Title
Active Alignment Control-based LED Communication for Underwater Robots
Abstract
Achieving and maintaining line-of-sight (LOS) is challenging for underwater optical communication systems, especially when the underlying platforms are mobile. In this work, we propose and demonstrate an active alignment controlbased LED-communication system that uses the DC value of the communication signal as feedback for LOS maintenance. Utilizing the uni-modal nature of the dependence of the light signal strength on local angles, we propose a novel triangular exploration algorithm, that does not require the knowledge of the underlying light intensity model, to maximize the signal strength that leads to achieving and maintaining LOS. The method maintains an equilateral triangle shape in the angle space for any three consecutive exploration points, while ensuring the consistency of exploration direction with the local gradient of signal strength. The effectiveness of the approach is first evaluated in simulation by comparison with extremum-seeking control, where the proposed approach shows a significant advantage in the convergence speed. The efficacy is further demonstrated experimentally, where an underwater robot is controlled by a joystick via LED communication.
Year
DOI
Venue
2020
10.1109/IROS45743.2020.9341442
2020 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)
Keywords
DocType
ISSN
active alignment control-based,underwater robot,line-of-sight,underwater optical communication systems,DC value,communication signal,LOS maintenance,uni-modal nature,light signal strength,local angles,light intensity model,equilateral triangle shape,angle space,consecutive exploration points,exploration direction,local gradient,LED communication,triangular exploration algorithm,active alignment control based LED-communication system,extremum-seeking control
Conference
2153-0858
ISBN
Citations 
PageRank 
978-1-7281-6213-3
1
0.41
References 
Authors
0
3
Name
Order
Citations
PageRank
Pratap Bhanu Solanki110.41
Shaunak D. Bopardikar215.48
Xiaobo Tan372.92