LCSR Seminar: Shai Revzen “Geometric Mechanics and Robots with Multiple Contacts”
Modeling and control problems generally get harder the more Degrees of Freedom (DoF) are involved, suggesting that moving with many legs or grasping with many fingers should be difficult to describe. In this talk I will show how insights from the theory of geometric mechanics, a theory developed about 20-30 years ago by Marsden, Ostrowski, and Bloch, might turn that notion on its head. I will motivate the claim that when enough legs contact the ground, the complexity associated with momentum is gone, to be replaced by a problem of slipping contacts. In this regime, equations of motion are replaced by a “connection” which is both simple to estimate in a data driven form, and easy to simulate by adopting some non-conventional friction models. The talk will contain a brief intro to geometric mechanics, and consist mostly of results showing that: (i) this class of models is more general than may seem at first; (ii) they can be used for very rapid hardware in the loop gait optimization of both simple and complex robots; (iii) they motivate a simple motion model that fits experimental results remarkably well. If successful, this research agenda could improve motion planning speeds for multi-contact robotic systems by several orders of magnitude, and explain how simple animals can move so well with many limbs.
Shai Revzen is an Assistant Professor in the University of Michigan, Ann Arbor. His primary appointment is in the department of Electrical Engineering and Computer Science in the College of Engineering. He holds a courtesy faculty appointment in the Department of Ecology and Evolutionary Biology, and is an Assistant Director of the Michigan Robotics Institute. He received his PhD in Integrative Biology from the University of California at Berkeley, and an M.Sc. in Computer Science from the Hebrew University in Jerusalem. In addition to his academic work, Shai was Chief Architect R&D of the convergent systems division of Harmonic Lightwaves (HLIT), and a co-founder of Bio-Systems Analysis, a biomedical technology start-up. As principal investigator of the Biologically Inspired Robotics and Dynamical Systems (BIRDS) lab, Shai sets the research agenda and approach of the lab: a focus on fundamental science, realizing its transformative influence on robotics and other technology. Work in the lab is equally split between robotics, mathematics, and biology.