invited talk: sensor deployment strategies for indoor robot navigation

Sensor-Deployment Strategies for

Indoor Robot Navigation

Aaron Chun-Han Lin 林均翰

Research Center for Information Technology Innovation Academia Sinica

Tel: 886-2-2787-2335 Fax: 886-2-2787-2372

Email: chunhan@citi.sinica.edu.tw

Previous Project

2011/8/11 2

ITRI project

Demo video

Sensor-Deployment Strategies for

Indoor Robot Navigation

Sensor

2011/8/11 3

Detection

Display

Embedded system

15-20%

cost

Market prediction of MEMS sensor on cellular phone

Wireless Sensor Network (WSN)

2011/8/11 4

Crossbow Mica2

Sense: light, motion, temperature, magnetic fields, gravity, humidity,

vibration, pressure, electrical fields, sound, ...

Project Testbed

2011/8/11 5

http://fiji.eecs.harvard.edu

/Volcano

http://db.csail.mit.edu/

http://www2.ece.ohio-state.edu/~ekici/

Harvard moteLab

COMMON Sense project

http://www.csail.mit.edu/

Importance of Deployment Technique

2011/8/11 6

Coverage

Detection ratio

Connectivity

Fault tolerance

…

Lifetime

Energy

Maintenance

Deployment cost

Design of Deployment Technique

2011/8/11 7

Various WSN systems

Different requirements

Developing 3 techniques

Indoor robot navigation

Debris-flow observation

Environment surveillance

Robot

2011/8/11 8

Routine service

2011/8/11 9

Space navigation

Security

Housekeeping

Delivery

Medical

…

http://www.worldrobotics.org/

Indoor Robot

2011/8/11 10

Localization

Positioning sensor

A set of sensors can

provide localization

service

Wireless

Infrastructure

Coverage

Robot Navigation

Challenge

2011/8/11 11

Traditional deployment

Full coverage

Tradeoff

Cost Coverage

How

Reducing sensor

Where

Keeping coverage

Acceptable error

Positioning sensor

Error Model

2011/8/11 12

Target model

x’ = x + d cos(q+r)

y’ = y + d sin(q+r)

q ’=(q+r) mod 2p

Actual configuration P(f)

Configuration error

err(f)=max(P(f) – f)

|err(f)|

=|max(P(f) – f)|

=(max((P(x) – x)2 +

(P(y) – y)2))1/2 Positioning sensor

Minimum Deployment-Set Problem

2011/8/11 13

MDS (G, Errmax)

Width of hallway

Width of track

…

The minimum

deployment-set problem is

NP-hard

Vertex cover problem

Deployment Procedure

2011/8/11 14

Map

Track

Deployment strategy

Initial Construction

2011/8/11 15

Divide graph

Estimate error

Compute number

Complexity Probability

Decide location

I-EVEN

I-MAX

1

2 1 3

Even

1

2 1 3

Max

Refinement

2011/8/11 16

Combine sub-graph

Confinement region

Circular route

Tree-based

Breadth-first

Utility-based

Performance Evaluation

2011/8/11 17

ITRI

Cricket

Size of Deployment Set

2011/8/11 18

Refinement ratio

Improvement ratio

Configuration Error

2011/8/11 19

Average Variance

Conclusion

2011/8/11 20

Sensor-deployment strategies for indoor robot navigation

Technique: sensor network

Problem: indoor robot navigation

Problem complexity

Deployment strategy

Performance