• Navigation system: Introduction

• Navigation system Example

• History

•GPS

•NAVIGATION MODES

•APPLICATION OF NAVIGATION

•Automotive: This refers to automation in

Automobiles …

•Navigation: Positioning & Locating...

•System: Combination of all i/p-o/p devices

Maptech

Navigator

12” LCD display

Touch screen

GPS navigation

Operational data

•Introduced in 1977 with electronic compass

• In 1995 Mitsubishi Electric introduced an original

route-guidance system in 1995.

•Uses a 32-bit RISC processor, achieving the fastest

route-calculating performance

Now Automotive navigation system uses the

GPS(Global Positioning System) system

•The Global Positioning System (GPS) is a worldwide

radio-navigation system.

•provide 24-hour three-dimensional position, velocity,

and time information

•The GPS is comprised of three segments

Space Segment: the constellation of satellites

Control Segment: control the satellites

User Segment: users with receivers

Control Segment

Space Segment

User Segment

Monitor Stations

GroundAntennas

Master Station

SPACE SEGMENT

• 24 GPS space vehicles(SVs).

• Satellites orbit the earth in 12 hrs.

• 6 orbital planes inclined at 55 degrees with the equator.

• This constellation provides 5 to 8 SVs from any point on the earth.

CONTROL SEGMENT

•It consists of receivers that decode the signals from the satellites.

•The receiver performs following tasks:oSelecting one or more satellitesoAcquiring GPS signalsoMeasuring and trackingoRecovering navigation data

•There are two services SPS and PPS

SPS - The Standard Positioning Service

PPS - The Precise Position Service

HOW GPS WORKS?GPS works in 5 Step, step’s are as follows...

TRIANGULATION

MEASURING DISTANCE

GETTING PERFECT TIMING

SATELLITES POSITION

DETERMINING A POSITION

GPS TRANSMITTED SIGNAL

• Two signals are transmitted on carriers:

L1 = 1575.42 MHz

L2 = 1227.60 MHz

• Modulation used is Direct Sequence Spread

Spectrum

(code division multiple access - CDMA)

SPREAD SPECTRUM

• Spread Spectrum is used because

- resistance to jamming

- masks the transmissions

- resist multipath effects

- multiple access

• All 24 GPS satellites transmit on the same two

frequencies BUT use a different ID sequence

• Position and coordinates.

• The distance and direction between any two

waypoints,

or a position and a waypoint.

• Travel progress reports.

• Accurate time measurement.

• By knowing how far one is from three satellites

one can ideally find their 3D coordinates

• 3D Navigation

• At least 4 satellites

• Computes latitude, longitude,altitude and time

• 2D Navigation

• Less than 4 satellites or fixed altitude is given

• DGPS Navigation

• Differential corrections are available through

the auxiliary serial port

N(0000)

(00)N

Desired Track

(DTK) (xº)

Present Location

Tracking (TRK) (xº)

Active GOTO Waypoint

Course Made Good (CMG)

(CMG) (xº)

Active From Waypoint

KIWI-W consortium

What’s a Car Navigation System

CD or DVD Drive

TFT display

Remote

controller

CPU

System BUS

Decorder

User Interface

Audio LSI

GraphicRenderer

SDRAM

Flash ROM

SDRAM

Touchpanel

Main Unit

Data Disc

Speaker

GPSReceiver

GPS satellite

• A waypoint is starting or end point

• Either a saved position fix or user entered

• It can be created for any remote point on earth.

• Unchanged until edit by user

Active GOTO Waypoint

Bearing =

Course Over Ground (COG) =Cross Track Error (XTE) =

Location Where GOTO Was Executed

Bearing = 650 COG = 50 XTE = 1/2 mi.

Bearing = 780 COG = 3500 XTE = 1/3 mi.

Bearing = 400 COG = 1040 XTE = 1/4 mi.

N

Start= Waypoints

APPLICATION OF NAVIGATION

•Car Navigation

•Dynamic Vehicle Routing

•Tracking Rental Cars

•Monitoring High Risk Auto Loans

•Airline safety