Dexterous Humanoid Whole-Body Manipulation by Pivoting

International audienc

Storage and Retrieval of a Squeezed Vacuum

Storage and retrieval of a squeezed vacuum was successfully demonstrated using electromagnetically induced transparency. 930ns of the squeezed vacuum pulse was incident on the laser cooled 87Rb atoms with an intense control light in a coherent state. When the squeezed vacuum pulse was slowed and spatially compressed in the cold atoms, the control light was switched off. After 3us of storage, the control light was switched on again and the squeezed vacuum was retrieved, as was confirmed using the time-domain homodyne method.Comment: 4 pages, 4 figures, to appear in Physical Review Letter

Motion Optimization of Robots, Application to HRP-2

International audienceThis paper presents an implementation of motion optimization for robots. Functional optimization is converted to parameter optimization using B-splines. Many non-linear constraints are considered such as contacts stability, motors limitations and regularized collision avoidance. Semi-infinite constraints are simply solved by a fine enought discretization on a grid. Energy consumption is minimized. Motion optimization is solved with the IPOPT optimization package. For fast and reliable optimization convergence, gradients are computed. Joint friction is taken into account and regularized to obtain a smooth problem. Efficiency of the proposed software is demonstrated for three dynamic motions of the 30 degrees-of-freedom humanoid robot HRP-2: a kicking motion, a throwing motion and a lifting motion

Humanoid feet trajectory generation for the reduction of the dynamical effects

Abstract-In this paper we present a different strategy for generating the trajectory of the swinging leg for a walking humanoid robot which takes into account the effects due to acceleration and velocities of the joints onto the center of mass of the robot. The trajectory of the leg is chosen to be constituted by two forth order polynomials interlaced by a via-point which satisfies the optimality criterium. This approach is validated on a humanoid robot HRP-2

Towards Autonomous Object Reconstruction for Visual Search by the Humanoid Robot HRP-2

International audienceThis paper deals with the problem of object reconstruction for visual search by a humanoid robot. Three problems necessary to achieve the behavior autonomously are considered: full-body motion generation according to a camera pose, general object representation for visual recognition and pose estimation, and far-away visual detection of an object. First we deal with the problem of generating full body motion for a HRP-2 humanoid robot to achieve camera pose given by a Next Best View algorithm. We use an optimization based approach including self-collision avoidance. This is made possible by a body to body distance function having a continuous gradient. The second problem has received a lot of attention for several decades, and we present a solution based on 3D vision together with SIFTs descriptor, making use of the information available from the robot. It is shown in this paper that one of the major limitation of this model is the perception distance. Thus a new approach based on a generative object model is presented to cope with more difficult situations. It relies on a local representation which allows handling occlusion as well as large scale and pose variations

Humanoid Vertical Jumping based on Force Feedback and Inertial Forces Optimization

Abstract — This paper proposes adapting human jumping dynamics to humanoid robotic structures. Data obtained from human jumping phases and decomposition together with ground reaction forces (GRF) are used as model references. Moreover, bodies inertial forces are used as task constraints while optimizing energy to determine the humanoid robot posture and improve its jumping performances. Index Terms — Humanoid robotics, jumping pattern generation, inertia optimization. I

3D object recognition using spin-images for a humanoid stereoscopic vision system

International audience— This paper presents a 3D object recognition method based on spin-images for a humanoid robot having a stereoscopic vision system. Spin-images have been proposed to search CAD models database, and use 3D range informations. In this context, the use of a vision system is taken into account through a multi-resolution approach. A method for quickly computing multi-resolution and interpolating spin-images is proposed. The results on simulation and on real data are given, and show the effectiveness of this method

Efficient reaching motion planning and execution for exploration by humanoid robots

Abstract—This paper presents a reaching motion planning and execution framework tailored for exploration missions by human-operated humanoid robots in hazardous environments such as nuclear plants. This framework offers low-level but practical autonomy that allows the robot to plan and execute simple tasks, such as reaching a target object, within a rea-sonable amount of time. The human operator benefits from the efficiency of the framework to maneuver the robot without waiting for the planning results for minutes. The efficiency improvement is achieved in the following two phases. In the first phase, a reaching motion is planned quickly through approximation of mass distribution and kinematic structure to apply analytical solutions of inverse kinematics. Supposing that the robot is working in environments not completely known, the proposed planner can use measured voxel maps. In the second phase, the planned path is executed while compensating the approximation error in real time without violating other constraints. We confirm through simulations that a reaching motion for the HRP-2 humanoid with 30 DOFs in a constrained environment with pipes is planned in around one second. The simulation results also validate the efficiency of execution with real-time error compensation. I