Altitude difference drawing creation device

Abstract

To provide an altitude difference drawing creation device capable of creating an altitude difference drawing in which an altitude difference from the periphery of a road is expressed by considering a change of respective road altitude on both sides of the road.SOLUTION: Provided is an altitude difference drawing creation device characterized by comprising: a division unit 10 for dividing a road in map information into sections in the longitudinal direction; a stripe region setting unit 12 for setting a stripe region extending in the transverse direction of a target road in a section; a difference value calculation unit 14 for calculating, for each section, a difference value between the altitude value of a discretionary position in the stripe region and the altitude value of the target road in the section; and a display control unit 16 for displaying an altitude difference drawing in a manner corresponding to the calculated difference value.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an elevation difference map producing device. [Background technology]

[0002] In recent years, with the increase in torrential rains and the resulting increase in landslides, efforts are being made to use the results of airborne laser surveying to analyze slope disaster risks and identify dangerous slopes and streams that could cause damage to roads. In addition, there is a need to respond not only to slope disasters within road areas, but also to those adjacent to road areas and disasters that occur outside road areas.

[0003] In response to such requests, up until now, engineers have mainly used topographical data (microtopography-enhanced maps, slope classification maps, contour line data, etc.) to visually interpret elevation differences around roads and identify dangerous slopes and streams that could affect roads. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Administrative Notice dated September 29, 2006 (jointly signed by the Assistant Director of the National Highway and Disaster Prevention Division, the Assistant Director of the Road Disaster Prevention Measures Office, the Assistant Director of the Local Road and Environment Division, and the Assistant Director of the Toll Road Division, Road Bureau, Ministry of Land, Infrastructure, Transport and Tourism), Implementation Guidelines for "Reconfirmation of Disaster-Prone Areas on Roads" and Inspection Guidelines for Article 4 (2) [Non-Patent Document 2] Road Disaster Prevention Inspection Guide (Heavy Rain, Heavy Snow, etc.) [Revised Edition] - A Challenge for the Digital Transformation Era -, Japan Geological Survey Association, Road Disaster Prevention Inspection Technology Training Seminar Text, March 2022 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when determining whether a disaster will affect roads, the elevation difference that needs to be read is the relative elevation difference to the road, and because the elevation of the road itself changes along the road, visual reading required a great deal of effort. Furthermore, for roads with different elevations on the uphill and downhill sides, the elevation difference must be read by changing the reference elevation according to the route, which required even more effort.

[0006] Furthermore, when visually interpreting a wide area, such as the entirety of a specific region, the interpretation work must be done by a large number of people, and the results of extracting dangerous slopes and streams that could affect roads vary depending on the skills of the engineers. In addition, even when multiple engineers are involved, the interpretation work takes a long time.

[0007] An object of the present invention is to provide an elevation difference map creating device capable of creating an elevation difference map which represents the elevation difference between the road and its surroundings, taking into account the change in road elevation on both sides of the road. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention includes the following embodiments. [1] An elevation difference map creation device comprising: a division means for dividing roads in map information into sections in a longitudinal direction; a strip-shaped area setting means for setting strip-shaped areas in the sections extending in a transverse direction of the road; a difference value calculation means for calculating, for each section, a difference value between the elevation value of an arbitrary position in the strip-shaped area and the elevation value of the road in that section; and a display means for displaying map information in a manner corresponding to the difference value. [2] The elevation difference map creation device described in [1] is characterized in that the dividing means divides the road into sections for each lane, and the strip area setting means sets the strip area in one direction for each lane of the two transverse directions in the section. [3] The elevation difference map creation device according to [1] or [2], characterized in that the difference value calculation means calculates the difference value for each arbitrary position within the strip region. [4] The elevation difference map creation device according to [3], wherein the arbitrary position is a position of a unit area obtained by dividing the strip area at arbitrary intervals. [5] A method for creating an elevation difference map, comprising the steps of: dividing roads in map information into longitudinal sections; setting strip-shaped areas in the sections extending transversely of the roads; calculating, for each section, a difference value between the elevation value of any position in the strip-shaped area and the elevation value of the road within that section; and displaying map information in a manner corresponding to the difference value. [6] An elevation difference map creation program that causes a computer to function as: a division means for dividing roads in map information into longitudinal sections; a strip setting means for setting strips extending transversely of the roads within each section; a difference value calculation means for calculating, for each section, the difference value between the elevation value of any position within the strip and the elevation value of the road within that section; and a display means for displaying map information in a manner corresponding to the difference value. Effect of the Invention

[0009] According to the present invention, since it is possible to create an elevation difference map that takes into account changes in road elevation, it is possible to easily grasp the conditions for excluding dangerous slopes and streams that affect roads. As a result, screening becomes easier and the elevation difference between the road and its surroundings can be visually interpreted efficiently. [Brief description of the drawings]

[0010] [Figure 1] 1 is a functional block diagram of an example of an elevation difference map creating device according to an embodiment; [Diagram 2] 11A to 11C are explanatory diagrams of a strip-shaped region setting process according to an embodiment. [Diagram 3] FIG. 13 is a diagram showing a display example of an elevation difference map according to the embodiment. [Figure 4] FIG. 4 is a flow diagram of an operation example of the elevation difference map creating device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, modes for carrying out the present invention (hereinafter, referred to as embodiments) will be described with reference to the drawings.

[0012] 1 shows a functional block diagram of an example of an elevation difference map creation device 100 according to an embodiment. The elevation difference map creation device 100 includes a division unit 10, a band-shaped region setting unit 12, a difference value calculation unit 14, a display control unit 16, a storage unit 18, and a CPU 20, and is configured as a computer that controls the entire device and performs various calculations. The CPU 20 may include an accelerator such as a GPU in addition to the CPU.

[0013] The CPU 20 functions as the division unit 10, the strip setting unit 12, the difference value calculation unit 14, the display control unit 16, etc. Each of the above functions is realized by the CPU 20 and a program that controls the processing operation of the CPU 20, for example.

[0014] The dividing unit 10 generates a road centerline for a road (hereinafter, sometimes referred to as a target road) for which an elevation difference map is to be created, and divides the road centerline into sections of any distance, thereby dividing the target road into a plurality of sections in the longitudinal direction. The road centerline can be generated, for example, by displaying map information (map data) including the target road on a display device using the display control unit 16, sequentially specifying points on the centerline of the target road using an appropriate input means (a pointing device such as a mouse, a touch panel, etc.), and connecting or curve-approximating the specified plurality of points in the specified order. Alternatively, the road centerline generation process can be realized by executing a road centerline generation process using a conventionally known program for map data including the target road. In this case, it is preferable to read out and use a micro-topography-enhanced map or the like previously stored in the storage unit 18, and generate the road centerline for each uphill and downhill lane of the road on the map. The road centerline generation process may be an automatic process using a program, a semi-automatic process in which the automatic processing result is manually corrected, or a manual process in which the road centerline is manually generated while visually checking the micro-topography-enhanced map or the like. The micro-topography-enhanced map is generated by analyzing a digital elevation model (DEM) in advance using a known program. Instead of the micro-topography-enhanced map, the digital elevation model may be displayed or automatically processed to generate the road centerline. In addition, in the case of narrow roads, etc., if necessary, the road centerline may be generated in the center of the road without distinguishing between lanes.

[0015] The process of dividing the road centerline is executed by the dividing unit 10 by generating division points at intervals of any distance (for example, 1 m) for each up and down lane along the generated road centerline, and dividing the road centerline into sections sandwiched between two adjacent division points. In this case, the end points (start points or end points of division) of the division points to be generated may be set automatically by the dividing unit 10, or may be set manually by an appropriate input means.

[0016] Then, the division unit 10 generates a midpoint for every two adjacent division points. Next, the division unit 10 reads out from the storage unit 18 a digital elevation model including the target road and its surrounding area that has been stored in advance in the storage unit 18, and acquires the elevation value of the target road at each of the midpoints. The acquired elevation value is set as the elevation value of the target road in each of the divided sections to which each midpoint belongs.

[0017] The map information such as the micro-topography-enhanced map and the digital elevation model may be obtained from an external server or the like by an appropriate communication means and used. The division unit 10 stores the position information of the road centerline, division points, sections, and midpoints, as well as the elevation value information of the target road in the storage unit 18. The elevation value of the target road in each section may be, instead of the elevation value of the midpoint, a representative value (average value, maximum value, minimum value, or median value) of the elevation value on the road centerline in the section, a representative value of the elevation value in a circular area with a radius of 1 m centered on the midpoint, or a representative value of the elevation value in a rectangular area with a width that is preset to be equal to or less than the road width and perpendicular to the road centerline in the section. Although the road centerline is shown here as an example, the present invention is not necessarily limited to this. For example, instead of the road centerline, a road accessory that extends linearly in the longitudinal direction of the road, such as a road edge or a median strip, may be used.

[0018] The strip setting unit 12 reads out the map information and section information from the storage unit 18, and sets a strip (strip-shaped area) extending in the transverse direction of the target road in each section on a map including the target road, such as a micro-topography-enhanced map. Specifically, the strip setting unit 12 sets a strip extending in the horizontal direction of the target road in a direction perpendicular to the road center line in each section around the target road. Note that the transverse direction in a section where the road center line is not linear can be a direction perpendicular to the tangent to the road center line. In this case, the width of the strip is the length of the section (e.g., 1 m), and the transverse length of the target road can be set arbitrarily depending on the width of the surrounding range required to be interpreted, but may be set to, for example, 60 m from the road center line, taking into account the distance to structures around the road. In addition, when uphill and downhill lanes are set on the target road, the strip is set in one of the two transverse directions with respect to each lane, that is, on the left side of each lane in the traveling direction. The strip-shaped region setting unit 12 causes the storage unit 18 to store coordinate information (or shape information) for identifying the strip-shaped region set for each section in association with the section.

[0019] The difference value calculation unit 14 reads out from the storage unit 18 a digital elevation model (DEM) including the target road and its surrounding area, position information of the midpoint, and information on the strip area of ​​each section, and for each section, obtains an elevation value of an arbitrary position in each strip area from the digital elevation model (DEM), and calculates a difference value (elevation value of each section of the target road - elevation value of an arbitrary position in the strip area) between the elevation value of the target road in the section set in each strip area. Here, the arbitrary position in each strip area can be the position of a unit area obtained by dividing the strip area at an arbitrary interval. The arbitrary position in each strip area can be, for example, the position of a mesh included in the strip area among multiple meshes set in the digital elevation model, and the elevation value of the arbitrary position can be the elevation value of the mesh. Note that when one mesh is included in multiple strip areas, the position of the mesh may be the position of the unit area only for the strip area with the largest area of ​​the included mesh. Alternatively, the arbitrary position within each strip can be the position of a unit area obtained by dividing the strip in the transverse direction of the target road, for example, the position of the center point of the unit area in the transverse direction of the target road, within a unit area obtained by dividing the strip at arbitrary intervals (for example, 1 m). In these cases, the difference value is calculated for each unit area obtained by dividing the strip. As described above, the difference value is calculated using the altitude value set for each section, so that the altitude difference (difference value) with respect to the surroundings of the road can be calculated taking into account changes in the road altitude. The difference value calculation unit 14 stores this difference value in the memory unit 18.

[0020] The display control unit 16 controls a liquid crystal display device or other appropriate display device based on instructions from the division unit 10, the strip setting unit 12, and the difference value calculation unit 14 to display map information including the target road, road centerlines, sections and their midpoints, strip areas, an elevation difference map, etc. Here, the elevation difference map refers to map information including the target road displayed in a manner according to the difference value calculated by the difference value calculation unit 14. The manner according to the difference value refers to, for example, displaying different background colors or patterns according to sections arbitrarily determined according to the magnitude of the difference value.

[0021] The storage unit 18 is composed of a non-volatile memory such as a hard disk drive or a solid state drive (SSD), and stores information necessary for each process performed by the elevation difference map creation device 100, such as the above-mentioned data and a program for operating the CPU 20. Note that the storage unit 18 may be a digital versatile disk (DVD), a compact disk (CD), a magneto-optical disk (MO), a flexible disk (FD), a magnetic tape, an electrically erasable and rewritable read-only memory (EEPROM), a flash memory, or the like. It is preferable that the storage unit 18 includes a random access memory (RAM) that mainly functions as a working area for the CPU 20, and a read-only memory (ROM) in which control programs such as the BIOS and other data used by the CPU 20 are stored. Note that the storage unit 18 may include an external storage device.

[0022] An explanatory diagram of the process of setting a strip-shaped area is shown in Fig. 2. In Fig. 2, the target road R is a road, such as an expressway, on which an up-bound lane r1 and an down-bound lane r2 are set by a central reservation strip D. This target road R is displayed as map information including the target road on an appropriate display device by the display control unit 16.

[0023] The division unit 10 generates road centerlines C1 and C2 for the up line r1 and the down line r2 of the target road R, respectively. Next, the division unit 10 generates division points d1 and d2 at intervals of any distance (for example, 1 m horizontal distance. It may be 1 m in the direction along the road surface) along the road centerlines C1 and C2, respectively. In the example of FIG. 2, each division point d1 and d2 is indicated by a black circle (●). The road centerlines C1 and C2 are divided into sections of the above-mentioned any distance by adjacent division points d1 and d2, and the target road is divided into a plurality of sections in the longitudinal direction. In addition, the division unit 10 generates midpoints m1 and m2 between two adjacent division points d1 and d2. In the example of FIG. 2, each midpoint m1 and m2 is indicated by a cross (×). As described above, the elevation value of each midpoint m1 and m2 is set as the elevation value of each section.

[0024] The strip setting unit 12 sets strips b1, b2 that are perpendicular to the road center lines C1, C2 and extend horizontally on the target road R with the length of the section as a width in each section defined by adjacent division points d1 and d2. In this case, if the target road has an up line r1 and an down line r2, strips b1, b2 are set on the left side of each lane in the traveling direction. The lengths L1, L2 of the strips b1, b2 in the direction perpendicular to the road center lines C1, C2 (transverse direction of the target road R) can be set arbitrarily depending on the width of the surrounding range required to be interpreted, but can be set to, for example, 60 m in consideration of the distance to structures around the road. In this way, the strip setting unit 12 sets strips b1, b2 that extend in the transverse direction in each section of the target road R.

[0025] Furthermore, an arbitrary position in each strip area used by the difference value calculation unit 14 when calculating the difference value is obtained as a mesh set in the digital elevation model. Alternatively, an arbitrary position in each strip area used by the difference value calculation unit 14 when calculating the difference value is obtained as a point (for example, the center point of the area) in unit areas a1, a2 obtained by dividing the strip area in the transverse direction of the target road R as shown in FIG. 2.

[0026] FIG. 3 shows an example of the elevation difference map. It is preferable to set display conditions for the elevation difference map shown in FIG. 3 so that engineers can use it to understand the conditions for rockfall and collapse, the conditions for reaching the road, and the conditions for soil and sand to run up onto the road. Such display conditions are as follows: (A) For example, the slope conditions for rockfall and collapse described in the inspection guidelines in Non-Patent Document 1 are a slope angle of 45 degrees or more or a slope height of 15 m or more. (B) It is preferable to determine the conditions for the arrival of collapsed soil and sand on the road, as described in the manual for basic surveys based on the Landslide Disaster Prevention Law, taking into consideration the view that even if the above slope conditions are met, soil and sand will not reach the road if the relative height from the opposite bank is 5 m or more, in other words, even if a slope collapse occurs, the resulting soil and sand will not affect the road if the relative height from the road is 5 m or more (exclusion condition).

[0027] In the example of FIG. 3, a target road R on which an up-bound lane r1 and an down-bound lane r2 are set by a central reservation strip D is shown together with a topographical map of the surrounding area, and strip areas b1 and b2 are set on the left side of each lane in the traveling direction. Also, in the example of FIG. 3, the difference value calculation unit 14 calculates a difference value for each mesh of the digital elevation model that overlaps with the strip areas b1 and b2. Also, in the example of FIG. 3, the difference value calculated by the difference value calculation unit 14 (elevation value of the target road (road surface) - elevation value of any position (ground) within the strip area) is color-coded according to the difference value, which is the above condition (B) of less than 5 m and 5 m or more. Also, for the above condition (A), the relevant area is displayed by hatching and a black frame. The engineers performing the interpretation work will make a comprehensive judgment on the impact on the road, taking into consideration the conditions under which rockfalls and collapses will occur (slope condition (A) above), the condition under which collapsed soil and other materials will reach the road - "the distance twice the slope height (maximum 50m) > the distance from the toe of the slope to the road" (examples of rockfalls and rock collapses), as well as the above condition (B).

[0028] FIG. 4 shows a flow diagram of an operation example of the elevation difference map creation device 100 according to the embodiment. In FIG. 4, the division unit 10 generates a road centerline for a target road in map information (S1). In this case, it is preferable to generate a road centerline for each uphill and downhill lane. The division unit 10 generates division points at intervals of any distance along the generated road centerline, and divides the road centerline into sections sandwiched between two adjacent division points, thereby dividing the target road into a plurality of sections in the longitudinal direction (S2). After that, the division unit 10 generates a midpoint of each section for each adjacent two division points (S3).

[0029] Next, the division unit 10 uses a digital elevation model (DEM) including the target road and its surrounding area to obtain the elevation value of the target road at each of the midpoints (S4), and sets these as the elevation value of each section to which each midpoint belongs (S5).

[0030] The strip setting unit 12 sets a strip in each section on the map including the target road, the strip extending in a direction perpendicular to the road centerline and transverse to the target road (S6). The strip setting unit 12 sets the elevation value of the section set in S5 for each strip (S7).

[0031] The difference value calculation unit 14 uses a digital elevation model (DEM) including the target road and its surrounding area, acquires the elevation value of the point from the digital elevation model (DEM) at any interval in each strip, and calculates a difference value between the elevation value of the arbitrary position in the strip and the elevation value in the above-mentioned section set in each strip (S8) by using the elevation value of the arbitrary position in the strip. Note that, as described above, the elevation value of the mesh included in each strip may be used as the elevation value of the arbitrary position.

[0032] The display control unit 16 displays an elevation difference map or the like, which is map information including the target road displayed in a manner according to the difference value calculated by the difference value calculation unit 14 (S9).

[0033] The program for executing each step in Fig. 4 may be stored in a recording medium, or the program may be provided by a communication means. In that case, for example, the above-described program may be regarded as an invention of a "computer-readable recording medium on which a program is recorded" or an invention of a "data signal." [Explanation of symbols]

[0034] 10 division unit, 12 band-shaped region setting unit, 14 difference value calculation unit, 16 display control unit, 18 storage unit, 20 CPU, 100 elevation difference map creation device.

Claims

1. A dividing means for dividing a road in the map information into sections in a longitudinal direction; a strip-shaped area setting means for setting a strip-shaped area extending in a transverse direction of the road in the section; a difference value calculation means for calculating, for each section, a difference value between an elevation value of an arbitrary position within the strip area and an elevation value of the road within the section; a display means for displaying map information in a manner corresponding to the difference value; An elevation difference map creating device comprising:

2. The dividing means divides the road into the sections for each lane, 2. The elevation difference map creating device according to claim 1, wherein the belt-like area setting means sets the belt-like area in one of the two transverse directions in the section for each lane.

3. 3. An elevation difference map producing device according to claim 1, wherein the difference value calculation means calculates the difference value for each arbitrary position within the band-like region.

4. 4. The elevation difference map producing device according to claim 3, wherein the arbitrary positions are positions of unit areas obtained by dividing the strip area at arbitrary intervals.

5. Dividing roads in the map information into sections in a longitudinal direction; setting a strip-shaped area in the section extending in a transverse direction of the road; calculating, for each section, a difference value between an elevation value of an arbitrary position within the strip area and an elevation value of the road within the section; displaying map information in a manner corresponding to the difference value; 1. A method for creating an elevation difference map, comprising:

6. Computer, a dividing means for dividing a road in the map information into sections in a longitudinal direction; a strip-shaped area setting means for setting a strip-shaped area extending in a transverse direction of the road in the section; a difference value calculation means for calculating, for each section, a difference value between an elevation value of an arbitrary position within the strip area and an elevation value of the road within the section; a display means for displaying map information in a manner corresponding to the difference value; 4. An elevation difference map creation program comprising:

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