October 31, 2014 / by Shai Revzen / In booklist

    Snake-Like Robots

    Limbless organisms such as snakes can navigate nearly all terrain. In particular, desert-dwelling sidewinder rattlesnakes (Crotalus cerastes) operate effectively on inclined granular media (such as sand dunes) that induce failure in field-tested limbless robots through slipping and pitching. Our laboratory experiments reveal that as granular incline angle increases, sidewinder rattlesnakes increase the length of their body in contact with the sand.

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    October 17, 2014 / by George Council / In news

    Accurate Control Hyperbolic

    The unsteady (nonautonomous) analog of a hyperbolic fixed point is a hyperbolic trajectory, whose importance is underscored by its attached stable and unstable manifolds, which have relevance in fluid flow barriers, chaotic basin boundaries, and the long-term behavior of the system. We develop a method for obtaining the unsteady control velocity which forces a hyperbolic trajectory to follow a user-prescribed variation with time.

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    October 17, 2014 / by George Council / In booklist

    Dynamics at a Switching Intersection: Hierarchy, Isonomy, and Multiple Sliding

    If a set of ordinary differential equations is discontinuous along some threshold, solutions can be found that are continuous, if sometimes multivalued. We show the extent to which unique solutions can be found in general cases when the threshold takes the form of finitely many intersecting manifolds.

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