BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a method, a device and a system for providing correction data for position determination, in particular for a differential global navigation satellite system (differential GNSS or DGNSS).

Navigation apparatuses for motor vehicles often use a global navigation satellite system (GNSS), such as for example the global positioning system (GPS), the global orbiting navigation satellite system (GLONASS), Galileo or Beidou, for determining respective position and possibly also course and speed.

A GNSS, for example GPS, provides for example positioning accuracy of the order of magnitude of 10 meters. The position determination of GNSS is based on measuring distances from the receiver to a plurality of satellites. The distance is measured indirectly by way of the propagation time of the signals from the satellites to the receiver. Use is in this case made of the fact that the speed at which the signals propagate is ideally constant and known. However, in practice, certain inaccuracies arise because the speed of the signals varies slightly due to atmospheric interference. Reflections and scattering of the radio signals from buildings, as well as shading of individual satellites depending on the surroundings (for example horizon, buildings, etc.) may also disadvantageously influence the accuracy of position determination. Errors in the position determination may primarily be caused by strong attenuation, by reflection of some or all of the GNSS signals and by reception from too few satellites.

A differential global positioning system (differential GPS or DGPS) increases accuracy of GPS navigation by providing correction data, also called correction signals or difference signals. As things stand, fixed GPS receivers, so-called reference stations, are used in DGPS. For each satellite, the effective propagation times of the signals to the receiver are able to be determined highly accurately from the deviation between the actual and the received position. The reference station transmits the differences between the theoretical and the actual signal propagation times to the GPS receivers in the surroundings, for example within a radius of up to 10 km. The DGPS receivers use these indications of difference as a correction signal, by way of which the position of the receiver is able to be calculated accurately. The accuracy of the GPS signal is able to be increased significantly by using differential GPS correction data. Accuracies in the region of centimeters are therefore possible in corresponding DGPS receivers.

The shorter the distance between the corresponding DGPS receivers and the reference station, the higher the accuracy of the position determination using the correction data.

The object on which the invention is based is that of providing a method and a corresponding device and a system for providing correction data for position determination, these enabling correction data to be provided at low cost.

The invention is distinguished, according to a first and a second aspect, by a method and a corresponding device for providing correction data for position determination. In this case, first position data are determined and/or provided for a vehicle depending on a global satellite navigation system reception signal, GNSS reception signal, wherein a GNSS receiver or DGNSS receiver is arranged in the vehicle in order to receive the GNSS reception signal, and the first position data are determined when the vehicle is situated in a charging position of a predefined charging station. Furthermore, second position data are determined and/or provided, wherein the second position data comprise information representative of a global position of the predefined charging station. Correction data are determined depending on the first position data and the second position data. The correction data are provided for at least one further apparatus in order to determine a position of the at least one further apparatus.

The correction data are preferably provided for highly accurate position determination. Position determination for an object should be considered to be highly accurate if a position that is determined for the object deviates by less than 10 m, in particular by less than 1 m, from an actual position of the object.

Since the respective charging stations do not change their position in relation to the global world coordinates following installation, their position is able to be determined highly accurately upon or shortly after installation. With this knowledge, whenever a vehicle is charging above or at the charging station, correction data are able to be derived by way of the first position data and second position data, which correction data are used by other DGNSS receivers, which are situated in the vicinity (up to around 20 km away) of the charging vehicle, for highly accurate position determination. In particular, the first and second position data and/or the correction data may be determined and/or provided multiple times during a charging procedure. The charging station therefore functions together with the charging vehicle as a reference GNSS receiver.

The correction data may comprise and/or represent a difference signal, wherein the difference signal is determined by determining a difference between a measured and/or determined distance of the vehicle and the actual distance of the vehicle to each individual satellite. To this end, the absolute position of the vehicle or of the charging station and the satellite signal or signals received by the GNSS receiver are necessary. The orbit data are contained in the satellite reception signals. It is thus possible to determine an error in relation to each satellite. The calculation may in this case be performed in the charging station and/or in the vehicle and/or on the server. Missing data must in this case respectively be transmitted to the unit that is to be determined.

Advantageously, the correction data are able to be determined highly accurately. The correction data may be used for differential GNSS, in particular for a differential GPS. As an alternative or in addition, the correction data may be provided for further services. Further vehicle functions, for example autonomous driving, may be improved on the basis of the provided correction data. As an alternative or in addition, the correction data may be offered and sold online. Only a very slight additional hardware expenditure is required. For one implementation, it is necessary to provide sufficient computational power, sufficient storage space and a back-end system. Installing additional reference GPS receivers or reference GNSS receivers is able to be dispensed with. In particular for the charging stations, it is not necessary to take any additional actions. The hardware components and/or software components that are necessary for communication between the charging station and the vehicle, for example an authentication procedure having an identification ID, is in most cases already provided in connection with data-based coupling of the vehicle to the charging station (for example via WLAN) in connection with a billing system.

The global position data may also be referred to as absolute positioning data.

The predefined charging station is in particular a charging station that is or has been traveled to by a vehicle driver in order to charge an energy store of his vehicle.

In one advantageous refinement according to the first and second aspect, the second position data are determined depending on a global position of the predefined charging station and at least one further item of distance information in relation to the vehicle. This has the advantage that the second position data are able to more accurately characterize an actual position of the vehicle. The item of distance information in particular represents a distance between the predefined charging station and the vehicle.

In a further advantageous refinement according to the first and second aspect, the GNSS receiver or DGNSS receiver of the vehicle has a GNSS antenna. Furthermore, the vehicle has a charging apparatus for charging an energy store of the vehicle, and the at least one item of distance information comprises a distance between the charging apparatus and the GNSS antenna. This makes it possible to take into account specific dimensions of the vehicle when providing the second position data.

In a further advantageous refinement according to the first and second aspect, the predefined charging station comprises a primary coil of an inductive charging system, wherein the primary coil of the inductive charging system is arranged so as to be stationary, and the charging apparatus of the vehicle forms a secondary coil of the inductive charging system. Such a charging station or such a charging system has the advantage that it is possible to determine a relative position of the vehicle in relation to the global position of the charging station with high accuracy and without additional hardware expenditure. The position of the primary coil is understood in particular to be the global position of the predefined charging station.

In a further advantageous refinement according to the first and second aspect, the at least one item of distance information represents a recorded offset between the primary coil and the secondary coil, the offset being recorded when the vehicle is situated in the charging position of the predefined charging station, and the offset representing a distance between the secondary coil and a predefined reference point in relation to the primary coil. This makes it possible to be able to determine the position of the GNSS antenna of the vehicle in relation to the primary coil of the charging station to within an accuracy of a few centimeters.

In a further advantageous refinement according to the first and second aspect, correction data are in each case determined for a predefined area that has a multiplicity of charging stations that are traveled to by various vehicles and/or at various times in order to charge the vehicles. The correction data are in each case stored so as to be assigned to predefined regions of the area and/or assigned to predefined time ranges. Depending on a position of a correction data receiver and/or depending on a current time at which the correction data are requested, the correction data are selected from the multiplicity of correction data for the correction data receiver and transmitted to the correction data receiver.

This advantageously makes it possible, when there is sufficient distribution of the charging stations and sufficient residence time of the vehicles in the charging positions of the charging stations, to make the correction data available for the entire area with sufficient accuracy. By using a dense network of charging stations, the correction data are able to be determined and provided specifically for very small regions of the area, as a result of which accuracy of the position determinations is able to be increased. A central server structure may network the charging stations. The correction data are stored, in particular “merged”, in one or more servers. By way of example, the correction data are averaged between a plurality of adjacent manned charging stations.

In a further advantageous refinement according to the first and second aspect, a global position of a further charging station is determined depending on the correction data that are provided depending on a region in which the further charging station is arranged, and global position data for a further vehicle that are determined for the further vehicle depending on a GNSS reception signal when the further vehicle is situated in a charging position of the further charging station, wherein a GNSS receiver or DGNSS receiver is arranged in the further vehicle in order to receive the GNSS reception signal. The position of the further charging station is therefore able to be determined highly accurately, and the charging station is able to be used as a further network element of a charging station network that makes correction data available for the predefined area.

Using the GNSS antenna of the vehicle has the advantage that the antenna is arranged in the vehicle roof in a manner optimized for reception. Better reception is therefore possible than if the antenna is arranged in the charging station, in particular in the immediate vicinity of the primary coil. The charging station may thus be adopted as a destination, in particular a “precise” destination, in the navigation.

In a further advantageous refinement according to the first and second aspect, the further charging station has a primary coil, arranged so as to be stationary, for an inductive charging system. The second vehicle has a secondary coil for the inductive system. The global position of the further charging station is determined depending on a recorded offset between the primary coil and the secondary coil when the second vehicle is situated in the charging position of the further charging station. This makes it possible to determine the global position of the further charging station very precisely.

In a further advantageous refinement according to the first and second aspect, a trajectory for autonomously driving and/or parking a further vehicle is determined depending on the provided correction data. The trajectory is thus able to be determined highly accurately. The trajectory may be determined by a back-end server and transmitted to the further vehicle and/or the trajectory may be determined by the further vehicle depending on the correction data transmitted to the further vehicle. This allows very precise travel to the charging station. In addition to increased manual comfort, autonomous location and parking above the charging station is in particular also possible. An indication of distance (vehicle-charging station) may be indicated from any desired distance. Obstacles between the vehicle and the charging station do not have any influence.

In a further advantageous refinement according to the first and second aspect, the trajectory is determined depending on satellite-assisted position data that are provided for the further vehicle by way of a GNSS receiver.

In a further advantageous refinement according to the first and second aspect, the trajectory is determined depending on odometry position data that are determined by way of an odometry system of the further vehicle. This has the advantage that the trajectory is able to be determined highly accurately even in regions in which no satellite signals are able to be received.

In a further advantageous refinement according to the first and second aspect, depending on at least one predefined operating variable for the respective charging stations, it is determined whether correction data in the predefined area are available with a predefined accuracy for all positions of the area and/or in which partial areas of the area correction data are not available with a predefined accuracy for all positions of the area. It is thus easily able to be checked whether and where further charging stations have to be installed in the predefined area in order to be able to provide the correction data with sufficient accuracy with complete coverage in the predefined area.

The at least one operating variable may be representative of a charging activity of the respective charging station and/or be representative of a time of a good signal quality of the individual coils of the charging stations.

In a further advantageous refinement according to the first and second aspect, when an additional charging station is newly installed, it is determined, depending on the at least one operating variable of charging stations in the predefined region in which the additional charging station is arranged, whether the correction data for the region meet a predefined accuracy requirement for position determination of the charging station. This has the advantage that it is easily able to be decided how the global position of the charging station should be determined.

The invention is distinguished, according to a third aspect, by a system for providing correction data for position determination, having at least one charging station, at least one vehicle and a device according to the second aspect. The at least one charging station is designed to transmit a global position of the charging station to the at least one vehicle. The at least one vehicle is designed to determine first position data for the vehicle depending on a global satellite navigation system reception signal, GNSS reception signal, wherein a GNSS receiver or DGNSS receiver is arranged in the vehicle in order to receive the GNSS reception signal, and the first position data are determined when the vehicle is situated in a charging position of a predefined charging station. The at least one vehicle is furthermore designed to transmit the first position data to the device. The at least one vehicle is furthermore designed to determine second position data depending on the global position data of the at least one charging station and to transmit the second position data to the device.

Advantageous refinements of the second aspect also apply in this case to the third aspect.

Exemplary embodiments of the invention are explained below with reference to the schematic drawings.

Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.

