Map processing device and map processing method

Abstract

To achieve both of capacity reduction of a storage which holds map data in a device and performance maintenance of the device in a map processing device used for travel support of a vehicle.SOLUTION: A map processing device according to the present invention includes a map data look-ahead part which can acquire multiple types of map data including lane connection data showing connection information between lane sections in the extension direction of a lane and lane group connection data showing connection information between lane group sections in the extension direction of the lane group consisting of one or more lanes, and acquires the type of map data according to the conditions of a prescribed point when acquiring the map data of the prescribed point in front of the own vehicle.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a map processing device and a map processing method. [Background technology]

[0002] Conventionally, a technology for pre-reading map data has been disclosed in a map creation application used in an electronic map display system or the like (see, for example, Patent Document 1). Patent Document 1 discloses a technology for selecting map data tiles of an area including a first route and an area including a secondary route (such as a return route) selected based on the first route from the entire available map data, and extracting map data. In the map data pre-reading technology disclosed in Patent Document 1, map data of a secondary route is pre-read based on the first route, but the amount of accessed map data is adjusted based on the priority of the secondary route. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2015-501956 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, conventionally, a technology for pre-reading map data has been proposed for a map processing device, but in this technical field, there is a demand for reducing the capacity of the storage that holds the map data in the device to reduce costs. In order to solve this problem, it is necessary to reduce the capacity of the map data held in the map processing device, but if the capacity of the held map data is reduced too much, the performance of the map processing device may be degraded. Therefore, in the technical field of map processing devices, there is a demand for the development of a technology that can achieve both a reduction in the capacity of the storage that holds the map data in the device and the maintenance of the performance of the device.

[0005] In particular, map processing devices that enable driving assistance at the lane level of roads (hereinafter simply referred to as "lanes"), which is necessary for automatic driving of vehicles that has been developed in recent years, use map data with a higher degree of detail than conventional car navigation systems that can be used for driving assistance at the road level. Therefore, in map processing devices that handle such map data with a higher degree of detail, the capacity of map data stored in the device also becomes larger, and the above-mentioned demand is also great. For example, the above-mentioned Patent Document 1 discloses a technology for pre-reading another route (secondary route) assumed from the vehicle position and route, but on expressways, the secondary route tends to be long. Therefore, even if the technology disclosed in the above-mentioned Patent Document 1 is applied to a map processing device that handles map data with a higher degree of detail, it is difficult to pre-read all map data of the secondary route required for driving assistance.

[0006] The present invention has been made to meet the above demand, and an object of the present invention is to provide a technology for a map processing device used for vehicle driving support that can achieve both reduction in the capacity of the storage that holds map data within the device and maintenance of the device's performance. [Means for solving the problem]

[0007] In order to solve the above problems, the map processing device of the present invention includes a map data pre-reading unit capable of acquiring multiple types of map data. The multiple types of map data include lane connection data indicating connection information between lane sections in the extension direction of the lanes, and lane group connection data indicating connection information between lane group sections in the extension direction of a lane group composed of one or more lanes. When acquiring map data for a specific point ahead of the vehicle, the map data pre-reading unit acquires a type of map data according to the conditions of the specific point.

[0008] In addition, in order to solve the above problem, the map processing method of the present invention includes, when the map data pre-reading unit of the map processing device of the present invention acquires map data of a specified point ahead of the vehicle, acquiring a type of map data according to the conditions of the specified point. Effect of the Invention

[0009] According to the present invention having the above configuration, in a map processing device used for vehicle driving support, it is possible to achieve both a reduction in the capacity of the storage that holds map data within the device and maintenance of the device's performance. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of an in-vehicle system including a map processing device according to an embodiment of the present invention; [Diagram 2] 1 is a functional block configuration diagram of a map processing device according to an embodiment of the present invention. [Diagram 3] 2 is a diagram showing the relationship between various map data stored in a storage unit of a map processing device according to an embodiment of the present invention and various applications in which the various map data are used; FIG. [Figure 4] 1 is a diagram illustrating a hardware configuration of a map processing device according to an embodiment of the present invention. [Diagram 5] 2 is a schematic diagram showing the relationship between various map data pre-read in a map processing device according to an embodiment of the present invention and the distance from the vehicle position to a pre-read target point; FIG. [Figure 6] 5 is a flowchart showing a procedure of a pre-reading process of various map data by a map processing device according to an embodiment of the present invention. [Figure 7] 5 is a flowchart showing a procedure of a pre-reading process of various map data performed by a map processing device according to an embodiment of the present invention. [Figure 8] FIG. 2 is a diagram for explaining an overview of a first route change operation example when route deviation occurs, which is performed by a map processing device according to an embodiment of the present invention. [Figure 9] FIG. 11 is a diagram showing an operation flow of a first route change operation example when a route deviation occurs, by a map processing device according to an embodiment of the present invention. [Figure 10] FIG. 11 is a diagram for explaining an overview of a second route change operation example when route deviation occurs, which is performed by the map processing device according to one embodiment of the present invention. [Figure 11] FIG. 11 is a diagram showing an operational flow of a second route changing operation when route deviation occurs, performed by the map processing device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A map processing device and a map processing method (map data pre-reading method) according to an embodiment of the present invention will be specifically described below with reference to the drawings. Note that the present invention is applicable to a vehicle control computing device (e.g., MPU (Map Positioning Unit) or the like) with which an on-board ECU (Electronic Control Unit) for an Advanced Driver Assistance System (ADAS) or Autonomous Driving (AD) can communicate.

[0012] [In-vehicle system configuration] Fig. 1 is a schematic diagram of an in-vehicle system including a map processing device according to an embodiment of the present invention, in which only components related to various processes performed by the map processing device are shown.

[0013] 1, an in-vehicle system 1 of a vehicle equipped with an automatic driving function includes a map processing device 2, a car navigation system 3 (hereinafter referred to as "car navigation 3"), and an automatic driving control device 4, and each component is connected to each other within the in-vehicle system 1. In addition, the map processing device 2 is connected via a communication network 6 to a map distribution server 5 provided externally, for example, in a cloud.

[0014] The map distribution server 5 stores various map data with a high degree of detail at the lane level required for autonomous driving assistance of the vehicle (for example, lane connection data, lane attribute data, lane boundary data, etc., which will be described later; hereinafter, these data will be referred to as "high-precision map data"). During startup, the map processing device 2 acquires various high-precision map data of the surroundings of the vehicle on demand from the map distribution server 5. Although not shown in the figure, the car navigation system 3 is connected to a map distribution server for the car navigation system provided externally, such as a cloud, via a communication network, and acquires various map data of the road level of the surroundings of the vehicle on demand from the map distribution server for the car navigation system.

[0015] The map processing device 2 has a function of acquiring in advance (hereinafter referred to as "pre-reading") various high-precision map data of a recommended route (hereinafter referred to as "planned driving route") to a destination required for the autonomous driving assistance of the vehicle and its surrounding routes from the map distribution server 5. Note that the "surrounding route of the planned driving route" here means a route that can branch off from the planned driving route. The map processing device 2 searches for the planned driving route using the various high-precision map data that have been pre-read, and outputs information on the planned driving route determined by the search process to the autonomous driving control device 4. In addition, in this embodiment, as described later, when the vehicle deviates from the planned driving route, the map processing device 2 also searches for and determines a new planned driving route using the various high-precision map data that have been pre-read. Note that the internal configuration and processing contents of the map processing device 2 will be described later with reference to the drawings.

[0016] The car navigation system 3 searches for a recommended route to the destination using various road-level map data of the surroundings of the vehicle acquired from a map distribution server for car navigation systems, and sets the recommended route obtained by the search process as a planned driving route. In addition, the car navigation system 3 outputs various information such as the planned driving route, destination, and route search conditions set in the car navigation system 3 to the map processing device 2.

[0017] The automatic driving control device 4 uses information on a planned driving route to a destination set by the map processing device 2 or the car navigation system 3 to perform automatic driving control of the vehicle.

[0018] [Map processing device configuration] Fig. 2 is a configuration diagram of functional blocks of a map processing device 2 according to an embodiment of the present invention. Note that Fig. 2 shows only components related to the process of pre-reading various high-precision geographic data by the map processing device 2 and the process of searching for and determining a planned driving route to a destination.

[0019] 2, the map processing device 2 includes a control unit 10, a storage unit 11, a sensor unit 12, a first communication unit 13, a second communication unit 14, and a third communication unit 15. The control unit 10 is connected to the storage unit 11, the sensor unit 12, the first communication unit 13, and the second communication unit 14, and the storage unit 11 is connected to the third communication unit 15.

[0020] The control unit 10 searches for a recommended route at the lane level to the destination using various data (information) acquired from the storage unit 11, the sensor unit 12, and the first communication unit 13, and outputs information on the planned driving route obtained as a result of the search to the automatic driving control device 4 via the second communication unit 14. In addition, as described later, when the vehicle deviates from the planned driving route, the control unit 10 also performs a process of searching for and determining a new planned driving route. The internal configuration of the control unit 10 will be described later.

[0021] The storage unit 11 is connected to an external map distribution server 5 via a third communication unit. The storage unit 11 stores various high-precision map data that enables lane-level automatic driving assistance distributed from the map distribution server 5. In this embodiment, it is assumed that the map distribution server 5 stores various high-precision map data that enables lane-level automatic driving assistance not only for expressways but also for general roads.

[0022] The storage unit 11 also includes a lane connection / attribute data storage unit 31, a lane boundary data storage unit 32, a lane shape data storage unit 33, and a lane group connection data storage unit .

[0023] The lane connection and attribute data storage unit 31 stores information (hereinafter referred to as "lane connection data") regarding the connection relationship between lane sections that are connected to each other via branch points (e.g., intersections, etc., hereinafter referred to as "nodes") where the structure of the travel lane changes physically. Note that the lane connection data includes various information such as not only connection information between lane sections (between nodes) in the extension direction of the lane, but also information regarding the position coordinates of the node, lane identification information, travel direction, and information regarding whether the lane can be changed at the node.

[0024] Furthermore, the lane connection and attribute data storage unit 31 stores information on the attributes (properties and characteristics) of each lane between nodes (hereinafter referred to as "lane attribute data"). The lane attribute data includes various information between nodes, such as lane type information, lane width, lane curvature, lane gradient type, and information indicating whether the lane is passable. Note that the information indicating whether the lane is passable, which is included in the lane attribute data, includes real-time or time-limited traffic information, such as information on congestion and information on construction work.

[0025] Information about the boundaries between adjacent lanes in a direction perpendicular to the direction in which the lanes extend (hereinafter referred to as "lane boundary data") is stored in the lane boundary data storage unit 32. Note that the lane boundary data includes information such as the type of boundary line between the lanes (e.g., white line, orange line, etc.) and the pattern type of the boundary line.

[0026] The lane shape data storage unit 33 stores information relating to the shape of each lane between nodes (hereinafter referred to as "lane shape data"). In this embodiment, the lane shape data includes shape data of the center line of each lane (hereinafter referred to as "lane center line shape data") and shape data of the boundaries of each lane (hereinafter referred to as "lane boundary shape data"). Both the lane center line shape data and the lane boundary shape data are composed of coordinate point sequence data.

[0027] Furthermore, in the autonomous driving support by the map processing device 2, connection information is used that aggregates multiple lanes existing between nodes into one group (hereinafter referred to as a "lane group"). In this embodiment, a lane group is also set for a driving route when the number of lanes existing between nodes is one (for example, a general road in Figs. 8 to 10 described later). That is, in this embodiment, a lane group is composed of one or more lanes. Then, information on the connection between lane groups that are connected to each other via nodes (hereinafter referred to as "lane group connection data") is stored in the lane group connection data storage unit 34. It is sufficient that the lane group connection data includes a minimum amount of connection information between lane groups, and includes various information such as identification information of the lane group other than the connection information between lane groups (between nodes) in the extension direction of the lane group.

[0028] The sensor unit 12 has various devices for recognizing structures and vehicles around the vehicle, the position of the vehicle, the driving conditions of the vehicle, etc. Specifically, the sensor unit 12 includes various devices such as a camera (imaging device) capable of capturing images of the conditions around the vehicle, a GPS (Global Positioning System) module capable of measuring the position of the vehicle at road level, and an acceleration sensor and an angular velocity sensor capable of measuring the driving conditions of the vehicle. The various pieces of information acquired by the sensor unit 12 are input to the control unit 10, and the control unit 10 performs a recognition process of structures and vehicles around the vehicle and an estimation process of the vehicle's position based on this information.

[0029] The first communication unit 13 is connected to the car navigation system 3. Various information set in the car navigation system 3, such as a planned driving route, a destination, and route search conditions, is transmitted to the control unit 10 via the first communication unit 13. The second communication unit 14 is connected to the automatic driving control device 4. Information on a planned driving route to the destination determined by the control unit 10 is transmitted to the automatic driving control device 4 via the second communication unit 14. In addition, the third communication unit 15 is connected to an external map distribution server 5 via the communication network 6, receives various high-precision map data distributed from the map distribution server 5, and outputs the received various high-precision map data to the storage unit 11. Note that the operations of the first communication unit 13 to the third communication unit 15 are controlled by the control unit 10.

[0030] [Control Unit Configuration] As shown in FIG. 2, the control unit 10 functionally includes a surrounding recognition unit 20, a self-position estimation unit 21, a candidate route search unit 22 (route search unit), a route selection unit 23 (route determination unit), a lane data pre-reading unit 24 (map data pre-reading unit), and a map access unit 25.

[0031] The functional blocks are connected in terms of functional processing as follows: The surrounding recognition unit 20 is connected to the sensor unit 12, the self-position estimation unit 21, and the lane data read-ahead unit 24. The self-position estimation unit 21 is connected to the sensor unit 12, the candidate route search unit 22, and the lane data read-ahead unit 24. The candidate route search unit 22 is connected to the first communication unit 13, the route selection unit 23, and the lane data read-ahead unit 24. The route selection unit 23 is connected to the second communication unit 14 and the map access unit 25. The lane data read-ahead unit 24 is connected to the map access unit 25. In addition, the map access unit 25 is connected to the lane connection / attribute data storage unit 31, the lane boundary data storage unit 32, the lane shape data storage unit 33, and the lane group connection data storage unit 34 in the storage unit 11, respectively.

[0032] The surroundings recognition unit 20 recognizes the presence and position of structures and vehicles in the vicinity ahead of the vehicle, based on an image of the surroundings ahead of the vehicle input from a camera (not shown) in the sensor unit 12 and various high-precision map data input from the lane data read-ahead unit 24. Then, the surroundings recognition unit 20 outputs the recognition results of the structures and vehicles around the vehicle to the self-position estimation unit 21 and the lane data read-ahead unit 24.

[0033] The self-position estimation unit 21 estimates the vehicle position at the lane level based on the recognition results of structures and vehicles around the vehicle input from the surrounding recognition unit 20, various sensor information input from the sensor unit 12, and various high-precision map data input from the lane data read-ahead unit 24.

[0034] In this embodiment, two types of applications are installed as applications for estimating the vehicle position by the self-position estimation unit 21. Specifically, an application that estimates the vehicle position using a surrounding image in front of the vehicle and high-precision map data, and an application that estimates the vehicle position using high-precision map data are installed. Hereinafter, the former application is referred to as a "high-precision locator (camera recognition)" and the latter application is referred to as a "high-precision locator (map matching)".

[0035] In this embodiment, the type of high-precision map data used in the vehicle position estimation process by the self-position estimation unit 21 also changes depending on the vehicle position estimation application used. FIG. 3 is a diagram showing the relationship between the type of vehicle position estimation application and the type of high-precision map data used, and the high-precision map data used is indicated by a circle. Note that FIG. 3 also shows high-precision map data used in the candidate route search process by the candidate route search unit 22 (described later) and the planned driving route determination process by the route selection unit 23 (described later) (see the "lane level search" column in the figure). In the figure, the high-precision map data used in the candidate route search process by the candidate route search unit 22 (described later) is indicated by a circle, and the high-precision map data used in the planned driving route determination process by the route selection unit 23 (described later) is indicated by a triangle.

[0036] The high-precision map data used by the high-precision locator (camera recognition) is, as shown in Fig. 3, lane connection data, lane attribute data, lane boundary data, lane centerline shape data, lane boundary shape data, and lane group connection data. That is, the high-precision locator (camera recognition) uses all types of high-precision map data stored in the storage unit 11. On the other hand, the high-precision map data used by the high-precision locator (map matching) is lane connection data, lane attribute data, lane centerline shape data, and lane group connection data. That is, the high-precision map data used by the high-precision locator (map matching) does not include high-precision map data related to lane boundaries.

[0037] Then, the self-position estimation unit 21 outputs information on the vehicle position estimated by the high-precision locator (camera recognition) or the high-precision locator (map matching) to the candidate route search unit 22 and the lane data pre-read unit 24.

[0038] The candidate route searching unit 22 searches for candidates (hereinafter, referred to as "candidate routes") that can be recommended routes to the set destination. At this time, the candidate route searching unit 22 searches for a plurality of candidate routes based on the vehicle position input from the self-position estimating unit 21, various high-precision map data input from the lane data pre-reading unit 24, and information on the destination (position information, etc.) input from the car navigation system 3. As will be described later, when the vehicle deviates from the set planned driving route, the candidate route searching unit 22 performs a search process for a candidate route using only the lane group connection data as high-precision map data (see the circle in the "lane level search" column in FIG. 3). Then, the candidate route searching unit 22 outputs information on a plurality of candidate routes obtained by the search process to the route selecting unit 23.

[0039] Based on the lane connection data and lane attribute data input via the map access unit 25 (see the triangle mark in the "Lane Level Search" column in FIG. 3), the route selection unit 23 selects (determines) a planned driving route from among the multiple candidate routes input from the candidate route search unit 22. In addition, in the selection process of the planned driving route by the route selection unit 23, the multiple candidate routes are picked up in a predetermined order, and based on the lane attribute data of the picked candidate route, it is determined whether or not the candidate route is actually suitable for automatic driving. Then, if the picked candidate route is a route suitable for automatic driving (a drivable route), the route selection unit 23 determines the picked candidate route as the planned driving route. After that, the route selection unit 23 transmits information regarding the selected planned driving route ("Determined Route" in FIG. 3) to the automatic driving control device 4 via the second communication unit 14.

[0040] In addition, in the process of selecting a planned travel route by the route selection unit 23, one order is set in advance by the driver or the like from among the following pick-up orders (selection orders) of a plurality of types of candidate routes. (1) In order of least amount of high-precision map data loaded (2) Shortest route distance (3) Shortest travel time to the destination (4) The order of the search conditions for the initial planned route set in the car navigation system 3, etc.

[0041] In the above-mentioned pick-up order (1), since the capacity of the map data to be loaded is not known in advance, the candidate route is picked up in the order of the number of lane groups (nodes) to be newly loaded. In the above-mentioned pick-up order (2), the lane group connection data needs to include information on the distance between the lane groups (distance between nodes). In the above-mentioned pick-up order (3), the lane group connection data needs to include information on the average speed and to link the lane group connection data with traffic information. In the above-mentioned pick-up order (4), the pick-up order of the candidate routes is set according to the search conditions in the car navigation system 3, such as the use of expressways and arrival time, acquired via the first communication unit 13, etc. However, in the selection process of the planned travel route by the route selection unit 23, a candidate route for which the distance to the next node (branch) of the lane group or lane is short and the loading of high-precision map data is not in time is excluded.

[0042] The lane data read-ahead unit 24 reads (acquires) from the map distribution server 5 a plurality of types of high-precision map data of the planned driving route ahead of the vehicle and its surrounding routes, which are necessary for smooth automatic driving assistance of the vehicle. Specifically, the lane data read-ahead unit 24 selects a tile (hereinafter referred to as a "map tile") including the area of ​​the planned driving route ahead of the vehicle and / or its surrounding routes from a map divided into tiles, and reads in advance various types of high-precision map data of the roads included in the map tile. At this time, the type of high-precision map data to be read in advance changes according to the conditions of the read-ahead target point (predetermined point) ahead of the vehicle. Specifically, the type of high-precision map data to be read in advance changes according to conditions such as the distance on the driving route from the vehicle position to the read-ahead target point, whether the read-ahead target point is a point on the planned driving route, and the possibility of deviation from the planned driving route (ease of becoming a secondary route). The specific contents of the read-ahead process by the lane data read-ahead unit 24 will be described in detail later with reference to the drawings.

[0043] The map access unit 25 accesses the storage unit 11 to acquire various high-precision map data stored in the storage unit 11, and outputs the acquired various high-precision map data to the lane data pre-reading unit 24 and the route selection unit 23. Note that high-precision map data of a type corresponding to the above-mentioned conditions of the pre-read target points is output from the map access unit 25 to the lane data pre-reading unit 24, and lane connection data and lane attribute data of a candidate route are output from the map access unit 25 to the route selection unit 23. Note that, as described above, in this embodiment, the route selection unit 23 determines a planned driving route based on the lane attribute data, and therefore the high-precision map data input from the map access unit 25 to the route selection unit 23 may be only the lane attribute data of the candidate route.

[0044] [Hardware configuration of map processing device] The map processing device 2 of this embodiment can be configured with a processing device such as a computer device having a calculation function and a communication function. Fig. 4 is a block diagram showing an example of the hardware configuration of a processing device 100 applicable as the map processing device 2.

[0045] The arithmetic processing device 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, and a RAM (Random Access Memory) 103, all connected to a bus line 108. The arithmetic processing device 100 also includes a network I / F (Interface) 104, an operation unit 105, a display unit 106, and a non-volatile storage 107, all connected to the bus line 108. Although not shown in FIG. 4, the arithmetic processing device 100 also includes various interfaces used when executing input / output processing of various data (various information) between the arithmetic processing device 100 and external devices. Furthermore, although not shown in FIG. 4, the arithmetic processing device 100 also includes a component equivalent to the sensor unit 12 in FIG. 2.

[0046] The CPU 101 reads out program code of software for realizing various processing functions of the map processing device 2 from the ROM 102 to the RAM 103 and executes the program code. At this time, variables and parameters generated during the calculation process are also temporarily written to the RAM 103. That is, the control unit 10 of the map processing device 2 in FIG. 2 is included in the CPU 101.

[0047] The network I / F 104 is configured by, for example, a network interface card (NIC) or the like, and transmits and receives various data to and from each device connected thereto.

[0048] The operation unit 105 is composed of, for example, keys and buttons, and generates an operation signal according to the operation content input by the operator and supplies the operation signal to the CPU 101. For example, the pick-up order of the candidate routes in the process of selecting a planned travel route by the route selection unit 23 described above can be set by operating the operation unit 105. Such an operation may be performed via an operation unit (not shown) included in the car navigation system 3, in which case the map processing device 2 does not include the operation unit 105.

[0049] The display unit 106 is configured, for example, by a liquid crystal panel, and displays characters, images, and the like on a screen. The display unit 106 may also be configured by a touch panel, in which case the display unit 106 and the operation unit 105 are configured integrally. Note that the output information from the map processing device 2 may be displayed on a display unit (not shown) provided for displaying various information output from, for example, the car navigation system 3, in which case the map processing device 2 does not include the display unit 106.

[0050] The non-volatile storage 107 can be configured with, for example, a hard disk drive (HDD), a solid state drive (SSD), a flexible disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a non-volatile memory, and the like. The non-volatile storage 107 stores an operating system (OS), various parameters, and a program for making the arithmetic processing device 100 function as the map processing device 2. In this embodiment, the various high-precision map data described above is stored in the non-volatile storage 107, and the storage unit 11 of the map processing device 2 in FIG. 2 is included in the non-volatile storage 107. Note that information (data) such as a program, a table, and a file that realizes each function of the map processing device 2 may be stored in a recording medium such as an IC card, an SD card, or a DVD, in addition to the ROM 102 or the non-volatile storage 107.

[0051] [Outline of high-precision map data look-ahead function] In this embodiment, a high-precision map data read-ahead function by the lane data read-ahead unit 24 is provided, as shown in the following (A) to (C). (A) When the read-ahead target point is a point on the planned driving route, the lane data read-ahead unit 24 changes the type of high-precision map data to be read ahead (acquired) depending on the distance on the driving route from the vehicle position to the read-ahead target point. (B) When the read-ahead target point is a point on a peripheral route that can branch off from the planned travel route, the lane data read-ahead unit 24 reads in advance only the lane group connection data. (C) For points on a route that deviates from the planned driving route and is within a predetermined distance from the deviation point, the lane data read-ahead unit 24 reads in advance not only lane group connection data but also various high-precision map data necessary for autonomous driving assistance, such as lane connection data. At this time, the high-precision map data to be read in advance may be, for example, all types of high-precision map data shown in Fig. 3, or may be high-precision map data other than the high-precision map data related to lane boundaries.

[0052] In addition, in the map processing device 2 of the present embodiment, a configuration example having all of the above-mentioned (A) to (C) look-ahead functions will be described, but the present invention is not limited thereto. For example, the above-mentioned (C) look-ahead function (hereinafter referred to as the "deviation prediction function") may not be provided depending on, for example, the processing performance, memory capacity, etc. of the map processing device 2. Also, for example, a configuration having one of the above-mentioned (A) and (B) look-ahead functions may be provided. When only the above-mentioned (A) look-ahead function is provided, the type of high-precision map data read ahead at the look-ahead target point on the surrounding route also changes depending on the distance on the travel route from the vehicle position to the look-ahead target point. On the other hand, when only the above-mentioned (B) look-ahead function is provided, at the look-ahead target point on the planned travel route, not only lane group connection data but also various high-precision map data necessary for automatic driving support such as lane connection data are read ahead regardless of the distance from the vehicle position.

[0053] Here, the contents of the look-ahead function of (A) above will be specifically described. Fig. 5 is a schematic diagram showing the relationship between the type of high-precision map data read ahead by the lane data look-ahead unit 24 and the distance on the travel route from the vehicle position to the look-ahead target point in the look-ahead function of (A) above (when the look-ahead target point is a point on the planned travel route). Note that Fig. 5 illustrates an example of a road with two lanes on each side. Therefore, in the example shown in Fig. 5, four lanes are aggregated to form one lane group.

[0054] In the example shown in FIG. 5, one lane group area 40, i.e., one lane group section, is represented by a substantially rectangular block. The lane group connection data 41 is represented by nodes (branching points) marked with white circles, and is provided at the entry and exit points of each lane group area 40. The lane connection data 42 is represented by nodes (branching points) marked with black circles, and is provided at the entry and exit points of the corresponding lanes in each lane group area 40. The lane attribute and shape data 43 (lane attribute data and lane center line shape data) are represented by solid lines (links) connecting the nodes of the lane connection data 42. The map data 44 relating to the lane boundaries (lane boundary data and lane boundary shape data) are represented by a pattern (white line pattern) in which white rectangles are arranged at a predetermined interval along the extension direction of the road. The map data 44 relating to the lane boundaries includes, for example, lines indicating boundaries with side walls and data on the side walls themselves, in addition to the white line pattern shown in the figure.

[0055] If the read-ahead target point is a point 51 located close to the vehicle position (e.g., several kilometers ahead), as shown in Fig. 5, the lane data read-ahead unit 24 acquires various high-precision map data used in the estimation process of the vehicle position by a high-precision locator (camera recognition). Specifically, in read-ahead for the close-up point 51, the lane data read-ahead unit 24 reads (acquires) lane group connection data 41, lane connection data 42, lane attribute and shape data 43, and map data 44 related to lane boundaries. That is, in read-ahead for the close-up point 51, the lane data read-ahead unit 24 acquires all types of high-precision map data shown in Fig. 3. In addition, in read-ahead for the close-up point 51, the lane data read-ahead unit 24 also acquires an image of the surroundings ahead of the vehicle captured by the camera in the sensor unit 12, thereby acquiring information on physical structures 45 and vehicles present in the surroundings ahead of the vehicle.

[0056] 5 shows an example in which the lane data pre-reading unit 24 pre-reads (acquires) not only high-precision map data for two lanes in the driving direction of the vehicle, but also high-precision map data for two lanes in the opposite driving direction, in pre-reading for a nearby point 51, but the present invention is not limited to this. In pre-reading for a nearby point 51, for example, when there is a physical structure 45 in the vicinity in front of the vehicle, the lane data pre-reading unit 24 may pre-read high-precision map data only in a range visible from the vehicle (for example, a range shown in a peripheral image). For example, when a median strip is provided as the physical structure 45 between the two lanes in the driving direction of the vehicle and the opposite lane, and the opposite lane is not visible from the vehicle, the lane data pre-reading unit 24 may pre-read only high-precision map data for two lanes in the driving direction of the vehicle. In this case, there is no need to read high-precision map data for the opposite lane, so the amount of high-precision map data to be acquired can be further reduced.

[0057] If the look-ahead target point is a point 52 that is at a medium distance from the vehicle position, the lane data look-ahead unit 24 acquires various high-precision map data used in the estimation process of the vehicle position by the high-precision locator (map matching). Specifically, in look-ahead for the medium-distance point 52, the lane data look-ahead unit 24 looks ahead (acquires) the lane group connection data 41, the lane connection data 42, and the lane attribute and shape data 43. Note that in look-ahead for the medium-distance point 52, the lane data look-ahead unit 24 acquires only high-precision map data for two lanes in the driving direction of the vehicle.

[0058] Furthermore, if the read-ahead target point is point 53, which is far away from the vehicle position, the lane data read-ahead unit 24 reads (acquires) only the lane group connection data 41. If the read-ahead target point is point 54, which is farther away than point 53, the lane data read-ahead unit 24 does not read (acquire) high-precision map data. Note that the above-mentioned boundary values ​​of "short distance", "medium distance", and "long distance", as well as the boundary values ​​of distances at which high-precision map data is not read ahead (first predetermined distance D1 to third predetermined distance D3 in FIG. 7 described later) can be set appropriately depending on, for example, the type of driving route (general road, expressway, etc.), the processing performance of the map processing device 2, memory capacity, etc.

[0059] [Pre-reading of high-precision map data using map processing device] Next, a description will be given of a process flow of pre-reading high-precision map data executed by the lane data pre-reading unit 24 of the map processing device 2. Note that the pre-reading process by the lane data pre-reading unit 24 described below is controlled by the CPU 101 in FIG.

[0060] In addition, the look-ahead processing by the lane data look-ahead unit 24 described below will be described for the case where the look-ahead target point is on the planned driving route and the case where the target point is on a peripheral route of the planned driving route, that is, the look-ahead functions (A) and (B) described above. In addition, the deviation prediction function (C) described above, which takes into account the possibility of deviation from the planned driving route, will be outlined appropriately in the description of the processing flow below.

[0061] <Overall processing flow for pre-reading high-precision map data> First, a process flow of the entire high-precision map data pre-reading process executed by the lane data pre-reading unit 24 will be described with reference to Fig. 6. Fig. 6 is a flowchart showing the procedure of the entire high-precision map data pre-reading process executed by the lane data pre-reading unit 24. The entire high-precision map data pre-reading process shown in Fig. 6 is started when the map processing device 2 is started (powered on).

[0062] First, the lane data read-ahead unit 24 judges whether there is free time to perform the read-ahead process (S1). In this process, the lane data read-ahead unit 24 judges whether the CPU 101 has time to perform the map data read-ahead process, that is, whether the CPU 101 has a margin for the processing load, based on the current processing load of the CPU 101. For example, when the vehicle deviates from the planned driving route and a search process for a new route to the destination (for example, the operation described in FIG. 8 to FIG. 11 described later) is being performed, the processing load of the CPU 101 for the route search process becomes high, and there is no margin for the read-ahead process. Therefore, in such a situation, there is no free time to perform the read-ahead process, the judgment process of S1 is NO, and the process (read-ahead process) from S3 described later on is not performed.

[0063] If the lane data pre-reading unit 24 determines in S1 that there is no free time for performing the pre-reading process (if S1 is determined to be NO), the lane data pre-reading unit 24 performs a standby process for a certain period of time (S2). After the process of S2, the lane data pre-reading unit 24 returns the process to the process of S1 and repeats the processes from S1 onward.

[0064] On the other hand, if the lane data read-ahead unit 24 determines in S1 that there is free time for performing read-ahead processing (YES determination in S1), the lane data read-ahead unit 24 determines whether or not to perform read-ahead processing on the planned driving route (S3). In this process, if there are still points on the planned driving route to the destination for which read-ahead processing has not been performed at the time of this process, the lane data read-ahead unit 24 determines to perform read-ahead processing on the planned driving route (YES determination). On the other hand, if there are still points on the planned driving route to the destination for which read-ahead processing has not been performed at the time of this process, the lane data read-ahead unit 24 determines not to perform read-ahead processing on the planned driving route (NO determination).

[0065] In S3, when the lane data read-ahead unit 24 determines to perform read-ahead processing on the planned driving route (when S3 is determined to be YES), the lane data read-ahead unit 24 acquires map tiles including points on the planned driving route for which high-precision map data has not yet been acquired (S4). That is, in this processing, the lane data read-ahead unit 24 acquires map tiles including read-ahead target points on the planned driving route for which read-ahead processing has not yet been performed.

[0066] Next, the lane data read-ahead unit 24 performs a process of reading ahead high-precision map data (S5). In this process, the lane data read-ahead unit 24 reads ahead (acquires) high-precision map data of each read-ahead target point on the planned driving route included in the map tile acquired in the process of S4 from the map distribution server 5. At this time, as described in Fig. 5, the type of high-precision map data read ahead by the lane data read-ahead unit 24 differs depending on the distance on the driving route from the vehicle position to the read-ahead target point. Details of the map data read-ahead execution process in S5 will be described later with reference to Fig. 7 described below.

[0067] On the other hand, if the lane data read-ahead unit 24 determines in S3 not to perform read-ahead processing on the planned driving route (if S3 is determined to be NO), the lane data read-ahead unit 24 acquires map tiles including points on the peripheral routes of the planned driving route for which high-precision map data has not been acquired (S6). That is, in this processing, the lane data read-ahead unit 24 acquires map tiles including read-ahead target points for which read-ahead processing has not been performed on the peripheral routes of the planned driving route. At this time, the lane data read-ahead unit 24 acquires the map tile closest to the vehicle position.

[0068] Next, the lane data pre-reading unit 24 performs a process of pre-reading lane group connection data (S7). In this process, the lane data pre-reading unit 24 pre-reads (acquires) lane group connection data of each pre-read target point on the surrounding route included in the map tile acquired in the process of S6 from the map distribution server 5. Note that, in the case where a deviation prediction function is provided, in the process of S7, not only the lane group connection data but also various high-precision map data necessary for autonomous driving assistance such as lane connection data is pre-read (acquired) for points on the surrounding route within a predetermined distance from the deviation point.

[0069] After the process of S5 or S7, the lane data pre-reading unit 24 judges whether or not to continue the pre-reading process of high-precision map data (S8). In this process, the lane data pre-reading unit 24 judges whether or not the power supply of the map processing device 2 has been turned off, and if the power supply of the map processing device 2 has not been turned off, the pre-reading process of high-precision map data is continued, so the judgment process of S8 is a YES judgment. On the other hand, if the power supply of the map processing device 2 has been turned off, the judgment process of S7 is a NO judgment.

[0070] If the lane data pre-reading unit 24 determines in S8 to continue the pre-reading process of the high-precision map data (if S8 is judged as YES), the lane data pre-reading unit 24 returns the process to S1 and repeats the processes from S1 onwards. On the other hand, if the lane data pre-reading unit 24 determines in S8 not to continue the pre-reading process of the high-precision map data (if S8 is judged as NO: if the power is turned off), the lane data pre-reading unit 24 ends the pre-reading process of the high-precision map data.

[0071] <Processing flow of high-precision map data pre-reading execution process (processing of S5 above)> Next, a process flow of the read-ahead execution process performed in S5 in the overall process flow of the high precision map data read-ahead process shown in Fig. 6 will be described with reference to Fig. 7. Fig. 7 is a flowchart showing the procedure of the high precision map data read-ahead execution process performed in S5.

[0072] First, the lane data pre-reading unit 24 judges whether or not the distance d from the vehicle position to a predetermined pre-read target point on the planned driving route included in the acquired map tile is less than a first predetermined distance D1 (S11). Note that here, the "distance d from the vehicle position to the predetermined pre-read target point" is the distance on the planned driving route from the vehicle position to the predetermined pre-read target point. Also, the "first predetermined distance D1" here is a threshold value for judging whether or not the distance d from the vehicle position to the predetermined pre-read target point is a short distance.

[0073] In S11, if the lane data read-ahead unit 24 determines that the distance d from the vehicle position to the predetermined read-ahead target point is less than the first predetermined distance D1 (YES in S11), the lane data read-ahead unit 24 performs the process of S14 described below. On the other hand, if the lane data read-ahead unit 24 determines that the distance d from the vehicle position to the predetermined read-ahead target point is not less than the first predetermined distance D1 (NO in S11), the lane data read-ahead unit 24 determines whether the distance d from the vehicle position to the predetermined read-ahead target point is less than a second predetermined distance D2 (S12). The "second predetermined distance D2" here is a threshold value for determining whether the distance d from the vehicle position to the predetermined read-ahead target point is a medium distance.

[0074] If the lane data pre-reading unit 24 determines in S12 that the distance d from the vehicle position to the predetermined pre-read target point is less than the second predetermined distance D2 (YES in S12), the lane data pre-reading unit 24 performs the process of S15 described below. On the other hand, if the lane data pre-reading unit 24 determines in S12 that the distance d from the vehicle position to the predetermined pre-read target point is not less than the second predetermined distance D2 (NO in S12), the lane data pre-reading unit 24 determines whether the distance d from the vehicle position to the predetermined pre-read target point is less than a third predetermined distance D3 (S13). Note that the "third predetermined distance D3" here is a threshold value for determining whether the distance d from the vehicle position to the predetermined pre-read target point is a long distance.

[0075] In S13, if the lane data read-ahead unit 24 determines that the distance d from the vehicle position to the predetermined read-ahead target point is less than the third predetermined distance D3 (YES in S13), the lane data read-ahead unit 24 performs the process of S16, which will be described later. On the other hand, in S13, if the lane data read-ahead unit 24 determines that the distance d from the vehicle position to the predetermined read-ahead target point is not less than the third predetermined distance D3 (NO in S13), the lane data read-ahead unit 24 performs the process of S17, which will be described later.

[0076] Returning to the explanation of the process of S11, if the result of S11 is YES, i.e., if the distance d from the vehicle position to the predetermined read-ahead target point is short, the lane data read-ahead unit 24 performs a process of read-ahead of lane boundary and boundary shape data (S14). Specifically, the lane data read-ahead unit 24 reads (acquires) the lane boundary data and lane boundary shape data of the predetermined read-ahead target point.

[0077] After the process of S14, or if the result of S12 is YES (if the distance d from the vehicle position to the predetermined read-ahead target point is a medium distance), the lane data read-ahead unit 24 performs a process of read-ahead of lane connection, attribute, and center line shape data (S15). Specifically, the lane data read-ahead unit 24 reads (acquires) the lane connection data, lane attribute data, and lane center line shape data of the predetermined read-ahead target point.

[0078] After processing of S15, or if S13 is judged as YES (if the distance d from the vehicle position to the specified look-ahead target point is long), the lane data look-ahead unit 24 performs a look-ahead process of the lane group connection data of the specified look-ahead target point (S16).

[0079] After the process of S16, or if the determination in S13 is NO, the lane data read-ahead unit 24 determines whether or not all of the read-ahead target points included in the acquired map tile have been selected (S17).

[0080] In S17, when it is determined that the lane data pre-reading unit 24 has not selected all the pre-reading target points (when S17 is a NO determination), the lane data pre-reading unit 24 returns the process to the process of S11 and repeats the processes after S11. At this time, the lane data pre-reading unit 24 newly selects a pre-reading target point where the pre-reading process has not been performed as a predetermined pre-reading target point and repeats the processes after S11.

[0081] On the other hand, in S17, when it is determined that the lane data pre-reading unit 24 has selected all the pre-reading target points (when S17 is a YES determination), the lane data pre-reading unit 24 ends the pre-reading execution process and moves the process to S8 during the pre-reading process (see FIG. 6).

[0082] As described above, in the pre-reading execution process on the planned travel route by the lane data pre-reading unit 24, if the distance d from the own vehicle position of the pre-reading target point is a short distance (d < D1: a distance within a predetermined range), the pre-reading processes of S14 to S16 are performed, and all types of high-precision map data are pre-read. In the pre-reading execution process on the planned travel route, if the distance d from the own vehicle position of the pre-reading target point is a medium distance (D1 ≤ d < D2), the pre-reading processes of S15 and S16 are performed, and high-precision map data other than the data related to the lane boundary is pre-read. Further, in the pre-reading execution process on the planned travel route, if the distance d from the own vehicle position of the pre-reading target point is a long distance (D2 ≤ d < D3: a distance within a specific range), the pre-reading process of S16 is performed, and only the lane group connection data is pre-read. In the pre-reading execution process of the present embodiment described above, even on the planned travel route, if the distance d from the own vehicle position of the pre-reading target point is equal to or greater than the third predetermined distance D3, the pre-reading processes of S14 to S16 are not performed, and high-precision map data is not pre-read (acquired).

[0083] [Route change operation when route deviation occurs by the map processing device] Next, a description will be given of an operation of changing the route (planned driving route) to the destination when the vehicle deviates from the planned driving route in the map processing device 2 of this embodiment. The route changing operation when the vehicle deviates from the route is performed by the candidate route searching unit 22 and the route selecting unit 23 in the map processing device 2, and the processing operation is controlled by the CPU 101 in FIG.

[0084] <First route change operation example> 8 is a diagram showing a situation in which route deviation occurs when the vehicle enters an expressway from an ordinary road, and an overview of a first route change operation performed by the map processing device 2 when the situation occurs. In the first route change operation example, consider the case in which the following route deviation situation occurs.

[0085] First, it is assumed that the planned driving route of the vehicle during automatic driving (hereinafter referred to as "original route Ro"), which is set in advance by the car navigation system 3, is a route (solid line arrow in the figure) from the entry point INa to the expressway from the general road to the merging point A with the expressway. Also, it is assumed that before the vehicle during automatic driving reaches the entry point INa, the driver sees a display on the general road that displays the congestion status of the expressway, or hears the guidance voice of the car navigation system 3, and understands that the section from the merging point A to the next merging point B on the expressway is congested. Then, it is assumed that the driver judges that the original route Ro, which turns right at the entry point INa, is not good, and suddenly takes the steering wheel (switches to manual driving), and goes straight without turning right at the entry point INa. When such a route deviation occurs, after the route deviation, the map processing device 2 searches for a new planned driving route (hereinafter referred to as "new route Rn") to the destination using the lane group connection data that has been read in advance. In the example shown in FIG. 8, after deviation from the route, a return route to the expressway from the entry point INb toward the junction B with the expressway (indicated by the dashed arrow in the figure) is determined as the new route Rn.

[0086] Here, the first route change operation performed by the map processing device 2 when the route deviation situation shown in Fig. 8 occurs, i.e., the route return operation to the expressway, will be described in more detail with reference to Fig. 9. Fig. 9 is a diagram showing the flow (situation) of the route change operation performed by the map processing device 2 when the route deviation situation shown in Fig. 8 occurs, and the relationship between the pre-read high precision map data and the acquired high precision map data in each situation of the route change operation.

[0087] In FIG. 9, similarly to FIG. 5, one lane group area is represented by a substantially rectangular block, lane group connection data is represented by a node (branch point) marked with a white circle, and lane connection data is represented by a node marked with a black circle. In FIG. 9, lane attribute data and lane center line shape data are represented by links (solid lines) connecting nodes marked with black circles. In FIG. 9, map data related to lane boundaries (lane boundary data and lane boundary shape data) are omitted for the sake of simplicity. In FIG. 9, in lane group areas where lane connection data (nodes marked with black circles) has been acquired (pre-read), the acquired lane group connection data (nodes marked with white circles) is omitted for the sake of simplicity. In FIG. 9, each lane group area is assumed to exist within a medium distance (see FIG. 5) from the vehicle.

[0088] 9 is a situation before the host vehicle deviates from the route. Therefore, in this situation, at least lane group connection data, lane connection data, lane attribute data, and lane center line shape data are pre-read (acquired) in each lane group area existing along the original route Ro previously set by the car navigation system 3. Note that in lane group areas existing close to the host vehicle, lane boundary data and lane boundary shape data, as well as an image of the surroundings ahead of the host vehicle captured by the camera in the sensor unit 12, are also acquired.

[0089] Moreover, in the situation (a1), mainly only lane group connection data is read ahead (acquired) in the lane group areas on the peripheral route of the original route Ro (see the nodes marked with white circles in the figure). However, at the entry point INa onto the expressway, the vehicle branches off onto a route different from the original route Ro. Therefore, in the situation (a1), in consideration of the possibility of the vehicle departing from the other route, lane connection data, lane attribute data, lane center line shape data, etc. are further read ahead in several lane group areas existing along the other route from the lane group area including the entry point INa (see "Departure Prediction" in FIG. 9).

[0090] After the situation (a1), in consideration of the congestion on the expressway, the vehicle continues straight (deviation) without turning right at the entry point INa, which is the situation (b1) in FIG. 9. In this case, the map processing device 2 (candidate route searching unit 22) of the vehicle performs a search process for a new route Rn to the destination using the lane group connection data that has been read ahead in each lane group area ahead of the route after the deviation. Then, in the situation (b1), this search process obtains multiple routes, including a return route (candidate route Rc) from the entry point INb to the expressway toward the junction point B, as candidate routes for the new route Rn.

[0091] After the situation (b1), the map processing device 2 (route selection unit 23) of the vehicle selects candidate routes in the order of least amount of high-precision map data loaded (in the order of least number of newly loaded nodes), and judges whether or not the candidate routes are suitable for autonomous driving of the vehicle. That is, the route selection unit 23 selects candidate routes in the order of earliest possible return to the expressway, and judges whether or not the candidate routes are suitable for autonomous driving. Therefore, in the example shown in FIG. 9, the map processing device 2 (route selection unit 23) first acquires lane connection data and lane attribute data of each lane group area existing along the candidate route Rc. This situation is the situation (c1) in FIG. 9. Therefore, in the situation (c1), the display mode of the acquired data in each lane group area between the entry point INb and the merging point B is represented by black circle nodes and links between the nodes.

[0092] In situation (c1), the map processing device 2 (route selection unit 23) refers to the lane attribute data of each lane group area along the candidate route Rc to determine whether the candidate route Rc is actually suitable for autonomous driving of the vehicle (whether it is possible to drive on the candidate route Rc). In the example shown in FIG. 9, the candidate route Rc is determined to be suitable for autonomous driving, and the map processing device 2 (route selection unit 23) determines the candidate route Rc as a new route Rn. After that, the map processing device 2 acquires other high-precision map data on the new route Rn, starting from the pre-read target point closest to the vehicle.

[0093] When a route deviation shown in Fig. 8 and Fig. 9 occurs, the map processing device 2 performs a route change operation as described above. In the above-mentioned first route change operation example, high-precision map data of each lane group area that becomes used or unused as the vehicle travels is appropriately deleted (discarded). In addition, in the above-mentioned first route change operation example, the original route Ro before the deviation is set by the car navigation system 3, but the present invention is not limited to this. For example, even if the original route Ro before the deviation is set by the map processing device 2 (control unit 10), a new route Rn is determined in the same manner as in the above-mentioned first route change operation example.

[0094] <Second route change operation example> FIG. 10 is a diagram showing a situation in which route deviation occurs when the vehicle enters an expressway from an ordinary road, and an overview of a second route change operation performed by the map processing device 2 when the situation occurs.

[0095] The route deviation occurrence situation shown in Fig. 10 is similar to that explained in Fig. 8, so the explanation will be omitted here. The example shown in Fig. 10 shows an example in which, after route deviation, a return route to the expressway from entry point INc toward junction point C with the expressway is determined as a new route Rn. Note that, in the example shown in Fig. 10, a return route to the expressway from entry point INb, which is between entry points INa and INc, toward junction point B with the expressway is also a candidate route Rc1, but this candidate route Rc1 is an example in which travel is not allowed.

[0096] Here, with reference to Fig. 11, the second route change operation performed by the map processing device 2 when the route deviation situation shown in Fig. 10 occurs, i.e., the route return operation to the expressway, will be described in more detail. Fig. 11 is a diagram showing the flow (situation) of the route change operation performed by the map processing device 2 when the route deviation situation shown in Fig. 10 occurs, and the relationship between the pre-read high precision map data and the acquired high precision map data in each situation of the route change operation. Note that the display mode of the lane group area and various high precision map data shown in Fig. 11 is the same as the display mode thereof explained in Fig. 9, and each lane group area shown in Fig. 11 is assumed to exist within a medium distance from the vehicle (see Fig. 5).

[0097] 11 shows a situation before the host vehicle deviates from the route. Therefore, in this situation, at least lane group connection data, lane connection data, lane attribute data, and lane center line shape data are pre-read (acquired) in each lane group area existing along the original route Ro previously set by the car navigation system 3. Note that in lane group areas existing close to the host vehicle, lane boundary data and lane boundary shape data, as well as an image of the surroundings ahead of the host vehicle captured by the camera in the sensor unit 12, are also acquired.

[0098] Also, in situation (a2), in lane group areas on the peripheral route of the original route Ro, mainly only lane group connection data is read ahead (acquired) (see the nodes marked with white circles in the figure). However, at the entry point INa onto the expressway, the route branches off onto a route different from the original route Ro. Therefore, in situation (a2), in consideration of the possibility of the vehicle departing from the other route, lane connection data, lane attribute data, lane centerline shape data, etc. are further read ahead in several lane group areas existing along the other route from the lane group area including the entry point INa (see "Departure Prediction" in FIG. 11).

[0099] After the situation (a2), in consideration of the congestion on the expressway, the vehicle continues straight (deviation) without turning right at the entry point INa, which is the situation (b2) in FIG. 11. In this case, the map processing device 2 (candidate route searching unit 22) of the vehicle performs a search process for a new route Rn to the destination using the lane group connection data that has been read ahead in each lane group area ahead of the route after the deviation. Then, in the situation (b2), this search process obtains multiple routes as candidate routes for the new route Rn, including a return route (candidate route Rc1) from the entry point INb to the expressway toward the junction B, and a return route (candidate route Rc2) from the entry point INc to the expressway toward the junction C.

[0100] After the situation (b2), the map processing device 2 (route selection unit 23) of the vehicle selects candidate routes in ascending order of the amount of high-precision map data loaded (in descending order of the number of newly loaded nodes), and judges whether or not the candidate routes are suitable for autonomous driving of the vehicle. That is, the route selection unit 23 selects candidate routes in descending order of the earliest possible return to the expressway, and judges whether or not the candidate routes are suitable for autonomous driving. Therefore, in the example shown in FIG. 11, the map processing device 2 (route selection unit 23) first acquires lane connection data and lane attribute data of each lane group area along the candidate route Rc1. This situation is the situation (c2) in FIG. 11.

[0101] In the situation (c2), the map processing device 2 (route selection unit 23) refers to the lane attribute data of each lane group area along the candidate route Rc1 to determine whether the candidate route Rc1 is actually suitable for autonomous driving (whether it is drivable). In the example shown in FIG. 11, consider a case where the candidate route Rc1 is not suitable for autonomous driving of the vehicle due to, for example, construction, congestion, lane curvature exceeding a threshold value, etc., midway through the driving section from the entry point INb to the merging point B. In this case, in the situation (c2), the map processing device 2 (route selection unit 23) determines that the candidate route Rc1 is not drivable and cannot be determined as the new route Rn (see the white cross in the figure).

[0102] After the situation (c2), the map processing device 2 (route selection unit 23) of the vehicle acquires lane connection data and lane attribute data of each lane group area along the candidate route Rc2. This situation is the situation (d2) in FIG. 11. Then, in the situation (d2), the map processing device 2 (route selection unit 23) refers to the lane attribute data of each lane group area along the candidate route Rc2 to determine whether or not the candidate route Rc2 is actually suitable for autonomous driving of the vehicle. In the example shown in FIG. 11, a case is considered in which the candidate route Rc2 is actually suitable for autonomous driving. In this case, in the situation (d2), the map processing device 2 (route selection unit 23) determines the candidate route Rc2 as the new route Rn. After that, the map processing device 2 acquires other high-precision map data on the new route Rn, starting from the pre-read target points close to the vehicle.

[0103] When a route deviation shown in Fig. 10 and Fig. 11 occurs, the map processing device 2 performs a route change operation as described above. Note that, in the above-mentioned second route change operation example, high-precision map data of each lane group area that becomes used or unused as the vehicle travels is also deleted (discarded) as appropriate. Also, in the above-mentioned second route change operation example, the original route Ro before the deviation was set by the car navigation system 3, but the present invention is not limited to this. For example, even if the original route Ro before the deviation was set by the map processing device 2 (control unit 10), a new route Rn is determined in the same manner as in the above-mentioned second route change operation example.

[0104] [Various effects] As described above, in the map processing device 2 of the present embodiment, when high-precision map data is pre-read (acquired) from the map distribution server 5, the type of high-precision map data to be pre-read (acquired) is changed on the planned driving route according to the distance from the vehicle position to the pre-read target point. For example, as described above, if the distance on the driving route from the vehicle position to the pre-read target point is short, all types of high-precision map data are pre-read, and if the distance is long, only lane group connection data is pre-read. Therefore, in the map processing device 2 of the present embodiment, the capacity of the high-precision map data held in the device can be reduced, thereby reducing the capacity of the storage that holds the map data in the device and reducing costs. In addition, in the present embodiment, at the pre-read target point that is close to the vehicle position, all types of high-precision map data, that is, various high-precision map data necessary for assistance such as automatic driving, are pre-read, so that the performance of the map processing device 2 is maintained. From the above, in the map processing device 2 of the present embodiment, it is possible to achieve both reduction in the capacity of the storage that holds the map data in the device and maintenance of the performance of the device.

[0105] In the map processing device 2 of this embodiment, when pre-reading (acquiring) map data from the map distribution server 5, if a pre-read target point is not on the planned driving route, only the lane group connection data of the pre-read target point is pre-read. Therefore, in this embodiment, the capacity of high-precision map data held in the device can be further reduced.

[0106] In the map processing device 2 of this embodiment, for points located close to the vehicle, a surrounding image in front of the vehicle is acquired, and high-precision map data is not acquired for lanes not shown in the surrounding image. Therefore, in this embodiment, the capacity of high-precision map data held in the device can be further reduced.

[0107] As described above, the map processing device 2 of this embodiment has a route deviation prediction function. Specifically, when there is a branch point from which deviation may occur on the planned driving route, not only lane group connection data but also various high-precision map data necessary for assistance such as automatic driving, such as lane connection data, are pre-read for points on the route from which deviation may occur that are within a predetermined distance from the branch point (a part of points after the branch point). Therefore, in this embodiment, even if the driving route deviates from the planned driving route, various high-precision map data such as lane connection data are pre-read for a part of the determined new route, so that automatic driving on the new route can be resumed more quickly.

[0108] In the map processing device 2 of this embodiment, when the vehicle deviates from the planned driving route during autonomous driving, a new planned driving route is searched for using the lane group connection data that is read ahead on the route after the deviation. Therefore, in this embodiment, even if the vehicle deviates from the planned driving route during autonomous driving, a new planned driving route can be quickly determined, and an early return to autonomous driving on the new planned driving route is also possible.

[0109] In addition, in the map processing device 2 of this embodiment, when a plurality of candidate routes are obtained in the search process for candidate routes at the time of route deviation, each candidate route is picked up in a predetermined order set in advance, and it is determined whether or not the picked up candidate route is drivable. In this case, in this embodiment, a plurality of types of criteria are provided as criteria for the pick-up order of the settable candidate routes. Specifically, as described above, criteria for the pick-up order are provided, such as the order of least amount of high-precision map data read, the order of shortest distance of the candidate route, the order of shortest time required to reach the destination, and the order considering the search conditions of the initial planned travel route set in the car navigation system 3 or the like. In this embodiment, a predetermined criterion can be selected from these criteria by the driver or the like. Therefore, when such a function is provided, a process for determining a new route according to the needs and priorities of the user can be performed.

[0110] [Various variations] In the above embodiment, a configuration example in which the car navigation system 3 is provided separately from the map processing device 2 has been described, but the present invention is not limited to this. The car navigation system 3 may have the various functions of the map processing device 2 described above. In this case, the car navigation system 3 functions as the map processing device 2. Furthermore, the functions of the car navigation system 3 may be provided in the map processing device 2, in which case there is no need to provide the car navigation system 3. Similarly, the automatic driving control device 4 may have the various functions of the map processing device 2 described above.

[0111] In the above embodiment, an example has been described in which lane connection data, lane attribute data, lane boundary data, lane centerline shape data, lane boundary shape data, and lane group connection data are separately provided as high-precision map data to be processed, but the present invention is not limited to this. Among these high-precision map data, some of the high-precision map data may be collected as one piece of high-precision map data, or one piece of high-precision map data may be divided into multiple pieces of high-precision map data. In addition, as the high-precision map data to be processed, for example, similar map data containing information similar to the various high-precision map data described above, or related data from which the various high-precision map data described above can be derived may be used.

[0112] In the above embodiment, an example was described in which a map processing device 2 was installed in a vehicle equipped with an autonomous driving function, but the present invention is not limited to this, and the map processing device 2 of the above embodiment can also be applied to vehicles that do not have an autonomous driving function.

[0113] In addition, the above-mentioned embodiment has been described in detail and specifically with respect to the configuration of the device in order to easily explain the present invention, and is not necessarily limited to the configuration having all of the described configurations. Furthermore, the present invention may take on various other applications and modifications without departing from the gist of the present invention described in the claims. [Explanation of symbols]

[0114] 1...In-vehicle system, 2...Map processing device, 3...Car navigation system, 4...Automatic driving control device, 5...Map distribution server, 10...Control unit, 11...Memory unit, 12...Sensor unit, 20...Surrounding recognition unit, 21...Self-position estimation unit, 22...Candidate route search unit, 23...Route selection unit, 24...Lane data pre-reading unit, 25...Map access unit, 31...Lane connection / attribute data storage unit, 32...Lane boundary data storage unit, 33...Lane shape data storage unit, 34...Lane group connection data storage unit, 40...Lane group area, 41...Lane group connection data, 42...Lane connection data, 43...Lane attribute data, lane center line shape data, 44...Lane boundary data, lane boundary shape data, 45...Physical structure, 51, 52, 53, 54...Pre-reading target points

Claims

1. a map data pre-reading unit that is capable of acquiring multiple types of map data including lane connection data indicating connection information between lane sections in the direction in which the lanes extend and lane group connection data indicating connection information between lane group sections in the direction in which a lane group made up of one or more lanes extends, and that, when acquiring the map data for a predetermined point ahead of the vehicle, acquires map data of a type corresponding to the conditions of the predetermined point; The condition for the predetermined point is whether or not the predetermined point is a point on a planned travel route of the vehicle; The map data pre-reading unit acquires the lane connection data when the predetermined point is a point on a planned driving route of the vehicle, and acquires the lane group connection data when the predetermined point is a point on a route branching off from the planned driving route of the vehicle. Map processing equipment.

2. The condition for the predetermined point is the distance from the vehicle position to the predetermined point, The map data pre-reading unit acquires the plurality of types of map data if the distance from the vehicle position to the predetermined point is within a predetermined range, and acquires only the lane group connection data if the distance from the vehicle position to the predetermined point is within a specific range that is farther than the predetermined range. The map processing device according to claim 1 .

3. and a route search unit that, when the vehicle deviates from the planned driving route, searches for a candidate route that can become a new planned driving route by referring to the lane group connection data that has already been acquired at a point on the route that the vehicle can travel after the deviation. The map processing device according to claim 1 .

4. The plurality of types of map data includes lane attribute data including information on lane characteristics and driving conditions, and a route determination unit that, when a plurality of candidate routes are obtained by the route search unit, sequentially selects one candidate route from the plurality of candidate routes in accordance with a predetermined selection order, acquires the lane attribute data of the selected candidate route, and determines whether the selected candidate route is suitable for traveling on the host vehicle. The map processing device according to claim 3 .

5. The map data pre-reading unit acquires the lane connection data for a point on a route branching off from a planned driving route of the vehicle and for a part of points after the branching point. The map processing device according to claim 1 .

6. Further, the vehicle is provided with an image capturing device for capturing an image of the surroundings in front of the vehicle, The map data pre-reading unit does not acquire the map data regarding lanes that are not shown in the peripheral image. The map processing device according to claim 1 .

7. the map data pre-reading unit of a map processing device that is capable of acquiring multiple types of map data including lane connection data indicating connection information between lane sections in an extension direction of lanes and lane group connection data indicating connection information between lane group sections in an extension direction of a lane group made up of one or more lanes, when acquiring the map data of a predetermined point ahead of the vehicle, acquiring a type of map data according to conditions of the predetermined point, The condition for the predetermined point is whether or not the predetermined point is a point on a planned travel route of the vehicle; The map data pre-reading unit acquires the lane connection data when the predetermined point is a point on a planned driving route of the vehicle, and acquires the lane group connection data when the predetermined point is a point on a route branching off from the planned driving route of the vehicle. Map processing methods.

Images