That the navigation system in the car. Car navigation systems

"And there is a navigator!". This famous advertising slogan, representing the navigation system by one of the main advantages of the modern car, is partly faithful. Over the past few years, a car navigator from an expensive toy has become a reliable driver assistant.

The car navigation system is designed to determine the position of the vehicle, selecting and maintaining the movement route. The first car navigator was presented in 1981 by Alpine.

There are several types of automotive navigation systems: regular, mobile, as well as navigation software Laptop computers and smartphones. Listed types of navigation systems have their advantages and disadvantages. They differ in design, realized functions, price.

The regular navigation system is installed at the car factory and, as a rule, is part of the multimedia system. Compatible navigation systems of other manufacturers can be installed in a regular place.

The mobile navigation system is a portable autonomous navigation device that is purchased separately and installed on the windshield or dashboard. Under the term "car navigator" Mobile navigation system is usually understood.

As a car navigator, a laptop computer, smartphone and even ordinary mobile phone models can be used if the corresponding navigation programs are installed.

Automotive Navigation System Device

In essence, the automotive navigation system is personal computer With all his attributes: motherboard, central processor, rAM, permanent memory, hard disk, information input and output devices, connectivity drives external sources data.

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

Receiving signals from navigation satellites provides an antenna. The standard navigation system uses exterior antennawhich is installed on the roof of the car. Mobile navigator, like a smartphone, is equipped with a built-in antenna.

To enter and output information applied touchscreenwhich is characterized by speed, multifunction and low power consumption. A projection display can be used in the standard navigation system.

Food is a regular navigation system from the on-board network of the car. Mobile navigator isted from its own battery. Charging the battery is also made from the on-board network.

The automotive navigation system software includes an operating system, navigation program, other application programs (office applications, multimedia player, games, reading programs electronic books and etc.).

The operating system connects the hardware of the navigator ("iron" with an application program. As operating system are used windows programs CE, Windows Mobile, Android, iOS, etc.

The functional basis of the navigation system is navigation program. In automotive navigation systems, a variety of navigation programs that differ from each other interface, functionality, the degree of speed and unification is used. Fortial navigators use mainly their own development of navigation programs.

For mobile navigators, PDAs and smartphones, domestic navigation programs of Navitel, autospaulite, cityGuide, ranging and a number of others have been created. From foreign programs it is necessary to mark the popular IGO program. The IGO program is also used in the staff navigation systems of the Korean car Hyundai, Kia, SsangYong. In mobile navigators, PDAs, smartphones, several navigation programs can be installed, which significantly expands the capabilities of the navigation system.

The navigation program is built on electronic map. Automotive navigators use basically vector electronic cards that support routing. The vector map includes many objects with their geographic coordinates.

If the plans move by off-road car, then you need a navigation program with raster card. Unlike vector raster card It is an image of the area (transferred paper card or satellite photography), tied to geographic coordinates.

The leading world electronic card developers are Teleatlas and Navteq, but the cards from these manufacturers still have insufficient coverage of the territory of Russia. For this reason, many Russian navigation program developers (Navitel, Hrought, Citigid) use their own electronic cards.

Functions of the automotive navigation system

In the modern car navigator, many functions are implemented, the main of which are:

• definition of position;
• entering destination;
• calculation of the route;
• maintenance on the route.

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

There are two satellite navigation systems in the world: American Navstar GPS. (global positioning system) And Russian GLONASS (global Navigation Satellite System). The GLONASS system is slightly lagging behind the GPS by the number of satellites and the accuracy of determining the position. Currently, the positioning accuracy of the GPS system is 2-4 m, GLONASS - 3-6 m. The greatest accuracy (2-3 m) gives sharing GPS and GLONASS, which is implemented in a number of mobile navigators.

Under certain conditions (movement in the city, tunnel), the receipt of signals from satellites becomes problematic. In a regular navigation system for positioning under a bad signal, the angular velocity sensors of the ABS wheels and the longitudinal and transverse acceleration sensors of the ESP system are used. With the help of sensors, the speed and direction of movement is estimated.

IN mobile systems This feature runs the navigation program. When the signal is lost, the system believes that the car moves along a given route at constant speed.

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

After entering the destination, the system produces calculation of the route Taking into account the set of factors (streets with one-sided movement, bridges, deadlocks, etc.). In a number of full-time navigation systems, several options for a route calculated on various criteria (distance, time, money) are offered. For example, a short route will consist of possible shorter sections and not take into account speed limits. Quick route is based on the class of the road (highway, federal route, urban street) and speed limits on these roads. The economical route takes into account the distance and time. Time, while preference is given.

But all these routes do not take into account the current situation on the road (traffic jams, accidents, repair, etc.). Therefore, the highest demand for motorists use navigation systems offering dynamic calculation of the route Taking into account the road situation. Real-time traffic information can be transmitted in two ways: radio communications and Internet.

On the radio, the communication channel was built on the TMC Road (Traffic Message Channel). On the TMC channel, the information is transmitted as encoded signals. In Russia, the channel reports about the road situation are not developed enough. TMC is used in the full-time Navigation systems for Volvo cars, Land Rover, Honda and Alpine Mobile Navigators, Garmin.

An alternative to TMC channel is the transfer of information about the traffic situation on the Internet channel. This technology Most mobile navigators, PDAs and smartphones use. From the mobile navigator, the Internet access can be organized in two ways: using the GPRS module and SIM card, through mobile phone via Bluetooth channel.

Information about the road situation comes from different sources of the Internet. Navitel program has its own service "Navitel. Traffic jams". Sitigid navigation program offers its road trip service system. In other programs, the well-known service "Yandex. Traffic jams".

It should be noted that regular navigation systems, as a rule, do not have communication with the Internet, and if they have, this channel is not used to obtain information on the road situation. Exception is newest system RTTI (Real Time Traffic Information) from BMW, built on the basis of cellular communication and receiving information within the TPEG system (Transport Protocol Expert Group).

Maintenance along the route It is implemented using visual and voice instructions. Instructions are issued consistently from the intersection to the intersection. In different navigation programs, the accompaniment function on the route is realized approximately the same, somewhere a little better, somewhere slightly worse. There are also serious differences. For example, in the navigation program, the warring is running the Junction view service, which, when approaching crossroads and complex junctions, offers a realistic tip picture indicating the direction of movement.

Navigator is a useful thing. And, in theory, very comfortable, especially when it is a regular car equipment. But is it really impeccable built-in navigation systems? For example, they are knowingly more expensive than portable navigators, although not a fact that is better in characteristics. And as a rule, the more expensive the car and the prestigious brand, the more blood you need to lay out for your native navigation. Did the navigator of the folk car several times worse than the premium? I decided to find out if I experienced all the machines on a single technique that checks not only the skill of the systems to find an object and lay the route to it.

Where does it lead?

In the world, two supplier of cartographic data: the company "Navtede", USA, and the Dutch "Tel Atlas". Judging by official responses from manufacturers, all dough participants are based on the data of the American developer. However, this does not mean that they have the same coating.

To begin with - a test for knowledge of the native country, consisting of 16 arbitrarily selected settlements, from regional centers to distant villages. All assigned points have submitted only to the "Akura-MDX" navigator. Renault Logan and Subaru-XV found in memory one less. The "Range-Rover" was worse (at a price of 8 million): It navigating only eight points from the list. For one more from Cadillac-SRX (also checked, by the way). Well, yes, it is necessary to shock the owners of such machines with information that there is a village of Swingus on the backyards of the Ryazan region, and in Tambov people live in some Sarymovka.

Interesting tasks and among Moscow streets were found. The address in one of the promsion did not master any navigator: the most diligent only brought to the desired street, and then they were offered to look for the object itself. The path to a residential building through the yard drives of a large quarter was able to pave five experimental. The second half of the "sussanin" schitri, snapped instead of the desired high-rise building, located on the street, and not in the courtyards. It would add an automatic set function help service: From the proposed finish point to the desired house almost a kilometer strictly in a straight line and more than 2.5 km by car! And more than the others surprised "Nissan" and "Cadillac". The editors' building "behind the wheel" was not in their memory - house number 10 in Seliversore Lane. Come visit, show that it exists, and in the city center, in the zone of old building. Does the cards in these cars older than our magazine?

How does it lead?

About cartography. By downloading navigation on your smartphone, you can easily find the most modern version. Update once a quarter - in the order of things. In the cards for standard automotive systems, the year and quarter is also often indicated, but in fact, the adjustment occurs only once a year. Manufacturers have a very popular vague wording "not less than once a year", which actually means the only update for 12 months. But still you need time to adapt cards to a specific brand or model ...

So it turns out that in the machines of 2014 there is no disconnement, open in December 2012. And "terrano", "Logan" and SRX do not know about one of the jumpers in Moscow, launched back in December 2011. In the rush hour, the 250-meter segment is missing in the program until half an hour. Of course, in Moscow, only collecting fines of the structure have time for the reorganization of the movement, and in the cities less the problem of "pruderosh" cartography is not worth it. And yet the deadlines are not happy.

The cost of new cards is not always directly dependent on the status of the brand. For example, "Volvo" and "Volkswagen" updates are free, and Ranj-Rover and Nissan have very expensive.

And further. The exclusion function of paid roads When building a route, which is laid in all navigators, we have yet useless: plots, for the fare for which you need to fork out, glowing on the envy of rabbits, and the speed of updating cards does not sleep for them.

What does it say?

After dense communication with a dozen electronic conductors confidently declare: another person who can make and reproduce competent tips for navigators in Russian. And while everyone is waiting for his coming, I would first deprive the voice of the "Logan" system. Her "eaten" and "eaten" - out of competition in the nomination "This is not said in Russian." Against this background, the turn "Using the Second Congress" is no longer surprising. Kia-Soul suggested "turning into the second street." Subaru with a mysterious accent says "Pribudét". From the speakers of the "X-fifth" instead of "accepting", it is clearly heard to "be taken over", and after the words "immediately turn to the left" immediately, I got into a stupor at all.

There are complaints and to the essence of tips. For example, the voice in Subaru-XV first intrigues: "Get ready after 800 meters ...". And withstanding theatrical pause, adds: "... go straight." Special piquancy is that it was said on an eight-way Kutuzovsky Avenue, to move from which in the darkness is impossible in principle. By the way, in Subaru, there is an original function of choosing a "level of verbia". True, in the "concise" mode, words do not become less, but the border of the prompts is why it is shifted from 100/300 m per 30/80 m, which makes them completely useless.

But the other extreme. In general, the successful system of "Akura" turned out to be unnecessarily a little. She allowed himself not to voice some maneuvers, sometimes forgotten repeating the prompts immediately before the intersection. And once surprised by a strange phrase: "Turn right on the third street," after which it was silent for a long time, considering further instructions to be superfluous.

Many cars communicate with non-jammed phrases, but cuts from individual words. At first, it sounds crook, but such hybrid expressions can be used to it. Some models are able to pronounce not only maneuvers, but also the names of the streets. Subaru and BMW cope with the task of good, but Kia has an incomprehensible set of sounds.

What to press?

You can feed the command to the command in two ways: by pressing the touchscreen display or oncoint the joystick and keys on the panel. Advanced "Bavarian", in addition, understands "on rumor" the names of streets and settlements and even has a touchpad for writing manually input characters. All this works great, although confusion arises with individual symbols: the letter in it is perceived by how e, then how s, and for some reason it strives to replace the nine.

All navigators have a clear and logically constructed menu required (and even excessive places) list of settings, a standard address entry diagram, a Russian-language keyboard. But without several spoons, the tar will not cost. For some reason, Subaru does not have a Russian-speaking keyboard, the Volkswagen system hanglessly freezes when the destination is first launched (this deficiency is already fixed on fresh machines).

Two more stones fly in the garden of premium brands. Entering destination at Kadillaka is not divided into levels (country, city, street), and implemented by one line. As a result, predicative input does not work when the system according to the first entered letters immediately offers possible options. (This is perfectly implemented by all other test participants.) Uncomfortable? Not that word! Included with a hoping touch screen, which also perfectly removes fingerprints, depressing pattern.

Ranj Rover struck by a mediocre schedule, resurrecting school years in memory, when I painted out contour cards with colored pencils. Hands still remember - can, offer to developers their services? The physical dimensions of the screen play not a major role. Part of its area still occupies a different additional information that limits the map size. And the lowest monitor "Nissan" could be done at least 10-inch: the convenience does not add.

WHAT ELSE?

The most modest on functionality is the "terrano" navigator (the same is also in the "Almere"). The only "chip" is not described in the manual: in the file with coordinates of photo and video cameras, there are radars located outside the coating zone, and therefore it can be useful in Europe.

The Logan Navigator keeps in memory information about the speed limit and the traffic strip. Excellent set for the budget system! In more expensive models, prompts appear on the display of the instrument combination, and the top of perfection is the projection of navigation tips on the glass (BMW). There are also original solutions like warning about a small fuel reserve ("Volkswagen" and "Range Rover"): based on the data of the route computer, navigation will automatically offer several closest gas stations. Three-dimensional buildings are drawn on Cadillac maps, Kia and Volvo. True, the first slowly slows down in the maximum resolution mode.

The TMS function (reception on the radio channel of traffic information) is sewn to all navigators, but it only works on Akur, "Volvo" and "Ranj Rove." Trips around the city showed: color "cork" strips on the screen very accurately reflect the situation, but to analyze the information and work the route of the trail is better. "An Englishman" strives to see even from short queues before the traffic light. "Japanese" for some reason incorrectly shows the length of the congestion: even a small tail in reality stretches on the map to the previous intersection. Since the summer it will show the situation on the roads and BMW, but the Bavarians implemented the service via the Internet.

RESULTS Not very pleasant for manufacturers and owners, but demonitive. Good coverage of the territory of Russia - only in three navigators: "Akura", "Renault" and "Subaru". As for Moscow, everyone has gaps; If the systems do not know the omissions of the old regions, when they learn the road to new buildings? By speed updates, mobile navigators leave no chance of built-in.

Given the functionality, you can call the price of only the Loganov system. Tell me about traffic jams, would have become a unconditional leader. But - only in this particular company. After all, the removable box "Garmina" with "Yandex. Corks "even cheaper. And for the set of parameters, I would prefer the Navigator "Akura". By the way, in the related "Hondah" there is the same system.

If I were Sultan

... it would collect the perfect system by borrowing the components from several cars. Cartography - at Akura, voice prompts - Nissan. And would add them to Subarovskaya "voice acting" streets. The menu comes to almost any model, but the graphics are the most beautiful in Kia. As a part of the management of the unambiguous leader - BMW: The choice serves a convenient joystick, touchpad and voice input. It remains to add a cork service in the implementation of "Volvo" and the price as "Renault".

"Nissan Terrano"

Price of the machine with navigation: from 872 700 rubles.

Countries: Russia, Ukraine, Baltic

Cost update: about 14,000 rubles.

+ Clear Voice Tips

- expensive update, modest functionality, low screen

"Renault Logan"

Price of the machine with navigation: from 422,000 rubles.

Management type: touch screen Countries: Russia, Ukraine, Belarus from 16 settlements know: 15 Cost of updates: from 4500 rubles.

Budget option without losing much more expensive staffing systems

+ Pleasant graphics, abundance of additional information, acceptable priceGood coating

- illiterate speech, there is no Russian keyboard with layout of letters alphabetically (only "Computer")

"Kia-Soul"

Price of the machine with navigation: from 989 900 rubles.

Management Type: Touch Screen

Of the 16 settlements know: 11

Cost update: from 450 rubles. *

* Updates from the site of the company "Navitel".

+ Excellent graphics, abundance of additional information, inexpensive update

- pronounced street names to understand impossible

"Subaru-XV"

Price of the machine with navigation: from 1,274,000 rubles.

Management Type: Touch Screen

Countries: Russia, Ukraine, Moldova, Europe

Of the 16 settlements know: 15

Cost update: from 10,000 rubles.

+ A lot of additional information and settings, pronounces the street, good coating

- slows down with a manual scrolling card, only an English keyboard, the navigator does not seem to be native, but installed separately

"Volkswagen Golf"

Price of the machine with navigation: from 915 570 rub.

Management Type: Touch Screen

Countries: Russia, Europe

Of the 16 settlements know: 10

Cost update: free

+ Good voice accompaniment, there is a low-level fuel warning function, free updates

- Winning system won only this year

"Cadillac-SRX"

Price of the machine with navigation: from 2 189 000 rub.

Management Type: Touch Screen

Countries: Russia, Europe

Of the 16 settlements know: 9

Cost update: about 10,000 rubles.

+ Shows traffic jams, visual tips on maneuvers

- Weak for the machine of this class functionality, graphics and coating

"Volvo-hs60"

Price of machine with navigation: from 1 678 700 rubles.

Management Type: Rotating Handle and Keys

Countries: Russia, Ukraine, Belarus, Moldova, Baltic States, Finland

Watch the route on a small phone screen? Mitten with the modest functionality of the navigator? Close the dashboard by the devices? Why, if you can buy a regular navigation multimedia center and enjoy all modern technologies In one case?

The regular navigator for the car is installed in a special compartment on the dashboard and allows:

• put routes;
• listen to music;
• watch photos and video;
• publish online;
• check email;
• work in office programs.

Buy a full-time navigation system - it means to get a device with unlimited functionality created specifically for your car. Most regular navigators run on tablet OS, so you can download any applications. At the same time, it is not necessary to recalculate the route, if someone called you, take care of charging and be distracted by multiple gadgets.

The priority of "track" is the sale of navigation multimedia centers for best prices. We present regular navigators for all popular brands:

• Nissan.
• Toyota.
• Renault.
• Mazda.
• Honda.
• Volkswagen.
• Hyundai.
• Chevrolet.
• Mitsubishi.
• Subaru.
• Citroen
• Skoda.
• Suzuki.
• Peugeot.

Before you buy a regular navigator for your car, read the description and photo of each brand.

Navigation systems (Global Positioning System or GPS - Global Positioning System) are becoming more widely used in Western Europe, USA, Japan. It begins the use of these systems and in countries former countries The Soviet Union, but the development of navigation systems is constrained mainly due to the lack of locality maps.

The main tasks of the navigation system are:

• determining the location of the car currently
• entering the destination with the definition of the optimal route

When choosing a route, 3 options are offered - fast, normal and short. In addition, it is indicated where there are paid roads and features of the movement for each route.

In order to use GPS navigation, you need at least a GPS receiver. But in itself, it is nothing more than a satellite compass that knows its exact coordinates. To link these coordinates with a specific digital location map, you need a more complex device, for example, a GPS navigator with a built-in GPS receiver.

Fig. Navigator

What is a navigator?

GPS-navigators - Devices with a relatively simple software shell, focused mainly on solving navigation tasks and able to work with only one card type provided by the manufacturer.

The calculation of the position of the GPS receiver is carried out on the basis of the pre-known coordinates of the system satellites. It is physically expressed in the fact that the initial data to solve the positioning problem are distances from the object to all the satellites at the moment. For simplification, we assume that all visible satellites are in their orbits in a fixed state.

Turn to geometry

Fig. Object detection by satellites:
a - sphere from one satellite; b - intersection of spheres from two satellites; in - intersection of spheres from three satellites

The remaining point and characterizes the coordinates of the receiver. The distance to satellites (the radii of the described areas) is calculated simply - based on the fixation of the time of the signal to the object and its speed.

To determine the position of satellites in orbit, in addition to the combination of satellites dispersed in stationary orbits, there is a ground control complex. It consists of tracking stations that support constant contact with elements of the orbital grouping. According to the data received, the exact coordinates of artificial satellites are calculated in the control center and through communication stations are transmitted to aircraft. When calculating it is assumed that the speed of signal propagation is equal to the speed of light. Therefore, it is necessary to take into account even accuracy and synchronization of the work of the hourly mechanisms that are equipped with a satellite and receiver, as well as distortions caused by various obstacles to the passage of the information wave. To eliminate errors in the receiver's computer, special algorithms are used, which adjust the time until the receiver location is defined with a predetermined error. The algorithm also takes into account the data received from the fourth, fifth, etc. Satellites, which are located in the "visibility zone" of the receiver.

Note that a full-fledged grouping that will provide the coverage of the entire surface of the globe should include 24 orbital objects, that is, the maximum number of satellite receiver at any point of the Earth - 12 units. However, today the number of existing navigation systems is already 30 units.

The figure shows the structure of the navigation system. The system can exercise navigation, determine the position of the vehicle on the locality map on the configuration path passed, to determine the absolute coordinates using the GPS satellite system. With the help of navigation number, the relative position of the car and the direction of movement according to the information obtained from the wheel speed sensors and azimuth is determined.

The configuration of the site traveled using navigation number is compared with the road configuration applied to the card. Having determined the road on which the car moves, the system finds its current coordinates. A more accurate determination of the coordinates of the car on the map is performed using GPS in latitude and longitude. It is believed that for practical purposes it is enough to know the coordinates of the car with an accuracy of half the quarter, that is, ± 100 meters.

The car navigation system should have in its composition the sensors of the path traveled and the direction of movement.

Sensor traveled path

Sensor traveled path - This is the one or another design of the electron odometer, the information in which comes from the ABS wheel speed sensors. Odometers are inherent in a number of systematic errors that need to be adjusted. These include:

1. The difference in the diameters of the new and worn tire gives an error in determining the distance traveled to 3%.
2. By increasing the diameter of the tire from the centrifugal force for every 40 km / hour of the velocity of the car, the error in determining the distance traveled increases by 0.1 ... 0.7%.
3. Changing tire pressure on 689 kPa increases the error by 0.25 ... 1.1%.

To determine the direction of the car's movement, azimuth sensor is commonly used, wheel speed sensors, gyroscopes.

Fig. Structure of the navigation system

Azimuth sensor

Azimuth sensor (Compass) uses the magnetic field of the Earth and is a ring core 2 of the ferromagnet to which the excitation winding is wound 1st perpendicular to each other two output windings 3 and 4. The sinusoidal voltage is applied to the excitation winding. In the absence of an external magnetic field, the output windings are guided by EMF of mutual induction, also sinusoidal, with zero average. In the presence of a permanent external magnetic field (the magnetic field of the Earth), there is a distortion of the sinusoidal shape of the magnetic flux in the core due to the overlay of the constant component and the voltages of the output windings.

Fig. Geomagnetic azimuth sensor:
1 - excitation winding; 2 - ring core from ferromagnet; 3 - output winding with the x coordinate; 4 - output winding with coordinate y

Wheel rotation sensors

GPS systems use the rotational speed sensors used for ABS. The rotation angle of the car is determined by the difference in the paths passing by the left and right wheels.

Gyroscope

When using a gyroscope, the car's angular velocity is determined and integrated to determine the angle of rotation. In navigation systems used different types gyroscopes. Below, as an example, the use of a gas gyroscope is considered.

Gyro works as follows. The pump creates a gas stream (helium) 2 at a given rate of expiration and directs it through nozzle 15 two heated sensor wires W1 and W2 (Fig.). The angular velocity of the car is determined by changing the resistance of the sensor wire. When the helium flow comes out of the pump nozzle, it gradually expands.

Fig. Gyroscope measuring system (gas flow location when turning)

When the car moves straight, the distribution of speeds is symmetrically relative to the wires, they are cooled equally and at the output of the bridge circuit, part of which are wires, bullet voltage. When turning, the Coriolis force arises, a shifting gas stream, the wires are cooled unevenly, their resistance electric Toku. Different, at the outlet of the bridge circuit, there is a voltage proportional to the angular velocity of the car on the rotation.

Dead reckoning - This is the method of determining the coordinates of the moving object (car, aircraft, vessel, etc.) with respect to the starting point. The sum of the vectors of the distances passed, information about the directions comes from the azimuth sensor or the wheel speed sensor. The figure shows the use of navigation number to determine the coordinates of the object (car).

Fig. Determination of the coordinates of the car by the method of navigation number:
X0, y0 - initial coordinates; Δi - the increment of the current position; θi is an angular position; X, Y - coordinates of the car

The magnetic field is also distorted in tunnels, on metal bridges, when driving along the road trains. The use of wheels rotating speed sensors along with the compass often solves this problem. Wheel rotation speed sensors are not sensitive to such distortions, in practice, the azimuth sensors and wheel speeds complement each other when determining the direction of the vehicle movement.

The navigation number gives a low accuracy of determining the current coordinates of the object. For a car, you have to adjust the coordinates defined by navigation number every 10 ... 15 km. The adjustment will be correct if cars move along the roads that are applied to an electronic card.

Electronic maps

In some navigation systems, mapping information is stored centrally and transmitted to a car by radio channel, but in most cases the navigation system involves the presence of the required database on board the car.

CD-ROM is used to store cartographic and road information in order to compare the configurations of roads and the path traveled, find the optimal route, output of the area map on the display.

In the matrix format, each card element (pixel) corresponds to the X-Y Cartesian coordinates. Matrix cards require a lot of space in the computer's memory or a packet of information and uncomfortable for mathematical operations when laying and tracking the route.

In vector road format, the streets are represented by sequences of sections of the direct, described analytically, intersection - nodes. The nodes are identified by the coordinates - longitude and latter. If the road (street) is not straight, the node is also placed at the break point. Thus, roads (streets) of any configuration are approximated by a set of vectors and nodes.

Fig. Streets and knots on vector map

Available maps or areas of terrain, obtained from airplanes and satellites, are scanned. Then the special software transforms the image first into the matrix, and then into the vector format.

The electronic map carries such information as road numbers, street names, houses of houses between intersections, one-sided or double-sided movement on the street, hotel names, restaurants, etc.

The touch switch on the screen allows you to change the image output mode by selecting the separate or full screen with the direction of the turns, the turning list or information about the congresses from the motorway.

Fig. Plot signs

Orientation on the locality map on the configuration

First, the navigation system determines which of the nearby roads can correspond to the coordinates of a car defined by navigation. Then there is a comparison, the most appropriate road is selected and the coordinates of the car on the map are adjusted. When the car reaches the intersection, the choice of the road is determined by the direction of movement. If the roads at the crossroad look approximately the same, the navigation computer traces them according to the map forward and determines the correlation coefficient for each of the roads with respect to the desired route. The road with the highest correlation coefficient is selected.

Navigation systems allow you to receive information voice controlThat allows you to get the necessary information without breaking away from the road. In total, modern systems recognize up to 1500 words.

For a detailed consideration of the selected section, you can bring it closer or removed to cover a more extensive zone. You can simultaneously display two cards at the same time, one of which shows a more detailed range, and the other gives a wider coverage. If necessary, it is possible to find the nearest hotel, restaurant, refueling, service station, parking place, etc.

Fig. Screen splitting

To explore the route, the driver can perform preview Route.

500 meters to the approaching intersection on the screen automatically displays an enlarged circuit of the junction. As you approach the intersection will sound a voice message, resembling the driver about the upcoming actions. If the driver missed the desired rotation, the system itself adjusts the route.

In case of insufficient information about the location of the destination point, the navigation system can search for postal index, in geographical latitude and longitude, on the map, in crossroads and entry-congresses from the motorway. In memory of the system, information on places that the driver wants to visit again is introduced.

In the event of automotive traffic jams or hindered road traffic on the path of the selected route, the system expects and offers an alternative route.

Select the optimal route

In addition to determining the current coordinates of the car, the navigation system can also issue information that facilitates the choice of the optimal path to the destination. To do this, the navigation computer is considering a road network between the source point and the destination and select the shortest route. An example of the method of determining the shortest path on the map is algorithm Dyacstra (Dijkstra algorithm).

In the Daekstra algorithm, all intersections of the roads are made from the starting point and the shortest paths are calculated before each intersection point. For example, if there is a road network, as in the figure, the search for the intersections will start from the starting point A. First, the intersections of the intersection in and S. distances from the point A to each of the intersections are indicated inside the circles. The intersections E and F are considered, connecting to the point C, for these intersections, the distance from the starting point A. Thirdly is indicated, the intersection of D and E, connected to the point B, in Figure B shows the distance from the start point A to D and E . At the same time, the distance to the point E is indicated through the point C, since it is less than through D (it would be 8). Point D is associated with a point E, and the route through e turns into shorter. The shortest way to D turns out the route A-C-E-D.

Using this algorithm allows you to determine the shortest route to the destination. Having a modern navigation system, the driver may not be afraid to get off the way.

Fig. Algorithm Dyacstra

Further development GPS received in the development of intelligent transport systems (ITS - Intelligent Transportation Systems).

A similar system Extended Floating Car Data-System (XFCD) introduced BMW.

The test was carried out on a special test track in SBC PARK and was intended to demonstrate the capabilities of the system. For example, a car gets on a slippery road. In seconds, the system processes information and warns in real time the next car behind it. The same information at the same time is transmitted to stationary movements, which statistically process the incoming data and send them back to other participants of the movement.

The XFCD Road Situation System will be in the future improved follower of the existing Floating CAR DATA system, which is translated as "data from a moving car". Already today, with the help of FCD cars send their location data at a certain point in time to the central motion console, which compares the received messages with other cars equipped with FCD, in order to recognize road and freelance situations. The XFCD system is capable of recognizing the road situation itself, analyze all available data in the car and transmit processed data to the central remote control. In parallel, the system is capable of warning other cars through the Auto-Auto communicator system in the transmitter zone.

XFCD operates on the basis of the existing navigation system, and its commissioning is only in the download of the program. The introduction of the on-board network allows synchronously to use a whole range of possibilities. In the modern car, the system has access and alignment with many other information blocks of control. It is Middle and Far Light, fog lighting, an environmental thermometer and air conditioning, brakes and a navigation system, rain sensor and a glass washer, as well as other equally important little things. All these mechanisms operate depending on the road situation. So, to lower the ambient temperature, ice or even unexpected appearance of oil on the road section of the car immediately responds with the regulation of the stabilization control system (DSC) and the speed of movement.

Another indisputable advantage of the XFCD system is to transmit messages directly to other cars. Information is transmitted via AD-HOC network to all cars in the nearest surroundings. Each car, depending on the situation, performs the role or sender, or recipient, or transmitter. The advantage of the proven technology Multi-Hopping is indisputable: the AD-HOC-network is organized autonomously, has the necessary range of radius of action and does not require the creation of a special infrastructure.

My first acquaintance with automotive navigation systems occurred a few years ago, when I studied in the penultimate course of the Polytechnic Institute. In those days, a student student was sitting next to me, in the future he received a red diploma, and currently working as a programmer in Sony in New York. This student during lectures on the history of world culture told me about his technical inventionwhich consisted of a computer with an electronic map of the streets, sensors, registering turns and counting the distance traveled by a car, and more couples-troika small measuring instrumentsDesigned to provide input data for a cunning program that calculates the coordinates of the car and its location on the map in the form of a large white point. My neighbor in the party even offered me to combine our efforts and make an experienced sample system to then sell it to the Zaporizhia car plant (it must be assumed to equip the "Zaporozhetsev" with these fixtures). "You want to get from Kharkov to Zelenograd," he said, "and the card will show you where to go and where to rotate." I refused now about this regret, because modern car navigation systems (ANC) are exactly what at one time offered to make my fellow students, with the exception of such a component as GPS (Global Positioning System), which he is at that time I did not know yet. It is symbolic that in the very first issue of GIS Review magazine, released in 1994, the automotive navigation systems are devoted to the whole two news. The first of them read: "Sony Electronics began the spread of the onboard car navigation system GPX-1. It includes a GPS receiver, a five-linked screen and a digital road cartographic system of ETAK on CD-ROM. It can be used when determining the location (navigation) and planning the route. " The second was devoted to signing an agreement between Etak, Tele-Atlas Int. And Robert Bosch GmbH on the joint development of digital maps of the road and street network for Western Europe. In other words, car navigation systems are known for quite some time: ideas about them began to turn in the air, as soon as computers appeared, the dimensions of which allowed them to move them vehiclesSpecific outlines such systems have taken from the occurrence of the global NavStar navigation system, which allowed us to determine the coordinates of any object on the earth's surface with an accuracy of 2 - 3 meters using DGPs.

Europe, Japan, America ...

The Japanese recognize that the concept of the automotive navigation system originated in Europe, from which Japan, despite the obvious progress in this area, lagged down until 1996. At the same time, the United States lagged behind both Europe, and from Japan: while European and Japanese car manufacturers in need equipped their products with automotive navigation systems and competition in both markets was very tough, the Americans occupied a careful position, and OldSmobile was almost the only American company that put on model 88 LSS car navigation system ZEXEL GUIDE-STAR AVL. This is explained by the fact that in America there are a lot of good roads and a relatively small car density, the speed and safety of moving affects almost exclusively traffic and weather conditions - as a result, a surge of interest in road navigation systems in America only in the middle of last year, when it appeared The ability to receive traffic and weather cards for any real-time region in real time for route planning.

By the mid-1990s, the main players of the AnS market were identified with them by European companies Bosch, Philips, Blaupunkt and Japanese Etak, Sony, Alpine and Pioneer. As can be seen from the list, among them there were no firms developing software, GIS companies and giants of automotive, and the first places were taken by traditional car manufacturers (and this provision remains to this day). Thus, car navigation systems were equated to receivers, tape recorders, vacuum cleaners and washing machines. In other words, Ans is a household device, and not the product of the IT industry at all, no matter how surprisingly, this sounds. By the way, in English literature, automobile navigation systems are called either Auto-Pilot System (APS), or Automatic Vehicle Locator (AVL) or Car Navigation System. For some reason, it is not accepted to reduce the latest phrase, although today, according to my observations, it is most used. The need for maps representing the key component of each automotive navigation system, in Europe provided by two groups of companies - European Geographic Technologies (EGT) consortium, which was headed by the American Navigation Technology Corporation, and the Alliance formed by Tele-Atlas and Robert Bosch (later to them The American firm of Japanese origin ETAK joined, as reported by the news two, quoted above). The first group released Philips navigation cards, the second - Bosch. Both worked overtime, struggling to cover as many geographical space of Europe as possible. In those years, BMW installed the Philips Carin navigation system on its cars, and Mercedes - Bosch Auto-Pilot System (on the s-class machine). It was estimated that the use of ANS in Europe saves 50% of the time required to get from point A to point B, especially if these points are located in different countries.

The well-known production of the car machine and the coffee grinder Japan at that time also actively rushed forward. The feature of the development of automotive navigation systems in the country of the rising sun was that these developments were not entirely focused in the hands of private companies, but were maintained by the state. The first swallow of intellectual transport systems (to which the ANS) in Japan became the project "Full-featured Car Management System" (CACS), developed by the Ministry of International Trade and Industry of Japan in the period from 1973 to 1978, was estimated at 73 million . dollars and laid the foundations for further development of such products. At its end, some developments were used by the Ministry of Construction of Japan in the Road Automobile Communication System - RACS project and the country's police to manage traffic and ensure communication between police machines. Later, the results of the work carried out were integrated as part of the "Automotive Information and Communication System" system (VICS), providing the driver about traffic on the roads and the planning optimal route. The system has become available to consumers in April 1996 by that time, Japan had 67 million cars on the roads, and this truly unlimited crowd of potential consumers provoked fierce competition for the place under the sun. Like any competitive struggle, it led to lower prices and the emergence of technical and technological innovations.

Car Navigation System Bosh Blaupunkt Travel Pilot

One of the reasons for the rapid development of automotive navigation systems in Japan and the attention of the state to this industry is that the problems of the road in this country cannot be solved only by improving roads and increase their number, since the land is very expensive here, and construction requires considerable time . According to the Japanese, the optimization of the route of each car will help reduce the fatigue of drivers and ultimately - a decrease in the number of accidents and road accidents. An additional advantage may be more efficient use of fuel (and this is also a sick topic in poor resources of Japan) and improving the environmental situation. Realizing that ANS can play a significant role in solving all these problems, Japan began their active, strongly supported implementation by the state, and by 1997 more than 1 million automotive navigation systems were sold in the country. According to Matsushita Electric, the annual capacity of the ANS market amounted to 460 thousand systems in 1997-1998. and 500 thousand in 1998 - 1999 (forecast for 1999-2000 - 600 thousand systems).

A typical car navigation system consists of a computer with a CD-ROM or DVD, a non-ferrous liquid crystal display, a GPS receiver, a distance sensor and a gyroscope. Many Ans can also receive television signals and play musical CDs.

The main functions of these products are to determine the position of the vehicle and the driver manual on the route. The latter includes ensuring the driver's driver, the calculation of the distance and the path to the destination, the definition and reflection on the map of optimal routes, voice directions and show on the display of turns and intersections.

On the basis of the classification of the famous Japanese specialist of Dr. D. Kakhaner (D. Kahaner), the Labor Author "AtiP96.049: Car Navigation System Activities In Japan", five generations of ANS are distinguished.

Zero - not yet automotive navigation systems in a modern understanding, but only the embodiment of the first ideas and adventure technologies. Zero generation ANS used media on magnetic tapes To record cards. The cards themselves were very approximate and covered small territories.

The first (1987) is "traditional" navigation. Differs from the previous generation because the CD-ROM has become used as a carrier of cartographic information; The position of the car on the map, which in the zero generation of navigation systems it was necessary to determine by attentive study of the landscape outside the window, was now determined using the sensors - a geomagnetic sensor device, a speed sensor and a gyroscope; The quality of the cards also improved.

Second (1988) - "Traditional" navigation with feedback. In this generation navigation systems, it is possible to search for a destination (MAP Matching), issuing voice instructions to the driver and additional information about hotels and refueling.

Third (1990) - "Hybrid navigation". As a tool for determining the location of the car, in addition to the sensors began to use GPS. Information taken into account when planning a route was added information about traffic and weather conditions, including weather forecast.

Fourth (1998-1999) - Navigation "New Age" ("New Generation"). Recently, a variety of new products appeared that output automotive navigation systems to a higher technological level: it is a swap of additional cards via the Internet; Ability to drive a car by voice; Using a DVD as a carrier of cartographic information.

There are two types of automotive navigation systems for managing the driver on the route: with a demonstration of the map and without it. Studies on non-mantographic, "blind" systems are more actively carried out in Europe and America, where the map of the map during the movement of the car is considered dangerous. In Japan, it is believed that if the choice of the route is carried out by the system qualitatively, in order to bring the car to the destination, it is usually not required for a frequent demonstration simple maps. A few years ago, I heard about a car, in which the map with the route was projected directly on the windshield like a system of guidance in fighters, but I could not yet find documentary evidence of the existence of such systems. "Blind" Ass with voice control is more common in Europe and America than in Japan.

Car navigation system AVTC-505

The second type (driver maintains on the route with a display of detailed navigation cards) requires a high-quality display that shows the current vehicle position, destination, route, destination destination, etc. All this information is superimposed on basic map The locality with roads deposited on it and helps the driver choose the right turns when moving. Ans of this type is widespread in Japan.

Problems positioning

According to the car positioning method, modern car navigation systems can be classified as follows:

Satellite navigation;

Navigation using sensors;

Hybrid navigation using both types.

Satellite navigation system, using electronic cards stored on a CD-ROM or DVD, determines the location on the basis of the Global NavStar positioning system signals, which was created by the US Department of Defense in the 1970s and is a system of 24 satellites in six circular near-satellite orbits with a period of circulation of 12 hours, and GPS receivers. Satellite orbits are designed in such a way that at least four satellites can be seen from any point of earth at any time. Each GPS receiver, receiving a special navigation signal, calculates the distance to each of the visible satellites, measuring the time of the radio signal from the satellite to the receiver. After that, by triangulation, it determines its spatial coordinates (latitude, longitude and height above sea level).

Since the NavStar system was originally created for military purposes, the US Department of Defense was developed two codes (regimes): military and civilian. The GPS receiver using civil code determines the coordinates with an accuracy of 100 meters. Numerous factors distorted by the data are distinguished more accurate: the delay of radio signals during distribution in the ionosphere and atmosphere, inaccurate measurement of time, reverse the radio signals from various surfaces. In addition, some of the information received by civilian GPS receivers is distorted deliberately in order to prevent their use for military purposes by other countries.

The possibility of increasing the accuracy of determining coordinates is related to the use of differential GPS (DGPS). Obviously, many mistakes are the same for GPS receivers located within a few hundred kilometers from each other. One of these receivers, called the support station, is located in the place whose coordinates are defined for sure. Comparing the well-known coordinates with the measured, the GPS receiver generates amendments, and then transfers them by radio channel to consumers to clarify their coordinates.

It would seem that someone would need to be needed to measure the measurement sensors of the distance and gyros, if you determine the geographical coordinates of any object (as well as its speed, the direction of movement and many other parameters) is not difficult. The problem, however, is that in order for the system to work, at least three NAVSTAR satellites in the area of \u200b\u200bdirect visibility at the same time - and in cities built up with high buildings, it is almost impossible. In addition, the signal, repeatedly reflected from the walls and roofs of houses, is distorted. And the GPS tunnels do not work at all. But W. satellite navigation There are advantages: GPS is easy to install on a car, errors when it is used does not accumulate, DGPs provide high positioning accuracy and the price of GPS is now more than acceptable.

The system of determining the location of the car based on the use of sensors finds geographic coordinates according to the testimony of a gyroscope that determines the direction of the vehicle movement and the distance sensor, so errors accumulate. Thus, the longer path the car did, the greater the likelihood of a significant error in determining the coordinates and, therefore, in the leader's manual on the route. Hybrid systems use both types of positioning, which avoids most problems.

ANS Suppliers: Two-Poom World

The two largest ANS suppliers in Japan are Sony and Pioneer. In Europe, as already noted, the development, implementation and sales are engaged in their own, European manufacturers of consumer electronics. In the US, car navigation systems are mainly represented by American departments of Pioneer, Alpine and Etak, which is a Sony division. Americans are interested in traffic mainly, and Etak almost completely monopolized such a market niche as providing traffic maps in real-time all states without exception. What did not occupy ETAK, shared Pioneer and Sony among themselves. Thus, the market of automotive navigation systems is divided by European and Japanese companies.

No matter how the mid-90s are predetermined a quick and sharp drop in the price of ANS in the world, this, of course, did not happen, as the sharp drop in prices is not expected, for example, on refrigerators and other household appliances. Yes, the devices are improved, but the price changes insignificantly. So here. In 1996, Ans cost from $ 2,000 to $ 4,000. In 2000, their value fluctuates near the $ 1990 mark and the trends towards a significant decrease.