JP7378893B2 - Map generation device, map generation method, and map generation program - Google Patents

Description

The present invention relates to a technique for identifying a roadway center line when generating map information from measurement information.

In recent years, development of self-driving cars has been progressing. In order to realize autonomous driving, highly accurate map information is required in addition to various sensors such as cameras and laser radars that are attached to autonomous vehicles. As a method for generating this highly accurate map information, by driving a measurement vehicle called MMS (Mobile Mapping System), we acquire 3D point cloud information of the road surface and roadside equipment, etc. A method of generating map information based on the above has been considered (see Patent Document 1).

The information acquired by MMS is point cloud information that holds three-dimensional position information, and is not map information. Therefore, a plotting process is required to generate map information from point cloud information.
When map information over a wide range is manually generated, the amount of point cloud information to be processed becomes enormous, resulting in enormous work costs. In particular, the cost of creating information on lane markings, which are features that always exist along roads and are necessary map information to realize automated driving, is a problem. Information on lane markings requires not only location information such as where the line is drawn, but also attribute information such as whether it is the center line of the roadway to separate it from oncoming traffic. The roadway center line is also called the center line, upper and lower dividing line, etc. Note that the attribute information includes not only information regarding the line type, such as whether it is a roadway center line, but also information such as the line color, line width, and whether the line is a solid line or a broken line.

If you drive on road information beyond the center line of the road, you may end up in a head-on collision with an oncoming vehicle. Therefore, the location of the center line of the roadway is important information for autonomous driving.

Furthermore, when a map is generated using information acquired by a measurement vehicle such as an MMS, map information is often generated by separately measuring the upper and lower lanes of a road with two-way traffic. This is because if map information of oncoming lanes is also generated, the accuracy of the generated map information may deteriorate due to the influence of distance and shielding.
At this time, when map information is generated from the measurement information obtained by measuring the up lane, the down lane is excluded from the generation of map information. However, if the center line of the road cannot be determined, it will not be possible to determine where the generation target starts. Therefore, the location of the roadway center line is important information from the standpoint of map generation efficiency.

Japanese Patent Application Publication No. 2010-191066

Conventionally, there has been no effective method for determining whether a dividing line is the center line of the roadway.
An object of the present invention is to enable appropriate determination of whether a partition line is a roadway center line.

The map generation device according to this invention includes:
a marking line identification unit that identifies marking lines of the road from road measurement information obtained by a measuring device;
a stop line identification unit that identifies a stop line on the road from the measurement information;
and a center line identification section that identifies a roadway center line based on the stop line identified by the stop line identification section from the lane markings identified by the lane marking identification section.

In this invention, the roadway center line is specified based on the stop line. This makes it possible to appropriately determine whether the dividing line is the roadway center line. As a result, it becomes possible to reduce the work cost required for map generation.

1 is a configuration diagram of a map generation device 10 according to Embodiment 1. FIG. 1 is a flowchart showing the overall operation of the map generation device 10 according to the first embodiment. 5 is a flowchart of a process for identifying a roadway center line in the map generation process according to the first embodiment. FIG. 3 is an explanatory diagram of a process for identifying a stop line that intersects with a travel trajectory according to the first embodiment. FIG. 3 is an explanatory diagram of a process for identifying a roadway center line from a stop line according to the first embodiment. FIG. 3 is a configuration diagram of a map generation device 10 according to a third modification.

Embodiment 1.
***Explanation of configuration***
With reference to FIG. 1, the configuration of a map generation device 10 according to the first embodiment will be described.
The map generation device 10 is a computer.
The map generation device 10 includes hardware such as a processor 11, a memory 12, a storage 13, and a communication interface 14. The processor 11 is connected to other hardware via signal lines and controls these other hardware.

The processor 11 is an IC (Integrated Circuit) that performs processing. Specific examples of the processor 11 include a CPU (Central Processing Unit), a DSP (Digital Signal Processor), and a GPU (Graphics Processing Unit).

The memory 12 is a storage device that temporarily stores information. Specific examples of the memory 12 include SRAM (Static Random Access Memory) and DRAM (Dynamic Random Access Memory).

The storage 13 is a storage device that stores information. A specific example of the storage 13 is an HDD (Hard Disk Drive). In addition, the storage 13 includes a memory card such as an SD (registered trademark, Secure Digital) memory card, a CF (CompactFlash, registered trademark), a NAND flash, a flexible disk, an optical disk, a compact disc, a Blu-ray (registered trademark) disk, a DVD (Digital Versatile Disk), etc. It may be a portable recording medium.

The communication interface 14 is an interface for communicating with an external device. The communication interface 14 is, for example, an Ethernet (registered trademark), USB (Universal Serial Bus), or HDMI (registered trademark, High-Definition Multimedia Interface) port.
The map generation device 10 is connected to devices such as an input device 31, a display device 32, and a reading device 33 via a communication interface 14. The input device 31 is a device for inputting information, and specific examples thereof include a keyboard and a mouse. The display device 32 is a device that displays information, and a specific example is an LCD (Liquid Crystal Display). The reading device 33 is a device that reads information from a storage medium, and a specific example is a DVD drive. Further, the map generation device 10 may be connected to a transmission path such as a LAN (Local Area Network) via the communication interface 14.

The map generation device 10 includes a measurement information acquisition section 21, a map generation section 22, and a map transmission section 23 as functional components. The map generation unit 22 includes a lane marking identification unit 24, a stop line identification unit 25, and a center line identification unit 26 as functional components. The functions of each functional component of the map generation device 10 are realized by software.
The storage 13 stores programs that implement the functions of each functional component of the map generation device 10. This program is read into the memory 12 by the processor 11 and executed by the processor 11. Thereby, the functions of each functional component of the map generation device 10 are realized.

In FIG. 1, only one processor 11 was shown. However, there may be a plurality of processors 11, and the plurality of processors 11 may cooperate to execute programs that implement each function.

***Operation explanation***
The operation of the map generation device 10 according to the first embodiment will be described with reference to FIGS. 2 to 5.
The operation procedure of the map generation device 10 according to the first embodiment corresponds to the map generation method according to the first embodiment. Further, a program that realizes the operation of the map generation device 10 according to the first embodiment corresponds to the map generation program according to the first embodiment.

With reference to FIG. 2, the overall operation of the map generation device 10 according to the first embodiment will be described.
(Step S1: Measurement information acquisition process)
The measurement information acquisition unit 21 acquires road measurement information obtained by a measuring device.
As a specific example, the measurement information acquisition unit 21 acquires measurement information from a measurement device via a transmission path. Alternatively, the measurement information acquisition unit 21 may acquire the measurement information by using the reading device 33 to read measurement information stored in a storage medium such as a DVD.
In the first embodiment, the measurement device is a measurement vehicle equipped with a sensor such as a laser radar. Further, in the first embodiment, the measurement information is point cloud information having three-dimensional position information indicating the latitude, longitude, and height of the road surface, roadside equipment, etc.

(Step S2: Map generation process)
The map generation unit 22 generates map information from the measurement information acquired in step S1.
Specifically, the map generation unit 22 identifies constituent points forming features such as road marking lines and road shoulder edges from point cloud information that is measurement information. Since each point in the point cloud information has three-dimensional position information, when the constituent points forming the feature are identified, the three-dimensional position of the feature is identified. Then, the map generation unit 22 identifies the attribute information of each feature based on the position and size on the road of the constituent points constituting the feature. Thereby, the map generation unit 22 generates map information indicating the location and attribute information of each feature.
At this time, the map generation unit 22 may receive an operation from the input device 31 via the communication interface 14 and edit the map information. That is, the map generation unit 22 may edit the map information based on a manual editing operation.

(Step S3: Map transmission process)
The map transmitter 23 transmits the map information generated in step S2 to the display device 32 via the communication interface 14 for display. The map transmitter 23 may transmit map information not only to the display device 32 but also to other devices such as a user's terminal.

With reference to FIG. 3, a process for identifying a roadway center line in the map generation process according to the first embodiment will be described.
(Step S21: Compartment line identification process)
The marking line identification unit 24 identifies a point sequence, which is a constituent point of the marking line, from the distribution information of the reflection intensity of each point of the point cloud information, which is the measurement information acquired in step S1. Here, the marking line identification unit 24 identifies the roadway center line, lane boundary line, and roadway outside line as the marking lines. Note that the partition line specifying unit 24 may also specify other partition lines such as a flow guide zone.
Specifically, the marking line identification unit 24 divides the point cloud information into a plurality of plate-shaped cross-sectional areas perpendicular to the traveling direction of the measurement vehicle. The lane marking identifying unit 24 identifies a point at the center of gravity of a location where the reflection intensity is higher than the surrounding area by a certain value or more as a point representing the lane marking. The marking line identification unit 24 clusters points representing the marking lines identified from each cross-sectional area, and identifies a sequence of points that constitute each of one or more marking lines existing on the road. Clustering means grouping constituent points that exist in the vicinity. Thereby, the marking line identification unit 24 identifies the three-dimensional position of each of one or more marking lines existing on the road.

(Step S22: Stop line identification process)
The stop line specifying unit 25 specifies constituent points constituting the stop line from the distribution information of the reflection intensity of each point of the point cloud information, which is the measurement information acquired in step S1.
Specifically, the stop line identifying unit 25 excludes points near the lane markings identified in step S21 from the points included in the point cloud information, and extracts points whose reflection intensity is higher than the threshold from the remaining points. . The stop line identification unit 25 clusters the extracted points. The stop line specifying unit 25 calculates a rectangle that includes a cluster that is a collection of clustered points. The stop line specifying unit 25 determines the rectangle to be a stop line when the calculated size of the rectangle satisfies the stop line conditions, and specifies the positions of the four corners of the rectangle from the positions of the points forming the cluster.
The stop line identification unit 25 may use a preset value as the reflection intensity threshold, or may use a value depending on the distribution of the reflection intensity at each point. Furthermore, instead of extracting a point where the reflection intensity is higher than a threshold value, the stop line identification unit 25 may extract a point where the reflection intensity is higher than a certain value compared to the surrounding area.

(Step S23: Center line identification process)
The center line identification unit 26 identifies the roadway center line based on the stop line identified in step S22 from the lane markings identified in step S21.
Specifically, as shown in FIG. 4, the center line identifying unit 26 identifies, among the stop lines identified in step S22, a stop line that intersects with the travel trajectory of the measuring vehicle, which is the measuring device. Thereby, in the case of two-way traffic, the center line identifying unit 26 identifies the stop line in the lane for which map information is to be generated. In FIG. 4, among the stop lines 41A to 41C, the stop line 41A and the stop line 41B are specified as stop lines that intersect with the travel trajectory.
As shown in FIG. 5, the center line specifying unit 26 specifies, as a reference point 42, a point on the near side in the traveling direction of the measurement vehicle on the reference direction side of a rectangle indicating a stop line that intersects with the traveling trajectory. Then, the center line identification unit 26 identifies the partition line closest to the reference point 42 as the roadway center line 43.
Here, the reference direction is right when driving on the left, and left when driving on the right. In other words, in the case of driving on the left, the center line identification unit 26 identifies the corner point on the right side of the rectangle indicating the stop line that intersects with the travel trajectory as the reference point, and identifies the marking line closest to the reference point 42. is specified as the roadway center line 43.

***Effects of Embodiment 1***
As described above, the map generation device 10 according to the first embodiment identifies the roadway center line based on the stop line. This makes it possible to appropriately determine whether the lane marking is a roadway center line without performing determination processes such as determining whether the lane marking is a solid line or a broken line and determining whether there is a median strip. As a result, it becomes possible to reduce the work cost required for map generation.

***Other configurations***
<Modification 1>
In the first embodiment, the measuring device is a measuring vehicle. However, the measurement device is not limited to a measurement vehicle, but may be a device mounted on an aircraft, a satellite, or the like. In this case, instead of the traveling trajectory of the measurement vehicle, the traveling trajectory of the vehicle traveling in the lane to be measured may be used.

<Modification 2>
In the first embodiment, the measurement information is point cloud information. However, the measurement information may also be road image data obtained by a photographing device.
In this case, the marking line identification unit 24 may identify the marking line from the brightness distribution of the image data. Specifically, the lane marking identifying unit 24 may identify a point at the center of gravity of a location where the brightness of the image data is higher than a certain value in the width direction of the road as a point representing the lane marking. Then, the marking line identification unit 24 clusters the points representing the marking lines identified from each cross-sectional area, and identifies a sequence of points that constitute each of the one or more marking lines existing on the road.
Further, the stop line identification unit 25 may identify the stop line from the brightness distribution of the image data. Specifically, the stop line identifying unit 25 may exclude the area near the marking line and extract the area whose brightness is higher than the threshold value from the remaining areas. The stop line identifying unit 25 calculates a rectangle that includes the extracted area, and determines the rectangle to be a stop line if the size of the rectangle satisfies the stop line conditions.

<Modification 3>
In the first embodiment, each functional component is realized by software. However, as a third modification, each functional component may be realized by hardware. Regarding this third modification, the differences from the first embodiment will be explained.

With reference to FIG. 6, the configuration of a map generation device 10 according to modification 3 will be described.
When each functional component is realized by hardware, the map generation device 10 includes an electronic circuit 15 instead of the processor 11, memory 12, and storage 13. The electronic circuit 15 is a dedicated circuit that realizes the functions of each functional component, the memory 12, and the storage 13.

The electronic circuit 15 includes a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, a logic IC, a GA (Gate Array), an ASIC (Application Specific Integrated Circuit), and an FPGA (Field-Programmable Gate Arr). ay) is is assumed.
Each functional component may be realized by one electronic circuit 15, or each functional component may be realized by being distributed among a plurality of electronic circuits 15.

<Modification 4>
As a fourth modification, some of the functional components may be realized by hardware, and other functional components may be realized by software.

The processor 11, memory 12, storage 13, and electronic circuit 15 are referred to as a processing circuit. That is, the functions of each functional component are realized by the processing circuit.

The embodiments and modifications of this invention have been described above. Some of these embodiments and modifications may be implemented in combination. Moreover, any one or some of them may be partially implemented. Note that the present invention is not limited to the embodiments and modifications described above, and various changes can be made as necessary.

10 map generation device, 11 processor, 12 memory, 13 storage, 14 communication interface, 15 electronic circuit, 21 measurement information acquisition unit, 22 map generation unit, 23 map transmission unit, 24 lane marking identification unit, 25 stop line identification unit, 26 center line identification unit, 31 input device, 32 display device, 33 reading device, 41 stop line, 42 reference point, 43 roadway center line.

Claims (3)

The center line of the roadway on the road is determined from the distribution information of the reflection intensity at each point of the point cloud information in the road measurement information including point cloud information having three-dimensional position information obtained by the measuring vehicle while the measuring vehicle is traveling. and a marking line identification unit that identifies marking lines including lane boundary lines and roadway outside lines ;
a stop line identification unit that identifies a stop line on the road from the measurement information;
From the marking line identified by the marking line identification unit, a marking line closer to the reference direction side of the stop line that intersects the travel trajectory of the measurement vehicle among the stop lines identified by the stop line identification unit is determined at the center of the roadway. A map generation device that includes a center line identification unit that identifies the marking line as a roadway line, specifies attribute information such as whether the marking line is a roadway center line, and generates map information of the marking line from the measurement information,
The stop line identifying unit identifies a rectangle indicating the stop line,
The center line identifying unit identifies a point on the reference direction side of the rectangle indicating the stop line as a reference point, and identifies a partition line closest to the reference point as a roadway center line;
In the map generation device, the reference direction is to the right with respect to the traveling direction of the measuring vehicle when driving on the left side, and to the left with respect to the traveling direction of the measuring vehicle when driving on the right side. The marking line identification unit determines the above from the distribution information of the reflection intensity of each point of the point cloud information in road measurement information including point cloud information having three-dimensional position information obtained by the measuring vehicle while the measuring vehicle is traveling. Identify the roadway center line, lane boundary line, and roadway outer line on the road,
a stop line identification unit identifies a stop line on the road from the measurement information;
The center line identification unit identifies , among the specified stop lines, a partition line that is closer to a reference direction side of the stop line that intersects with the travel trajectory of the measured vehicle as a roadway center line. A map generation method that identifies attribute information such as whether the division line is a roadway center line and generates map information of the division line from the measurement information,
The stop line identifying unit identifies a rectangle indicating the stop line,
The center line identifying unit identifies a point on the reference direction side of the rectangle indicating the stop line as a reference point, and identifies a partition line closest to the reference point as a roadway center line;
In the map generation method, the reference direction is to the right with respect to the running direction of the measurement vehicle when driving on the left side, and to the left with respect to the running direction of the measurement vehicle when driving on the right side. The center line of the road on the road is determined from the distribution information of the reflection intensity of each point of the point cloud information in the measurement information of the road that includes point cloud information having three-dimensional position information obtained by the measuring vehicle while the measuring vehicle is traveling. A marking line identification process that identifies marking lines including lane boundary lines and roadway outside lines ;
Stop line identification processing that identifies a stop line on the road from the measurement information;
Among the lane markings identified by the lane marking identification process, a lane line closer to the reference direction side of the stop line that intersects with the travel trajectory of the measured vehicle is selected as the roadway. A computer functions as a map generation device that performs a center line identification process to identify the marking line as a center line, identifies attribute information such as whether the marking line is a roadway center line, and generates map information of the marking line from the measurement information. A map generation program that
In the stop line identification process, a rectangle indicating the stop line is identified,
In the center line identification process, a point on the reference direction side of the rectangle indicating the stop line is identified as a reference point, and a marking line closest to the reference point is identified as a roadway center line;
In the map generation program, the reference direction is to the right with respect to the running direction of the measurement vehicle when driving on the left side, and to the left with respect to the running direction of the measurement vehicle when driving on the right side.

Images