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Finding traversable paths using computer vision is one of the most important components of an intelligent mobile robot system. For a wall climbing robot that operates in an urban environment, it is essential to automatically detect surface types and orientations for switching between moving and climbing, and for applying different adhesive forces both to save energy and ensure its own safety. This...
This paper presents a new application in the field of rehabilitation robotics. It is part of a research project which consists of the development of a robotic leg prosthesis for above knee amputees. This application aims at providing real-time estimates of the prosthesis foot orientation with respect to ground. An Extended Kalman Filter (EKF) is used in order to estimate the foot orientation based...
Although research on localization of sound sources using microphone arrays has been carried out for years, providing such capabilities on robots is rather new. Artificial audition systems on robots currently exist, but no evaluation of the methods used to localize sound sources has yet been conducted. This paper presents an evaluation of various real-time audio localization algorithms using a medium-sized...
During simultaneous localization and mapping, geometrical constraints are established between map features. These constraints, introduced through measurements and motion prediction, produce a bending effect in the event of closing a large loop. In this paper we present a discussion of the bending problem for trajectory based representations. Furthermore, we propose a generic approach to reduce the...
A simple flexible technique is proposed to easily calibrate five intrinsic parameters a camera based on the three side lengths of a triangle. The technique only requires taking the template with a triangle, and matching the three vertices of the triangle between the template and its image. Analytical solution is given to guarantee algorithm accomplishment successfully. The essential relations for...
This paper describes an algorithm for estimating lane boundaries and curbs from a moving vehicle using noisy observations and a probabilistic model of curvature. The primary contribution of this paper is a curve model we call lateral uncertainty, which describes the uncertainty of a curve estimate along the lateral direction at various points on the curve, and does not attempt to capture uncertainty...
This paper considers the issue of calibrating a camera with narrow angular field of view using standard, perspective methods in computer vision. In doing so, the significance of perspective distortion both for camera calibration and for pose estimation is revealed. Since narrow angular field of view cameras make it difficult to obtain rich images in terms of perspectivity, the accuracy of the calibration...
In the context of 3-D scene modeling, this work aims at the accurate estimation of the pose of a close-range 3-D modeling device, in real-time and passively from its own images. This novel development makes it possible to abandon using inconvenient, expensive external positioning systems. The approach comprises an ego-motion algorithm tracking natural, distinctive features, concurrently with customary...
Model-based approaches in recognition and planning of robots work effectively, and these approaches can apply to model-less situation using autonomous model construction by an agent. There are problems about segmentation or shape fitting of various objects with different scales or shapes. In this paper, we construct a Head-mounted 3D multi sensor for 3D environment modeling and propose a method of...
Recently, classical pairwise Structure From Motion (SfM) techniques have been combined with non-linear global optimization (Bundle Adjustment, BA) over a sliding window to recursively provide camera pose and feature location estimation from long image sequences. Normally called Visual Odometry, these algorithms are nowadays able to estimate with impressive accuracy trajectories of hundreds of meters;...
Learning to recognize objects from a small number of example views is a difficult problem of robot vision, of particular importance to assistance robots who are taught by human users. Here we present an approach that combines bottom-up recognition of matching patterns and top-down estimation of pose parameters in a recurrent loop that improves on previous efforts to reconcile invariance of recognition...
A novel efficient trilateration algorithm is presented to estimate the position of a target object, such as a mobile robot, in a 2D or 3D space. The proposed algorithm is derived from a nonlinear least-squares formulation, and provides an optimal position estimate from a number (greater than or equal to the dimension of the environment) of reference points and corresponding distance measurements....
Robot vision has a lot to win as well with wide field of view induced by catadioptric cameras as with redundancy brought by stereovision. Merging these two characteristics in a single sensor is obtained by combining a single camera and multiple mirrors. This paper proposes a 3D model tracking algorithm that allows a robust tracking of 3D objects using stereo catadioptric images given by this sensor...
A major barrier preventing the wide employment of mobile networks of robots in tasks such as exploration, mapping, surveillance, and environmental monitoring is the lack of efficient and scalable multi-robot passive and active sensing (estimation) methodologies. The main reason for this is the absence of theoretical and practical tools that can provide computationally tractable methodologies which...
This paper describes an algorithm to estimate tremor and voluntary motion from measured motion data. Estimation is performed by means of an extended Kalman filter (EKF), which also estimates tremor parameters. Comparison of the proposed method with techniques described in the literature are conducted with two experimental data sets from tremor patients performing the same task, drawing a spiral. The...
This paper describes a method for removing adherent noises from image sequences. In outdoor environments, it is often the case that scenes taken by a camera are deteriorated because of adherent noises such as waterdrops on the surface of the lens-protecting glass of the camera. To solve this problem, our method takes advantage of image sequences captured with a moving camera whose motion is unknown...
We aim at developing a singer robot capable of listening to music with its own ??ears?? and interacting with a human's musical performance. Such a singer robot requires at least three functions: listening to the music, understanding what position in the music is being performed, and generating a singing voice. In this paper, we focus on the second function, that is, the capability to align an audio...
Accurate online localization is crucial for mobile robotics. In this paper, we describe a real-time image-based localization technique, which is based on a single calibrated camera. This can be supported by a second camera to improve accuracy and to provide the correct translational scale. Our goal is a robust and unbiased pose estimation in highly dynamic scenes on resource-limited systems. The presented...
This paper proposes real-time sound source orientation estimation based on orientation-extended amplitude beamforming (OE-ABF). To recognize a sound source orientation (such as face orientation) is an important function for a robot who can achieve natural human-robot interaction because the function is required to distinguish the human target from a robot or another person. We developed a sound source...
Usually, the identification of the dynamic parameters of robot makes use of the inverse dynamic model which is linear with respect to the parameters. This model is sampled while the robot is tracking exciting trajectories. This allows using linear least squares (LS) techniques to estimate the parameters. The efficiency of this method has been proved through experimental identifications of a lot of...
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