navigation applications

7/26/2019 Navigation applications

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Navigation applications

Academic Year 2007/08

Master of Science in Computer Engineering,

Environmental and Land Planning Engineering


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Car navigation


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Car navigation

It is possible to distinguish

the two lines of march

Train path reconstruction(different accuracy)


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Car navigationGPS 597 - eBonTek

BluTooth

connection

TomTom portable car navigator

Palmtop PC

GIS (es. ArcPad)

WebGIS (map server)


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Traffic controlIn addition to the navigation of the single vehicle, the navigation

information can be exploited to control the car traffic (and ingeneral the road transportation, ITS).

Interdisciplinary subject:

numerical cartography (GIS) telematics

operative research (to optimize paths, etc.)


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Pedestriannavigation

Conventional GPS only used

for OUTDOOR applications

The INDOOR use of GPS

(when it works), or in the

presence of many obstacles,

does not assure a sufficient

accuracy.

Auxilary sensors are needed


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RFID

It is a presence/transit detector. Main advantages as compared to

bar codes:

it can be detected even if it isnot visible

identification and check are

done in 10/100 of seconds

RFID scanner

RFID tag


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Pseudolites

The PSEUDOLITE (pseudo-satellite) is a GPS transmitter that is installed on

ground in a stable way.

The signal emitted by pseudolites emulates the one emitted by satellites, thus

allowing an accurate and reliable localization in difficult environments, suchas urban canyons or indoor environments.


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Geodetic navigation

The goal of geodetic navigation is NOT the navigationitself (position, velocity and attitude of a vehicle)

BUT the vehicle is used as a moving geodetic platform forother sensors, which are then geo-referenced.

The real-time processingis sometimes useful, but it is notessential as in the case of vehicle control.

Thea-posteriori processingallows to compute the optimal

trajectory.


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Mobile mapping

Multi-sensor systems that lodge (integrate) on a singleplatform a navigation/positioning system with various

data-acquisition systems

Structural components

Positioning system: GPS, Inertial Unit, Odometer, etc.

Sensors: cameras (B/W, RGB, IR); laser scanner; sensors to

measure the pollution level, the resistance of road pavement, etc.

Systems for data acquisition, storage and synchronization.

navigation

sensors

image/signal

sensors

mobile platform

GISdata

digital

mapspro

ducts

images,videos


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GPS / INS

Mobile mapping

Basically it is a revolution

counter to compute the

covered distance

Odometer:


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Mobile mapping


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Mobile mapping

City navigation:

- road cadastre, large-scale cartography

- structure localization / street furniture / etc.

Pavement control

2007 Applanix Corp., All Rights Reserved


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Mobile mapping

Railway applications: tunnel control, level crossing check, railway traffic

management, etc.

Optical system

for rail survey



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Mobile mapping

Marine applications: bathymetry, pipe control, oil explorations

Bathymetry obtained by

sonar (Los Angeles)



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Mobile mapping

Aircraft applications: laser scanning (LIDAR), aerial photogrammetry,radar altimetry, SAR


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LIDAR

It is a distance-meter system mounted on an airplane/helicopter or on aground vehicle or placed in a motionless location.

Typically, mobile mapping

by LIDAR is referred only to

surveys on ground level;

however its principle can be

applied in general sense.


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LIDAR

Multiple reflection

For a flying height of the order of 800 m,

the vertical accuracy is about of 15 cm,

while in planimetry it is about 30 cm.

It can be used for

- DTM / DSM separation

- recognition of objects on ground


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Earths gravitation field

determination from satellite

A satellite orbiting the Earth can be considered as aproof-mass

under the action of the Earths gravitational field.

If the satellite orbit is known, from this orbit it is possible to derive

the Earths gravitational potential.Problems:

the satellite can be tracked from ground for short time-periods

on board GPS for orbit determination

the effect of the gravity is more significant at low altitude, where

the atmospheric drag is higher.

on board accelerometers to measure friction forces


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Earths gravitation field

determination from satelliteWith the development of GPS receivers dedicated to geodetic satellites

and of accelerometers with very high precision (~10-11

m/s2

), threesatellite missions have been designed: CHAMP / GRACE / GOCE


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Navigation and guidance

Geodetic navigation positioning and orientation of a sensor

on board a moving vehicle

Classic navigation real time control of the trajectory andvehicle guidance

Military aviation:

e.g. missile guidance

Civil aviation:

e.g. automatic pilot


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Navigation and robotics

The autonomous navigation is closely related to robotics, in the

sense that, apart from positioning and real-time guidance, concepts

of artificial intelligence (e.g. computer vision) and mechanical

engineering are required.

The Grand Challenge is a competition organized by

Darpa (Defense Advanced Research Projects Agency)among various research centres and universities for the

development of unmanned vehicles.

The navigation of the winner

vehicle was based on six laser-scanner (others were based on

digital cameras), GPS systems,

odometers, etc.

Stanford Volkswagen Tuareg Stanley


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Navigation and robotics

A project has been studied for the development of a navigation

software for an automatic lawn-mower for a golf course.

navigation applications

Documents