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Robotics and neuroscience: A rhythmic interaction ; ; Sepulchre, Rodolphe in Neural Networks (2008), 21(4), 577-583 At the crossing between motor control neuroscience and robotics system theory, the paper presents a rhythmic experiment that is amenable both to handy laboratory implementation and simple mathematical ... [more ▼] At the crossing between motor control neuroscience and robotics system theory, the paper presents a rhythmic experiment that is amenable both to handy laboratory implementation and simple mathematical modeling. The experiment is based on an impact juggling task, requiring the coordination of two upper-limb effectors and some phase-locking with the trajectories of one or several juggled objects. We describe the experiment, its implementation and the mathematical model used for the analysis. Our underlying research focuses on the role of sensory feedback in rhythmic tasks. In a robotic implementation of our experiment, we study the minimum feedback that is required to achieve robust control. A limited source of feedback, measuring only the impact times, is shown to give promising results. A second field of investigation concerns the human behavior in the same impact juggling task. We study how a variation of the tempo induces a transition between two distinct control strategies with different sensory feedback requirements. Analogies and differences between the robotic and human behaviors are obviously of high relevance in such a flexible setup. [less ▲] Detailed reference viewed: 16 (3 ULg)Rhythmic feedback control of a blind planar juggler ; ; Sepulchre, Rodolphe in IEEE Transactions on Robotics (2007), 23(4), 790-802 The paper considers the feedback stabilization of periodic orbits in a planar juggler. The juggler is "blind," i.e, he has no other sensing capabilities than the detection of impact times. The robustness ... [more ▼] The paper considers the feedback stabilization of periodic orbits in a planar juggler. The juggler is "blind," i.e, he has no other sensing capabilities than the detection of impact times. The robustness analysis of the proposed control suggests that the arms acceleration at impact is a crucial design parameter even though it plays no role in the stability analysis. Analytical results and convergence proofs are provided for a simplified model of the juggler. The control law is then adapted to a more accurate model and validated in an experimental setup. [less ▲] Detailed reference viewed: 34 (7 ULg)Sensorless stabilization of bounce juggling ; ; Sepulchre, Rodolphe in IEEE Transactions on Robotics (2006), 22(1), 147-159 The paper studies the properties of a sinusoidally vibrating wedge billiard as a model for 2-D bounce juggling. It is shown that some periodic orbits that are unstable in the elastic fixed wedge become ... [more ▼] The paper studies the properties of a sinusoidally vibrating wedge billiard as a model for 2-D bounce juggling. It is shown that some periodic orbits that are unstable in the elastic fixed wedge become exponentially stable in the nonelastic vibrating wedge. These orbits are linked with certain classical juggling patterns, providing an interesting benchmark for the study of the frequency-locking properties in human rhythmic tasks. Experimental results on sensorless stabilization of juggling patterns are described. [less ▲] Detailed reference viewed: 31 (4 ULg)Timing Feedback Control of a Rhythmic System ; ; Sepulchre, Rodolphe in Proceedings of the 44th IEEE Conference on Decision and Control and European Control Conference 2005 (2005, December) This paper addresses the question relative to the role of sensory feedback in rhythmic tasks. We study the properties of a sinusoidally vibrating wedge-billiard as a model for 2-D bounce juggling. If this ... [more ▼] This paper addresses the question relative to the role of sensory feedback in rhythmic tasks. We study the properties of a sinusoidally vibrating wedge-billiard as a model for 2-D bounce juggling. If this wedge is actuated with an harmonic sinusoidal input, it has been shown that some periodic orbits are exponentially stable. This paper explores an intuitive method to enlarge the parametric stability region of the simplest of these orbits. Accurate processing of timing is proven to be an important key to achieve frequency-locking in rhythmic tasks. [less ▲] Detailed reference viewed: 5 (0 ULg)OPEN-LOOP STABILIZATION OF 2D IMPACT JUGGLING ; ; Sepulchre, Rodolphe in Proceedings of 6th IFAC Symposium on Nonlinear Control Systems (2004, September) The paper studies the properties of a sinusoidally vibrating wedge billiard as a model for 2D impact juggling. It is shown that some periodic orbits that are unstable in the elastic xed wedge become ... [more ▼] The paper studies the properties of a sinusoidally vibrating wedge billiard as a model for 2D impact juggling. It is shown that some periodic orbits that are unstable in the elastic xed wedge become exponentially stable in the (non-)elastic vibrating wedge. These orbits are linked with some classical juggling patterns, providing an interesting benchmark for the study of the frequency-locking properties in human rhythmic tasks. [less ▲] Detailed reference viewed: 9 (0 ULg)Mission du team belge au Kosovo: science et justice à la rencontre du drame humain. Premiers résultats ; Boxho, Philippe ; et al in Revue de Biométrie humaine et d'Anthropologie (2000) Detailed reference viewed: 36 (5 ULg) |
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