SPECIAL SEMINAR Friday, February 16

Carlotta Mummolo, PhD
Associate Research Scientist
Mechanical and Aerospace Engineering Department
New York University Tandon

Can we predict a fall? Mechanical principles of balance stability in legged systems with multiple contact interactions

In everyday life activities such as walking, stair climbing, or reaching for an object, human actions require proper whole-body coordination and the use of physical interactions with the environments so that balance is not compromised.  Humans can instinctively plan their contact interactions in time and space, and use them as intentional balance support for dynamic movements during various tasks.  However, it is very difficult to quantitatively predict the effects of different contact interactions on the balance stability of the human body.  This is in part due to the high dimensionality and redundancy of the human body system dynamics, but also to the lack of general and comprehensive mathematical definitions of the balance states of constrained legged systems.  In this talk, the concepts of balanced and falling states are redefined from a constrained dynamics perspective: a system in a balanced state can always come to a stop without ever altering its physical contacts; vice versa, a change of contacts is inevitable for a system in a falling state.  Based on these definitions, a balance stability criterion is presented, in which a contact-dependent threshold between balanced and falling states is identified in the state space of the center of mass of any given legged system (e.g., the human body, a biped robot, a human wearing a robotic exoskeleton).  A computational approach based on whole-body dynamics and optimization is used to quantify the stability thresholds of the given legged system in various contact configurations.  The proposed framework provides contact-specific “maps” of balanced states for any given legged system, useful for understanding the fundamental principles of balance preservation and recovery in humans, as well as the design of algorithmic principles for robot-assisted locomotion. 

Carlotta Mummolo received her bachelor and master degrees in Mechanical Engineering from Polytechnic of Bari (Italy) in 2009 and 2011, respectively, and a second master degree in Mechanical Engineering from New York University (NYU) in 2011.  In January 2016, she received two doctoral degrees through a joint Ph.D. program in Mechanical Engineering between Polytechnic of Bari and NYU.  She is currently an associate research scientist in the Mechanical and Aerospace Engineering Department at NYU Tandon, where she also teaches the graduate courses Simulation Tools for Mechatronics and Robotics, Introduction to Robot Mechanics, Robot Mobility, and the undergraduate course Automatic Control.  Her research interests are in the fields of dynamics, optimization, mechanisms and robotics, and biomechanics, with applications in the balance stability and locomotion of robotic and biological systems and their intersection.  She is a member of ASME, IEEE, and Society of Women Engineers and her work has been published in several journal articles and conference presentations.