EP1796059A2 - Method for determination of adjusted current position data, in particular for determining current vehicle positions - Google Patents

Abstract

The method involves determining actual position data of a vehicle (8) with the help of position information that are radiated by satellites, and comparing the determined actual position data with electronic stored geo data. The determined actual position data are compared with reference position data. A mismatch is determined from the comparison of the data, where all following, determined actual position data are corrected with the mismatch and are converted to the corrected actual position data. An independent claim is also included for a road charge collection system comprising mobile detection units for arrangement in a vehicle.

Description

The invention relates to a method for determining corrected current position data, in particular for the determination of corrected current vehicle positions, in which by means of position information radiating devices, preferably satellites, determined current position data and this electronically stored geodata, which at least part of the road network Geographical area include, according to the preamble of claim 1 and a toll collection system comprising mobile detection units (OBUs) for placement in a vehicle, each mobile detection unit at least one location unit for the purpose of determining current position data using position information radiating devices, preferably satellites, and a processor unit, which determines the determined current position data with geodata stored in the mobile detection unit, which at least one Part of the road network of a geographical area, for purposes of current position determination of a vehicle compares, according to the preamble of claim 13.

The invention also relates to a mobile detection unit for use in a toll collection system according to claim 14.

Positioning systems for locating vehicles are already widely used in the general traffic scene. In particular, electronic toll systems always win because of the steadily increasing volume of traffic greater importance to levy a fixed fee for the use of roads, bridges, tunnels or other infrastructure structures.

Especially in heavy traffic for toll calculation in addition to an access-related tolls in the form of a time-limited "vignette" also use-dependent tolls application, the amount of toll depends on the actual route usage and based on distances covered, traversed sections, tunnel crossings or even time stays in certain Zones can be calculated.

The usage-dependent toll charging can take place in the sense of an unimpeded traffic flow via satellite-based positioning systems, so that a stop of the vehicles at toll stations or a binding to prescribed lanes is unnecessary.

Already known, usage-dependent toll collection systems work with mobile detection units, so-called OBUs (On Board Units). These are devices that are installed in a vehicle to allow automatic toll settlement within a toll collection system based on the distance covered by the vehicle in the toll collection system, where they detect the basis for calculating tolls, namely the distance covered or the toll charge The used sections. The German, French, Italian, Austrian and Spanish motorway operators, but also increasingly other countries inside and outside Europe, use OBUs to detect distances covered or sections of the route traveled. The OBUs can be purchased or rented and are provided with a unique for each toll collection system identifier that in the course of the issuing process, to a specific natural or legal person, in order to allow offsetting of the tolls incurred.

In principle, the use of mobile detection units in two different toll collection systems is common, namely on the one hand in GNSS (Global Navigation Satellite System) based systems and on the other hand in infrastructure based systems.

GNSS-based systems work in most cases using the satellite positioning system known by the abbreviation GPS (Global Positioning System). Other satellite positioning systems are also available or others are already in planning. The OBU can make a position determination using the signals emitted by the satellites. This makes it possible to determine the path that the OBU travels within a toll collection system.

Infrastructure-based systems work with infrastructure elements set up on the roads, such as toll portals for position determination. In this case, for example, the OBU can communicate via microwaves with the toll portals, whereby it is possible by means of this communication to reconstruct which route sections were traveled by the OBU. Infrastructure-based systems are known in which the localization unit actively transmits signals to the toll portals and transmits these position data obtained in this manner to a central processing unit or a central computer network for the purpose of calculating tolls. However, infrastructure-based systems are also known in which the localization unit, on the basis of the received position information of the toll portals, has a credit that the mobile detection unit, for example, has via a prepaid card, debited from the prepaid card.

For the present invention, especially the GNSS based systems are of interest. As compared to infrastructure based systems, they have the advantage that no additional infrastructure needs to be created along the route network to be tolled, which reduces the costs of setting up and operating a GNSS based toll collection system over an infrastructure based toll collection system.

The mobile detection units used in GNSS-based systems are equipped at least with a localization unit and with at least one transceiver unit.

The localization unit is used to determine the current position data of the OBU and thus of the vehicle in which the OBU is arranged. During the determination, under certain circumstances, which will not be discussed here in detail, data additionally detected on the vehicle, such as gyro data or tacho data, may also be used.

The send / receive unit is used to register the OBU in the toll collection system and to establish a data connection to a central processing unit or a central computer network. In this way, the OBU can log in the toll operator's system and transfer those data to the central processing unit or the central computer network, which are required in the toll collection system for billing tolls. Currently these send / receive units work after the GSM Default. In principle, however, other systems that are suitable for wireless data transmission can be used.

In the case of GNSS-based systems, two different variants of the processing of the current position data determined by means of the localization unit are generally known.

In a first variant, the current position data determined by the localization unit are evaluated directly by the OBU, ie. these are compared directly by the OBU with geodata stored in the OBU for the purpose of toll object recognition. In this case, the OBU decides whether toll roads have been covered or not, ie. It identifies those areas, routes or stretch sections that are subject to toll and were driven by the OBU or the corresponding vehicle. The resulting data can then either directly, processed, for example, encrypted and / or compressed, or not processed, to the central processing unit or the central computer network for the purpose of linking with tariff data and accounting transmitted.

Alternatively, according to the first variant, the data resulting from the toll object recognition can be linked by the OBU with corresponding tariff data, which are also stored in the OBU in this case, to calculate a toll amount, which then either via the data connection to the central processing unit or to the central computer network is transmitted, where then only the accounting takes place as such or is debited from a prepaid card directly to the OBU.

In the case of GNSS-based systems, toll-object recognition is understood to be the comparison of that of the Localization unit of the mobile detection unit determined current position data stored in the toll collection system geodata and toll objects contained therein.

Geodata describes the geographic area to be tolled and also includes at least part of the road network of that geographic area. Within the geodata so-called geo-objects are defined, which describe defined sections, positions or areas in the geographical area. For example, sections defined as geo-objects are those roads and / or areas for the use of which toll is payable. In this case, the geo objects are toll objects at the same time. But also other areas, for example, streets that are not too busy, can be defined as geo-objects. If the determined current position data are located within tolling geoobjects (toll objects) or if the crossing of a boundary of such a geoobject (toll objects) has been detected, then the track section within the geoobject (toll object) or the geo object that has crossed the border is detected (Toll object) section of the track to pay a toll fee, which are determined by linking with corresponding tariff data.

This variant (decentralized system) requires an equipped with sufficient computing power and sufficient space OBU, since on the one hand all geodata of the toll route network must be stored in the OBU and on the other hand, the calculation of whether toll roads were traveled, so the toll object recognition, also in the OBU takes place. In the event that the calculation of the toll fee due takes place in the OBU, ie the linkage of the toll object recognition data received with tariff data, additional computing power and additional storage space for tariff data is required. However, the advantage in such an embodiment variant is that only the data from the toll object recognition or the toll fee data has to be transmitted to the central processing unit or the central computer network. A transfer of the current position data determined by the localization unit to the central processing unit or the central computer network is not required. However, changes in geodata or tariff data require updating them in each OBU via the data link. With such changes, however, the required data transfer can be kept relatively low, by transmitting only those data which have been subjected to a change.

The second variant of a toll collection system (central system) provides that the current position data determined by the localization unit, processed or unprocessed, are transmitted in their entirety via the data connection to the central processing unit or central computer network and the evaluation (toll object recognition, link with Tariff data, accounting) is carried out centrally. This system has the advantage that changes in the geodata or tariff data can be very easily entered into the central processing unit or the central computer network and thus no update of each operating OBU is required. However, this variant has the disadvantage that a great many current position data must be transmitted to the central processing unit or the central computer network.

While in infrastructure based positioning systems, the mobile detection units when passing through stationary toll gantries can communicate with these by means of DSRC (Dedicated Short Range Communication) interface based on microwave radio and so a unique and accurate positioning of the mobile detection unit is possible results in satellite-controlled positioning systems, the problem that the localization unit for proper determination of the current position data is always dependent on an undisturbed GNSS signal reception. If this signal reception is temporarily disturbed, such as in tunnels or unusual topographical landscape structures, an exact localization of the vehicle or the OBU can no longer be guaranteed.

Since the elliptical orbit of the satellites is influenced by the gravity acting on them and the gravitational force is subject to various factors which are difficult to calculate, there are irregular deviations (drift) of the satellites from their theoretically planned orbit. Among these influencing factors is the fact that the earth is flattened and the mass in its interior is not distributed spherically around its center. These conditions also combine with relevant influences of other celestial bodies such as sun and moon.

Thus, by subjecting gravity to periodic and irregular fluctuations, the satellite moves faster, once slower or once higher, once deeper than a forecast would indicate. Due to the large number of orbits, the small deviations sometimes add up to considerable amounts, so that a currently calculated satellite orbit is invalid again after quite some time.

In the case of satellites, which are used for position determination in GNSS systems, this causes an inaccuracy in the determination of the current position data of the localization unit and thus of the mobile detection unit.

In order to correct this inaccuracy, control stations must be provided with precisely defined positions on the surface of the earth, which register the deviation. In the case of the GPS system, five so-called monitoring stations are distributed over the globe, which receive the signals sent by the satellites and compare them with specific target specifications. These monitor stations have an upload facility to send corrections to the respective satellites. The updated information of the exact position of each individual satellite is sent by the latter itself at regular intervals, approximately once per hour to all localization units, so that they can take into account the deviation of the satellite in its position calculation.

In practice, however, this means that for critical applications where a very exact determination of current position data is required, after 30 minutes, a relevant deviation of the GNSS signal data or the position data determined therefrom is recorded and the position determination is therefore insufficient.

In toll collection systems, these deviations prepare in places where parallel roads are close to each other and have multiple entrances and exits, for example by main roads running parallel to the highway or in longer underpasses, difficulties and cause problems in determining whether toll roads are driving were or not. The possibility of a misjudgment in this regard would lead to unjustifiable offsetting errors in the expulsion of the toll due to the toll user.

It is therefore the object of the present invention to provide a method for ascertaining current position data in a GNSS position determination system, in particular a toll collection system, which compensates for the abovementioned deviations and thus enables an exact position determination.

This object is achieved by a method having the characterizing features of claim 1.

In this method for the determination of corrected current position data, in particular for the determination of corrected current vehicle positions, in which by means of position information radiating devices, preferably satellites, determined current position data and electronically stored geodata, which include at least part of the road network of a geographical area , are compared, it is provided according to the invention that the determined current position data are compared with reference position data and an offset is determined from this comparison, with which all subsequent, determined current position data are corrected and converted to corrected current position data.

Such a method according to the invention can preferably be used in a toll collection system, but can also be used for a variety of other applications, such as the fleet management of freight forwarders, for electronic tracking of a freight by the customer or for the automatic guidance of electronic driving books of motor vehicles.

For a variety of applications, the determined current position data are completely sufficient to use this as a basis for further calculations. For some applications, however, these data are insufficiently accurate for the reasons described above.

By defining reference position data within the geospatial data, in defined areas of the road network where particular accuracy is required in the determination of current position data, it is possible to take into account the inaccuracy in the processing of the position information radiated by the satellite and to correspondingly determine the current position data Correct by comparing the determined current position data at defined times, for example, shortly before the arrival in such defined as critically defined area automatically with reference position data. From the difference between reference position data and the determined current position data, an offset is then determined, which is used to determine corrected current position data. For all determined current position data within the defined range, the offset is subsequently added and the corrected current position data is thereby corrected.

The beginning of the method is automatically triggered according to the characterizing features of claim 2 by a defined event. While a conventional position determination method without correction can be used in a large number of applications, it is necessary to carry out the method according to the invention for defined areas which are classified as critical.

According to the characterizing features of claim 3, the defined event is the event in which the determined current position data are within or on a reference range of the electronically stored geodata, for example, that time of registered entry of a vehicle in a defined area geodata. The reference range can be defined by any limit values within the spatial data, for example, by lines or polygonal lines, wherein this reference range is selected to be correspondingly large, so that even with maximum inaccuracy of the determined current position data they come to lie within the reference range. If this match occurs, it is automatically known that the determined current position data should actually coincide with the reference position data assigned to the reference range. If this is not the case, the offset according to the invention can be determined therefrom.

According to the invention, therefore, according to claim 6, each reference range associated with reference position data, which are needed for the calculation of the offset.

The named reference region can be arbitrarily selected position data within the geodata, which are stored either within the geodata itself or in the form of a data set or polygonal superimposed thereon. Preferably, the reference region according to the characterizing features of claim 4 is a geo-object predefined within the geodata. Under a geo object, geometrically determined elements can be punctiform, linear, planar or even spatial.

To serve as a starting point for the subsequent procedure for positional data correction, the reference range is or the Geoobjekt arranged according to the characterizing features of claim 5 before an intersection and / or an entrance or exit in the road network of geodata. In practice, in this way each relevant entry and exit or intersection is detected in front of a defined area in which an increased accuracy of the position determination is required.

According to the characterizing features of claim 7, which describe an alternative embodiment of the invention, the defined event may be the passing of roadside toll infrastructure elements, for example toll gates or support beacons. Toll infrastructure elements are already known from non-satellite toll collection systems. They communicate with the OBU by means of course radio (DSRC).
If the passage of such a toll infrastructure element is detected, since, according to the characterizing features of claim 8, each toll infrastructure element is assigned reference position data, the exact position of the vehicle is automatically known and thus also the exact reference position data, which is subsequently used to calculate the offset Calculation of the corrected position data can be used.

The characterizing features of claim 9 furthermore describe the possibility of using, as a defined event for determining the offset or the position data correction, the point in time at which a defined sequence of determined current position data is registered. As a triggering event for the position correction method according to the invention thus a computationally perceptible change in the vehicle movement is set. For example, based on the known position determination method, the direction and speed of the vehicle can be calculated, and thereby a characteristic driving distance of the vehicle be recognized, which is compared with stored characteristic routes and the application of a method according to the invention for determining the offset and for correcting the determined current position data is applied in accordance. By recognizing the characteristic travel route and on the basis of the current position data determined at the time of the recognition, it is in turn known that the determined current position data should actually correspond to certain reference position data. From this information, in turn, the inventive offset can be determined.

Regardless of the type of triggering event, the duration of the calculation of corrected current position data may be limited according to the characterizing features of claim 10. However, instead of the passage of any predetermined period of time from the triggering event, the period of execution of the method according to the invention may also be limited according to the characterizing features of claim 11 by defining a certain number of distance units, after which the vehicle will cope with the correction of corrected current position data becomes.

According to the characterizing features of claim 12, it is also possible that the conversion to corrected current position data takes place until agreement or non-compliance of these with a defined region of the electronically stored geodata occurs. Here, therefore, the passage of the vehicle from defined zones or geo-objects, preferably the re-emergence of the vehicle from an observed defined area of the road network, is accompanied by a termination of the execution of the method according to the invention. If the vehicle reaches another one defined area of the road network or a geo object corresponding thereto defined geo object, the inventive conversion of the determined current position data is restarted. This results in a complete monitoring of the observed vehicle with regard to its current route selection.

Claim 13 describes a toll collection system in which the method described in claims 1 to 12 is used. It comprises mobile detection units (OBUs) for arrangement in a vehicle, each mobile detection unit having at least one location unit for the purpose of determining current position data by means of position information emitting devices, preferably satellites, and a processor unit containing the determined current position data in the mobile detection unit stored geodata, which include at least part of the road network of a geographical area, for the purpose of current position determination of a vehicle compares. By means of the processor unit, an offset from the comparison of the ascertained current position data and reference position data can be ascertained in the manner already described, with which all subsequent, ascertained current position data can be corrected and converted to corrected current position data.

Claim 14 describes a mobile detection unit (OBU) for use in a toll collection system according to claim 13, comprising at least one location unit and a processor unit.

The invention will now be explained in more detail with reference to an embodiment. The exemplary embodiment describes the application of the method according to the invention in a toll collection system. The inventive method for As a matter of principle, however, the determination of corrected current position data can also be used in ship and domestic traffic as well as in all other application areas of telematics and navigation technology.

Fig.1

eine schematische Darstellung eines Versatzes von aktuellen Positionsdaten

Fig.2

eine schematische Darstellung einer Landkarte mit erfindungsgemäßen Referenzbereichen

Fig.3

eine schematische Darstellung eines erfindungsgemäßen Verfahrens

Showing:

Fig.1

a schematic representation of an offset of current position data

Fig.2

a schematic representation of a map with reference areas according to the invention

Figure 3

a schematic representation of a method according to the invention

The method according to the invention is based on the determination of current vehicle positions by means of a mobile detection unit (OBU) which can be installed in a vehicle 8. This comprises as a basic component a localization unit, in particular a GNSS localization unit, which is able to use positional information emitting devices, in particular from the transit time of satellite signals, hereinafter called GNSS signal data to determine current position data, ie the current position of OBU or the vehicle 8 to calculate. In this way, continuously ascertained current position data 4 are provided which serve both as a basis for further arithmetic operations and as for the representation of the current vehicle positions, for example in a known electronic-graphic and / or acoustic form. The localization unit can also determine the direction and speed of the vehicle 8 with the aid of the GNSS signal data.

For communication with a central processing unit or a central computer network of the toll operator of the toll collection system, the OBU further comprises components for Construction of a data connection, preferably a GSM radio-based transmitting / receiving unit.

The OBU is provided with a memory unit in which geographic information in digital form, so-called geodata, are stored. These geodata represent a virtual map that includes at least those roads for which toll is payable. Of course, other roads that are not subject to toll and any other topographical conditions of the geodata may be included.

By continuously ascertaining the current position data and comparing these with the geodata, in particular with regard to overlaps with geoobjects defined within them, an assignment of the current vehicle position with respect to the frequented road can be made and it can thus be recognized whether the driver is currently using a tolled section of the route or not , If the determined current position data 4 are located, for example, within tolling geoobjects, which in this case are also referred to as toll objects, or if the crossing of a boundary of such a geoobject (toll objects) has been registered, then appropriate toll charges of the toll participant are to be made.

It is always essential that the determined current position data coincide with the actual position data of the vehicle 8 or approximately coincide with high accuracy. However, since the GNSS satellites have different irradiation positions corresponding to the course of the day due to more complex gravitational phenomena acting on the satellite body during its orbit, those of the Localization unit received GNSS signal data processed with an incalculable inaccuracy, resulting in a fault liability (drift) of the determined current position data 4 results.

On the basis of geostationary monitoring stations, therefore, periodically updated information of the exact satellite positions are transmitted to the satellites (upload) and from these in turn to the individual localization units (download) so that they can take into account the faultiness of the GNSS signal data during the vehicle position determination.

However, the intervals of the updates are in many cases not sufficient to allow the required accuracy of the position determination. Already about 30 minutes after a successful update of the satellite position information (download) is in many cases already no longer negligible change in Einstrahlstellung the satellites or the corresponding signal propagation time and thus a fault liability of the GNSS signal data recorded a reliable localization of Vehicle 8, especially when this moves in the field of roads with closely spaced track sections and multiple entrances and exits, no longer makes it possible to guarantee. In toll collection systems, depending on the complexity of the road layout, the maximum allowable error may be reached in less than 30 minutes since the last update.

Such an inaccuracy of the current position data 4 of the vehicle 8 determined on the basis of the faulty GNSS signal data is shown in a simplified form in FIG. The vehicle 8 shown by a triangle actually travels a road 2 in the direction of travel 14. The basis of the GNSS signal data determined current position data 4, however, are faulty, so that they would give an incorrect course according to the dotted line 16. The determined current position data 4 thus do not correspond to the actual position data of the vehicle 8.

For the assignment of the vehicle 8 to the currently traveled route, this becomes problematic only from that area in which another road train 15, for example a toll road (toll object), crosses the road 2 in the area shown with reference arrow 17 and hence at a close distance parallel to the road 2 continues and that at the point of the error-prone current position data. As can be seen in the illustration, there is the danger in this parallel section that the driving on a toll road is recognized, since the determined current position data lie within the toll object 15.

According to the invention defined areas 1 are therefore provided within the geodata, which are classified as critical road systems as critical and therefore make a determination of the current position data of the vehicle 8 with increased accuracy necessary, these defined areas 1 each having at least one defined reference area 3 is assigned. This reference area 3 is preferably defined as a geobalance object 3 and is ideally arranged immediately before the junction of a street in a defined area 1 in order to serve as the starting point for the following method of position data correction schematically illustrated in FIG. Each reference area 3 is again assigned reference position data 5, which are decisive for the comparison described below.

At the time in which the vehicle 8 passes the geo-object 3, for example by exceeding its limits, the determined current position data of the vehicle 8 are within the geo-object 3 or, for example, the current position data 8 coincide with spatial data defining the geo-object 3, the The current position data 4 determined by the localization unit are automatically compared with the reference position data 5 assigned to the respective reference area 3. These reference position data 5 stored in the storage unit correspond to the vehicle position from which it is assumed that the vehicle 8 actually holds it at the time of passing the geo object 3.

From the comparison or the difference of the current position data 4 and the reference position data 5, an offset 6 is determined, with which from now on all the following, determined by the localization unit within the defined area 1 current position data 4 and converted to corrected current position data 7 are converted. The corrected current position data 7 now correspond with higher accuracy to the actual location of the vehicle 8 than the determined current position data 4 without correction and allow even in a densely interlinked road network with many entrances and exits of individual routes an exact assignment, on which road the vehicle 8 is currently located.

As a defined event for starting the application of the method according to the invention that time can be used, in which the determined current position data 4 are recognized as lying within or on a reference area 3 of the electronically stored geodata. For example, a transfer of the vehicle 8 via a defined as Geoobjekt 3 line or a congruence of the current vehicle position with a point defined as Geoobjekt 3 or the entrance of the vehicle 8 in a defined as Geoobjekt 3 polygon or in a radius formed by a defined point as a defined event be provided at in which the ascertained current position data 4 are compared with the reference position data 5. The respective reference range 3 is always to be chosen so that even with the maximum possible inaccuracy of the GNSS signal data, the passage of the reference range 3 is reliably detected.

The comparison goes along with the assumption that the vehicle 8 is actually located at the location of the reference position data 5, especially since these are selected so that it can be the only possible actual location of the vehicle 8 at the time of passing the reference area 3. The possible error liability of this computational assumption is marginal and allows a sufficient differentiation of even closely spaced and intersecting lanes of the road network.

Alternatively, as a defined event for starting the method according to the invention, it is also possible to use the passage of a roadside infrastructure element such as, for example, a tollgate or a support beacon. These infrastructure elements can be used, for example, in particularly critical areas instead of the reference area 3. The OBU recognizes the passing of the infrastructure element due to its ability to communicate via DSRC. Each infrastructure element, as well as each reference area, is assigned 3 reference position data 5, so that an offset can be calculated when an infrastructure element passes.

Likewise, as a defined event for starting the application of the method according to the invention but also that time can be used in which a characteristic driving behavior is registered by the vehicle 8, for example in the form of a sequence of characteristic changes in direction or a characteristic acceleration or braking of the vehicle 8. In one In this case, the defined event is the registered occurrence of a defined sequence of determined current position data 4. Both direction and speed of the vehicle 8 can be determined in this connection on the basis of the Doppler effect of electromagnetic waves in a known manner. The recognition of the defined sequence of determined current position data 4 replaces the passage of a reference range in this case.

As a further defined event for starting the application of the method according to the invention, in the simplest case of application, a manual initiation of the method according to the invention by a vehicle occupant or a rhythmically programmed startup of the method according to the invention at fixed intervals would be conceivable.

The duration of the application of the method according to the invention for ascertaining corrected current position data 7 can be arbitrarily determined and is essentially dependent on the size of the defined critical area 1. Thus, for example, the lapse of a defined period of time from the defined event can be determined; However, the embodiment of the method according to the invention can also be limited by defining a specific number of distance units, after which the detection by the vehicle 8 of the corrected current position data 7 ends automatically.

A particularly practicable possibility is that the conversion to corrected current position data 7 is performed only for the recognized period of entry or re-exit of the vehicle 8 in or out of the defined area 1 of the geodata. The method according to the invention is thus terminated when the vehicle 8 again frequents a region of the spatial data classified as non-critical. In such case, again, as is common in the general state of the art, only the current position data 4 determined by the localization unit for vehicle position recognition or toll calculation are used, since in such an application they again prove to be sufficiently accurate. However, if the vehicle 8 again reaches a defined critical area 1 of the road network or a correspondingly defined geo object 3, then the inventive method for determining corrected current position data 7 is restarted.

In order to determine the difference between the current position data 4 and the reference position data 5 ascertained according to GNSS signal data or to apply to all subsequently determined current position data 4 within the defined area 1 with the offset 6, in the simplest case a matching of the X takes place by means of subtraction or addition / Y or polar coordinate values, possibly even the Z coordinate values in three-dimensional position detection, taking into account the geographical height position of the vehicle 8.

According to the invention, it is further possible to provide specific calculation algorithms for the refined simulation of a change in the offset 6 over a specific route. If appropriate characteristic parameters are known, the determined offset 6 can be modified along selected routes within defined sub-areas 9 in order to arrive at a more precise determination of the current vehicle position.

In the flowchart according to FIG. 3, the determination of corrected current position data 7 for a point 11 drawn in a road guidance according to FIG. 2 has been shown by way of example. Since the offset 6 determined on the geobalance object 3 barely changes for the entire defined region 1 assigned to it, the offset 6 once determined when the geoobject 3 traverses it remains valid for all points of the carriageways lying in the defined region 1. Thus, based on the offset 6, the actual position of the vehicle 8 at the points 12 or 13 can also be determined with sufficient accuracy by applying the same offset 6 to the determined current position data 4 for the points 12 or 13.

The hitherto existing problem of not being able to reliably differentiate whether a vehicle 8 traveling in the direction of movement 14 according to FIG. 2 now follows the path in the direction of points 11 or 12 or the path in the direction of points 13 and 10 in the case of side-by-side roads, Since both paths have an approximately parallel course, that is defused by the inventive method. For the set case that the section of road is tolled according to item 11 or 12, but not tolled according to item 13 or 10 or provided with a different toll class, an exact verification of the made choice of the driver can be made and a clear toll settlement accordingly the utilized traffic routes are made.

To support GNSS position determination in the OBU, it is sometimes common to use additional location sensors. Via a so-called "coupling location", the vehicle movement and the vehicle direction are determined on the basis of a gyro installed in the vehicle (gyroscope with piezo sensors) and a decrease in vehicle speed by the tachometer. The GNSS Positioning System independent coupling location is constantly aligned with the satellite positioning and makes it possible that the automatic position detection system for a short period even without GNSS signal manages. However, this system is subject to considerable inaccuracies and should be made unnecessary by the described inventive measures, although a system according to the invention may possibly also interact with a system installed on board coupling system.

In order to be able to exactly differentiate all confusing roadways, within a defined area 1, ideally each relevant entry and exit of a street is assigned an upstream reference area or a geoobject 3, whereby it can optionally be provided that within an area 1 any number of subregions 9 together with associated further reference regions or geo-objects 10 are defined in order to achieve a refinement of the locating accuracy in special cases of topography or an already defined area 1, within which the road is changed by current infrastructure measures to supplement necessary additional information or position data. Autonomously defined regions 1 or regions 9 can also intersect arbitrarily, intermesh or adjoin one another. The circular extent of the defined regions 1 and 9 shown in FIG. 2 can likewise be replaced by any other polygonal shape. for example, by quadrants or seamlessly adjacent hexagons.

The geo-objects 3 shown in FIG. 2 as points or circles can also be any shapes that are varied in any way, for example selected surfaces, lines or points which are arranged in the vicinity of defined streets or geodata or intersect these. Preferably, however, they are arranged directly in front of the junction of a road in a defined area 1.

Expediently, the geoboards 3 or 10 are defined by Cartesian coordinates or polar coordinates, the offset 6 also being able to be defined in three dimensions by virtue of both the received position information or GNSS signal data and the actual position data 5 stored in the memory unit with respect to a third spatial dimension be evaluated.

In order to be able to forward traffic-related changes of the routing or changes in toll collection immediately to the users of the position detection system in the case of a decentralized toll collection system, the arrangement of the defined areas 1 and the reference areas or Geoobjekte 3 within the onboard virtual map via radio data transmission, preferably via the GSM transmission / reception unit of the OBU can be updated.

At road sections, in particular tunnels and underpasses, where topographical conditions make it impossible to receive GNSS signal data, the current position data 4 determined when the signal reception returns after crossing these sections can be corrected on the basis of a reference area or geo object 3 located downstream of the road section current Position data 7 are converted in order to determine the exact distance covered by calculation.

LIST OF REFERENCE NUMBERS

1 or 9

Area

2.15

Straßenzug

3

reference range

4.7

position data

5

Reference position data

6

offset

8th

vehicle

9

subregions

10,11,12,13

Point

14

direction of travel

15

toll object

16

line

17

reference arrow

Claims (14)

Method for ascertaining corrected current position data, in particular for determining corrected current vehicle positions, in which devices using position information, preferably satellites, determine current position data (4) and these with electronically stored geodata which comprise at least part of the road network of a geographic area , are compared, characterized in that the determined current position data (4) with reference position data (5) are compared and from this comparison, an offset (6) is determined, with which all subsequent, determined current position data (4) corrected and corrected to current Position data (7) are converted. Method for determining current position data according to claim 1, characterized in that the start of the method is triggered automatically by a defined event. Method for determining current position data according to Claim 2, characterized in that the defined event is the event in which the determined current position data (4) lie within or on a reference region (3) of the electronically stored geodata. Method for determining current position data according to claim 3, characterized in that the reference area (3) is a geo-object (3) predefined within the geodata. Method for determining current position data according to one of Claims 3 or 4, characterized in that the Reference area (3) of the electronically stored geodata or Geoobjekt (3) is arranged in front of an intersection and / or an entrance or exit in the road network. Method for determining current position data according to one of Claims 3 to 5, characterized in that reference position data are assigned to each reference region (3). Method for determining current position data according to claim 2, characterized in that the defined event is the passing of roadside toll infrastructure elements, for example toll gates or support beacons. Method for determining current position data according to claim 7, characterized in that reference data are assigned to each toll infrastructure element. Method for determining current position data according to Claim 2, characterized in that the defined event is the occurrence of a defined sequence of determined current position data (4). Method for determining current position data according to one of Claims 1 to 9, characterized in that the conversion to corrected current position data (7) takes place for a fixed period of time. Method for determining current position data according to one of Claims 1 to 9, characterized in that the conversion to corrected actual position data (7) takes place for a defined number of distance units. Method for determining current position data according to one of Claims 1 to 9, characterized in that the conversion to corrected position data (7) takes place until conformity or non-compliance thereof with a defined area (1) of the electronically stored geodata occurs. Toll detection system comprising mobile detection units (OBUs) for arrangement in a vehicle, each mobile detection unit having at least one location unit for the purpose of determining current position data by means of position information radiating devices, preferably satellites, and a processor unit containing the determined current position data in the mobile detection unit stored geodata, which comprise at least a portion of the road network of a geographical area, for the purpose of current position determination of a vehicle, characterized in that an offset (6) from the comparison of the determined current position data and reference position data can be determined by means of processor unit, with which all the following, determined corrected current position data (4) and to be corrected current position data (7) are convertible. Mobile detection unit comprising at least one localization unit and a processor unit of a toll collection system according to claim 13.

Images