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Advanced Mobile Robots, 1999. (Eurobot '99) 1999 Third European Workshop on

Date 6-8 Sept. 1999

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  • 1999 Third European Workshop on Advanced Mobile Robots (Eurobot'99). Proceedings (Cat. No.99EX355)

    Publication Year: 1999
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    Freely Available from IEEE
  • Table of contents

    Publication Year: 1999 , Page(s): 0_6 - 0_8
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    Freely Available from IEEE
  • A behavior-based architecture for teaching more than reactive behaviors to mobile robots

    Publication Year: 1999 , Page(s): 203 - 210
    Cited by:  Papers (7)
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    The article gives an overview of learning aspects regarding behavior based control architectures for autonomous mobile robots. We propose a common, modularized architecture, which is particularly suited for learning experiments. The main focus lies in “Learning from Demonstration” in a spatial domain, which means teaching motor behaviors by humans or other robots. First results applying RBF approximation, growing neural cell structures and probabilistic models for progress estimation are presented View full abstract»

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  • Localization in changing environments by matching laser range scans

    Publication Year: 1999 , Page(s): 169 - 176
    Cited by:  Papers (3)  |  Patents (1)
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    We present a novel scan matching algorithm, IDC-S, Iterative Dual Correspondence-Sector, that matches range scans. The algorithm is based on the known Iterative Dual Correspondence, IDC, algorithm which has shown good performance in real environments. The improvement is that IDC-S is able to deal with relatively large changes in the environment. It divides the scan in several sectors, detects and removes those sectors that are changed and matches the scans only using unchanged sectors. IDC-S and other variants of IDC are extensively simulated and evaluated. The simulations show that IDC-S is very robust and can locate in many different kind of environments. We also show that it is possible to effectively combine the existing IDC algorithms with IDC-S, thus obtaining an algorithm that performs very well both in rectilinear as well as nonrectilinear environments, even when changed as much as 65% View full abstract»

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  • Motion control of a snakelike robot

    Publication Year: 1999 , Page(s): 1 - 8
    Cited by:  Papers (1)
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    Sliding, creeping and climbing are easy for real snakes but not for robots. We attempt to build a robot which can move as similar to real snakes as possible. The first version of our robot, GMD-Snake, was constructed in 1996. It was able to creep on a plain surface, to cross obstacles, and to follow a light source. A re-design was then started to enhance and improve the snake's abilities. An important part of the work is to build a simulation tool, which enables the designer to generate efficient motion and can be used as a basis for motion control. The modeling and simulation tool MOSES was developed for planar motion, where the wheels drive the articulated body and coordinated bending of several active joints causing spatial motion. The simulation is based on the fact that the real system will move in such a way that only a minimum of energy is required View full abstract»

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  • Attention as selection-for-action: a scheme for active perception

    Publication Year: 1999 , Page(s): 113 - 119
    Cited by:  Papers (1)  |  Patents (1)
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    Proposes three principles for attentional control of actions in autonomous robots. (1) Attention-as-action suggests that attentional shifts and the selection of the focus of attention should be seen as actions rather than as a purely sensory process. (2) Selection-for-action suggests that actions should be implicitly controlled by the current focus of attention. (3) Deictic reference is a method of referring to an external object without explicitly representing all of its properties. The three principles are illustrated in two examples: first for a mobile robot, and second for a visually controlled manipulator. In the second example, we also report two learning experiments where a robot picks out the correct focus of attention for a task based on reinforcement learning View full abstract»

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  • Strategies for navigation of robot swarms to be used in landmines detection

    Publication Year: 1999 , Page(s): 211 - 218
    Cited by:  Papers (2)
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    The paper presents a novel approach to the detection of anti-personnel landmines that uses teams of cooperating robots. Following hints that originate both from classical robotics and from biology, we aim to define a set of search strategies suitable for use in an obstacle-cluttered, two-dimensional space. The paper presents the guidelines of the project, the search strategies that were developed, and a description of a simulator that was designed and implemented to test them. Brief reviews of the available techniques, of the sensor technologies, and of the current uses of robotic devices in humanitarian demining are also included View full abstract»

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  • Improving robustness and precision in mobile robot localization by using laser range finding and monocular vision

    Publication Year: 1999 , Page(s): 177 - 185
    Cited by:  Papers (9)
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    The paper discusses mobile robot localization by means of geometric features from a laser range finder and a CCD camera. The features are line segments from the laser scanner and vertical edges from the camera. Emphasis is put on sensor models with a strong physical basis. For both sensors, uncertainties in the calibration and measurement process are adequately modeled and propagated through the feature extractors. This yields observations with their first order covariance estimates which are passed to an extended Kalman filter for fusion and position estimation. Experiments on a real platform show that, opposed to the use of the laser range finder only, the multisensor setup allows the uncertainty to stay bounded in difficult localization situations like long corridors, and contributes to an important reduction of uncertainty, particularly in the orientation. The experiments further demonstrate the applicability of such a multisensor localization system in real time on a fully autonomous robot View full abstract»

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  • Sonar interpretation learned from laser data

    Publication Year: 1999 , Page(s): 121 - 126
    Cited by:  Papers (1)
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    Sensor interpretation in mobile robots often involves an inverse sensor model, which generates hypotheses on specific aspects of the robot's environment based on current sensor data. Building inverse sensor models for sonar sensor assemblies is a particularly difficult problem that has received much attention in the past few years. A common solution is to train neural networks using supervised learning. However, large amounts of training data are typically needed, consisting, for example, of scans of recorded sonar data which are labeled with manually constructed teacher maps. Obtaining these training data is an error-prone and time-consuming process. We suggest that it can be avoided if an additional sensor, like a laser scanner, is also available which can act as the feeding signal. We have successfully trained inverse sensor models for sonar interpretation using laser scan data. In this paper, we describe the procedure we used and the results we obtained View full abstract»

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  • Multi-agent control system for the symmetric body robot

    Publication Year: 1999 , Page(s): 25 - 32
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    This paper describes a multi-agent control system for autonomous robots, especially, for the symmetric body robot (SBR). The SBR has several interesting characteristics: it has five symmetrical arms, each of them is driven twenty SMA-coils; and each of the five arms has an independent control board on the root of them. The SBR is completely symmetrical as far as detailed components. It has a high degree of freedom for changing its own body. For controlling the robot behaviors, we consider not only to create suitable action selection mechanisms, but also to study its physical body and the effect of changing its body shape. This paper shows some experiments of the autonomous robot that has the ability to change its own body shape actively View full abstract»

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  • Hierarchical decision-theoretic planning for autonomous robotic surveillance

    Publication Year: 1999 , Page(s): 219 - 226
    Cited by:  Papers (3)
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    Surveillance as a first step towards automating the planning of the movement of an autonomous surveillance robot. We extend a previous proposal (N. Massios and F. Voorbraak, 1998), by including some heuristics based on an abstract representation of the environment. We show, using a concrete example, how these heuristics allow computationally feasible, finite look-ahead versions of the decision-theoretic strategy to escape local minima, and to better approximate globally optimal solutions View full abstract»

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  • 20 years of progress in mobile robotics: a historical perspective

    Publication Year: 1999 , Page(s): 159
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    First Page of the Article
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  • A conceptual representation of the actions of an autonomous robot

    Publication Year: 1999 , Page(s): 97 - 104
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    An autonomous robot involved in long and complex missions should be able to generate, update and process its own plans of action. In this perspective, it is not plausible for the meaning of the representations used by the robot to be given from outside the system itself. Rather, the meaning of internal symbols must be firmly anchored to the world through the perceptual abilities and the overall activities of the robot. According to these premises, we present an approach to action representation that is based on a “conceptual” level of representation, acting as an intermediate level between the symbols and data coming from the sensors. Symbolic representations are interpreted by mapping them onto the conceptual level through a mapping mechanism based on artificial neural networks. Examples of the proposed framework are reported, based on experiments performed on a RWI-B12 autonomous robot View full abstract»

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  • Template-based state estimation of dynamic objects

    Publication Year: 1999 , Page(s): 33 - 39
    Cited by:  Papers (1)
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    In order to plan their missions and to carry them out successfully, mobile robots operating in changing environments need to keep track of the state of objects. The perception of changes in the environment and the integration of changes into the robot's world model is therefore an important problem in mobile robotics. Most of today's systems plan their missions based on static models, thus limiting their applicability. We introduce a method to maintain environment models by estimating the state of changing objects, e.g. their current position and configuration, from sensor data. Unlike other methods, which acquire and maintain sub-symbolic environment models, our method automatically maintains a symbolic CAD model. The method proposed is a Bayesian state estimator which computes the maximum likelihood estimate of the state of a dynamic object by matching templates of the object against proximity information obtained by the robot. The algorithm employs Monte Carlo Markov localization to determine the robot's position in its environment. The localization provides a probability density of the robot's position, and matching takes this density into account, to achieve robust state estimates even while the robot is moving. Experiments carried out on a mobile robot in our office environment illustrate the capabilities of our approach with respect to the robustness of the state estimates View full abstract»

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  • Guidance principle and robustness issues for a biologically-inspired visual homing

    Publication Year: 1999 , Page(s): 143 - 150
    Cited by:  Papers (3)
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    Analyses the guidance principle and the robustness features of a biologically-inspired visual homing algorithm for autonomous robots. The homing strategy uses colour images and is based on an affine matching model whose parameters are used to estimate real navigation displacement in the environment. The guidance principle of the visual homing is proven to be a visual potential function with an equilibrium point located at the goal position. The presence of a potential function means that classical control-theory principles based on the Lyapunov functions can be applied to assess the robustness of the navigation strategy View full abstract»

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  • Studying robot social cognition within a developmental psychology framework

    Publication Year: 1999 , Page(s): 187 - 194
    Cited by:  Papers (3)
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    The paper discusses two prominent theories of cognitive development and relates them to experiments in social robotics. The main difference between these theories lies in the different views on the relationship between a child and its social environment: a) the child as a solitary thinker (Piaget) and b) the child in society (Vygotsky). We discuss the implications this has on the design of socially intelligent agents, focusing on robotic agents. We argue that the framework proposed by Vygotsky provides a promising research direction in autonomous agents. We give examples of implementations in the area of social robotics which support our theoretical considerations. More specifically, we demonstrate how a teacher-learner setup can be used to teach a robot a proto-language. The same control architecture is also used for a humanoid doll robot which can interact with a human by imitation. Another experiment addresses dynamic coupling of movements between a human and a mobile robot. Here, emergent robot-human interaction dynamics are influenced by the temporal coordination between the robot's and the human's movements View full abstract»

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  • Acceleration compensation using a Stewart platform on a mobile robot

    Publication Year: 1999 , Page(s): 17 - 24
    Cited by:  Papers (2)
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    Transporting an object on a mobile platform always transfers accelerations to this object. In many cases this is undesirable, so a compensation would be helpful. There are passive systems, but they can only react and have no other use like manipulating. This paper presents a solution for both compensation of accelerations and precise and powerful manipulation. In order to achieve a compensation a Stewart platform is mounted on top of a mobile robot. Usually a Stewart platform is used to generate accelerations. In this application the acceleration vector of the robot is inverted and sent to the filter, which performs the platform motion depending on the robot movement. This filter handles all six degrees of freedom, so every movement can be taken into account, if it is determined by acceleration or inclination sensors. Furthermore, this combination is also a very precise docking system, since the Stewart platform can easily correct the uncertainty in the robot position View full abstract»

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  • Development of a visual object localization module for mobile robots

    Publication Year: 1999 , Page(s): 65 - 72
    Cited by:  Papers (2)  |  Patents (51)
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    Reports preliminary results from the design and implementation of a visual object localization module for mobile robots. The module takes an object-based approach to visual processing and relies on a preprocessing step that segments objects from the image. By tracking the size and the eccentricity of the objects in the image while the robot is moving, the visual object localization module can determine the position of objects relative to the robot using the displacement obtained from its odometry. In localizing the objects, the module is designed to combine the results of two different techniques. The visual looming technique measures the distance to an object using the change in the size of the object on the image plane. This technique is to be complemented by a variant of the triangulation technique that can locate an object using the eccentricity of the object when viewed from two different points. The module-with the preprocessing algorithm-is being implemented to run in real-time on a mobile robot. Evaluation of the visual localization module is being done in an integrated system introduced in the article. The integrated system creates an environment for real-time evaluation of the module as well as other mapping and navigation algorithms for mobile robots View full abstract»

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  • Interfacing different layers of a multilayer architecture for sensorimotor systems using the object-oriented framework SMARTSOFT

    Publication Year: 1999 , Page(s): 195 - 202
    Cited by:  Papers (5)
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    Advanced mobile robots have to cope with many different situations and have to fulfil their tasks even in dynamic environments. Furthermore, there is an increasing demand that those systems perform not only a single task but show a whole set of different capabilities. This includes the concurrent and interruptable execution of several tasks. Reliably performing different tasks over long periods of time not only requires advanced basic skills, but also an appropriate robot control architecture. This includes, e.g., mechanisms to coordinate the execution of competing tasks. We present the architecture used on our B21 demonstrator of the SFB 527. A special emphasis is laid on aspects of our supporting software framework, SMARTSOFT, and the implemented set of skills View full abstract»

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  • Learning to acquire and select useful landmarks for route following

    Publication Year: 1999 , Page(s): 161 - 168
    Cited by:  Papers (1)  |  Patents (2)
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    The paper describes a prototypical system for optimal landmark acquisition and selection. Our landmark-learning approach does not require any type of environment model to be supplied to the robot in advance, and represents a step towards robots interacting with real environments. The approach is fitted and tested for the TMGA system (P. Zingaretti et al., 1998), which the authors developed for landmark tracking by adaptive, stereo template matching. Two complementary strategies, properly managed, are followed to construct a suitable subset of landmarks: the selection of the more discriminant landmarks and the selection of the landmarks that are more invariant in a neighbourhood. The robustness of the TMGA system in analysing the discriminant power of each landmark and the analysis of the disparity map and of the spatial activity maps of the stereo images are used for identifying discriminant and invariant landmarks. The experimental results show that the number of matching failures, and consequent landmark changes during the following of a route is comparable with (not much greater than) those obtained using an a-priori subset View full abstract»

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  • Evolving the morphology of a compound eye on a robot

    Publication Year: 1999 , Page(s): 127 - 134
    Cited by:  Papers (12)
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    Reports on an experiment in evolving the morphology of an artificial compound eye with 16 light sensors on a robot. A special robot was designed and constructed that is able to autonomously modify the angular positions of the individual light sensors within the compound eye. The task of the robot was to employ motion parallax to estimate a critical distance to obstacles. This task was achieved by adapting the morphology of the compound eye by an evolutionary algorithm while using a fixed neural network to control the robot View full abstract»

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  • Global localisation via sub-graph isomorphism

    Publication Year: 1999 , Page(s): 151 - 158
    Cited by:  Papers (1)
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    A novel approach to the global localisation problem for an autonomous mobile robot is presented. Instead of referring to traditional map-based techniques, we choose to extract a graph-like topological representation of the free space from occupancy grids, thus shifting the map-matching problem to a sub-graph isomorphism one. An efficient any-time algorithm is described in detail, and simulated experimental results are provided View full abstract»

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  • Knowing your place in real world environments

    Publication Year: 1999 , Page(s): 135 - 142
    Cited by:  Papers (2)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (636 KB)  

    The topic of mobile robot self-localisation is usually divided into the sub-problems of global localisation and position tracking. Both are now well understood individually, but few mobile robots can deal simultaneously with the two problems in large, complex environments. While efficient solutions have been found for metric maps, topological maps have, by nature of their compactness, the potential for representing environments which are several orders of magnitude larger than those which can be tractably navigated using metric maps. In this paper, we present a unified approach to global localisation and position tracking which is based on a topological map augmented with metric information. The method was validated through a series of experiments conducted in four real-world environments, including its integration into a complete navigating mobile robot. Quantitative performance measures were used to assess localisation quality versus computational efficiency. The results show that our robot can localise and navigate reliably in large, complex environments using only minimal computational resources View full abstract»

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  • Nonholonomic mobile robots - a new solution for path planning in changing environment

    Publication Year: 1999 , Page(s): 89 - 96
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    Presents theoretical analyses of different methods which can be used in online path generation for mobile robots with nonholonomic constraints in a partially known workspace. A new method is then introduced, which works very quickly and gives the optimal path in a complex environment. The algorithm of the presented method is based on A*-graph searching with the nodes placed in a discretized configuration space. This paper focuses on the analysis of different heuristic cost functions and introduces a new statement of this function. The presented method is equipped with procedures for fast path replanning-which is very useful in partially known workspaces. A series of simulation tests and experimental results of online control for a car-like robot are also discussed View full abstract»

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  • Mechanism and control of master-slave quadruped walking robot

    Publication Year: 1999 , Page(s): 9 - 16
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    This paper describes the mechanism and walking control of a proposed master-slave quadruped walking robot. The real time recognition of environment and the decision of control signal to each actuator are very important for the control of walking robot on rough terrain. Their techniques are not perfect at the present. Thus, we proposed a master-slave quadruped walking robot using radio control devices, which can efficiently use the recognition and control functions of human. We have already performed experiments for straight walking using a prototype of the master-slave quadruped walking robot. This robot can walk forward and backward on even terrain, and can get over the low steps, In this paper, we propose a curve walking and a rotation method of the master-slave quadruped walking robot, and describe experiments for the curve walking and rotation of the robot. The experimental results show the validity of the proposed method View full abstract»

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