Updating Position Estimate Of Mobile Robots In Curvilinear Environments Via Range Measures

This paper addresses the problem of updating a rough, odometric estimate of the pose of mobile robot, by means of a single range measure. The linearization errors, typical in curvilinear environments, often make the Extended Kalman (EK) estimate unreliable. Therefore, a second-order method is proposed, in which the measurement result is approximated in terms of a two-degree function of the pose estimate error (instead of a linear one). Experiments conducted on a real robot navigating within a curvilinear environment are reported, showing that the errors in the updated estimate, provided by the proposed method, are significantly lower than the errors in the EK estimate. 1. Introduction While navigating, a mobile robot is provided with a rough position estimate by means of its odometer. In order to avoid that estimation errors accumulate unrestrictedly, external sensor data are needed to recalibrate the robot position with respect to the navigation environment. Some approaches use arti..

Line Localization From Single catadioptric Image

International audienceIndoor environments often contain several line segments. The 3D reconstruction of such environ- ments can thus be reduced to the localization of lines in the 3D space. Multi-view reconstruction requires the solution of the correspondence problem. The use of a single image to localize space lines is attractive, since the correspondence problem can be avoided. However, using a central camera the line localization from sin- gle image is an ill-posed problem, because there are infinitely many lines sharing the same image. In this work we relaxed the constraint on single viewpoint imaging and considered a wide class of non-central catadioptric cameras, constituted by an axial symmetric mirror and a perspective camera placed at a generic relative position. In the paper we report the results of our study on line localization for such cameras, reporting the conditions that allow a line to be localized from a single image. We show how the analysis can be extended to other classes of non-central devices sharing a similar imaging model. We also present a brief overview of the main algorithms for line localization from single image that have been proposed

An Information-Based Exploration Strategy for Environment Mapping with Mobile Robots

The availability of efficient mapping systems to produce accurate representations of initially unknown environments is recognized as one of the main requirements for autonomous mobile robots. In this paper, we present an efficient mapping system that has been implemented on a mobile robot equipped with a laser range scanner. The system builds geometrical point-based maps of environments employing an information-based exploration strategy that determines the best observation positions by taking into account both the distance travelled and the information gathered. Our exploration strategy, being based on solid mathematical foundations, differs from many ad hoc exploration strategies proposed in literature. We present: (a) the theoretical aspects of the criterion for determining the best observation positions for a robot building a map, (b) the implementation of a mapping system that uses the proposed criterion, and (c) the experimental validation of our approach

Uncalibrated visual odometry for ground plane motion without auto-calibration

International audienceno abstrac

On the localization of straight lines in 3D space from single 2D images

The reconstruction of 3D scenes constituted by straight lines can find many applications both in Computer vision and in Mobile robotics. Most of the approaches to this problem involve either stereo-vision or the analysis of a sequence of images taken from different viewpoints: in both cases, the solution of the correspondence problem is required. This paper studies the localization of straight lines in 3D space from single 2D images, acquired by a catadioptric camera. In general, using a noncentral camera, the viewing rays starting from the points of a straight line constitute a non-planar surface: if this non-planar surface only contains one straight line, other than the viewing rays, then the straight line can univocally be localized. Some conditions for the univocal localization of straight lines are derived. A simple technique for the straight line localization is presented, and some preliminary experimental results are discussed