High-precision road surface format conversion fitting method and system for Shp to OpenDRIVE

Abstract

The invention discloses a high-precision road surface format conversion fitting method and a high-precision road surface format conversion fitting system from Shp to OpenDRIVE. According to the method, a unified course angle is constructed based on road topology, ParamPoly3 fitting is performed on tangential, transverse and elevation components by adopting arc length parameterization and a local orthogonal basis, and position and tangential boundary constraints are applied to starting and ending ends to ensure continuous and transverse strict orthogonality; in the bifurcation / convergence topology, endpoint offset is carried out in the normal direction according to the cumulative lane width according to the main road endpoint course, and smooth adjustment of end-to-end linear interpolation is carried out on a center line; single front / back matching with shared nodes is adopted on a lane link to ensure physical consistency. And finally, outputting a reference line, a lane and a link structure which conform to OpenDRIVE. Compared with an existing process, the method does not need a large amount of manual correction, can keep tangential continuity, strict transverse orthogonality and overall geometric smoothness at the joint, remarkably improves the conversion efficiency, precision and robustness, and is suitable for engineering production of a complex lane network.

Description

Technical Field

[0001] This invention relates to high-precision map road geometry automatic generation technology, specifically to a high-precision road surface format conversion and fitting method and system for Shp to OpenDRIVE. Background Technology

[0002] With the rapid development of intelligent transportation, digital twins, and driving simulation, standardized static road network data has become a key infrastructure supporting algorithm verification and virtual testing. ASAM OpenDRIVE provides a unified description of road geometry, lane systems, and intersection topology for simulation and testing scenarios, enabling road networks to be exchangeable, computable, and reusable within a unified coordinate framework. Meanwhile, a large amount of existing road data in the industry is stored in GIS vectors (such as Shapefiles), possessing a complete system of elements and attributes and facilitating production maintenance. To reuse existing data resources in the simulation pipeline, it is urgent to establish a bridge from GIS semantics to OpenDRIVE parametric road networks, achieving accurate mapping of road reference lines, lanes, and topological relationships, and meeting the consistent data requirements of different platforms and toolchains.

[0003] With the increasing demand for standardized road network data in simulation and autonomous driving testing, the core task is to accurately convert commonly used GIS vector data (such as Shapefiles) into the ASAM OpenDRIVE (Xodr) standard. Shapefiles organize road centerlines, boundaries, and semantics using feature geometry and attribute tables; OpenDRIVE, on the other hand, expresses road orientation using reference line s / t / h coordinate systems, geometric segments, and parametric cubic polynomials (paramPoly3), and organizes lanes and topology in structures such as lanes, elevationProfile, superelevation, link, and junction. The two have different representation paradigms, and the key to the conversion lies in semantic mapping and parameterization: converting centerline features into reference lines and establishing s-axis arc lengths, generating lateral t-positions based on lane width and offset, mapping elevation and superelevation to corresponding profiles, constructing successor relationships and intersection connections, and ensuring the geometric segments... The lane's lateral direction is orthogonal to the reference line. Therefore, an engineered automatic conversion process from shapefile (SHP) to OpenDRIVE is required: the reference line is fitted based on arc length parameterization and a local orthogonal basis; endpoint headings are unified and tangential directions are constrained; lanes and topology are generated according to the structure; and finally, an Xodr file that meets specifications and can be used for simulation and testing is output. Summary of the Invention

[0004] The object of the present invention is to provide a high-precision road surface format conversion fitting method and system for Shp to OpenDRIVE, so as to overcome the deficiencies in simulation accuracy and simulation type of the prior art.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A high-precision road surface format conversion fitting method for Shp to OpenDRIVE includes the following steps:

[0007] S1, based on the Shp road data, construct a unified heading angle and topological connection system;

[0008] S2, under the unified heading, perform ParamPoly3 fitting on the $u / v / z$ directions with arc length parameterization and local orthogonal basis, and apply $C^0 / C^1$ and endpoint weighting;

[0009] S3, perform endpoint normal offset and centerline smoothing at bifurcations / merging points according to the topology to generate OpenDRIVE parameterized geometry.

[0010] Preferably, the unified heading angle system is constructed by vector averaging the start and end headings of the roads entering and leaving the same node to reduce the deviation caused by angle periodicity; if the node lacks a unified slope, the heading of the end point of the previous road and the heading of the start point of the subsequent road are used as the fallback constraints for the start and end ends respectively.

[0011] Preferably, the normalized parameters of the weighted least squares satisfy and , and the derivative conversion relationship is , and the boundary accuracy of the fitting result is improved by endpoint weighting.

[0012] Preferably, construct formulas for position and tangential boundary constraints as follows:

[0013]

[0014] In the formula, are the local coordinate components along the tangential and transverse directions of the reference line respectively; are the tangential and transverse derivatives with respect to the arc length $s$ respectively; represents the arc length parameter along the reference line, represents the total arc length of the current fitting segment, represent the reference line heading angles of the start and end points of the fitting segment respectively, represents the wrapping function that normalizes the angle difference to the interval.

[0015] Preferably, formulas can be constructed for the orthogonal constraint in the lateral direction of the lane as follows:

[0016]

[0017] In the formula, Represents the arc length along the reference line The lateral unit direction vector of the lane at that location; These represent the tangent vector, principal normal vector, and binormal vector of the reference line at that point, respectively. The rotation angle of the lane's lateral direction relative to the principal normal vector.

[0018] Preferably, the endpoint offset logic of the bifurcation / merging topology can be constructed as follows:

[0019]

[0020] In the formula, Main road endpoint heading The normal unit vector at that location; Accumulate lane width at the node; Left and right side labels; These are the target start and end points, respectively. These are the corrected start and end points of the sub-roads.

[0021] Preferably, the centerline smoothing adjustment uses end-to-end linear interpolation, and the displacement formula is as follows:

[0022]

[0023] In the formula, These are the endpoint displacements; Linear interpolation weights from the starting point to the ending point ( (Total number of points on the center line). $P_i$ and $P_i'$ are the centerline points before and after interpolation, respectively.

[0024] A high-precision road surface format conversion and fitting system for Shp to OpenDRIVE, characterized by comprising a core architecture module, an ensemble simulation module, a topology optimization module, and an output adaptation module:

[0025] The core architecture module realizes the core logic design of building a unified heading angle system and "parametric fitting + topology correction";

[0026] The geometric fitting module enables the establishment of local orthogonal bases, ParamPoly3 fitting, and weighted least squares solution.

[0027] The topology optimization module enables the application of boundary constraints, construction of orthogonal directions, offset of topology endpoints, and smooth adjustment of centerlines.

[0028] The output adapter module is used to convert optimized geometric data into the OpenDRIVE standard parametric format and output it.

[0029] Compared with the prior art, the present invention has the following beneficial technical effects:

[0030] This invention addresses simulation and testing scenarios by proposing an automated conversion method from Shapefile to OpenDRIVE: It uses arc length parameterization and local orthogonal basis as its core, combined with ParamPoly3 fitting and endpoint-weighted weighted least squares, to ensure that geometric segments satisfy... The system ensures continuous lanes with strict orthogonality in the lateral direction. By unifying node heading and tangential boundary constraints, applying endpoint normal offsets at bifurcation / merging points, and performing end-to-end linear smoothing, complex topologies are consistently and computably represented in Xodr. Compared to existing processes that rely on manual adjustments, this invention significantly improves conversion efficiency and consistency, supports stable generation of batch road data, and is highly compatible with the Xodr interface of mainstream simulation platforms. It also provides error management and piecewise refitting strategies to guarantee boundary accuracy, outputting structurally complete and semantically clear Xodr files for easy integration with subsequent elevation / superelevation and lanes / link / junction modules. Attached Figure Description

[0031] To more clearly illustrate the technical solution of the present invention, the accompanying drawings are briefly described below:

[0032] Figure 1 This is a schematic diagram of the high-precision road surface format conversion and fitting method for Shp to OpenDRIVE in an embodiment of the present invention.

[0033] Figure 2 This is a schematic diagram of a high-precision fitting correction scheme in an embodiment of the present invention.

[0034] Figure 3 This is a schematic diagram illustrating the problem of generating road surface overlap in an embodiment of the present invention.

[0035] Figure 4 This is a schematic diagram illustrating the problem of generating missing road surfaces in an embodiment of the present invention.

[0036] Figure 5 This is a schematic diagram of a special road correction scheme in an embodiment of the present invention.

[0037] Figure 6 This is a schematic diagram of a special road correction method in an embodiment of the present invention.

[0038] Figure 7 This is a schematic diagram of the original shp format data in an embodiment of the present invention.

[0039] Figure 8 This is a schematic diagram of Xodr rendering output data in an embodiment of the present invention.

[0040] Figure 9 This is a schematic diagram showing the comparison of data processing before and after road surface merging and branching intersections in an embodiment of the present invention.

[0041] Figure 10 This is a schematic diagram showing the comparison of data processing before and after processing of complex intersections in an embodiment of the present invention.

[0042] Figure 11 This is a schematic diagram showing the comparison of data processing before and after processing at a special intersection in an embodiment of the present invention. Detailed Implementation

[0043] like Figure 1 As shown, this invention provides a high-precision road surface format conversion and fitting method for Shp to OpenDRIVE, specifically including the following steps:

[0044] S1, based on Shp road data, constructs a unified heading angle and topology connection system;

[0045] S2, under a unified flight direction, parameterized by arc length and using a local orthogonal basis, for Direction execution ParamPoly3 fitting and application Weighting with endpoints;

[0046] S3, according to the topology, performs endpoint normal offset and centerline smoothing at bifurcation / merging points to generate OpenDRIVE parametric geometry.

[0047] In the specific implementation of this application, arc length parameterization and a ParamPoly3 (default cubic) polynomial model are used, and uniform slope / heading constraints are introduced at the endpoints to ensure connection continuity. To establish the geometric description of the road reference line, the reference line is assumed to be a three-dimensional curve. ,in For arc length parameters, Define the Frenet frame. , Its evolution satisfies

[0048]

[0049] in For curvature, Let be the torsion rate. For arc length parameters; It is a space curve; These are the tangential, normal, and binormal unit vectors, respectively; the left-falling stroke indicates the direction of the vector. The derivative; (When considering arc length parameters); To perform numerical fitting, the arc length of the sampling points is first parameterized as follows. The sampling points are denoted as... :

[0050]

[0051] in, For the first One sampling point; From the starting point to The cumulative arc length; This is the total arc length; These are normalized parameters (used for numerical fitting and interpolation). Subsequently, a uniform heading constraint is applied at the connection, with the start and end headings given by the heading angles of nodes S / E:

[0052]

[0053] And define the relative destination heading ,in Normalize the angle difference to Interval. These are the starting and ending heading angles, respectively. Return vector The polar angle; Standardize the angle to ; Let be the component of the tangential projection onto the plane. Construct a local orthogonal basis at the starting point of the reference line:

[0054]

[0055] in, This forms an orthogonal local basis at the starting point; Axis along the tangential direction (heading); Axis along the normal (lateral direction); The axis is along the secondary normal (vertical / superelevation direction). On this base, the components along the tangential, lateral, and elevation directions are represented by ParamPoly3 (default cubic):

[0056]

[0057] When using normalization parameters season The coefficients are scaled accordingly. Among them, The three-dimensional coordinate components on the local basis (corresponding to respectively) ); The coefficients are those of a cubic polynomial; when... When parameterizing, the coefficients need to be... Scale transformations are performed to maintain consistency of physical quantities. This is combined with the road surface superelevation (cross slope) angle. With lateral offset The three-dimensional coordinates of any point on the road surface are written as:

[0058]

[0059] If only the reference line center is fitted (excluding lane offset), then... .in, These are the three-dimensional coordinates of a point on the road surface. Lateral offset of the lane; For superelevation (cross slope) angle, control The rotation of the plane; the three terms represent tangential advancement, local lateral and elevation offsets, and the lane's lateral position under superelevation, respectively. To ensure continuity of position and tangential direction. Apply the following boundary conditions to the endpoints:

[0060]

[0061] The tangential direction is constrained by the consistency of local derivatives at the endpoints:

[0062]

[0063] Where $ In This holds true when parameterized. The position constraint of the endpoint in the local system; For the tangential and transverse derivatives; The destination is relative to the course; the chain rule gives the following... The relationship between the derivative during parameterization and the physical length. Under the above constraints, the polynomial coefficients are solved using weighted least squares consistent with endpoint weighting:

[0064]

[0065] in If the error exceeds the tolerance, refit at a lower order. These are weighting coefficients (larger endpoints to enhance boundary fitting); Represents linear constraints such as position / tangential direction. It is a vector consisting of all coefficients; The polynomial is set to the Euclidean norm. When the error exceeds the tolerance threshold, the polynomial order can be reduced or the fit can be re-pieceed. When the error exceeds the tolerance, piecewise fitting is used, and continuity is strictly satisfied at the segment boundaries; let the segmentation points be... , No. Segment fits on its own local basis And satisfy:

[0066]

[0067] And cumulative Offset: . For the first The segmental arc length position; The first The endpoints and tangential direction of the segment; Continuity ensures that there are no jumps in position or orientation between segments; This is used to output the cumulative offset of each segment in the geometry, serving as the starting point for OpenDRIVE.

[0068] In a specific embodiment of this application, by adjusting the tangential orientation angle of the reference lines of each lane surface at the connection point of the multi-lane surface, the orientation angle of the first and last segments of the reference lines of the lane surface is adjusted, thereby ensuring that the tangential orientation of the reference lines of each lane surface at the connection point is consistent, thus ensuring that the generated lane surface has no redundant overlapping parts.

[0069] To satisfy the orthogonal constraints and slope consistency at the connection points in OpenDRIVE, the lateral direction of the lane is first constructed and required to be orthogonal to the tangential direction of the reference line:

[0070]

[0071] in These are the reference lines with arc length parameters. The tangential / primary normal / secondary normal direction below. For the superelevation angle, this formula guarantees that the lateral direction is for any... Orthogonal to the tangential direction. Subsequently, a uniform heading constraint is applied at the connection, with the start and end headings given by the heading angles of nodes S / E:

[0072]

[0073] If the nodes do not have a uniform slope, a backoff strategy is adopted:

[0074]

[0075] In local base Apply boundary derivative constraints to lock the start and end directions:

[0076]

[0077] At the connection nodes, the multi-lane surface must strictly meet the cross-surface requirements. continuous:

[0078]

[0079] Location With tangential Continuously apply synchronously during piecewise fitting, accumulating Offset is used to specify the segment start point for output geometry: The unified heading is derived from the average slope of node aggregation. Local ParamPoly3 uses boundary derivative constraints to lock the start and end directions. Lateral headings are based on... By constructing an ultra-high angle structure to ensure orthogonality with the reference line tangent, and through these constraints, the road surface overlap and missingness caused by "lateral non-perpendicularity / inconsistent connection tangents" in the original shapefile are eliminated during the conversion stage. Its high-precision fitting correction scheme is as follows: Figure 2 As shown, it effectively solves the problem. Figure 3 , Figure 4 The problem of overlapping generated road surfaces is shown.

[0080] In the specific implementation of this application, for the special road surface misalignment adjustment of complex topologies such as bifurcation and merging, a correction process of "node target point and heading alignment - normal offset - end-to-end smooth interpolation" is adopted. For example... Figure 5 As shown, first select the target start and end points aligned with the main road at the node:

[0081]

[0082] in These are the target start and end points aligned with the main road at the nodes; if only a predecessor or successor exists, only the corresponding end is updated. Then, heading alignment is performed, and rotation is defined and applied locally.

[0083]

[0084]

[0085] in From the average heading of the connection Give, As the starting point and the next point, This is the penultimate point and the endpoint. Then, offset along the normal direction according to the cumulative total lane width:

[0086]

[0087] The above offset positions the endpoints of the sub-road reference lines to the correct lateral positions; the main road endpoints are used as alignment references.

[0088]

[0089] The starting point of the sub-road is aligned with the ending point of the main road (using...) The end point of the sub-road is aligned with the start point of the main road (using...). ), and along the corresponding normal direction By cumulative width Offset to the target position. Finally, perform end-to-end smooth position interpolation, with a special road correction scheme as follows: Figure 6 As shown:

[0090]

[0091]

[0092] in Under the displacement constraints at both ends, linear interpolation is used to make the entire centerline transition smoothly.

[0093] This application's method revolves around high-precision road geometry transformation from Shp to OpenDRIVE. It employs arc-length parameterization and ParamPoly3 fitting with a local orthogonal basis, combined with endpoint-weighted weighted least squares and position / tangential boundary constraints, to ensure the output geometry is continuous and smooth within segments and consistent with a unified heading. For connecting nodes, a node heading aggregation and backtracking strategy is used to ensure that adjacent lane surfaces are aligned in position. With tangential To maintain consistency, for complex topologies such as bifurcation and merging, based on target start and end point selection, local heading rotation alignment, normal offset according to cumulative width, and end-to-end linear interpolation, the physical and reasonable positioning of the reference line endpoints and the overall smooth transition are achieved, thereby eliminating road surface overlap and missing data caused by the original data. The comparison of data processing before and after the road surface merging bifurcation intersections and complex intersections is as follows: Figure 8 and Figure 9 As shown.

[0094] This method directly generates parametric geometry conforming to the OpenDRIVE specification, maintaining the orthogonality of the lane's lateral direction to the reference line tangent, and automatically segments to maintain global continuity when errors exceed limits. Validated on a real-world dataset, it stably completes the automated conversion from Shp to Xodr. The original Shp format data and the converted Xodr rendering output data are shown below. Figure 6 and Figure 7 As shown, this provides a consistent geometric basis for subsequent adaptation of OpenDRIVE to 3D models. Its special intersection data processing effect is as follows: Figure 10 As shown, the left image is the original Shp data, and the right image is the converted Xodr data.

[0095] To evaluate the conversion quality, a geometric error assessment method for road edges is established. Reference line point sequences are sampled at spatial resolution using OpenDRIVE's planView / geometry. The linear mapping between sampling points and mileage is

[0096]

[0097] The unit vector of the reference line tangent and the unit vectors of the left and right normals are defined as follows:

[0098]

[0099]

[0100] For a given mileage Choose to satisfy The last width entry is the applicable entry, let The lane width is given by a piecewise cubic polynomial.

[0101]

[0102] Using the reference line as the centerline boundary $\text{boundary}[0]$, the edge lines of the left and right lanes are recursively derived as follows:

[0103]

[0104]

[0105] If the Xodr header provides coordinate offsets Then apply to all edge sampling points

[0106]

[0107] Merge all line features in the Shhp into a line set. For each edge sampling point Calculated to shortest distance

[0108]

[0109] And based on distance samples Output statistical indicators

[0110]

[0111] in The average error, The median error is used. The evaluation test method directly focuses on "roadside lines," which is closer to the engineering concerns of road scope and boundaries. It strictly follows the OpenDRIVE reference lines and lane width definitions, and can more realistically reflect the quality of data conversion.

[0112] In our specific tests, we used real road surface image files (shp files) for format conversion and comparison. Figure 6 , Figure 7The accuracy information for the two formats, with a sample size of 11,716, shows that the average error after conversion is 0.0382m and the median error is 0.0102m. This indicates that the method used in this application can effectively process the conversion of various types of Shp file formats into Xodr data.

[0113] The technical solution of this invention is applicable to road scenarios with multi-lane networks, complex nodes, and elevation changes, and supports flexible configuration of different weight strategies and segmentation criteria. Without changing the overall principle, the relevant parameters and implementation details can be adjusted according to different data characteristics, all of which are within the protection scope of this invention.

[0114] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-precision road surface format conversion fitting method for Shp to OpenDRIVE, characterized in that, Includes the following steps: S1, based on Shp road data, constructs a unified heading angle and topology connection system; S2, under a unified flight direction, parameterized by arc length and using a local orthogonal basis, for Direction execution ParamPoly3 fitting and application Weighting with endpoints; S3, according to the topology, performs endpoint normal offset and centerline smoothing at bifurcation / merging points to generate OpenDRIVE parametric geometry.

2. The high-precision road surface format conversion and fitting method for Shp to OpenDRIVE according to claim 1, characterized in that, In step S1, the unified heading angle system is constructed by vector averaging of the starting and ending headings of roads entering and leaving the same node to reduce the deviation caused by the periodicity of the angle; if the node lacks a unified slope, the headings of the previous road end point and the headings of the subsequent road start point are used as backtracking constraints for the starting and ending points respectively; and it is coordinated with the parameterized fitting and topology correction process to realize the unified heading angle and its topology connection system.

3. The high-precision road surface format conversion and fitting method for Shp to OpenDRIVE according to claim 1, characterized in that, In step S2, under a unified heading and parameterized with a local orthogonal basis and arc length, the tangential direction is... Horizontal With elevation ParamPoly3 fitting was performed separately; the normalized parameters of the weighted least squares method satisfied... and The derivative transformation relationship is as follows: The boundary accuracy of the fitting results is improved by weighting the endpoints; when the error exceeds the limit, the order is reduced or piecewise refitting is used.

4. The high-precision road surface format conversion and fitting method for Shp to OpenDRIVE according to claim 3, characterized in that, Constructing formulas to ensure position and tangential boundary constraints Continuous, as shown below: In the formula, , These are the local coordinate components along the tangential and transverse directions of the reference line, respectively. , Relative to arc length Tangential and transverse derivatives; This represents the arc length parameter along the reference line. This represents the total arc length of the currently fitted segment. The reference line heading angles represent the start and end points of the fitted segment, respectively. The representative normalizes the angle difference to The wrapping function of an interval. Furthermore, positional and tangential boundary constraints are applied to the fitting results, and piecewise refitting is performed when the error exceeds the limit, while ensuring... continuous.

5. A high-precision road surface format conversion and fitting method for Shp to OpenDRIVE according to claim 3, characterized in that, A formula can be constructed to apply orthogonal constraints to the lateral direction of the lanes, thereby constructing lateral directions of the lanes that satisfy the orthogonal condition, as shown below: In the formula, Represents the arc length along the reference line The lateral unit direction vector of the lane at that location; These represent the tangent vector, principal normal vector, and binormal vector of the reference line at that point, respectively. The rotation angle of the lane's lateral direction relative to the principal normal vector.

6. The high-precision road surface format conversion and fitting method for Shp to OpenDRIVE according to claim 1, characterized in that, In step S3, the endpoint offset logic of the bifurcation / merging topology can be constructed into a formula to implement the topology correction logic, which is used for topology correction of the endpoint offset of the bifurcation / merging topology, as shown below: In the formula, Main road endpoint heading The normal unit vector at that location; Accumulate lane width at the node; Left and right side labels; These are the target start and end points, respectively. These are the corrected start and end points of the sub-roads.

7. A high-precision road surface format conversion and fitting method for Shp to OpenDRIVE according to claim 6, characterized in that, The centerline smoothing adjustment uses end-to-end linear interpolation, and the displacement formula is shown below: In the formula, These are the endpoint displacements; Linear interpolation weights from the starting point to the ending point ( (Total number of points on the center line). and These represent the centerline points before and after interpolation.

8. A high-precision road surface format conversion and fitting system for Shp to OpenDRIVE, characterized in that, It includes a core architecture module, an ensemble simulation module, a topology optimization module, and an output adaptation module. The core architecture module is used to implement the core logic design of the unified heading angle system construction and "parametric fitting + topology correction" described in step S1 of claim 1; The geometric fitting module is used to perform the local orthogonal basis establishment, ParamPoly3 fitting and weighted least squares solution as described in step S2 of claim 1. The topology optimization module is used to perform the boundary constraint application, orthogonal direction construction, topology endpoint offset and centerline smoothing adjustment as described in step S3 of claim 1; The output adapter module is used to convert the optimized geometric data into the OpenDRIVE standard parametric format and output it to generate OpenDRIVE parametric geometry.

9. A computer program product, characterized in that, When the computer program product is executed by a processor, it implements the steps of the generation method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The storage medium stores a computer program that, when executed by a processor, implements the steps of the generation method according to any one of claims 1 to 7.

Images