Dynamics of dry granular avalanches
Raphael Fischer, Philippe Gondret, Bernard Perrin, and Marc Rabaud
A fine analysis of the statistics of dry granular avalanches in a rotating drum setup reveals that, beyond the fluctuations, the angle at which an avalanche ends is correlated experimentally to the angle at which the avalanche starts. This correlation resulting from inertia defines an intermediate n ... [Phys. Rev. E 78, 021302 (2008)] published Tue Aug 5, 2008.
Static of Parallel Manipulators and Closeness to Singularity
J. Hubert and J.-P. Merlet
Singularity is a major problem for parallel robots as in these configurations the robot cannot be controlled, and there may be infinite forces/torques in its joints, possibly leading to a robot breakdown. In the recent years classification and detection of singularities have made large progress. How ... [J. Mechanisms Robotics 1, 011011 (2008)] published Tue Aug 5, 2008.
A Biarticulated Robotic Leg for Jumping Movements: Theory and Experiments
J. BabiC, Bokman Lim, D. OmrCen, J. LenarCiC, and F. C. Park
This paper investigates the extent to which biarticular actuation mechanismsspring-driven redundant actuation schemes that extend over two joints, similar in function to biarticular muscles found in legged animalsimprove the performance of jumping and other fast explosive robot movements. Robust num ... [J. Mechanisms Robotics 1, 011013 (2008)] published Tue Aug 5, 2008.
Singularity-Robust Inverse Kinematics Using Lagrange Multiplier for Redundant Manipulators
Youngjin Choi
In this paper, a singularity-robust inverse kinematics is newly suggested by using a Lagrange multiplier for redundant manipulator systems. Two tasks are considered with priority orders under the assumption that a primary task has no singularity. First, an inverse kinematics problem is formulated to ... [J. Dyn. Sys., Meas., Control 130, 051009 (2008)] published Mon Aug 4, 2008.
Iterative Learning Velocity and Tension Control for Single Span Axially Moving Materials
Haiyu Zhao and Christopher D. Rahn
Precise tension and speed control of axially moving material systems enables high speed processing of paper, plastics, fibers, and films. A single span model is developed that includes distributed longitudinal vibration, a torque-controlled roller at the left boundary, and a speed-controlled roller ... [J. Dyn. Sys., Meas., Control 130, 051003 (2008)] published Fri Aug 1, 2008.