Events Calendar

Center of Autonomy and AI, Center for Cyber-Physical Systems and the Internet of Things, and Ming Hsieh Institute Seminar Series

Speaker: Aaron Johnson, Mechanical Engineering at Carnegie Mellon University

Talk Title: The Trouble with Contact: State Estimation and Control Generation for Discontinuous Systems

Series: Center for Cyber-Physical Systems and Internet of Things

Abstract: Contact with the outside world is challenging for robots due to its inherently discontinuous nature -- when a foot or hand is touching a surface the forces are completely different than if it is just above the surface. However, most of our computational and analytic tools for planning, learning, and control assume continuous (if not smooth or even linear) systems. Simple models of contact make assumptions (like plasticity and coulomb friction) that are known to not only be wrong physically but also inconsistent. In this talk I will present techniques for overcoming these challenges in order to adapt smooth methods to systems that have changing contact conditions. In particular I will focus on two topics: First, I will present the "Salted Kalman Filter" for state estimation over hybrid systems. Second, I will show a few techniques for generating new controllers with changing contact conditions, using both higher-order direct collocation and hybrid iLQR.

Biography: Prof. Johnson is an Assistant Professor in Mechanical Engineering at Carnegie Mellon University, working on legged robots, adaptive controls, contact-rich manipulation, physics based planning & learning, and terrain manipulation as director of the Robomechanics Lab. Previously, his postdoc focused on convergent manipulation planning algorithms in the Personal Robotics Lab at Carnegie Mellon University. He received his PhD in 2014 on self-manipulation and dynamic behaviors on legged robots (among other things) in Kod*lab at the University of Pennsylvania. He is the recipient of the NSF Career award, the ARO Young Investigator Award, and the CMU George Tallman Ladd Research Award.

Host: Pierluigi Nuzzo and Feifei Qian

Webcast: https://usc.zoom.us/webinar/register/WN_zyIBh_1gQLmKpMJG0GyLxw

Location: Online

WebCast Link: https://usc.zoom.us/webinar/register/WN_zyIBh_1gQLmKpMJG0GyLxw

Audiences: Everyone Is Invited

Contact: Talyia White