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— In this paper, several vision-based robot control methods are classified following an analogy with well known minimization methods. Comparing the rate of convergence between minimization algorithms helps us to understand the difference of performance of the control schemes. In particular, it is shown that standard vision-based control methods have in(More)
The objective of this paper is to propose a new homography-based approach to image-based visual tracking and servoing. The visual tracking algorithm proposed in the paper is based on a new efficient second-order minimization method. Theoretical analysis and comparative experiments with other tracking approaches show that the proposed method has a higher(More)
— The tracking algorithm presented in this paper is based on minimizing the sum-of-squared-difference between a given template and the current image. Theoretically, amongst all standard minimization algorithms, the Newton method has the highest local convergence rate since it is based on a second-order Taylor series of the sum-of-squared-differences.(More)
This article investigates the use of time-of-flight (ToF) cameras in mapping tasks for autonomous mobile robots, in particular in simultaneous localization and mapping May et al.: 3D Mapping with Time-of-Flight Cameras • 935 (SLAM) tasks. Although ToF cameras are in principle an attractive type of sensor for three-dimensional (3D) mapping owing to their(More)
Classical visual servoing techniques need a strong a priori knowledge of the shape and the dimensions of the observed objects. In this paper, we present how the 2 1/2 D visual servoing scheme we have recently developed, can be used with unknown objects characterized by a set of points. Our scheme is based on the estimation of the camera displacement from(More)
— This paper describes a new image-based approach to tracking the 6dof trajectory of a stereo camera pair using a corresponding reference image pairs instead of explicit 3D feature reconstruction of the scene. A dense minimisation approach is employed which directly uses all grey-scale information available within the stereo pair (or stereo region) leading(More)
In this paper we propose a new vision-based robot control approach halfway between the classical position-based and image-based visual servoings. It allows to avoid their respective disadvantages. The homography between some planar feature points extracted from two images (corresponding to the current and desired camera poses) is computed at each iteration.(More)
In this paper, we investigate how to improve the ro-bustness of visual tracking methods with respect to generic lighting changes. We propose a new approach to the direct image alignment of either Lambertian or non-Lambertian objects under shadows, inter-reflections, glints as well as ambient, diffuse and specular reflections which may vary in power, type,(More)
— This paper describes a new image-based approach to tracking the 6 degrees of freedom trajec-tory of a stereo camera pair using a corresponding reference image pair whilst simultaneously determining pixel matching between consecutive images in a sequence. A dense minimisation approach is employed which directly uses all grey-scale information available(More)