Map data management device and map data management method

Abstract

A map update control unit (13) of a map data management device (10) of the present invention predicts a grid for which map data is requested from a map application (23), and identifies a grid whose map data stored in a map database (11) is not the latest among the grids predicted to request map data as a grid requiring update. If the map data of the grid requiring update can be updated before the map data of the grid requiring update is requested from the map application (23), the map update control unit (13) performs a first map update process for quickly updating the map data of the grid requiring update. If the map data of the grid requiring update can not be updated, the map update control unit (13) performs a second map update process for updating the map data of the grid requiring update when the operation of the map application (23) satisfies a predetermined condition.

Description

Technical Field

[0001] The present disclosure relates to a map data management device that manages update of map data. Background Art

[0002] The practical application of in-vehicle devices, such as car navigation systems, ADAS (Advanced Driver-Assistance Systems), and autonomous driving systems, that execute map applications that utilize map data provided by map databases is progressing. To provide the latest map data to these in-vehicle devices, it is desirable for them to have a function that downloads and obtains the latest map data from a map distribution server and updates the map data stored in the in-vehicle device's map database.

[0003] Generally, map databases store map data for each grid-like area (referred to as a "grid") obtained by dividing a map into grids. For example, Patent Document 1 below discloses a map data management device that efficiently updates map data by prioritizing map data for high-priority grids, such as grids surrounding specific POIs (Points of Interest) such as a user's home and grids encompassing the route from a vehicle's current location to a destination.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2012-123418 Summary of the Invention

[0007] Technical problem to be solved by the invention

[0008] It's desirable for map data management devices to always provide map applications with the latest map data. However, if determining the grids requiring map data updates takes time, if the grids requiring map data updates are densely packed, or if vehicles are traveling at high speeds, map data updates may not keep up with map data requests from map applications, resulting in the map applications being provided with outdated, unupdated map data. If a mix of old and latest map data is provided to a map application, the map application may not function properly. In recent years, high-precision map data, including road shape information for each lane, has become available. Downloading this data takes time, making it easy for map data updates to be delayed.

[0009] The present disclosure is made to solve the above-mentioned problem, and an object thereof is to provide a map data management device that prevents old map data and the latest map data from being mixed and provided to a map application.

[0010] Technical means for solving technical problems

[0011] A map data management device according to a first aspect of the present disclosure includes: a map database storing map data for each grid obtained by dividing a map into grids; a map access unit providing the map data stored in the map database to the map application in response to a request from the map application; an update map data acquisition unit acquiring update map data, which is the latest map data for each grid, from a map distribution server; and a map update control unit updating the map data stored in the map database using the update map data. The map update control unit predicts grids for which map data will be requested from the map application, identifies, among the grids predicted to be requested for map data, grids for which map data stored in the map database is not the latest, as grids requiring update; and, if the map data for the grid requiring update can be updated before the map data for the grid requiring update is requested from the map application, performs a first map update process for quickly updating the map data for the grid requiring update; and, if the map data for the grid requiring update cannot be updated before the map data for the grid requiring update is requested from the map application, performs a second map update process for updating the map data for the grid requiring update when an operation of the map application satisfies a predetermined condition.

[0012] A map data management device according to a second embodiment of the present disclosure includes: a map database storing map data for each grid obtained by dividing a map into grids; a map access unit providing the map application with the map data stored in the map database in response to a request from the map application; an update map data acquisition unit acquiring update map data, which is the latest map data for each grid, from a map distribution server; and a map update control unit updating the map data stored in the map database using the update map data, wherein the map data stored in the map database includes high-precision map data including road shape information for each lane. The map update control unit predicts as a grid for which map data is requested from the map application a grid for which high-precision map data is present, or a grid for which high-precision map data is present, connected from a grid to which a current position belongs, or a grid for which high-precision map data is present, connected from a road within the grid to which the current position belongs. Among the grids predicted to be for which map data is requested, the map update control unit determines as a grid requiring update a grid for which map data stored in the map database is not the latest, and updates the map data of the grid requiring update.

[0013] Effects of the Invention

[0014] The map data management device according to the first aspect of the present disclosure does not immediately update the map data of the mesh requiring update, but performs the update afterward, if the map data of the mesh requiring update cannot be updated before the map data of the mesh requiring update is requested from the map application. This prevents the map data of the mesh requiring update from being mixed with old map data and the latest map data from being provided to the map application.

[0015] The map data management device according to the second aspect of the present disclosure predicts the meshes for which map data will be requested from a map application based on the connections of meshes containing high-precision map data. This reduces the probability of map data being late for updating. Consequently, it prevents a mix of old and latest map data from being provided to map applications.

[0016] The objects, features, modes and advantages of the present disclosure will become more apparent from the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a block diagram showing the configuration of a map data management device according to the first embodiment.

[0018] Figure 2 is a flowchart showing the operation of the map application.

[0019] Figure 3 is a diagram showing an example of a grid dividing a map.

[0020] Figure 4 1 is a diagram showing an example of a map represented by map data.

[0021] Figure 5 This is a diagram for explaining map data provided to a map application.

[0022] Figure 6 This is a diagram for explaining map data provided to a map application.

[0023] Figure 7 This is a diagram for explaining map data provided to a map application.

[0024] Figure 8 FIG. 1 is a diagram showing an example of a mesh predicted to request map data and a mesh requiring update.

[0025] Figure 9 is a diagram showing an example of whether data needs to be updated.

[0026] Figure 10 1 is a diagram showing an example of a situation in which map data can be updated before map data is requested from a map application.

[0027] Figure 11 is a diagram illustrating an example of a situation in which map data cannot be updated before map data is requested from a map application.

[0028] Figure 12 This is a flowchart showing the operation of the map data management device according to the first embodiment.

[0029] Figure 13 This is a block diagram showing a modified example of the map data management device according to the first embodiment.

[0030] Figure 14 This is a flowchart showing a modified example of the operation of the map data management device according to the first embodiment.

[0031] Figure 15 This is a flowchart showing a modified example of the operation of the map data management device according to the first embodiment.

[0032] Figure 16 This is a block diagram showing the configuration of a map data management device according to the second embodiment.

[0033] Figure 17 FIG. 1 is a diagram showing an example of a grid in which high-precision map data exists.

[0034] Figure 18 is a diagram showing an example of mesh connection management data.

[0035] Figure 19 FIG. 1 is a diagram showing an example of a mesh predicted to request map data and a mesh requiring update.

[0036] Figure 20 This is a flowchart showing the operation of the map data management device according to the second embodiment.

[0037] Figure 21 FIG. 1 is a diagram showing an example of a mesh predicted to request map data and a mesh requiring update.

[0038] Figure 22 FIG. 1 is a diagram showing an example of a mesh predicted to request map data and a mesh requiring update.

[0039] Figure 23 FIG. 1 is a diagram showing an example of a mesh predicted to request map data and a mesh requiring update.

[0040] Figure 24 FIG. 1 is a diagram showing an example of a mesh predicted to request map data and a mesh requiring update.

[0041] Figure 25This is a block diagram showing the configuration of a map data management device according to the third embodiment.

[0042] Figure 26 This is a block diagram showing the configuration of a map data management device according to a fourth embodiment.

[0043] Figure 27 This is a flowchart showing the operation of the map application in the fourth embodiment.

[0044] Figure 28 This is a flowchart showing the operation of the map data management device according to the fourth embodiment.

[0045] Figure 29 This is a diagram showing a hardware configuration example of a map data management device.

[0046] Figure 30 This is a diagram showing a hardware configuration example of a map data management device. DETAILED DESCRIPTION

[0047] <Implementation Method 1>

[0048] Figure 1 1 is a block diagram showing the structure of the map data management device 10 according to the first embodiment. Figure 1 As shown, the map data management device 10 is incorporated into an onboard device 20 including a communication device 21, a positioning unit 22, a map application 23, and a pre-read map data storage unit 24. Hereinafter, a vehicle equipped with the onboard device 20 is referred to as a "host vehicle."

[0049] However, the map data management device 10 does not necessarily need to be built into the vehicle-mounted device 20, and may be a portable device such as a mobile phone or smartphone that is externally connected to the vehicle-mounted device 20. In addition, part of the functions of the map data management device 10 may be implemented on an external server that can communicate with the map data management device 10.

[0050] The communication device 21 is a device used by the in-vehicle device 20 to communicate with the outside world. The map data management device 10 can use the communication device 21 to access the map distribution server 30, which distributes the latest map data. The communication device 21 can be a dedicated communication device for the in-vehicle device 20 or a general-purpose communication device such as a mobile phone or smartphone.

[0051] The positioning unit 22 measures the current position of the vehicle using positioning signals received from the GNSS (Global Navigation Satellite System), outputs from vehicle sensors (such as a speed sensor and a direction sensor), and map data acquired from the map data management device 10 .

[0052] The map application 23 is a functional block implemented by programs executed by the in-vehicle device 20. It implements functions such as navigation, ADAS, and autonomous driving. The map application 23 requests the map data required for these functions from the map data management device 10 and uses the map data provided by the map data management device 10 to implement the aforementioned functions.

[0053] Although not shown in the figure, the map application 23 acquires information necessary for various functions from the vehicle's surrounding sensors, vehicle status sensors, and other sensors. Furthermore, when implementing ADAS and autonomous driving functions, the map application 23 can control the vehicle's driving control systems, such as the steering wheel, accelerator, and brakes. When the map application 23 implements navigation, connected to the in-vehicle device 20 are an input device for user input of destinations, a display device that displays the intended route to the user, and an audio output device that provides route guidance to the user.

[0054] The pre-read map data storage unit 24 is a temporary memory that stores map data provided from the map data management device 10 to the map application 23. As the pre-read map data storage unit 24, a cache memory that can be accessed at high speed by the map application 23 may be used.

[0055] Here, use Figure 2 The flowchart in FIG2 illustrates the operation of the map application 23. Upon starting operation, the map application 23 obtains the current location of the vehicle from the positioning unit 22 (step S200). Next, the map application 23 requests map data for the grid surrounding the vehicle's current location from the map data management device 10 (step S201). The map application 23 then waits for the requested map data to be stored in the pre-read map data storage unit 24 (step S202).

[0056] If the requested map data is stored in the pre-read map data storage unit 24 ("Yes" in step S202), the map application 23 uses the map data stored in the pre-read map data storage unit 24, that is, the map data provided by the map data management device 10 (step S203). This enables, for example, navigation functions, ADAS functions, and autonomous driving functions.

[0057] The map application 23 repeats the above-described operation until the operation is terminated, for example, by the power supply of the vehicle-mounted device 20 being turned off (until the result is "YES" in step S204).

[0058] Return to Figure 1 The map data management device 10 includes a map database 11 , a map access unit 12 , a map update control unit 13 , an update map data acquisition unit 14 , an update data necessity storage unit 15 , and an update map data storage unit 16 .

[0059] The map database 11 is a storage medium that stores map data for each grid obtained by dividing a map into grids. In the first embodiment, the map data stored in the map database 11 is high-precision map data (hereinafter also referred to as "HD map data") containing road shape information for each lane.

[0060] The map data in the map database 11 is managed in grid units. Specifically, the map data for one grid is managed as a single file. This allows updates to the map data stored in the map database 11 to be performed on a grid-by-grid (i.e., file-by-file) basis. However, there are no restrictions on the management method for the map data in the map database 11. For example, map data for multiple grids can be stored as a single file, or the map data for one grid can be divided into multiple files. Furthermore, there is no restriction on the size of a single grid; for example, a 1 km x 1 km rectangle can be considered a single grid.

[0061] In response to a request from the map application 23, the map access unit 12 provides the map data stored in the map database 11 to the map application 23. In this embodiment, the map data provided to the map application 23 is stored in the pre-read map data storage unit 24, which serves as temporary storage. Specifically, the map data is provided to the map application 23 by storing the map data in the pre-read map data storage unit 24.

[0062] In the first embodiment, the map application 23 requests map data for a 3×3 grid centered on the grid to which the vehicle's current location belongs from the map access unit 12. In this case, the pre-read map data storage unit 24 only needs to have enough storage capacity to store at least 3×3 grids of map data. However, in the present embodiment, the pre-read map data storage unit 24 is capable of storing map data for more than 3×3 grids (e.g., 9×9 or 18×18 grids). Like a ring buffer, if the capacity is full, data written older than the last is overwritten.

[0063] The map data grid requested by the map application 23 at one time is not limited to a 3×3 grid, nor does it need to be rectangular. For example, the map application 23 may request map data for a grid that extends along the road the vehicle is currently traveling on or along the vehicle's planned travel path, or may request map data for a grid that extends further in front of the vehicle (in the direction of travel) than behind it.

[0064] The map update control unit 13 performs processing for updating the map data stored in the map database 11. The update map data acquisition unit 14 uses the communication device 21 to access the map distribution server 30 and downloads and acquires the latest map data from the map distribution server 30 for the map update control unit 13 to use in updating the map data. Hereinafter, the latest map data downloaded from the map distribution server 30 by the update map data acquisition unit 14 is referred to as "update map data."

[0065] The update necessity data storage unit 15 is a storage medium that stores update necessity data. This update necessity data is used to manage, on a grid-by-grid basis, whether the map data stored in the map database 11 requires updating (i.e., whether the map data is up-to-date). In this embodiment, the map update control unit 13 preliminarily (e.g., upon startup of the map data management device 10) compares the map data version for each grid stored in the map database 11 with the map data version for each grid stored in the map distribution server 30 to determine whether the map data for each grid stored in the map database 11 requires updating. The result is then stored as update necessity data in the update necessity data storage unit 15. Preliminary storage of the update necessity data in the update necessity data storage unit 15 reduces the number of times the map update control unit 13 accesses the map distribution server 30 to determine whether the map data requires updating, thereby accelerating processing.

[0066] Furthermore, although the number of visits to the map distribution server 30 increases, the map update control unit 13 may visit the map distribution server 30 each time it needs to confirm whether map data needs to be updated. In this case, the update necessity data storage unit 15 is not required.

[0067] The updated map data storage unit 16 is a storage medium capable of temporarily storing updated map data downloaded by the map update control unit 13 from the map distribution server 30. As will be described in detail later, the updated map data storage unit 16 stores updated map data when the map data stored in the map database 11 cannot be updated in time with the map data request from the map application 23.

[0068] Here, a specific example is given to explain the operation of the map access unit 12. Here, for the sake of simplicity, it is assumed that the map database 11 stores Figure 3 The 16×16 grid shown here represents Figure 4The map data of the map. The 16×16 grids are marked with row and column numbers 0 to F (in hexadecimal notation), and the grid in row i and column j is marked with "ij" as ID (identifier). Hereinafter, the grid in row i and column j (the grid with ID "ij") is marked as "grid M ij ”.

[0069] When the map application 23 starts operating, for example Figure 5 As shown, if the vehicle's position is in grid M 28 The map application 23 requests the map data management device 10 to use the grid M 28 A 3×3 grid centered on M 17 、M 18 、M 19 、M 27 、M 28 、M 29 、M 37 、M 38 、M 39 The map access unit 12 of the map data management device 10 stores the map data of these meshes in the pre-read map data storage unit 24 in response to a request from the map application 23 , and provides the map data to the map application 23 .

[0070] Afterwards, if Figure 6 As shown, if the position of the vehicle is towards the grid M 38 If the map application 23 moves, it requests the map access unit 12 to move the map in the form of a grid M. 38 A 3×3 grid centered on the grid M 27 、M 28 、M 29 、M 37 、M 38 、M 39 、M 47 、M 48 、M 49 At this time, the map access unit 12 needs to provide the map data of these grids to the map application 23, but since the grid M 27 、M 28 、M 29 、M 37 、M 38 、M 39 The map data of the grid M has been provided to the map application 23 (stored in the pre-read map data storage unit 24), so the map access unit 12 only 47 、M 48 、M 49 The map data may be stored in the pre-read map data storage unit 24 .

[0071] Afterwards, if Figure 7As shown, if the position of the vehicle is towards the grid M 37 If the map application 23 moves, it requests the map access unit 12 to move the map in the form of a grid M. 37 A 3×3 grid centered on the grid M 26 、M 27 、M 28 、M 36 、M 37 、M 38 、M 46 、M 47 、M 48 At this time, due to the grid M 27 、M 28 、M 37 、M 38 、M 47 、M 48 The map data of the grid M is already stored in the pre-read map data storage unit 24, so the map access unit 12 only needs to store the grid M 26 、M 36 、M 46 The map data may be stored in the pre-read map data storage unit 24 .

[0072] In this manner, the map access unit 12 does not repeatedly write map data already stored in the pre-read map data storage unit 24 into the pre-read map data storage unit 24 , thereby enabling the map data provision process to be performed to the map application 23 at high speed.

[0073] Next, the operation of the map update control unit 13 will be described using a specific example. Before updating map data, the map update control unit 13 predicts the meshes for which map data will be requested from the map application 23. In this embodiment, the map update control unit 13 predicts meshes within a predetermined range, including the mesh to which the vehicle's planned travel route belongs, as the meshes for which map data will be requested from the map application 23.

[0074] In this embodiment, the map application 23 requests map data for a 3×3 grid centered on the grid to which the current position of the vehicle belongs. Therefore, the map update control unit 13 predicts the grids including the planned travel route of the vehicle and the grids within the range of the 3×3 grid centered on the grid as the grids for which map data is requested from the map application 23. For example, Figure 5 In the situation shown, Figure 8 The mesh in the range enclosed by the thick dotted line is predicted to be a mesh for which map data is requested from the map application 23. Hereinafter, a mesh for which map data is predicted to be requested from the map application 23 is referred to as a "request prediction mesh."

[0075] When the map update control unit 13 predicts a mesh for which map data will be requested from the map application 23 , it identifies a mesh for which map data stored in the map database 11 is not the latest among the meshes predicted to request map data (predicted request meshes) as a mesh requiring update. Figure 8 The grid M in the request prediction grid (the grid in the range surrounded by the thick dotted line) is shown in FIG. 46 、M 55 、M 56 、M 65 、M 94 、M D1 The map data is not up to date and these grid M 46 、M 55 、M 56 、M 65 、M 94 、M D1 Examples where a grid update is determined to be necessary.

[0076] The map update control unit 13 can quickly determine whether the map data of each mesh stored in the map database 11 is the latest by referring to the update necessity data stored in the update necessity data storage unit 15 .

[0077] Figure 9 An example of whether the data storage unit 15 needs to update the data of each grid is shown in FIG. In this embodiment, the data storage unit 15 needs to update the data of each grid. In other words, the data storage unit 15 needs to update the data of each grid. In this embodiment, the data storage unit 15 needs to update the data of each grid is a flag stored in the address corresponding to the ID of the grid, that is, 1 bit of data. For example, in FIG. Figure 8 That grid M 46 、M 55 、M 56 、M 65 、M 94 、M D1 If the map data is not up to date, Figure 9 Thus, "1" is stored in the addresses "46," "55," "56," "65," "94," and "D1" of the data storage unit 15 indicating whether or not update is necessary, and "0" is stored in the addresses corresponding to the IDs of the other meshes (meshes with the latest map data). Furthermore, "0" or an invalid value may be stored in the addresses corresponding to meshes for which no map data exists.

[0078] By using a single bit to represent the update necessity data for each grid, the storage capacity of update necessity data storage unit 15 can be reduced, reducing the required memory resources and shortening the reading and writing speeds of update necessity data. Furthermore, by utilizing the cache memory of an SoC (System on Chip) as update necessity data storage unit 15, processing speed can be further increased.

[0079] If the map update control unit 13 determines that a grid requires updating, it then determines whether the map data for that grid can be updated before a request is made from the map application 23. This determination can be made based on factors such as the distance from the vehicle to the grid requiring updating, the vehicle's driving speed, and the download speed of the update map data. Hereinafter, the ability to update the grid's map data before a request is made from the map application 23 will be referred to as "map data that can be updated in time" and the inability to update the grid's map data before a request is made from the map application 23, respectively.

[0080] If the map data for the mesh requiring update is determined to be updateable (map data update is available in time) before the map application 23 requests the map data for the mesh requiring update, the map update control unit 13 performs a first map update process. This first map update process uses the update map data downloaded from the map distribution server 30 by the update map data acquisition unit 14 to quickly update the map data for the mesh requiring update. On the other hand, if the map data for the mesh requiring update is determined to be updateable (map data update is available in time) before the map application 23 requests the map data for the mesh requiring update, the map update control unit 13 performs a second map update process. This second map update process updates the map data for the mesh requiring update when the operation of the map application 23 satisfies a predetermined condition. This predetermined condition is hereinafter referred to as the "second map update process execution condition."

[0081] As the second map updating process execution condition, for example, the following conditions can be considered:

[0082] (a) The action of the map application 23 is completed;

[0083] (b) The next action of the map application 23 is started;

[0084] (c) All map data currently being used by the map application 23 is the latest map data;

[0085] (d) The map application 23 releases map data and the like.

[0086] Alternatively, satisfaction of any one of these multiple conditions may be used as the second map updating process execution condition.

[0087] For example, in Figure 8 That way the grid M 46 If it is determined that the grid needs to be updated, if it is determined that there is time to update the grid M 46 The map data of the map update control unit 13 is updated quickly. 46 The first map update process of the map data is performed. As a result, the mesh M 46 The map data becomes the latest, such as Figure 10 As shown, the grid M 46 It is no longer necessary to update the grid (the grid M stored in the whether to update the data storage unit 15) 46 Whether the data needs to be updated is rewritten to "0").

[0088] In addition, when multiple grids need to be updated, the map update control unit 13 may provide map data to the map application 23 based on the grid farthest from the current position of the vehicle in the direction of travel (for example, Figure 8 The middle is the grid M 37 ) as the starting point, the first map update process is performed on the map data of the grids that need to be updated in order from the nearest to the farthest in the direction of travel. This can reduce the possibility of the grids that are not updated in time.

[0089] On the other hand, if it is judged that it is too late to update the grid M 46 In the case of map data of 46 The map data is updated, and the grid M is performed in the second map update process. 46 In this case, if Figure 11 That way, the grid M 46 Keeping the state that the grid needs to be updated, the grid M is requested from the map application 23. 46 Map data, providing grid M to map application 23 46 Old version of map data.

[0090] If the map update control unit 13 determines to update the map data of any mesh in the second map update process, the first map update process will not be restarted until the second map update process is actually performed. Figure 8 In the example, it can also be considered that although there is no time to update the grid M 46 Map data, but in time to update the grid M 56 This is because, in this case, if the grid M 46 The map data of the grid M is updated by the second map update process. 56When the first map update process is performed on the map data, the old map data and the latest map data are mixed and provided to the map application 23.

[0091] In addition, it is preferred that when multiple grids that need to be updated are determined, the map update control unit 13 determines whether it is possible to update the map data of all the grids that need to be updated in time. If it is determined that it is not possible to update the map data of a particular grid that needs to be updated, the second map update process is performed on the map data of all the grids that need to be updated. Figure 8 In the example, it can also be considered that although there is time to update the grid M 46 Map data, but too late to update the grid M 56 This is because, in this case, if the grid M 46 The map data of the grid M is updated by the first map update process. 56 When the second map update process is performed on the map data, the old map data and the latest map data are mixed and provided to the map application 23.

[0092] When the map update control unit 13 determines to update the map data of any mesh in the second map update process, it then, before actually performing the second map update process, causes the update map data acquisition unit 14 to store the update map data for the mesh to be updated, downloaded from the map distribution server 30, in the update map data storage unit 16. This operation of the map update control unit 13 is hereinafter referred to as "preparatory operation for the second map update process."

[0093] Specifically, the second map update process is performed by overwriting the map data in the map database 11 with the updated map data stored in the updated map data storage unit 16 during the preparation process. Once the second map update process is completed, the updated map data in the updated map data storage unit 16 is no longer needed, and the updated map data storage unit 16 is cleared. In other words, the second map update process is performed by moving the updated map data from the updated map data storage unit 16 to the map database 11.

[0094] By performing the second map updating process using the update map data stored in the update map data storage unit 16 in this manner, it is possible to omit the process of downloading the update map data from the map distribution server 30 during the second map updating process, thereby shortening the time required for the second map updating process.

[0095] However, in the second map updating process, only when the update map data stored in the update map data storage unit 16 is insufficient, that is, when the update map data corresponding to all the meshes requiring updating is not stored in the update map data storage unit 16, the map update control unit 13 may obtain the insufficient update map data from the map distribution server 30.

[0096] Furthermore, the second map update process need not necessarily be performed on all grids requiring update; instead, the second map update process may be performed on a predetermined range of grids, including the grid to which the vehicle's current location belongs. This is because, even if grids requiring update remain in locations far from the vehicle, the map data for those grids requiring update can still be updated using the first map update process.

[0097] In this manner, if there is no time to update the map data for a grid requiring update, the map update control unit 13 of the map data management device 10 does not immediately update the map data for that grid. Instead, the map update is performed after the map application 23's operation satisfies the second map update processing execution condition. As a result, a mixture of old map data and the latest map data is prevented from being provided to the map application 23, preventing the map application 23 from malfunctioning.

[0098] Figure 12 This is a flowchart showing the operation of the map data management device 10 according to the first embodiment. Figure 12 The flowchart of FIG. 1 illustrates the operation of the map data management device 10. Figure 12 The flow is an example of a case where the second map update processing execution condition is set to "the next operation start of the map application 23" (the above (b)).

[0099] When the map data management device 10 begins operation, the map update control unit 13 first updates the map data for the meshes for which map data updates were retained during the previous operation, using the update map data stored in the update map data storage unit 16 during the preparatory operation for the second map update process during the previous operation (step S100). Specifically, step S100 is the second map update process for the meshes for which map data updates were retained during the previous operation. If no update map data was stored in the update map data storage unit 16 at the end of the previous operation, no operation is performed in step S100.

[0100] Next, the map access unit 12 checks whether map data has been requested from the map application 23 (step S101). If map data has been requested from the map application 23 ("Yes" in step S101), the map access unit 12 reads the requested map data from the map database 11, stores the read map data in the pre-read map data storage unit 24, and provides the map data to the map application 23 (step S102). If map data has not been requested from the map application 23 ("No" in step S101), step S102 is not performed.

[0101] Next, the map update control unit 13 predicts the mesh for which map data will be requested from the map application 23 (step S103). It then checks whether all the map data for the mesh predicted to be requested from the map application 23 (the requested predicted mesh) is up to date (step S104). If all the map data for the requested predicted mesh is up to date ("Yes" in step S104), the map data management device 10 will not terminate its operations ("No" in step S105), for example, due to the vehicle's engine being turned off, and the process returns to step S101.

[0102] On the other hand, if the requested prediction grid includes a grid whose map data is not the latest ("No" in step S104), the map update control unit 13 determines that the grid requires updating (step S106). The map update control unit 13 then determines whether the map data for the grid requiring updating can be updated (whether it is still possible to update the map data) before requesting the map data for the grid requiring updating from the map application 23 (step S107).

[0103] At this point, if it is determined that there is still time to update the map data ("YES" in step S107), the map update control unit 13 obtains update map data from the map distribution server 30 via the update map data acquisition unit 14, and uses the obtained update map data to update the map data of the meshes requiring update (step S108). In other words, step S108 is the first map update process for quickly updating the map data of the meshes requiring update using the update map data obtained from the map distribution server 30.

[0104] On the other hand, if it is determined that it is too late to update the map data ("No" in step S107), the map update control unit 13 obtains the updated map data from the map distribution server 30 via the updated map data acquisition unit 14 and stores the obtained updated map data in the updated map data storage unit 16 (step S109). Specifically, step S109 is a preparatory operation for the second map update process, storing the updated map data downloaded from the map distribution server 30 in the updated map data storage unit 16. Furthermore, if a "No" determination is made in step S107, the "No" determination in step S107 continues until the map data management device 10 completes its operations in order to prevent old map data and the latest map data from being mixed and provided to the map application 23.

[0105] Thereafter, the process proceeds to step S105 . If the operation of the map data management device 10 has not been completed (“No” in step S105 ), the process returns to step S101 .

[0106] [Modification]

[0107] The map update control unit 13 does not necessarily need to immediately restart the first map update process after executing the second map update process. For example, if there are multiple grids requiring updating around the vehicle and no target for restarting the first map update process is available, the first map update process may not be restarted, but preparations for the second map update process may continue. Furthermore, if the processing load on the map data management device 10 is high, CPU or memory resources are insufficient, or the communication speed with the map distribution server 30 is slow, the first map update process may not be restarted, but preparations for the second map update process may continue.

[0108] Furthermore, the map update control unit 13 does not necessarily need to immediately execute the second map update process when the second map update process execution conditions are met. For example, if the map application 23 is providing route guidance for the vehicle, the preparatory steps for the second map update process may be continued until the route guidance is completed, at which point the second map update process may be executed. Furthermore, if the map application 23 terminates its use of map data immediately after the second map update process execution conditions are met, the second map update process may be executed upon resuming its use of map data by the map application 23.

[0109] The map data management device 10 may also use a display device to notify the user whether the latest map data or old map data before the update is provided to the map application 23. In this way, when the map application 23 does not work properly, the user can determine whether the cause is the map data.

[0110] exist Figure 8 , shows an example in which the map update control unit 13 predicts a grid for which map data is requested from the map application 23 based on the planned travel route of the vehicle. Even if a planned travel route for the vehicle is not set, the map update control unit 13 can predict the vehicle's travel route and use a predetermined range of grids, including the grids to which the predicted route belongs, as the grids for which map data is requested from the map application 23. Methods for predicting the vehicle's travel route include, for example, a method based on the vehicle's travel history and a method for predicting that the vehicle will continue traveling on the road it is currently traveling.

[0111] The positioning unit 22 of the onboard device 20 can also perform lane-by-lane map matching using high-precision map data (HD map data) to correct the vehicle's current position. This improves the vehicle's positioning accuracy. If the vehicle's position before correction does not match the lane, map matching based on the road shape can be performed. The HD map data used in map matching can be obtained from the map database 11 of the map data management device 10 or from the map distribution server 30.

[0112] In addition, the above-mentioned map matching may also be performed inside the map data management device 10 . Figure 13 The map data management device 10 is shown as including a map matching unit 17 that performs lane-by-lane map matching. The map matching unit 17 performs map matching to correct the current position of the vehicle, calculated by the positioning unit 22 based on GNSS positioning signals and sensor information of the vehicle, and then inputs the corrected position to the map access unit 12.

[0113] The map data management device 10 may provide the map application 23 with information on whether HD map data for the road on which the vehicle is traveling exists. The map application 23 may also change its operation based on whether HD map data for the road on which the vehicle is traveling exists.

[0114] Implementation 1 is effective when the map data stored in the map database 11 is high-precision map data (HD map data) that takes a long time to update, but the map data can also be normal map data (hereinafter also referred to as "SD map data") that includes road shape information for each road.

[0115] Furthermore, when the map update control unit 13 is performing the preparation operation for the second map update process and there is insufficient free space in the update map data storage unit 16 to store the update map data for the newly determined grid requiring update in the update map data storage unit 16, the map update control unit 13 may determine the priority of the newly determined grid requiring update and the priority of the corresponding grid requiring update already stored in the update map data storage unit 16, and select the update map data stored in the update map data storage unit 16 so that the update map data for the grid requiring update with the higher priority is stored in the update map data storage unit 16. Specifically, if the update map data already stored in the update map data storage unit 16 includes update map data for a grid requiring update with a lower priority than the newly determined grid requiring update, the map update control unit 13 may delete the update map data for the grid requiring update with the lower priority (e.g., the grid with the lowest priority), increase the free space in the update map data storage unit 16, and then store the update map data for the newly determined grid requiring update in the update map data storage unit 16. Furthermore, if there is no update map data for a mesh requiring update having a lower priority than the newly determined mesh requiring update among the update map data already stored in the update map data storage unit 16, the map update control unit 13 may not download the update map data for the newly determined mesh requiring update, but may maintain the update map data already stored in the update map data storage unit 16.

[0116] Methods for determining the priority of meshes requiring update include, for example, assigning higher priority to meshes closer to the vehicle, assigning higher priority to meshes requiring update closer to a specific POI such as the user's home, and assigning higher priority to meshes requiring update based on the frequency of map data use by a map application. Here, the priority of meshes requiring update refers to the priority of the map data used to update the meshes requiring update. Thus, for example, "updated map data for meshes requiring update with lower priority" can be referred to as "updated map data with lower priority."

[0117] Figure 14 and Figure 15 This is a flowchart showing the operation of the map data management device 10 when the map update control unit 13 selects or rejects the update map data stored in the update map data storage unit 16 .

[0118] Figure 14 and Figure 15 The process shown is to Figure 15 Steps S150 to S155 shown in FIG are added to Figure 12The other steps are the same as Figure 12 The process is the same, so the description is omitted here.

[0119] exist Figure 14 as well as Figure 15 In the process, if it is determined in step S107 that it is too late to update the map data ("No" in step S107), the map update control unit 13 accesses the map distribution server 30 to confirm the size of the update map data for the newly determined grid requiring update, and to check whether there is sufficient free space in the update map data storage unit 16 to store the update map data for the newly determined grid requiring update (step S150). If there is sufficient free space to store the update map data for the newly determined grid requiring update ("Yes" in step S150), the process proceeds to step S109, where the map update control unit 13 obtains the update map data from the map distribution server 30 via the update map data acquisition unit 14, and stores the obtained update map data in the update map data storage unit 16.

[0120] If there is insufficient free space to store the update map data for the newly determined grid requiring update ("No" in step S150), the map update control unit 13 compares the priority of the newly determined grid requiring update with the priority of the corresponding update map data for the grids already stored in the update map data storage unit 16 (step S151). Based on the priority of each grid requiring update, the map update control unit 13 determines whether the update map data for the newly determined grid requiring update should be stored in the update map data storage unit 16 (step S152). Specifically, if there is update map data with a lower priority than the update map data for the newly determined grid requiring update among the update map data already stored in the update map data storage unit 16, the update map data for the newly determined grid requiring update is determined to be stored. If not, the update map data for the newly determined grid requiring update is determined not to be stored.

[0121] As a result, if the update map data for the newly determined mesh requiring update is determined to be stored ("YES" in step S153), the map update control unit 13 deletes the update map data with a relatively low priority from the update map data stored in the update map data storage unit 16, and increases the free space in the update map data storage unit 16 (step S154). The update map data to be deleted in this case has a lower priority than the update map data for the newly determined mesh requiring update, and may be, for example, the data with the lowest priority.

[0122] The map update control unit 13 then obtains the update map data for the newly determined grid requiring updating from the map distribution server 30 and stores it in the update map data storage unit 16 (step S155). Specifically, step S155 is a preparatory step for the second map update process, in which the update map data downloaded from the map distribution server 30 is stored in the update map data storage unit 16. After step S155, the process proceeds to step S105.

[0123] If it is determined that the update map data for the newly determined mesh requiring update is not to be saved ("No" in step S153), steps S154 and S155 are skipped and the process proceeds to step S105. Specifically, in this case, the update map data for the newly determined mesh requiring update is not downloaded, and the already saved update map data is maintained in the update map data storage unit 16.

[0124] <Implementation Method 2>

[0125] High-precision map data (HD map data) was initially deployed for highways and major roads, and has subsequently been expanded to general roads. Consequently, currently, HD map data is mostly available only in grids encompassing highways and major roads. In Embodiment 2, focusing on these characteristics of HD map data, a map data management device 10 is proposed that predicts the grid for which map data is requested from a map application 23.

[0126] Figure 16 This is a block diagram showing the configuration of a map data management device 10 according to the second embodiment. Figure 16 The structure of the map data management device 10 is relative to Figure 1 The configuration shown is a configuration in which the update map data storage unit 16 is replaced with a mesh connection management data storage unit 18. In the second embodiment, the map data stored in the map database 11 is also HD map data.

[0127] The mesh connection management data storage unit 18 is a storage medium that stores mesh connection management data, which indicates whether HD map data exists in each mesh. In this embodiment, the map update control unit 13 pre-accesses the map distribution server 30 (e.g., upon startup of the map data management device 10) to confirm which meshes contain HD map data and stores the result as mesh connection management data in the mesh connection management data storage unit 18. Pre-storing the mesh connection management data in the mesh connection management data storage unit 18 reduces the number of times the map update control unit 13 accesses the map distribution server 30 to confirm the presence of HD map data for each mesh, thereby accelerating processing speed.

[0128] Furthermore, although the number of accesses to the map distribution server 30 increases, the map update control unit 13 can also access the map distribution server 30 each time it needs to confirm the presence of HD map data for each mesh. In this case, the mesh connection management data storage unit 18 is unnecessary.

[0129] For example, in Figure 17 In the map of , when HD map data exists only in the meshes (meshes surrounded by thick dotted lines) containing highways, the mesh connection management data storage unit 18 stores, for example, Figure 18 That grid connects the management data. Figure 18 The mesh connection management data in the MAP is a flag, or 1-bit data, stored at the address corresponding to each mesh ID. A "1" is stored at the address corresponding to the mesh ID for which HD map data exists, while a "0" is stored at the address corresponding to the mesh ID for which HD map data does not exist.

[0130] By expressing the mesh connection management data corresponding to each mesh using a single bit, the storage capacity of mesh connection management data storage unit 18 can be reduced, reducing the required memory resources and shortening the speed of reading and writing mesh connection management data. Furthermore, by utilizing the cache memory of an SoC (System on Chip) as mesh connection management data storage unit 18, processing speed can be further increased.

[0131] In the second embodiment, the operation of the map update control unit 13 is different from that in the first embodiment. The map update control unit 13 of the second embodiment predicts a grid for which HD map data exists, connected to the grid to which the current position of the vehicle belongs, as a grid for which map data is requested from the map application 23. For example, Figure 19 Then, if the position of the vehicle is grid M 28 , then from the grid M 28 The meshes in the range of the meshes where the connected HD map data exists (the range surrounded by the thick dotted line) are predicted to be the meshes for which the map data is requested from the map application 23. Figure 19 In the above example, the vehicle's traveling direction is added, and only the grids that exist ahead of the vehicle's traveling direction are predicted as grids for the requested map data.

[0132] The map update control unit 13 can quickly perform processing for confirming connections of meshes in the HD map data by referring to the mesh connection management data stored in the mesh connection management data storage unit 18 .

[0133] When the map update control unit 13 predicts a mesh for which map data will be requested from the map application 23 , it identifies a mesh for which map data stored in the map database 11 is not the latest among the meshes predicted to request map data (predicted request meshes) as a mesh requiring update. Figure 19 In the request prediction grid (the grid surrounded by the thick dotted line), the grid M 46 、M 55 、M 56 、M 65 、M 94 、M 98 、M D1 Examples where a grid update is determined to be necessary.

[0134] As in the first embodiment, the map update control unit 13 can quickly determine whether the map data of each mesh stored in the map database 11 is the latest by referring to the update necessity data stored in the update necessity data storage unit 15 .

[0135] When the map update control unit 13 determines that a mesh needs to be updated, the update map data acquisition unit 14 acquires update map data for the mesh that needs to be updated from the map distribution server 30 , and updates the map data for the mesh that needs to be updated.

[0136] Thus, in the second embodiment, the map update control unit 13 predicts the meshes for which map data is requested from the map application 23 using a simple method based on connections to meshes with HD map data. Furthermore, meshes for which no HD map data exists are excluded from the prediction targets. This allows the map update control unit 13 to quickly predict the meshes for which map data is requested from the map application 23 and identify the meshes requiring an update, reducing the likelihood of encountering a situation where map data is not updated in time. As a result, it prevents the map application 23 from being provided with a mixture of old and latest map data, preventing the map application 23 from malfunctioning.

[0137] In addition, when multiple grids need to be updated, the map update control unit 13 may provide map data to the map application 23 based on the grid farthest from the current position of the vehicle in the direction of travel (for example, Figure 19 The middle is the grid M 37 ) as the starting point, and update the map data of the grids that need to be updated in order from near to far from the starting grid in the direction of travel. This can further reduce the possibility of grids that are not updated in time.

[0138] Figure 20 This is a flowchart showing the operation of the map data management device 10 according to the second embodiment. Figure 20 The process is to Figure 12The process is obtained by replacing steps S100 and S109 of the process with steps S110 and S111 respectively. Figure 12 The process is the same as that of FIG. 1 , and therefore the description here is omitted (the operation of the map update control unit 13 in step S103 of predicting the mesh of the map data requested from the map application 23 is as described above).

[0139] Step S110 is performed when the map data management device 10 begins operation. In step S110, the map update control unit 13 updates the map data for the grid surrounding the current position of the vehicle. This process is a pre-processing to prevent map data from being updated too late immediately after the map data management device 10 begins operation, and can be similar to the map data update process performed in a typical map database.

[0140] Step S111 is performed when it is too late to update the map data, that is, when the determination in step S107 is "No." Step S111 terminates the process of providing map data to the map application 23 to prevent outdated map data from being provided to the map application 23. In the second embodiment, the prediction of the meshes for which map data is requested from the map application 23 and the determination of the meshes requiring update are performed at high speed. This reduces the likelihood of not being able to update the map data in time, and therefore the likelihood of executing step S111 is also reduced.

[0141] [Modification]

[0142] exist Figure 19 , but in the case where the planned driving route of the vehicle is set, the map update control unit 13 may also be configured as follows. Figure 21 As shown, a grid for which HD map data exists and which is predetermined based on the planned travel route is used as a grid for which map data is predicted to be requested from the map application 23 (requested predicted grid).

[0143] Furthermore, in the second embodiment, cells for which HD map data exists and are connected to the cell to which the current location belongs are used as the requested prediction cells. However, the requested prediction cells may also be determined by further considering road connectivity. Specifically, the map update control unit 13 may use cells for which HD map data exists and are connected to roads within the cell to which the current vehicle belongs as the requested prediction cells. This eliminates only cells for which roads do not connect to roads within the cell to which the current vehicle belongs, further accelerating processing speed.

[0144] In the case of considering the connection of roads, the mesh connection management data storage unit 18 may store mesh connection management data indicating the connection relationship of the roads in each mesh. For example, the mesh connection management data of each mesh may be a 4-bit data indicating which of the four meshes (north, south, west, and east) the road in the mesh is connected to. For example, the mesh (e.g., the mesh to which the road in the mesh is connected) Figure 17 Grid M 84 ) can be set to "1100", and the grids connected to the road and the left and right grids (e.g. Figure 17 Grid M 93 ) can be set to "0011", and the grid connection management data of the road and all the grids above, below, left and right (for example Figure 17 Grid M 94 )'s grid connection management data can be set to "1111".

[0145] In addition, when there is a bifurcation point on the road connected to the road within the grid to which the current position belongs, and the direction of travel of the vehicle at the bifurcation point is not determined, when predicting the grid for which map data is requested from the map application 23, the map update control unit 13 searches from the bifurcation point toward each bifurcation direction for a grid with high-precision map data connected from the grid to which the current position belongs, or for a grid with high-precision map data connected from the road within the grid to which the current position belongs.

[0146] At this time, if Figure 22 As shown, by keeping the search grid within a certain distance from the bifurcation point ( Figure 22 By searching within a grid (within the circle shown), the increase in processing load can be suppressed. The search grid range does not need to be circular. For example, the direction with a high probability of travel can be determined from the vehicle's driving history. For this direction with a high probability of travel, grids further away can be searched than for other directions. The direction of a specific POI, such as the driver's home, can be set as the direction with a high probability of travel for the vehicle.

[0147] Then, if the vehicle passes the fork point and determines the direction of travel at the fork point, the map update control unit 13 searches for a grid with high-precision map data connected from the grid to which the current position belongs, or a grid with high-precision map data connected from a road within the grid to which the current position belongs, from the fork point toward the direction of travel, thereby predicting a grid for which map data is requested from the map application 23. For example, according to Figure 22 In the state of the vehicle, when the vehicle goes straight north at the fork point, the map update control unit 13 Figure 23 Then, the grid predicted to request map data from the map application 23 is searched northward from the branch point. As a result, the grid MD1 It is determined that the grid needs to be updated. In addition, if the vehicle turns right to the east at the branch point, Figure 24 As shown, the map update control unit 13 searches eastward from the branch point for a mesh for which map data is predicted to be requested from the map application 23. As a result, the mesh M 98 It is determined that the mesh needs to be updated. Thus, by omitting searches in directions different from the traveling direction, an increase in processing load can be suppressed.

[0148] <Implementation Method 3>

[0149] In Embodiment 3, an example of combining Embodiment 1 and Embodiment 2 is shown. Figure 25 This is a block diagram showing the configuration of a map data management device 10 according to the third embodiment. Figure 25 The structure of the map data management device 10 is relative to Figure 1 The illustrated configuration is obtained by adding a mesh connection management data storage unit 18. In the third embodiment, the map data stored in the map database 11 is also HD map data.

[0150] In the third embodiment, the map update control unit 13 predicts the grid for which map data is requested from the map application 23 using the method of the second embodiment (a method based on the connection of grids where HD map data exists), and updates the map data of the grid requiring update using the method of the first embodiment (a method for performing the first map update process and the second map update process).

[0151] The operation of the map data management device 10 of the third embodiment can be performed in the same manner as that of the first embodiment. Figure 12 However, in this embodiment, the method of the second embodiment is used to perform step S103 of predicting the mesh of the map data requested from the map application 23 .

[0152] According to embodiment 3, both the effect of embodiment 2, which can reduce the probability of not being able to update map data in time, and the effect of embodiment 1, which can prevent old map data and the latest map data from being mixed and provided to the map application 23 by performing the second map update process when there is no time to update the map data, can be obtained.

[0153] <Implementation Method 4>

[0154] The map data management device 10 of Embodiments 1 to 3 manages either HD map data or SD map data. Embodiment 4 shows an example of a map data management device 10 that manages both HD map data and SD map data.

[0155] Figure 26The configuration of the map data management device 10 according to the fourth embodiment is shown. The configuration of the map data management device 10 according to the fourth embodiment is different from that shown as a modified example of the first embodiment. Figure 13 The map data management device 10 is similar to the SD map data management device 10 , but each component of the map data management device 10 is configured to support both SD map data and HD map data.

[0156] For example, the map database 11 stores HD map data and SD map data in grid units. The update map data storage unit 16 stores update map data for updating the HD map data and update map data for updating the SD map data. The map access unit 12 can read both HD map data and SD map data from the map database 11, provide the HD map data to the map application 23, and provide both the HD map data and SD map data to the map matching unit 17.

[0157] Each element of the map data management device 10 manages the HD map data and the SD map data as separate files. The range of each mesh in the HD map data is assumed to be the same as the range of each mesh in the SD map data.

[0158] The operation of the map data management device 10 in the fourth embodiment is basically the same as that of the modified example of the first embodiment. However, the map data management device 10 in the fourth embodiment uses both HD map data and SD map data to transmit information to the map application 23 regarding whether the vehicle is traveling on a road for which HD map data exists. Hereinafter, roads for which HD map data exists are referred to as "HD roads," and roads for which only SD map data exists are referred to as "SD roads."

[0159] Figure 27 This is a flowchart showing the operation of the map application 23 in the fourth embodiment. Figure 27 The process is relative to Figure 2 The process of FIG. 20 adds step S210 before step S203 . In step S210 , the map application 23 obtains information from the map data management device 10 as to whether the vehicle is traveling on an HD road.

[0160] Furthermore, in this embodiment, the operation of the map application 23 in step S203 varies depending on whether the vehicle is traveling on an HD road. For example, when the vehicle is traveling on an HD road, the map application 23 executes ADAS functions using HD map data. Otherwise, the map application executes ADAS functions using only information from the vehicle's surrounding sensors.

[0161] For example, if the map application 23 detects white lines on the road and executes lane keeping control, if the vehicle is traveling on an HD road, even if white lines are difficult to detect due to obstacles or curves, lane keeping can continue based on the lane shape known from the HD map data. However, if the vehicle is not traveling on an HD road, lane keeping accuracy decreases, so a safer control approach, such as reducing the driving speed, may be employed.

[0162] Figure 28 This is a flowchart showing the operation of the map data management device 10 according to the fourth embodiment. Figure 28 The process is relative to Figure 12 The process adds step S120 and replaces step S102 with step S121.

[0163] In step S120, the map matching unit 17 performs map matching to determine the vehicle's location using the SD map data and the HD map data. When the vehicle is traveling on an SD road (i.e., a road for which HD map data does not exist), the SD map data can be used for map matching to detect the road the vehicle is traveling on. Map matching is a well-known method, and a detailed description thereof will be omitted. For example, Japanese Patent Application Laid-Open No. 2018-96743 discloses a method for determining the road on which the vehicle is traveling.

[0164] In step S121, the map access unit 12 provides the map data requested from the map application 23 to the map application 23, and the map matching unit 17 provides the map matching result, that is, the information about the road on which the host vehicle is traveling, to the map application 23. The information about the road on which the host vehicle is traveling includes information about whether the host vehicle is traveling on an HD road.

[0165] Furthermore, the second map update process in step S100, the confirmation of the need for map data update in step S104, the first map update process in step S108, and the preparatory actions for the second map update process in step S109 are performed for both the HD map data and the SD map data. Furthermore, step S103 of predicting the mesh for which map data is requested from the map application 23 can be performed using the method of embodiment 1 (based on the planned travel route of the vehicle, etc.) or the method of embodiment 2 (based on the connection of meshes for which HD map data exists).

[0166] According to the fourth embodiment, the operation of the map application 23 can be changed depending on whether the vehicle is traveling on an HD road. Furthermore, because the map database 11 stores not only HD map data but also SD map data, map matching can be performed even when the vehicle is traveling on a road for which HD map data does not exist. Furthermore, it is possible to prevent map data from being delayed in updating for both HD and SD map data.

[0167] [Modification]

[0168] The grids of the HD map data and the SD map data may be different from each other. For example, the area of ​​one grid of the HD map data may be the same as the area of ​​3×3 grids of the SD map data.

[0169] The range of grids used to confirm whether a map data update is necessary, that is, the range of grids used to predict whether a map data request is required from the map application 23, may differ between HD map data and SD map data. For example, the range of grids used to confirm whether an HD map data update is necessary may be larger than the range of grids used to confirm whether an SD map data update is necessary. This allows HD map data updates to be performed for grids with a larger range than for SD map data updates. Furthermore, when the vehicle is traveling on an HD road, the range of grids used to confirm whether an HD map data update is necessary may be larger than the range of grids used to confirm whether an SD map data update is necessary.

[0170] The map update control unit 13 may prioritize updating the HD map data over updating the SD map data. For example, if downloading both HD and SD map data does not allow for sufficient time to update the HD map data, the first map update process may be performed only on the HD map data without updating the SD map data, or preparatory steps may be performed on the SD map data for the second map update process.

[0171] Furthermore, if downloading both HD map data and SD map data does not guarantee sufficient time for performing the preparatory operation for the second map update process for the HD map data, it is possible to perform the preparatory operation for the second map update process only for the HD map data and omit the preparatory operation for the second map update process for the SD map data. In this case, the second map update process for the SD map data is performed by obtaining the update map data from the map distribution server 30.

[0172] In the fourth embodiment, the operation flow of the map data management device 10 is shown by performing the operation of the map data management device 10 in accordance with the first embodiment. Figure 12 The process is obtained by adding step S120 and replacing step S102 with step S121. Figure 28However, the operation flow of the map data management device 10 according to the fourth embodiment may be the same as that shown in the second embodiment. Figure 20 The process is obtained by adding step S120 and replacing step S102 with step S121.

[0173] In this case, during the map data update process in step S110, the HD map data may be updated with priority over the SD map data. Specifically, while at least the HD map data update is completed in step S110, part or all of the SD map data update process may be performed in parallel with the provision of the HD map data to the map application 23 (processing from step S101 onwards).

[0174] In the fourth embodiment, SD map data is used for map matching and for processing within the map data management device 10, such as estimating the road on which the vehicle is traveling. However, similarly to HD map data, SD map data can also be provided to the map application 23 and used for navigation functions executed by the map application 23.

[0175] <Hardware Configuration Example of Map Data Management Device>

[0176] Figure 29 and Figure 30 1 and 2 are diagrams each showing an example of the hardware configuration of the map data management device 10 . Figure 1 、 Figure 13 、 Figure 16 、 Figure 25 as well as Figure 26 The functions of the components of the map data management device 10 are performed by, for example, Figure 29 The map data management device 10 is implemented using the processing circuit 50 shown. Specifically, the map data management device 10 includes the processing circuit 50. This processing circuit 50 is configured to provide map data stored in the map database to the map application in response to a request from the map application, obtain update map data, which is the latest map data for each grid, from the map distribution server, and update the map data stored in the map database using the update map data. The processing circuit 50 may be dedicated hardware or may be configured using a processor (also referred to as a central processing unit (CPU)) that executes a program stored in memory, a processing device, an arithmetic unit, a microprocessor, a microcomputer, or a DSP (digital signal processor).

[0177] When the processing circuit 50 is dedicated hardware, the processing circuit 50 may be, for example, a single circuit, a composite circuit, a programmable processor, a parallel programmable processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. The functions of the components of the map data management device 10 may be implemented using separate processing circuits, or these functions may be integrated and implemented using a single processing circuit.

[0178] Figure 30 The figure shows an example of the hardware structure of the map data management device 10, in which the processing circuit 50 is configured using a processor 51 that executes a program. In this case, the functions of the components of the map data management device 10 are implemented by software (software, firmware, or a combination of software and firmware). The software is expressed in the form of a program and stored in the memory 52. ​​The processor 51 reads and executes the program stored in the memory 52, thereby implementing the functions of each component. Specifically, the map data management device 10 includes the memory 52 for storing the program. When executed by the processor 51, the program ultimately performs the following tasks: providing map data stored in the map database to the map application in response to a request from the map application; obtaining update map data, which is the latest map data for each grid, from the map distribution server; and updating the map data stored in the map database using the update map data. In other words, the program can also be said to cause a computer to execute the steps and methods for the components of the map data management device 10.

[0179] Here, the memory 52 can be, for example, non-volatile or volatile semiconductor memories such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), as well as HDD (Hard Disk Drive), magnetic disk, floppy disk, optical disk, compact disk, mini disk, DVD (Digital Versatile Disc) and its drive device, or all storage media used in the future.

[0180] The above description describes a configuration in which the functions of the components of the map data management device 10 are implemented by either hardware or software. However, the present invention is not limited to this configuration. Alternatively, a configuration may be employed in which some components of the map data management device 10 are implemented by dedicated hardware, while others are implemented by software. For example, the functions of some components may be implemented by the dedicated hardware processing circuit 50, while the functions of others may be implemented by the processor 51, which reads and executes programs stored in the memory 52.

[0181] As described above, the map data management device 10 can realize the above-mentioned functions through hardware, software, etc., or a combination thereof.

[0182] In addition, the various embodiments can be freely combined, or the various embodiments can be appropriately modified or omitted.

[0183] It will be understood that the above description is in all respects illustrative and that numerous variations not shown are conceivable.

[0184] Label Description

[0185] 10 map data management device, 11 map database, 12 map access unit, 13 map update control unit, 14 update map data acquisition unit, 15 update data need or not unit, 16 update map data storage unit, 17 map matching unit, 18 grid connection management data storage unit, 20 vehicle-mounted device, 21 communication device, 22 positioning unit, 23 map application, 24 pre-read map data storage unit, 30 map distribution server, 50 processing circuit, 51 processor, 52 memory.

Claims

1. A map data management device, characterized in that: include: a map database storing map data of each grid obtained by dividing a map into grids; a map access unit configured to provide the map data stored in the map database to the map application in response to a request from the map application; an update map data acquisition unit that acquires update map data, which is the latest map data for each mesh, from a map distribution server; as well as a map update control unit that updates the map data stored in the map database using the update map data, The map update control unit predicts a grid for requesting map data from the map application. Among the grids predicted to request map data, a grid whose map data stored in the map database is not the latest is determined as a grid requiring update, If the map data of the mesh requiring updating can be updated before the map data of the mesh requiring updating is requested from the map application, a first map updating process is performed to quickly update the map data of the mesh requiring updating. If the map data of the mesh requiring updating cannot be updated before the map data of the mesh requiring updating is requested from the map application, a second map updating process is performed to update the map data of the mesh requiring updating when the operation of the map application satisfies a predetermined condition. When a plurality of the grids requiring updating are determined, if it is determined that it is too late to update the map data of one of the grids requiring updating, the map update control unit performs the second map update process on the map data of all the grids requiring updating. The predetermined condition is any one or more of the following conditions: The action of the map application has ended; The next action of the map application has begun; The map data being provided to the map application are all the latest map data; as well as The map application releases the map data.

2. The map data management device according to claim 1, wherein The map data stored in the map database is high-precision map data including road shape information for each lane.

3. The map data management device according to claim 1, wherein The second map updating process is performed on meshes within a predetermined range including the mesh to which the current position belongs.

4. The map data management device according to claim 1, wherein The system further includes an update map data storage unit configured to store the update map data of the mesh requiring update before the second map update process is performed, if the map data of the mesh requiring update cannot be updated before the map data of the mesh requiring update is requested from the map application.

5. The map data management device according to claim 4, wherein: In the second map updating process, when the update map data stored in the update map data storage unit alone is insufficient, the map update control unit acquires the insufficient update map data from the map distribution server.

6. The map data management device according to claim 4, wherein: If the map data of the grid requiring updating cannot be updated before the map data of the grid requiring updating is requested from the map application, and if there is insufficient free capacity in the update map data storage unit to store the update map data of the grid requiring updating, the map update control unit selects the update map data stored in the update map data storage unit.

7. The map data management device according to claim 1, wherein: In the first map update process, the map update control unit updates the map data of the grids that need to be updated in order from the grid at the starting point toward the direction of travel, starting from the grid farthest from the current position among the grids providing map data to the map application.

8. The map data management device according to claim 1, wherein: The map data stored in the map database includes both high-precision map data and normal map data, wherein the high-precision map data includes road shape information for each lane and the normal map data includes road shape information for each road. The high-precision map data is provided to the map application, The general map data is used for map matching, which is used to determine the current position. The map update control unit performs the first map update process and the second map update process on both the high-precision map data and the normal map data.

9. The map data management device according to claim 8, wherein: The map update control unit prioritizes updating of the high-precision map data over updating of the normal map data.

10. The map data management device according to claim 8, wherein The map update control unit updates the high-precision map data for a wider range of meshes than for updating normal map data.

11. The map data management device according to claim 8, wherein In a case where the high-precision map data of the grid that needs to be updated can be updated but the normal map data of the grid that needs to be updated cannot be updated before the map data of the grid that needs to be updated is requested from the map application, the map update control unit performs a first map update process on the high-precision map data of the grid that needs to be updated and performs a second map update process on the normal map data of the grid that needs to be updated.

12. The map data management device according to claim 1, wherein The map data stored in the map database includes high-precision map data including road shape information for each lane. The map update control unit predicts a mesh containing the high-precision map data connected from a mesh to which the current position belongs, or a mesh containing the high-precision map data on a road connected from a road within the mesh to which the current position belongs, as a mesh for which map data is requested from the map application.

13. The map data management device according to claim 12, wherein: The invention also includes a mesh connection management data storage unit that stores data indicating whether the high-precision map data exists in each mesh.

14. The map data management device according to claim 13, wherein: In the mesh connection management data storage unit, data indicating whether the high-precision map data exists in each mesh is 1-bit data stored in an address corresponding to the ID of the mesh.

15. The map data management device according to claim 12, wherein: The invention further includes a mesh connection management data storage unit that stores data indicating which direction of mesh a road in each mesh is connected to.

16. The map data management device according to claim 12, wherein: The map update control unit updates the map data of the grids that need to be updated in order from near to far from the starting grid toward the direction of travel, starting from the grid at the starting point and proceeding in order from near to far in the direction of travel.

17. The map data management device according to claim 12, wherein: When there is a branch point on a road connected from a road within the grid to which the current position belongs, and the direction of travel at the branch point is uncertain, the map update control unit searches for a grid with the high-precision map data connected from the grid to which the current position belongs, or a grid with the high-precision map data connected from a road within the grid to which the current position belongs, in each branch direction, when predicting a grid for which map data is requested from the map application. When there is a bifurcation point on a road connected from a road within a grid to which the current position belongs, and the direction of travel at the bifurcation point is determined, the map update control unit searches from the bifurcation point toward the direction of travel for a grid with the high-precision map data connected from the grid to which the current position belongs, or a grid with the high-precision map data connected from a road within the grid to which the current position belongs, when predicting a grid for which map data is requested from the map application.

18. The map data management device according to claim 12, wherein: The map data stored in the map database also includes normal map data including road shape information of each road. The high-precision map data is provided to the map application, The general map data is used for map matching, which is used to determine the current position. The map update control unit updates both the high-precision map data and the normal map data.

19. The map data management device according to claim 18, wherein: The map update control unit prioritizes updating of the high-precision map data over updating of the normal map data.

20. The map data management device according to claim 18, wherein The map update control unit updates the high-precision map data for a wider range of meshes than for updating normal map data.

21. A map data management method for managing a map database storing map data of each grid obtained by dividing a map into grids, wherein: The map access unit of the map data management device provides the map data stored in the map database to the map application in response to a request from the map application. The update map data acquisition unit of the map data management device acquires the update map data as the latest map data of each mesh from the map distribution server. The map update control unit of the map data management device updates the map data stored in the map database using the update map data. In the process of updating the map data stored in the map database, the map update control unit predicting a grid requesting map data from the map application, Among the grids predicted to request map data, a grid whose map data stored in the map database is not the latest is determined as a grid requiring update, If the map data of the mesh requiring updating can be updated before the map data of the mesh requiring updating is requested from the map application, a first map updating process is performed to quickly update the map data of the mesh requiring updating. If the map data of the mesh requiring updating cannot be updated before the map data of the mesh requiring updating is requested from the map application, a second map updating process is performed to update the map data of the mesh requiring updating when the operation of the map application satisfies a predetermined condition. When a plurality of the grids requiring updating are determined, if it is determined that it is too late to update the map data of one of the grids requiring updating, the map update control unit performs the second map update process on the map data of all the grids requiring updating. The predetermined condition is any one or more of the following conditions: The action of the map application has ended; The next action of the map application has begun; The map data being provided to the map application is all up-to-date map data; and The map application releases the map data.

22. The map data management method according to claim 21, wherein: The map data stored in the map database includes high-precision map data including road shape information for each lane. In the process of updating the map data stored in the map database, the map update control unit A grid where the high-precision map data exists and is connected from a grid to which the current position belongs, or a grid where the high-precision map data exists and is connected from a road within the grid to which the current position belongs is predicted as a grid where map data is requested from the map application.

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