Upload
shanae
View
48
Download
0
Tags:
Embed Size (px)
DESCRIPTION
GPS-Free Node Localization in Mobile Wireless Sensor Networks. H¨useyin Akcan 1 , Vassil Kriakov 1 ,Herv´e Br¨onnimann 1 , Alex Delis 2 1 CIS Department Polytechnic University 2 Dept. of Informatics & Telecom. University of Athens ACM MobiDE’06. Outline. Introductions - PowerPoint PPT Presentation
Citation preview
GPS-Free Node Localizationin Mobile Wireless Sensor Networks
H¨useyin Akcan1, Vassil Kriakov1,Herv´e Br¨onnimann1, Alex Delis2
1CIS Department Polytechnic University2Dept. of Informatics & Telecom. University of Athens
ACM MobiDE’06
Outline
Introductions Localization Algorithm Simulations Conclusion
Introduction
Wireless sensor networks are composed of hundreds sensor nodes.
Sensor nodes are capable of measuring various physical
values. are communicating with each other and
organizing themselves to achieve mission. find routing path by their relation between each
other.
Introduction
Many applications require sensor network mobility in environments.
Some place there are not deployed sensor. Ex.
The scene of a fire. Emergency incident.
Introduction Motivation
preserve network formation during directed mobility in mobile sensor networks.
Goals provide directional neighbor localization in a network wide coordinate system. work under fairly large motion and distance measurement errors. unaffect by the speed of nodes. work for any network size. support a stable network in mobility problems.
Introduction
Explore accident location
Introduction
Introduction Assumptions in this paper
Each mobile sensor node has a compass pointing North can measure the distance to their neighbors using (TOA). allows each node to move a specific distance in a specific
direction. has no additional positioning equipment or infrastructure is
required. Actuator, compass and distance measurements are
subject to errors caused by various real world disturbances.
Localization Algorithm
Core localization algorithm Verification algorithm Exceptional configurations
Localization Algorithm
d1
d2
d1
T=2
T=1
T=3
α2
V2v1
Localization Algorithm
Core localization algorithm
A
(X0 , Y0)
Bd1
A Bd2
α1
α2
V2v1
Localization Algorithm
A
(X0 , Y0)
Bd1
A Bd2
α1
(X1 , Y1)
Localization Algorithm
α2
V2v1
A
(X0 , Y0)
Bd1
A Bd2
α1
(X1 , Y1)
(X2 , Y2)
(X3 , Y3)
Localization Algorithm
Localization Algorithm
Localization Algorithm
CoreLocalization(n1, n2, v1,α1)
1: d1 inter-distance(n1, n2)
2: Move node n1 by v1 and α1
3: d2 inter-distance(n1, n2)
4: Retrieve v2 and α2 from n2
5: Calculate positions of n2 using equations (4),(5) and (6)
Localization Algorithm
α2
V2 v1
A
(X0 , Y0)
Bd1
AB d2
α1
(X1 , Y1)
(X2 , Y2)
(X3 , Y3)
Localization Algorithm
Two possible position
AB
AB A B
A B
Localization Algorithm Verification (NeighborList NL) 1: for each neighbor pair (m, n) in NL do 2: if m and n are neighbors then 3: dm,n measured inter-distance(m, n) 4: for each position pair {mi, nj | i, j = 1, 2} do 5: Compute Euclidean distance D between
mi and nj
6: if D = dm,n then 7: mark mi and nj as exact positions
Find dBC which are equal to d3.
Localization Algorithm
AB
AB A B
A B
CdBC
C
dBC
Localization Algorithm
Exceptional configurations If A=0 and B=0 then D=0
A
A
B
B
B
B
Localization Algorithm
Exceptional configurations If E2-DF<0 or G2-DH<0 Node skip this round and make necessary
adjustments.
Localization Algorithm
d1
d5
d2 d3
d4
T=1 T=2
V3
V2
V1
Simulations
Environment Compare with absolute position algorithm Sensor radio range 6 100 x 100 area 100 run
Each round random speed [0,5) random angle [0,2π)
Simulations
Simulations
Random movement
Simulations
Directed movement
Simulations
Directed trajectory of nodes performing
zig-zag movement.
Simulations
Absolute positioning algorithm
Simulations
Our localization algorithm
Conclusion
In this paper, they are the first GPS-free localization algorithm
work on mobile nodes. propose a straightforward and robust algorithm
that requires only a single round of node movement to localize all neighbor nodes.