refer to. Anchoring is complicated by the fact that the vision data are inherently affected by uncertainty. We propose an anchoring technique that uses fuzzy sets to represent the uncertainty in the perceptual data. We show examples where this technique allows a deliberative system to reason about the objects (cars) detected by a vision system embarked in an unmanned helicopter, in the framework of the Witas project.
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| 2. |
- Boldrin, Luca, et al.
(author)
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A modal logic for fusing partial belief of multiple reasoners
- 1999
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In: Journal of logic and computation (Print). - : Oxford University Press (OUP). - 0955-792X .- 1465-363X. ; 9:1, s. 81-103
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Journal article (peer-reviewed)abstract
- We present PLn, a multi-agent epistemic logic in which each agent can perform uncertain (possibilistic) reasoning. The original feature of this logic is the presence of a distributed belief operator, with the purpose of merging the belief of different agents. Unlike the corresponding operator in the categorical (non-uncertain) case, our distributed belief operator accumulates support for the same fact coming from different agents. This means that opinions shared by different agents can be combined into a stronger distributed belief. This feature is useful in problems like pooling expert opinions and combining information from multiple unreliable sources. We provide a possible worlds semantics and an axiomatic calculus for our logic, and prove soundness, completeness and decidability results. We hint at some possible applications of PLn in the conclusions
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| 3. |
- Coradeschi, Silvia, et al.
(author)
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Anchoring symbolic object descriptions to sensor data. Problem statement
- 1999
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Reports (other academic/artistic)abstract
- Every intelligent agent embedded in physical environments needs the ability to connect, or anchor, the symbols used to perform abstract reasoning to the physical entities which these symbols refer to. However, there appears to be no general definition of this ability, nor of the principles that characterize it, in the context of autonomous embedded systems. In this paper, we do the first steps toward a definition of the concept of anchoring and its functionalities. We also outline a few difficulties of anchoring: the need to deal with indexical and objective references, definite and indefinite identifiers; the temporary impossibility to percept physical entities; and the need to rely on sensor data which is inherently affected by uncertainty and ambiguities. We illustrate the use of anchoring in two domains: an autonomous airborne vehicle for traffic surveillance, and a mobile ground vehicle performing navigation tasks.
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| 4. |
- Coradeschi, Silvia, et al.
(author)
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Anchoring symbols to vision data by fuzzy logic
- 1999
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In: Symbolic and quantitative approaches to reasoning and uncertainty. - Berlin/Heidelberg : Springer Berlin/Heidelberg. - 354066131X ; , s. 104-115
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Conference paper (peer-reviewed)abstract
- Intelligent agents embedded in physical environments need the ability to connect, or anchor, the symbols used to perform abstract reasoning to the physical entities which these symbols refer to. Anchoring must rely on perceptual data which is inherently affected by uncertainty. We propose an anchoring technique based on the use of fuzzy sets to represent uncertainty, and of degree of subset-hood to compute the partial match between signatures of objects. We show examples where we use this technique to allow a deliberative system to reason about the objects (cars) observed by a vision system embarked in an unmanned helicopter, in the framework of the WITAS project.
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| 5. |
- Gasós, Jorge, et al.
(author)
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Integrating fuzzy geometric maps and topological maps for robot navigation
- 1999
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Conference paper (peer-reviewed)abstract
- Autonomous mobile robots need to use spatial information about the environment in order to effectively plan and execute navigation tasks. This information can be represented at different level of abstractions, ranging from detailed geometric maps to coarse topological maps. Each level is adequate for some sub-tasks, but not for others. In this paper, we propose to use hybrid maps, patchworks of local metric maps connected into a topological network. Our hybrid maps are peculiar in that they use fuzzy sets to represent the uncertainty that affects metric information. We show how a robot can build hybrid maps from sensor data, and how it can use them in autonomous indoor navigation. We also report experiments performed on a real mobile robot that demonstrate the robustness of our approach with respect to inaccuracies in the map and noise in the sensor data.
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| 6. |
- Gasós, Jorge, et al.
(author)
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Using fuzzy sets to represent uncertain spatial knowledge in autonomous robots
- 1999
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In: Spatial Cognition and Computation. - 1387-5868 .- 1573-9252. ; 1:3, s. 205-226
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Journal article (peer-reviewed)abstract
- Autonomous mobile robots need the capability to reason from and about spatial knowledge. Due to limitations in the prior information and in the perceptual apparatus, this knowledge is inevitably affected by uncertainty. In this paper, we discuss some techniques employed in the field of autonomous robotics to represent and use uncertain spatial knowledge. We focus on techniques which use fuzzy sets to account for the different facets of uncertainty involved in spatial knowledge. These facets include the false measurements induced by bad observation conditions; the inherent noise in odometric position estimation; and the vagueness introduced by the use of linguistic descriptions. To make the discussion more concrete, we illustrate some of these techniques showing samples from our work on mobile robots.
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| 7. |
- Parsons, Simon, et al.
(author)
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Robots with the best of intentions
- 1999
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In: Artificial intelligence today. - Berlin : Springer. - 3540664289 ; , s. 329-338
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Book chapter (other academic/artistic)abstract
- Intelligent mobile robots need the ability to integrate robust navigation facilities with higher level reasoning. This paper is an attempt at combining results and techniques from the areas of robot navigation and of intelligent agency. We propose to integrate an existing navigation system based on fuzzy logic with a deliberator based on the so-called BDI model. We discuss some of the subtleties involved in this integration, and illustrate it on a simulated example. Experiments on a real mobile robot are under way
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| 8. |
- Saffiotti, Alessandro
(author)
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Handling uncertainty in control of autonomous robots
- 1999
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In: Artificial intelligence today. - Berlin : Springer Berlin/Heidelberg. - 3540664289 ; , s. 381-407
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Book chapter (peer-reviewed)abstract
- Autonomous robots need the ability to move purposefully and without human intervention in real-world environments that have not been specifically engineered for them. These environments are characterized by the pervasive presence of uncertainty: the need to cope with this uncertainty constitutes a major challenge for autonomous robots. In this note, we discuss this challenge, and present some specific solutions based on our experience on the use of fuzzy logic in mobile robots. We focus on three issues: how to realize robust motion control; how to flexibly execute navigation plans; and how to approximately estimate the robot's location.
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| 9. |
- Saffiotti, Alessandro, et al.
(author)
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Using fuzzy logic for mobile robot control
- 1999
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In: Practical applications of fuzzy technologies. - : Kluwer Academic, MA. - 0792386280 ; , s. 185-205
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Book chapter (other academic/artistic)abstract
- The development of techniques for autonomous operation in real-world, unstructured environments constitutes one of the major trends in the current research on mobile robotics. In spite of recent advances, a number of fundamental difficulties remain. In this chapter, we discuss how fuzzy logic techniques can be used to address some of these difficulties. To illustrate the discussion, we describe the fuzzy-logic solutions developed on Flakey, the mobile robot of SRI International
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| 10. |
- Wide, Peter, et al.
(author)
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Environmental exploration : an autonomous sensory systems approach
- 1999
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In: IEEE Instrumentation & Measurement Magazine. - : Institute of Electrical and Electronics Engineers (IEEE). - 1094-6969 .- 1941-0123. ; 2:3, s. 28-32
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Journal article (peer-reviewed)abstract
- The purpose of this article is to demonstrate new paradigms in the analysis and design of virtual instrumentation in autonomous sensor systems. By autonomous sensor systems we mean mobile as well as immobile systems that employ a vast array of sensors to analyze or influence dynamic and uncertain external changes. These systems must perform operations in real time, in both expected and unexpected situations, using only limited human intervention. An autonomous sensor system can be used to collect data about a complex and dynamic environment, to perform interpretation and fusion of this data, and to present the resulting information to a human operator in a synthetic form that highlights features of interest of the environment. The system can then be regarded as a virtual instrument. A useful form to organize and present this information is a virtual spatial map-a representation of the environment in which colored geometric figures are placed to indicate that a given feature (or event) has been detected at that location. We illustrate our approach of building virtual instruments by presenting a case study of semi-autonomous remote environmental exploration. A mobile platform gathers information about a remote environment using multi-modal sensor data collection, information processing, and data fusion at different levels of abstraction and resolution. The result of the exploration is a fused virtual map that contains the important features of the environment
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