CN111047682B - A method and system for generating a three-dimensional lane model - Google Patents

Abstract

The invention relates to the technical field of three-dimensional road modeling, in particular to a three-dimensional lane model generation method and system, wherein a lane layer is firstly converted into a projection coordinate system from a longitude and latitude coordinate system; generating a central line and an edge line of a lane under a projection coordinate system; dividing the lane into a plurality of continuous triangular patches, and constructing two-dimensional coordinates of each triangular patch; constructing three-dimensional coordinates of each triangular patch by taking DEM data of the lane as a height value of each triangular patch; the invention can fully utilize the existing two-dimensional electronic map data to automatically construct the three-dimensional model of the lane, thereby saving a large amount of acquisition work and supporting the requirements of microscopic traffic simulation.

Description

A three-dimensional lane model generation method and system

Technical Field

The present invention relates to the technical field of three-dimensional road modeling, and in particular to a three-dimensional lane model generation method and system.

Background Art

The three-dimensional traffic network model and system is an important technology in the path navigation system and the intelligent traffic integrated command and dispatch system. For complex intersections and multi-layer interchanges, a three-dimensional road network is needed to clearly express the spatial connection relationship of the road, so that the road network analysis and calculation can be realized. At present, the general practice is to use three-dimensional modeling software (for example: 3DMax, Maya, etc.) to model and apply according to the geometric dimensions of the road. The disadvantage of this approach is that the workload is large. In the prior art, there are also methods for automatically constructing three-dimensional road network models, but these methods all use road sections as the minimum modeling unit, which cannot describe the topological relationship between lanes, and it is difficult to meet the needs of road network spatial analysis, so it is difficult to support refined micro-traffic simulation applications.

Only by building a detailed three-dimensional lane model and generating basic topological connection data can the needs of microscopic traffic simulation be supported. Therefore, the existing three-dimensional lane network model needs to be improved urgently.

Summary of the invention

The present invention provides a three-dimensional lane model generation method and system to solve one or more technical problems existing in the prior art and at least provide a beneficial choice or create conditions.

In order to achieve the above object, the present invention provides the following technical solutions:

A method for generating a three-dimensional lane model according to an embodiment of a first aspect of the present invention includes:

Convert the lane layer from the latitude and longitude coordinate system to the projection coordinate system;

Generate the center line and edge line of the lane in the projected coordinate system;

Divide the lane into multiple continuous triangular patches and construct the two-dimensional coordinates of each triangular patch;

The lane DEM data is used as the height value of each triangular face to construct the three-dimensional coordinates of each triangular face;

Connect the triangular patches in sequence to obtain a three-dimensional lane model.

Further, the generating of the center line and edge line of the lane in the projection coordinate system includes:

Obtaining the lane coordinates in the projection coordinate system, finding the middle value of the lane coordinates, and using the middle value as the centerline coordinates of the lane;

According to the number and width of lanes, the buffer distance of lanes is obtained;

Taking the center line of the lane as a reference, the center line of the lane is offset to both sides according to the buffer distance of the lane to obtain the edge lines of the two lanes.

Furthermore, the lane is divided into a plurality of continuous triangular facets and the two-dimensional coordinates of each triangular facet are constructed, including:

The center line and the edge line of the lane are divided into multiple continuous straight line segments, and the connection point of two adjacent straight line segments is taken as the vertex;

Generate two triangular facets from two opposite straight line segments, and connect the vertices of each triangular facet in a counterclockwise direction, so as to divide the lane into multiple connected triangular facets;

Construct the two-dimensional coordinates of each triangle according to the two-dimensional coordinates of each vertex.

Furthermore, the lane DEM data is used as the height value of each triangular facet to construct the three-dimensional coordinates of each triangular facet, including:

The DEM data of the vertex in the triangular patch is used as the height value of the vertex, so as to obtain the three-dimensional coordinates of the vertex in each triangular patch;

Calculate the ordinate of the center line according to the three-dimensional coordinates of the vertices in each triangular face;

The vertical coordinate of the center line is used as the height value of the lane, and the height value of the lane is combined with the two-dimensional coordinate of the triangular patch to obtain the three-dimensional coordinate of the triangular patch.

Further, the calculating the ordinate of the center line according to the three-dimensional coordinates of the vertices in each triangular facet includes:

Set the three-dimensional coordinates of any control point on the center line, obtain the two-dimensional coordinates of the control point, and determine the equation of the straight line passing through the control point and perpendicular to the XOY plane;

Establish the plane equation of the triangle according to the three vertices of the triangle;

Obtaining the ordinate of the control point according to the straight line equation and the plane equation;

The ordinate of the center line is obtained based on the ordinates of all control points on the center line.

Furthermore, before using the longitudinal coordinate of the center line as the height value of the lane, the method includes:

Determine whether the control point is inside the triangular patch, and if so, use the ordinate of the control point as the height value of the lane where the control point is located;

Make sure that all control points on the center line are inside the corresponding triangles.

Furthermore, the three-dimensional lane model is obtained by sequentially connecting the triangular facets, including:

Calculate the UV coordinates corresponding to each control point, perform continuous mapping on each triangle patch, and output a three-dimensional lane model.

A three-dimensional lane model generation system according to an embodiment of a second aspect of the present invention includes:

at least one processor;

at least one memory for storing at least one program;

When the at least one program is executed by the at least one processor, the at least one processor implements the three-dimensional lane model generation method described in the first aspect embodiment.

The beneficial effects of the present invention are as follows: the present invention discloses a method and system for generating a three-dimensional lane model, firstly converting the lane layer from a latitude and longitude coordinate system into a projection coordinate system; and generating the center line and edge line of the lane in the projection coordinate system; then dividing the lane into a plurality of continuous triangular facets, constructing the two-dimensional coordinates of each triangular facet; constructing the three-dimensional coordinates of each triangular facet by using the DEM data of the lane as the height value of each triangular facet; and thus connecting the triangular facets in sequence to obtain a three-dimensional lane model. The present invention can make full use of the existing two-dimensional electronic map data, automatically construct a three-dimensional model of the lane, can save a lot of collection work, and can support the needs of microscopic traffic simulation.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

FIG1 is a schematic diagram of a flow chart of a method for generating a three-dimensional lane model according to an embodiment of the present invention;

FIG2 is a schematic diagram of the process of step S200 in the embodiment of FIG1 ;

FIG3 is a schematic diagram showing the effect of step S200 in the embodiment of FIG1 ;

FIG4 is a schematic diagram showing the effect of step S300 in the embodiment of FIG1 ;

FIG. 5 is a schematic diagram showing the effect of step S400 in the embodiment of FIG. 1 .

DETAILED DESCRIPTION

The following will be combined with the embodiments and drawings to clearly and completely describe the concept, specific structure and technical effects of the present disclosure, so as to fully understand the purpose, scheme and effect of the present disclosure. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

Referring to FIG. 1 , a method for generating a three-dimensional lane model is shown in FIG. 1 , comprising the following steps:

Step S100: convert the lane layer from the latitude and longitude coordinate system to the projection coordinate system.

This step can be processed using tools such as ArcGIS or ArcMap. The conversion from the latitude and longitude coordinate system to the projection coordinate system is to facilitate subsequent calculations in the projection coordinate system. The coordinate conversion should be based on the region where the road is located, using a local coordinate system to ensure the accuracy of the coordinate conversion. In this embodiment, the ground is taken as the XOY plane, and the height direction of the road is the Z axis.

Step S200: Generate the center line and edge line of the lane in the projection coordinate system.

The center line and edge line are broken lines composed of a series of points, and the center line and edge line are represented by respective vertex coordinate point sets.

Step S300: Divide the lane into a plurality of continuous triangular facets, and construct the two-dimensional coordinates of each triangular facet.

Step S400: Use the DEM data of the lane as the height value of each triangular facet to construct the three-dimensional coordinates of each triangular facet.

Step S500: connect the triangular facets in sequence to obtain a three-dimensional lane model.

Lanes are the basic carriers for vehicle travel. A road section is composed of several lanes connected together. In this embodiment, the lane layer can be obtained using existing electronic map data, without the need for manual map data collection. This solution uses lanes with smaller granularity as the basic generation unit. Having a smaller object granularity will make the three-dimensional road network more refined and will also support more sophisticated business application functions (such as micro-traffic simulation); this solution uses a mathematical processing algorithm based on spatial analytic geometry to construct the three-dimensional coordinates of each triangular facet, so that the direction and slope of the lane are consistent with the terrain. This solution can make full use of the existing two-dimensional electronic map data, and automatically construct a three-dimensional model of the lane according to the constraint rules of the lane design and combined with the terrain data. This allows the three-dimensional road network data to support the needs of micro-traffic simulation.

Referring to FIG. 2 and FIG. 3 , in a preferred embodiment, step S200 includes:

Step S210: Obtain the lane coordinates in the projection coordinate system, find the middle value of the lane coordinates, and use the middle value as the centerline coordinates of the lane.

In this step, continuous lane coordinates are used to generate continuous intermediate values, which are center point coordinates. Continuous center point coordinates form center line coordinates. Since the coordinate values of the projection coordinate system are large, the intermediate values are obtained based on the obtained coordinates, and the intermediate values are used as the translation amount, that is, line buffering is performed on both sides, and the buffer distances are D1 and D2 respectively, to obtain the coordinates of the center line of the road after translation. Since the center line of the road is a polyline composed of a series of points, the buffer calculation is performed on each polyline, and then the intersection of two adjacent polylines is obtained.

Step S220, obtaining a lane buffer distance according to the number and width of the lanes;

Since the lane width is set according to the standard, after the number of lanes is determined, all straight line segments can be horizontally shifted at a fixed distance.

Step S230: Taking the center line of the lane as a reference, the center line of the lane is offset to both sides according to the buffer distance of the lane to obtain edge lines of two lanes.

The road centerline can be understood as a broken line composed of a series of points. After buffering calculation is performed on each broken line, the adjacent broken lines at both ends are connected to obtain the intersection of the two adjacent broken lines, thereby obtaining the offset edge line.

In a preferred embodiment, the step S300 is specifically as follows:

First, the center line and edge line of the lane are divided into multiple continuous straight line segments, and the connection point of two adjacent straight line segments is taken as the vertex;

Next, two triangular facets are generated from the two opposite straight line segments, and the vertices of each triangular facet are connected counterclockwise, thereby dividing the lane into multiple connected triangular facets;

Finally, the two-dimensional coordinates of each triangle are constructed according to the two-dimensional coordinates of each vertex. The two-dimensional coordinates are the coordinates of the lane projection on the horizontal plane.

As shown in Figure 4, the straight line segment sequence L1′, L2′, and L3′ that constitute the lane centerline, after buffer calculation, obtains lane edge line 1, whose straight line segment sequence is L1, L2, and L3, and obtains lane edge line 2, whose straight line segment sequence is L1″, L2″, and L3″; for the lane centerline, the intersection point v1 of the adjacent straight line segments L1′ and L2′, and the intersection point v4 of the straight line segments L2′ and L3′ can be obtained; the same algorithm can be used to obtain the intersection point v2 of the adjacent straight line segments L1″ and L2″, and the intersection point v3 of the straight line segments L2″ and L3″; among which the vertices v1 and v2, v4 and v3 have the same sequence numbers on the lane centerline, and in counterclockwise order, two groups of triangle patches (v1, v2, v4) and (v2, v3, v4) can be obtained.

In conjunction with FIG. 5 , in a preferred embodiment, step S400 includes:

First, the DEM data of the vertices in the triangular patch is used as the height value of the vertex to obtain the three-dimensional coordinates of the vertices in each triangular patch; then, the longitudinal coordinate of the center line is calculated according to the three-dimensional coordinates of the vertices in each triangular patch; the longitudinal coordinate of the center line is used as the height value of the lane, and the height value of the lane is combined with the two-dimensional coordinates of the triangular patch to obtain the three-dimensional coordinates of the triangular patch.

In a preferred embodiment, the step S420 includes:

(1) Set the three-dimensional coordinates of any control point on the center line and obtain the two-dimensional coordinates of the control point to determine the equation of the straight line passing through the control point and perpendicular to the XOY plane;

(2) Establish the plane equation of the triangle according to the three vertices of the triangle;

(3) obtaining the ordinate of the control point according to the straight line equation and the plane equation;

(4) The ordinate of the center line is obtained based on the ordinates of all control points on the center line.

In this embodiment, a vertical line is drawn to the ground for the centerline vertex. The equation of the vertical line can be obtained based on the vertex coordinates and the vertical vector. At the same time, the plane equation of each ground triangle patch can be calculated based on the vertex coordinates of the DEM data. The intersection of these two equations is found, and it is determined whether the point is inside the ground triangle patch. If it is inside the triangle, it is the projection point of the vertex on the terrain, that is, the actual lane centerline position coordinate. By traversing the lane centerline vertices and the terrain triangle patch, the height coordinates of all lane centerline vertices can be obtained.

The vertex coordinates X, Y, and Z components of the lane centerline have been obtained. By connecting all the triangle patch vertices counterclockwise, we can get the sequence of all the triangle patch vertices representing the lane road surface.

In this embodiment, the XY coordinates of each vertex, i.e., the coordinates of the road projected on the ground, have been obtained according to step S300. Since the road will also be ups and downs, its height is mainly affected by the terrain. Therefore, the DEM data of the terrain can be used as the reference data for calculating the height of the lane vertex.

In this embodiment, a vertical line is drawn from each lane centerline vertex to the ground. The equation of the vertical line can be obtained based on the vertex coordinates and the vertical vector. At the same time, the plane equation of each ground triangle patch can be calculated based on the vertex coordinates of the DEM data. The intersection of these two equations is found, and it is determined whether the point is inside the ground triangle patch. If it is inside the triangle, it is the projection point of the vertex on the terrain, that is, the actual lane centerline position coordinate. By traversing the lane centerline vertices and the terrain triangle patch, the height coordinates of all lane centerline vertices can be obtained.

After step S300 and step S400, the vertex coordinates X, Y, and Z component values of the lane centerline have been obtained, and all triangle facet vertex sequences representing the lane road surface can be obtained by organizing them counterclockwise.

In a preferred embodiment, before using the longitudinal coordinate of the center line as the height value of the lane, the method includes:

Determine whether the control point is inside the triangular patch. If so, use the ordinate of the control point as the height value of the lane where the control point is located; and determine that all control points on the center line are inside the corresponding triangular patch.

In this embodiment, a point in polygon algorithm is used to determine whether a control point is inside the triangle patch.

In a preferred embodiment, the step S500 is specifically as follows:

Calculate the UV coordinates corresponding to each control point, perform continuous mapping on each triangle patch, and output a three-dimensional lane model.

Specifically, after calculating the UV coordinates corresponding to each control point, each triangle face can be continuously mapped through OpenGL to finally obtain a complete three-dimensional lane model.

It can be seen from the description of one or more embodiments above that, compared with the prior art, the technical solution adopted by the present invention has the following advantages:

(1) 3D fine lane automatic generation technology:

The existing technology uses the road section as the smallest generation unit, while this solution uses the lane with a smaller granularity as the basic generation unit. Smaller object granularity will make the three-dimensional road network more refined and will also support more business application functions (such as micro traffic simulation).

(2) Make full use of existing electronic map data:

The existing technology has high requirements for the original data. In order to meet the goal of automatic generation, it is generally required to re-collect the data. This solution can use the existing electronic map data, and adopting this solution can save a lot of collection work.

(3) Fusion of terrain data:

The direction of the road is affected by the terrain. This solution uses a mathematical processing algorithm based on spatial analytic geometry to make the direction and slope of the lane consistent with the terrain.

With reference to FIG5 , in order to better illustrate the technical solution of the present invention, the present invention also provides the following specific embodiment for solving the problem.

For any control point V1 (a, b, c) on the lane centerline, the equation of the straight line passing through point V1 and perpendicular to the XOY plane is:

X＝a,Y＝b (1)

Assume that the coordinates of the three vertices of the terrain DEM data triangle are (x1, y1, z1), (x2, y2, z2), and (x3, y3, z3), then the plane equation of the triangle is:

Let the equation be:

A(x-x1)+B(y-y1)+C(z-z1)＝0; (3)

but:

A＝(y3-y1)*(z3-z1)-(z2-z1)*(y3-y1); (4)

B＝(x3-x1)*(z2-z1)-(x2-x1)*(z3-z1); (5)

C＝(x2-x1)*(y3-y1)-(x3-x1)*(y2-y1); (6)

Substituting equation (1) into equation (3), we can obtain the coordinates of the intersection of the vertical line and the terrain triangle:

X＝a (7)

Y＝b (8)

Z＝z1–(A(a-x1)+B(b-y1))/C (9)

Next, we need to further determine whether the intersection is inside the triangle patch. The existing Point In Polygon algorithm can be used to determine this. If the intersection is inside a terrain triangle patch, the vertical coordinate Z value of the intersection is the elevation value of the control point on the center line of the lane. That is, the vertical coordinate of the intersection is used as the height value of the lane where the control point is located. The X, Y, and Z coordinates of the control point on the center line of the lane are obtained.

Corresponding to the above method, the second aspect of the present invention further provides a three-dimensional lane model generation system, including:

at least one processor;

at least one memory for storing at least one program;

When the at least one program is executed by the at least one processor, the at least one processor implements the three-dimensional lane model generation method described in the first aspect embodiment.

The contents of the above method embodiments are all applicable to the present system embodiments. The functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the three-dimensional lane model generation system, and uses various interfaces and lines to connect various parts of the entire three-dimensional lane model generation system operable device.

The memory can be used to store the computer program and/or module, and the processor realizes various functions of the three-dimensional lane model generation system by running or executing the computer program and/or module stored in the memory, and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area can store data created according to the use of the mobile phone (such as audio data, a phone book, etc.), etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart-Media-Card, SMC), a secure digital (Secure-Digital, SD) card, a flash card (Flash-Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

Although the description of the present disclosure has been quite detailed and specifically describes several described embodiments, it is not intended to be limited to any of these details or embodiments or any particular embodiment, but should be regarded as providing a broad possible interpretation of these claims by reference to the appended claims, taking into account the prior art, so as to effectively cover the intended scope of the present disclosure. In addition, the above description of the present disclosure is based on the embodiments foreseeable by the inventor, and its purpose is to provide a useful description, and those non-substantial changes to the present disclosure that have not yet been foreseen may still represent equivalent changes to the present disclosure.

Claims (4)

1. A three-dimensional lane model generation method, characterized by comprising: Convert the lane layer from the latitude and longitude coordinate system to the projection coordinate system; Generate the center line and edge line of the lane in the projected coordinate system; Divide the lane into multiple continuous triangular patches and construct the two-dimensional coordinates of each triangular patch; The lane DEM data is used as the height value of each triangular face to construct the three-dimensional coordinates of each triangular face; Connect the triangular facets in sequence to obtain a three-dimensional lane model; The step of generating the center line and edge line of the lane in the projection coordinate system includes: Obtaining the lane coordinates in the projection coordinate system, finding the middle value of the lane coordinates, and using the middle value as the centerline coordinates of the lane; According to the number and width of lanes, the buffer distance of lanes is obtained; Taking the center line of the lane as the reference, the center line of the lane is offset to both sides according to the buffer distance of the lane to obtain the edge lines of the two lanes; The lane is divided into a plurality of continuous triangular facets and the two-dimensional coordinates of each triangular facet are constructed, including: The center line and the edge line of the lane are divided into multiple continuous straight line segments, and the connection point of two adjacent straight line segments is taken as the vertex; Generate two triangular facets from two opposite straight line segments, and connect the vertices of each triangular facet in a counterclockwise direction, so as to divide the lane into multiple connected triangular facets; Construct the two-dimensional coordinates of each triangle according to the two-dimensional coordinates of each vertex; The method of using the lane DEM data as the height value of each triangular facet to construct the three-dimensional coordinates of each triangular facet includes: The DEM data of the vertex in the triangular patch is used as the height value of the vertex, so as to obtain the three-dimensional coordinates of the vertex in each triangular patch; Calculate the ordinate of the center line according to the three-dimensional coordinates of the vertices in each triangular face; The ordinate of the center line is used as the height value of the lane, and the height value of the lane is combined with the two-dimensional coordinates of the triangular patch to obtain the three-dimensional coordinates of the triangular patch; The step of calculating the ordinate of the center line according to the three-dimensional coordinates of the vertex includes: Set the three-dimensional coordinates of any control point on the center line, obtain the two-dimensional coordinates of the control point, and determine the equation of the straight line passing through the control point and perpendicular to the XOY plane; Establish the plane equation of the triangle according to the three vertices of the triangle; Obtaining the ordinate of the control point according to the straight line equation and the plane equation; The ordinate of the center line is obtained based on the ordinates of all control points on the center line. 2. The method for generating a three-dimensional lane model according to claim 1, characterized in that before taking the longitudinal coordinate of the center line as the height value of the lane, the method comprises: Determine whether the control point is inside the triangular patch, and if so, use the ordinate of the control point as the height value of the lane where the control point is located; Make sure that all control points on the center line are inside the corresponding triangles. 3. The method for generating a three-dimensional lane model according to claim 1, wherein the step of sequentially connecting triangular facets to obtain a three-dimensional lane model comprises: Calculate the UV coordinates corresponding to each control point, perform continuous mapping on each triangle patch, and output a three-dimensional lane model. 4. A three-dimensional lane model generation system, characterized by comprising: at least one processor; at least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the three-dimensional lane model generation method as described in any one of claims 1-3.

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