Walter Scott, Jr. College of Engineering

Graduate Exam Abstract

Shankarachary Ragi
Ph.D. Preliminary
Apr 08, 2013, 1:00 pm
ECE Conference Room
Cooperative Control of Mobile Sensors in Dynamic Environments
Abstract: We develop guidance algorithms to control mobile
sensors in dynamic environments. Our work covers
several applications: unmanned aerial vehicles
with on-board sensors for multi-target tracking,
autonomous amphibious vehicles with on-board
sensors for flood rescue support, and directional
sensors for maximizing information gain. We
consider centralized and decentralized settings.
In the centralized setting, the algorithm runs on
a notional central controller that collects
measurements from sensors, fuses the measurements,
and computes the control commands for the mobile
sensors. In the decentralized setting, the
algorithm runs on each mobile sensor
independently, and coordination among them is
achieved with the aid of communication. We pose
the centralized control problem as a partially
observable Markov decision process (POMDP), and
the decentralized control problem as a
decentralized POMDP (Dec-POMDP). Both POMDP and
Dec-POMDP are intractable to solve exactly;
therefore we adopt an approximation method called
nominal belief-state optimization to solve
(approximately) the control problems posed as a
Adviser: Edwin K. P. Chong
Co-Adviser: N/A
Non-ECE Member: Iuliana Oprea, Mathematics
Member 3: J. Rockey Luo, ECE
Addional Members: Diego Krapf, ECE
S. Ragi and E. K. P. Chong, "UAV path planning in a dynamic environment via partially observable Markov decision process," IEEE Transactions on Aerospace and Electronic Systems, accepted to appear.

S. Ragi and E. K. P. Chong, "Dynamic UAV path planning for multitarget tracking," in Proceedings of the 2012 American Control Conference, Montreal, Canada, June 27--29, 2012, Paper ThC04.3, pp. 3845--3850.

A. V. Weigel, S. Ragi, M. L. Reid, E. K. P. Chong, M. M. Tamkun, and D. Krapf, "Obstructed diffusion propagator analysis for single-particle tracking," Physical Review E, vol. 85, no. 4, paper 041924, April 2012.

S. Ragi and E. K. P. Chong, "Dynamic UAV path planning for multitarget tracking," presented (poster) at the 1st Southwest Workshop on Theory and Applications of Cyber-Physical Systems, Tucson, Arizona, March 10--11, 2011.
Program of Study:
ECE 520
ECE 526
ECE 614
ECE 652
MATH 517
MATH 676