 
Summary: The Center for Control, Dynamical Systems, and Computation
University of California at Santa Barbara
Presents
Metastable LeggedRobot Locomotion
Katie Byl
(Faculty Candidate)
Tuesday, April 14, 2009 9:30 am HFH 4164
Abstract:
A variety of impressive approaches to legged locomotion exist; however, the science of legged robotics
is still far from demonstrating a solution which performs with a level of flexibility, reliably and careful
foot placement that would enable practical locomotion on the variety of rough and intermittent terrain
humans negotiate with ease on a regular basis. In this talk, we present a methodology for designing
control algorithms to move a legged robot across such terrain in a qualitatively satisfying manner,
without falling down very often. We feel the definition of a meaningful metric for legged locomotion is
a useful goal in and of itself. Specifically, the mean firstpassage time (MFPT), also called the mean
time to failure (MTTF), is an intuitively practical cost function to optimize for a legged robot, and we
present a systematic, mathematical process for obtaining estimates of this MFPT metric. Of particular
significance, our models of walking on stochastically rough terrain generally result in dynamics with
a fast mixing time, where initial conditions are largely "forgotten" within 1 to 3 steps. Additionally, we
can often find a nearoptimal solution for motion planning using only a short timehorizon lookahead.
