3d navigation and localization

WELCOME

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SEMINAR ON

Atmospheric Pressure-Aware

Seamless 3-D Localization and

Navigation for Mobile Internet

DevicesPRASHOB N PAVANANROLL NO : 09S7 ECE

Dept. of ECE

SEMINAR GUIDEMs NIMITHA

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CONTENTS• INTRODUCTION

• TECHNIQUES USED FOR LOCALIZATION AND NAVIGATION

• CURRENTLY USED METHODS

• ADVANTAGE OVER OTHERS

• BLOCK DIAGRAM

• ALTITUDE DETERMINATION

• ADDITIONAL HARDWARE

• IMPROVED ACCURACY OF 2D LOCALIZATION

• 2D LOCALIZATION ERRORS

• ERROR REDUCTION USING 3D AUGMENTED MODEL

• HOW THE SEAMLESS 3D LOCALIZATION WORKS

• APPLICATIONS

• CONCLUSION

• REFERENCE

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Atmospheric Pressure-Aware Seamless 3-D Localization and Navigation for Mobile Internet Devices

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INTRODUCTION

• Advances in Wireless cellular networks

• Provide bandwidth for mobile to access the internet

• In addition

– More powerful processor

– Sensors

• Enables Smartphone for several services like

– User current location

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-LBS (Location Based Service)

-Both indoor and outdoor navigation,

Utilizing GPS(Global Positioning System)

o Outdoor-strong GPS signals

o Indoor –weak GPS signals

-RSS (Received Signal Strength) based

localization

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Fig 1(a) : Satellite used for GPS


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Continues…..

TECHNIQUES USED FOR LOCALIZATION AND NAVIGATION

• Traditional triangulation localization

• Using RADAR (Radio Detection And Ranging)

• GPS

• WIFI Localization

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Figure 1.1 showing GPS navigation


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CURRENTLY USED LOCALIZATIONMETHODS

• Designed for two-dimensional (2-D) conditions

• No altitude information

• Less accuracy

• Not possible for localization and navigation in multi-storied

buildings and navigation around the mountain

• 3D localization based on RFID ( requires more computing

capability)

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ADVANTAGES OVER OTHERS

• Provides accurate altitude information

• Improves the accuracy of indoor RSS based localization using

the altitude information

• Provides seamless 3-D localization and navigation Service

across indoor and outdoor environments

• Uses atmospheric pressure for the altitude determination

• Possible with all android smart phones which uses an

application software for downloading the maps

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BLOCK DIAGRAM

Fig. 1 : Seamless 3-D localization and navigation system framework

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• IN OUTDOOR ENVIRONMENTS• Such as mountains

• IN INDOOR ENVIRONMENTS• Buildings have different layouts on different floors

Figure 1.3 : showing indoor and outdoor navigation

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Fig 1.2 : Mountains


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Fig. 2 :Navigation in a multi-story building

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p2

p1

ALTITUDE DETERMINATION

where,

H – Altitude

P - Measured atmospheric pressure

To - Temperature.

dT /dH - Temperature gradient with the altitude

Po - Standard atmospheric pressure

g – Acceleration of gravity

R - Gas constant.

])/(1).[//( /)./(

00

gRdHdTPPdHdTTH

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By substituting values

Equation changes to

i e; dT /dH =−6.5 K/km

Po =101325 Pa

g = 9.82 m/s2

R=287.052 m2 /(s2∙K)

])101325/(1).[/5.6/( 19.0

0 PaPkmKTH

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• Measured pressure -used to calculate the altitude

• Pressure is measured using pressure sensor

• Height error much less than 0.5 m which is

enough to specify the floor

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Continues…..

ADDITIONAL HARDWARE

Fig. 3 : Atmospheric pressure sensor and communication module

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• Some smart phones have an integrated atmospheric pressure sensor

Or

• Attached through a blue tooth transceiver

• It also uses

• Microcontroller

• Battery

• Power management unit

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IMPROVED ACCURACY OF INDOOR 2-DLOCALIZATION METHOD

• Calculation of distance between sender and receiver is

based on RSS (received signal strength)

• Attenuation Happens during transmission

• RSS is related to distance

• As the distance between the anchor nodes increases the

signal strength decreases

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• Distance can be calculated as

where ,

q - Measured RSS

d - Distance

Q -RSS at a distance of one meter (remains constant)

r - Path loss exponent

E - Random variable

EdrQq lg10

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• E has little effect and can be omitted

Thus,

• It can be used to calculate d from q and r

• d is used in 2-D localization to calculate the location

)10/(10 rqQd

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2-D LOCATION SYSTEM ERRORS

• A multi-story building may have many Wi Fi-APs

• It is deployed on different floors

• The AP’s on the different floors are described in a 3D

coordinate system

• It convert the 3-D coordinates to 2-D coordinates by

ignoring the Altitudes

• 2-D localization - cause a localization error

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Fig. 4 : Position relationships between the user and the APs

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Attenuation by the floor

Device receives the attenuated signal

The L is larger than the true distance

• RSS will not be accurate

• Received wireless signal is attenuated by the floor slab

• It is mainly concrete and thicker than the walls

• L is larger than the true distance between the user and AP3

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FIG:WAP54G

Continues….


Fig 4.3 : Indoor navigation using software Fig 4.3(a) : Indoor navigation

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• A better approach - Real 3-D Coordinate System

– It is used to describe the locations of the APs and the user

– Complex

• An alternative approach

– Augmented 3-D model

• Movement on the stairs is neglected

– Floor number is enough to describe the user altitude

• L′ is the true distance value ( Fig 4)Dept. of ECE


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REDUCING ERRORS USING AUGMENTED 3D MODEL

• C is added to account for the signal attenuation by the floor slab and for the AP on the 2nd floor and user on the 1st;

• Compensation C depends on

– Floor thickness

– Material

• Approximate d to L

• If AP is on the floor 3 and the user on the floor 1 then the C doubles

)10/)((10 rcqQd

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• After considering the Signal Strength Attenuation

• L can be calculated

• L′ can be calculated using the Pythagorean theorem

where H - Distance between neighbouring floorsL′ - Projection value L - Distance

• Improves the localization method accuracy

22' HLL

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STEPS OF LOCALIZATION METHOD

le Map APIs

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• Step 1: check the APs that can be identified to find which APs are on the same floor as the user and which APs are on the different floors

• Step2:calculate the distance from each AP to the user.

The distances between the AP s on the different floor and user are found

• Utilize the traditional triangulation localization method to calculate the location

BRIEF IDEA OF TRIANGULATION

Outdoor navigation software based on the Google Map APIs

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AP 1 AP 2

USER OR OBJECT

;

HOW SEAMLESS 3D NAVIGATION SYSTEM WORKS


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Consider an office building with 4 floors:

1. In outdoor environments ,uses GPS transceiver and the atmospheric pressure sensor to calculate 3D location

2. Indoor 3D localization uses 20 wi fi AP’ s to serve as anchor nodes

3. The smart phone automatically calculates the indoor location based on RSS from Wi fi AP’ s

4. The Application Programming Interfaces of Google updates the map of the current location

5. When user enters the building , the software downloads the location information for each WiFi AP in the building ,including the horizontal location and floor number ,map of each floor , altitude, the distance between floors and compensation C for each floor

CONTINUED……


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PRESSURE DETERMINATION

• In certain smart phones have the integrated pressure sensor ,

temperature sensor and also humidity sensor

• The software running in the smart phone uses the pressure

value to get the altitude information in real time

• The atmospheric pressure decreases as the altitude increases

and vice versa

• The altitude or atmospheric pressure can be used to

determine the floor number

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Fig: 7 Altitude determined by the pressure sensor

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Fig 7.1: Altitude vs Pressure Fig 7.2: Atmospheric Pressure

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APPLICATIONS

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•Used for navigation inside a large shopping mall•Helps in easy navigation in hilly areas•Can keep the track of the user•Helps for the real time measurement and monitoring of pressure•Helps to identify easily the location based services

Figure

CONCLUSIONS

• Seamless 3-D localization and Navigation System uses

Atmospheric Pressure Sensor

• Provide better guidance indoors or outdoors

– Including multi-story buildings or high mountains(on a map

on the user’s device)

• Accuracy

– more accurate than the traditional 2-D localization

method

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REFERENCES

• Bahl P, Padmanabhan : An in-building RF-based user locationand tracking system

• Chintalapudi K, Padmanabha I A, Padmanabhan V N. Indoorlocalization without the plain

• Youssef M, Agrawala A, The Horus WLAN locationdetermination system

• www.wikipedia.com

• ieeexplore.ieee.org

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Thank you……………

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3d navigation and localization

Education

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