Method, device, electronic equipment and computer program product for determining road elevation

Abstract

The method comprises the following steps: obtaining labeled road data and high-precision road data of a target area; the target area comprises at least one target road; extracting control position points on the target road based on the labeled road data; the control position points comprise two nodes of the target road and position points with elevation constraint limits; determining the labeled elevation of a first control point with known high-precision elevation among the control position points based on the high-precision road data; determining the labeled elevation of the first control point and a second control point with unknown high-precision elevation among the control position points based on the labeled elevation of the first control point, the elevation constraint limit and a slope constraint limit; the slope constraint limit comprises a fixed value of road slope between two adjacent control position points on the same target road.

Description

Technical Field

[0001] This disclosure relates to the field of location information service technology, specifically to a method, apparatus, electronic device, and computer program product for determining road elevation. Background Technology

[0002] Map products are constantly exploring various methods to describe surrounding environmental information, gradually evolving from 2D to 3D representation. To more completely represent geographic surface morphology, it's necessary to introduce road elevation data and build 3D road models. However, current standard-precision road data lacks road elevation information, while high-precision road data, although containing elevation information, only covers a portion of roads, such as urban expressways and highways. Full coverage is still a long way off and not currently feasible.

[0003] Therefore, a solution is needed to determine the elevation information of roads in the standard road data, so as to provide a data foundation for building a three-dimensional road model. Summary of the Invention

[0004] This disclosure provides a method, apparatus, electronic device, and computer program product for determining road elevation.

[0005] In a first aspect, this disclosure provides a method for determining road elevation, comprising:

[0006] Acquire standard and high-precision road data for the target area; the target area includes at least one target road.

[0007] Based on the standard and refined road data, control location points are extracted on the target road; the control location points include two nodes of the target road and location points with elevation constraints.

[0008] Based on the high-precision road data, determine the standard elevation of the first control point among the control location points whose high-precision elevation is known;

[0009] The precise elevations of the first control point and the second control point with unknown high-precision elevations are determined based on the precise elevation of the first control point, the elevation constraint, and the slope constraint. The slope constraint includes a fixed road slope between two adjacent control points on the same target road.

[0010] Furthermore, the elevation constraints include one or more combinations of road-to-road height constraints and elevation consistency constraints.

[0011] Further, based on the high-precision road data, determining the precise elevation of the first control point among the control location points with known high-precision elevation includes:

[0012] The target road is matched with the high-precision road data based on the road mapping relationship between the standard road data and the high-precision road data;

[0013] When the target road is completely covered by the high-precision road data, all control position points on the target road are determined as first control points, and the standard elevation of the first control points is obtained by mapping from the high-precision road data.

[0014] When the target road is partially covered by the high-precision road data, the control position point of the part of the target road covered by the high-precision road data is determined as the first control point, and a new first control point is generated based on the boundary between the covered and uncovered parts of the target road, and the standard elevation of the first control point is obtained by mapping from the high-precision road data.

[0015] Further, based on the precise elevation of the first control point, the elevation constraints, and the slope constraints, the precise elevations of the first control point and the second control point with unknown high-precision elevation among the control location points are determined, including:

[0016] Choose one as the current starting point from either the first control point or a second control point that has elevation constraints on other control point locations;

[0017] Starting from the current starting point, traverse the surrounding control points. Calculate the standard elevation of the second control point based on the standard elevation of the current starting point, the elevation constraints and slope constraints between the current starting point and the traversed surrounding second control points, until the traversal stop condition is met.

[0018] Select the next starting point as the current starting point, and repeat the process of starting from the current starting point and traversing the surrounding control points. Calculate the standard elevation of the second control point based on the standard elevation of the current starting point, the elevation constraints and slope constraints between the current starting point and the traversed surrounding second control points, until the traversal stop condition is met.

[0019] Further, the precise elevation of the second control point is calculated based on the precise elevation of the current starting point, the elevation constraints and slope constraints between the current starting point and the surrounding second control points, including:

[0020] The precise elevation of the second control point currently being traversed is calculated based on the precise elevation of the current starting point, the road layer height parameter, and / or the road slope parameter; the road layer height parameter is used to limit the layer height interval between upper and lower roads with the elevation constraint, and the road slope parameter is used to limit the slope of the line connecting two adjacent control position points on the same target road.

[0021] Furthermore, the method also includes:

[0022] After completing one round of traversal, obtain the new road layer height parameters and the new road slope parameters;

[0023] Choose one as the current starting point from either the first control point or a second control point that has elevation constraints on other control point locations;

[0024] Starting from the current starting point, traverse the surrounding control points. If the second control point being traversed in the current traversal does not meet the limitations of the road layer height parameters and / or road slope parameters used in the previous traversal, calculate the standard elevation of the second control point being traversed in the current traversal based on the standard elevation of the current starting point, the new road layer height parameters, and / or the new road slope parameters.

[0025] Furthermore, before selecting either the first control point or a second control point with elevation constraints on other control locations as the current starting point, the method further includes:

[0026] The first control point and the second control point are sorted in a forward order and in a reverse order according to the hierarchical relationship between multiple target roads from bottom to top and from top to bottom, respectively, to obtain the forward sorting result and the reverse sorting result.

[0027] Selecting a control point as the current starting point from either the first control point or a second control point that has elevation constraints on other control locations includes:

[0028] Based on the forward and / or reverse sorting results from front to back, the first control point that is ranked first and the second control point that has elevation constraints on other control point locations are selected as the current starting point.

[0029] Furthermore, the traversal stopping condition includes one or more combinations of the following:

[0030] The currently traversed surrounding control points are the first control points;

[0031] The currently traversed surrounding control point is the second control point that has already been traversed;

[0032] The current traversed surrounding control point is the second control point, and the current calculated standard elevation for the second control point is greater than or equal to the previously calculated standard elevation.

[0033] Furthermore, before determining the precise elevation of the second control point with an unknown precise elevation among the control location points based on the precise elevation of the first control point and the elevation constraints, the method further includes:

[0034] Based on the precise elevation of the first control point and the initial road slope parameters, the initial elevation of the second control point is calculated, such that the second control point adjacent to the first control point on the same target road satisfies the constraint of the initial road slope parameters.

[0035] Furthermore, starting from the current starting point, traverse the surrounding control location points, including:

[0036] Based on the distances from the current starting point in ascending order, traverse the surrounding control points of the current starting point.

[0037] Furthermore, before determining the precise elevations of the first control point and the second control point with unknown precise elevations among the control location points based on the precise elevation of the first control point, the elevation constraints, and the slope constraints, the method further includes:

[0038] Based on the precise elevation of two adjacent control points on the same target road, calculate the precise elevation of at least one point between the two adjacent control points on the target road.

[0039] Secondly, this disclosure provides a location-based service provision method, which utilizes the method described in the first aspect to provide location-based services to a service recipient. The location-based services include one or more of navigation, map rendering, and route planning.

[0040] Thirdly, this disclosure provides a device for determining road elevation, comprising:

[0041] The first acquisition module is configured to acquire standard and high-precision road data and high-precision road data of a target area; the target area includes at least one target road.

[0042] The extraction module is configured to extract control location points on the target road based on the standard road data; the control location points include two nodes of the target road and location points with elevation constraints.

[0043] The first determining module is configured to determine the standard elevation of a first control point with known high-precision elevation among the control location points based on the high-precision road data.

[0044] The second determining module is configured to determine the standard elevation of the first control point and the second control point whose high-precision elevation is unknown among the control location points based on the standard elevation of the first control point, the elevation constraint, and the slope constraint; the slope constraint includes a fixed road slope between two adjacent control location points on the same target road.

[0045] The function can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above function.

[0046] In one possible design, the above-described device includes a memory and a processor. The memory stores one or more computer instructions that support the device in performing the corresponding methods described above, and the processor is configured to execute the computer instructions stored in the memory. The device may also include a communication interface for communicating with other devices or communication networks.

[0047] Fourthly, embodiments of this disclosure provide an electronic device including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the method described in any of the above aspects.

[0048] Fifthly, embodiments of this disclosure provide a computer-readable storage medium for storing computer instructions used by any of the above-described devices, which, when executed by a processor, are used to implement the methods described in any of the above aspects.

[0049] In a sixth aspect, embodiments of this disclosure provide a computer program product comprising computer instructions which, when executed by a processor, are used to implement the methods described in any of the preceding aspects.

[0050] The technical solutions provided in this disclosure may have the following beneficial effects:

[0051] This embodiment of the disclosure targets a target road whose elevation is not expressed in the high-precision road data. It acquires the high-precision road data and related high-precision road data for the target road, and extracts control points on the target road using the high-precision road data. These control points include two nodes on the target road and a point with elevation constraints. The high-precision road data is used to divide the control points into a first control point with known high-precision elevation and a second control point with unknown high-precision elevation. Then, the high-precision elevation of the first control point is determined based on its high-precision elevation. Furthermore, the high-precision elevation, elevation constraints, and slope constraints of the first control point are used to derive and calculate the high-precision elevation of the second control point. In this way, the high-precision elevation of all control points on all roads in the high-precision road data covering the entire area can be calculated using high-precision road data with a limited coverage area. This gives the high-precision road data the ability to express elevation information, enabling the creation of a 3D road model even without high-precision data support, thereby improving the data representation capabilities of the electronic map.

[0052] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0053] Other features, objects, and advantages of this disclosure will become more apparent from the following detailed description of non-limiting embodiments, taken in conjunction with the accompanying drawings. In the drawings:

[0054] Figure 1 A flowchart illustrating a method for determining road elevation according to an embodiment of the present disclosure is shown;

[0055] Figure 2 This diagram illustrates the effect of control position point extraction according to an embodiment of the present disclosure.

[0056] Figure 3 A schematic diagram illustrating an implementation flow of a method for determining road elevation according to an embodiment of the present disclosure is shown.

[0057] Figure 4 A structural block diagram of a road elevation determination device according to an embodiment of the present disclosure is shown.

[0058] Figure 5 This is a schematic diagram of the structure of an electronic device suitable for implementing a method for determining road elevation and / or a location-based service provision method according to an embodiment of this disclosure. Detailed Implementation

[0059] In the following, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings to enable those skilled in the art to readily implement them. Furthermore, for clarity, portions unrelated to the description of the exemplary embodiments have been omitted from the drawings.

[0060] In this disclosure, it should be understood that terms such as “comprising” or “having” are intended to indicate the presence of features, figures, steps, behaviors, components, parts or combinations thereof disclosed in this specification, and do not preclude the possibility of the presence or addition of one or more other features, figures, steps, behaviors, components, parts or combinations thereof.

[0061] It should also be noted that, unless otherwise specified, the embodiments and features described in this disclosure can be combined with each other. This disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0062] The details of the embodiments of this disclosure are described in detail below through specific examples.

[0063] Figure 1 A flowchart illustrating a method for determining road elevation according to an embodiment of this disclosure is shown. Figure 1 As shown, the method for determining the road elevation includes the following steps:

[0064] In step S101, standard and high-precision road data of the target area are acquired; the target area includes at least one target road.

[0065] In step S102, control location points on the target road are extracted based on the standard road data; the control location points include two nodes of the target road and location points with elevation constraints.

[0066] In step S103, the standard elevation of the first control point with known high-precision elevation among the control location points is determined based on the high-precision road data;

[0067] In step S104, the precise elevations of the first control point and the second control point with unknown high-precision elevation are determined based on the precise elevation of the first control point, the elevation constraint, and the slope constraint. The slope constraint includes a fixed road slope between two adjacent control points on the same target road.

[0068] In this embodiment, the method for determining the road elevation can be executed on a server. The target area can be any area on an electronic map that includes the target road, and this area can include one or more target roads.

[0069] In some embodiments, the target road can be all or part of the roads within a defined area. As described in the background section, current high-precision road data does not cover all areas; that is, some areas have corresponding high-precision road data, while most areas do not. It should be noted that the target area is an area where at least a portion has corresponding high-precision road data. In other words, at least some target roads within the target area are wholly or partially covered by high-precision road data, and at least some target roads are not covered by high-precision road data or are partially not covered.

[0070] Therefore, the target road within the target area can be a road that is fully covered, partially covered, or not covered by high-precision road data. One or two nodes of a target road that is fully or partially covered by high-precision road data have corresponding high-precision data, such as elevation information, within the high-precision road data. This can be understood as the elevation information of one or two nodes of the target road that is fully or partially covered by high-precision road data already existing in the high-precision road data; that is, the elevation information of these one or two nodes is known. On the other hand, two nodes on a target road that are not covered by high-precision road data do not have corresponding high-precision road data, and their elevation information is unknown.

[0071] Standard-precision road data can be road data from ordinary map data, i.e., road data from standard-precision map data, while high-precision road data can be road data from high-precision map data. Currently, standard-precision road data basically covers the entire area, meaning that all roads in real life are represented in standard-precision road data; while high-precision road data has a smaller coverage, only covering a portion of real-world roads, such as urban expressways, highways, and important intersections, while other roads do not yet have corresponding high-precision road data.

[0072] High-definition map (HD map) data provides precise vehicle location information and rich road element data. It can help autonomous driving equipment anticipate complex road conditions, slopes, curvatures, and headings, enabling it to better avoid potential risks and is key to achieving autonomous driving.

[0073] Street Directory Map (SD Map) is a traditional navigation electronic map. It is a map stored and viewed digitally using computer technology. It indirectly serves users for retrieval, positioning, route planning and navigation through mobile devices such as in-vehicle devices and mobile phones.

[0074] Standard-precision road data refers to the relatively low-precision road network data typically used by navigation systems during navigation. In traditional navigation guidance, the road information displayed on the navigation page is primarily based on standard-precision road data. High-precision road data, on the other hand, offers significantly higher precision and more detailed representations of terrain features compared to standard-precision road network data. High-precision road data not only includes high-precision coordinates but also accurate lane shapes, and further details such as slope, curvature, heading, elevation, and lateral tilt for each lane.

[0075] Control points can be one or more points on a target road in the real world, and these points have corresponding data representations in the refined road data. In some embodiments, two nodes of the target road (in the refined road data, the road is represented as a line segment, and the two nodes of the target road are the two endpoints of the line segment represented by the target road in the refined road data) can serve as two control points of the target road. In other embodiments, a point on the target road can also be used as a control point when there are elevation constraints between it and one or more points on other roads, or when there are elevation constraints between some points on the target road.

[0076] In some embodiments, the elevation constraint restriction includes one or more combinations of road-to-road level height constraint restrictions and elevation consistency constraint restrictions. A location point with an elevation constraint restriction can be understood as two location points on the same target road having certain constraints on each other's elevations. For example, two location points on the same target road may have corresponding and identical elevations, or a location point on the current target road may have certain constraints on the elevations of location points on other roads. For instance, the elevation of a location point at the intersection of upper and lower level roads may have a level height constraint restriction, where the elevation of the location point at the intersection of the upper level road is the elevation of the location point at the intersection of the lower level road plus the level height distance.

[0077] In some embodiments, control location points can be extracted using the following types:

[0078] 1. Two nodes of the target road; Each road in the standard road data has two nodes, and the line connecting the two nodes according to the actual road direction represents the road.

[0079] 2. Location pairs with upper and lower layer overlap relationships; the upper and lower layer overlap relationships can be determined based on the standard road data. The two location pairs with upper and lower layer overlap relationships are located at the intersection of the upper and lower roads, respectively.

[0080] 3. Location points with consistent elevation; for example, the elevations of two relative locations on opposing roads must be consistent, otherwise the roads are not on the same plane. This type of location point pair with consistent elevation is usually achieved by finding a control point through other means and then extracting another control point whose elevation needs to be consistent with that existing control point. Another example is the need for consistent elevations for left-turn intersection pairs. A left-turn intersection pair can be understood as the intersection of the starting point of the left-turn line on the current target road and the intersection of the extension of that left-turn line with the next target road after turning left from the current target road to the next target road. This is because points on the left-turn line should have consistent elevations.

[0081] Figure 2 This diagram illustrates the effect of control position point extraction according to an embodiment of the present disclosure. Figure 2 As shown, points starting with C are control points. C1 and C2 are control points at the junctions of two roads. C4, C5, C9, and C13 are control points with overlapping relationships. C16 and C17 are control points at left-hand intersections. C14, C15, and C18 are control points where the elevations of the up and down roads need to be consistent.

[0082] There is a road mapping relationship between standard-precision road data and high-precision road data, and this mapping relationship is generated when the high-precision road data is produced. The elevation information of various points on a certain road in the high-precision road data can also be mapped to the standard-precision road data, serving as the elevation information of the same road in the standard-precision road data. To distinguish between the elevation information in the high-precision road data and the elevation information in the standard-precision road data, this embodiment of the disclosure refers to the elevation information expressed in the high-precision road data as high-precision elevation, and the elevation information expressed in the standard-precision road data as standard-precision elevation.

[0083] After extracting control points from the standard-precision road data, they can be matched with high-precision road data to obtain the elevation information of the control points from the high-precision road data. Since the high-precision road data only covers a portion of the area, only some control points within that area may have corresponding elevation information in the high-precision road data.

[0084] As mentioned above, some target roads within the target area are fully or partially covered by high-precision road data. Therefore, based on the high-precision road data, the control points of all or some target roads within the target area can be divided into first control points with known high-precision elevations and second control points with unknown high-precision elevations. The first control point is a control point whose elevation information exists in the high-precision road data; that is, the first control point is a control point with known elevation. The second control point is a control point with unknown elevation. At least one first control point and at least one second control point exist on each target road within the target area.

[0085] Because elevation information is expressed differently in high-precision road data and standard-precision road data, after identifying the first and second control points, the high-precision elevation information of the first control point in the high-precision road data can be mapped to the standard-precision elevation information in the standard-precision road data. High-precision elevation mapping can then express the elevation information of the first control point in the high-precision road data in the standard-precision road data according to the methods specified for standard-precision road data.

[0086] In this embodiment, the standard elevation of a second control point with unknown elevation information can be determined based on the high-precision elevation of a first control point on a target road, elevation constraints, and slope constraints between multiple control points on the same target road. Elevation constraints may exist between first control points on different target roads, between first and second control points, and between second control points. Furthermore, at least slope constraints exist between adjacent first control points, between first and second control points, and between second control points on the same target road. It should be noted that slope constraints between first control points can be disregarded in this embodiment, as the standard elevation of the first control point can be directly obtained from the high-precision elevation. The slope constraint refers to a fixed value for the slope (i.e., gradient) of the road between two adjacent control points (which can be either first or second control points) on the same target road. This fixed value is predetermined, and the standard elevation of the other control point can be determined based on the standard elevation of one of the two adjacent control points. Since the high-precision elevation of the first control point is known, based on the mapping relationship between the high-precision road data and the standard-precision road data, the standard-precision elevation of the first control point can be obtained based on the high-precision elevation of the first control point and the mapping relationship. Then, the standard-precision elevation of the second control point can be calculated based on the standard-precision elevation of the first control point, elevation constraints, and slope constraints.

[0087] In some embodiments, one of the first control points can be used as the starting point. By traversing the second control points that have elevation constraints and slope constraints with the first control point, the standard elevation of the second control point can be calculated based on the elevation constraints, slope constraints and the standard elevation of the first control point. Then, the next first control point is selected as the starting point, and the above process is repeated.

[0088] For example, if a first control point of the target road is selected as the starting point, the precise elevation of one or more second control points that have the same elevation as the first control point can be determined. That is, the precise elevation of one or more second control points is equal to the precise elevation of the first control point. Under the condition of a specified slope, if the precise elevation of a second control point that is adjacent to the first control point and located on the same target road meets the slope requirement, the precise elevation of the second control point can be calculated based on the precise elevation of the first control point and the slope.

[0089] It should be noted that the final result obtained in this embodiment is the precise elevation of the first and second control points on the target road within the target area.

[0090] This embodiment of the disclosure targets a target road whose elevation is not expressed in the high-precision road data. It acquires the high-precision road data and related high-precision road data for the target road, and extracts control points on the target road using the high-precision road data. These control points include two nodes on the target road and a point with elevation constraints. The high-precision road data is used to divide the control points into a first control point with known high-precision elevation and a second control point with unknown high-precision elevation. Then, the high-precision elevation of the first control point is determined based on its high-precision elevation. Furthermore, the high-precision elevation, elevation constraints, and slope constraints of the first control point are used to derive and calculate the high-precision elevation of the second control point. In this way, the high-precision elevation of all control points on all roads in the high-precision road data covering the entire area can be calculated using high-precision road data with a limited coverage area. This gives the high-precision road data the ability to express elevation information, enabling the creation of a 3D road model even without high-precision data support, thereby improving the data representation capabilities of the electronic map.

[0091] In an optional implementation of this embodiment, step S103, namely, determining the standard elevation of the first control point with known high-precision elevation among the control location points based on the high-precision road data, further includes the following steps:

[0092] The target road is matched with the high-precision road data based on the road mapping relationship between the standard road data and the high-precision road data;

[0093] When the target road is completely covered by the high-precision road data, all control position points on the target road are determined as first control points, and the standard elevation of the first control points is obtained by mapping from the high-precision road data.

[0094] When the target road is partially covered by the high-precision road data, the control position point of the part of the target road covered by the high-precision road data is determined as the first control point, and a new first control point is generated based on the boundary between the covered and uncovered parts of the target road, and the standard elevation of the first control point is obtained by mapping from the high-precision road data.

[0095] In this optional implementation, as described above, the target road may be fully, partially, or not covered by high-precision road data. When the high-precision road data fully covers the target road, all control points on the target road have corresponding elevation information in the high-precision road data. Therefore, the standard elevation of these control points in the standard-precision road data can be determined based on the road mapping relationship between the high-precision road data and the standard-precision road data. It should be noted that the road mapping relationship is known data, which has been generated and stored when the high-precision road data is established. This embodiment of the disclosure only needs to obtain the road mapping relationship directly from the electronic map data.

[0096] When the target road is partially covered by high-precision road data, the control point locations on the covered portion of the target road have corresponding high-precision data in the high-precision road data and can be identified as first control points. Their standard-precision elevation is then determined based on the road mapping relationship and the high-precision elevation of these first control points in the high-precision road data. However, when the target road is not covered by high-precision road data, all control point locations on the target road are second control points, and their high-precision elevations are unknown. It should be noted that if the target road is a connecting road at the boundary of the high-precision road data, the high-precision elevation of the node on the target road connecting to that boundary can be obtained from the high-precision road data, and this node is also a first control point.

[0097] Based on the above principles, other control points that are not identified as the first control point can be identified as the second control point with unknown high-precision elevation. Their high-precision elevation needs to be calculated based on the high-precision elevation of the first control point, elevation constraints, and slope constraints.

[0098] It should also be noted that when a target road is partially covered by high-precision road data, the intersection point between the covered and uncovered portions of the target road can be added as a control point, specifically the first control point. The high-precision elevation of this intersection point can be determined based on the high-precision road data, and then expressed as a standard-precision elevation based on both the high-precision and standard-precision road data. It's important to note that the high-precision and standard-precision elevations can be obtained by mapping the different elevation representations of the high-precision and standard-precision road data, and the actual desired elevation can be the same. In other words, the elevation representation of the same control point may differ in high-precision and standard-precision road data, but the actual desired elevation is the same.

[0099] In an optional implementation of this embodiment, step S104, which is the step of determining the standard elevation of the first control point and the second control point with unknown high-precision elevation among the control location points based on the standard elevation of the first control point, the elevation constraint, and the slope constraint, further includes the following steps:

[0100] Choose one as the current starting point from either the first control point or a second control point that has elevation constraints on other control point locations;

[0101] Starting from the current starting point, traverse the surrounding control points. Calculate the standard elevation of the second control point based on the standard elevation of the current starting point, the elevation constraints and slope constraints between the current starting point and the traversed surrounding second control points, until the traversal stop condition is met.

[0102] Select the next starting point as the current starting point, and repeat the process of starting from the current starting point and traversing the surrounding control points. Calculate the standard elevation of the second control point based on the standard elevation of the current starting point, the elevation constraints and slope constraints between the current starting point and the traversed surrounding second control points, until the traversal stop condition is met.

[0103] In this optional implementation, all or a portion of the target roads within the target area can be traversed. During the traversal, since the high-precision elevation of the first control point is known, the standard elevation can be mapped from this high-precision elevation. Therefore, the standard elevation of the traversed surrounding second control points can be calculated starting from the first control point. In other words, starting from one of the first control points, the surrounding second control points are traversed. The standard elevation of the second control point is unknown, but it can be calculated based on elevation and slope constraints between it and the first control point. These elevation constraints may include, but are not limited to, road-to-road height constraints and elevation consistency constraints. A height constraint means that in two target roads with an upper and lower layer overlap relationship, the height between their intersections is a set value. If the standard elevation of the intersection on one target road is known, the standard elevation of the intersection on the other target road can be calculated based on that height. An elevation consistency constraint means that the elevations between two points are equal, for example, the elevations of two relative points on opposite roads are equal. The slope consistency constraint refers to the requirement that the slope (i.e., the road surface inclination) of two adjacent points on the same target road be consistent. In this embodiment of the disclosure, by setting the layer height between upper and lower roads and the slope of two adjacent control points on the same target road, the relative elevation of each control point in the refined road data can be calculated.

[0104] During the traversal, the surrounding area of ​​the current starting point can be either the first control point or the second control point. When the traversal reaches the second control point that meets the traversal stopping condition, the traversal can be stopped, and the next starting point can be selected for traversal. The above steps are repeated until there is no next starting point that meets the condition, that is, until there is no starting point to choose from. For example, the first control point and the second control point that has elevation constraints with other control position points have both been selected and traversed.

[0105] In some embodiments, the traversal stopping condition may include, but is not limited to, one or more combinations of the following: the current traversed peripheral control point is a first control point, the current traversed peripheral control point is a second control point that has already been traversed, the current traversed peripheral control point is a second control point and the existing accurate elevation of the second control point is greater than the currently calculated accurate elevation.

[0106] In some embodiments, the first control point and the second control point with elevation constraints can be selected as the current starting point or the next starting point, and other surrounding control location points can be traversed starting from the current starting point or the next starting point.

[0107] In some embodiments, a first control point can be preferentially selected as the current starting point or the next starting point. When all first control points have been traversed, a second control point that satisfies the floor height constraint can be selected as the current starting point or the next starting point. When all second control points that satisfy the floor height constraint have also been traversed, a second control point that satisfies the elevation consistency constraint is selected as the current starting point or the next starting point. If all first control points, second control points that satisfy the elevation consistency constraint, or second control points that satisfy the floor height constraint have been traversed, the current round of traversal stops; if necessary, the next round of traversal can be performed.

[0108] In an optional implementation of this embodiment, the step of calculating the standard elevation of the second control point based on the standard elevation of the current starting point, the elevation constraints and slope constraints between the current starting point and the surrounding second control points, further includes the following steps:

[0109] The precise elevation of the second control point currently being traversed is calculated based on the precise elevation of the current starting point, the road layer height parameter, and / or the road slope parameter; the road layer height parameter is used to limit the layer height interval between upper and lower roads with the elevation constraint, and the road slope parameter is used to limit the slope of the line connecting two adjacent control position points on the same target road.

[0110] In this optional implementation, the road height and slope parameters currently in use can be preset. These parameters can be determined in advance based on data such as the actual road height or experience, and no specific restrictions are imposed here.

[0111] Given that the precise elevation of the current starting point is known, the precise elevation of the adjacent second control point located on the same target road as the current starting point can be calculated based on the road slope parameters. The precise elevation of the second control point on the upper or lower road with the same floor height constraint as the current starting point can also be calculated based on the road floor height parameters. Alternatively, the precise elevation of the second control point with the same elevation constraint as the current starting point can be determined.

[0112] In some embodiments, the precise elevation of adjacent second control points located on the same target road as the current starting point can be calculated using the following formula:

[0113] H neighbor =max(H neighbor h start -d×s)

[0114] Among them, H neighbor h is the precise elevation of the adjacent second control point. start Let be the standard elevation of the current starting point, d be the distance between the current starting point and the adjacent second control point, and s be the road slope parameter, i.e., the slope of the line connecting the current starting point and the adjacent second control point. In this formula, if the adjacent second control point has already calculated a standard elevation in other processes, such as the previous round of traversal or when traversing other target roads, then the higher of the newly calculated standard elevation and the calculated standard elevation can be selected as the standard elevation of the target road.

[0115] It should be noted that before calculating the precise elevation of the adjacent second control point using the above formula, the elevation of the second control point has already been initialized using the "fishing net" method, therefore H neighbor It must have at least one initial value greater than 0.

[0116] During initialization, the precise elevation of the first control point is used as a benchmark, and the precise elevation of the adjacent second control point is raised based on the initial road slope parameters. This raising process occurs when the elevation of the first control point is greater than the ground level. It should also be noted that the minimum initial precise elevation of the second control point is 0; a precise elevation of 0 indicates that the second control point is located on the ground.

[0117] In an optional implementation of this embodiment, the method further includes the following steps:

[0118] After completing one round of traversal, obtain the new road layer height parameters and the new road slope parameters;

[0119] Choose one as the current starting point from either the first control point or a second control point that has elevation constraints on other control point locations;

[0120] Starting from the current starting point, traverse the surrounding control points. If the second control point being traversed in the current traversal does not meet the limitations of the road layer height parameters and / or road slope parameters used in the previous traversal, calculate the standard elevation of the second control point being traversed in the current traversal based on the standard elevation of the current starting point, the new road layer height parameters, and / or the new road slope parameters.

[0121] In this optional implementation, as described above, during a round of traversal, the traversal starts from the first control point or the second control point with elevation constraints. The elevation of the traversed second control point is calculated. After the traversal stopping condition is met, the next starting point is selected, and further traversal is performed until there is no starting point that meets the condition.

[0122] After completing one round of traversal, it is also possible to check whether the precise elevation of all second control points has been calculated and whether the precise elevation meets all constraints, such as whether all elevation constraints are met. If all elevation constraints are met, the result calculated in the current traversal can be used as the final result, thereby ending the road elevation determination process. However, if the precise elevation of at least one second control point does not meet the elevation constraints, a new round of traversal can be started by changing the road layer height parameter and / or road slope parameter.

[0123] In the next round of traversal, since the previous round of traversal has already obtained the standard and precise elevations of some of the second control points that meet various elevation constraints, the standard and precise elevations of these second control points do not need to be recalculated during the traversal. Alternatively, by comparing the currently calculated standard and precise elevations with the previously calculated standard and precise elevations, the standard and precise elevation that best meets the requirements can be taken as the final result of the second control points.

[0124] In some embodiments, the traversal can still be performed in the same manner as the first round. When encountering a road level parameter and / or road slope parameter that does not meet the constraints of the previous round, the current precise elevation of the second control point can be calculated based on the road level parameter and / or road slope parameter of the current round. It should also be noted that if the currently calculated precise elevation of the second control point is less than or equal to the existing precise elevation of the second control point (which may be calculated in the previous iteration or obtained by traversing other target roads), the precise elevation of the second control point will not be updated, but the original precise elevation with the larger value will be retained.

[0125] In an optional implementation of this embodiment, before selecting either the first control point or a second control point that has elevation constraints with other control location points as the current starting point, the method further includes the following steps:

[0126] The first control point and the second control point are sorted in a forward order and in a reverse order according to the hierarchical relationship between multiple target roads from bottom to top and from top to bottom, respectively, to obtain the forward sorting result and the reverse sorting result.

[0127] The step of selecting a current starting point from the first control point or from a second control point that has elevation constraints on other control point locations further includes the following steps:

[0128] Based on the forward and / or reverse sorting results from front to back, the first control point that is ranked first and the second control point that has elevation constraints on other control point locations are selected as the current starting point.

[0129] In this optional implementation, the first and second control points can be pre-sorted before traversal. There are two sorting methods: forward sorting and reverse sorting. Forward sorting means sorting from bottom to top according to the hierarchical relationship between all target roads involved in the calculation; that is, the position control points (including the first and second control points) on lower-level target roads are sorted first, and the position control points on higher-level target roads are sorted last. Reverse sorting is the opposite of forward sorting, meaning that the position control points (including the first and second control points) on higher-level target roads are sorted from top to bottom according to the hierarchical relationship between all target roads involved in the calculation; that is, the position control points (including the first and second control points) on higher-level target roads are sorted first, and the position control points on lower-level target roads are sorted last.

[0130] Both sorting results can be used during the traversal.

[0131] In one iteration, based on the positive sorting result, the first control point at the top and the second control point with elevation constraints that have other control position points can be selected as the current starting point (for example, the first control point can be selected first, and if no first control point is available, the second control point with floor height constraints can be selected, and if no second control point with floor height constraints is available, the second control point with elevation consistency constraints can be selected). Then, based on the selected current starting point, the traversal is performed to calculate the standard and precise elevation of the traversed second control points.

[0132] After completing all traversals according to the forward sorting results, the traversal can be performed again based on the reverse sorting results. That is, based on the reverse sorting results, select the first control point at the top and the second control point with elevation constraints that have other control position points as the current starting point (for example, you can first select the first control point, and if there is no first control point to choose from, select the second control point with floor height constraints, and if there is no second control point with floor height constraints to choose from, select the second control point with elevation consistency constraints). Then, traverse based on the selected current starting point and calculate the standard and precise elevation of the traversed second control points.

[0133] After traversing both the forward and reverse sorting results, one iteration is complete. Each iteration can be performed in the same manner.

[0134] It should be noted that the road height and / or slope parameters used in each iteration are different. The road height parameter can decrease with the increase of the number of iterations, while the road slope parameter can increase with the increase of the number of iterations. That is, in the next iteration, the road height between roads decreases, while the slope increases. In some embodiments, three sets of road height and slope parameters can be set. After three iterations using these three sets of road height parameters, the accurate elevation of the second control point that meets the requirements can be obtained.

[0135] In an optional implementation of this embodiment, the traversal stopping condition includes one or more of the following combinations:

[0136] The currently traversed surrounding control points are the first control points;

[0137] The currently traversed surrounding control point is the second control point that has already been traversed;

[0138] The current traversed surrounding control point is the second control point, and the current calculated standard elevation for the second control point is greater than or equal to the previously calculated standard elevation.

[0139] In this optional implementation, when traversing the surrounding second control points based on the current starting point, the distinction between the first and second control points can be made beforehand. Instead, the traversal can be based on the current starting point and the surrounding control points can be traversed. If the first control point is encountered, the traversal can be stopped. Alternatively, if the standard elevation of the currently calculated second control point is less than or equal to the standard elevation of the second control point that has already been calculated (which may be calculated in the previous iteration or by traversing other target roads), the traversal can also be stopped and the next starting point can be selected.

[0140] Of course, it is understandable that when traversing from the following starting point, the above conditions should also be used as the traversal stopping condition.

[0141] In an optional implementation of this embodiment, before step S104, i.e., before determining the precise elevations of the first control point and the second control point with unknown precise elevations among the control location points based on the precise elevation of the first control point, the elevation constraint, and the slope constraint, the method further includes the following steps:

[0142] Based on the precise elevation of the first control point and the initial road slope parameters, the initial elevation of the second control point is calculated, such that the second control point adjacent to the first control point on the same target road satisfies the constraint of the initial road slope parameters.

[0143] In this optional implementation, as described above, a starting point is selected from the first control point and a second control point that has elevation constraints with other control points, and the precise elevation of the second control point is calculated through multiple iterations. In this embodiment, before performing multiple iterations, the precise elevation of the second control point can be initialized based on the precise elevation of the first control point and the initial road slope parameters.

[0144] It should be noted that the initial road slope parameter can be the same as or smaller than the road slope parameter used in the first iteration of the above multi-round iteration.

[0145] During initialization, the surrounding second control points can be traversed using only the first control point as the starting point. The precise elevation of adjacent second control points on the same target road as the first control point is calculated based on the initial road slope parameters. This ensures that the calculated precise elevation of the second control point satisfies the slope consistency constraint with the precise elevation of the first control point, meaning that the slope of the road between the first and second control points is the value of the initial road slope parameters.

[0146] It should be noted that during the initial process, the starting point can also be selected based on the results of forward and reverse sorting of the road's hierarchical relationship. That is, firstly, based on the forward sorting result, the first control point at the top of the sorted list can be selected as the starting point for traversal. Once the traversal stops, the next first control point at the top of the forward sorted list can be selected as the starting point for traversal, and so on, until no more first control points are available. Then, based on the reverse sorting result, the first control point at the top of the sorted list can be selected as the starting point for traversal, and so on, until no more first control points are available.

[0147] This embodiment of the disclosure starts from the fixed node at the break point of the high-precision road data (that is, the first control point of the target road), and gradually lowers the high-precision road data to the ground. When there is no elevation constraint, it tends to bring the road close to the ground.

[0148] The purpose of selecting the starting point according to the forward or reverse sorting results is to first fix the height of one point (such as the first control point with known precise elevation) and then raise (or lower) another point (the second control point with elevation constraints on the first control point) so that they meet the height difference requirement.

[0149] When raising (or lowering) a point (such as the first control point with a known precise elevation), due to the requirement of a gentle slope, other points connected to that point (adjacent second control points) can also be raised (or lowered), similar to the operation of "pulling a fishing net".

[0150] In an optional implementation of this embodiment, traversing the surrounding control point locations starting from the current starting point further includes the following steps:

[0151] Based on the distances from the current starting point in ascending order, traverse the surrounding control points of the current starting point.

[0152] In this optional implementation, after selecting the current starting point or the next starting point, when selecting the surrounding control points to be traversed based on the starting point, the traversal can be performed in order from closest to farthest based on the distance between the second control point and the starting point. That is, first select the control point closest to the starting point for processing, then select the control point second closest to the starting point, and so on, until all the second control points around the first control point have been traversed or the traversal stopping condition is met.

[0153] In some embodiments, the present disclosure may employ a greedy algorithm to select control points surrounding the starting point. For example, after selecting the starting point, Dijkstra's algorithm may be used to determine the traversal order of the control points surrounding the starting point. In this way, traversal complexity can be reduced and computational efficiency improved.

[0154] In an optional implementation of this embodiment, before determining the precise elevations of the first control point and the second control point with unknown precise elevations among the control location points based on the precise elevation of the first control point, the elevation constraint, and the slope constraint, the method further includes the following steps:

[0155] Based on the precise elevation of two adjacent control points on the same target road, calculate the precise elevation of at least one point between the two adjacent control points on the target road.

[0156] In this optional implementation, after the precise elevations of both the first and second control points are calculated, the precise elevation of any point between two adjacent control points on the target road can be obtained through interpolation. These two adjacent control points can be either the first or second control point. Since the precise elevations of these two adjacent control points have already been obtained, and the line connecting them corresponds to the line segment of the target road, the precise elevation of any point between the two adjacent control points can be calculated through interpolation. In this way, the precise elevations of all points on the target road can be calculated, compensating for the lack of elevation data in the precise road data.

[0157] Figure 3 This diagram illustrates an implementation flow of a method for determining road elevation according to an embodiment of the present disclosure. Figure 3As shown, data for the target area is acquired, and control points on each target road within the target area are determined. Using the mapping relationship between high-precision road data and standard-precision road data, the high-precision elevation of the first control point, whose high-precision elevation is known, is mapped to the standard-precision elevation in the standard-precision road data. The standard-precision elevation of the second control point adjacent to the first control point is initialized using the standard-precision elevation of the first control point and the initial road slope parameters. The first and second control points are sorted according to the hierarchical relationship between the target roads, from bottom to top and from top to bottom, respectively, to obtain forward and reverse sorting results. Iterative processing is performed according to the forward and reverse sorting results, i.e., the process of selecting a starting point and traversing the surrounding control points mentioned above, and the standard-precision elevation of the traversed second control points is calculated. After each iteration, a quality control function is run to check whether the calculated standard-precision elevation of the second control points meets the conditions. If there are second control points that do not meet the conditions, the next iteration is performed. After multiple iterations, the standard-precision elevations of all control points that meet the conditions can be obtained.

[0158] According to an embodiment of the present disclosure, a location-based service provision method provides location-based services to a service recipient using the aforementioned road elevation determination method. The location-based services include one or more of navigation, map rendering, and route planning.

[0159] In this embodiment, the location-based service provision method can be executed on a location service terminal, which can be a mobile phone, iPad, computer, smartwatch, vehicle in-vehicle equipment, etc. In this embodiment, a server can be used to add elevation information of various locations on the calibrated road data. This calibrated road data with added elevation information can be provided to a location server or navigation terminal to provide location services to the navigated object.

[0160] The service recipients can be mobile phones, iPads, computers, smartwatches, vehicles, robots, etc. The server can provide the refined road data obtained using the above methods to location servers or navigation terminals. During the service process for the service recipients, the location server and / or navigation system can provide services such as route planning, road rendering, and navigation based on this refined road data. For example, when displaying a large map of an intersection, the hierarchical relationship between upper and lower roads can be shown based on the road elevation information. Specific details regarding the process of determining road elevation can be found in the description of the road elevation determination method above, and will not be repeated here.

[0161] The following are embodiments of the apparatus disclosed herein, which can be used to execute embodiments of the method disclosed herein.

[0162] Figure 4A structural block diagram of a road elevation determination device according to an embodiment of the present disclosure is shown. This device can be implemented as part or all of an electronic device through software, hardware, or a combination of both. Figure 4 As shown, the device for determining the road elevation includes:

[0163] The first acquisition module 401 is configured to acquire standard and high-precision road data and high-precision road data of a target area; the target area includes at least one target road.

[0164] Extraction module 402 is configured to extract control location points on the target road based on the standard road data; the control location points include two nodes of the target road and location points with elevation constraints;

[0165] The first determining module 403 is configured to determine the standard elevation of a first control point with known high-precision elevation among the control location points based on the high-precision road data.

[0166] The second determining module 404 is configured to determine the standard elevation of the first control point and the second control point whose high-precision elevation is unknown among the control position points based on the standard elevation of the first control point, the elevation constraint limit, and the slope constraint limit; the slope constraint limit includes the road slope between two adjacent control position points on the same target road being a fixed value.

[0167] In this embodiment, the road elevation determination device can be executed on a server. The target area can be any area on an electronic map that includes the target road, and this area can include one or more target roads.

[0168] In some embodiments, the target road can be all or part of the roads within a defined area. As described in the background section, current high-precision road data does not cover all areas; that is, some areas have corresponding high-precision road data, while most areas do not. It should be noted that the target area is an area where at least a portion has corresponding high-precision road data. In other words, at least some target roads within the target area are wholly or partially covered by high-precision road data, and at least some target roads are not covered by high-precision road data or are partially not covered.

[0169] Therefore, the target road within the target area can be a road that is fully covered, partially covered, or not covered by high-precision road data. One or two nodes of a target road that is fully or partially covered by high-precision road data have corresponding high-precision data, such as elevation information, within the high-precision road data. This can be understood as the elevation information of one or two nodes of the target road that is fully or partially covered by high-precision road data already existing in the high-precision road data; that is, the elevation information of these one or two nodes is known. On the other hand, two nodes on a target road that are not covered by high-precision road data do not have corresponding high-precision road data, and their elevation information is unknown.

[0170] Standard-precision road data can be road data from ordinary map data, i.e., road data from standard-precision map data, while high-precision road data can be road data from high-precision map data. Currently, standard-precision road data basically covers the entire area, meaning that all roads in real life are represented in standard-precision road data; while high-precision road data has a smaller coverage, only covering a portion of real-world roads, such as urban expressways, highways, and important intersections, while other roads do not yet have corresponding high-precision road data.

[0171] High-definition map (HD map) data provides precise vehicle location information and rich road element data. It can help autonomous driving equipment anticipate complex road conditions, slopes, curvatures, and headings, enabling it to better avoid potential risks and is key to achieving autonomous driving.

[0172] Street Directory Map (SD Map) is a traditional navigation electronic map. It is a map stored and viewed digitally using computer technology. It indirectly serves users for retrieval, positioning, route planning and navigation through mobile devices such as in-vehicle devices and mobile phones.

[0173] Standard-precision road data refers to the relatively low-precision road network data typically used by navigation systems during navigation. In traditional navigation guidance, the road information displayed on the navigation page is primarily based on standard-precision road data. High-precision road data, on the other hand, offers significantly higher precision and more detailed representations of terrain features compared to standard-precision road network data. High-precision road data not only includes high-precision coordinates but also accurate lane shapes, and further details such as slope, curvature, heading, elevation, and lateral tilt for each lane.

[0174] Control points can be one or more points on a target road in the real world, and these points have corresponding data representations in the refined road data. In some embodiments, two nodes of the target road (in the refined road data, the road is represented as a line segment, and the two nodes of the target road are the two endpoints of the line segment represented by the target road in the refined road data) can serve as two control points of the target road. In other embodiments, a point on the target road can also be used as a control point when there are elevation constraints between it and one or more points on other roads, or when there are elevation constraints between some points on the target road.

[0175] In some embodiments, the elevation constraint restriction includes one or more combinations of road-to-road level height constraint restrictions and elevation consistency constraint restrictions. A location point with an elevation constraint restriction can be understood as two location points on the same target road having certain constraints on each other's elevations. For example, two location points on the same target road may have corresponding and identical elevations, or a location point on the current target road may have certain constraints on the elevations of location points on other roads. For instance, the elevation of a location point at the intersection of upper and lower level roads may have a level height constraint restriction, where the elevation of the location point at the intersection of the upper level road is the elevation of the location point at the intersection of the lower level road plus the level height distance.

[0176] In some embodiments, control location points can be extracted using the following types:

[0177] 1. Two nodes of the target road; Each road in the standard road data has two nodes, and the line connecting the two nodes according to the actual road direction represents the road.

[0178] 2. Location pairs with upper and lower layer overlap relationships; the upper and lower layer overlap relationships can be determined based on the standard road data. The two location pairs with upper and lower layer overlap relationships are located at the intersection of the upper and lower roads, respectively.

[0179] 3. Location points with consistent elevation; for example, the elevations of two relative locations on opposing roads must be consistent, otherwise the roads are not on the same plane. This type of location point pair with consistent elevation is usually achieved by finding a control point through other means and then extracting another control point whose elevation needs to be consistent with that existing control point. Another example is the need for consistent elevations for left-turn intersection pairs. A left-turn intersection pair can be understood as the intersection of the starting point of the left-turn line on the current target road and the intersection of the extension of that left-turn line with the next target road after turning left from the current target road to the next target road. This is because points on the left-turn line should have consistent elevations.

[0180] There is a road mapping relationship between standard-precision road data and high-precision road data, and this mapping relationship is generated when the high-precision road data is produced. The elevation information of various points on a certain road in the high-precision road data can also be mapped to the standard-precision road data, serving as the elevation information of the same road in the standard-precision road data. To distinguish between the elevation information in the high-precision road data and the elevation information in the standard-precision road data, this embodiment of the disclosure refers to the elevation information expressed in the high-precision road data as high-precision elevation, and the elevation information expressed in the standard-precision road data as standard-precision elevation.

[0181] After extracting control points from the standard-precision road data, they can be matched with high-precision road data to obtain the elevation information of the control points from the high-precision road data. Since the high-precision road data only covers a portion of the area, only some control points within that area may have corresponding elevation information in the high-precision road data.

[0182] As mentioned above, some target roads within the target area are fully or partially covered by high-precision road data. Therefore, based on the high-precision road data, the control points of all or some target roads within the target area can be divided into first control points with known high-precision elevations and second control points with unknown high-precision elevations. The first control point is a control point whose elevation information exists in the high-precision road data; that is, the first control point is a control point with known elevation. The second control point is a control point with unknown elevation. At least one first control point and at least one second control point exist on each target road within the target area.

[0183] Because elevation information is expressed differently in high-precision road data and standard-precision road data, after identifying the first and second control points, the high-precision elevation information of the first control point in the high-precision road data can be mapped to the standard-precision elevation information in the standard-precision road data. High-precision elevation mapping can then express the elevation information of the first control point in the high-precision road data in the standard-precision road data according to the methods specified for standard-precision road data.

[0184] In this embodiment, the standard elevation of a second control point with unknown elevation information can be determined based on the high-precision elevation of a first control point on a target road, elevation constraints, and slope constraints between multiple control points on the same target road. Elevation constraints may exist between first control points on different target roads, between first and second control points, and between second control points. Furthermore, at least slope constraints exist between adjacent first control points, between first and second control points, and between second control points on the same target road. It should be noted that slope constraints between first control points can be disregarded in this embodiment, as the standard elevation of the first control point can be directly mapped from the high-precision elevation. A slope constraint means that the slope (i.e., gradient) of the line connecting two control points (which can be either first or second control points) on the same target road is consistent. Since the high-precision elevation of the first control point is known, based on the mapping relationship between the high-precision road data and the standard-precision road data, the standard-precision elevation of the second control point can be obtained based on the high-precision elevation of the first control point and the mapping relationship. Then, the standard-precision elevation of the second control point can be calculated based on the standard-precision elevation of the first control point, elevation constraints, and slope constraints.

[0185] In some embodiments, one of the first control points can be used as the starting point. By traversing the second control points that have elevation constraints and slope constraints with the first control point, the standard elevation of the second control point can be calculated based on the elevation constraints, slope constraints and the standard elevation of the first control point. Then, the next first control point is selected as the starting point, and the above process is repeated.

[0186] For example, if a first control point of the target road is selected as the starting point, the precise elevation of one or more second control points that have the same elevation as the first control point can be determined. That is, the precise elevation of one or more second control points is equal to the precise elevation of the first control point. Under the condition of a specified slope, if the precise elevation of a second control point that is adjacent to the first control point and located on the same target road meets the slope requirement, the precise elevation of the second control point can be calculated based on the precise elevation of the first control point and the slope.

[0187] It should be noted that the embodiments disclosed herein ultimately yield the first and second control points on the target road within the target area.

[0188] This embodiment of the disclosure targets a target road whose elevation is not expressed in the high-precision road data. It acquires the high-precision road data and related high-precision road data for the target road, and extracts control points on the target road using the high-precision road data. These control points include two nodes on the target road and a point with elevation constraints. The high-precision road data is used to divide the control points into a first control point with known high-precision elevation and a second control point with unknown high-precision elevation. Then, the high-precision elevation of the first control point is determined based on its high-precision elevation. Furthermore, the high-precision elevation, elevation constraints, and slope constraints of the first control point are used to derive and calculate the high-precision elevation of the second control point. In this way, the high-precision elevation of all control points on all roads in the high-precision road data covering the entire area can be calculated using high-precision road data with a limited coverage area. This gives the high-precision road data the ability to express elevation information, enabling the creation of a 3D road model even without high-precision data support, thereby improving the data representation capabilities of the electronic map.

[0189] In an optional implementation of this embodiment, the first determining module includes:

[0190] The matching submodule is configured to match the target road with the high-precision road data based on the road mapping relationship between the standard-precision road data and the high-precision road data;

[0191] The first determining submodule is configured to determine all control position points on the target road as first control points when the target road is completely covered by the high-precision road data, and to obtain the standard elevation of the first control points from the high-precision road data.

[0192] The second determining submodule is configured to, when the target road is partially covered by the high-precision road data, determine the control position point of the part of the target road covered by the high-precision road data as the first control point, generate a new first control point based on the boundary between the covered and uncovered parts of the target road, and obtain the standard elevation of the first control point from the high-precision road data.

[0193] In this optional implementation, as described above, the target road may be fully, partially, or not covered by high-precision road data. When the high-precision road data fully covers the target road, all control points on the target road have corresponding elevation information in the high-precision road data. Therefore, the standard elevation of these control points in the standard-precision road data can be determined based on the road mapping relationship between the high-precision road data and the standard-precision road data. It should be noted that the road mapping relationship is known data, which has been generated and stored when the high-precision road data is established. This embodiment of the disclosure only needs to obtain the road mapping relationship directly from the electronic map data.

[0194] When the target road is partially covered by high-precision road data, the control point locations on the covered portion of the target road have corresponding high-precision data in the high-precision road data and can be identified as first control points. Their standard-precision elevation is then determined based on the road mapping relationship and the high-precision elevation of these first control points in the high-precision road data. However, when the target road is not covered by high-precision road data, all control point locations on the target road are second control points, and their high-precision elevations are unknown. It should be noted that if the target road is a connecting road at the boundary of the high-precision road data, the high-precision elevation of the node on the target road connecting to that boundary can be obtained from the high-precision road data, and this node is also a first control point.

[0195] Based on the above principles, other control points that are not identified as the first control point can be identified as the second control point with unknown high-precision elevation. Their high-precision elevation needs to be calculated based on the high-precision elevation of the first control point, elevation constraints, and slope constraints.

[0196] It should also be noted that when a target road is partially covered by high-precision road data, the intersection point between the covered and uncovered portions of the target road can be added as a control point, specifically the first control point. The high-precision elevation of this intersection point can be determined based on the high-precision road data, and then expressed as a standard-precision elevation based on both the high-precision and standard-precision road data. It's important to note that the high-precision and standard-precision elevations can be obtained by mapping the different elevation representations of the high-precision and standard-precision road data, and the actual desired elevation can be the same. In other words, the elevation representation of the same control point may differ in high-precision and standard-precision road data, but the actual desired elevation is the same.

[0197] In an optional implementation of this embodiment, the second determining module includes:

[0198] The first selection submodule is configured to select one as the current starting point from either the first control point or from a second control point that has elevation constraints on other control location points.

[0199] The first traversal submodule is configured to start from the current starting point, traverse the surrounding control point, and calculate the standard elevation of the second control point based on the standard elevation of the current starting point, the elevation constraints and slope constraints between the current starting point and the traversed surrounding second control point, until the traversal stop condition is met.

[0200] The second selection submodule is configured to select the next starting point and repeat the execution of the first traversal submodule.

[0201] In this optional implementation, all or a portion of the target roads within the target area can be traversed. During the traversal, since the high-precision elevation of the first control point is known, the standard elevation can be mapped from this high-precision elevation. Therefore, the standard elevation of the traversed surrounding second control points can be calculated starting from the first control point. In other words, starting from one of the first control points, the surrounding second control points are traversed. The standard elevation of the second control point is unknown, but it can be calculated based on elevation and slope constraints between it and the first control point. These elevation constraints may include, but are not limited to, road-to-road height constraints and elevation consistency constraints. A height constraint means that in two target roads with an upper and lower layer overlap relationship, the height between their intersections is a set value. If the standard elevation of the intersection on one target road is known, the standard elevation of the intersection on the other target road can be calculated based on that height. An elevation consistency constraint means that the elevations between two points are equal, for example, the elevations of two relative points on opposite roads are equal. The slope consistency constraint means that the slope (i.e., the slope of the road surface) is consistent between two adjacent points on the same target road.

[0202] During the traversal, the surrounding area of ​​the current starting point can be either the first control point or the second control point. When the traversal reaches the second control point that meets the traversal stopping condition, the traversal can be stopped, and the next starting point can be selected for traversal. The above steps are repeated until there is no next starting point that meets the condition, that is, until there is no starting point to choose from. For example, the first control point and the second control point that has elevation constraints with other control position points have both been selected and traversed.

[0203] In some embodiments, the traversal stopping condition may include, but is not limited to, one or more combinations of the following: the current traversed peripheral control point is a first control point, the current traversed peripheral control point is a second control point that has already been traversed, the current traversed peripheral control point is a second control point and the existing accurate elevation of the second control point is greater than the currently calculated accurate elevation.

[0204] In some embodiments, the first control point and the second control point with elevation constraints can be selected as the current starting point or the next starting point, and other surrounding control location points can be traversed starting from the current starting point or the next starting point.

[0205] In some embodiments, a first control point can be preferentially selected as the current starting point or the next starting point. When all first control points have been traversed, a second control point that satisfies the floor height constraint can be selected as the current starting point or the next starting point. When all second control points that satisfy the floor height constraint have also been traversed, a second control point that satisfies the elevation consistency constraint is selected as the current starting point or the next starting point. If all first control points, second control points that satisfy the elevation consistency constraint, or second control points that satisfy the floor height constraint have been traversed, the current round of traversal stops; if necessary, the next round of traversal can be performed.

[0206] In an optional implementation of this embodiment, the first traversal submodule includes:

[0207] The first calculation submodule is configured to calculate the standard elevation of the second control point currently being traversed based on the standard elevation of the current starting point, road layer height parameters, and / or road slope parameters; the road layer height parameters are used to limit the layer height interval between upper and lower roads with the elevation constraint, and the road slope parameters are used to limit the slope of the line connecting two adjacent control position points on the same target road.

[0208] In this optional implementation, the road height and slope parameters currently in use can be preset. These parameters can be determined in advance based on data such as the actual road height or experience, and no specific restrictions are imposed here.

[0209] Given that the precise elevation of the current starting point is known, the precise elevation of the adjacent second control point located on the same target road as the current starting point can be calculated based on the road slope parameters. The precise elevation of the second control point on the upper or lower road with the same floor height constraint as the current starting point can also be calculated based on the road floor height parameters. Alternatively, the precise elevation of the second control point with the same elevation constraint as the current starting point can be determined.

[0210] In some embodiments, the precise elevation of adjacent second control points located on the same target road as the current starting point can be calculated using the following formula:

[0211] H neighbor =max(H neighbor h start -d×s)

[0212] Among them, H neighbor h is the precise elevation of the adjacent second control point. startLet be the standard elevation of the current starting point, d be the distance between the current starting point and the adjacent second control point, and s be the road slope parameter, i.e., the slope of the line connecting the current starting point and the adjacent second control point. In this formula, if the adjacent second control point has already calculated a standard elevation in other processes, such as the previous round of traversal or when traversing other target roads, then the higher of the newly calculated standard elevation and the calculated standard elevation can be selected as the standard elevation of the target road.

[0213] In an optional implementation of this embodiment, the apparatus further includes:

[0214] The second acquisition module is configured to acquire new road layer height parameters and new road slope parameters after completing one round of traversal;

[0215] The selection module is configured to select one as the current starting point from either the first control point or a second control point that has elevation constraints on other control location points.

[0216] The traversal module is configured to start from the current starting point and traverse the surrounding control point. When the second control point being traversed in the current traversal does not meet the restrictions of the road layer height parameters and / or road slope parameters used in the previous traversal, the module calculates the standard elevation of the second control point being traversed in the current traversal based on the standard elevation of the current starting point, the new road layer height parameters, and / or the new road slope parameters.

[0217] In this optional implementation, as described above, during a round of traversal, the traversal starts from the first control point or the second control point with elevation constraints. The elevation of the traversed second control point is calculated. After the traversal stopping condition is met, the next starting point is selected, and further traversal is performed until there is no starting point that meets the condition.

[0218] After completing one round of traversal, it is also possible to check whether the precise elevation of all second control points has been calculated and whether the precise elevation meets all constraints, such as whether all elevation constraints are met. If all elevation constraints are met, the result calculated in the current traversal can be used as the final result, thereby ending the road elevation determination process. However, if the precise elevation of at least one second control point does not meet the elevation constraints, a new round of traversal can be started by changing the road layer height parameter and / or road slope parameter.

[0219] In the next round of traversal, since the previous round of traversal has already obtained the standard and precise elevations of some of the second control points that meet various elevation constraints, the standard and precise elevations of these second control points do not need to be recalculated during the traversal. Alternatively, by comparing the currently calculated standard and precise elevations with the previously calculated standard and precise elevations, the standard and precise elevation that best meets the requirements can be taken as the final result of the second control points.

[0220] In some embodiments, the traversal can still be performed in the same manner as the first round. When encountering a road level parameter and / or road slope parameter that does not meet the constraints of the previous round, the current precise elevation of the second control point can be calculated based on the road level parameter and / or road slope parameter of the current round. It should also be noted that if the currently calculated precise elevation of the second control point is less than or equal to the existing precise elevation of the second control point (which may be calculated in the previous iteration or obtained by traversing other target roads), the precise elevation of the second control point will not be updated, but the original precise elevation with the larger value will be retained.

[0221] In an optional implementation of this embodiment, before the first selection submodule, the device further includes:

[0222] The sorting module is configured to sort the first control point and the second control point in a forward sorting and a reverse sorting according to the hierarchical relationship between multiple target roads from bottom to top and from top to bottom, respectively, to obtain forward sorting results and reverse sorting results.

[0223] The first selection submodule includes:

[0224] The second selection submodule is configured to select the first control point, which is the first in the sorted order, and the second control point, which has elevation constraints on other control point locations, as the current starting point, based on the forward and / or reverse sorting results from front to back.

[0225] In this optional implementation, the first and second control points can be pre-sorted before traversal. There are two sorting methods: forward sorting and reverse sorting. Forward sorting means sorting from bottom to top according to the hierarchical relationship between all target roads involved in the calculation; that is, the position control points (including the first and second control points) on lower-level target roads are sorted first, and the position control points on higher-level target roads are sorted last. Reverse sorting is the opposite of forward sorting, meaning that the position control points (including the first and second control points) on higher-level target roads are sorted from top to bottom according to the hierarchical relationship between all target roads involved in the calculation; that is, the position control points (including the first and second control points) on higher-level target roads are sorted first, and the position control points on lower-level target roads are sorted last.

[0226] Both sorting results can be used during the traversal.

[0227] In one iteration, based on the positive sorting result, the first control point at the top and the second control point with elevation constraints that have other control position points can be selected as the current starting point (for example, the first control point can be selected first, and if no first control point is available, the second control point with floor height constraints can be selected, and if no second control point with floor height constraints is available, the second control point with elevation consistency constraints can be selected). Then, based on the selected current starting point, the traversal is performed to calculate the standard and precise elevation of the traversed second control points.

[0228] After completing all traversals according to the forward sorting results, the traversal can be performed again based on the reverse sorting results. That is, based on the reverse sorting results, select the first control point at the top and the second control point with elevation constraints that have other control position points as the current starting point (for example, you can first select the first control point, and if there is no first control point to choose from, select the second control point with floor height constraints, and if there is no second control point with floor height constraints to choose from, select the second control point with elevation consistency constraints). Then, traverse based on the selected current starting point and calculate the standard and precise elevation of the traversed second control points.

[0229] After traversing both the forward and reverse sorting results, one iteration is complete. Each iteration can be performed in the same manner.

[0230] It should be noted that the road height and / or slope parameters used in each iteration are different. The road height parameter can decrease with the increase of the number of iterations, while the road slope parameter can increase with the increase of the number of iterations. That is, in the next iteration, the road height between roads decreases, while the slope increases. In some embodiments, three sets of road height and slope parameters can be set. After three iterations using these three sets of road height parameters, the accurate elevation of the second control point that meets the requirements can be obtained.

[0231] In an optional implementation of this embodiment, the traversal stopping condition includes one or more of the following combinations:

[0232] The currently traversed surrounding control points are the first control points;

[0233] The currently traversed surrounding control point is the second control point that has already been traversed;

[0234] The current traversed surrounding control point is the second control point, and the current calculated standard elevation for the second control point is greater than or equal to the previously calculated standard elevation.

[0235] In this optional implementation, when traversing the surrounding second control points based on the current starting point, the distinction between the first and second control points can be made beforehand. Instead, the traversal can be based on the current starting point and the surrounding control points can be traversed. If the first control point is encountered, the traversal can be stopped. Alternatively, if the standard elevation of the currently calculated second control point is less than or equal to the standard elevation of the second control point that has already been calculated (which may be calculated in the previous iteration or by traversing other target roads), the traversal can also be stopped and the next starting point can be selected.

[0236] Of course, it is understandable that when traversing from the following starting point, the above conditions should also be used as the traversal stopping condition.

[0237] In an optional implementation of this embodiment, before the second determining module, the device further includes:

[0238] The first calculation module is configured to calculate the initial elevation of the second control point based on the precise elevation of the first control point and the initial road slope parameters, such that the second control point adjacent to the first control point on the same target road satisfies the constraint of the initial road slope parameters.

[0239] In this optional implementation, as described above, a starting point is selected from the first control point and a second control point that has elevation constraints with other control points, and the precise elevation of the second control point is calculated through multiple iterations. In this embodiment, before performing multiple iterations, the precise elevation of the second control point can be initialized based on the precise elevation of the first control point and the initial road slope parameters.

[0240] It should be noted that the initial road slope parameter can be the same as or smaller than the road slope parameter used in the first iteration of the above multi-round iteration.

[0241] During initialization, the surrounding second control points can be traversed using only the first control point as the starting point. The precise elevation of adjacent second control points on the same target road as the first control point is calculated based on the initial road slope parameters. This ensures that the calculated precise elevation of the second control point satisfies the slope consistency constraint with the precise elevation of the first control point, meaning that the slope of the road between the first and second control points is the value of the initial road slope parameters.

[0242] It should be noted that during the initial process, the starting point can also be selected based on the results of forward and reverse sorting of the road's hierarchical relationship. That is, firstly, based on the forward sorting result, the first control point at the top of the sorted list can be selected as the starting point for traversal. Once the traversal stops, the next first control point at the top of the forward sorted list can be selected as the starting point for traversal, and so on, until no more first control points are available. Then, based on the reverse sorting result, the first control point at the top of the sorted list can be selected as the starting point for traversal, and so on, until no more first control points are available.

[0243] This embodiment of the disclosure starts from the fixed node at the break point of the high-precision road data (that is, the first control point of the target road), and gradually lowers the high-precision road data to the ground. When there is no elevation constraint limit, it tends to bring the road close to the ground.

[0244] The purpose of selecting the starting point according to the forward or reverse sorting results is to first fix the height of one point (such as the first control point with known precise elevation) and then raise (or lower) another point (the second control point with elevation constraints on the first control point) so that they meet the height difference requirement.

[0245] When raising (or lowering) a point (such as the first control point with a known precise elevation), due to the requirement of a gentle slope, other points connected to that point (adjacent second control points) can also be raised (or lowered), similar to the operation of "pulling a fishing net".

[0246] In an optional implementation of this embodiment, the first traversal submodule includes:

[0247] The second traversal submodule is configured to traverse the surrounding control points of the current starting point in ascending order of distance from the current starting point.

[0248] In this optional implementation, after selecting the current starting point or the next starting point, when selecting the surrounding control points to be traversed based on the starting point, the traversal can be performed in order from closest to farthest based on the distance between the second control point and the starting point. That is, first select the control point closest to the starting point for processing, then select the control point second closest to the starting point, and so on, until all the second control points around the first control point have been traversed or the traversal stopping condition is met.

[0249] In some embodiments, the present disclosure may employ a greedy algorithm to select control points surrounding the starting point. For example, after selecting the starting point, Dijkstra's algorithm may be used to determine the traversal order of the control points surrounding the starting point. In this way, traversal complexity can be reduced and computational efficiency improved.

[0250] In an optional implementation of this embodiment, before the second determining module, the device further includes:

[0251] The second calculation module is configured to calculate the precise elevation of at least one point between two adjacent control points on the target road, based on the precise elevation of two adjacent control points on the same target road.

[0252] In this optional implementation, after the precise elevations of both the first and second control points are calculated, the precise elevation of any point between two adjacent control points on the target road can be obtained through interpolation. These two adjacent control points can be either the first or second control point. Since the precise elevations of these two adjacent control points have already been obtained, and the line connecting them corresponds to the line segment of the target road, the precise elevation of any point between the two adjacent control points can be calculated through interpolation. In this way, the precise elevations of all points on the target road can be calculated, compensating for the lack of elevation data in the precise road data.

[0253] Figure 5 This is a schematic diagram of the structure of an electronic device suitable for implementing a method for determining road elevation and / or a location-based service provision method according to an embodiment of this disclosure.

[0254] like Figure 5 As shown, the electronic device 500 includes a processing unit 501, which can be implemented as a CPU, GPU, FPGA, NPU, or other processing unit. The processing unit 501 can execute various processes according to any of the methods described above in this disclosure, based on a program stored in the read-only memory (ROM) 502 or a program loaded from the storage portion 508 into the random access memory (RAM) 503. The RAM 503 also stores various programs and data required for the operation of the electronic device 500. The processing unit 501, ROM 502, and RAM 503 are interconnected via a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0255] The following components are connected to I / O interface 505: an input section 506 including a keyboard, mouse, etc.; an output section 507 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; a storage section 508 including a hard disk, etc.; and a communication section 509 including a network interface card such as a LAN card, modem, etc. The communication section 509 performs communication processing via a network such as the Internet. A drive 510 is also connected to I / O interface 505 as needed. A removable medium 511, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on drive 510 as needed so that computer programs read from it can be installed into storage section 508 as needed.

[0256] In particular, according to embodiments of this disclosure, any of the methods described above in the embodiments of this disclosure can be implemented as a computer software program. For example, embodiments of this disclosure include a computer program product comprising a computer program tangibly embodied on a machine-readable medium, the computer program containing program code for performing any of the methods in the embodiments of this disclosure. In such an embodiment, the computer program can be downloaded and installed from a network via communication section 509, and / or installed from removable medium 511.

[0257] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0258] The units or modules described in the embodiments of this disclosure can be implemented in software or hardware. The described units or modules can also be located in a processor, and the names of these units or modules do not necessarily constitute a limitation on the unit or module itself.

[0259] In another aspect, this disclosure also provides a computer-readable storage medium, which may be a computer-readable storage medium included in the apparatus described in the above embodiments; or it may be a standalone computer-readable storage medium not assembled into a device. The computer-readable storage medium stores one or more programs that are used by one or more processors to perform the methods described in this disclosure.

[0260] The above description is merely a preferred embodiment of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features disclosed in this disclosure that have similar functions.

Claims

1. A method of determining the elevation of a road, wherein, include: Acquire standard and high-precision road data for the target area; the target area includes at least one target road. Based on the standard road data, control location points are extracted on the target road; the control location points include two nodes of the target road and location points with elevation constraints; wherein, the elevation constraints include one or more combinations of road-to-road height constraints and elevation consistency constraints. Based on the high-precision road data, determine the standard elevation of the first control point among the control location points whose high-precision elevation is known; The precise elevations of the first control point and the second control point with unknown high-precision elevations are determined based on the precise elevation of the first control point, the elevation constraint, and the slope constraint. The slope constraint includes a fixed road slope between two adjacent control points on the same target road.

2. The method of claim 1, wherein, Determining the precise elevation of the first control point with known high-precision elevation among the control location points based on the high-precision road data includes: The target road is matched with the high-precision road data based on the road mapping relationship between the standard road data and the high-precision road data; When the target road is completely covered by the high-precision road data, all control position points on the target road are determined as first control points, and the standard elevation of the first control points is obtained by mapping from the high-precision road data. When the target road is partially covered by the high-precision road data, the control position point of the part of the target road covered by the high-precision road data is determined as the first control point, and a new first control point is generated based on the boundary between the covered and uncovered parts of the target road, and the standard elevation of the first control point is obtained by mapping from the high-precision road data.

3. The method of claim 1, wherein, Based on the precise elevation of the first control point, the elevation constraints, and the slope constraints, determine the precise elevations of the first control point and the second control point with unknown precise elevation among the control location points, including: Choose one as the current starting point from either the first control point or a second control point that has elevation constraints on other control point locations; Starting from the current starting point, traverse the surrounding control points. Calculate the standard elevation of the second control point based on the standard elevation of the current starting point, the elevation constraints and slope constraints between the current starting point and the traversed surrounding second control points, until the traversal stop condition is met. Select the next starting point as the current starting point, and repeat the process of starting from the current starting point and traversing the surrounding control points. Calculate the standard elevation of the second control point based on the standard elevation of the current starting point, the elevation constraints and slope constraints between the current starting point and the traversed surrounding second control points, until the traversal stop condition is met.

4. The method according to claim 3, wherein, The precise elevation of the second control point is calculated based on the precise elevation of the current starting point, the elevation constraints and slope constraints between the current starting point and the surrounding second control points, including: The precise elevation of the second control point currently being traversed is calculated based on the precise elevation of the current starting point, the road layer height parameter, and / or the road slope parameter; the road layer height parameter is used to limit the layer height interval between upper and lower roads with the elevation constraint, and the road slope parameter is used to limit the slope of the line connecting two adjacent control position points on the same target road.

5. The method according to claim 3 or 4, wherein, The method further includes: After completing one round of traversal, obtain the new road layer height parameters and the new road slope parameters; Choose one as the current starting point from either the first control point or a second control point that has elevation constraints on other control point locations; Starting from the current starting point, traverse the surrounding control points. If the second control point being traversed in the current traversal does not meet the limitations of the road layer height parameters and / or road slope parameters used in the previous traversal, calculate the standard elevation of the second control point being traversed in the current traversal based on the standard elevation of the current starting point, the new road layer height parameters, and / or the new road slope parameters.

6. The method according to claim 3, wherein, Before selecting a current starting point from either the first control point or a second control point that has elevation constraints with other control point locations, the method further includes: The first control point and the second control point are sorted in a forward order and in a reverse order according to the hierarchical relationship between multiple target roads from bottom to top and from top to bottom, respectively, to obtain the forward sorting result and the reverse sorting result. Selecting a control point as the current starting point from either the first control point or a second control point that has elevation constraints on other control locations includes: Based on the forward and / or reverse sorting results from front to back, the first control point that is ranked first and the second control point that has elevation constraints on other control point locations are selected as the current starting point.

7. The method according to claim 3, wherein, The traversal stopping condition includes one or more of the following combinations: The currently traversed surrounding control points are the first control points; The currently traversed surrounding control point is the second control point that has already been traversed; The current traversed surrounding control point is the second control point, and the current calculated standard elevation for the second control point is greater than or equal to the previously calculated standard elevation.

8. The method according to any one of claims 1-4 and 6-7, wherein, Before determining the precise elevation of the second control point with an unknown precise elevation among the control location points based on the precise elevation of the first control point and the elevation constraints, the method further includes: Based on the precise elevation of the first control point and the initial road slope parameters, the initial elevation of the second control point is calculated, such that the second control point adjacent to the first control point on the same target road satisfies the constraint of the initial road slope parameters.

9. The method according to claim 3, wherein, Starting from the current starting point, traverse the surrounding control location points, including: Based on the distances from the current starting point in ascending order, traverse the surrounding control points of the current starting point.

10. The method according to any one of claims 1-4, 6-7, and 9, wherein, Before determining the precise elevations of the first control point and the second control point with unknown precise elevations based on the precise elevation of the first control point, the elevation constraints, and the slope constraints, the method further includes: Based on the precise elevation of two adjacent control points on the same target road, calculate the precise elevation of at least one point between the two adjacent control points on the target road.

11. A device for determining road elevation, wherein, include: The first acquisition module is configured to acquire standard and high-precision road data for the target area. The target area includes at least one target road; The extraction module is configured to extract control location points on the target road based on the standard road data; the control location points include two nodes of the target road and location points with elevation constraints; wherein, the elevation constraints include one or more combinations of road-to-road height constraints and elevation consistency constraints. The first determining module is configured to determine the standard elevation of a first control point with known high-precision elevation among the control location points based on the high-precision road data. The second determining module is configured to determine the standard elevation of the first control point and the second control point whose high-precision elevation is unknown among the control location points based on the standard elevation of the first control point, the elevation constraint, and the slope constraint; the slope constraint includes a fixed road slope between two adjacent control location points on the same target road.

12. An electronic device, wherein, The method includes a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the method according to any one of claims 1-10.

13. A computer program product comprising computer instructions, wherein, When executed by a processor, the computer instructions implement the method described in any one of claims 1-10.

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