This is a reminder for the teatalk schedule today at 13.00.
See you soon!
- Cho
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Speaker: Dustin Webb (University of Utah)
Place: AA3195
Date/Time: 23 May 2014 @13.00 - 14.00
Title: Online Parameter Estimation via Real-Time Replanning of Continuous Gaussian POMDPs
Abstract:
An accurate dynamics model of a robot is an important ingredient of
many algorithms used to solve robotics problems, including motion
planning, control, localization, and mapping. Models derived from first
principles often contain parameters (e.g. mass, moment of inertia, arm
lengths, etc.) for which values are unknown. Those which cannot be
easily measured must be estimated from the observed behavior of the
robot. A good approach to address this problem is to plan control
policies for the robot that elicit maximal amounts of information about
the parameters of the system, while still achieving other objectives
specified for the robot. In case of parameters subject to drift, this
must be done continuously over the lifetime of the robot if costly
re-calibrations are to be avoided. In this paper, we introduce a new
method that formulates the parameter estimation problem as a continuous
partially-observable Markov decision process (POMDP), which plans
control policies that optimally trade-off the effort spent on learning
parameters and effort spent on achieving regular robot objectives
(exploration vs. exploitation), and allow for online, continual
parameter estimation. While POMDPs have, until recently, been mostly of
theoretical interest due to their inherent complexity, we build on
recent advances that allow continuous, Gaussian POMDPs to be
approximately-optimally solved in near-real-time rates. We show that the
computed control policies lead to improved convergence of the belief of
the parameters compared to system identification approaches based on
applying random controls.
Dustin J. Webb, Kyle L. Crandall and Jur van den Berg. Online
Parameter Estimation via Real-Time Replanning of Continuous Gaussian
POMDPs. ICRA 2014. http://arl.cs.utah.edu/pubs/ICRA2014-ope.pdf