Sébastien Druon

Dual position control strategies using the cooperative dual task-space framework

We propose a set of control strategies for performing two arm manipulation with the goal of simplifying the task definition. In order to develop these strategies we propose a new representation, derived from the cooperative task-space, in the dual quaternion domain. The result is a compact and “singularity free” representation for two arm systems, named cooperative dual task-space. All the proposed control strategies share the same general scheme and are derived by using an analytical approach. Moreover, the mathematical treatment is given in a coherent and systematic fashion, and thus other strategies may be derived using the same argument. Experimental results show the effectiveness and usefulness of the cooperative dual task-space framework and the proposed control strategies.

Fmri-based robotic embodiment: Controlling a humanoid robot by thought using real-time fmri

We present a robotic embodiment experiment based on real-time functional magnetic resonance imaging (rt-fMRI). In this study, fMRI is used as an input device to identify a subjects intentions and convert them into actions performed by a humanoid robot. The process, based on motor imagery, has allowed four subjects located in Israel to control a HOAP3 humanoid robot in France, in a relatively natural manner, experiencing the whole experiment through the eyes of the robot. Motor imagery or movement of the left hand, the right hand, or the legs were used to control the robotic motions of left, right, or walk forward, respectively.

3D datasets segmentation based on local attribute variation

We present a Graph-based method for low-level segmentation of unfiltered 3D data. The core of this approach is based on the construction of a local neighborhood structure and its recursive subdivision. The Minimum Spanning Tree (MST) is the graph support used to measure the attribute variation through the region. The subdivision criterion relies on the evidence for a boundary between two partitions, which is detected through MST edge analysis. Although our algorithm converges to a local minimum, our experiments show that it produces segments that satisfy global properties. We assume that the 3D image is composed of regions homogeneous according to some criterion (color, curvature, etc.), but no assumption about noise, nor spatial repartition/shape of the regions or points is made. Robustness is achieved by choosing the appropriate neighborhood and the analysis of noise impact on the MST construction. We demonstrate the performance of our algorithm with experimental results on real images.

Hierarchical segmentation for unstructured and unfiltered range images

We present a method for the segmentation of unstructured and unfiltered 3D data. The core of this approach is based on the construction of a local neighborhood structure and its recursive subdivision. 3D points will be organized into groups according to their spatial proximity, but also to their similarity in the attribute space. Our method is robust to noise, missing data, and local anomalies thanks to the organization of the points into a minimal spanning tree in attribute space. We assume that the 3D image is composed of regions homogeneous according to some criterion (color, curvature, etc.), but no assumption about noise, nor spatial repartition/shape of the regions or points is made. Thus, this approach can be applied to a wide variety of segmentation problems, unlike most existing specialized methods. We demonstrate the performance of our algorithm with experimental results on real range images.

Human centered system for computer aided replication of sculptures

The paper presents a technical solution for manually making replication of sculptures in real material from a numerical representation of the original work. This solution is based on a human centered system that provides an alternative to current techniques used in the art domain. This paper is focused on the presentation of the main capabilities of the system: functional and hardware characteristics, techniques for computer aided gesture.