Graduate Exam Abstract

Shankarachary Ragi

Ph.D. Preliminary
April 8, 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 POMDP or a Dec-POMDP.

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