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Car navigation system device

At its core, a car navigation system is a personal computer with all its attributes: motherboard, central processing unit, RAM, read-only memory, hard disk, input and output devices, drives for connecting external data sources. For more references, check out: car navigation systems

 

A feature of the car navigator device is the presence of a navigation processor (GPS receiver chipset). In a number of navigator designs, the navigation processor is combined with the central processor. In addition to the listed elements, a GPRS module, Bluetooth, a radio receiver, and other components can be included in the car navigation system.

The antenna provides reception of signals from navigation satellites. The standard navigation system uses an external antenna that is installed on the roof of the car. The mobile navigator, like a smartphone, has a built-in antenna.

 

For input and output of information, a touchscreen display is used, which is characterized by speed, multifunctionality and low power consumption. In a standard navigation system, a projection display can be used to display information .

 

The standard navigation system is powered by the vehicle's on-board network. The mobile navigator is powered by its own battery. The battery is also charged from the on-board network.

 

The car navigation system software includes an operating system, a navigation program, and other applications (office applications, a multimedia player, games, e-book readers, etc.).

 

Functions of the car navigation system

The modern car navigator has many functions, the main ones of which are:

position determination;

destination entry;

route calculation;

escort along the route.

Positioning (positioning) of the vehicle is carried out by signals from navigation satellites. In order to determine the position (latitude and longitude) of the car on the ground, you need to receive signals from at least 3 satellites. The signal from the 4th satellite also allows you to also determine the altitude above sea level. When receiving signals, the GPS receiver calculates the distance to each satellite, based on which the spatial coordinates of the vehicle are determined.

 

There are two satellite navigation systems in the world: the American Navstar GPS ( global positioning system ) and the Russian GLONASS ( global navigation satellite system ). The GLONASS system lags slightly behind GPS in terms of the number of satellites and positioning accuracy. At present, the positioning accuracy of the GPS system is 2-4 m, GLONASS - 3-6 m. The greatest accuracy (2-3 m) is provided by the joint use of GPS and GLONASS, which is implemented in a number of mobile navigators.

 

Entering a destination in the navigation system is carried out in several ways: by address, by name (points of interest, POI), by coordinates and directly by a point on the map. In a number of standard and mobile navigation systems, voice input of the destination is implemented.

 

After entering the destination, the system calculates the route taking into account many factors (one-way streets, bridges, dead ends, etc.). A number of standard navigation systems offer several route options, calculated according to various criteria (distance, time, money). For example, a shorter route would be as short as possible and would ignore speed limits.

 

But all these routes do not take into account the current situation on the road (traffic jams, accidents, repairs, etc.). Therefore, the greatest demand among motorists is for navigation systems that offer dynamic route calculation taking into account the traffic situation. Information about the traffic situation in real time can be transmitted in two ways: by radio and the Internet.

 

TMC (Traffic Message Channel) has been built on radio communication. Information is transmitted over the TMC channel in the form of coded signals. In Russia, the traffic channel is underdeveloped. TMC is used in standard navigation systems of Volvo, Land Rover, Honda and mobile navigators Alpine, Garmin.

 

Guidance along the route is provided using visual and voice directions. Directions are issued sequentially from intersection to intersection. In different navigation programs, the route guidance function is implemented in approximately the same way, somewhere a little better, somewhere a little worse. There are also major differences. For example, in the Progorod navigation program, the Junction View service works, which, when approaching intersections and complex interchanges, offers a realistic picture-hint indicating the direction of travel.