Surface evaluation method and surface evaluation system

Abstract

To provide a surface evaluation method and a surface evaluation system that can easily acquire highly accurate measurement data regardless of the mesh size.SOLUTION: A surface evaluation method according to an embodiment comprises a process for acquiring a plurality of measurement data by measuring an object surface X at regular intervals while moving a measurement device along an object surface X, a process for mapping each measurement data to a measurement point P that is the position at which each measurement data has been measured by the location positioning system, a process for setting a mesh M on the object surface X, a process for setting the measurement area K as the area around the measurement point P in the object surface X, a peripheral mesh assignment process for assigning measurement data to the mesh M overlapping the measurement area K, and a process for evaluating each mesh M on the object surface X based on the assigned measurement data.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a surface evaluation method and a surface evaluation system for evaluating a target surface that is a surface to be measured.

Background Art

[0002] Patent Document 1 describes a quality management system for quality management of erection work that is transported and tightened. The quality management system manages the quality of erection materials that form an erected structure by tightening. The quality management system includes steps of acquiring quality information of the erection materials, acquiring erection position information and tightening information of the transported erection materials after acquisition of quality management, and collating the quality information with the erection position information and the tightening information.

[0003] In the step of acquiring the tightening information, the number of rolling presses by the tightening machine is calculated for each of a plurality of rectangular tightening target areas from the movement path of the tightening machine. In the acquisition of the number of rolling presses, when the tightening machine reaches each vertex of the tightening target area once, the number of rolling presses of the tightening target area is incremented by 1. Thus, the number of rolling presses is acquired for each of the plurality of tightening target areas, and the acquired number of rolling presses is transmitted in real time.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, a method is known in which a rectangular mesh is set on the target surface, such as the compaction target area mentioned above, and a measuring device measures the target surface while moving along it. The measurement data is then assigned to one mesh where the measuring point of the measuring device is located, and the target surface is evaluated mesh by mesh. However, with this method, even if the measuring device actually measures a wide area of ​​the target surface, the measurement data is only assigned to one mesh where the measurement point is located, which can lead to the problem that only measurement data for a narrow area can be obtained. This problem is particularly pronounced when the mesh size is small. In this case, it is necessary to move the measuring device to fill all the meshes, which requires a great deal of effort for measurement.

[0006] On the other hand, when the mesh size is large, the above problems are less likely to occur. However, in this case, since measurement data from many measurement points is assigned to a large mesh, a problem may arise in which the accuracy of the measurement data assigned to the mesh decreases. Therefore, it is necessary to be able to easily acquire high-precision measurement data regardless of the mesh size.

[0007] This disclosure aims to provide a surface evaluation method and a surface evaluation system that can easily acquire highly accurate measurement data regardless of the mesh size. [Means for solving the problem]

[0008] The surface evaluation method relating to this disclosure is (1) a surface evaluation method for evaluating a target surface which is the surface to be measured. The surface evaluation method comprises the steps of: moving the measuring device along the target surface and having the measuring device measure the target surface at regular intervals to acquire multiple measurement data; associating each measurement data with a measurement point which is the position where each measurement data was measured using a positioning system; setting a mesh on the target surface; setting a measurement area as the region around the measurement points on the target surface as the measurement area; assigning measurement data to meshes where the measurement areas overlap; and evaluating the target surface mesh by mesh from the assigned measurement data.

[0009] In this surface evaluation method, a measuring device moves across the target surface and measures it at regular intervals, acquiring multiple measurement data points. Each measurement data point is associated with a measurement point, which is the location where the measurement was taken. This allows for obtaining multiple measurement data points for each of the multiple measurement points. A mesh is set on the target surface, and the area surrounding the measurement points on the target surface is set as the measurement area. Then, a surrounding mesh assignment process is performed in which measurement data is assigned to meshes where the measurement areas overlap, and the target surface is evaluated mesh by mesh based on the assigned measurement data. Therefore, since measurement data is assigned to multiple meshes around the measurement points, measurement data can be obtained over a wide area. Thus, many meshes can be filled without having to move the measuring device many times, making it easy to measure the target surface. This surface measurement can be easily performed even when the mesh size is small, so high-precision measurement data can be easily obtained regardless of the mesh size.

[0010] (2) In (1) above, the surface evaluation method may further include a single mesh assignment step of assigning measurement data to a mesh containing measurement points. Both the peripheral mesh assignment step and the single mesh assignment step may be performed, and either the measurement data assigned in the peripheral mesh assignment step or the measurement data assigned in the single mesh assignment step may be deleted from the mesh to which measurement data has been assigned in both the peripheral mesh assignment step and the single mesh assignment step. In this case, by performing both the single mesh assignment step and the peripheral mesh assignment step, highly accurate measurement data can be easily obtained regardless of the size of the mesh.

[0011] (3) In (1) or (2) above, in the peripheral mesh assignment step, measurement data may be assigned to a mesh in which the measurement area overlaps with the center of the mesh. In this case, measurement data can be assigned to a mesh in which the measurement area overlaps with the center of the mesh.

[0012] (4) In any of the above steps (1) to (3), the measurement area may be set according to the measurement sensitivity of the measuring device. In this case, the measurement sensitivity of the measuring device is taken into account when setting the measurement area, so that more accurate measurement data can be obtained.

[0013] (5) In any of the above steps (1) to (4), the step of setting the measurement area may be set according to the direction of travel of the measuring device on the target surface. In this case, the direction of travel of the measuring device is taken into account when setting the measurement area, so that more accurate measurement data can be obtained.

[0014] (6) In any of (1) to (5) above, the target surface may be a compacted embankment surface. In this case, the embankment surface can be easily measured, and highly accurate measurement data of the embankment surface can be obtained regardless of the mesh size.

[0015] (7) In any of (1) to (6) above, in the surrounding mesh assignment step, the area of ​​the region where the measurement area overlaps with the mesh may be calculated each time the measuring device performs a measurement. In the evaluation step, the value obtained by dividing the sum of the products of the ratio of the area of ​​the overlapping region to the area of ​​the mesh and the measurement data by the sum of said ratios may be evaluated. In this case, the measurement data can be assigned to the mesh by weighting the area of ​​the region where the measurement area overlaps with the mesh, thereby obtaining measurement data with even higher accuracy.

[0016] (8) In any of the above steps (1) to (7), the evaluation step may take into account the measurement sensitivity of the measuring device according to its position within the measurement area and evaluate the target surface for each mesh. In this case, the measurement sensitivity of the measurement area overlapping the mesh is taken into account when assigning measurement data, so even more accurate measurement data can be obtained.

[0017] (9) In any of the above steps (1) to (8), the measuring device may acquire the resistivity of the embankment as measurement data. In this case, since the resistivity of the embankment is acquired, the embankment after compaction can be evaluated easily and with high accuracy.

[0018] (10) In any of the above (1) to (8), in the step of acquiring measurement data, one of the multiple measuring devices may acquire the resistivity of the embankment as measurement data, and the other of the multiple measuring devices may acquire the dielectric constant as measurement data. In this case, the dry density and water content of the embankment can be calculated from the resistivity and dielectric constant of the embankment. Therefore, the evaluation of the embankment can be performed with even higher accuracy.

[0019] The surface evaluation system relating to this disclosure is (11) a surface evaluation system for evaluating a target surface which is the surface to be measured. The surface evaluation system comprises: a measuring device that moves along the target surface and measures the target surface at regular intervals to acquire multiple measurement data; a positioning system that associates each measurement data with a measurement point which is the position where each measurement data was measured; a mesh setting unit that sets a mesh on the target surface; a measurement area setting unit that sets a measurement area as the region around the measurement points on the target surface; a peripheral mesh assignment unit that assigns measurement data to meshes where the measurement areas overlap; and an evaluation unit that evaluates the target surface mesh by mesh from the assigned measurement data.

[0020] In this surface evaluation system, a measuring device measures a target surface at regular intervals while moving on the target surface to obtain a plurality of measurement data, and a positioning system associates measurement points, which are the positions at which the respective measurement data are measured, with the measurement data, so that a plurality of measurement data for each of the plurality of measurement points can be obtained. A mesh setting unit sets a mesh on the target surface, and a measurement area setting unit sets an area around the measurement point on the target surface as a measurement area. A peripheral mesh allocation unit allocates the measurement data to the meshes where the measurement areas overlap, and an evaluation unit evaluates the target surface for each mesh from the allocated measurement data. Therefore, since the measurement data are allocated to a plurality of meshes around the measurement point, a wide range of measurement data can be obtained, and many meshes can be filled without causing the measuring device to travel frequently. Thus, the measurement of the target surface can be easily performed. Further, the measurement of the target surface can be easily performed even when the size of the mesh is small, so that highly accurate measurement data can be easily obtained regardless of the size of the mesh.

Advantages of the Invention

[0021] According to the present disclosure, highly accurate measurement data can be easily obtained regardless of the size of the mesh.

Brief Description of the Drawings

[0022] [Figure 1] It is a diagram showing a surface evaluation system according to an embodiment. [Figure 2] It is a diagram showing the measuring device of the surface evaluation system of FIG. 1. [Figure 3] It is a diagram for explaining the measurement principle of the measuring device of FIG. 2. [[ID= / / ID=22]] [Figure 4] It is a diagram for explaining the allocation of meshes in the surface evaluation method according to the embodiment. [Figure 5] It is a diagram for explaining a single mesh allocation step in the surface evaluation method according to the embodiment. [Figure 6] It is a diagram for explaining a peripheral mesh allocation step in the surface evaluation method according to the embodiment. [Figure 7]This figure illustrates the peripheral mesh assignment process of the surface evaluation method according to the embodiment. [Figure 8] Figures (a) and (b) show examples in which both a single mesh assignment process and a peripheral mesh assignment process are performed. [Figure 9] This diagram illustrates the peripheral mesh allocation process related to the first modified example. [Figure 10] This diagram illustrates the process of assigning surrounding meshes to the second modified example. [Figure 11] This figure schematically shows a measuring device relating to the third modified example. [Figure 12] This figure shows the measurement points by the measuring device according to the fourth modified example. [Figure 13] This is a diagram showing the surface evaluation system related to the fifth modified example. [Modes for carrying out the invention]

[0023] The following describes embodiments of the surface evaluation method and surface evaluation system related to this disclosure with reference to the drawings. In the description of the drawings, the same or equivalent elements are denoted by the same reference numeral, and redundant explanations are omitted as appropriate. For the sake of ease of understanding, some parts of the drawings may be simplified or exaggerated, and the dimensional ratios, etc., are not limited to those shown in the drawings.

[0024] The surface evaluation system 1 and surface evaluation method according to this embodiment are used, for example, at a site A where a dam is constructed. At site A, for example, soil is transported by dump trucks, the transported soil is spread out by bulldozers, and the spread soil is compacted by vibratory rollers. The vibratory roller compacts the soil by moving back and forth multiple times at site A, thereby compacting the embankment B at site A.

[0025] For example, the surface evaluation system 1 is an embankment evaluation system that evaluates the embankment B (soil) at site A while moving along the embankment surface S, which is a compacted surface after being compacted by a compaction machine such as a vibratory roller. In this embodiment, the embankment surface S corresponds to the surface to be measured by the surface evaluation system 1. The embankment surface S is a construction surface formed by compaction. The surface evaluation system 1 calculates, for example, at least one of the dry density of embankment B and the water content of embankment B as evaluation items for embankment B.

[0026] For example, the surface evaluation system 1 evaluates embankment B by measuring its dry density and water content, and measures, for example, the effect of compaction by a compaction machine. Embankment B may be composed of, for example, CSG, RCD, or cover soil from a radioactive disposal project.

[0027] The surface evaluation system 1 includes a resistivity measuring device 10 (measuring device) for measuring the resistivity of the embankment B. For example, the surface evaluation system 1 may also include a data acquisition unit 31 for collecting measurement data of the resistivity of the embankment B. For example, the data acquisition unit 31 is an information terminal such as a personal computer. For example, the surface evaluation system 1 includes a linear body 3 extending from the resistivity measuring device 10. For example, the linear body 3 is a string-like body.

[0028] For example, the surface evaluation system 1 includes a traction unit 30 for towing the resistivity measuring device 10. The traction unit 30 has, for example, a plurality of wheels 30b, a base 30c connecting the upper parts of the plurality of wheels 30b, and a handle 30d extending upward from the base 30c. The base 30c is connected to the resistivity measuring device 10 via a linear body 3, and by holding the handle 30d with the wheels 30b on the raised surface S and rolling the wheels 30b on the raised surface S, the traction unit 30 and the resistivity measuring device 10 can be moved on the raised surface S. As an example, the data acquisition unit 31 is provided on the base 30c. However, the location of the data acquisition unit 31 is not particularly limited.

[0029] Figure 2 is a schematic diagram of the resistivity measuring device 10. Figure 3 is a schematic diagram showing the configuration of the electrodes 20 of the resistivity measuring device 10. For example, the resistivity measuring device 10 is a portable device. The resistivity measuring device 10 measures the resistivity of the embankment B at site A while moving along the embankment surface S after it has been compacted by a compaction machine.

[0030] The resistivity measuring device 10 is equipped with four electrodes 20, which are capacitor electrodes. For example, the arrangement of the electrodes 20 in the resistivity measuring device 10 conforms to the dipole-dipole method. The four electrodes 20 consist of a pair of potential electrodes 21 and a pair of current electrodes 22. The resistivity measuring device 10 measures the resistivity of the embankment B using the four-electrode method. Each of the potential electrodes 21 and current electrodes 22 is positioned close to the embankment surface S.

[0031] A pair of potential electrodes 21 and a pair of current electrodes 22 are arranged so as to be aligned along the direction of travel D1 of the resistivity measuring device 10. In this embodiment, the direction in which the multiple electrodes 20 are aligned coincides with the direction of travel D1 of the resistivity measuring device 10. Thus, the relationship between the direction in which the multiple electrodes 20 are aligned and the direction of travel D1 is predetermined. As an example, a pair of potential electrodes 21 are arranged on the rear side of the direction of travel of the resistivity measuring device 10, and a pair of current electrodes 22 are arranged on the front side of the same direction of travel. For example, the pair of potential electrodes 21 and the pair of current electrodes 22 are arranged in a dipole-dipole configuration. However, the arrangement of the pair of potential electrodes 21 and the pair of current electrodes 22 may be in an arrangement other than a dipole-dipole configuration, and is not particularly limited.

[0032] The resistivity measuring device 10 includes an electrode 20, a holder 41 that holds the electrode 20, and a plurality of casters 42 that support the holder 41 so that it can move while the holder 41 is separated from the embankment surface S. The resistivity measuring device 10 includes, for example, two holders 41 and a linear body 48 that extends between the two holders 41 along the direction of travel D1.

[0033] The linear body 48 is, for example, detachable from the holder 41. When this linear body 48 is provided, when one of the two holders 41 (for example, the holder 41 that holds the current electrode 22) is pulled in the direction of travel D1, one of the two holders 41 and the other can be moved along the direction of travel D1. In addition, by preparing multiple types of linear bodies 48 with different lengths and attaching a linear body 48 selected from the multiple types of linear bodies 48, the distance between the potential electrode 21 and the current electrode 22 can be changed.

[0034] For example, the holder 41 includes a plurality of electrode holders 43 that hold each of the pair of potential electrodes 21 and the pair of current electrodes 22 facing the embankment B. The electrode holders 43 hold the electrodes 20 so that they can move along a direction D2 that intersects the direction of travel D1. Direction D2 is, for example, the vertical direction.

[0035] The electrode holder 43 has a plurality of spring mechanisms 46 that bias the electrode 20 toward the embankment B side (downward). When the holder 41 travels and there is unevenness on the embankment surface S, the electrode holder 43 and the electrode 20 come into contact with the unevenness, and the electrode 20 moves in direction D2. At this time, the spring mechanisms 46 bias the electrode 20 toward the embankment B, so that the electrode 20 can follow the unevenness on the embankment surface S.

[0036] The potential electrode 21 and the current electrode 22 are dragged, for example, on a raised surface S. Each of the potential electrode 21 and the current electrode 22 has a dielectric 23 facing the raised surface S and a conductor 24 electrically connected to the dielectric 23. The dielectric 23 is, for example, a plate-shaped member made of synthetic resin.

[0037] Since the dielectric 23 is in contact with and dragged on the raised surface S, it is preferable that it be made of a material that can withstand contact with the raised surface S. The dielectric 23 includes, for example, at least one of high-density polyethylene, rigid polyurethane, and ABS (Acrylonitrile Butadiene Styrene) resin.

[0038] The conductor 24 is a flat plate containing a conductive metal. The resistivity measuring device 10 further includes an AC power supply 25 and a potentiometer 26. The AC power supply 25 is electrically connected to the conductor 24 of each current electrode 22. The potentiometer 26 is electrically connected to the conductor 24 of each potential electrode 21.

[0039] The AC power supply 25 applies an AC voltage between the pair of current electrodes 22. This causes an AC current to flow through the embankment B. For example, when a voltage is applied to the conductors 24 of the pair of current electrodes 22 that are not in contact with the embankment surface S, charge accumulates between the conductors 24 and the embankment B, and the current electrodes 22 become capacitors. If the AC power supply 25 switches the polarity of the voltage before the capacitor-like current electrodes 22 are fully charged or discharged, an AC current will flow continuously through the embankment B, which has resistance. The potentiometer 26 measures the potential between the pair of potential electrodes 21, which have become capacitors similar to the current electrodes 22.

[0040] The resistivity measuring device 10 measures the resistivity of the embankment B at a constant sampling period while moving (while the traction unit 30 is running). For example, the resistivity measuring device 10 measures the resistivity of the embankment B once per second while moving. When sensitivity analysis (e.g., FEM analysis) is performed on the resistivity measurement, the resistivity of a certain range E and its average value are measured in a single measurement. In a plan view, the certain range E has an oval shape with a major axis extending along the direction in which the multiple electrodes 20 are aligned. For example, the longitudinal direction of the certain range E coincides with the direction of travel D1 of the resistivity measuring device 10. In this way, the longitudinal direction of the certain range E and the direction of travel D1 of the resistivity measuring device 10 are linked in advance. As described above, the measurement range of the resistivity measuring device 10 extends to the certain range E, not just a single point. However, the measured resistivity data is stored in the data acquisition unit 31 as the measurement result at one measurement point P.

[0041] As shown in Figures 1 and 2, the surface evaluation system 1 includes a resistivity measuring device 10 that moves along the embankment surface S, which is the target surface X to be measured, and measures the embankment surface S to acquire multiple resistivity measurement data, and a positioning system 15 that associates each measurement data with a measurement point P (position information) which is the location where each measurement data was measured. The positioning system 15 is, for example, a GNSS (Global Navigation Satellite System) antenna installed in the surface evaluation system 1. In this case, resistivity measurement data for each measurement point P of the embankment B measured by the GNSS antenna is stored in the data acquisition unit 31.

[0042] As shown in Figures 1 and 4, the surface evaluation system 1 has, for example, a surface evaluation application 50 installed on an information terminal T. The information terminal T may be, for example, a personal computer. The information terminal T includes, as an example, a processor (e.g., CPU) that runs an operating system and software (applications), a main memory unit composed of ROM and RAM, an auxiliary memory unit composed of flash memory or the like, a communication control unit composed of a wireless communication module or the like, an input device, and an output device such as a display. However, the configuration of the information terminal T is not limited to the above and can be changed as appropriate.

[0043] Each functional element of the information terminal T is realized by loading the software of the surface evaluation application 50 into the processor or storage unit (for example, the main memory unit or auxiliary memory unit mentioned above) of the information terminal T and executing the software. The processor operates the communication control unit, input device, or output device mentioned above according to the software, and reads and writes data to the storage unit. The data or database used for processing in the information terminal T is stored in the storage unit.

[0044] The surface evaluation application 50 evaluates the measurement data (measurement data associated with measurement points P) stored in the data acquisition unit 31. The surface evaluation application 50 has, as functional elements, a mesh setting unit 51 that sets a mesh M on the target surface X (for example, a raised surface S), a single mesh assignment unit 52 that assigns measurement data such as resistivity to the mesh M that includes the measurement points P, and an evaluation unit 53 that evaluates the target surface X from the assigned measurement data.

[0045] The mesh setting unit 51 displays the mesh M along with the target surface X on the display T1 of the information terminal T, for example. The mesh M is rectangular (or square, for example). The length of one side of the mesh M (the length of one side of the portion of the target surface X enclosed by the mesh M, the size of the mesh M) is, for example, 0.5 m or more and 2 m or less. The size of the mesh M is a predetermined value.

[0046] The single-mesh assignment unit 52 assigns the measurement data to a mesh M that includes the measurement point P, using the measurement point P associated with the measurement data. However, even if the resistivity measuring device 10 is intended to move in a straight line, the path taken by the resistivity measuring device 10 will be somewhat zigzagging due to the influence of deviations in the trajectory of the resistivity measuring device 10, variations in speed, or variations in GNSS.

[0047] The evaluation unit 53 evaluates the measurement data assigned to each mesh M. The evaluation unit 53 performs statistical processing on the multiple measurement data assigned to each mesh M to calculate representative values ​​for the measurement data for each mesh M. For example, the evaluation unit 53 calculates the density and water content of the embankment B in mesh M from the volumetric water content and resistivity assigned to mesh M.

[0048] As mentioned above, when the single mesh assignment unit 52 assigns measurement data to a mesh containing measurement point P, the resistivity measuring device 10 assigns measurement data only to the mesh M containing measurement point P, even though it is measuring a certain range E. Therefore, contrary to the characteristics of resistivity measurement, there was a situation where the target surface X, which is in line with the actual measurements of the resistivity measuring device 10, could not be evaluated.

[0049] For example, as shown in Figures 4 and 5, if the mesh size (mesh size) of mesh M is small, even though the resistivity measuring device 10 measures the average resistivity including the surrounding mesh M, the evaluation unit 53 calculates a representative value for mesh M, resulting in a measurement that appears to have only measured a limited, narrow range. In other words, because measurement data is only assigned to the mesh M containing the measurement point P within the actual measurement range Y of the resistivity measuring device 10, the range of measurement data evaluated by the evaluation unit 53 (the sum of the areas of the colored mesh M in Figure 5) can become extremely narrow. Therefore, in order to evaluate all of mesh M, the resistivity measuring device 10 must be advanced many times to fill all of mesh M, which requires a great deal of effort and time for measurement.

[0050] To solve the above problems, the surface evaluation system 1 (surface evaluation application 50) according to this embodiment includes, as shown in Figures 1 and 6, a measurement area setting unit 54 that sets the measurement area K as the region around the measurement point P on the target surface X, and a peripheral mesh assignment unit 55 that assigns measurement data to the mesh M that overlaps with the measurement area K.

[0051] The measurement area setting unit 54 sets the measurement area K based on the resistivity measurement at measurement point P, for example, based on the sensitivity analysis of the resistivity measuring device 10. For example, the measurement area setting unit 54 sets the measurement area K according to the direction of travel D1 of the resistivity measuring device 10. As a specific example, the measurement area setting unit 54 sets a rectangular measurement area K having a pair of long sides K1 extending in the direction of travel D1 and a pair of short sides K2 extending in an orthogonal direction D3 perpendicular to the direction of travel D1 in a plan view. As an example, the length of the long sides K1 is 3m and the length of the short sides K2 is 2m.

[0052] As described above, when the measurement area setting unit 54 sets a rectangular measurement area K, there is an advantage in that the calculation and evaluation of the measurement data assigned to the mesh M can be easily performed. However, the shape of the measurement area set by the measurement area setting unit 54 is not particularly limited and may be an ellipse, oblong, circular, or polygonal shape.

[0053] The peripheral mesh assignment unit 55 assigns measurement data to the meshes M that overlap with the measurement area K. For example, the peripheral mesh assignment unit 55 assigns measurement data to all meshes M that overlap with the measurement area K at the center N of the mesh M. The "center of the mesh" is, for example, the centroid of the mesh. That is, in a figure such as a mesh that exhibits a polygonal shape, such as a rectangle, the center coincides with the centroid. In the example in Figure 6, measurement data is assigned to meshes M1, M2, M3, M4, M5, and M6. As a result, one measurement data is assigned to multiple meshes M around the measurement point P.

[0054] The peripheral mesh assignment unit 55 assigns one measurement data to multiple meshes M surrounding the measurement point P, enabling evaluation of the target surface X that more closely reflects the actual measurement by the resistivity measuring device 10. Therefore, since it is possible to evaluate the target surface X in accordance with the resistivity measurement by the resistivity measuring device 10, including the surrounding meshes M, the range of measurement data evaluated by the evaluation unit 53 can be widened regardless of the mesh size.

[0055] Hereinafter, the allocation of measurement data by the single-mesh allocation unit 52 will be referred to as the single-mesh allocation method, and the allocation of measurement data by the surrounding mesh allocation unit 55 will be referred to as the surrounding mesh allocation method. Table 1 shows the summary statistics for each mesh size using the single-mesh allocation method. Table 2 shows the summary statistics for each mesh size using the surrounding mesh allocation method. In calculating each summary statistic, the number of raw data points was 2298, the maximum value was 2.38, the minimum value was 1.68, the mean value was 2.05, the standard deviation was 0.161, and the coefficient of variation was 0.079. [Table 1] [Table 2]

[0056] As shown in Tables 1 and 2, in the single-mesh assignment method (Table 1), the smaller the mesh size, the smaller the proportion of meshes to which measurement data is assigned, resulting in a large change in standard deviation due to mesh size. In the single-mesh assignment method, when the mesh size is small (1m), the standard deviation is 0.096. On the other hand, in the peripheral mesh assignment method (Table 2), the change in standard deviation due to mesh size is mitigated. In the peripheral mesh assignment method, even with a small mesh size, measurement data is assigned to multiple meshes, thus mitigating the impact of mesh size.

[0057] Furthermore, as shown in Figure 7, in the case of the peripheral mesh allocation method, if the measurement area K is significantly larger than the mesh size, it may occur that no measurement data is assigned to any mesh M because there is no mesh M in which the measurement area K overlaps with the center N.

[0058] In the surface evaluation method according to this embodiment, in order to avoid the above, both the assignment of measurement data using the single mesh assignment method and the assignment of measurement data using the peripheral mesh distribution method are performed, as shown in Figures 8(a) and 8(b). Below, an example of the steps of the surface evaluation method according to this embodiment will be described.

[0059] First, as shown in Figure 4, the resistivity measuring device 10 is moved along the raised surface S, and the resistivity measuring device 10 measures the raised surface S at regular intervals to acquire multiple resistivity measurement data (step of acquiring measurement data). At this time, the positioning system 15 associates each measurement data with a measurement point P, which is the position where each measurement data was measured (step of associating). After multiple measurement data linked to measurement point P have been acquired, the mesh setting unit 51 sets a mesh M on the target surface X (step of setting the mesh).

[0060] Next, as shown in Figure 8(a), a single-mesh assignment process is performed in which measurement data is assigned to a mesh M containing the measurement point P. At this time, the single-mesh assignment unit 52 assigns the measurement data to the mesh M (mesh M1) containing the measurement point P using the single-mesh assignment method.

[0061] Subsequently, as shown in Figure 8(b), the peripheral mesh allocation method is executed. More specifically, the measurement area setting unit 54 sets the area around the measurement point P on the target surface X as the measurement area K (step of setting the measurement area). For example, the measurement area setting unit 54 sets the measurement area K according to the measurement sensitivity of the resistivity measuring device 10.

[0062] As an example, the measurement area setting unit 54 may set a measurement area K corresponding to a certain range E within the measurement range of the resistivity measuring device 10 (for example, a shape similar to a certain range E in a plan view). Alternatively, the measurement area setting unit 54 may set the measurement area K according to the direction of travel D1 of the resistivity measuring device 10. As an example, the measurement area setting unit 54 may set a rectangular measurement area K having a long side K1 extending along the direction of travel D1.

[0063] After the measurement area K is set, the surrounding mesh assignment unit 55 assigns measurement data to the mesh M that overlaps with the measurement area K (surrounding mesh assignment process). At this time, measurement data is assigned to the mesh M in which the measurement area K overlaps with the center of the mesh M. As an example, the surrounding mesh assignment unit 55 assigns measurement data to meshes M1 to M6. After performing both the single mesh assignment method and the surrounding mesh distribution method in this way, the evaluation unit 53 performs an evaluation of each mesh M.

[0064] The evaluation unit 53 deletes either the measurement data assigned using the peripheral mesh allocation method or the measurement data assigned using the single mesh allocation method from a mesh M to which measurement data has been assigned using both the peripheral mesh allocation method and the single mesh allocation method. In other words, the evaluation unit 53 deletes one of the measurement data that has been assigned twice to the same mesh M. In the examples of Figures 8(a) and 8(b), the evaluation unit 53 deletes one of the measurement data assigned to mesh M1. After that, the evaluation unit 53 performs an evaluation (evaluation process) of the target surface X from the measurement data assigned to mesh M for each mesh M, and the series of processes is completed.

[0065] Next, the effects and advantages obtained from the surface evaluation system 1 and surface evaluation method according to this embodiment will be described in detail. In the surface evaluation system 1 and surface evaluation method according to this embodiment, the resistivity measuring device 10 moves on the target surface X and measures the target surface X at regular intervals, thereby acquiring multiple measurement data, and each measurement data is associated with a measurement point P, which is the position where it was measured. As a result, multiple measurement data can be obtained for each of the multiple measurement points P.

[0066] A mesh M is set on the target surface X, and the area around the measurement point P on the target surface X is set as the measurement area K. Then, a surrounding mesh assignment process is performed in which measurement data is assigned to the mesh M that overlaps with the measurement area K, and the target surface X is evaluated for each mesh M from the assigned measurement data. As a result, since measurement data is assigned to multiple mesh M around the measurement point P, measurement data can be obtained over a wide area. Therefore, since many mesh M can be filled without having to travel long distances with the resistivity measuring device 10, measurement of the target surface X can be easily performed. This measurement of the target surface X can be easily performed even when the size of the mesh M is small, so high-precision measurement data can be easily obtained regardless of the size of the mesh M.

[0067] The surface evaluation method according to this embodiment further comprises a single-mesh assignment step of assigning measurement data to a mesh M containing a measurement point P. Both the peripheral mesh assignment step and the single-mesh assignment step are performed, and from the mesh M (mesh M1) to which measurement data has been assigned in both the peripheral mesh assignment step and the single-mesh assignment step, either the measurement data assigned in the peripheral mesh assignment step or the measurement data assigned in the single-mesh assignment step is deleted. In this way, by performing both the single-mesh assignment step and the peripheral mesh assignment step, highly accurate measurement data can be easily obtained regardless of the size of the mesh M. Even when the size of the mesh M is significantly large, as shown in Figure 7, measurement data can be assigned to at least one mesh M using the single-mesh assignment method.

[0068] In this embodiment, the measurement area K may be set according to the measurement sensitivity of the resistivity measuring device 10 during the step of setting the measurement area. In this case, the measurement sensitivity of the resistivity measuring device 10 (for example, a certain range E indicating the area covered by the resistivity measuring device 10) is taken into account when setting the measurement area K, so that more accurate measurement data can be obtained.

[0069] In this embodiment, in the peripheral mesh assignment process, measurement data is assigned to the mesh M in which the measurement area K overlaps the center of the mesh M. In this case, measurement data can be assigned to the mesh M in which the measurement area K overlaps the center of the mesh M.

[0070] In this embodiment, the step of setting the measurement area may be set according to the direction of travel D1 of the resistivity measuring device 10 on the target surface X. In this case, since the direction of travel D1 of the resistivity measuring device 10 is taken into account when setting the measurement area K, more accurate measurement data can be obtained.

[0071] In this embodiment, the target surface X is a compacted embankment surface S. Therefore, measurement of the embankment surface S can be easily performed, and highly accurate measurement data of the embankment surface S can be obtained regardless of the size of the mesh M.

[0072] In this embodiment, during the process of acquiring measurement data, the resistivity measuring device 10 acquires the resistivity of the embankment B as measurement data. Therefore, since the resistivity of the embankment B is acquired, the embankment B after compaction can be evaluated easily and with high accuracy.

[0073] Next, various modifications of the surface evaluation method and surface evaluation system according to this disclosure will be described. Some steps of the surface evaluation method according to the modifications are the same as some steps of the surface evaluation method according to the embodiment described above. Some components of the surface evaluation system according to the modifications are the same as some components of the surface evaluation system 1 described above. Therefore, the same reference numerals are used for descriptions that are the same as those described above and are omitted as appropriate.

[0074] (First variation) As shown in Figure 9, for example, in the peripheral mesh allocation process, the evaluation unit 53 calculates the area of ​​the region F where the measurement area K overlaps with the mesh M each time the resistivity measuring device 10 performs a measurement. The evaluation unit 53 evaluates the value obtained by dividing the sum of the products of the ratio of the area of ​​the overlapping region F to the area of ​​the mesh M and the measurement data by the sum of said ratios. As a specific example, when the measurement data value is C1 and the ratio of the area of ​​the overlapping region F to the area of ​​the mesh M is w1 in the first measurement, and the measurement data value is C2 and the ratio of the area of ​​the overlapping region F to the area of ​​the mesh M is w2 in the second measurement, the evaluation value is calculated by equation (1). Evaluation value = ((C1 × w1) + (C2 × w2)) / w1 + w2 The evaluation unit 53 performs the aforementioned evaluation using this evaluation value as measurement data assigned to mesh M.

[0075] In the surface evaluation method according to the first modified example described above, in the peripheral mesh assignment step, the resistivity measuring device 10 calculates the area of ​​region F where the measurement area overlaps with mesh M each time it performs a measurement. In the evaluation step, the value obtained by dividing the sum of the products of the ratio of the area of ​​overlapping region F to the area of ​​mesh M and the measurement data by the sum of said ratios is evaluated. Therefore, since the area of ​​region F where the measurement area K overlaps with mesh M is weighted and the measurement data can be assigned to mesh M, even more accurate measurement data can be obtained.

[0076] (Second variation) As shown in Figure 10, for example, the evaluation unit 53 evaluates the target surface X for each mesh M in the evaluation process, taking into account the measurement sensitivity G of the resistivity measuring device 10 according to its position within the measurement area K. For example, the measurement sensitivity G decreases as the distance from the center of the resistivity measuring device 10 in a plan view increases. In the second modified example, the peripheral mesh assignment unit 55 assigns the measurement data so that it has a large influence on the mesh M close to the center of the resistivity measuring device 10, and assigns the measurement data so that it has a small influence on the mesh M further away from the center of the resistivity measuring device 10.

[0077] For example, the evaluation unit 53 may divide the sensitivity distribution by the area of ​​the region F (see Figure 9) where the measurement area K overlaps with the mesh M, and then use that value as a weight to perform a weighted average. In this way, in the second modified example, the evaluation process takes into account the measurement sensitivity G corresponding to the position inside the measurement area K and evaluates the target surface X for each mesh M. Therefore, since the measurement sensitivity G of the measurement area K overlapping with the mesh M is taken into account when assigning measurement data, even more accurate measurement data can be obtained.

[0078] (Third variation) As shown in Figure 11, in the surface evaluation method according to the third modified example, the configuration of the positioning system 65 of the resistivity measuring device 60 differs from that of the positioning system 15 described above. The positioning system 65 is equipped with two GNSS antennas 66. The positioning system 65 calculates the direction of travel D1 from the relative positions of the two GNSS antennas 66. In this way, the positioning system 65 according to the third modified example can calculate the direction of travel D1, so the measurement area setting unit 54 can set the measurement area K taking into account the direction of travel D1 more appropriately. Note that the positioning system 65 according to the third modified example may be equipped with a GPS compass instead of the two GNSS antennas 66. In this case as well, the same effect as described above can be obtained.

[0079] (Fourth variation) In the surface evaluation method according to the fourth modified example, as shown in Figure 12, the positioning system calculates the position coordinates of measurement points P2 and P3 before and after a single measurement point P1, and calculates the direction of travel D1 from the rate of change of the calculated position coordinates. In this case as well, since the direction of travel D1 can be calculated by the positioning system, the measurement area setting unit 54 can more appropriately set the measurement area K taking into account the direction of travel D1.

[0080] (Fifth variation) Figure 13 is a perspective view showing a surface evaluation system 71 according to the fifth modified example. The surface evaluation system 71 is equipped with a plurality of measuring devices, which consist of a resistivity measuring device 10 and a dielectric constant measuring device 75. Furthermore, the surface evaluation system 71 is equipped with an embankment evaluation item calculation unit 82 that calculates the dry density of the embankment B and the water content of the embankment B.

[0081] The surface evaluation system 71 has a linear body 72 that connects the resistivity measuring device 10 and the dielectric constant measuring device 75 to each other. The dielectric constant measuring device 75 has a dielectric constant measuring unit 86, a running body 87, and a holding unit 88 that holds the dielectric constant measuring unit 86 while attached to the lower surface of the running body 87. The running body 87 has a plurality of wheels 87b and a base unit 87c provided on the upper part of the plurality of wheels 87b.

[0082] The holding portion 88 is attached to the lower surface of the base portion 87c with the relative permittivity measuring portion 86 held inside. The holding portion 88 is made of metal, for example. The holding portion 88 has a recess in which the relative permittivity measuring portion 86 is housed, and the lower surface of the recess is in contact with the embankment surface S. The relative permittivity measuring portion 86 measures the relative permittivity of the embankment B while in contact with the embankment surface S via the lower surface.

[0083] The permittivity measuring unit 86 measures the permittivity of the embankment B while facing the embankment B. The permittivity measuring unit 86 moves on the embankment surface S simultaneously with or immediately after the movement of the resistivity measuring device 10 to measure the permittivity. The permittivity measuring unit 86 is, for example, a ground-penetrating radar. In this case, the permittivity measuring unit 86 has a transmitting unit that transmits electromagnetic waves downward to the embankment B and a receiving unit that receives the electromagnetic waves. The permittivity measuring unit 86 measures the time from when the electromagnetic waves are irradiated until the electromagnetic waves return to the permittivity measuring unit 86.

[0084] The thickness of the construction layer of embankment B is measured in advance, and the dielectric constant measurement unit 86 calculates the velocity of electromagnetic waves from the above time and said thickness. The said thickness may be manually entered into the dielectric constant measurement unit 86, or layer thickness data measured by GNSS may be automatically entered into the dielectric constant measurement unit 86.

[0085] The relationship between the speed of electromagnetic waves and the relative permittivity is one-to-one. Therefore, the relative permittivity measurement unit 86 uses this relationship to calculate the relative permittivity from the speed of electromagnetic waves. For example, by obtaining the relationship between the relative permittivity and the volumetric water content of embankment B in advance through indoor testing, the surface evaluation system 71 uses this relationship to calculate the volumetric water content of embankment B from the relative permittivity. For example, the surface evaluation system 71 estimates the density and water content ratio of embankment B from the volumetric water content and resistivity of embankment B.

[0086] In the surface evaluation system 71, during the process of acquiring measurement data, the resistivity measuring device 10 acquires the resistivity of embankment B as measurement data, and the dielectric constant measuring device 75 acquires the dielectric constant as measurement data. Therefore, the dry density and water content of embankment B can be calculated from the resistivity and dielectric constant of embankment B. Consequently, the evaluation of embankment B can be performed with even greater accuracy.

[0087] In addition, a volumetric moisture content measuring device may be provided instead of the dielectric constant measuring device 75, and a scattering-type RI moisture meter may be provided instead of the dielectric constant measuring unit 86. In this case, the scattering-type RI moisture meter can measure the volumetric moisture content of the embankment B by irradiating fast neutron beams downward from the embankment surface S and detecting the thermal neutron beams that return after the fast neutron beams collide with the hydrogen atoms of the embankment B. In this case, since the volumetric moisture content of the embankment B can be measured by placing the scattering-type RI moisture meter on the embankment surface S, the moisture content of the embankment B can be measured easily and with high accuracy.

[0088] The embodiments and various modifications of the surface evaluation method and surface evaluation system described herein have been explained above. However, the surface evaluation method and surface evaluation system described herein are not limited to the embodiments or modifications described above, and can be modified as appropriate within the scope of the gist described in the claims. That is, the content and sequence of the steps of the surface evaluation method, as well as the configuration, shape, size, material, number and arrangement of each part of the surface evaluation system, are not limited to the embodiments or modifications described above, and can be modified as appropriate.

[0089] For example, in the embodiment described above, a peripheral mesh assignment unit 55 was described that assigns measurement data to all meshes M in which the measurement area K overlaps with the center N of the mesh M. However, measurement data may also be assigned to meshes M in which a position other than the center N of the mesh M overlaps with the measurement area K, and the conditions for which measurement data is assigned to meshes M can be changed as appropriate.

[0090] In the embodiments described above, an example was given in which the average value of resistivity was measured as measurement data. However, the measurement data is not limited to average values, and may also be measurement data in which uniform rejection or 1σ rejection of error values ​​has been performed, or measurement data obtained by a model that extracts representative values ​​from a group of measurement data using machine learning. Furthermore, the measurement data may also be measurement data other than resistivity, and as described above, the surface evaluation method and surface evaluation system 1 described above can also be applied to measurement data of dielectric constant or volumetric water content.

[0091] In the embodiments described above, examples were given in which both the single-mesh assignment method and the peripheral mesh distribution method are performed. However, depending on the situation, the single-mesh assignment method may be omitted. In this case, the single-mesh assignment section 52 may also be omitted. Furthermore, in the embodiments described above, an example was given in which the target surface X is a raised surface S. However, the target surface may be, for example, a concrete surface, and can be changed as appropriate. [Explanation of symbols]

[0092] 1…Surface evaluation system, 3…Linear body, 10…Resistivity measuring device (measuring device), 15…Positioning system, 20…Electrode, 21…Potential electrode, 22…Current electrode, 23…Dielectric, 24…Conductor, 25…AC power supply, 26…Voltmeter, 30…Tow unit, 30b…Wheel, 30c…Base unit, 30d…Handle unit, 31…Data acquisition unit, 41…Holder, 42…Caster, 43…Electrode holder, 46…Spring mechanism, 48…Linear body, 50…Surface evaluation application, 51…Mesh setting unit, 52…Single mesh assignment unit, 53…Evaluation unit, 54…Measurement area setting unit, 55…Peripheral mesh assignment unit, 60…Resistivity measuring device ,65...Positioning system, 66...GNSS antenna, 71...Surface evaluation system, 72...Linear body, 75...Relative permittivity measuring device, 82...Embankment evaluation item calculation unit, 86...Relative permittivity measuring unit, 87...Traveling body, 87b...Wheels, 87c...Base unit, 88...Holding unit, A...Site, B...Embankment, D1...Direction of travel, D2...Direction, D3...Orthogonal direction, E...Constant range, F...Area, G...Measurement sensitivity, K...Measurement area, K1...Long side, K2...Short side, M, M1, M2, M3, M4, M5, M6...Mesh, N...Center, P, P1, P2, P3...Measurement point, S...Embankment surface, T...Information terminal, T1...Display, X...Target surface, Y...Measurement range.

Claims

1. A surface evaluation method for evaluating a target surface that is the surface to be measured, The process involves moving the measuring device along the target surface and having the measuring device measure the target surface at regular intervals to acquire multiple measurement data, The process of associating each of the aforementioned measurement data with a measurement point, which is the location where the aforementioned measurement data was measured, using a positioning system. The steps include setting a mesh on the target surface, The steps include setting the measurement area as the region surrounding the measurement point on the target surface, A peripheral mesh assignment step involves assigning the measurement data to the mesh in which the measurement areas overlap, A step of evaluating the target surface for each mesh from the assigned measurement data, Equipped with, Surface evaluation method.

2. The process further comprises a single mesh assignment step of assigning the measurement data to the mesh including the measurement point, The process involves performing both the surrounding mesh assignment step and the single mesh assignment step, and then deleting either the measurement data assigned in the surrounding mesh assignment step or the measurement data assigned in the single mesh assignment step from the mesh to which the measurement data was assigned in both the surrounding mesh assignment step and the single mesh assignment step. The surface evaluation method according to claim 1.

3. In the aforementioned peripheral mesh assignment step, the measurement data is assigned to the mesh in which the measurement area overlaps with the center of the mesh. The surface evaluation method according to claim 1 or 2.

4. In the step of setting the measurement area, the measurement area is set according to the measurement sensitivity of the measuring device. The surface evaluation method according to claim 1 or 2.

5. In the step of setting the measurement area, the measurement area is set according to the direction of travel of the measuring device on the target surface. The surface evaluation method according to claim 1 or 2.

6. The aforementioned surface is a compacted raised surface. The surface evaluation method according to claim 1 or 2.

7. In the surrounding mesh allocation process, each time the measuring device performs the measurement, it calculates the area of ​​the region where the measurement area overlaps with the mesh. In the evaluation step described above, the value obtained by dividing the sum of the products of the ratio of the area of ​​the overlapping region to the area of ​​the mesh and the measurement data by the sum of the ratios is evaluated. The surface evaluation method according to claim 1 or 2.

8. In the evaluation step, the target surface is evaluated for each mesh, taking into account the measurement sensitivity of the measuring device according to its position within the measurement area. The surface evaluation method according to claim 1 or 2.

9. In the step of acquiring the measurement data, the measuring device acquires the resistivity of the embankment as the measurement data. The surface evaluation method according to claim 1 or 2.

10. In the step of acquiring the measurement data, one of the plurality of measuring devices acquires the resistivity of the embankment as the measurement data, and the other of the plurality of measuring devices acquires the dielectric constant as the measurement data. The surface evaluation method according to claim 1 or 2.

11. A surface evaluation system for evaluating a target surface that is the surface to be measured, A measuring device that moves along the target surface and measures the target surface at regular intervals to acquire multiple measurement data, A positioning system that associates each of the aforementioned measurement data with a measurement point which is the location where each of the aforementioned measurement data was measured, A mesh setting unit for setting a mesh on the target surface, A measurement area setting unit sets the measurement area as the region surrounding the measurement point on the target surface, A peripheral mesh assignment unit that assigns the measurement data to the mesh in which the measurement areas overlap, An evaluation unit that evaluates the target surface for each mesh based on the assigned measurement data, Equipped with, Surface evaluation system.

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