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In this paper, we propose a new approach to visionbased robot control, called 2-1/2-D visual servoing, which avoids the respective drawbacks of classical position-based and imagebased visual servoing. Contrary to the position-based visual servoing, our scheme does not need any geometric three-dimensional (3-D) model of the object. Furthermore and contrary(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. However,(More)
  • Ezio Malis
  • IEEE International Conference on Robotics and…
  • 2004
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)
This paper concerns the stability analysis of a new class of model-free visual servoing methods. These methods are “model-free” since they are based on the estimation of the relative camera orientation between two views of an object without knowing its 3D model. The visual servoing is decoupled by controlling the rotation of the camera separately from the(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 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)
In this paper, we describe an efficient method to impose the constraints existing between the collineations between images which can be computed from a sequence of views of a planar structure. These constraints are usually not taken into account by multi-view techniques in order not to increase the computational complexity of the algorithms. However,(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 to(More)
In this paper, we investigate how to improve the robustness 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)