Map information storage device, computer program for storing map information, and map information storage method

Abstract

To provide a map information storage device that can store map information with a reduced number of information to confirm the end of an area for which map information is provided.SOLUTION: A map information storage device stores map information including information about a lane represented by a plurality of lane position information sequences. The map information storage device has a storage unit that stores the lane position information as many lane position information as necessary to control a vehicle in a first section from the current position of the vehicle toward the direction in which the vehicle is traveling, confirms the end of an area for which the map information is provided in a second section from the end of the first section toward the direction in which the vehicle is traveling, and stores less than the number of lane position information necessary to control the vehicle.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a map information storage device, a computer program for storing map information, and a map information storage method. [Background technology]

[0002] An automatic vehicle control system uses high-precision map information of a predetermined section including the current position of the vehicle to control the vehicle (see, for example, Patent Document 1). The automatic control system receives and stores high-precision map information of the predetermined section including the current position of the vehicle from a server.

[0003] High-precision map information includes information on lanes, road curvature, and other road features, among which the largest amount of information is on lanes. A lane is represented by a series of multiple pieces of lane position information that indicate the position of the lane.

[0004] Since the automatic control system cannot control the vehicle in an area where high-precision map information is not available, the system drives the vehicle while checking the end of the area where high-precision map information is available. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-192011 Summary of the Invention [Problem to be solved by the invention]

[0006] However, storing all the information from the current vehicle position to the end of the area for which high-precision map information is provided requires a storage unit with a large storage capacity.On the other hand, in order to confirm the end position of the area for which high-precision map information is provided, it is not necessary to store all the high-precision map information up to the end of the area for which high-precision map information is provided.

[0007] Therefore, an object of the present disclosure is to provide a map information storage device that can store map information while reducing the amount of information for confirming the end of the area for which map information is provided. [Means for solving the problem]

[0008] (1) According to one embodiment, a map information storage device is provided, which stores map information including information about lanes represented by a series of multiple pieces of lane position information, The system is characterized by having a memory unit that stores the number of lane position information required to control the vehicle in a first section from the vehicle's current position in the direction of travel of the vehicle, and that confirms the end of the area for which map information is provided in a second section from the end of the first section in the direction of travel of the vehicle, and stores lane position information less than the number required to control the vehicle.

[0009] (2) Furthermore, in the map information storage device of (1), it is preferable that the storage unit stores lane position information representing the left and right lane dividing lines that divide the lane in the first section, and stores lane position information representing any one of the left lane dividing line, the right lane dividing line, and the center line that represents the center of the lane in the second section.

[0010] (3) In the map information storage device of (2), the storage unit includes information representing a distance from an end of the first section to an end of the second section represented by the lane position information, It is preferable to have a determination unit that determines that the end of the second section is the end of the area for which map information is provided if the distance from the vehicle's current position to the end of the second section is less than a predetermined reference distance.

[0011] (4) In the map information storage device of (3), the lanes in the first and second sections are represented by a series of multiple lane sections, the storage unit stores the length of each of the multiple lane sections, and it is preferable that the distance from the start of the first section to the end of the second section is represented by the sum of the lengths of each of the multiple lane sections between the start of the first section and the end of the second section.

[0012] (5) In the map information storage device of (1) to (4), the lane position information of the second section preferably includes the curvature of the position of the lane having a curvature exceeding a predetermined threshold.

[0013] (6) In the map information storage device of (1) to (5), an input unit is provided for inputting the number of lane position information necessary to control the vehicle in the first section, and for inputting the number of lane position information necessary to confirm the end of the area for which map information is provided in the second section, and it is preferable that the storage unit stores the number of lane position information necessary to control the vehicle input by the input unit in the first section, and stores the number of lane position information necessary to confirm the end of the area for which map information is provided input by the input unit in the second section.

[0014] (7) In the map information storage device of (1) to (5), the map information storage device inputs the number of lane position information required to control the vehicle in the first section and the second section, and has an acquisition unit that acquires the number of lane position information required to control the vehicle in the first section and acquires the number of lane position information required to confirm the end of the area for which map information is provided in the second section, and it is preferable that the storage unit stores the number of lane position information acquired by the acquisition unit required to control the vehicle in the first section, and stores the number of lane position information less than the number required to confirm the end of the area for which map information acquired by the acquisition unit is provided and control the vehicle in the second section.

[0015] (8) According to another embodiment, there is provided a computer program for storing map information, which stores map information including information about lanes represented by a series of multiple pieces of lane position information, and causes a processor to execute a process including inputting a number of pieces of lane position information required to control the vehicle in a first section extending from the current position of the vehicle in the direction of travel of the vehicle, and inputting a number of pieces of lane position information required to confirm the end of an area for which map information is provided in a second section extending from the end of the first section in the direction of travel of the vehicle, and storing the number of pieces of lane position information required to control the vehicle in a storage unit in the first section, and storing the number of pieces of lane position information required to confirm the end of an area for which map information is provided in the storage unit in the second section.

[0016] (9) According to another embodiment, there is provided a map information storage method for storing map information including information about lanes represented by a series of multiple pieces of lane position information, characterized in that the map information storage device inputs a number of pieces of lane position information necessary to control the vehicle in a first section in the direction of travel of the vehicle from the current positions of both vehicles, and inputs a number of pieces of lane position information necessary to confirm the end of an area for which map information is provided in a second section in the direction of travel of the vehicle from the end of the first section, storing the number of pieces of lane position information necessary to control the vehicle in the first section, and storing a number of pieces of lane position information less than the number necessary to confirm the end of the area for which map information is provided and control the vehicle in the second section. [Effects of the Invention]

[0017] The map information storage device according to the present disclosure can store map information with a reduced amount of information for identifying the end of the area for which the map information is provided. [Brief explanation of the drawings]

[0018] [Figure 1]FIG. 2 is a diagram illustrating an outline of the operation of the map information storage device of the present embodiment. [Figure 2] FIG. 10 is a sequence diagram of a map information storage process of the map information storage system including the map information storage device of the present embodiment. [Figure 3] 1 is a schematic configuration diagram of a vehicle in which a map information storage device according to an embodiment of the present invention is implemented; [Figure 4] FIG. 2 is a hardware configuration diagram of a server according to the present embodiment. [Figure 5] 4 is an example of an operational flowchart relating to storage processing of the map information storage device of the present embodiment. [Figure 6] 1A is a diagram illustrating a road section management table, and FIG. 1B is a diagram illustrating a lane section management table. [Figure 7] FIG. 10(A) is a diagram showing some lane sections in a first section, and FIG. 10(B) is a diagram showing a plurality of lane sections in a second section. [Figure 8] 5 is an operational flowchart relating to a determination process of the map information storage device of the present embodiment. [Figure 9] 10 is an example of an operational flowchart of a transmission process of a server. [Figure 10] 10A and 10B are diagrams illustrating a modified example of the map information storage device of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] 1 is a diagram for explaining an outline of the operation of the map information storage device 11 of this embodiment. A map information storage system 1 including the map information storage device 11 of this embodiment has at least one vehicle 10 and a server 70.

[0020] By accessing a radio base station 80 (hereinafter also referred to as a macrocell base station 80), the vehicle 10 is connected to the server 70 via the macrocell base station 80 and the communication network 60. The macrocell base station 80 is connected to the communication network 60 via a gateway (not shown) or the like.

[0021] 1 shows only one vehicle 10, the map information storage system 1 may include multiple vehicles 10. Similarly, multiple macrocell base stations 80 may be connected to the communication network 60.

[0022] The vehicle 10 is equipped with a map information storage device 11 and an automatic control device 14. The map information storage device 11 stores map information used to estimate the current position of the vehicle 10. The map information includes information representing lanes, road curvature, other road features, and the like.

[0023] The automatic control device 14 has an automatic driving mode in which the automatic control device 14 mainly drives the vehicle 10, and a manual driving mode in which the driver mainly drives the vehicle 10. The vehicle 10 is currently being driven by the automatic control device 14 in the automatic driving mode.

[0024] In the example shown in Figure 1, vehicle 10 is traveling on lane 51 of road 50. Lane 51 is divided by lane dividing line 52 and lane dividing line 53. Navigation route R of vehicle 10 indicates traveling on road 50.

[0025] In map information, lane markings are represented by a series of points. The position of each point is expressed, for example, by latitude and longitude coordinates expressed in a world coordinate system. In this specification, information representing the positions of points representing lane markings is also referred to as lane position information. The lane position information may include information representing altitude in addition to latitude and longitude.

[0026] The map information storage device 11 outputs map information including the current position of the vehicle 10 to the automatic control device 14. The automatic control device 14 estimates the position of the vehicle 10 based on this map information, etc., and controls the vehicle. Additionally, as the vehicle 10 moves, the map information storage device 11 receives and stores high-precision map information of a predetermined range including the current position of the vehicle 10 from the server 70.

[0027] 2 is a sequence diagram relating to a map information storage process of the map information storage system 1 including the map information storage device 11 of this embodiment. Every time a transmission request for transmitting map information is received from the vehicle 10, the map information storage system 1 executes the map information storage process in accordance with the sequence diagram shown in FIG.

[0028] First, the map information storage device 11 transmits a transmission request for transmitting map information, together with the current position P and navigation route R of the vehicle 10, to the server 70 via the macrocell base station 80 and the communication network 60 at the map information update time set at a predetermined cycle (step S101).

[0029] Next, the server 70 creates section map information based on the current position P of the vehicle 10, the navigation route R, and the high-precision map information stored in the server 70 (step S102). This section map information includes high-precision map information for a predetermined range extending from the current position P of the vehicle 10 in the direction of travel of the vehicle 10. The range of the map included in the section map information changes as the vehicle 10 moves. The high-precision map information is provided to the server 70 by a map creator.

[0030] Next, the server 70 transmits the section map information to the map information storage device 11 via the communication network 60 and the macrocell base station 80 (step S103).

[0031] The map information storage device 11 receives and stores the section map information (step S104), and ends the series of processes. In the first section D1, which is in the direction of travel of the vehicle 10 from the current position P of the vehicle 10, the section map information includes lane position information for the number of lanes necessary for the automatic control device 14 to control the vehicle 10 along the navigation route R. The end position of the first section D1 is, for example, 200 to 400 m from the current position P of the vehicle 10.

[0032] As shown in Fig. 1, in the section map information for the first section D1, the lane markings 52 and 53 are represented by a series of multiple points S1. In reality, the section map information for the first section D1 includes lane position information that represents a series of pairs of points that represent the lane markings 52 and 53, but in Fig. 1, the pair of points is represented by point S1.

[0033] These multiple points S1 are provided in a number that allows the automatic control device 14 to control the vehicle 10 along the navigation route R. The position of each point S1 is represented by lane position information. The section map information for the first section D1 includes lane position information for multiple points S1 that represent the positions of lane markings 52, 53 included between the start and end of the first section D1.

[0034] As the vehicle 10 moves, the map information storage device 11 outputs map information of a relatively small area including the current position of the vehicle 10 from the section map information included in the first section D1 to the automatic control device 14. The automatic control device 14 controls the vehicle 10 based on this map information, etc.

[0035] Furthermore, in the second section D2, which is located from the end of the first section D1 toward the traveling direction of the vehicle 10, the section map information includes the number of lane position information necessary to confirm the end of the area for which high-precision map information is provided. Furthermore, the section map information includes the number of lane position information less than the number necessary to control the vehicle 10.

[0036] The end of the second section D2 is usually a position that is a map end determination distance away from the current position P of the vehicle 10. The map end determination distance is a distance from the current position P of the vehicle 10 that determines whether map information is provided ahead in the direction of travel. The map end determination distance is, for example, 700 m to 1000 m. The section map information for the second section D2 does not have the number of lane position information necessary for the vehicle 10 to travel along the navigation route.

[0037] 1, the section map information for the second section D2 includes lane position information for point S2 that represents the position of lane markings 52, 53 at the end of the second section D2. The section map information for the second section D2 does not include lane position information that represents lane markings 52, 53 at positions other than the end of the second section D2.

[0038] When high-precision map information is provided from the end of the first section D1 to the position of the map end determination distance, the server 70 creates section map information for the second section D2 from the end of the first section D1 to the position of the map end determination distance based on the high-precision map information.

[0039] If the section map information received from the server 70 includes lane position information for the end position of the second section D2, the map information storage device 11 determines that high-precision map information is provided from the current position P of the vehicle 10 to the end of the second section D2.

[0040] On the other hand, when the vehicle 10 moves from an area where high-precision map information is provided to an area where high-precision map information is not provided, high-precision map information may not be provided for a position that is the map end determination distance away from the current position P of the vehicle 10.

[0041] In this case, the server 70 creates section map information for the second section D2 based on map information up to the end for which high-precision map information is provided, so the end of the section map information for the second section D2 coincides with the end of the area for which high-precision map information is provided.

[0042] If the section map information for the second section D2 received from the server 70 does not include lane position information for a position that is the map end determination distance away from the current position P of the vehicle 10, the map information storage device 11 determines that the end of the second section D2 indicates the end of the area for which high-precision map information is provided.

[0043] If it is determined that the end of the second section D2 indicates the end of the area for which high-precision map information is provided, the map information storage device 11 sends an end notification indicating that the automatic driving mode is ending to the automatic control device 14. The automatic control device 14 transitions to manual driving mode before the vehicle 10 reaches the end of the area for which high-precision map information is provided.

[0044] The section map information for the second section D2 only needs to have the number of pieces of lane position information necessary to confirm the end of the area for which high-precision map information is provided. The section map information for the second section D2 is not used to drive the vehicle 10 along the navigation route R, so it does not need to have as many pieces of lane position information as in the first section D1. Therefore, the map information storage device 11 can significantly reduce the number of pieces of lane position information to be stored, which requires a large storage capacity.

[0045] As described above, the map information storage device 11 of this embodiment can store map information with a reduced amount of information for identifying the end position of the area for which high-precision map information is provided.

[0046] 3 is a schematic configuration diagram of a vehicle 10 in which a map information storage device 11 of this embodiment is implemented. The vehicle 10 includes a camera 2, a communication device 3, a positioning information receiver 4, a navigation device 5, a user interface (UI) 6, the map information storage device 11, a position estimation device 12, an object detection device 13, an automatic control device 14, and the like. The vehicle 10 may further include a ranging sensor (not shown), such as a LiDAR sensor, for measuring distances to objects around the vehicle 10.

[0047] The camera 2, communication device 3, positioning information receiver 4, navigation device 5, UI 6, map information storage device 11, position estimation device 12, object detection device 13, and automatic control device 14 are communicatively connected via an in-vehicle network 15 that complies with a standard such as a controller area network.

[0048] Camera 2 is an example of an imaging unit provided on vehicle 10. Camera 2 is attached to vehicle 10 so as to face forward of vehicle 10. Camera 2 captures camera images showing the environment of a predetermined area ahead of vehicle 10, for example, at a predetermined period. The camera images may show the road included in the predetermined area ahead of vehicle 10 and road features such as lane markings on the road surface. Camera 2 has a two-dimensional detector composed of an array of photoelectric conversion elements sensitive to visible light, such as a CCD or C-MOS, and an imaging optical system that forms an image of the area to be captured on the two-dimensional detector.

[0049] Every time the camera 2 captures a camera image, it outputs the camera image and the time the camera image was captured to the position estimation device 12, the object detection device 13, etc. via the in-vehicle network 15. The camera image is used by the position estimation device 12 in a process of estimating the position of the vehicle 10. The camera image is also used by the object detection device 13 in a process of detecting objects around the vehicle 10.

[0050] The communication device 3 is an example of a device communication unit, and has an interface circuit for connecting the map information storage device 11 and the like to the macrocell base station 80. The communication device 3 is configured to be able to communicate with the server 70 via the macrocell base station 80 and the communication network 60.

[0051] The positioning information receiver 4 outputs positioning information that indicates the current position of the vehicle 10. For example, the positioning information receiver 4 may be a GNSS receiver. Every time the positioning information receiver 4 acquires positioning information at a predetermined reception cycle, the positioning information receiver 4 outputs the positioning information and the time at which the positioning information was acquired to the navigation device 5, the map information storage device 11, etc.

[0052] The navigation device 5 generates a navigation route R from the current position of the vehicle 10 to the destination position based on the navigation map information, the destination position of the vehicle 10 input from the UI 6, and the positioning information indicating the current position of the vehicle 10 input from the positioning information receiver 4. The navigation route R includes information on the positions of right turns, left turns, merging, and branching. In the navigation map, roads are represented by multiple road links connected by nodes. Each node and each road link is identified using identification information. The positions of the road links and nodes are represented, for example, in a world coordinate system with a predetermined position as the origin. The navigation device 5 generates a new navigation route R for the vehicle 10 when a new destination position is set or when the current position of the vehicle 10 deviates from the navigation route R. Every time the navigation device 5 generates a navigation route R, it outputs the navigation route R to the map information storage device 11, the position estimation device 12, etc. via the in-vehicle network 15.

[0053] The UI 6 is an example of a notification unit. The UI 6 is controlled by the navigation device 5, the automatic control device 14, etc., and notifies the driver of driving information of the vehicle 10, a termination notification indicating that the automatic driving mode is ending, etc. The driving information of the vehicle 10 includes information on the current and future routes of the vehicle, such as the current position of the vehicle and a navigation route. The UI 6 may also have an audio output device (not shown) for notifying the driver of the driving information, etc. The UI 6 has a display device 6a, such as a liquid crystal display or a touch panel, for displaying the driving information, etc.

[0054] The UI 6 also generates an operation signal in response to an operation from the driver to the vehicle 10. The UI 6 has, for example, a touch panel or operation buttons as an input device for inputting operation information from the driver to the vehicle 10. Examples of the operation information include a destination location, intermediate destinations, vehicle speed, and other control information for the vehicle 10. The UI 6 outputs the input operation information to the navigation device 5, the automatic control device 14, etc. via the in-vehicle network 15.

[0055] The map information storage device 11 executes control processing, update processing, calculation processing, and determination processing. To this end, the map information storage device 11 has a communication interface (IF) 21, a memory 22, and a processor 23. The communication interface 21, the memory 22, and the processor 23 are connected via a signal line 24. The communication interface 21 has an interface circuit for connecting the map information storage device 11 to the in-vehicle network 15.

[0056] All or part of the functions of the map information storage device 11 are functional modules implemented by, for example, a computer program running on the processor 23. The processor 23 includes a control unit 231, an update unit 232, a calculation unit 233, and a determination unit 234. Alternatively, the functional modules of the processor 23 may be dedicated arithmetic circuits provided in the processor 23. The processor 23 includes one or more central processing units (CPUs) and their peripheral circuits. The processor 23 may further include other arithmetic circuits such as a logic operation unit, a numerical operation unit, or a graphics processing unit. The memory 22 is an example of a storage unit and includes, for example, a volatile semiconductor memory and a non-volatile semiconductor memory. The memory 22 stores application computer programs and various data used in information processing executed by the processor 23.

[0057] The memory 22 stores section map information for estimating the position of a relatively wide area in the first section D1 described above, including the current position of the vehicle 10. The section map information includes three-dimensional information about the road surface, lane position information representing lane markings on the road, information representing the types and positions of other road features and structures, and high-precision map information including the legal road speed limit, etc. The automatic control device 14 controls the vehicle 10 based on the high-precision map information stored in the memory 22. In areas where high-precision map information is not provided, the automatic control device 14 does not allow the vehicle 10 to be driven in autonomous driving mode.

[0058] The memory 22 also stores the number of pieces of lane position information necessary to confirm the end of the area for which high-precision map information is provided in the second section D2 described above.

[0059] Every time positioning information is input from the positioning information receiver 4, the control unit 231 refers to the stored wide-area section map information, and outputs map information of a relatively small area including the current position represented by the positioning information to the position estimation device 12, the object detection device 13, the automatic control device 14, etc. via the in-vehicle network 15. The operation of the map information storage device 11 will be described in detail later.

[0060] The position estimation device 12 estimates the position of the vehicle 10 at the time the camera image was captured, based on road features around the vehicle 10 that are depicted in the camera image. For example, the position estimation device 12 compares lane markings identified in the camera image with lane markings depicted in map information input from the map information storage device 11, to determine the estimated position and estimated azimuth angle of the vehicle 10 at the time the camera image was captured. The position estimation device 12 also estimates the driving lane on the road in which the vehicle 10 is located, based on the lane markings depicted in the map information and the estimated position and estimated azimuth angle of the vehicle 10. Each time the position estimation device 12 determines the estimated position, estimated azimuth angle, and driving lane of the vehicle 10 at the time the camera image was captured, it outputs this information to the object detection device 13, the automatic control device 14, etc.

[0061] The object detection device 13 detects objects around the vehicle 10 and their types (e.g., vehicles) based on camera images. These objects include other vehicles traveling around the vehicle 10. The object detection device 13 tracks the detected objects to determine their trajectories. The object detection device 13 identifies the lane in which the object is traveling based on lane markings shown in map information and the object position. The object detection device 13 outputs object detection information including information indicating the type of the detected object, information indicating its position, and information indicating the traveling lane to the automatic control device 14, etc.

[0062] The automatic control device 14 has an automatic driving mode (e.g., a driving mode of levels 3 to 5) in which the automatic control device 14 takes the lead in driving the vehicle 10, and a manual driving mode (e.g., a driving mode of levels 0 to 2) in which the driver takes the lead in driving the vehicle 10.

[0063] In the autonomous driving mode, the automatic control device 14 controls the steering, driving, braking, and other operations of the vehicle 10 based on map information and detection information from sensors such as the camera 2 mounted on the vehicle 10. Control of the vehicle 10 in the autonomous driving mode is permitted in areas where high-precision map information is provided. In the manual driving mode, the automatic control device 14 controls the steering, driving, braking, and other operations of the vehicle 10 based on the operation of the driver 40. In areas where high-precision map information is not provided, the vehicle 10 is controlled in the manual driving mode.

[0064] In the autonomous driving mode, the automatic control device 14 generates a driving lane plan that indicates the planned driving lanes along which the vehicle 10 will travel, based on map information, the navigation route R, surrounding environment information, and the current position of the vehicle 10. The automatic control device 14 also generates a driving plan that indicates the planned driving trajectory of the vehicle 10 up to a predetermined time in the future, based on the driving lane plan, map information, the current position of the vehicle 10, surrounding environment information, and vehicle state information. Here, the automatic control device 14 generates the driving plan so that the vehicle 10 travels within a lane defined by a pair of lane markings represented by the lane position information. The automatic control device 14 then controls steering, driving, and braking based on the current position of the vehicle 10, the vehicle speed and yaw rate, and the driving plan.

[0065] In FIG. 3, the map information storage device 11, the position estimation device 12, the object detection device 13, and the automatic control device 14 are described as separate devices, but all or some of these devices may be configured as a single device.

[0066] 4 is a hardware configuration diagram of the server 70. The server 70 executes control processing. To that end, the server 70 has a communication interface (IF) 31, a storage device 32, a memory 33, and a processor 34. The communication IF 31, the storage device 32, and the memory 33 are connected to the processor 34 via a signal line 35. The server 70 may further have input devices such as a keyboard and a mouse, and a display device such as a liquid crystal display.

[0067] The communication IF 31 has an interface circuit for connecting the server 70 to the communication network 60. The communication IF 31 is configured to be able to communicate with the vehicle 10 via the communication network 60 and the macrocell base station 80. The communication IF 31 is an example of a server communication unit.

[0068] The storage device 32 includes, for example, a hard disk drive or an optical recording medium and an access device therefor. The storage device 32 stores map information 321 including a navigation map and high-precision map information. The navigation map is a map similar to that of the navigation device 5 of the vehicle 10. The high-precision map information includes lane position information and the like necessary for controlling the vehicle 10. The high-precision map information includes three-dimensional information about the road surface, information indicating the types and positions of other road features and structures, and high-precision map information including the legal road speed limit. The high-precision map information is provided by a cartographer. The storage device 32 may also store a computer program executed on the processor 34 for executing the processes of the server 70 related to the map information storage process. The storage device 32 is an example of a memory unit.

[0069] The memory 33 includes, for example, a volatile semiconductor memory and a non-volatile semiconductor memory. The memory 33 stores various data and computer programs of applications used in information processing executed by the processor 34. Note that the restriction information may be stored in the memory 33. The memory 33 is an example of a storage unit.

[0070] All or part of the functions of the server 70 are functional modules implemented by, for example, a computer program running on the processor 34. The processor 34 has a control unit 341. Alternatively, the functional modules of the processor 34 may be dedicated arithmetic circuits provided in the processor 34. The processor 34 has one or more CPUs (Central Processing Units) and their peripheral circuits. The processor 34 may further have other arithmetic circuits such as a logic arithmetic unit, a numerical arithmetic unit, or a graphics processing unit. Details of the operation of the server 70 will be described later.

[0071] 5 is an example of an operational flowchart relating to storage processing of the map information storage device 11 of this embodiment. The map information storage device 11 executes storage processing in accordance with the operational flowchart shown in FIG. 5 at map information update times that are set at predetermined intervals.

[0072] First, the update unit 232 transmits a transmission request for transmitting section map information to the server 70 together with the current position P of the vehicle 10 and the navigation route R (step S201). The server 70 refers to the high-precision map information, generates section map information for the first section D1 and the second section D2 based on the current position P of the vehicle 10 and the navigation route R, and transmits the section map information to the map information storage device 11.

[0073] Next, the update unit 232 receives section map information from the server 70 (step S202). For the first section D1, the update unit 232 receives section map information including the number of pieces of lane position information necessary to control the vehicle 10. For the second section D2, the update unit 232 receives section map information including the number of pieces of lane position information necessary to confirm the end positions of the area for which map information is provided. The update unit 232 is an example of an input unit.

[0074] Next, the update unit 232 stores the section map information in the memory 22 (step S203), and ends the series of processes. For the first section D1, the update unit 232 stores in the memory 22 section map information including the number of pieces of lane position information necessary to control the vehicle 10. For the second section D2, the update unit 232 stores in the memory 22 section map information including the number of pieces of lane position information necessary to confirm the end positions of the area for which high-precision map information is provided.

[0075] In the section map information, a road is represented as a series of multiple road sections. Each road section is identified using identification information. One or more lanes included in a road are associated with each road section. The positions of lanes, etc. included in the section map information are represented, for example, in a world coordinate system with a predetermined position as the origin. The section map information has a road section management table in which information about road sections included in the map information is registered. Furthermore, one lane on a road is represented as a series of multiple lane sections. The section map information has a lane section management table in which information about lane sections included in the map information is registered.

[0076] 6(A) is a diagram illustrating the road section management table 100. A plurality of road sections included in the section map information are registered in the road section management table 100. The road section management table 100 registers road sections from the road section including the current position of the vehicle 10 to the end of the second section.

[0077] The road section management table 100 has a road section ID column 101, a connection source ID column 102, a connection destination ID column 103, a lane section ID column 104, and a road section information column 105. Identification information for identifying a road section is registered in the road section ID column 101. Identification information for a connection source road section is registered in the connection source ID column 102. Identification information for a connection destination road section is registered in the connection destination ID column 103. Identification information for identifying lanes included in the road section is registered in the lane section ID column 104. Identification information for the road represented by the road section, the location of the road section, road features, information indicating the type and location of structures, the legal speed limit for the road, etc. are registered in the road section information column 105.

[0078] 6(B) is a diagram illustrating the lane section management table 110. A plurality of lane sections included in the section map information are registered in the lane section management table 110. The lane section management table 110 registers lane sections from the lane section including the current position of the vehicle 10 to the lane section including the end of the second section.

[0079] The lane section management table 110 has a lane section ID column 111, a connection source ID column 112, a connection destination ID column 113, a lane position information column 114, a length column 115, and a lane section information column 116. The lane section ID column 111 stores identification information for identifying a lane section. The connection source ID column 112 stores identification information for the lane section of the connection source. The connection destination ID column 113 stores identification information for the lane section of the connection destination. The lane position information column 114 stores lane position information for multiple points representing lane dividing lines included in the lane section. The length column 115 stores the length of the lane dividing line included in the lane section. The lane section information column 116 stores identification information for the lane represented by the lane section, the position of the lane section, etc.

[0080] 7A is a diagram showing lane sections L1 to L4 that are part of the first section D1. In the lane section management table 110, the lane 51 in the first section D1 is represented by a series of multiple lane sections.

[0081] A lane 51 is divided by a left lane marking 52 and a right lane marking 53. In the lane section management table 110, the left lane marking 52 is represented by a series of lane position information of multiple points Sl that represent the left lane marking 52. The right lane marking 53 is represented by a series of lane position information of multiple points Sr that represent the right lane marking 53. In this way, one lane marking (lane) is represented by a series of lane position information of multiple points Sc that represent the center line 54 of the lane 51. Furthermore, in the lane section management table 110, the lane 51 is represented by a series of lane position information of multiple points Sc that represent the center line 54 of the lane 51.

[0082] In the lane position information column 114 of the lane section management table 110 for the first section D1, lane position information for point Sl, lane position information for point Sr, and lane position information for point Sc are registered for each lane section.

[0083] In the lane section management table 110, the lane position information column 114 for each lane section of the first section D1 registers the number of points Sl representing the left lane dividing line 52, points Sr representing the right lane dividing line 53, and points Sc representing the center line 54 at which the automatic control device 14 can drive the vehicle 10 along the lane 51.

[0084] The automatic control device 14 generates a driving plan based on the lane position information of the left lane marking 52 and the right lane marking 53 registered in the lane position information field 114. The automatic control device 14 may also generate a driving plan by referring to the lane position information of the center line 54 of the lane.

[0085] 7(B) is a diagram showing multiple lane sections Lm to Ln in the second section D2. In the lane section management table 110, the lane 51 in the second section D2 is also represented as a series of multiple lane sections. Lane section Lm is located at the beginning of the second section D2, and lane section Ln is located at the end of the second section D2.

[0086] Regarding the lane position information of the second section D2, the lane section management table 110 has the lane position information registered only in the lane position information column 114 of the lane section Ln at the end position of the second section D2.

[0087] The lane position information field 114 for the lane section Ln registers lane position information for point Sc, which represents the center line 54 of the lane 51. Specifically, the lane position information field 114 for the lane section Ln registers only lane position information for point Sc, which is the end position of the lane section Ln. Note that the lane position information field 114 for the lane section Ln may also register lane position information representing the position of point Sr of the right lane marking. Furthermore, the lane position information field 114 for the lane section Ln may also register lane position information representing the position of point Sl of the left lane marking.

[0088] In the lane section management table 110, no lane position information is registered in the lane position information column 114 from the lane section Lm at the start of the second section D2 to the lane section Ln-1 just before the end of the second section D2. This allows for a significant reduction in the amount of lane position information for the second section D2 stored in the memory 22.

[0089] Next, the determination process in which the map information storage device 11 determines the end position of the area for which map information is provided based on the lane position information of the end position of the second section D2 will be described below with reference to FIG.

[0090] 8 is an operational flowchart relating to the determination process of the map information storage device 11 of this embodiment. The map information storage device 11 executes the determination process according to the operational flowchart shown in FIG. 8 every time it receives new section map information.

[0091] First, the calculation unit 233 calculates the distance G from the current position of the vehicle 10 to the end of the second section D2 (step S301). The end position of the lane section Ln at the end of the second section D2 is represented by lane position information registered in the lane section management table 110. In the lane section management table 110, the lane position information for only the lane section at the end of the second section D2 is registered. The calculation unit 233 refers to the length column 115 of the lane section management table 110 stored in the memory 22, and calculates the sum of the lengths of the multiple lane sections between the start of the first section D1 and the end of the second section for the lane 51 on which the vehicle 10 is traveling as the distance G. The distance G includes the length of the lane section including the start of the first section D1 and the length of the lane section including the end of the second section.

[0092] Next, the determination unit 234 determines whether the distance G is shorter than the map end determination distance (step S302). The automatic control device 14 cannot accurately control the vehicle 10 in an area for which high-precision map information is not available. Therefore, the map information storage device 11 checks the end of an area for which high-precision map information is available.

[0093] If the distance G is shorter than the map end determination distance (step S302-Yes), the determination unit 234 determines that the end position of the second section D2 indicates the end position of the area for which high-precision map information is provided (step S303), and ends the series of processes. The fact that the distance G is shorter than the map end determination distance means that high-precision map information is not provided beyond the end position of the second section D2.

[0094] The determination unit 234 sends an end notification indicating that the autonomous driving mode is ending to the automatic control device 14, along with the distance G. The automatic control device 14 transitions to manual driving mode before the vehicle 10 reaches the end of the area for which high-precision map information is provided. The driver drives the vehicle 10 in manual driving mode. Alternatively, the automatic control device 14 may stop the vehicle 10 before the vehicle 10 reaches the end of the area for which high-precision map information is provided.

[0095] On the other hand, if the distance G is not shorter than the map end determination distance (step S302-No), the series of processes ends. The fact that the distance G is not shorter than the map end determination distance means that high-precision map information is being provided even at a position that is the map end determination distance away from the current position of the vehicle 10. The automatic control device 14 can drive the vehicle 10 in automatic driving mode.

[0096] Next, the processing of the server 70 related to the map information storage processing will be described below with reference to Fig. 9. Fig. 9 is an example of an operational flowchart of the transmission processing of the server 70. Every time the server 70 receives a transmission request from the map information storage device 11, the server 70 executes the transmission processing in accordance with the operational flowchart shown in Fig. 9.

[0097] The control unit 341 generates a road section management table by referring to the map information 321 stored in the storage device 32, based on the current position P of the vehicle 10 and the navigation route R (step S401). The map information 321 includes a navigation map and high-precision map information.

[0098] The control unit 341 creates a road section management table of roads from the current position P of the vehicle 10 to the position at the map end determination distance by referring to the navigation route R. On the navigation map, roads are represented by a plurality of road links connected by nodes. The roads from the current position P of the vehicle 10 to the position at the map end determination distance are represented by a series of a plurality of road links.

[0099] The control unit 341 associates each of the road links on the navigation route R with the road sections of the high-precision map information, and generates a road section management table that indicates the road sections from the current position P of the vehicle 10 to the position at the map end determination distance.

[0100] Next, the control unit 341 creates a lane section management table for the road from the current position P of the vehicle 10 to the position at the map end determination distance based on the high-precision map information, by referring to the lane section ID column of the road section management table (step S402).

[0101] Next, the control unit 341 creates section map information having a road section management table, a lane section management table, and high-precision map information associated with each table (step S403). For the first section D1, the control unit 341 creates the section map information so that it includes the number of pieces of lane position information necessary to control the vehicle 10. Specifically, the control unit 341 creates the lane section management table so that it includes the same number of pieces of lane position information as the lane position information included in the high-precision map information.

[0102] Furthermore, the control unit 341 creates the section map information for the second section D2 so as to include the number of pieces of lane position information necessary to confirm the end positions of the area for which high-precision map information is provided. Furthermore, the control unit 341 creates the section map information for the second section D2 so as to include the number of pieces of lane position information less than the number necessary to control the vehicle 10.

[0103] Specifically, the control unit 341 creates the lane section management table to include only the lane position information of the lane section at the end position of the second section D2. For example, the control unit 341 creates the lane section management table to include only the lane position information of the center line of the lane section at the end position of the second section D2. Preferably, the control unit 341 creates the lane section management table to include only the lane position information of the end position of the center line of the lane section at the end position of the second section D2.

[0104] On the other hand, there may be cases where high-precision map information is not provided up to a position that is the map end determination distance away from the current position P of the vehicle 10. In this case, high-precision map information is provided for the first section, but high-precision map information is considered to be provided up to the middle of the second section. The control unit 341 then creates a road section management table and a lane section management table based on the map information up to the end for which high-precision map information is provided. The end of the section map information for the second section D2 coincides with the end of the area for which high-precision map information is provided. As described above, the control unit 341 creates a lane section management table for the second section D2 so that it includes only lane position information for the lane section at the end of the second section D2.

[0105] Next, the control unit 341 transmits the section map information to the map information storage device 11 (step S404), and ends the series of processes.

[0106] As described above in detail, the map information storage device of this embodiment can store map information with a reduced amount of information for identifying the end positions of areas for which high-precision map information is provided.

[0107] Next, a modified example of the map information storage device 11 of the above-described embodiment will be described below with reference to Fig. 10. Fig. 10 is a diagram for explaining a modified example of the map information storage device 11 of the embodiment.

[0108] In this variant, in the second section D2, the lane position information includes the curvature of the position of a lane having a curvature exceeding a predetermined threshold. The map information storage device 11 transmits the current speed of the vehicle 10 to the server 70 along with a transmission request for section map information. The server 70 determines whether there is a lane position where lateral acceleration of the vehicle 10 exceeds a predetermined reference value, based on the speed of the vehicle 10, the navigation route R, and the high-precision map information. If there is a lane position where lateral acceleration exceeding the predetermined reference value occurs, the server 70 adds the lane position information including the curvature of this lane position to the section map information of the second section D2. Hereinafter, the lane position for which a curvature radius is provided is also referred to as a sharp curve position.

[0109] 9, in the second section D2, lane position information of point S21, which is a sharp curve position, as well as point S2, which is the end point, is stored in the memory 22 of the map information storage 11. In this way, the map information storage device 11 may store lane position information of points other than those for confirming the end point of the area for which high-precision map information is provided.

[0110] The control unit 231 of the map information storage device 11 refers to the section map information of the second section D2, and if there is lane position information including curvature, notifies the automatic control device 14 of the sharp curve position and curvature.

[0111] The automatic control device 14 generates a driving plan so that the lateral acceleration occurring in the vehicle 10 will be within a predetermined limit when the vehicle 10 reaches a sharp curve position. If the automatic control device 14 estimates that the lateral acceleration occurring in the vehicle 10 will exceed a reference value if the vehicle 10 travels at its current speed, it generates a driving plan so that the vehicle 10 will decelerate in advance.

[0112] According to the above-described modified example, the map information storage device 11 can provide safe driving and comfortable travel.

[0113] In the present disclosure, the map information storage device, the computer program for storing map information, and the map information storage method of the above-described embodiments can be modified as appropriate without departing from the spirit of the present disclosure. Furthermore, the technical scope of the present disclosure is not limited to those embodiments, but extends to the inventions set forth in the claims and their equivalents.

[0114] For example, the method for determining the end position of the area for which high-precision map information is provided is not limited to the above-described embodiment. For example, if high-precision map information is not provided for the location of the map information determination distance, the server may transmit section map information that does not include lane position information for the end position of the second section corresponding to the location of the map information determination distance to the map information storage device. The section map information may have a flag indicating whether or not lane position information is available for the end position of the second section. The map information storage device may determine the end of the area for which high-precision map information is provided based on whether or not lane position information is available for the end of the second section. In this case, when it is first determined that there is no lane position information for the end of the second section, the determination unit may determine that the end of the second section in the previous determination is the end of the area for which high-precision map information is provided.

[0115] In the above-described embodiment, the map information storage device stores the section map information created by the server. However, the map information storage device may also create the section map information. In this case, the server transmits high-precision map information for the first and second sections to the map information storage device. The high-precision map information includes a number of pieces of lane position information required to control the vehicle. An update unit of the map information storage device inputs the high-precision map information for the first and second sections. The update unit then acquires a number of pieces of lane position information required to control the vehicle for the first section, and acquires a number of pieces of lane position information required to confirm the end position of the area for which map information is provided for the second section. The update unit stores in memory the acquired number of pieces of lane position information required to control the vehicle for the first section, and stores in memory the acquired number of pieces of lane position information required to confirm the end position of the area for which map information is provided for the second section. The update unit is an example of an acquisition unit. If high-precision map information has not been provided up to the middle of the second section, the update unit creates the section map information based on map information up to the end for which high-precision map information is provided.

[0116] Furthermore, in the above-described embodiment, lane information for the end position of the center line of the final lane section of the second section is stored in the memory as lane position information required to confirm the end position of the area for which map information is provided. The memory may be configured to store any of lane position information for the end positions of the left lane marking, right lane marking, and center line for the final lane section of the second section. In this case, the map information storage device confirms the end position of the area for which map information is provided based on any of the lane position information for the end positions of the left lane marking, right lane marking, and center line. [Explanation of symbols]

[0117] 1. Map information storage system 2 Cameras 3. Communications equipment 4. Positioning information receiver 5. Navigation devices 6 User Interface 6a Display device 10 vehicles 11 Map information storage device 21 Communication Interface 22 Memory 23 processors 231 Control Unit 232 Update Department 233 Calculation Unit 234 Judgment section 12 Position estimation device 13 Object detection device 14 Automatic control devices 15 In-vehicle network 70 servers

Claims

1. A map information storage device that stores map information including information about lanes represented by a series of a plurality of pieces of lane position information, a storage unit that stores a number of pieces of lane position information required to control the vehicle in a first section extending from the current position of the vehicle in the direction of travel of the vehicle, and that stores a number of pieces of lane position information required to confirm the end of an area for which the map information is provided, but less than the number required to control the vehicle, in a second section extending from an end of the first section in the direction of travel of the vehicle; A map information storage device characterized by:

2. 2. The map information storage device according to claim 1, wherein the storage unit stores the lane position information representing left and right lane dividing lines that divide lanes in the first section, and stores the lane position information representing any one of a left lane dividing line, a right lane dividing line, and a center line that represents the center of a lane in the second section.

3. the storage unit includes information representing a distance from a start point of the first section to an end point of the second section represented by the lane position information, 3. The map information storage device according to claim 2, further comprising a determination unit that, if the distance from the current position of the vehicle to the end of the second section is less than a predetermined reference distance, determines that the end of the second section is the end of the area for which the map information is provided.

4. The lanes in the first section and the second section are represented by a series of multiple lane sections, the storage unit stores the lengths of each of a plurality of lane sections; 4. The map information storage device according to claim 3, wherein the distance from the start of the first section to the end of the second section is expressed as the sum of the lengths of each of a plurality of lane sections between the start of the first section and the end of the second section.

5. The map information storage device according to claim 1 , wherein the lane position information of the second section includes a curvature of a lane position having a curvature exceeding a predetermined threshold value.

6. an input unit for inputting the lane position information as many times as necessary to control the vehicle in the first section, and inputting the lane position information as many times as necessary to confirm an end of an area for which the map information is provided in the second section, 2. The map information storage device according to claim 1, wherein the storage unit stores, in the first section, the lane position information in a number necessary to control the vehicle input by the input unit, and, in the second section, the lane position information in a number necessary to confirm an end of an area to which the map information input by the input unit is provided, but less than the number necessary to control the vehicle.

7. an acquisition unit that inputs the lane position information as many times as necessary to control the vehicle in the first section and the second section, acquires the lane position information as many times as necessary to control the vehicle in the first section, and acquires the lane position information as many times as necessary to confirm an end of an area in which the map information is provided in the second section, 2. The map information storage device according to claim 1, wherein the storage unit stores, in the first section, the lane position information acquired by the acquisition unit as many times as necessary to control the vehicle, and, in the second section, the lane position information that is a number necessary to confirm an end of an area provided by the map information acquired by the acquisition unit, but is less than a number necessary to control the vehicle.

8. A computer program for storing map information that stores map information including information about lanes represented by a series of multiple pieces of lane position information, inputting the lane position information as many times as necessary to control the vehicle in a first section extending from the current position of the vehicle toward the traveling direction of the vehicle, and inputting the lane position information as many times as necessary to confirm the end of the area for which the map information is provided in a second section extending from the end of the first section toward the traveling direction of the vehicle; In the first section, the storage unit stores the lane position information in a number necessary for controlling the vehicle, and in the second section, the storage unit stores the lane position information in a number necessary for confirming an end of an area for which the map information is provided, but less than a number necessary for controlling the vehicle.

2. A computer program for storing map information, the computer program causing a processor to execute a process including:

9. A map information storage method for storing map information including information about lanes represented by a series of a plurality of pieces of lane position information, comprising: A map information storage device inputting the lane position information as many times as necessary to control the vehicle in a first section extending from the current position of the vehicle toward the traveling direction of the vehicle, and inputting the lane position information as many times as necessary to confirm the end of the area for which the map information is provided in a second section extending from the end of the first section toward the traveling direction of the vehicle; In the first section, the lane position information is stored in a number necessary for controlling the vehicle, and in the second section, the lane position information is stored in a number necessary for confirming an end of an area for which the map information is provided, but less than a number necessary for controlling the vehicle. A map information storage method comprising:

Images