[Colloq] REMINDER: Hiring Talk - Marty Vona, Friday, Feb. 20

[Rachel Kalweit]

Hiring talk: Marty Vona, MIT

Date and Time: Friday, February 20 at 1:30 in 366WVH

Title: Virtual Articulations for Coordinated Motion in High-DoF Robots

Abstract:
Usually we consider the kinematic topology of a robot to be  
immutable.  What if we were to allow virtual modifications, such as  
adding extra joints and links? (*) These "virtual articulations" can  
help address several current challenges in robotics.  In this talk I  
focus on their use as the basis for a new kind of expressive, rapid,  
and generic graphical interface for operating coordinated motions in  
robots with 10s to 100s of joints.  With this interface the operator  
may construct virtual articulations and inter-connect them with a  
model of the actual robot.  Virtual links represent task-relevant  
coordinate frames; virtual joints parametrize task motion, and, by  
closing cycles in the kinematic graph, constrain coordinated motions.

I will show hardware results where NASA's 36-DoF All Terrain Hex  
Limbed Extra Terrestrial Explorer (ATHLETE) executes a variety of  
previously challenging coordinated motion tasks, and also real-time  
simulations of a revolute-jointed modular robot with over 270 joints  
(actual and virtual) and 90 kinematic cycles.

These results are all based on a new interactive articulated robot  
simulator that supports dynamic and arbitrary closed chain kinematic  
topology with a varied catalog of joint types.  I cover core  
challenges in handling arbitrary topology, supporting the catalog of  
joints, and scaling to large numbers of DoF with both convenience and  
speed.  I introduce the idea of virtual kinematic abstraction for  
hierarchically managing complexity: Just as the implementation of an  
algorithm can be abstracted behind a compact interface, a potentially  
complicated kinematic sub-assembly can in some contexts be replaced by  
a less complex virtual stand-in.  Motion for the enclosing assembly is  
computed using the stand-in, which then drives the abstracted sub-
assembly.

(*) "Links" are approximately rigid bodies (e.g. your forearm), and  
correspond to the vertices in a kinematic graph; joints (e.g. your  
elbow) are the graph edges. The degrees-of-freedom (DoF) of a joint is  
the dimension of its mobility space.


SPEAKER BIO: Marsette Vona is a Ph.D. candidate in EECS at MIT CSAIL  
with Professor Daniela Rus.  His current work explores theory and  
applications for virtual articulations in robotics, operations  
interface software and hardware for exploration robots, and reliable  
compliant/proprioceptive climbing and walking strategies. From 2001 to  
2003 Marsette was a software developer at NASA/JPL, where he helped  
build the award-winning science operations interface for the Mars  
Exploration Rover mission.  His 2001 M.S. in EECS at MIT was on new  
techniques in precision metrology for machine tools, and his 1999 B.A.  
thesis in CS at Dartmouth College described a self-reconfiguring robot  
system based on compressing cube modules.

Host: Jay Aslam