JP2021060657A - Evaluation system and evaluation method - Google Patents

Abstract

To provide an evaluation system capable of evaluating a ventilation property according to an arrangement of measurement objects provided along a road.SOLUTION: An evaluation system evaluates a ventilation property according to an arrangement of measurement objects provided along a road, and includes an acquisition unit which moves relative to a measurement object and acquires point group data, a voxel generation unit which voxelizes the acquired point group data, a reference plane generation unit which generates a reference plane perpendicular to the road, a collection area setting unit which sets a collection area composed of a plurality of collection blocks collecting the voxels in a direction perpendicular to the reference plane, an integration unit which calculates integration information obtained by integrating attribute information of the voxels contained in each of the collection blocks set by the collection area setting unit, and an evaluation unit which evaluates the ventilation property to the reference plane on the basis of statistical information on the basis of the statistical information calculated by the integration unit.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to an evaluation system and an evaluation method for evaluation based on a point cloud obtained by laser measurement.

Conventionally, it has been important to manage road attachment facilities (trees, guardrails, etc.) provided along the road. For example, in the past, a method of managing the road attachment facilities by image processing using captured images, etc. Has been proposed.

However, in the case of a captured image, there is a problem that it is difficult to accurately grasp the road attachment facility due to the influence of occlusion and shadow.

In this respect, in order to eliminate the influence of occlusion and shadow, a technique for measuring an object to be measured from the result obtained by laser measurement has been proposed in recent years. For example, a technique for measuring an object to be measured by laser measurement from the sky using an aircraft has been proposed (Patent Document 1). In addition, a so-called Mobile Mapping System (MMS) method has been proposed in which a measurement object around the road is laser-measured while traveling on the road.

JP-A-2015-290165

However, no method has been proposed for evaluating the ventilation property based on the arrangement of the road attachment facility, which is the measurement target, when the road attachment facility is measured by laser.

It is an object of the present disclosure to provide an evaluation system and an evaluation method capable of evaluating ventilation based on the arrangement of measurement objects provided along a road.

An evaluation system that evaluates ventilation based on the arrangement of measurement objects provided along a road that follows a certain aspect. An acquisition unit that acquires point cloud data while moving with respect to the measurement object, and acquired points. Aggregation consisting of a voxel generator that converts group data into voxels, a reference plane generator that generates a reference plane perpendicular to the road, and a plurality of aggregate blocks that aggregate voxels in the direction perpendicular to the reference plane. Based on the aggregated area setting unit that sets the area, the integrated unit that calculates the statistical information that integrates the voxel attribute information included in each aggregated block set by the aggregated area setting unit, and the statistical information calculated by the integrated unit. It also has an evaluation unit that evaluates ventilation with respect to the reference surface.

Preferably, the reference plane generation unit generates a reference line based on the point cloud data acquired by the acquisition unit, and generates a reference plane based on the generated reference line.

Preferably, an area width setting unit for setting the depth width of the aggregation area is further provided.
This is an evaluation method for evaluating ventilation based on the arrangement of measurement objects provided along a road that follows a certain aspect, and is a step of acquiring point cloud data while moving with respect to the measurement object, and the acquired point cloud. The step of converting data into voxels, the step of generating a reference plane perpendicular to the road, and the step of setting an aggregation area consisting of multiple aggregation blocks that aggregate voxels in the direction perpendicular to the reference plane. , It is provided with a step of calculating statistical information in which voxel attribute information included in each set aggregate block is integrated, and a step of evaluating ventilation with respect to a reference plane based on the calculated statistical information.

The evaluation system and evaluation method of the present disclosure can evaluate the ventilation property based on the arrangement of the measurement object provided along the road.

It is a figure explaining the outline of the evaluation system 1 according to an embodiment. It is a functional block diagram of the evaluation system 1 according to an embodiment. It is a figure explaining the 3D point cloud data acquired by the point cloud acquisition apparatus 10 according to embodiment. It is a figure explaining the generation of the reference line and the setting of the depth width according to the embodiment. It is a figure explaining the aggregation area set in the aggregation area setting part 24 according to embodiment. It is a figure explaining the measurement object according to embodiment. It is an image diagram in the case where the 3D point cloud data according to the embodiment is voxelized. It is a figure explaining the image in the case of integrating the attribute information of a voxel into the aggregate block SBL according to the embodiment. It is a figure explaining the density information of the measurement object with respect to the reference plane according to an embodiment. It is a figure explaining the case of evaluating the ventilation property with respect to the reference plane according to an embodiment.

The embodiment will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals, and the description thereof will not be repeated.

FIG. 1 is a diagram illustrating an outline of an evaluation system 1 according to an embodiment.
As shown in FIG. 1, in this example, the case where the road is viewed from above is shown. Trees, which are the objects to be measured, are placed on the side of the road.

The tree may be arranged as a windbreak to prevent lateral wind from vehicles traveling on the road. Alternatively, it is not limited to windbreak, and may be arranged for snow protection.

The evaluation system 1 is provided on, for example, a vehicle 100 capable of traveling on a road. In this example, the case where the vehicle 100 is traveling upward in the left lane along the road is shown.

The evaluation system 1 mounted on the travelable vehicle 100 executes laser measurement on a measurement object arranged laterally along the road, and based on the measurement result, performs ventilation based on the arrangement of the measurement object. evaluate. In this example, a case of evaluating ventilation based on the arrangement of trees as an object to be measured will be described as an example.

The evaluation system 1 acquires point cloud data such as trees, which are measurement objects, by using MMS while moving.

FIG. 2 is a functional block diagram of the evaluation system 1 according to the embodiment.
With reference to FIG. 2, the evaluation system 1 includes a point cloud acquisition device 10 and an analysis device 20.

As the point cloud acquisition device 10, a laser scanner can be used as an example.
The point cloud acquisition device 10 is a sensor provided along the road for measuring a tree or the like as a measurement target.

The laser scanner can scan in a plane orthogonal to the direction of travel. The laser scanner irradiates the laser beam while the vehicle 100 is traveling, and receives the laser beam reflected from the tree or the like which is the object to be measured. Based on the time from laser light irradiation to light reception and the laser light irradiation direction, the distance and direction from the laser scanner are measured as distance orientation points for each irradiation point irradiated with the laser light. As a result, three-dimensional point cloud data representing the shape of an object such as a tree of the measurement object arranged along the road as a three-dimensional point cloud is acquired.

The analysis device 20 analyzes the three-dimensional point cloud data acquired by the point cloud acquisition device 10. In this example, the analysis device 20 analyzes and evaluates the ventilation property based on the arrangement of trees and the like of the measurement object arranged along the road.

The analysis device 20 includes a reference plane generation unit 22, an aggregation area setting unit 24, an area width setting unit 26, a voxel generation unit 28, an integration unit 30, and an evaluation unit 32.

The voxel generation unit 28 converts the point cloud data into voxels. A voxel is a regular grid unit in three-dimensional space. In this example, the three-dimensional point cloud data of the laser beam reflected from the tree or the like, which is the measurement target, is voxelized.

The reference plane generation unit 22 generates a predetermined reference plane. The reference plane generation unit 22 generates a plane perpendicular to the reference line as a predetermined reference plane.

The area width setting unit 26 sets the depth width of the area in the vertical direction including the object to be measured with respect to the reference plane.

The aggregation area setting unit 24 sets an aggregation area for aggregating voxel groups based on the reference plane and the depth width set by the area width setting unit 26. The aggregation area is composed of a plurality of aggregation blocks.

The integration unit 30 calculates statistical information that integrates voxel attribute information included in the aggregation block set by the aggregation area setting unit 24.

The evaluation unit 32 evaluates the ventilation property with respect to the reference plane based on the statistical information calculated by the integration unit 30.

FIG. 3 is a diagram illustrating three-dimensional point cloud data acquired by the point cloud acquisition device 10 according to the embodiment.

As shown in FIG. 3, the point cloud acquisition device 10 can acquire the three-dimensional point cloud data of the peripheral region of the evaluation system 1 by scanning the laser scanner. As an example, the three-dimensional point cloud data corresponding to the tree of the measurement object is shown on the left side. In addition, the three-dimensional point cloud data corresponding to the road is shown in the lower right side.

It is possible to identify the type of object based on the reflection intensity of the laser beam reflected from the object. In this example, trees and roads can be identified according to the reflection intensity of the three-dimensional point cloud data.

FIG. 4 is a diagram illustrating generation of a reference line and setting of a depth width according to an embodiment.
With reference to FIG. 4, in this example, a reference line is generated using the three-dimensional point cloud data. Specifically, the reference plane generation unit 22 generates a reference line based on the three-dimensional point cloud data identified as a road among the acquired three-dimensional point cloud data. For example, it is possible to identify a road using three-dimensional point cloud data and extract a road center point of the road width. The reference plane generation unit 22 generates a reference line (road center line) based on the extracted road center points.

The reference plane generation unit 22 generates a plane in the vertical direction as a predetermined reference plane with reference to the generated reference line.

In this example, the case where the reference line is generated using the three-dimensional point cloud data has been described, but the present invention is not limited to this. For example, when the vehicle is equipped with GPS, the reference line is generated using the vehicle trajectory. You may try to do it. A plane in the vertical direction with reference to the reference line may be generated as a predetermined reference plane.

The area width setting unit 26 sets a constant depth width L (predetermined distance L) with reference to the reference line.
The area width setting unit 26 sets a depth line parallel to the reference line as an example.

FIG. 5 is a diagram illustrating an aggregation area set in the aggregation area setting unit 24 according to the embodiment.

FIG. 5A shows an aggregated area when the road is viewed from above. The region between the reference plane in the vertical direction with respect to the reference line and the depth reference plane in the vertical direction with respect to the depth line is the aggregation region.

As shown in FIG. 5B, the aggregation area is composed of a plurality of aggregation blocks SBL.
The aggregation block SBL divides the aggregation region at intervals P along the direction of the reference line, and divides the aggregation area at each height H in the vertical direction of the reference line.

Therefore, the aggregate block SBL is a rectangular parallelepiped having an interval P, a height H, and a depth width L.
The interval P, the height H, and the depth width L can be appropriately adjusted according to the measurement reference of the object to be measured.

In this example, the case where the aggregation region is divided in the vertical direction for each height H and a 7-stage aggregation block SBL is set is shown.

For example, the number of steps may be adjusted according to the height of the tree of the object to be measured.
Further, in this example, the case where the aggregate block SBL is a rectangular parallelepiped has been described as an example, but the aggregate block SBL is not particularly limited to a rectangular parallelepiped.

As shown in FIG. 5C, when the reference line is curved, the shape of the aggregation block SBL also changes along the reference line.

FIG. 6 is a diagram illustrating a measurement object according to the embodiment.
FIG. 6A is a diagram illustrating a tree as a measurement target.

FIG. 6B shows the point cloud data acquired by the point cloud acquisition device 10 acquired by the laser scanner for a part of the tree.

In this example, a case where the point cloud data is voxelized into regular grid units in a three-dimensional space is shown by the voxel generation unit 28. In this example, as an example, a case where 15 three-dimensional point cloud data is included in one voxel is shown.

FIG. 7 is an image diagram when the three-dimensional point cloud data according to the embodiment is voxelized.
As shown in FIG. 7, the voxel generation unit 28 converts the three-dimensional point cloud data into voxels.

Each voxel contains a plurality of three-dimensional point cloud data, and the number of three-dimensional point cloud data is associated with each voxel. Specifically, the number of three-dimensional point cloud data is associated with the position of the center of gravity (voxel point) of the voxel as attribute information.

FIG. 8 is a diagram illustrating an image in the case of integrating voxel attribute information into the aggregate block SBL according to the embodiment.

FIG. 8 shows the center of gravity position (voxel point) BP of each voxelized voxel, and the number of three-dimensional point cloud data is numerically shown as attribute information associated with the voxel point BP.

The integration unit 30 calculates statistical information that integrates the attribute information of the voxels based on the position of the center of gravity of the voxels included in the aggregation block SBL.

As an example, in this example, the aggregation block SBL includes voxel point BPs of 15 voxels, and the case where the attribute information of the voxels is integrated is shown.

FIG. 9 is a diagram for explaining the density information of the measurement object with respect to the reference plane according to the embodiment.
As shown in FIG. 9, the evaluation unit 32 normalizes the statistical information and displays it on the reference plane as density information with respect to the reference plane.

Specifically, the portion darkly displayed with respect to the reference plane indicates the case where the density of the measurement object (tree) in the depth direction with respect to the reference plane is high. The part displayed lightly with respect to the reference plane indicates the case where the density of the measurement object (tree) in the depth direction with respect to the reference plane is low.

FIG. 10 is a diagram illustrating a case where the ventilation property with respect to the reference plane according to the embodiment is evaluated.
As shown in FIG. 10, in this example, the reference plane is divided into a plurality of evaluation regions, and the degree of ventilation for each evaluation region is shown.

Specifically, in this example, the evaluation unit 32 evaluates the degree of ventilation based on the density information for each evaluation area. For example, a region with a high concentration of shading in the evaluation region indicates that the region has a high density of trees and low ventilation. The lightly shaded area in the evaluation area indicates that it is a highly ventilated area.

According to this method, the evaluation system 1 according to the embodiment can evaluate the ventilation property based on the arrangement of the measurement object.

Based on the evaluation result, for example, it becomes easy to identify a place where the road has high ventilation, that is, a place where a vehicle traveling on the road is susceptible to crosswinds, and to arrange a tree or the like at the place. It can also be used for windbreak design and maintenance. Further, the evaluation system 1 may be used not only from the viewpoint of wind protection but also from the viewpoint of snow protection.

In this example, the case of evaluating the ventilation property based on trees or the like, which is the measurement target on the side (left side) of the road, has been described, but it is the measurement target on the side (right side) of the road. Ventilation based on trees and the like may be evaluated at the same time. In addition, trees or the like, which are objects to be measured, may be arranged between roads in which the traveling directions of vehicles are different, and the ventilation property in that case may be evaluated.

In this example, the case of evaluating the ventilation based on the arrangement of trees as an object to be measured has been described, but the ventilation is not limited to trees, for example, the ventilation based on the arrangement of guardrails and other objects is evaluated. Is also possible.

In this example, a case where a highly ventilated part of the road is specified from the viewpoint of windbreak and trees or the like are placed at the part has been described, but from the viewpoint of safety and crime prevention, a vehicle traveling on the road has been described. It is also possible to evaluate the good visibility from the side perspective. In that case, a portion of the road having low ventilation may be identified and work may be performed to increase the ventilation of the portion.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present disclosure is shown by the scope of claims, not the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 evaluation system, 10 point cloud acquisition device, 20 analysis device, 22 reference plane generation unit, 24 aggregation area setting unit, 26 area width setting unit, 28 voxel generation unit, 30 integration unit, 32 evaluation unit.

Claims (4)

It is an evaluation system that evaluates ventilation based on the arrangement of measurement objects provided along the road.
An acquisition unit that acquires point cloud data while moving with respect to the measurement object,
A voxel generator that converts the acquired point cloud data into voxels,
A reference plane generator that generates a reference plane perpendicular to the road,
An aggregation area setting unit that sets an aggregation area composed of a plurality of aggregation blocks that aggregate voxels in a direction perpendicular to the reference plane, and an aggregation area setting unit.
An integration unit that calculates statistical information that integrates voxel attribute information included in each aggregation block set by the aggregation area setting unit, and an integration unit.
An evaluation system including an evaluation unit that evaluates ventilation with respect to the reference plane based on statistical information calculated by the integrated unit. The evaluation system according to claim 1, wherein the reference plane generation unit generates a reference line based on the point cloud data acquired by the acquisition unit, and generates the reference plane based on the generated reference line. The evaluation system according to claim 2, further comprising an area width setting unit for setting the depth width of the aggregated area. It is an evaluation method that evaluates ventilation based on the arrangement of measurement objects provided along the road.
A step of acquiring point cloud data while moving with respect to the measurement object, and
Steps to voxel the acquired point cloud data,
A step of generating a reference plane perpendicular to the road,
A step of setting an aggregation area composed of a plurality of aggregation blocks that aggregate voxels in a direction perpendicular to the reference plane, and
A step of calculating statistical information that integrates voxel attribute information included in each of the set aggregate blocks, and
An evaluation method including a step of evaluating ventilation with respect to the reference plane based on the calculated statistical information.

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