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Simultaneous Localization and Mobile Robot Navigation in a Hybrid Sensor Network

Suresh Shenoy and Jindong Tan

Michigan Technological University

Intelligent Robots and Systems (IROS 2005).

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Outline

• Introduction• Simultaneous Localization & Navigation• Simulation• Conclusions

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Introduction

• The static sensors around the event may The static sensors around the event may request the mobile sensor/robots to navigate request the mobile sensor/robots to navigate themselvesthemselves

• The location information is important for the The location information is important for the navigation of mobile robotsnavigation of mobile robots

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Introduction

• Localization algorithmLocalization algorithm• Range basedRange based

• Add additional hardware (e.g: GPS)Add additional hardware (e.g: GPS)• Range-free basedRange-free based

• Location information can be obtainedLocation information can be obtained• RSSIRSSI• Time of arrival or time difference of arrivTime of arrival or time difference of arriv

alal

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Assumption

• The mobile robots are equipped with GPS The mobile robots are equipped with GPS • The mobile robots are equipped with more The mobile robots are equipped with more

resource such as sensor, power, computationresource such as sensor, power, computation

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Goal

N3

N8N6

N12

N15N2

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Mobility Based Range-Free Localization

A

(x,y)

Bounding box

B.box = {(x, y, range) : (xmin, xmax, ymin, ymax)}

Communication range

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Mobility Based Range-Free Localization

A

(x,y)

B.box = {(xmin, xmax, ymin, ymax)∩(xmin’, xmax’, ymin’, ymax’)}

(x’,y’)

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Simultaneous Localization & Navigation

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Communication of Navigation

N3

N8N6

N12

N15N2

Event Packets

1 15 12 6 8 2 3 6

Event Node’s traversed No of nodes

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Communication of Navigation

N3

N8N6

N12

N15N2

Navigation Request packet: broadcast to its one hop neighbor

Location Packet: location of the mobile robot

Combined

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Communication of Navigation

N3

N8N6

N12

N15N2

Navigation Packets: the acknowledgement packet that contains the bounding box

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Mobile Robot Navigation in Sensor Networks – situation 1

N9

N3

N2

N8

Navigation Packet

A random walk strategy is adopted

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Mobile Robot Navigation in Sensor Networks – situation 1

N9

N3

N2

N8N1

N7

N1, N9, N3, N7

N2 is neighbor of N9 and N3

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Mobile Robot Navigation in Sensor Networks – situation 1

N9

N3

N2

N8N1

N7

The robot always moves along the longer side of the bounding box

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Mobile Robot Navigation in Sensor Networks – situation 1

N9

N3

N2

N8N1

N7

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Mobile Robot Navigation in Sensor Networks – situation 1

N9

N3

N2

N8N1

N7

If the robot realizes that it has lost communication with the sensor node, it hence returns to a previous location

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Mobile Robot Navigation in Sensor Networks – situation 2

N3

N9

N10

N8

N2

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The robot navigation algorithm

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Simulation

• Using ns-2 and matlabUsing ns-2 and matlab• Network topology: 1000 * 1000Network topology: 1000 * 1000• Random distribution of nodesRandom distribution of nodes• Communication range: 40mCommunication range: 40m• The number of sensor nodes: 100The number of sensor nodes: 100

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Simulation

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Simulation – navigation path taken by the mobile robot

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Simulation

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Conclusions

• Navigating the mobile robot using sensor Navigating the mobile robot using sensor nodes that are not localized in an event nodes that are not localized in an event driven network, which in turn get localized driven network, which in turn get localized as the robot is navigatedas the robot is navigated

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Thank you!!