JP7581971B2 - Map data control device for vehicle driving control - Google Patents

Description

The present invention relates to a map data control device for driving control of vehicles such as automobiles.

Map data is necessary to control the driving of a vehicle, and the map data used in controlling the driving of the vehicle is composed of multiple block data. When map data stored in a map server installed in the cloud is used, multiple block data for the area required for the driving control of the vehicle is downloaded from the map server via a network, and map data is formed from the block data and stored in the vehicle's storage device.

For example, the following Patent Document 1 describes a map data control device that updates map data formed from multiple pieces of section data, and is configured to give priority to updating section data for areas where the vehicle travels frequently over section data for other areas. This map data control device makes it possible to give priority to updating section data for areas that are important to the user over section data for other areas.

JP 2015-001471 A

[Problem to be solved by the invention]
In general, vehicle cruise control has various levels of accuracy, such as automatic driving and lane following cruise control. The higher the accuracy of the control, the higher the accuracy of the map data must be, and the higher the accuracy of the map data, the larger the amount of map data. Therefore, when cruise control map data covering all areas required for high-accuracy cruise control is formed, the storage device that stores the map data must have a very large storage capacity. When high-accuracy cruise control is performed, the map data control device described in the above publication also requires the storage device that stores the map data to have a very large storage capacity.

The main objective of the present invention is to provide a map data control device for vehicle cruise control that is improved to reduce the amount of map data without reducing the accuracy of cruise control, thereby reducing the storage capacity of the storage device that stores the map data.

[Means for solving the problems and effects of the invention]
According to the present invention, there is provided a map data control device (10) for vehicle driving control, the map data control device (10) having: a map server (18) that stores map data (map database 26, 30) composed of a plurality of section data (map tiles 64 to 68); a target driving route setting device (navigation device 20) that sets a target driving route (62) for a vehicle (14); and an on-board control unit (driving control ECU 22) configured to receive map data from the map server by wireless communication, acquire the target driving route from the target driving route setting device, form driving control map data (60) for driving the vehicle along the acquired target driving route, and store the driving control map data in a storage device (50).

The map data includes first map data (map tiles 64) and second map data (map tiles 66) having lower accuracy than the first map data, and the control unit (cruise control ECU 22) is configured to obtain information on a current location (Pp) of the vehicle (14), and to form a map of a target driving route (62) and a first area (70) surrounding the target driving route, for a predetermined distance range set in advance from the current location, using the division data of the first map data, and to form a map of a second area (72) farther from the target driving route than the first area, using the division data of the second map data, thereby forming map data (60) for driving control , and the control unit (cruise control ECU 22) is further configured to update the map data (60) for driving control when a distance (L) along the target driving route (62) from the current location of the vehicle (14) to the boundary of the predetermined distance range becomes equal to or less than a reference value (Lc) .

According to the above configuration, a map of the target driving route and a first area surrounding the target driving route is formed using the section data of the first map data, and a map of a second area farther from the target driving route than the first area is formed using the section data of the second map data, thereby forming map data for driving control.

Therefore, compared to when the entire map data for driving control is formed from the first map data, the data size of the map data can be reduced, and the storage capacity of the storage device that stores the map data can be reduced. Also, since the map of the target driving route and the first area around the target driving route is formed from the section data of the first map data, the data size of the map data can be reduced without deteriorating the accuracy of driving control.
According to the above configuration, information on the current location of the vehicle is acquired, and map data for driving control is formed for a predetermined distance range from the current location. Therefore, the amount of map data can be reduced, and the storage capacity of the storage device can be further reduced, compared to when map data for driving control is formed for a distance range from the current location to the destination, for example.
Furthermore, according to the above configuration, when the distance along the target driving route from the current location of the vehicle to the boundary of the predetermined distance range becomes equal to or less than a reference value, the map data for driving control is updated, so that the frequency of updating the map data for driving control can be reduced compared to a case where the map data for driving control is updated regardless of the distance along the target driving route from the current location of the vehicle to the boundary of the predetermined distance range.

[Mode of the invention]
In one aspect of the present invention, the map data includes first map data (map tile 64), second map data (map tile 66) having a lower accuracy than the first map data, and third map data (map tile 68) having a lower accuracy than the second map data, and the control unit (cruise control ECU 22) is configured to form the cruise control map data (60) by forming a map of a first area (70) using the section data of the first map data, forming a map of a second area (72) using the section data of the second map data, and forming a map of a third area (74) that is farther from the target driving route than the second area using the section data of the third map data.

According to the above aspect, the map data for driving control is formed by forming the map of the first area using the section data of the first map data, forming the map of the second area using the section data of the second map data, and forming the map of the third area using the section data of the third map data. Therefore, the decrease in accuracy in the direction away from the target driving route can be made gentler than when the map data for driving control is made up of the first and second areas and the maps of the first and second areas are formed using the section data of two types of map data with different accuracy and data volume.

In another aspect of the present invention, the control unit (cruise control ECU 22) is configured to variably set the reference value (Lc) according to the vehicle speed so that the reference value (Lc) becomes larger as the vehicle speed of the vehicle (14) increases .

According to the above aspect, the reference value is variably set according to the vehicle speed so that the reference value is larger as the vehicle speed is higher . Therefore, by setting the reference value to be larger as the vehicle speed is higher, the map data for cruise control can be updated earlier, and the risk of delays in updating the map data for cruise control can be reduced .

In the above description, in order to aid in understanding the present invention, the names and/or symbols used in the embodiments described below are added in parentheses to the configuration of the invention corresponding to the embodiments. However, each component of the present invention is not limited to the components of the embodiments corresponding to the names and/or symbols added in parentheses. Other objects, other features, and associated advantages of the present invention will be easily understood from the description of the embodiments of the present invention described below with reference to the drawings.

1 is a schematic diagram showing an embodiment of a map data control device for cruise control according to the present invention, which is applied to a vehicle equipped with a cruise control device; 4 is a flowchart showing a routine for generating map data for cruise control and for controlling cruise of a vehicle according to an embodiment. 10 is a flowchart showing a main part of a routine for forming map data for cruise control and for controlling cruise of a vehicle in a modified example. FIG. 4 is a diagram showing a part of an example of map data for driving control in the embodiment. FIG. 1 is a diagram showing an example of a portion of map data for driving control in a conventional map data control device. FIG. 5 is a diagram showing the size of the driving control map data shown in FIG. 4 . FIG. 6 is a diagram showing the size of the map data for driving control shown in FIG. 5 . FIG. 13 is a diagram showing a portion of an example of map data for driving control in a modified example. FIG. 9 is a diagram showing the size of the driving control map data shown in FIG. 8 .

The following describes in detail an embodiment of the present invention with reference to the attached drawings.

<Configuration>
1, a map data control device 10 for driving control according to an embodiment is applied to a vehicle 14 equipped with a driving control device 12. The map data control device 10 includes a map server 18 installed in a cloud 16, a navigation device 20 which is part of the driving control device 12, and a driving control electronic control unit 22. The electronic control unit is abbreviated as ECU (Electric Control Unit).

The map server 18 includes a management server 24, a storage device 28 that stores a database 26 of HD maps, and a storage device 32 that stores a database 30 of ADAS maps. The management server 24 searches and reads the map data stored in the storage devices 28 and 32. The HD maps and ADAS maps are composed of multiple block data (hereafter referred to as "map tiles") that are squares with sides measuring several hundred meters to several kilometers.

The navigation device 20 functions as a target driving route setting device that sets a target driving route (target route) from the current location of the vehicle 14 to the destination when a setting device (not shown in FIG. 1) is operated by the vehicle occupant to set the destination. The navigation device 20 has a built-in storage device that stores the SD map database 34. The SD map is also made up of multiple map tiles that are square with sides measuring several hundred meters to several kilometers.

The navigation device 20 further includes a GNSS (Global Navigation Satellite System) receiver, not shown in FIG. 1. The GNSS receiver receives "signals from artificial satellites (e.g., GNSS signals)" for detecting the current location of the vehicle 14, and obtains the current location (e.g., latitude and longitude) of the vehicle 14 based on the GNSS signals.

The above three types of maps, i.e., HD map, ADAS map and SD map, have the characteristics shown in the following Table 1. Note that HD stands for High Definition, ADAS stands for Advanced Driver-Assistance System, and SD stands for Standard.

As shown in Table 1, HD maps have the highest accuracy and SD maps have the lowest. HD maps have the most content and SD maps have the least content. HD maps have the largest amount of data and SD maps have the smallest amount of data. Furthermore, maps used for autonomous driving must be HD maps, HD maps and ADAS maps enable advanced driving assistance, and driver alerts, such as warning drivers about deviations from a target driving route, can be provided by any of the three types of maps.

The driving control ECU 22 includes a microcomputer, which includes a CPU, ROM, RAM, and an interface (I/F) as shown in FIG. 1. The ROM stores a program for generating map data for driving control and controlling the driving of the vehicle, which corresponds to the flowchart shown in FIG. 2. The CPU reads the control program from the ROM to the RAM, and, as will be described in detail later, generates map data for driving control and controls the driving of the vehicle according to the flowchart shown in FIG. 2.

Connected to the ECU 22 are the navigation device 20, a camera sensor 36 that captures images of the area ahead of the vehicle 14, a radar sensor 38 that emits microwaves ahead of the vehicle 14, and a wireless communication device 40. The wireless communication device 40 wirelessly communicates with the map server 18 via a network 42, and the ECU 22 receives map data, i.e., HD map and ADAS map data, from the map server 18.

Furthermore, the ECU 22 is connected to an electric power steering (EPS) ECU 44, an engine ECU 46, a brake ECU 48, and a storage device 50. The EPS ECU 44 automatically steers the left and right front wheels 14FL and 14FR of the vehicle 14 by controlling an electric power steering device (not shown). The engine ECU 46 controls an engine (not shown) to control the driving force of the driving wheels and change the driving force of the vehicle 14. The brake ECU 48 controls a brake device (not shown) to control the braking force of the left and right front wheels 14FL, 14FR and the left and right rear wheels 14RL, 14RR and change the braking force of the vehicle 14. The storage device 50 is a storage device such as a hard disk drive that can read and write information.

When forming the map data, the ECU 22 obtains information (latitude and longitude) of the current position Pp of the vehicle 14 from the navigation device 20, and obtains the target driving route of the vehicle 14 set by the navigation device 20. The ECU 22 sets the target driving route and its surroundings as a first area, sets an area farther from the target driving route than the first area as a second area, and sets an area farther from the target driving route than the second area as a third area. Next, the ECU 22 obtains HD map data and ADAS map data for the first and second areas from the map server 18 via wireless communication, and obtains SD map data for the third area from the navigation device 20.

The ECU 22 forms the map data for driving control by forming the map of the first area using HD map tile data, the map of the second area using ADAS map tile data, and the map of the third area using SD map tile data. Furthermore, the ECU 22 stores the formed map data for driving control in the storage device 50.

Figure 4 shows a portion of an example of map data 60 for driving control in an embodiment. In Figure 4, 62 indicates the target driving route of the vehicle 14, and 64 to 68 indicate HD map tiles, ADAS map tiles, and SD map tiles, respectively. Note that although the target driving route 62 shown in Figure 4 is linear, it may be curved. Each tile is a square with each side measuring 2 km, but the length of each side may be a value other than 2 km. Also, although the vertical and horizontal sides of each tile are aligned in the north-south and east-west directions, they may be aligned in other directions.

In the example shown in FIG. 4, the first region 70 is a 1 km wide range on both sides of the target driving route 62, the second region 72 is a 2 km wide range on both sides of the first region 70, and the third region 74 is a 2 km wide range on both sides of the second region 72. Note that the map data 60 for driving control has a width of 5 km on both sides of the target driving route 62, but this may be a value other than 5 km. Also, the widths of the first to third regions 70 to 74 may be values other than 2 km, and may be different from each other.

Furthermore, when ECU 22 executes vehicle driving control, it reads map data 60 for driving control within a predetermined range from the current location of vehicle 14 from storage device 50 and stores it in RAM. ECU 22 controls autonomous driving by outputting necessary command signals to EPS ECU 44, engine ECU 46, and brake ECU 48 so that vehicle 14 drives along a target driving route 62 based on the map data for driving control stored in RAM. Information acquired by camera sensor 36 and radar sensor 38 is also used in controlling autonomous driving. Note that autonomous driving may be controlled in any manner known in the art.

<Formation of map data for driving control and vehicle driving control>
Next, a routine for forming map data for driving control and for controlling driving of a vehicle in the embodiment will be described with reference to the flowchart shown in Fig. 2. The control according to the flowchart shown in Fig. 2 is repeatedly executed by a CPU at predetermined time intervals when an ignition switch not shown in Fig. 1 is on and an automatic driving switch not shown in Fig. 1 is on.

First, in step 10, the CPU acquires the target driving route 62 of the vehicle 14 from the navigation device 20 and stores it in the storage device 50. Note that when the CPU executes step 10 after completing step 70 or 90 described below, it reacquires the target driving route 62 of the vehicle 14 from the navigation device 20.

In step 20, the CPU sets the target driving route 62 and its surroundings as a first region 70, for example as shown in FIG. 4. Furthermore, the CPU sets an area farther from the target driving route 62 than the first region 70 as a second region 72, and sets an area farther from the target driving route 62 than the second region 70 as a third region 74.

In step 30, the CPU acquires data of HD map tiles 64 and ADAS map tiles 66 for the first area 70 and second area 72, respectively, by downloading them from the map server 18. The CPU also acquires data of SD map tiles 68 for the third area 74 from the navigation device 20. Furthermore, the CPU applies the acquired data of the three types of map tiles to the corresponding first to third areas 70 to 74 to form map data 60 for driving control, and stores the formed map data 60 for driving control in the storage device 50.

In step 40, the CPU reads out map data 60 for driving control within a predetermined range from the current location of the vehicle 14 from the storage device 50 and stores it in the RAM, and controls the automatic driving so that the vehicle 14 drives along the target driving route 62 based on the map data for driving control.

In step 50, the CPU determines whether or not the vehicle 14 has reached the destination set in the navigation device 20. When the CPU determines that the vehicle 14 has reached the destination, the CPU ends the control according to the flowchart shown in FIG. 2. In contrast, when the CPU determines that the vehicle 14 has not reached the destination, the CPU advances control to step 60.

In step 60, the CPU determines whether or not the vehicle 14 is traveling along the target traveling route 62. When the CPU determines that the vehicle 14 is traveling along the target traveling route 62, the CPU returns control to step 40. In contrast, when the CPU determines that the vehicle 14 is not traveling along the target traveling route 62, the CPU advances control to step 70.

In step 70, the CPU determines whether the vehicle 14 is traveling in the area of the HD map tile 64, i.e., the first area 70. When the CPU determines that the vehicle 14 is traveling in the area of the HD map tile 64, the CPU returns control to step 10. In contrast, when the CPU determines that the vehicle 14 is not traveling in the area of the HD map tile 64, the CPU advances control to step 80.

In step 80, the CPU activates an alarm device not shown in FIG. 1 to generate an alarm to inform the driver that the driving control mode of the vehicle 14 will be changed to a control mode other than autonomous driving. The alarm may be an auditory alarm such as an alarm sound, a visual alarm such as a display, or a physical alarm such as a vibration.

In step 90, the CPU changes the driving control mode of the vehicle 14 to a high-precision driving assistance control mode. In the high-precision driving assistance control mode, the driving of the vehicle 14 is controlled using ADAS map data. The high-precision driving assistance may be any driving assistance that uses ADAS map data to assist the driver in driving so that the vehicle does not deviate from its lane, such as lane keeping control.

As can be seen from the above explanation, according to this embodiment, the map data is made up of map tiles 64 as first map data, map tiles 66 as second map data with lower accuracy than map tile 64, and map tiles 68 as third map data with lower accuracy than map tile 66. A map of the target driving route 62 and a first area 70 around the target driving route is formed using map tiles 64, and a map of a second area 72 that is farther from the target driving route 62 than the first area is formed using map tiles 66. Furthermore, a map of a third area 74 that is farther from the target driving route 62 than the second area is formed using map tiles 68, thereby forming map data 60 for driving control.

Therefore, compared to when the entire driving control map data 60 is formed from map tiles 64 as the first map data, the data size of the map data can be reduced, and the storage capacity of the storage device 50 that stores the map data can be reduced. In addition, because the map of the target driving route 62 and the first area 70 surrounding the target driving route is formed from map tiles 64, the data size of the map data can be reduced without reducing the accuracy of the automated driving.

In addition, according to this embodiment, the map of the first area 70 is formed using map tiles 64, the map of the second area 72 is formed using map tiles 66, and the map of the third area 74 is formed using map tiles 68. Therefore, the decrease in accuracy in the direction away from the target driving route 62 can be made more gradual compared to when the driving control map data 60 is made up of the first and second areas, and the maps of the first and second areas are formed using two types of map tiles with different accuracy and data volume.

Figure 6 is a diagram similar to Figure 4, showing a portion of an example of map data 60 for driving control in a conventional map data control device for driving control. In the case of a conventional map data control device for driving control, a map of the entire area corresponding to the first to third areas is formed by map tiles 64. Therefore, as shown in Figure 7, the amount of data of the map data for the entire area corresponding to the first to third areas becomes large.

In contrast, according to the embodiment, the maps of the first to third regions 70 to 74 are formed using map tiles 64 to 68, respectively, so that the amount of map data for the first and second regions can be reduced compared to the case of a conventional map data control device for driving control (virtual lines), as shown in FIG. 5.

<Modification>
3 is a flow chart showing the main parts of a routine for forming map data for cruise control and for controlling the cruise of the vehicle in a modified example. This modified example is suitable for a case where the distance from the current location of the vehicle 14 to the destination is long. In FIG. 3, the same step numbers as those in FIG. 2 are assigned to steps that are the same as those in FIG. 2.

As can be seen from a comparison between FIG. 3 and FIG. 2, steps 10, 20, 40, 50, 60 to 90 are executed in the same manner as the corresponding steps in the embodiment. After completing step 20, the CPU executes step 35, and after completing step 50, it executes step 55.

In step 35, the CPU downloads and acquires data of HD map tiles 64 and ADAS map tiles 66 for the first and second regions 70 and 72 from the map server 18 for a range of a predetermined distance from the current location of the vehicle 14. The CPU also acquires data of SD map tiles 68 for the third region 74 from the navigation device 20 for a range of the predetermined distance. Furthermore, the CPU applies the acquired data of the three types of map tiles to the corresponding first to third regions 70 to 74 to form map data 60 for driving control, and stores the formed map data 60 for driving control in the storage device 50.

In step 55, the CPU determines whether or not it is necessary to update the driving control map data 60. Whether or not it is necessary to update the map data 60 may be determined, for example, by determining whether or not the distance L along the target driving route 62 from the current location of the vehicle 14 to the boundary of the predetermined distance range is equal to or less than a reference value Lc. The reference value Lc may be a positive constant, but may also be variably set according to the vehicle speed so that the reference value Lc increases as the vehicle speed of the vehicle 14 increases.

According to this modification, the map data for driving control is generated for a predetermined distance range from the current location, and therefore the amount of map data can be reduced and the storage capacity of the storage device 50 can be further reduced, compared to the embodiment in which the map data for driving control 60 is generated for a predetermined distance range from the current location to the destination.
As described above, the determination of whether the map data 60 needs to be updated may be made by determining whether the distance L along the target driving route 62 from the current location of the vehicle 14 to the boundary of the predetermined distance range is equal to or less than the reference value Lc. In this case, the frequency of updating the map data for driving control can be reduced compared to the case where the map data for driving control is updated regardless of the distance along the target driving route from the current location of the vehicle to the boundary of the predetermined distance range.
Furthermore, in the case where the reference value is variably set according to the vehicle speed so that the reference value Lc becomes larger as the vehicle speed of the vehicle 14 increases, the reference value is increased as the vehicle speed increases, whereby the map data for driving control can be updated more quickly and the risk of delays in updating the map data for driving control can be reduced.

Figure 8 is a diagram similar to Figure 4, showing a portion of an example of map data 60 for driving control in a modified example. Comparing Figure 8 with Figure 4, it can be seen that, according to the modified example, the number of map tiles 64-68 along the target driving route 62 can be reduced compared to the embodiment. Therefore, as shown in Figure 9, it can be seen that the data volume of the map data can be reduced compared to the embodiment. Note that in Figure 9, the virtual line indicates the data volume of the map data in the embodiment.

Although the present invention has been described in detail above with respect to a specific embodiment, the present invention is not limited to the above-described embodiment, and it will be apparent to those skilled in the art that various other embodiments are possible within the scope of the present invention.

For example, in the above-described embodiment and modified example, the driving control map data 60 is formed by applying the data of the HD map tile 64, the data of the ADAS map tile 66, and the data of the SD map tile 68 to the first to third regions 70 to 74, respectively. However, the driving control map data 60 may be composed of only the first and second regions. In that case, the data of the HD map tile 64 and the data of the ADAS map tile 66 may be applied to the first and second regions, respectively, or the data of the ADAS map tile 66 and the data of the SD map tile 68 may be applied, or even the data of the HD map tile 64 and the SD map tile 68 may be applied.

In addition, in the above-described embodiment and modified example, the driving control ECU 22 performs driving control of the vehicle 14 and also generates map data for driving control. However, the generation of map data for driving control may be performed by an ECU other than the ECU that performs driving control of the vehicle 14.

Furthermore, in the above-described embodiment and modified example, the data of the SD map tiles 68 is stored in the storage device of the navigation device 20. However, the data of the SD map tiles 68 may also be stored in the storage device of the map server 18. Conversely, the data of the ADAS map tiles 66 may be stored in an on-board storage device.

10...Map data control device for driving control, 12...Driving control device, 14...Vehicle, 18...Map server, 20...Navigation device, 22...Driving control electronic control unit (ECU), 26...HD map database, 30...ADAS map database, 34...SD map database, 60...Map data for driving control, 62...Target driving route, 64...HD map tile, 66...ADAS map tile, 68...SD map tile, 70...First area, 72...Second area, 74...Third area

Claims (3)

A map server that stores map data composed of a plurality of block data;
A target driving route setting device that sets a target driving route for a vehicle ;
an in-vehicle control unit configured to receive the map data from the map server via wireless communication, acquire a target driving route from the target driving route setting device, generate driving control map data for driving the vehicle along the acquired target driving route, and store the driving control map data in a storage device;
A map data control device for vehicle driving control having:
The map data includes first map data and second map data having a lower accuracy than the first map data,
the control unit is configured to obtain information on a current location of the vehicle, and form a map of the target driving route and a first area around the target driving route, using the section data of the first map data, within a range of a predetermined distance set in advance from the current location, and form a map of a second area farther from the target driving route than the first area, using the section data of the second map data, thereby forming the map data for driving control;
The control unit is further configured to update the map data for driving control when a distance along the target driving route from a current location of the vehicle to a boundary of a predetermined distance range becomes equal to or less than a reference value .
A map data control device for vehicle driving control. 2. The vehicle driving control map data control device according to claim 1,
the map data includes first map data, second map data having a lower accuracy than the first map data, and third map data having a lower accuracy than the second map data,
the control unit is configured to form the map data for driving control by forming a map of the first area using the section data of the first map data, forming a map of the second area using the section data of the second map data, and forming a map of a third area farther from the target driving route than the second area using the section data of the third map data.
A map data control device for vehicle driving control. 2. The map data control device for vehicle driving control according to claim 1, wherein the control unit is configured to variably set the reference value according to the vehicle speed so that the reference value becomes larger as the vehicle speed of the vehicle increases .

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