Legged robots are well suited t o walk on dif icult terrains at the expense of requiring complex control syst ems to walk even on flat surfaces. But simply walking on a fiat surface is not worth using a legged robot. I t should be assumed that walking on abrupt terrain is the typical situation for a legged robot. Wi th this premise in mind, we have developed a robust controller f o r a six-legg...

The Basilisk Lizard’s striking ability to sustain highly dynamic legged locomotion on a range of surfaces from hard-ground to water is a remarkable feat [1]. Most legged robots would have di culty emulating this animal’s ability to robustly locomote on yielding or deforming surfaces. Therefore, to explore the dynamics of legged locomotion in this regime, we are studying the design of a bio-insp...

In this paper, we report on a new stability analysis for hybrid legged locomotion systems based on factorization of return maps. We apply this analysis to a family of models of the Spring Loaded Inverted Pendulum (SLIP) with different leg recirculation strategies. We obtain a necessary condition for the asymptotic stability of those models, which is formulated as an exact algebraic expression d...

This thesis addresses the application of nonlinear optimization to three different problems in computer graphics: the generation of gait cycles for legged creatures, the generation of models of truss structures, and the generation of models of constant mean curvature structures. We first present work on the automatic motion generation for legged creatures. Our technique is a reformulation of sp...

Walter D. Goldberger and Ira Z. Rothstein Dept. of Physics, Yale University, New Haven CT 06520, USA Dept. of Physics, Carnegie Mellon University, Pittsburgh PA 15213, USA Abstract In this essay we introduce a theoretical framework designed to describe black hole dynamics. The difficulties in understanding such dynamics stems from the proliferation of scales involved when one attempts to simult...

Helicity was calculated in Hurricane Bonnie (1998) using tropospheric-deep dropsonde soundings from the Convection and Moisture Experiment conducted by NASA. Large helicity existed downshear of the storm center with respect to the ambient vertical wind shear. It was associated with veering, semi-circular hodographs created by strong, vortex-scale, radial-vertical flow induced by the shear. The ...

We consider three theorems in ergodic theory concerning a fixed aperiodic measure preserving transformation σ of a Lebesgue probability space (X,A, μ) and show that these theorems are all equivalent. Two of these results concern the existence of a partition of the space X with special properties. The third theorem asserts that the conjugates of σ are dense in the uniform topology on the space o...

We show that (under MA) for any c many dense sets in Laver forcing L there exists a ff-centered Q Ç L such that all the given dense sets are dense in Q . In particular, MA implies that L satisfies MA and does not collapse the continuum and the additivity of the Laver ideal is the continuum. The same is true for Miller forcing and for Mathias forcing. In the case of Miller forcing this involves ...

Hurricane intensification has been studied by scientists for decades and one phenomenon that appears to always accompany the intensification is the presence of hot towers of cumulous clouds that stretches to 15 km high, touching the top of the troposphere (Figure 1a &b). The hypothesis of Hot towers was first proposed in 1958 by Riehl and Malkus (Anthes, 1999), who wrote in conclusion from thei...