System, method and program for road surface state analysis

Abstract

To provide a technique for analyzing whether or not a road surface is travelable, in accordance with a situation of a traveling person traveling on the road surface.SOLUTION: A road surface state analysis system includes: an input unit for inputting operation plane space information required for a traveling person traveling on a road surface to move, and height information and depth information of a step that the traveling person can get over; an extraction unit for extracting a plurality of travelable areas each having a width of the operation plane space information or more, and non-travelable areas, from three-dimensional map data of the road surface; a setting unit for setting the non-travelable areas each sandwiched between each two of the travelable areas, as a step area; a determination unit for determining whether or not the traveling person can get over the step area, on the basis of the height information and depth information of the step; and an update unit for updating the step areas determined to be possible to get over, from the non-travelable area to a get over enabled area.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE The present invention relates to a technique for analyzing a road surface condition. [Background technology]

[0002] Technology that automatically extracts areas where a subject can move from map data of spatial environments, such as 3D maps generated by drone surveying, is being researched in fields such as autonomous driving. If such technology can be used to extract areas where a wheelchair can move, it can be used as environmental information such as evacuation routes in the event of a disaster. On the other hand, wheelchairs have unique difficulties when going over steps. For example, they need to face forward when going up steps and backward when going down steps.

[0003] For this reason, wheelchairs cannot get over steps with a narrow protrusion (for example, a step with a single curbstone separating the roadway from the sidewalk). On the other hand, wheelchairs can get over steps with a wide protrusion if there is enough space for the wheelchair to turn around after going up the step.

[0004] Patent Document 1 discloses a technology that checks driving route information extracted from 3D map data against vehicle body information of an automated guided vehicle to determine a drivable driving route, and sets an optimal route from a starting point to a destination point from the driving route mapped on the 3D map. The driving route is determined based on four conditions: passing, turning, steps, and climbing. For example, if the route is narrower than the vehicle body dimensions, it is determined that passing is not possible, if the curve is sharper than the minimum turning radius of the vehicle, it is determined that turning is not possible, if the step is higher than the maximum step that can be traversed, it is determined that it is not possible to overcome, and if the slope is even steeper, it is determined that it is not possible to overcome. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6605232 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in Patent Document 1, the criteria for determining whether or not a wheelchair can be overcome are only the height and gradient of the obstacle, and the minimum turning radius of the vehicle is not used. As a result, it is not possible to determine whether there is enough space for the wheelchair to turn around after climbing up the step, and there is a problem in that it is not possible to accurately analyze road surface conditions that allow wheelchairs to travel on them.

[0007] The present invention was completed through extensive research focusing on these issues, and its purpose is to provide technology for analyzing whether a road surface is suitable for driving depending on the situation of drivers driving on that road surface. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides a road surface condition analysis system comprising: an input unit that inputs operational plane space information necessary for a runner to move along a road surface, and height information and depth information of a step that the runner can overcome; an extraction unit that extracts a plurality of drivable areas and non-drivable areas that are larger than or equal to the operational plane space information from three-dimensional map data of the road surface; a setting unit that sets the non-drivable area sandwiched between two of the drivable areas as a step area; a determination unit that determines whether the runner can overcome the step area based on the height information and depth information of the step; and an update unit that updates the step area that is determined to be drivable from the non-drivable area to a drivable area.

[0009] Another invention is a road surface condition analysis method comprising: an input step of inputting operational plane space information necessary for a runner to move along a road surface, and height information and depth information of a step that the runner can overcome; an extraction step of extracting a plurality of drivable areas and non-drivable areas that are larger than or equal to the operational plane space information from three-dimensional map data of the road surface; a setting step of setting the non-drivable area sandwiched between two of the drivable areas as a step area; a determination step of determining whether the runner can overcome the step area based on the height information and depth information of the step; and an update step of updating the step area determined to be drivable from the non-drivable area to a drivable area.

[0010] Another invention is a road surface condition analysis program executable by a computer, comprising: an input step of inputting operational plane space information necessary for a runner to move along a road surface, and height information and depth information of a step that the runner can overcome; an extraction step of extracting a plurality of drivable areas and non-drivable areas that are larger than or equal to the operational plane space information from three-dimensional map data of the road surface; a setting step of setting the non-drivable area sandwiched between two of the drivable areas as a step area; a determination step of determining whether the runner can overcome the step area based on the height information and depth information of the step; and an update step of updating the step area determined to be drivable from the non-drivable area to a drivable area. Effect of the Invention

[0011] According to the present invention, it is possible to provide a technique for analyzing whether or not a road surface is passable depending on the situation of a runner running on the road surface. [Brief description of the drawings]

[0012] [Figure 1] 1 is a functional block diagram of a road surface condition analyzing system according to an embodiment of the present invention. [Diagram 2]FIG. 13 is a diagram for explaining an example of climbing over a step (wheelchair with an assistant) according to the present embodiment. [Diagram 3] 10A and 10B are diagrams for explaining extraction of a travelable area and determination of whether or not a step will be overcome according to the present embodiment. [Figure 4] FIG. 11 is a diagram showing a condition for determining whether a step can be climbed over according to the present embodiment. [Diagram 5] 4 is a flowchart relating to extraction of a driveable area and setting of a passable area according to the present embodiment. [Figure 6] FIG. 4 is a diagram showing an example of extraction of a travelable area according to the present embodiment; [Figure 7] FIG. 11 is a diagram showing a first example of setting a jump-over area according to the present embodiment. [Figure 8] FIG. 11 is a diagram showing a second example of setting a jump-over area according to the present embodiment. [Figure 9] FIG. 11 is a diagram showing a third example of setting a jump-over area according to the present embodiment. [Figure 10] FIG. 2 is a diagram showing an example of a road surface environment to be analyzed; [Figure 11] 11A to 11C are diagrams showing the results of analysis of the road surface for each runner by the road surface condition analysis system according to the present embodiment. [Figure 12] FIG. 11 is a diagram showing an example of the shortest route calculated for each runner from a map generated by the present invention according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An embodiment of the present invention will be described with reference to the drawings. In this embodiment, the drivable area refers to a flat area on a flat road surface that is at least as large as the runner's size on a plane. In addition, the non-drivable area refers to steps on the road surface that cannot be overcome (including obstacles with unclear external shapes), but the steps that can be overcome vary depending on the runner. For example, for a wheelchair user, a flat area that is at least as large as the size of the wheelchair body (the body's minimum turning diameter) corresponds to a drivable area, while a step 40 cm or higher corresponds to an impassable area.

[0014] (Road surface condition analysis system) 1 is a functional block diagram of a road surface condition analysis system according to an embodiment of the present invention. The road surface condition analysis system 100 uses 3D map data of the road surface provided from a 3D map database 200 to determine whether a runner traveling on the road surface can overcome a step depending on the situation, and extracts a drivable area. Here, the runner may be anyone who moves on the road surface, and there is no restriction on the means of transportation, and may be an ordinary pedestrian or a wheelchair user with a caregiver.

[0015] The three-dimensional map database 200 stores three-dimensional map data related to the spatial environment of various regions. The three-dimensional map data is generated, for example, by an aerial laser surveying method using a drone. In the aerial laser surveying method, for example, a drone is raised to an altitude of about 50 m in the sky, an area of ​​about 70 m square is measured by a laser distance sensor, and the measured data is superimposed to generate a map. The three-dimensional map database 200 may be included in the road surface condition analysis system 100. In addition, the road surface condition analysis system 100 may use an external three-dimensional map database 200 via the Internet. In addition, the road surface condition analysis system 100 may use three-dimensional shape data of the environment measured in real time by a sensor installed on the runner as the three-dimensional map data.

[0016] The road surface condition analysis system 100 of this embodiment is configured as road surface condition analysis software that can run on a computer that can transmit and receive data via the Internet. The road surface condition analysis system 100 downloads 3D map data related to the road surface environment around the runner from an external 3D map database 200, and extracts a drivable area according to the runner from the 3D map data.

[0017] The road surface condition analysis system 100 includes an input unit 110 that receives input of motion plane space information required for a runner to move on a road surface, height information and depth information of a step that the runner can overcome, an extraction unit 120 that extracts a plurality of drivable areas and non-drivable areas that are larger than the motion plane space information from 3D map data of the road surface, a setting unit 130 that sets an non-drivable area sandwiched between two drivable areas as a step area, a determination unit 140 that determines whether the runner can overcome the step area based on the step height information and depth information, and an update unit 150 that updates the step area determined to be drivable from the non-drivable area to a drivable area. The road surface condition analysis system 100 can be implemented by implementing each functional block of such road surface condition analysis software in an executable form on a computer such as a virtual server provided by a cloud service provider.

[0018] (Criteria for determining whether a step can be overcome) In this embodiment, a wheelchair with a caregiver (hereinafter, simply referred to as a wheelchair) is taken as an example of a runner traveling on a road surface. It is also assumed that there is only one caregiver. The conditions for determining whether a step can be overcome by a wheelchair will be described.

[0019] Using Figure 2, we will explain whether a wheelchair can overcome a step by dividing it into several cases. Here, we will explain the cases of (1) going up a simple step, (2) going up a series of steps, (3) going over a convex step, and (4) going over a concave step. In all cases, we will assume that there is a vehicle width (approximately 90 cm) wide enough for a wheelchair to pass through.

[0020] (1) The case of climbing a simple step will be explained depending on the height of the step. When the step is about 20 cm high, the caregiver pushes down the handle at the rear of the wheelchair, lifts the front wheels of the wheelchair, moves the wheelchair forward, and places the front wheels on the step. The caregiver then lifts the handle up, and with the rear wheels of the wheelchair raised, moves further forward, so that the rear wheels of the wheelchair also place on the step. In this way, the wheelchair is able to get over the step. On the other hand, when the height of a step is about 40 cm, it is not even possible to place the front wheels of the wheelchair on the step, making it impossible to get over the step.

[0021] (2) The case of going up successive steps will be explained based on the width of the first step. It is assumed that the width of the vehicle is sufficient, so width here refers to depth. If the first step is deep enough for the entire wheelchair to remain on it, it can go over the first step (20 cm high) and then the second step (20 cm high). On the other hand, if the first step is not deep enough for the entire wheelchair to remain on it, only the front wheels of the wheelchair can go up the first step. In this condition, the wheelchair cannot get over with one caregiver.

[0022] (3) Regarding going over a convex step, we will explain this based on the width of the upper part of the convex step. The wheelchair needs to face forward when going up the step, and backward when going down the step. The reason for turning in this way is that wheelchairs for assistance do not generally have seat belts. A space of about 150 cm in diameter is required for the wheelchair to turn 180 degrees and turn.

[0023] If the diameter of the convex top is about 150cm, the wheelchair can climb up to the top of the step facing forward, turn 180 degrees, turn backwards and then climb down the step. On the other hand, if the diameter of the convex top is less than 150cm and the wheelchair cannot rotate 180 degrees at the convex top, it cannot climb over the step.

[0024] (4) The case of going over a concave step will be explained depending on the width of the concave lower part. If the width of the concave lower part is about 150 cm in diameter, the wheelchair must rotate 180 degrees before descending the step, facing backwards, and then descend the step. It must then rotate 180 degrees again, facing forwards, and be able to go over the step. On the other hand, if the width of the convex lower part is less than 150 cm in diameter and the wheelchair cannot rotate 180 degrees at the convex lower part, it will not be able to go over.

[0025] In addition, if the concave step is deep, it is not possible to determine whether the step can be overcome simply based on the height of the step. For example, if the depth of the depression is narrow and shorter than the distance between the front and rear wheels of a wheelchair, it is possible to overcome the depression by first lifting the front wheel, then landing the front wheel, and then lifting the rear wheel.

[0026] Extraction of the driveable area and determination of whether the step can be overcome will be described with reference to Fig. 3. In this embodiment, a flat road surface the size of the vehicle body is set as the driveable area, and steps are further separated from the driveable area, which simplifies the method of determining whether the step can be overcome.

[0027] When a runner is in a wheelchair, the drivable area is set by considering the size of the wheelchair body as well as the road surface being flat. In the case of a wheelchair, for example, a road surface that not only has the planar dimensions of the body (length in the direction of travel and width) but also has a range in which the wheelchair can turn (diameter of about 150 cm) is set as the drivable area. The range in which the wheelchair can turn (diameter of about 150 cm) can also be defined as the planar motion space information required for the runner to move on the road surface.

[0028] Using FIG. 1(a), we will explain how to extract a drivable area. Two types of steps are given as examples here. The example on the left has two steps, but all three road surfaces are extracted as areas where a wheelchair can be driven (three double-headed arrow lines). On the other hand, the example on the right also has two steps, but the middle road surface is extracted as an undriveable area where a wheelchair cannot drive, and only the bottom and top road surfaces are extracted as areas where a wheelchair can be driven (two double-headed arrow lines).

[0029] Using FIG. 1(b), we will explain how to determine that the space between drivable areas is one step. In the case of the left side, the height of the two steps is 20 cm. As mentioned above, a wheelchair with an attendant can overcome a step of 20 cm in height. And, since the road surface on both sides of both steps is within the drivable area, it is possible to overcome both steps.

[0030] In the case of the right side, the height of the two steps is also 20 cm. However, the road surface in the middle is an undriveable area, while the bottom and top road surfaces are driveable areas (two double-headed arrow lines). Therefore, the area between the two driveable areas at the bottom and top (between the two double-headed arrow lines) is determined to be one step. In this case, the two 20 cm steps are set as one 40 cm step, and it is determined that a wheelchair with an attendant cannot get over it. By setting the undriveable area sandwiched between the two driveable areas as a step area in this way, it becomes possible to easily determine that the example on the left can be got over, but the example on the right cannot.

[0031] FIG. 4 shows the conditions for determining whether a step can be overcome according to this embodiment. In this embodiment, if all of the following four conditions (A) to (D) are met, it is determined that the step can be overcome. Here, the specific numerical values ​​of the conditions are taken as an example for a wheelchair. Note that the steps are shown in a cloud shape in order to include obstacles with unclear external shapes, and also because it is assumed that it may be difficult to distinguish whether the rise of the step is steep or gradual depending on the pixel accuracy of the 3D map data.

[0032] Condition (A) is that there must be a drivable area before and after the step. The two double-arrowed lines in Figure 4 correspond to the drivable areas before and after the step. Considering that both drivable areas are flat road surfaces including a circle with a radius of 75 cm, the length of both drivable areas is set to be 150 cm or more.

[0033] Condition (B) is that the depth information of the step is equal to or less than a threshold value. For example, if the concave step in Figure 2 is a deep depression, the depth information of the step must be equal to or less than a threshold value. Here, the depth information of the step is set to 10 cm or less. Note that condition (B) is also set to reduce noise in the sensor data measured by the drone; for example, in the case of a step that rises vertically, the depth information of the step is 0 cm.

[0034] Condition (C) is that the step height information as seen from the lower road surface is equal to or less than a threshold value. Here, taking into consideration that the caregiver will climb over the step with the front and rear wheels of the wheelchair separately, the step height information as seen from the lower road surface is set to 20 cm or less.

[0035] Condition (D) is that the step height information as seen from the higher road surface is equal to or less than a threshold. Considering that wheelchairs for assistance generally do not have seat belts, the step height information as seen from the higher road surface is set to 5 cm or less. Condition (D), like condition (B), is also set to reduce noise in the sensor data measured by the drone. Note that hereinafter, the step height information as seen from the lower road surface and the step height information as seen from the higher road surface are collectively referred to simply as step height information. Note that in the case of a deep depression, which is described as a concave step in Figure 2, the step heights in conditions (C) and (D) are values ​​less than 0 cm. Therefore, in the case of a deep depression, conditions (C) and (D) are automatically met, and whether or not the depression can be overcome is determined only by conditions (A) and (B).

[0036] (Flowchart for extracting drivable areas and determining surmountable steps) Fig. 5 is a flowchart relating to the process of extracting a driveable area and the process of setting a passable area according to this embodiment. S110 and S120 relate to the process of extracting a driveable area, and S130 to S190 relate to the process of setting a passable area. Figs. 6 to 9 are specific examples for explaining the flowchart. Fig. 6 shows an example of extracting a driveable area according to this embodiment.

[0037] 7 to 9 show examples (No. 1 to No. 3) of jump-over area settings according to this embodiment. FIG. 7 shows setting example No. 1 divided into three cases of angle θ, as described later, with the case of θ1 being denoted as (ai), the case of θ2 being denoted as (bi), and the case of θ3 being denoted as (ci). FIG. 8 shows setting No. 2 divided into cases of θ2 and θ3, as described later, with the case of θ2 being denoted as (b-ii) and the case of θ3 being denoted as (c-ii). FIG. 9 shows setting No. 3 for the case of θ2, as described later, with the case of θ2 being denoted as (b-iii).

[0038] First, the extraction process of the drivable area will be described. The input unit 110 of the road surface condition analysis system 100 accepts input of regional information of the road surface that the runner (here, a wheelchair user with an assistant) wishes to analyze, the runner's motion planar space information (a circle with a diameter of 150 cm as the size of the wheelchair body), height information of the step that the runner can overcome (step height information as seen from the lower road surface is 20 cm or less, and step height information as seen from the higher road surface is 5 cm or less), and depth information (10 cm or less). The extraction unit 120 receives the regional information of the road surface, the motion planar space information, and the height information and depth information of the step. The extraction unit 120 accesses the 3D map database 200 and acquires 3D map data of the road surface to be analyzed based on the regional information of the road surface. The extraction unit 120 classifies the acquired 3D map data into flat road surface areas and other areas (areas with steps, obstacles, etc.) (S110). Fig. 6(A) shows a portion of the map data after the classification process in S110. The map data is composed of pixel data. Steps, obstacles, and flat road surfaces are identified with solid lines. Please note that Fig. 6(A) looks like two-dimensional map data in terms of the way it is depicted in the drawing, but in fact it contains height information for steps, obstacles, etc.

[0039] The extraction unit 120 extracts a drivable area and an undrivable area from the map data of FIG. 6(A) (S120). Areas such as steps and obstacles are set as initial undrivable areas. Then, in order to reduce the amount of calculations by the computer, the size of the vehicle body is expressed as "one point" and a process is constructed to determine whether or not the area is drivable. Therefore, the outer edge (solid line) of the initial undrivable area is expanded by the amount of the motion plane space information (half the size of the body of the wheelchair). Specifically, the solid line is expanded in the normal direction by 75 cm, which is half of 150 cm. FIG. 6(B) shows the map data after expansion, where the outside of the dotted line is the drivable area and the inside is the expanded undrivable area. FIG. 6(B) can also be called a configuration space, and the vehicle body can be expressed as a point. FIG. 6 shows an example in which the drivable area and the undrivable area of ​​the road surface are extracted one by one, but the actual extraction unit 120 extracts multiple drivable areas and undrivable areas of the road surface.

[0040] Next, the process of setting the passable area will be described. The setting unit 130, the determination unit 140, and the update unit 150 of the road surface condition analysis system 100 cooperate to execute the process of determining the passable area from S130 to S190.

[0041] The setting unit 130 selects a point P on the boundary between the driveable area and the non-driveable area (the dotted line in FIG. 7) in pixel units of the map data (S130), and further selects a crossing angle θ for the driver to cross the non-driveable area, which is equal to or greater than 0° and less than 360° (S140). FIG 7 shows a case where the reference (0°) of the angle θ at point P is set to the horizontal line on the paper, and three angles (θ1, θ2, θ3) are selected.

[0042] The setting unit 130 draws a line from point P in the θ direction to another point on the boundary line (S150). The judgment unit 140 judges whether the length of the drawn line (line segment) is shorter than the depth information of the surmountable step (S160). The "depth information of the surmountable step" here is distance information obtained by adding the size of the vehicle body to the depth information of the step (B) shown in FIG. 4, and corresponds to the distance between the centers of the two travelable areas before and after the step (A) in FIG. 4 (the sum of the two radii of 75 cm plus the step depth). In the case of a wheelchair, the distance is 160 cm, which is obtained by adding the threshold value of the step depth of 10 cm to the distance of 150 cm. In (ai), (bi), and (ci) in FIG. 7, circles with a radius of 160 cm are drawn by two-dot chain lines with point P as the center. In this way, S160 is able to judge the conditions (A) and (B) in FIG. 4. Here, the outer edge of the initial undriveable area (solid line) is expanded to twice the size of half the vehicle body (75 cm) (see dotted line). Therefore, if the depth of the step area on the expanded map is less than the "depth information of a surmountable step", it means that the "step depth" on the original map is less than the "step depth threshold (10 cm)".

[0043] If the answer is Yes (i.e., it is short), the process proceeds to the next step (S170). On the other hand, if the answer is No (i.e., it is long), it is determined that the obstacle cannot be overcome, and the setting unit 130 is instructed to set an angle θ or point P that has not yet been determined.

[0044] In the case of Figure 7, (ai) represents the case of point P and angle θ1, where the dashed line segment crosses the dashed two-dot circle, so it is determined that it is not possible to get over. (bi) represents the case of point P and angle θ2, where the dashed line segment does not cross the dashed two-dot circle, so it moves to the next step. (ci) represents the case of point P and angle θ3, where the dashed line segment does not cross the dashed two-dot circle, so it moves to the next step.

[0045] The determination unit 140 analyzes the area through which the runner (wheelchair body) passes along the line segment when passing over (S170). The area through which the body passes is represented by a rectangle (dashed line in FIG. 8). One side of the rectangle (the direction of travel of the body) has the same length as the line segment, and the midpoint of the other side (the width direction of the body) intersects with the line segment at a right angle. In other words, point P corresponds to the center position of the body when the passing starts. The length of the other side may be the width of the body, 90 cm, but in this embodiment, all values ​​related to the size of the body are set to 150 cm to simplify the calculation process.

[0046] In the case of FIG. 8, (b-ii) represents the next step (S170) of FIG. 7(bi), and (c-ii) represents the next step (S170) of FIG. 7(ci). In both cases of (b-ii) and (c-ii), both conditions (C) and (D) of FIG. 4 are judged. If it is analyzed that both conditions (C) and (D) are satisfied, it corresponds to "possible to climb over" in S170, and proceeds to the next step. On the other hand, if neither is satisfied, it is judged that "not possible to climb over" in S170. Note that in this embodiment, in S170, whether or not it is possible to climb over is judged based on conditions (C) and (D) of FIG. 4, but other conditions (for example, whether the wheelchair is at a recommended approach angle for the step, or more specifically, whether the wheelchair is facing forward with respect to the steep step) may be added.

[0047] If FIG. 8(b-ii) is a case where both conditions (C) and (D) are satisfied, then this corresponds to S170's "possible to cross" and the process moves to the next step. If FIG. 8(c-ii) is a case where neither conditions (C) nor (D) are satisfied (for example, the step in the initial impassable area is too high), then it is determined that crossing is impossible. The star marks in FIG. 8 indicate the locations where the step is too high in the area surrounded by the solid line (initial impassable area). The vehicle body passing area in FIG. 8(b-ii) is away from the position of the star marks. On the other hand, the vehicle body passing area in FIG. 8(c-ii) includes the position of the star marks. For this reason, FIG. 8(c-ii) is determined to be impossible to cross.

[0048] If it is determined in S170 that the line segment is crossable, the update unit 150 sets the area on the corresponding line segment as a crossable area (S180). (b-iii) in Fig. 9 shows the next step (S180) of (b-ii) in Fig. 8. Then, the map data in the area on the line segment (the line segment in the θ2 direction from point P) is set as a crossable area in pixel units (see the dotted line area in Fig. 9).

[0049] The update unit 150 checks whether step determination has been performed for all angles θ of all points P (S190). That is, for all points P on the boundary line (dotted line in FIG. 9) between the travelable area and the non-travelable area, the step determination for angles θ of 0° or more and less than 360° is checked. If No, the process returns to S130 or S140. On the other hand, if Yes, the process in FIG. 5 ends. In this way, the update unit 150 can update a step area that has been determined to be traversable from an non-travelable area to a traversable area.

[0050] When the map (FIG. 6(A)) generated in S110 is used to determine condition (A) in FIG. 4, it is necessary to check whether or not there is a "flat road surface including a circle with a diameter of 150 cm" that is a drivable area before and after the step for all the jumping start positions around the area of ​​the step, obstacle, etc., and the jumping angle θ. However, when the map (FIG. 6(B)) generated in S120 is used, it is only necessary to determine whether or not there is a "point" that is a drivable area before and after the step. This is because, as explained in the process of S120, by expanding the outer edge (solid line) of the initially set non-drivable area by the amount of the operation plane space information (half the size of the wheelchair body), it becomes possible to determine whether or not the area is drivable without considering the size of the body (if there is even one point of the drivable area, it means that there is a "flat road surface including a circle with a diameter of 150 cm" there). In fact, as described above, in steps S150 and S160 for determining condition (A), it is only confirmed that there is a "point" that is a drivable area before and after the step. In this way, it is possible to reduce the load of the process of determining whether a step can be overcome.

[0051] When the process of Fig. 5 is completed, the road surface condition analysis system 100 outputs the map data including the updated crossover area. By displaying the map data on an external display or the like, the analyst can view the map data that has been analyzed to determine whether the road surface is drivable or not depending on the driver's situation.

[0052] (Example of application to disaster information) An example of applying the road surface condition analysis system 100 to disaster information will be described. FIG. 10 shows an example of a road surface environment to be analyzed, and shows a number of buildings constructed on a flat road surface as viewed from diagonally above right. The figure shows a road surface environment in which a disaster has occurred and a number of obstacles (hereinafter referred to as steps) of different shapes are placed between four buildings (A, B, C, and D). In an example in which a runner at a start point (e.g., an apartment building where people in various situations live) on the front side of the page wishes to evacuate to a goal point (e.g., a public evacuation shelter) on the back side of the page, the road surface condition analysis system 100 analyzes whether the runner can overcome the multiple steps according to the runner.

[0053] There is a high step between buildings A and B. There is a low convex step between buildings B and C. There is a low step between buildings C and D, and there is space above this low step for a wheelchair.

[0054] The system analyzes whether a runner on a road surface can overcome a step for four cases: a normal pedestrian, a stroller user, a wheelchair user (without a caregiver), and a wheelchair user (with a caregiver). In the road surface condition analysis system 100, the input unit 110 first receives input of motion plane space information required for each runner to move, and height information and depth information of steps that the runner can overcome.

[0055] In the case of a wheelchair user (with an assistant), the motion planar space information and the height and depth information of the step that can be overcome have been explained using Fig. 4. In the case of a wheelchair user (without an assistant), the height information of the step as seen from the lower road surface will be much lower than 20 cm, for example, 5 cm or less. On the other hand, the low step between building C and building D is set to 10 cm.

[0056] 5, the processing results from S110 to S160 are the same for both a wheelchair user (without an assistant) and a wheelchair user (with an assistant) regarding the low step between buildings C and D. However, the processing results at S170 are different, and it is analyzed that the wheelchair user (with an assistant) can get over the low step between buildings C and D, but the wheelchair user (without an assistant) cannot get over it.

[0057] Because stroller users do not need to turn around when going down a step, condition (D) in FIG. 4 can be set higher than for wheelchair users. Here, it is set between the height of the high step between buildings A and B and the height of the low, convex step between buildings B and C. As a result, the flowchart in FIG. 5 determines that stroller users cannot get over the high step between buildings A and B, but can get over the low step between buildings B and C.

[0058] All of the conditions in Fig. 4 are set to the extent that the pedestrian can overcome all of the steps in Fig. 10. Therefore, the flowchart in Fig. 5 determines that the pedestrian can overcome all of the steps in Fig. 10.

[0059] Fig. 11 shows the results of road surface analysis for each runner by the road surface analysis system 100. The road surface condition analysis system 100 analyzes whether each runner can overcome the steps in Fig. 10 according to the flowchart in Fig. 5. In Fig. 11, the steps that can be overcome are colored with a dotted line pattern, and the steps that cannot be overcome are colored black.

[0060] Figure 11(a) shows that pedestrians can overcome all steps. Figure 11(b) shows that stroller users can overcome all steps except those between buildings A and B. Figure 11(c) shows that wheelchair users (without a caregiver) cannot overcome any steps. Figure 11(d) shows that wheelchair users (with a caregiver) can overcome only the steps between buildings C and D.

[0061] FIG. 12 shows an example of the shortest route calculated for each runner from the map generated by the present invention according to this embodiment. The map data (FIGS. 11(a)-(d)) that is the analysis result of the road surface condition analysis system 100 can be applied to existing route search systems. Existing route search systems simply receive the map data of FIG. 11(a)-(d) and search for the shortest route from the start point to the goal point. FIG. 12(a)-(d) show the results of searching for the shortest route from the start point to the goal point for each runner with dotted arrows. Existing route search systems can easily search for the optimal route for each runner by using FIG. 11(a)-(d).

[0062] Therefore, if local governments can obtain 3D map data captured immediately after a disaster occurs, they can have the road surface condition analysis system 100 create map data for each pedestrian (Figures 11(a) to (d)). By then using an existing route search system, they can create evacuation maps for the disaster-stricken urban area for each pedestrian, enabling them to quickly plan evacuation routes for each pedestrian.

[0063] (Action and effect) According to the road surface condition analysis system 100 of this embodiment, it is possible to analyze whether or not the road surface is suitable for driving depending on the situation of the runner driving on the road surface (for example, if the runner is in a wheelchair, whether or not he or she is accompanied by an assistant).

[0064] In this embodiment, only points on the boundary between the passable area and the non-passable area are targeted in S130 and S150, which are part of the step group for determining whether or not the step can be overcome. A modified example will be described in which the points are not limited to the boundary, but all points included in the non-passable area are targeted for investigation.

[0065] (Modification) For each pixel point included in the non-driveable area set in S120, the following procedure is used to determine whether the step can be overcome: (a) A line is drawn from the relevant point at an angle θ until both ends reach the driveable area, and the length of the drawn line (line segment) is calculated. (b) If the length is less than a predetermined threshold, the height of the step at all points in the vehicle body passing area when passing along the line segment is checked. (c) If the height at all points in the vehicle body passing area is less than a predetermined threshold, all pixels on the line segment in (a) are determined to be able to be passed over. (d) The steps (a) to (c) are scanned for the relevant point until the angle θ changes from 0° to 360°.

[0066] Although the embodiments (including modified examples) of the present invention have been described above, two or more of these embodiments may be combined and implemented. Alternatively, one of these embodiments may be partially implemented. Furthermore, two or more of these embodiments may be partially combined and implemented. For example, the motion plane space information is defined as the size information of the runner on a plane, but is not limited to this, and may further include width information required for the runner to pass. In the case of a wheelchair user, the size information of the runner on a plane may be input to the input unit 110 as a diameter of 150 cm, and the width information required for the runner to pass may be input as 90 cm. On the other hand, in the case of a pedestrian, the size information of the runner on a plane and the width information required for the runner to pass may be input as the same value (for example, 80 cm). In addition, the "plane" in the "motion plane space information" is not limited to a flat surface in the narrow sense, and may include slight unevenness on which the runner can normally move. The degree of slight unevenness depends on the type of runner.

[0067] Moreover, the present invention is not limited to the above-mentioned description of the embodiment of the invention. Various modified embodiments are also included in the present invention within the scope of the claims and within the scope that can be easily conceived by a person skilled in the art. For example, the type of runner is not limited to a general pedestrian, a stroller user, a wheelchair user (without a caregiver), and a wheelchair user (with a caregiver), but may be an electric cart user, a walking aid user, a personal mobility vehicle, a passenger car, a tracked vehicle, or the like. In addition, the method of generating the three-dimensional map data may use a normal aerial photogrammetry method using a drone, or may use a close-up photogrammetry method, etc. Furthermore, the three-dimensional map data is not limited to raster data in which pixels are arranged, but may be vector data configured as a figure. [Explanation of symbols]

[0068] 100 Road surface condition analysis system 110 Input section 120 Extraction part 130 Setting section 140 Judgment section 150 Update section 200 3D map database

Claims

1. an input unit for inputting operation plane space information necessary for a runner traveling on a road surface to move, and height information and depth information of a step that the runner can overcome; an extraction unit that extracts a plurality of drivable areas and non-drivable areas having an area equal to or larger than the operational plane space information from the three-dimensional map data of the road surface; A setting unit that sets the non-drivable area sandwiched between the two driveable areas as a step area; a determination unit that determines whether the runner can overcome the step area based on the step height information and depth information; an update unit that updates the step area that has been determined to be crossoverable from the non-drivable area to a crossoverable area; A road surface condition analysis system comprising:

2. The road surface condition analyzing system according to claim 1 , wherein the operational planar spatial information includes size information of the runner on a plane.

3. 3. The road surface condition analyzing system according to claim 2, wherein when the runner is a wheelchair user, the information on the planar size of the runner is information on dimensions around which the wheelchair can turn.

4. The road surface condition analysis system according to claim 2 , wherein the operational plane spatial information further includes width information required for the runner to pass through.

5. 5. The road surface condition analyzing system according to claim 4, wherein when the runner is a wheelchair user, the width information required for the runner to pass is dimension information allowing the wheelchair to pass.

6. The extraction unit extracts the non-travelable area in a form expanded by an amount corresponding to the operation plane space information, The determination unit is Extending a line segment passing through a predetermined point on a boundary line between the travelable area and the expanded non-travelable area until the line segment reaches another point on the boundary line; determining whether the length of the line segment is equal to or less than the depth of the step; If the depth of the step is equal to or less than the depth of the step, it is determined whether the height of a passing area of ​​the runner along the line segment is equal to or less than the height of the step; The road surface condition analysis system according to claim 1 , wherein when the height of the step is equal to or less than the height of the step, it is determined that the passing area of ​​the runner is traversable.

7. An input step of inputting operation plane space information required for a runner traveling on a road surface to move, and height information and depth information of a step that the runner can overcome; an extraction step of extracting a plurality of drivable areas and non-drivable areas having an area equal to or larger than the operational plane space information from the three-dimensional map data of the road surface; a setting step of setting the non-drivable area sandwiched between the two driveable areas as a step area; a determining step for determining whether the runner can overcome the step area based on the step height information and the step depth information; an updating step of updating the step area determined to be traversable from the non-drivable area to a traversable area; A road surface condition analysis method comprising:

8. An input step of inputting operation plane space information required for a runner traveling on a road surface to move, and height information and depth information of a step that the runner can overcome; an extraction step of extracting a plurality of drivable areas and non-drivable areas having an area equal to or larger than the operational plane space information from the three-dimensional map data of the road surface; a setting step of setting the non-drivable area sandwiched between the two driveable areas as a step area; a determining step for determining whether the runner can overcome the step area based on the step height information and the step depth information; an updating step of updating the step area determined to be traversable from the non-drivable area to a traversable area; A road surface condition analysis program executable on a computer.

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