dynamic leadership protocol for s-nets gregory j. barlow, thomas c. henderson, andrew l. nelson, and...
Post on 20-Dec-2015
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Dynamic LeadershipProtocol for S-nets
Gregory J. Barlow, Thomas C. Henderson, Andrew L. Nelson, and Edward Grant
North Carolina State University
University of Utah
Introduction
• Distributed sensing is an alternative to using large amounts of on-board sensors on mobile robots
• Smart sensor networks can be used for distributed sensing, communication, and computation
• This work presents a leadership protocol that forms clusters in a smart sensor network for distributed sensing
S-nets
• S-element: a stationary agent capable of computation, communication, and sensing. S-elements have a limited communication range.
• S-net: a network of spatially distributed S-elements.
• S-cluster: a group of S-elements with one agent as the leader.
Dynamic S-net Leadership Algorithm
• The DSNL algorithm is a distributed algorithm run by each S-element
• Each S-element must have a unique identification number
• Our goal is to form S-clusters with one leader for each cluster
• As S-elements are added to and removed from the S-net, clusters should update dynamically
S-element State
id_num unique ID number
leader Boolean, whether node is a leader
resolved Boolean, whether node is resolved
nodelist list of all nodes in communication range
remaining list of unresolved nodes
cluster list of resolved nodes in the cluster
lastcluster list of nodes in the cluster during the
previous generation
noncluster list of resolved nodes not in the cluster
DSNL Algorithm
Update lists of S-elements
Resolve the node’s leadership status
Resolve nodes in remaining
Execute task code once resolved
Objectives
1. The node that has the lowest ID number of all unresolved nodes in communication range should resolve as a leader
2. Any node that is in communication range of a leader should resolve as a follower
3. Every node should be a leader or a follower
4. When a follower is removed, its leader should remove it from cluster
5. When a node’s leader is removed, that node should re-resolve
S-nets implementation in simulation
S-nets implementation in simulation
Time
Node
1 2 3 4
0
1 L L
4 L L F F
10 L L
12 L L FL = leader, F = follower
S-net implementation using a robot colony
S-nets implementation using 20 S-elements
Conclusions
• We developed a leadership protocol for S-nets that allows dynamic updating of clusters
• We also developed an implementation of algorithm for embedded systems
• We successfully tested the leadership protocol in simulation and on a colony of mobile robots