6. •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
7. •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
8. Space Segment
User Segment
Control Segment
Ground
Antennas
Master Station Monitor Stations
9. 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.
11. •It consists of receivers that decode the signals from
the satellites.
•The receiver performs following tasks:
oSelecting one or more satellites
oAcquiring GPS signals
oMeasuring and tracking
oRecovering navigation data
12. •There are two services SPS and PPS
SPS - The Standard Positioning Service
PPS - The Precise Position Service
13. HOW GPS WORKS?
GPS works in 5 Step, step’s are as follows...
TRIANGULATION
MEASURING DISTANCE
GETTING PERFECT TIMING
SATELLITES POSITION
DETERMINING A POSITION
14. 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)
15.
16. 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
17. • Position and coordinates.
• The distance and direction between any two
waypoints,
or a position and a waypoint.
• Travel progress reports.
• Accurate time measurement.
18. • By knowing how far one is from three satellites
one can ideally find their 3D coordinates
19. • 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
20. Active GOTO
Waypoint
N
(0000)
Desired Track
(DTK) (xº)
(CMG) (xº) N (00)
Tracking (TRK) (xº)
Active Course Made Good (CMG)
Present
From
Location
Waypoint
21. What’s a Car Navigation
GPS satellite System
GPS
Receiver
System BUS
SDRAM
Flash ROM TFT display
CPU
Graphic
Renderer
SDRAM
Touch
panel
User Interface
Decorder Audio LSI
Remote
controller
Speaker
Main Unit
CD or DVD Drive Data Disc
KIWI-W consortium
22. • 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
