The Robotics Institute
RI | Seminar | April 18

Robotics Institute Seminar, April 18
Time and Place | Seminar Abstract | Speaker Biography | Speaker Appointments

Dynamic Locomotion and Quasistatic Manipulation: Natural Physical Interaction for Graphical Characters and Humanoid Robots

Nancy Pollard
SCS Faculty Candidate
Currently Assistant Professor at Brown University

Time and Place

1305 Newell-Simon Hall
Refreshments 3:15 pm
Talk 3:30 pm


Animated human characters and humanoid robots constantly interact with their environment. Feet contact the ground during walking or running, a shoulder may be used to nudge open a door, and hands contact an object to grasp or manipulate it. Interactions such as these involve applying forces to an object or to the world in order to accomplish a task. Modeling these forces and ensuring that they are physically plausible, appropriate, or "humanlike" can help us to create motion that is effective and appears natural.

In this talk, I will look at interaction forces from three perspectives. First, I will show that a focus on plausible interaction forces can lead to a fast algorithm for optimizing dynamic motions such as leaping, swinging, and gymnastics. Second, I will explore the idea that our ability to detect whether animated motion is physically plausible actually may not be very good; I will show results of a user study that begins to capture how much graphics can "cheat" physics before people start to notice. Finally, I will describe how an analysis of interaction forces can be used to adapt human demonstrations of manipulation tasks to different object geometries in a way that ensures required contact forces will be reasonable. I will show examples of a humanoid robot performing quasistatic manipulation tasks based on a single human demonstration.

Speaker Biography

Nancy Pollard received her PhD from the artificial intelligence laboratory at MIT in 1994. She is currently an assistant professor in the Computer Science Department at Brown University. One goal of her research is to create natural looking motion for animated human characters and humanoid robots. Toward this end, she has explored biologically motivated approaches for design, optimization, planning, and control. Nancy received an NSF CAREER award in 2001. She was program co-chair of the 2002 Symposium on Computer Animation, sponsored by ACM SIGGRAPH and Eurographics. Nancy has spent the last two years on sabbatical at CMU, and this talk will describe some of the work done during her visit.

Speaker Appointments

For appointments, please contact Jennifer Landefeld (

The Robotics Institute is part of the School of Computer Science, Carnegie Mellon University.