DE102009029333A1 - System, particularly navigation system for determining position of vehicle, has satellite positioning module to receive satellite signals, where current position of vehicle is determined according to satellite signals - Google Patents

Abstract

The system (1) has a satellite positioning module (2) to receive satellite signals, where current position of a vehicle is determined according to the satellite signals. A communication module (6) is provided for receiving Wireless local area network (WLAN)signals. An evaluation module (4) is provided to create a WLAN signal pattern based on the received WLAN signals, where the WLAN signal pattern is stored in a memory (9) according to a Medium access control (MAC)address. An independent claim is also included for a method for establishing a database for determining the position of a vehicle.

Description

The invention relates to a system for determining the position of a vehicle and to a method for constructing a database for determining the position of a vehicle via WLAN localization.

State of the art

Navigation systems for vehicles are well known. In general, the current position is determined and then a route to a given destination is calculated. For this purpose, digitized map data of a road network or road network in a memory, for example a CD-ROM or a DVD, is accessed. The map data may include, among other things, information about road patterns, road classes, intersections, turn conditions, and points-off interest. The amount and accuracy of the information depends on the capacity of the memory used.

The geographic location of the vehicle is typically determined by a satellite positioning system, such as a Global Positioning System (GPS) module or other comparable system. To improve the position determination, especially in areas with limited reception of the satellite signals, the direction of travel is determined by a gyroscope, the driving speed via speed sensors and / or driving changes via acceleration sensors and thus allows additional positioning based on coupling location.

An evaluation module determines based on the determined position data and the map data of the digitized road map the location of the vehicle with respect to the road map. In this case, occurring measurement errors of the sensors and / or inaccuracies in the road map can be corrected by a so-called "map matching" method. Since the position of the vehicle in the digitized road map is crucial to the navigation system, the determined position is compared with the map information so that the most probable location of the vehicle in the map for navigation is determined. For this purpose, the map matching the knowledge about the movements of the vehicle are used. For example, since vehicles can not move outside of fixed roads, the position may not be within built-up area but only on a digitized road.

With the help of satellite-based positioning systems, the current position can usually be determined with sufficient accuracy. However, this location requires a permanent contact with the radio signals emitting satellite. However, the reception of the satellite signals may be disturbed by the current environment of the vehicle, for example when driving through high-rise gorges or under a bridge, due to shading.

From the DE 101 05 901 A1 a method for determining the position of a land vehicle with a navigation system is known in which a combined analysis of the data receivable by a satellite navigation system and a terrestrial cellular mobile radio network data is made.

Out Peter Dornbusch, Max Zündt: "Realization of Position Locations in WLAN", ITG Conference "Technology and Applications for the Mobile Information Society", Dresden, 2002, VDE Verlag, ISBN 3-8007-2723-4 , WLAN-based location methods are also known.

Disclosure of the invention

The present invention provides a system for determining the position of a vehicle having a satellite positioning module for receiving satellite signals and determining a current position of the vehicle based on the satellite signals, a communication module for receiving WLAN signals, and an evaluation module for generating a WLAN signal pattern Basis of the received WLAN signals and for storing the WLAN signal pattern to the current position in a memory, if there is a limited reception of the satellite signals required for determining the position by means of the satellite positioning module at the current position.

The present invention also provides a method for setting up a database for determining the position of a vehicle via WLAN localization, in which WLAN signals are received, based on the received WLAN signals WLAN signal patterns are created, the current position of the vehicle using satellite-based Position determination and / or is determined by means of coupling location, and the WLAN signal patterns are stored to the current position, if there is a limited reception of required for satellite positioning satellite positioning signals at the current position.

According to the invention, Wi-Fi signal patterns - frequently referred to as WLAN fingerprints - are stored when the satellite signals are poorly received. In future rides, a navigation system can then in this, characterized by weak satellite reception section on use the WLAN signal pattern and thus determine the current position with increased accuracy using WLAN localization. The saving of a WLAN signal pattern as a function of the reception quality of the satellite signals at a respective current position has the advantage that WLAN signal patterns are stored only for those positions where the reception qualities of the satellite signals are insufficient for a reliable position determination with the aid of the satellite positioning module. As a result, the required storage capacity for storing the WLAN signal pattern is significantly limited. The navigation system according to the invention and the method according to the invention also have the advantage that the database required for WLAN localization is built up successively, completely automatically.

According to one embodiment of the system according to the invention, a monitoring module is provided, which monitors the current signal strength of the satellite signals, wherein the WLAN signal pattern is stored at the current position in the memory, if at the current position at least one of the satellite signals required for determining the position by means of the satellite positioning module below a predetermined threshold.

With the aid of the monitoring module, which monitors the current signal strength of the satellite signals, it is possible to detect a currently limited reception of the satellite signals. Saving the WLAN signal pattern is only necessary if the number of satellite signals received with sufficient signal strength is no longer sufficient to reliably determine the position.

As an alternative to the active measurement of the signal strength of the satellite signals, according to a further embodiment of the invention it is also possible to mark sections of the route in which a limited reception of the satellite signals required for determining the position by means of the satellite positioning module is to be indicated in a digitized road map of the navigation system and the WLAN Store signal pattern to the current position in the memory, if the current position is within such a section. In this case, sections of the route, such as high-rise canyons or under bridges, are marked in advance in the map material of the navigation system used as route sections with potential reception weaknesses. In this way, it is possible to dispense with a current measurement of the signal strengths of the satellite signals.

According to one embodiment of the invention, the communication module and / or the evaluation module is activated only when a limited reception of the satellite signals required for determining the position with the aid of the satellite positioning module is present at a current position. This in turn may result from an up-to-date determination of the reception quality of the satellite signals or from a corresponding identification in the digitized road map. In this way, unnecessary data traffic and / or unnecessary data processing can be safely avoided.

An embodiment of the invention provides that the respective current position are determined on the basis of the satellite signals and / or on the basis of coupling location, in particular with the aid of map matching methods. The additional use of coupling detection systems and, where appropriate, the aid of map matching methods make it possible to determine the current position even in sections in which the signal strengths of the satellite signals alone are no longer sufficient for a reliable determination of the current position with the aid of the satellite positioning module , In this way, it is possible to store WLAN signal pattern also to current positions at which the reception weakness of the satellite signals is so strong that a position determination based only on satellite signals is no longer possible.

According to a further embodiment of the invention, the signal strengths of the received WLAN signals are determined and the WLAN signal pattern is stored on the basis of MAC addresses of receivable WLAN base stations (also referred to as access points) and the associated signal strengths. The storage of the MAC addresses of all base stations from which a WLAN signal was received and the respectively associated signal strengths represents a simple form of a recognizable signal pattern or fingerprint.

Further features and advantages of embodiments of the invention will become apparent from the following description with reference to the accompanying figure.

Brief description of the figure

1 shows a schematic block diagram of a navigation system according to the invention.

Description of the embodiments

1 shows a schematic block diagram of a system according to the invention 1 for determining the position of a vehicle. A satellite location module 2 receives via a first antenna 3 Satellite signals. The satellite signals are radio signals of a satellite-based Locating system, for example, the Global Positioning System GPS, the Galileo system or a similar other system. The satellite location module 2 determines current position data based on the satellite signals. An evaluation module 4 determined on the basis of the determined position data and map data of a digitized road map which is stored in a map memory 5 stored, the location of the vehicle in relation to the road map. In this case, occurring measurement errors of the sensors and / or inaccuracies in the road map can be corrected by "map matching" method.

A communication module 6 is intended to have a second antenna 7 Send wireless signals and receive, with the invention, only the reception of wireless signals is important. Both the satellite location module 2 as well as the communication module 6 are with the evaluation module 4 connected. The evaluation module 4 At a current position, it evaluates all WLAN signals received from WLAN base stations, in particular with regard to their signal strengths, and uses them to generate a WLAN signal pattern. In the simplest case, this consists of a MAC address of the respective WLAN base station and the signal strength of the associated WLAN signal at a current position. In addition, the evaluation module determines 4 Also, whether at the current position a limited reception of the position for the positioning using the satellite positioning module 2 required satellite signals is present. For this purpose, according to the in 1 illustrated embodiment, a monitoring module 8th provided, which monitors the current signal strengths of the satellite signals. Represents the monitoring module 8th determined that at the current position at least one of the position determination using the satellite positioning module 2 required satellite signals is below a predetermined threshold, the generated WLAN signal pattern for this current position in a memory 9 saved and is thus available for future WLAN localization at this position.

Alternatively to the illustrated embodiment with a monitoring module 8th It is also possible in the in the map memory 5 filed digitized road map sections with expected limited reception, for example, due to shading in skyscraper gorges to mark and the WLAN signal pattern for the current position then in the memory 9 store if the current position falls in such a marked section of road.

Alternatively to the illustrated embodiment of the evaluation module 4 as a separate module, which also includes the monitoring module 8th includes, is the evaluation module 6 and / or the monitoring module 8th also in the satellite location module 2 or the communication module 6 integrated. It is also possible for the creation and storage of the WLAN signal pattern on the one hand and for the determination of the location of the vehicle with respect to the road map on the other hand provide separate evaluation modules, which in turn, individually or together in the satellite positioning module 2 or the communication module 6 can be integrated.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10105901 A1 [0006]

Cited non-patent literature

• Peter Dornbusch, Max Zündt: "Realization of Position Locations in WLAN", ITG Conference "Technology and Applications for the Mobile Information Society", Dresden, 2002, VDE Verlag, ISBN 3-8007-2723-4 [0007]

Claims (7)

System for determining the position of a vehicle with - a satellite positioning module ( 2 ) for receiving satellite signals and for determining a current position of the vehicle on the basis of the satellite signals, - a communication module ( 6 ) for receiving WLAN signals and - an evaluation module ( 4 ) for generating a WLAN signal pattern on the basis of the received WLAN signals and for storing the WLAN signal pattern to the current position of the vehicle in a memory ( 9 ), if at the current position there is a limited reception of the satellite signals required for determining the position with the aid of the satellite positioning module. System according to one of claims 1 or 2, in which a monitoring module ( 8th ), which monitors the current signal strength of the satellite signals, the WLAN signal pattern being at the current position in the memory ( 9 ) is stored, if at the current position at least one of the position for determining the position using the satellite positioning module ( 2 ) is below a predetermined threshold. A system according to any one of claims 1 or 2, wherein restricted-receive path sections for determining position using the satellite positioning module ( 2 ) are marked in a stored digitized road map and the WLAN signal pattern is stored to the current position if the current position is within such a section. System according to one of the preceding claims, wherein the communication module ( 6 ) and / or the evaluation module ( 4 ) are activated if, at the current position, there is a limited reception of the position to be determined with the aid of the satellite positioning module ( 2 ) is present satellite signals. System according to one of the preceding claims, wherein the current position on the basis of the satellite signals and / or on the basis of coupling location, in particular with the aid of map matching method, is determined. Method for constructing a database for determining the position of a vehicle via WLAN localization, in which - WLAN signals are received, - WLAN signal patterns are generated on the basis of the received WLAN signals, - The current position of the vehicle is determined by means of satellite-based position determination and / or with the aid of coupling location, and - The WLAN signal pattern are stored to the current position, if there is a limited reception of required for satellite positioning satellite signals at the current position. The method of claim 6, wherein the signal strengths of the received WLAN signals are determined and the WLAN signal pattern is stored on the basis of MAC addresses of receivable WLAN base stations and the associated signal strengths.

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