Method and system for automatically constructing a lane centerline

Abstract

The application provides a method and system for automatically constructing a lane center line, comprising the following steps: S1: acquiring road surface data and intersection surface data of a lane, and dividing the lane into lane lines and road tracks; S2: adjusting the direction of the lane lines so that the direction of the lane lines is consistent with the direction of the road tracks; S3: dividing the road into two directionally different sub-directional roads according to the adjusted lane lines; S4: generating a broken line according to the positions of road changes and broken places and in combination with a road trend line; S5: dividing into road sections and generating a lane center line according to the lane lines and the broken line; and S6: generating an intersection lane center line according to the relationship between the lane center lines and directional arrows of entrances and exits and road rules at the intersection surface. By generating a broken line in combination with a road trend line, even if the road has a high degree of change, the road trend line is fully considered, and the broken line is generated through clustering, so that the accuracy of the broken line is improved, and the lane center line can be more accurately constructed.

Description

Technical Field

[0001] This invention relates to the field of navigation map technology, and more specifically, to a method and system for automatically constructing lane centerlines. Background Technology

[0002] Lane centerlines are the core data of lane-level high-precision maps. They are not obtained directly from the visible road, but need to be obtained by combining the semantic information, topological relationships and traffic information of the road. They are the key expression of the semantic and topological information of high-precision maps, and provide prior knowledge for subsequent intelligent driving. They play a key role in connecting the preceding and following steps. Automatically constructing lane centerlines is an important step in the entire automated high-precision map making process.

[0003] Existing methods for generating lane centerlines perform well on straight roads, but their accuracy is low on curved roads and sharp bends. When constructing lane centerlines, they only consider the horizontal break lines. When the road changes in height, the break lines become inaccurate, resulting in inaccurate lane centerlines. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method and system for automatically constructing lane centerlines.

[0005] In a first aspect, a method for automatically constructing lane centerlines is provided, the method comprising:

[0006] Step S1: Obtain the road surface data and intersection surface data of the lane to be constructed, and divide them into lane lines and road trajectories;

[0007] Step S2: Based on the lane lines and road trajectory, adjust the direction of the lane lines to make them consistent with the direction of the road trajectory, dividing them into two lane lines.

[0008] Step S3: Based on the direction of the adjusted lane lines, divide the road into two separate directional roads;

[0009] Step S4: Based on the roads in different directions, generate break lines according to the locations of road changes and breaks, and in conjunction with road trend lines;

[0010] Step S5: Divide the road into segments based on the lane lines and their corresponding break lines, and generate lane center lines in accordance with road rules;

[0011] Step S6: At the intersection, generate the intersection lane center lines by combining the relationship between the lane center lines and directional arrows of the entrances and exits, as well as the road rules.

[0012] Preferably, generating the break line specifically includes:

[0013] Step S4.1: Using the road trend line and lane line endpoints, draw a perpendicular line from the trend line direction at the endpoints;

[0014] Step S4.2: Cluster the vertical lines according to the distance between the lane lines and merge them into a single break line;

[0015] Step S4.3: Sort the broken lines according to the direction of the road trend line;

[0016] Step S4.4: Divide the road into segments according to the order of the pre-sorted break lines;

[0017] Step S4.5: Arrange the lane lines in the road segment in order from top to bottom;

[0018] Step S4.6: Iterate through the two adjacent lane lines from top to bottom, determine the trend of the distance change between the upper lane line and the lower lane line, extract the coordinates of the inflection point of the change, and add a new break line according to the coordinate position.

[0019] Step S4.7: Combine the new break line and the old break line, and repeat steps S4.1 to S4.3.

[0020] Preferably, the generation of the lane centerline specifically includes:

[0021] Step S5.1: Using the break line and following steps S4.4 and S4.5, divide the road and lane lines into sorted road segments and lane lines;

[0022] Step S5.2: Iterate through the two adjacent lane lines from top to bottom, determine whether the distance between the upper lane line and the lower lane line meets the width of the generated lane center line and whether it meets the ground feature constraints; for the two lane lines that meet the corresponding conditions, generate multiple center points in sequence according to the order of the points constituting the lane lines, and finally fit and generate the lane center line.

[0023] Preferably, the generation of the lane centerline further includes:

[0024] By utilizing the front-to-back relationship between the road segments, and by determining whether the lane center lines between adjacent front-to-back road segments are generated by the same or two lane lines, the corresponding front-to-back endpoints of the two lane center lines are adjusted to ensure the upstream and downstream connectivity of the lane center lines.

[0025] When there are non-connected center lines between adjacent lane center lines, it is necessary to determine the connection relationship between the adjacent lane center lines and whether the current lane center line can connect to the connection point of the adjacent lane center lines. If the relevant conditions, such as not crossing solid lines or hitting curbs, are met, then the connection can be made.

[0026] Preferably, generating the intersection lane centerline specifically includes:

[0027] Step S6.1: Using the intersection data and the lane centerline, determine the centerline of the lane entering the intersection and the centerline of the lane exiting the intersection;

[0028] Step S6.2: Combining the intersection relationship between the directional arrow and the lane center line, add the actual left and right relationship of the lane to determine the turning relationship of the lane center line entering the intersection;

[0029] Step S6.3: Calculate the corresponding steering method based on the angle between the center line of the lane entering the intersection and the center line of the lane exiting the intersection, and then determine whether it is consistent with the steering relationship of the center line of the lane entering the intersection.

[0030] Step S6.4: Combining the relevant lines in the intersection, including lane lines, curb lines, and safety island boundaries, the front and rear endpoints of the relevant lines can cut off part of the intersection lane center line on both sides of the relevant lines;

[0031] The center lines of the lanes at the cut-off points converge to form a common center line, which then establishes a left-right relationship with the lane lines, curb lines, and safety island boundary lines that cut it off. At the same time, the upstream and downstream relationships of the cut-off lane center lines are adjusted.

[0032] Preferably, in step S6.3, it is determined whether the detection is consistent. If they are consistent, the center line connecting the center line of the lane entering the intersection and the center line of the lane exiting the intersection is calculated.

[0033] The calculation of the connection centerline uses Bézier curve fitting or catmull Fitting or intersection trajectory extraction.

[0034] Secondly, a system for automatically constructing lane centerlines is provided, including:

[0035] Module M1: Acquires road surface data and intersection surface data of the lane to be constructed, and divides them into lane lines and road trajectories;

[0036] Module M2: Adjusts the direction of the lane lines based on the lane lines and road trajectory, dividing the lane lines into two directions to ensure they align with the direction of the road trajectory;

[0037] Module M3: Based on the direction of the adjusted lane lines, the road is divided into two separate directional roads;

[0038] Module M4: Based on the roads in the given directions, and according to the locations of road changes and breaks, and in conjunction with the road trend lines, generate break lines;

[0039] Module M5: Based on the lane lines and their corresponding break lines, divide the road into segments and generate lane center lines in accordance with road rules;

[0040] Module M6: At the intersection, it generates the intersection lane center lines by combining the relationship between the lane center lines and directional arrows of the entrances and exits, as well as the road rules.

[0041] Preferably, generating the break line specifically includes:

[0042] Module M4.1: Using the road trend line and lane line endpoints, draw a perpendicular line from the trend line direction at the endpoint;

[0043] Module M4.2: Based on the distance between lane lines, cluster the vertical lines and merge them into a single break line;

[0044] Module M4.3: Sort the break lines according to the direction of the road trend line;

[0045] Module M4.4: Divides the road into segments according to the order of the pre-sorted break lines;

[0046] Module M4.5: Sorts lane markings in a road segment in a top-to-bottom order;

[0047] Module M4.6: Iterate through two adjacent lane lines from top to bottom, determine the trend of distance change between the upper lane line and the lower lane line, extract the coordinates of the inflection point of the change, and add a new break line according to the coordinate position;

[0048] Module M4.7: Combines the new and old break lines, and re-executes modules M4.1 to M4.3.

[0049] Preferably, the generation of the lane centerline specifically includes:

[0050] Module M5.1: Using break lines and in accordance with Modules M4.4 and M4.5, the road and lane lines are divided into sorted road segments and lane lines;

[0051] Module M5.2: Iterates through two adjacent lane lines from top to bottom, determines whether the distance between the upper lane line and the lower lane line meets the width of the generated lane center line, and whether it meets the ground feature constraints; for two lane lines that meet the corresponding conditions, multiple center points are generated sequentially according to the order of the points constituting the lane lines, and finally the lane center line is generated by fitting.

[0052] Preferably, the generation of the lane centerline further includes:

[0053] By utilizing the front-to-back relationship between the road segments, and by determining whether the lane center lines between adjacent front-to-back road segments are generated by the same or two lane lines, the corresponding front-to-back endpoints of the two lane center lines are adjusted to ensure the upstream and downstream connectivity of the lane center lines.

[0054] When there are non-connected center lines between adjacent lane center lines, it is necessary to determine the connection relationship between the adjacent lane center lines and whether the line can connect to the connection point of the adjacent lane center lines. If the relevant conditions, such as not crossing solid lines or hitting curbs, are met, then the connection can be made.

[0055] Preferably, generating the intersection lane centerline specifically includes:

[0056] Module M6.1: Utilizes the intersection relationship between intersection surface data and lane center lines to determine the center lines of lanes entering and exiting the intersection;

[0057] Module M6.2: Combines the intersection relationship between the directional arrow and the lane center line, adds the actual left and right relationship of the lane, and determines the turning relationship of the lane center line when entering the intersection;

[0058] Module M6.3: Calculates the corresponding steering method based on the angle between the center line of the lane entering the intersection and the center line of the lane exiting the intersection, and then determines whether it is consistent with the steering relationship of the center line of the lane entering the intersection.

[0059] Module M6.4: Combines relevant lines including lane lines, curb lines, and safety island boundaries in intersections, and the front and rear endpoints of the relevant lines can cut off part of the intersection lane center line on both sides of the relevant lines;

[0060] The center lines of the lanes at the cut-off points converge to form a common center line, which then establishes a left-right relationship with the lane lines, curb lines, and safety island boundary lines that cut it off. At the same time, the upstream and downstream relationships of the cut-off lane center lines are adjusted.

[0061] Preferably, in module M6.3, it is determined whether the detection is consistent. If they are consistent, the center line connecting the center line of the lane entering the intersection and the center line of the lane exiting the intersection is calculated.

[0062] The calculation of the connection centerline uses Bézier curve fitting or catmull Fitting or intersection trajectory extraction.

[0063] Compared with the prior art, the present invention has the following beneficial effects:

[0064] 1. This invention generates a break line by combining road trend lines at road changes. Even if there are changes in road height, the road trend lines are fully considered and break lines are generated through clustering, which improves the accuracy of the break line and allows for more accurate construction of lane center lines.

[0065] 2. This invention divides the road and lane lines into segments of a certain range by breaking the lines. Within these segments, the road can be approximated as a straight line. Compared with constructing lane center lines for complete road segments, this invention can better improve the accuracy and computational efficiency of constructing lane center lines. Attached Figure Description

[0066] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0067] Figure 1 A flowchart of the method for automatically constructing lane centerlines in this application;

[0068] Figure 2 for Figure 1 A schematic diagram of a scenario from the embodiment shown in the process flow;

[0069] Figure 3 The image shows the effect of using the method for automatically constructing lane centerlines in this application;

[0070] Figure 4 The image shows the effect of using the method for automatically constructing lane centerlines in this application;

[0071] Figure 5 The image shows the effect of using the method for automatically constructing lane centerlines in this application. Detailed Implementation

[0072] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0073] This invention provides a method for automatically constructing lane centerlines, such as... Figure 1 and Figure 2 As shown, it includes:

[0074] Step S1: Obtain the road surface data and intersection surface data of the lane to be constructed, and divide them into lane lines and road trajectories;

[0075] In one embodiment, the road surface data and intersection surface data include lane lines, vehicle travel trajectories, road directional arrows, guardrails, curbs, and green belts, etc.

[0076] Step S2: Based on the lane lines and road trajectory, adjust the direction of the lane lines to make them consistent with the direction of the road trajectory, dividing them into two lane lines.

[0077] Step S3: Based on the direction of the adjusted lane lines, divide the road into two separate directional roads;

[0078] Step S4: Based on the roads in different directions, generate break lines according to the locations of road changes and breaks, and in conjunction with road trend lines;

[0079] In one embodiment, generating the break line specifically includes:

[0080] Step S4.1: Using the road trend line and lane line endpoints, draw a perpendicular line from the trend line direction at the endpoints;

[0081] Step S4.2: Cluster the vertical lines according to the distance between the lane lines and merge them into a single break line;

[0082] Step S4.3: Sort the broken lines according to the direction of the road trend line;

[0083] Step S4.4: Divide the road into segments according to the order of the pre-sorted break lines;

[0084] Step S4.5: Arrange the lane lines in the road segment in order from top to bottom;

[0085] Step S4.6: Iterate through the two adjacent lane lines from top to bottom, determine the trend of the distance change between the upper lane line and the lower lane line, extract the coordinates of the inflection point of the change, and add a new break line according to the coordinate position.

[0086] Step S4.7: Combine the new break line and the old break line, and repeat steps S4.1 to S4.3.

[0087] In this embodiment, by combining road trend lines at road changes to generate break lines, even if there are changes in road height, the road trend lines are fully considered and break lines are generated through clustering, which improves the accuracy of break lines and allows for more accurate construction of lane center lines.

[0088] like Figure 4As shown, at overpasses or multi-level bridges, break lines are generated by combining road trend lines, making the constructed lane center lines more accurate and unaffected by changes in road trends.

[0089] Step S5: Divide the road into segments based on the lane lines and their corresponding break lines, and generate lane center lines in accordance with road rules.

[0090] In one embodiment, generating the lane centerline specifically includes:

[0091] Step S5.1: Using the break line and following steps S4.4 and S4.5, divide the road and lane lines into sorted road segments and lane lines;

[0092] Step S5.2: Iterate through the two adjacent lane lines from top to bottom, determine whether the distance between the upper lane line and the lower lane line meets the width of the generated lane center line and whether it meets the ground feature constraints; for the two lane lines that meet the corresponding conditions, generate multiple center points in sequence according to the order of the points constituting the lane lines, and finally fit and generate the lane center line.

[0093] In this embodiment, the width of the center line is generally 2-8. m Between these, the constraints on features include those that conform to features such as flower beds and bus stops.

[0094] Furthermore, the generation of the lane centerline also includes:

[0095] By utilizing the front-to-back relationship between the road segments, and by determining whether the lane center lines between adjacent front-to-back road segments are generated by the same or two lane lines, the corresponding front-to-back endpoints of the two lane center lines are adjusted to ensure the upstream and downstream connectivity of the lane center lines.

[0096] When there are non-connected center lines between adjacent lane center lines, it is necessary to determine the connection relationship between the adjacent lane center lines and whether the current lane center line can connect to the connection point of the adjacent lane center lines. If the relevant conditions, such as not crossing solid lines or hitting curbs, are met, then the connection can be made.

[0097] Step S6: At the intersection, generate the intersection lane center lines by combining the relationship between the lane center lines and directional arrows of the entrances and exits, as well as the road rules.

[0098] In one embodiment, generating the center line of the intersection lanes specifically includes:

[0099] Step S6.1: Using the intersection data and the lane centerline, determine the centerline of the lane entering the intersection and the centerline of the lane exiting the intersection;

[0100] Step S6.2: Combining the intersection relationship between the directional arrow and the lane center line, add the actual left and right relationship of the lane to determine the turning relationship of the lane center line entering the intersection;

[0101] Step S6.3: Calculate the corresponding steering method based on the angle between the center line of the lane entering the intersection and the center line of the lane exiting the intersection, and then determine whether it is consistent with the steering relationship of the center line of the lane entering the intersection.

[0102] Step S6.4: Combining the relevant lines in the intersection, including lane lines, curb lines, and safety island boundaries, the front and rear endpoints of the relevant lines can cut off part of the intersection lane center line on both sides of the relevant lines;

[0103] The center lines of the lanes at the cut-off points converge to form a common center line, which then establishes a left-right relationship with the lane lines, curb lines, and safety island boundary lines that cut it off. At the same time, the upstream and downstream relationships of the cut-off lane center lines are adjusted.

[0104] The road rules in this embodiment include: the road width is on average more than 2.5 meters; lane changing is prohibited across solid lines; lane changing follows the nearest principle, and other traffic rules.

[0105] Furthermore, in step S6.3, it is determined whether the detection is consistent. If they are consistent, the center line connecting the center line of the lane entering the intersection and the center line of the lane exiting the intersection is calculated.

[0106] The calculation of the connection centerline uses Bézier curve fitting or catmull Fitting or intersection trajectory extraction.

[0107] The present invention also provides a system for automatically constructing lane centerlines, comprising:

[0108] Module M1: Acquires road surface data and intersection surface data of the lane to be constructed, and divides them into lane lines and road trajectories;

[0109] Module M2: Adjusts the direction of the lane lines based on the lane lines and road trajectory, dividing the lane lines into two directions to ensure they align with the direction of the road trajectory;

[0110] Module M3: Based on the direction of the adjusted lane lines, the road is divided into two separate directional roads;

[0111] Module M4: Based on the roads in the given directions, and according to the locations of road changes and breaks, and in conjunction with the road trend lines, generate break lines;

[0112] Module M5: Based on the lane lines and their corresponding break lines, divide the road into segments and generate lane center lines in accordance with road rules;

[0113] Module M6: At the intersection, it generates the intersection lane center lines by combining the relationship between the lane center lines and directional arrows of the entrances and exits, as well as the road rules.

[0114] Generating break lines specifically includes:

[0115] Module M4.1: Using the road trend line and lane line endpoints, draw a perpendicular line from the trend line direction at the endpoint;

[0116] Module M4.2: Based on the distance between lane lines, cluster the vertical lines and merge them into a single break line;

[0117] Module M4.3: Sort the break lines according to the direction of the road trend line;

[0118] Module M4.4: Divides the road into segments according to the order of the pre-sorted break lines;

[0119] Module M4.5: Sorts lane markings in a road segment in a top-to-bottom order;

[0120] Module M4.6: Iterate through two adjacent lane lines from top to bottom, determine the trend of distance change between the upper lane line and the lower lane line, extract the coordinates of the inflection point of the change, and add a new break line according to the coordinate position;

[0121] Module M4.7: Combines the new and old break lines, and re-executes modules M4.1 to M4.3.

[0122] Generating lane centerlines specifically includes:

[0123] Module M5.1: Using break lines and in accordance with Modules M4.4 and M4.5, the road and lane lines are divided into sorted road segments and lane lines;

[0124] Module M5.2: Iterates through two adjacent lane lines from top to bottom, determines whether the distance between the upper lane line and the lower lane line meets the width of the generated lane center line, and whether it meets the ground feature constraints; for two lane lines that meet the corresponding conditions, multiple center points are generated sequentially according to the order of the points constituting the lane lines, and finally the lane center line is generated by fitting.

[0125] Furthermore, generating the lane centerline also includes:

[0126] By utilizing the front-to-back relationship between the road segments, and by determining whether the lane center lines between adjacent front-to-back road segments are generated by the same or two lane lines, the corresponding front-to-back endpoints of the two lane center lines are adjusted to ensure the upstream and downstream connectivity of the lane center lines.

[0127] When there are non-connected center lines between adjacent lane center lines, it is necessary to determine the connection relationship between the adjacent lane center lines and whether the line can connect to the connection point of the adjacent lane center lines. If the relevant conditions, such as not crossing solid lines or hitting curbs, are met, then the connection can be made.

[0128] Generating the center line of the intersection lanes specifically includes:

[0129] Module M6.1: Utilizes the intersection relationship between intersection surface data and lane center lines to determine the center lines of lanes entering and exiting the intersection;

[0130] Module M6.2: Combines the intersection relationship between the directional arrow and the lane center line, adds the actual left and right relationship of the lane, and determines the turning relationship of the lane center line when entering the intersection;

[0131] Module M6.3: Calculates the corresponding steering method based on the angle between the center line of the lane entering the intersection and the center line of the lane exiting the intersection, and then determines whether it is consistent with the steering relationship of the center line of the lane entering the intersection.

[0132] Module M6.4: Combines relevant lines including lane lines, curb lines, and safety island boundaries in intersections, and the front and rear endpoints of the relevant lines can cut off part of the intersection lane center line on both sides of the relevant lines;

[0133] The center lines of the lanes at the cut-off points converge to form a common center line, which then establishes a left-right relationship with the lane lines, curb lines, and safety island boundary lines that cut it off. At the same time, the upstream and downstream relationships of the cut-off lane center lines are adjusted.

[0134] Furthermore, module M6.3 determines whether the detection is consistent. If it is consistent, it calculates the connecting center line of the lane center line entering the intersection and the lane center line exiting the intersection.

[0135] The centerline calculation uses Bézier curve fitting or catmull Fitting or intersection trajectory extraction.

[0136] Those skilled in the art will understand that, besides implementing the system and its various devices, modules, and units provided by this invention in the form of purely computer-readable program code, the same functions can be achieved entirely through logical programming of the method steps, making the system and its various devices, modules, and units of this invention function in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers. Therefore, the system and its various devices, modules, and units provided by this invention can be considered as a hardware component, and the devices, modules, and units included therein for implementing various functions can also be considered as structures within the hardware component; alternatively, the devices, modules, and units for implementing various functions can be considered as both software modules implementing the method and structures within the hardware component.

[0137] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for automatically constructing lane centerlines, characterized in that, include: Step S1: Obtain the road surface data and intersection surface data of the lane to be constructed, and divide them into lane lines and road trajectories; Step S2: Based on the lane lines and road trajectory, adjust the direction of the lane lines to make them consistent with the direction of the road trajectory, dividing them into two lane lines. Step S3: Based on the direction of the adjusted lane lines, divide the road into two separate directional roads; Step S4: Based on the roads in different directions, generate break lines according to the locations of road changes and breaks, and in conjunction with road trend lines; Step S5: Divide the road into segments based on the lane lines and their corresponding break lines, and generate lane center lines in accordance with road rules; Step S6: At the intersection, based on the relationship between the lane center lines and directional arrows of the entrances and exits, as well as the road rules, generate the lane center lines for the intersection. The generation of the break line specifically includes: Step S4.1: Using the road trend line and lane line endpoints, draw a perpendicular line from the trend line direction at the endpoints; Step S4.2: Cluster the vertical lines according to the distance between the lane lines and merge them into a single break line; Step S4.3: Sort the broken lines according to the direction of the road trend line; Step S4.4: Divide the road into segments according to the order of the pre-sorted break lines; Step S4.5: Arrange the lane lines in the road segment in order from top to bottom; Step S4.6: Iterate through the two adjacent lane lines from top to bottom, determine the trend of the distance change between the upper lane line and the lower lane line, extract the coordinates of the inflection point of the change, and add a new break line according to the coordinate position. Step S4.7: Combining the new break line and the old break line, repeat steps S4.1 to S4.3; The generated lane centerline specifically includes: Step S5.1: Using the break line and following steps S4.4 and S4.5, divide the road and lane lines into sorted road segments and lane lines; Step S5.2: Iterate through the two adjacent lane lines from top to bottom, determine whether the distance between the upper lane line and the lower lane line meets the width of the generated lane center line and whether it meets the ground feature constraints; for the two lane lines that meet the corresponding conditions, generate multiple center points in sequence according to the order of the points constituting the lane lines, and finally fit and generate the lane center line.

2. The method for automatically constructing lane centerlines according to claim 1, characterized in that, The generated lane centerline also includes: By utilizing the front-to-back relationship between the road segments, and by determining whether the lane center lines between adjacent front-to-back road segments are generated by the same or two lane lines, the corresponding front-to-back endpoints of the two lane center lines are adjusted to ensure the upstream and downstream connectivity of the lane center lines. When there are non-connected center lines between adjacent lane center lines, it is necessary to determine the connection relationship between the adjacent lane center lines and whether the current lane center line can connect to the connection point of the adjacent lane center lines. If the relevant conditions, such as not crossing solid lines or hitting curbs, are met, then the connection can be made.

3. The method for automatically constructing lane centerlines according to claim 1, characterized in that, The generation of the intersection lane centerline specifically includes: Step S6.1: Using the intersection data and the lane centerline, determine the centerline of the lane entering the intersection and the centerline of the lane exiting the intersection; Step S6.2: Combining the intersection relationship between the directional arrow and the lane center line, add the actual left and right relationship of the lane to determine the turning relationship of the lane center line entering the intersection; Step S6.3: Calculate the corresponding steering method based on the angle between the center line of the lane entering the intersection and the center line of the lane exiting the intersection, and then determine whether it is consistent with the steering relationship of the center line of the lane entering the intersection. Step S6.4: Combining the relevant lines in the intersection, including lane lines, curb lines, and safety island boundaries, the front and rear endpoints of the relevant lines can cut off part of the intersection lane center line on both sides of the relevant lines; The center lines of the lanes at the cut-off points converge to form a common center line, which then establishes a left-right relationship with the lane lines, curb lines, and safety island boundary lines that cut it off. At the same time, the upstream and downstream relationships of the cut-off lane center lines are adjusted.

4. The method for automatically constructing lane centerlines according to claim 3, characterized in that, In step S6.3, it is determined whether the detection is consistent. If it is consistent, the center line connecting the center line of the lane entering the intersection and the center line of the lane exiting the intersection is calculated. The calculation of the connection centerline uses Bézier curve fitting or catmull Fitting or intersection trajectory extraction.

5. A system for automatically constructing lane centerlines, characterized in that, include: Module M1: Acquires road surface data and intersection surface data of the lane to be constructed, and divides them into lane lines and road trajectories; Module M2: Adjusts the direction of the lane lines based on the lane lines and road trajectory, dividing the lane lines into two directions to ensure they align with the direction of the road trajectory; Module M3: Based on the direction of the adjusted lane lines, the road is divided into two separate directional roads; Module M4: Based on the roads in the given directions, and according to the locations of road changes and breaks, and in conjunction with the road trend lines, generate break lines; Module M5: Based on the lane lines and their corresponding break lines, divide the road into segments and generate lane center lines in accordance with road rules; Module M6: At the intersection, the lane center lines are generated by combining the relationship between the lane center lines and directional arrows at the entrances and exits, as well as the road rules. The generation of the break line specifically includes: Module M4.1: Using the road trend line and lane line endpoints, draw a perpendicular line from the trend line direction at the endpoint; Module M4.2: Based on the distance between lane lines, cluster the vertical lines and merge them into a single break line; Module M4.3: Sort the break lines according to the direction of the road trend line; Module M4.4: Divides the road into segments according to the order of the pre-sorted break lines; Module M4.5: Sorts lane markings in a road segment in a top-to-bottom order; Module M4.6: Iterate through two adjacent lane lines from top to bottom, determine the trend of distance change between the upper lane line and the lower lane line, extract the coordinates of the inflection point of the change, and add a new break line according to the coordinate position; Module M4.7: Combines the new and old break lines, and re-executes modules M4.1 to M4.3; The generated lane centerline specifically includes: Module M5.1: Using break lines and in accordance with Modules M4.4 and M4.5, the road and lane lines are divided into sorted road segments and lane lines; Module M5.2: Iterates through two adjacent lane lines from top to bottom, determines whether the distance between the upper lane line and the lower lane line meets the width of the generated lane center line, and whether it meets the ground feature constraints; for two lane lines that meet the corresponding conditions, multiple center points are generated sequentially according to the order of the points constituting the lane lines, and finally the lane center line is generated by fitting.

6. The system for automatically constructing lane centerlines according to claim 5, characterized in that, The generated lane centerline also includes: By utilizing the front-to-back relationship between the road segments, and by determining whether the lane center lines between adjacent front-to-back road segments are generated by the same or two lane lines, the corresponding front-to-back endpoints of the two lane center lines are adjusted to ensure the upstream and downstream connectivity of the lane center lines. When there are non-connected center lines between adjacent lane center lines, it is necessary to determine the connection relationship between the adjacent lane center lines and whether the line can connect to the connection point of the adjacent lane center lines. If the relevant conditions, such as not crossing solid lines or hitting curbs, are met, then the connection can be made.

7. The system for automatically constructing lane centerlines according to claim 5, characterized in that, The generation of the intersection lane centerline specifically includes: Module M6.1: Utilizes the intersection relationship between intersection surface data and lane center lines to determine the center lines of lanes entering and exiting the intersection; Module M6.2: Combines the intersection relationship between the directional arrow and the lane center line, adds the actual left and right relationship of the lane, and determines the turning relationship of the lane center line when entering the intersection; Module M6.3: Calculates the corresponding steering method based on the angle between the center line of the lane entering the intersection and the center line of the lane exiting the intersection, and then determines whether it is consistent with the steering relationship of the center line of the lane entering the intersection. Module M6.4: Combines relevant lines including lane lines, curb lines, and safety island boundaries in intersections, and the front and rear endpoints of the relevant lines can cut off part of the intersection lane center line on both sides of the relevant lines; The center lines of the lanes at the cut-off points converge to form a common center line, which then establishes a left-right relationship with the lane lines, curb lines, and safety island boundary lines that cut it off. At the same time, the upstream and downstream relationships of the cut-off lane center lines are adjusted.

8. The system for automatically constructing lane centerlines according to claim 7, characterized in that, In module M6.3, it is determined whether the detection is consistent. If they are consistent, the center line connecting the center line of the lane entering the intersection and the center line of the lane exiting the intersection is calculated. The calculation of the connection centerline uses Bézier curve fitting or catmull Fitting or intersection trajectory extraction.

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