Slide 1

AUTOMOTIVE NAVIGATION SYSTEM

Contents

Navigation system: Introduction

Navigation system Example

History

GPS

Navigation Modes

Application of Navigation

AboutAutomotive Navigation System

Automotive: This refers to automation in Automobiles

Navigation: Positioning & Locating...

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

Example: Navigation System

Maptech Navigator

12 LCD display

Touch screen

GPS navigation

Operational data

Navigation In Automobile So Far.

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

GPS 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

Three Segments of the GPS

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

User Segment

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

The receiver performs following tasks:

Selecting one or more satellites

Acquiring GPS signals

Measuring and tracking

Recovering navigation data

User Segment

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, steps 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)

GPS Signals

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.

Four Primary Functions of GPS

GPS Position

By knowing how far one is from three satellites one can ideally find their 3D coordinates

Navigation Modes

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

XTE (CDI)

N (0000)

(00)

N

Desired Track (DTK) (x)

Active Leg

Distance to Waypoint

Bearing (X0)

Present Location

Speed Over Ground (SOG)

Tracking (TRK) (x)

Active GOTO Waypoint

GPS Navigation Terminology

Course Made Good (CMG)

(CMG) (x)

Active From Waypoint

KIWI-W consortium

Whats a Car Navigation System

CD or DVD Drive

TFT display

Remote controller

CPU

System BUS

Decorder

User Interface

Audio LSI

Graphic

Renderer

SDRAM

Flash ROM

SDRAM

Touch panel

Main Unit

Data Disc

Speaker

GPS

Receiver

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

Waypoint

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.

Active Leg

N

GPS Navigation: On the Ground

Planning a Navigation Route

Start

= Waypoints

Application of Navigation

Car Navigation

Dynamic Vehicle Routing

Tracking Rental Cars

Monitoring High Risk Auto Loans

Airline safety