System and Method for Map Matching GNSS Positions of a Vehicle

Abstract

A computer-implemented method and system for map matching Global Navigation Satellite System (GNSS) positions of a vehicle with location information of a digital map, including map matching the determined distance between two respective detected consecutive GNSS positions of the vehicle with a route length between the two respective consecutive GNSS positions of the vehicle on the digital map.

Claims

1-12. (canceled)

13. A computer-implemented method for map matching Global Navigation Satellite System (GNSS) positions of a vehicle with location information from a digital road map, the method comprising: capturing GNSS positions of the vehicle along a route of the vehicle; recording a distance between two captured, successive GNSS positions of the vehicle, which distance is determined using a vehicle sensor; and map matching the distance between the two captured, successive GNSS positions of the vehicle with a route length between the two captured, successive GNSS positions of the vehicle in the digital road map.

14. The computer-implemented method according to claim 13, further comprising determining the distance between the two captured, successive GNSS positions of the vehicle using a wheel speed sensor.

15. The computer-implemented method according to claim 13, wherein the map matching is carried out in real time, after recording a journey or after recording a journey section using a computing device inside the vehicle and/or a server outside the vehicle, and wherein a time stamp is assigned to each captured GNSS position of the vehicle.

16. The computer-implemented method according to claim 15, further comprising: periodically transmitting the GNSS positions and a current speed and/or a current average speed of a plurality of vehicles to the server outside the vehicle; using, by the server outside the vehicle, the GNSS positions and the current speed and/or the current average speed of the plurality of vehicles to calculate traffic information; and making the traffic information available to the plurality of vehicles.

17. The computer-implemented method according to claim 16, wherein using the current speed and/or the current average speed of the plurality of vehicles to calculate traffic information further comprises calculating an expected time of arrival and/or average speeds of road sections.

18. The computer-implemented method according to claim 15, further comprising: capturing hazard data by the vehicle sensor or at least one other vehicle sensor, wherein the hazard data relates to at least one of a slippery road, a traffic accident, and/or airbag activation; and transmitting, to the server outside the vehicle, the hazard data and the GNSS position of the vehicle, wherein the server outside the vehicle carries out map matching of the hazard data and makes these data available to other vehicles whose planned route goes through a recognized hazard.

19. The computer-implemented method according to claim 15, further comprising: recording a personal route of a driver as a sequence of GNSS positions; and transmitting, to the server outside the vehicle, the personal route, wherein the server outside the vehicle carries out map matching of the sequence of GNSS positions, transmits a learned personal route of the driver to the vehicle, and suggests route guidance for the learned personal route to the driver at predefined times.

20. The computer-implemented method according to claim 13, further comprising: calculating a probability density for a transition from matching candidate c.sub.t,i in a time step t to matching candidate c.sub.t+1,j in a time step t+1 using the following equation: $p\left(r,d\right)=\frac{1}{\sigma \sqrt{2\pi }}{e}^{-\frac{1}{2}\left(\frac{r-d}{\sigma }\right)2}$ where r is a length of the quickest route between c.sub.t,i and c.sub.t+1,j; d is a distance covered between the time step t and the time step t+1; p(r, d) is the probability density, where σ is a standard deviation of the captured GNSS positions.

21. The computer-implemented method according to claim 20, wherein the standard deviation σ is determined using a root of a sample variance of a sample of GNSS positions and vehicle sensor distance measurements for a plurality of journeys, wherein driven routes of the plurality of journeys are known.

22. The computer-implemented method according to claim 20, wherein transitions between matching candidates are excluded in response to the route length of the quickest route between the matching candidates being shorter or longer at least by a predefined factor than the distance determined using the vehicle sensor.

23. The computer-implemented method according to claim 20, further comprising: using the distance between the two captured, successive GNSS positions of the vehicle to check a plausibility of map matching results, wherein a length of a quickest route between two adjacent matched GNSS positions is calculated, wherein at least one of the two determined GNSS positions of the vehicle is classified as implausible in response to the length of the quickest route being shorter or longer by at least a predefined factor than the distance between the two captured, successive GNSS positions.

24. A system for map matching Global Navigation Satellite System (GNSS) positions of a vehicle with location information from a digital road map, comprising: at least one computing device configured to: capture GNSS positions of the vehicle along a route of the vehicle; record a distance between two captured, successive GNSS positions of the vehicle, which distance is determined using a vehicle sensor; and map match the distance between the two captured, successive GNSS positions of the vehicle with a route length between the two captured, successive GNSS positions of the vehicle in the digital road map.

25. The system according to claim 24, wherein the at least one computing device is further configured to: record a journey or a journey section; perform the map matching in real time, after recording the journey or the journey section, wherein a time stamp is assigned to each captured GNSS position of the vehicle.

26. The system according to claim 25, wherein the at least one computing device is further configured to: periodically receive the GNSS positions and a current speed and/or a current average speed of a plurality of vehicles; use the GNSS positions and the current speed and/or the current average speed of the plurality of vehicles to calculate traffic information; and make the traffic information available to the plurality of vehicles.

27. The system according to claim 25, wherein the at least one computing device is further configured to: capture hazard data by the vehicle sensor or at least one other vehicle sensor, wherein the hazard data relates to at least one of a slippery road, a traffic accident, and/or airbag activation; and perform map matching of the hazard data and make these data available to other vehicles whose planned route goes through a recognized hazard.

28. The system according to claim 25, wherein the at least one computing device is further configured to: record a personal route of a driver as a sequence of GNSS positions; perform map matching of the sequence GNSS positions; and transmit a learned personal route of the driver to the vehicle and suggest route guidance for the learned personal route to the driver at predefined times.

29. The system according to claim 24, wherein the at least one computing device is further configured to: calculate a probability density for a transition from matching candidate c.sub.t,i in a time step t to matching candidate c.sub.t+1,j in a time step t+1 using the following equation: $p\left(r,d\right)=\frac{1}{\sigma \sqrt{2\pi }}{e}^{-\frac{1}{2}\left(\frac{r-d}{\sigma }\right)2}$ where r is a length of the quickest route between c.sub.t,i and c.sub.t+1,j; d is a distance covered between the time step t and the time step t+1; p(r, d) is the probability density, where σ is a standard deviation of the captured GNSS positions.

30. The system according to claim 29, wherein the at least one computing device is further configured to: exclude transitions between matching candidates in response to the route length of the quickest route between the matching candidates being shorter or longer at least by a predefined factor than the distance determined using the vehicle sensor.

31. The system according to claim 29, wherein the at least one computing device is further configured to: use the distance between the two captured, successive GNSS positions of the vehicle to check a plausibility of map matching results; calculate a length of a quickest route between two adjacent matched GNSS positions; and classify at least one of the two determined GNSS positions of the vehicle as implausible in response to the length of the quickest route being shorter or longer by at least a predefined factor than the distance between the two captured, successive GNSS positions.

32. A non-transitory computer-readable data storage medium having stored thereon a computer program that, when executed by at least one computing device, cause the at least one computing device to perform a method comprising: capturing Global Navigation Satellite System (GNSS) positions of a vehicle along a route of the vehicle; recording a distance between two captured, successive GNSS positions of the vehicle, which distance is determined using a vehicle sensor; and map matching the distance between the two captured, successive GNSS positions of the vehicle with a route length between the two captured, successive GNSS positions of the vehicle in a digital road map.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIG. 1 shows a schematic illustration of a system for map matching GNSS positions of a vehicle with location information from a digital road map according to one preferred embodiment of the invention;

[0038] FIG. 2 shows a schematic illustration of a digital road map for illustrating the method for map matching GNSS positions of the vehicle with location information from the digital road map according to the preferred embodiment of the invention; and

[0039] FIG. 3 shows a flowchart of a computer-implemented method for map matching GNSS positions of a vehicle with location information from the digital road map.

DETAILED DESCRIPTION

[0040] The system for map matching GNSS positions of the vehicle 1 with location information from a digital road map, as shown in FIG. 1, comprises the vehicle 1 having means 20 for capturing GNSS positions of the vehicle 1 along a route of the vehicle 1. Within the scope of the present embodiment, GPS is the preferred form of GNSS.

[0041] The system also comprises means 22 for recording a distance between in each case two captured, successive GNSS positions of the vehicle 1, which is determined using a vehicle sensor 10, in particular a wheel speed sensor. The system also comprises means 24 for map matching the determined distance between the in each case two captured, successive GNSS positions of the vehicle 1 with a route length between the in each case two captured, successive GNSS positions of the vehicle in the digital road map.

[0042] The map matching is preferably carried out in real time using a computing device 12 inside the vehicle and a server 14 outside the vehicle, wherein a time stamp is assigned to each captured GNSS position of the vehicle 1.

[0043] Alternatively, the map matching can be carried out, for example, after recording a journey or after recording a journey section using the computing device 12 inside the vehicle and/or the server 14 outside the vehicle.

[0044] As illustrated in FIG. 1, the means 24′ for map matching may alternatively be arranged on the server 14 outside the vehicle, for example.

[0045] The vehicle 1 also has further sensors which are not illustrated in FIG. 1, inter alia a speed sensor, a sensor for detecting airbag activation, sensors for detecting slippery roads and/or camera sensors.

[0046] The server 14 outside the vehicle has a receiving unit which is not illustrated in FIG. 1. On the basis of the data received from the vehicle 1, the server 14 outside the vehicle also calculates traffic information, calculates hazard warnings and/or learns a personal route of the driver. The calculated data are then made available to further vehicles in a vehicle fleet.

[0047] FIG. 2 shows a schematic illustration of a digital road map for illustrating the method for map matching GNSS positions of the vehicle with location information from the digital road map according to the preferred embodiment of the invention.

[0048] In the present illustration, three GNSS positions G1, G2, G3 of the vehicle 1 are represented in the digital road map K by way of example. Since the GNSS positions G1, G2, G3 of the vehicle 1 are depicted in the road map K in a manner offset with respect to respective roads of the digital road map K in the present exemplary embodiment, map matching of the GNSS positions G1, G2, G3 of the vehicle 1 with location information from the digital road map K must be carried out in order to calculate a movement path of the vehicle 1.

[0049] A first GNSS position G1 of the vehicle 1 is in the vicinity of the three road sections or location information items P1a, P1b, P1c, for example.

[0050] A second GNSS position G2 of the vehicle 1 is likewise in the vicinity of two road sections or location information items P2a, P2b. In addition, a third GNSS position G3 of the vehicle 1 is in the vicinity of two roads or road sections or location information items P3a, P3b.

[0051] The GNSS positions G1, G2, G3 of the vehicle 1 along a route of the vehicle 1 are therefore captured first of all. A distance E1, E2 between in each case two captured, successive GNSS positions of the vehicle 1, for example a distance E1 between the first GNSS position G1 and the second GNSS position G2, which is determined using the vehicle sensor, in particular the wheel speed sensor, is then recorded.

[0052] The determined distance E1 between the first GNSS position G1 and the second GNSS position G2 of the vehicle 1 is then compared with a first route length L1 in the digital road map K.

[0053] A second distance E2 between the second GNSS position G2 and the third GNSS position G3 is likewise captured and a determined distance E2 between the second GNSS position G2 and the third GNSS position G3 is compared with a route length L2 in the digital road map K.

[0054] In addition, a probability density for a transition from matching candidate c.sub.t,i in a time step t to matching candidate c.sub.t+1,j in a time step t+1 is calculated using the following equation:

[00002]$p\left(r,d\right)=\frac{1}{\sigma \sqrt{2\pi }}{e}^{-\frac{1}{2}\left(\frac{r-d}{\sigma }\right)2}$

[0055] where r is the length of the quickest route between c.sub.t,i and c.sub.t+1,j; d is the distance covered between the times t and t+1; p or p(r, d) is the probability density, where σ is the standard deviation of the captured GNSS positions, and where i and j are numerical placeholders for ground truth road segments or location information, wherein the location information is denoted P1a, P1b, P1c, P2a, P2b, P3a, P3b in the present embodiment.

[0056] In the present embodiment, the matching candidates are denoted M1a, M1b, M1c, M2a, M2b, M3a, M3b. The probability density for the transition from matching candidate c.sub.t,i in a time step t to matching candidate c.sub.t+1,j in a time step t+1 could therefore denote, for example, the probability density for the transition from matching candidate M1c to matching candidate M2b.

[0057] A standard deviation σ is determined using the root of a sample variance of a sample of GNSS positions G1, G2, G3 and vehicle sensor distance measurements for a plurality of journeys, the driven route of which is known.

[0058] Transitions between matching candidates M1a, M1b, M1c, M2a, M2b, M3a, M3b are excluded if the route length L1, L2 of the quickest route between the matching candidates M1a, M1b, M1c, M2a, M2b, M3a, M3b is shorter or longer by a predefined factor than the distance E1, E2 determined using the vehicle sensor 10.

[0059] GNSS positions G1, G2, G3, a current speed and/or a current average speed of a multiplicity of vehicles is/are periodically transmitted to the server 14 outside the vehicle and is/are used by the server 14 outside the vehicle to calculate traffic information, in particular an expected time of arrival and/or average speeds of road sections, and to make it available to the multiplicity of vehicles.

[0060] Hazard data captured by vehicle sensors, in particular relating to a slippery road, a traffic accident and/or airbag activation, are transmitted to the server 14 outside the vehicle together with the GNSS position G1, G2, G3 of the vehicle 1, wherein the server 14 outside the vehicle carries out map matching of the hazard data and makes these data available to vehicles 1 whose planned route goes through a recognized hazard.

[0061] A personal route of a driver is recorded as a sequence of GNSS positions G1, G2, G3 and is transmitted to the server 14 outside the vehicle.

[0062] The server 14 outside the vehicle carries out map matching of the GNSS positions G1, G2, G3, transmits the learned personal route of the driver to the vehicle 1 and suggests route guidance for the learned personal route to the driver at predefined times.

[0063] The distance E1, E2 between in each case two captured, successive GNSS positions G1, G2, G3 of the vehicle 1, which is determined using the vehicle sensor 10, is used to check the plausibility of map matching results.

[0064] A length of the quickest route between two adjacent matched GNSS positions G1, G2, G3 is calculated in each case. At least one of the two determined GNSS positions G1, G2, G3 of the vehicle 1 is classified as implausible if the length is shorter or longer by a predefined factor than the distance E1, E2 determined using the vehicle sensor 10.

[0065] FIG. 3 shows a flowchart of a computer-implemented method for map matching GNSS positions of a vehicle with location information from the digital road map.

[0066] The method comprises capturing S1 GNSS positions G1, G2, G3 of the vehicle 1 along a route of the vehicle 1.

[0067] The method also comprises recording S2 a distance E1, E2 between in each case two captured, successive GNSS positions G1, G2, G3 of the vehicle 1, which is determined using a vehicle sensor 10, in particular a wheel speed sensor.

[0068] The method moreover comprises map matching S3 the determined distance E1, E2 between the in each case two captured, successive GNSS positions G1, G2, G3 of the vehicle 1 with a route length L1, L2 between the in each case two captured, successive GNSS positions G1, G2, G3 of the vehicle 1 in the digital road map K.

[0069] The term “vehicle” comprises automobiles, trucks, buses, motorhomes, motorcycles, etc. which are used to convey persons, goods, etc.

[0070] In particular, the term comprises motor vehicles for conveying persons. Additionally or alternatively, a hybrid or electric vehicle according to embodiments may be a pure electric vehicle (BEV) or a plug-in hybrid vehicle (PHEV). However, other drive forms can also be used, for example in the form of a diesel-powered or gasoline-powered vehicle. The vehicle may also be in the form of a rail vehicle.

[0071] Although the invention has been explained and illustrated more specifically in detail by means of preferred exemplary embodiments, the invention is not restricted by the disclosed examples and other variations can be derived therefrom by a person skilled in the art without departing from the scope of protection of the invention.

[0072] It is therefore clear that there are a multiplicity of possible variations. Embodiments mentioned by way of example are only examples which should not be interpreted in any way as a limitation of the scope of protection, of the possible uses or of the configuration of the invention, for instance.

[0073] Rather, the preceding description and the description of the figures make it possible for a person skilled in the art to specifically implement the exemplary embodiments, in which case a person skilled in the art with knowledge of the disclosed concept of the invention can make various modifications, for example in terms of the function or the arrangement of individual elements mentioned in an exemplary embodiment, without departing from the scope of protection which is defined by the claims and their legal equivalents, for instance more in-depth explanations in the description.

[0074] The map matching S3 can alternatively be carried out, for example, between two arbitrary GNSS positions G1, G2, G3 of the vehicle 1 with a route length L1, L2 between in each case two corresponding arbitrary GNSS positions G1, G2, G3 of the vehicle 1 in the digital road map K.