Gaits and Nonsmooth Nonlinear Normal Modes for Robotic Legged Locomotion

Abstract

In my research, I seek to systematically exploit mechanical dynamics to make future robots faster, more efficient, and more agile.  Drawing inspiration from biology and biomechanics, I design and control robots whose motion emerges in great part passively from the interaction of inertia, gravity, and elastic oscillations.  Energy is stored and returned periodically in springs and other dynamic elements, and continuous motion is merely initiated and shaped through the active actuator inputs.  In this context, I am particularly interested in questions of gait selection.  Should a legged robot use different gaits at different desired speeds?  If so, what constitutes these gaits, what causes their existence, and how do they relate to gaits observed in biology?

In this talk, I want to highlight a potential relationship between fully passive mechanical oscillation modes that exist in highly simplified and energetically conservative models of legged systems and the gaits that we can observe in humans, animals, and in actual legged robots.  I also want to discuss how these nonsmooth nonlinear normal modes can be used as a basis to develop energy optimal gaits for legged robotic systems.

Biography

David Remy (David, He,https://youtu.be/1h0EGkcXUes?t=34 ) is a Full Professor at the Institute for Nonlinear Mechanics at the University of Stuttgart in Germany.  He received his Ph.D. in 2011 from ETH Zurich (Prof. Roland Siegwart), and holds a M.Sc. in Mechanical Engineering from the University of Wisconsin, Madison and a Diploma in Engineering Cybernetics from the University of Stuttgart.  Prior to his appointment in Stuttgart, Dr. Remy was an Associate Professor at the University of Michigan, Ann Arbor.  He is a member of the German National Academic Foundation and a recipient of the NSF CAREER award.  His research interests include the design, simulation, and control of legged robots, exoskeletons, and other nonlinear systems.  Drawing inspiration from biology and biomechanics, he is particularly interested in the effects and exploitation of natural dynamic motions, the role of different gaits, and the possibility of force/torque controllable systems; both in conceptual models and in hardware realizations.