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• 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