Automotive navigation system

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A taxi in Kyoto, equipped with GPS navigation system
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A taxi in Kyoto, equipped with GPS navigation system

An automotive navigation system is a satellite navigation system designed for use in automobiles. Unlike other GPS systems, these use position data to locate the user on a road in the unit's map database. Using the road database, the unit can give directions to other locations along roads also in its database. Dead reckoning using distance data from sensors attached to the drivetrain and a gyroscope can be used for greater reliability, as GPS signal loss and/or multipath can occur due to urban canyons or tunnels.

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[edit] History

Honda claims[1] to have created the first navigation system starting in 1983, and culminating with general availability in the 1990 Acura Legend. This analog system used an accelerometer to judge location, as the GPS system was not yet generally available.

Pioneer claims[2] to be the first with a GPS-based auto navigation system, in 1990.

Magellan, a GPS navigation system manufacturer, claims[3] to have created the first GPS-based vehicle navigation system in the U.S in 1995

[edit] Visualization

Navigation systems use a combination of:

  • top view for the map
  • top view for the map with the map rotating like the automobile
  • bird's-eye view for the map or the next curve
  • linear gauge for distance, which is redundant if a rotating map is used
  • numbers for distance

[edit] Alternatives

Mobile phones equipped with GPS capabilities may be used as an alternative to an automotive navigation system. One such example is marketed by Verizon Wireless in the United States, and is called "VZ Navigator". The system uses gpsOne technology to determine a person's location, and then uses the mobile phone's digital connection to download maps and calculate automobile routes.

[edit] Road database

[edit] Contents

The road database is a vector map of some area of interest. Street names or numbers and house numbers are encoded as geographic coordinates so that the user can find some desired destination by street address. Points of interest will also be stored with their geographic coordinates.

Contents can be produced by the user base as their cars drive along existing streets and communicating via the internet, yielding a free and up to date map.

[edit] Format

Formats are uniformly proprietary; there is no industry standard for satellite navigation maps. The map vendors Tele Atlas and NAVTEQ create the base map in a standard format GDF but each electronics manufacturer compiles it in an optimised, and usually proprietary format. GDF is not a CD standard for car navigation systems. GDF is used and converted onto the CD-ROM in the internal format of the navigation system.

[edit] Media

The road database may be stored in solid state read-only memory (ROM), optical media (CD or DVD), solid state flash memory, magnetic media (hard disk), or a combination. A common scheme is to have a base map permanently stored in ROM which can be augmented with detailed information for a region the user is interested in. A ROM is always programmed at the factory; the other media may be preprogrammed, downloaded from a CD or DVD via a computer or wireless connection (bluetooth, Wi-Fi) or directly used utilizing a card reader.

[edit] Other functions

  • Golf Carts may have integrated GPS units tailored to specific golf courses, providing interactive course maps and live readings of distance measurements to the green.
  • Many systems can give information on nearby POI's (Points of interest) such as restaurants, cash machines and gas stations.
  • Some newer systems can not only give precise driving directions; they can also receive and display information on traffic congestion and suggest alternate routes. This may use either TMC, which delivers coded traffic information using RDS or satellite radio, or an Internet link to a provider's server using technology such as GPRS through the user's mobile phone.
  • The color LCD screens on some automotive navigation systems can also be used to display television broadcasts or DVD movies.
  • A few systems integrate with mobile phones for handsfree talking and SMS messaging.
  • GPS replaces the radio-dispatch of some taxis in Taiwan and Singapore. A central computer tracks all vehicles in the fleet/network, and automatically dispatches the closest the cab within proximity of the customer's location to answer the call. To order a cab, the customer can either talk to an attendant or enter a registered location code for systematic service. The driver would enter an ETA (estimated arrival time) on the computer - which is relayed to the caller by a prerecorded message - at which point a confirmation can be made to accept or reject the cab.
  • Advanced car security systems can relay the vehicle's location via cellular phone services in case of loss or theft.
  • Some navigation devices (map software) also store the location of known speed traps on its map database, and can alert the driver in much the same way as a radar detector as he approaches a speed trap. GPS may also be integrated into actual radar detection devices to enhance accuracy, and in some cases, implement a logic system where the system only alerts if the driver is travelling above posted speed limits.

[edit] Kits

Automotive navigations systems generally includes:

[edit] Example Systems

[edit] See also

[edit] External links

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