1. BACK-TRACKING BASED SENSOR DEPLOYMENT BY A ROBOT TEAM Proceedings of the 7 th IEEE Communications Society Conference on Sensor Mesh and Ad-Hoc Communications and Networks (SECON 2010) Authors: Greg Fletcher; Xu Li; Amiya Nayak; Ivan Stojmenovic; Summary: Robert Burden

2. OBJECTIVES Goal of Work Minimize movement by robots while deploying a sensor network Problems Addressed 1.SLeast Recently Visited 2.(LRV)t 3.Self healing Technology Built On Least Recently Visited (LRV) Snake-Like Deployment (SLD) Aim of Work Expand existing carrier-based sensor placement algorithms to teams

3. PREVIOUS WORK Least Recently VisitedSnake-Like Deployment Deployed sensors recommend future moves Excessive movement to explore and ROI Eventually produces full coverage Doesn’t Guarantee Full Coverage Efficient movement due to lack of backtracking

4. ASSUMPTIONS 1.n number of mobile robotics carrying a sufficient number of sensors to cover the ROI 2.Robots are distributed randomly throughout the ROI 3.Robots are aware of their position via GPS or similar positioning systems 4.Robots have laser range-finding ability in a 360 degree view 5.Sensors have a fixed sensing range & periodically transmit a “hello” containing position and other important information. 6.Sensors know about their neighborhood changes (node failure)

5. CONTRIBUTIONS Back-Tracking Deployment (BTD)

6. CONTRIBUTIONS Multi Robot Back-Tracking Deployment (BTD)

7. CONTRIBUTIONS Self Healing in Back-Tracking Deployment (BTD)

8. IMPACT According to Google Scholar this paper has been cited 16 times mostly self citations by Dr. Li Xu. Major part of the first paper I presented “Sensor Deployment by Robot in an Unknown Orthogonal Environment”

9. EVALUATION 1.Simulation 2.Statistical Analysis

10. EVALUATION Coverage Ratio (CR): The average ratio of the number occupied grid points to the total number of grid points at algorithm termination time. Robot Moves (RV): The average number of movements made by each robot during simulation. Robot Messages (RM): The average number of messages generated by each robot during simulation. Sensor Messages (SM): The total number of messages transmitted by sensors during simulation.

11. EVALUATION

12. FUTURE WORK Placing sensors in a loop while sensors are failuring can result in a non-terminating algorithm. Sensing hole “donuts” can result in false dead ends which leads to less then 100% coverage. It is possible for one robot to preform the majority of deployment in a multiple robot deployment scenario.

13. DISCUSSION How can we deal with the load balancing issue in multiple robot deployment?

14. CITATION F LETCHER, G REG, ET AL. "B ACK - TRACKING BASED SENSOR DEPLOYMENT BY A ROBOT TEAM." S ENSOR M ESH AND A D H OC C OMMUNICATIONS AND N ETWORKS (SECON), 2010 7 TH A NNUAL IEEE C OMMUNICATIONS S OCIETY C ONFERENCE ON. IEEE, 2010.