Thickness measurement device and thickness measurement method

Abstract

To enable measurement of the thickness of a coating layer formed on a construction surface such as a wall surface using a simple device without relying on the measurement skill of a measurer or using a laser scanner.SOLUTION: A thickness measurement device 10 for measuring the thickness of a coating layer 2 formed on a construction surface 1 includes a projection device 3, an imaging device 5, and a thickness estimation unit 7. The projection device 3 projects an image of a predetermined shape onto the construction surface 1 or a surface 2a of the coating layer 2 in a first direction D1 before and after construction to form the coating layer 2. The imaging device 5 captures an image of the construction surface 1 or the coating layer 2 from a second direction D2 intersecting with the first direction D1 before and after construction, and generates an image of the image. The thickness estimation unit 7 estimates the thickness of the coating layer 2 based on the amount of deviation between the position of the image in the pre-construction image and the position of the image in the post-construction image.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for measuring the thickness of a coating layer formed on a construction surface, such as a wall surface of a building, in construction or architecture. [Background technology]

[0002] 2. Description of the Related Art In the field of construction or architecture, there is a task of forming a layer of a predetermined material on a wall surface of a building by spraying the predetermined material on the wall surface, etc. There are various types of predetermined material, one example of which is a heat insulating material.

[0003] In such work, there are cases where it is necessary to control whether a coating layer of a specified material is applied to a specified thickness. In such cases, it is necessary to measure the thickness of the layer formed on the wall surface after application.

[0004] In the past, for example, after construction, before the material sprayed onto the wall surface hardened, the thickness of the layer was measured by inserting a rod-shaped member into the layer of the material and measuring the length of the material attached to the rod-shaped member with a ruler.

[0005] In addition, before and after the above-mentioned construction, three-dimensional coordinate data (three-dimensional point cloud data) of the wall is obtained using a laser scanner, and the thickness of the coating layer can be measured by comparing the three-dimensional coordinate data before and after construction (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2020-76585 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, when using a rod-shaped member, it is difficult to insert the rod-shaped member into the coating layer in a direction perpendicular to the wall. Also, the position where the material is attached on the rod-shaped member may not match the actual thickness of the coating layer. Also, there is a possibility that the thickness measurement value varies depending on the worker. For these reasons, it may not be possible to accurately measure the thickness of the coating layer using a rod-shaped member.

[0008] In addition, when a laser scanner is used, high-precision measurement is possible, but since a large amount of 3D point cloud data must be acquired and processed, the measurement may take a long time. In addition, laser scanners are expensive and costly.

[0009] Therefore, an object of the present invention is to provide an apparatus and method capable of measuring the thickness of a coating layer formed on a construction surface such as a wall surface using a simple device, without relying on the measurement skill of the person measuring, and without using a laser scanner. [Means for solving the problem]

[0010] In order to achieve the above object, a thickness measurement device according to the present invention is a device for measuring the thickness of a coating layer formed on a work surface, comprising: A projection device that projects an image of a predetermined shape onto the application surface or a surface of the coating layer in a first direction before and after the application to form the coating layer; An imaging device that captures an image of the construction surface or the coating layer from a second direction intersecting the first direction before and after the construction to generate an image of the image; The apparatus further includes a thickness estimation unit that estimates a thickness of the coating layer based on an amount of deviation between a position of the image in the image before application and a position of the image in the image after application.

[0011] In order to achieve the above object, a thickness measurement method according to the present invention is a method for measuring the thickness of a coating layer formed on a work surface, comprising the steps of: Before and after the application of the coating layer, an image of a predetermined shape is projected in a first direction onto the application surface or a surface of the coating layer; Before and after the application, the image on the application surface or the coating layer is captured from a second direction intersecting with the first direction to generate an image of the image; The thickness of the coating layer is estimated based on the amount of deviation between the position of the image in the image before application and the position of the image in the image after application. Effect of the Invention

[0012] According to the present invention, the thickness of a coating layer formed on a construction surface can be measured with a simple device, without relying on the measurement skill of the person measuring, and without using a laser scanner. [Brief description of the drawings]

[0013] [Figure 1] 1 illustrates a thickness measurement device according to an embodiment of the present invention. [Diagram 2] 1 shows an example of an image projected onto a construction surface. [Figure 3A] An example of an image with distortion is shown below. [Figure 3B] 4 shows another example of an image where image distortion occurs. [Figure 3C] 1 shows an example of an image in which image distortion has been corrected. [Figure 4] The before and after images are completely overlaid. [Diagram 5] 4 is a block diagram showing an example of the configuration of a thickness estimation unit. FIG. [Figure 6] 1 shows an image including a pre-construction image captured by an imaging device. [Figure 7] FIG. 4 is an explanatory diagram of a process for determining the thickness of a coating layer. [Figure 8] 4 is a flowchart illustrating a thickness measurement method according to an embodiment of the present invention. [Figure 9A] The figure shows the measurement error according to the position in the direction parallel to the line obtained by orthogonally projecting the optical axis of the imaging device onto the construction surface. [Figure 9B] This shows an image of the lattice shape in an image before construction. [Figure 10A] 4 shows an example of an error amount and a correction amount relating to the thickness measurement of a coating layer. [Figure 10B] 5 is an explanatory diagram of a method for setting a correction coefficient or a correction amount. FIG. [Figure 11] 1 shows a thickness measuring device according to a modified example. [Figure 12] 13 shows a thickness measuring device according to another modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. In the drawings, the same reference numerals are used to designate the same parts, and duplicated explanations will be omitted.

[0015] [First embodiment] (Configuration of thickness measurement device) FIG. 1 shows a thickness measuring device 10 according to an embodiment of the present invention. The thickness measuring device 10 measures the thickness of a coating layer 2 formed on a predetermined construction surface 1 of a building. Here, the construction surface 1 may be, for example, a wall surface, a floor surface, a ceiling surface, or a roof surface of a building. The construction surface 1 may be a surface facing the interior of a building, or a surface facing the exterior of a building (for example, an exterior wall surface of a building). The construction surface 1 may be a flat surface, or may be a curved surface. In FIG. 1, the direction perpendicular to the paper surface of this figure may be a vertical direction or a horizontal direction.

[0016] The coating layer 2 may be formed, for example, by spraying a predetermined material onto the construction surface 1, by applying a predetermined material onto the construction surface 1, or by other methods. The coating layer 2 may be a heat insulating layer. For example, the heat insulating layer may be formed by spraying a liquid heat insulating material as the predetermined material onto the construction surface 1. This heat insulating material may be, for example, a urethane resin to which a foaming agent (such as freon gas) has been added.

[0017] The thickness measurement device 10 includes a projection device 3, an imaging device 5, a distortion correction unit 6, and a thickness estimation unit 7.

[0018] The projection device 3 projects an image 4 of a predetermined shape (see FIG. 2 described later) in a first direction D1 onto the construction surface 1 before and after construction (hereinafter also simply referred to as construction) of forming the coating layer 2 on the construction surface 1. The first direction D1 may be, for example, a direction directly facing (orthogonal to) the construction surface 1, or a direction oblique to the construction surface 1.

[0019] The projection device 3 projects the image 4 onto the construction surface 1 so that the image 4 of the same shape and size is projected onto the same position on the construction surface 1 (in the case of construction, the construction surface 1 on the assumption that the coating layer 2 does not exist) before and after construction. More specifically, the projection device 3 projects the image 4 onto the construction surface 1 after construction (i.e., the surface 2a of the coating layer 2) so that the shape, size, and position of the image 4 projected by the projection device 3 onto the construction surface 1 after construction, on the assumption that the coating layer 2 had not been formed, are the same as the shape, size, and position of the image 4 projected before construction. For example, the position and orientation of the projection device 3 with respect to the construction surface 1 (the construction surface 1 not including the coating layer 2) are the same before and after construction, and the projection device 3 projects a projection light beam of the same cross-sectional shape onto the construction surface 1.

[0020] FIG. 2 is a view taken along the line II-II in FIG. 1, showing an example of the image 4 projected onto the construction surface 1. That is, FIG. 2 is a view of the construction surface 1 onto which the image 4 is projected by the projection device 3, seen from its normal direction. As in the example of FIG. 2, the predetermined shape of the image 4 projected onto the construction surface 1 by the projection device 3 may be a lattice shape. The lattice shape may be a shape in which a plurality of vertical lines spaced apart (for example, equally spaced) from one another and a plurality of horizontal lines spaced apart (for example, equally spaced) from one another intersect (for example, perpendicularly). According to the present invention, the image 4 projected onto the construction surface 1 is not limited to a lattice shape, and may have other shapes such as a rectangle or a triangle. It is preferable that the image 4 includes a portion having a predetermined length when projected onto the construction surface 1.

[0021] The imaging device 5 captures an image 4 of the construction surface 1 from a direction intersecting with the first direction D1 before and after construction to generate an image of the image 4. The position and orientation of the imaging device 5 with respect to the construction surface 1 (the construction surface 1 not including the coating layer 2) are the same before and after construction. Hereinafter, the image of the construction surface 1 captured by the imaging device 5 before construction is also simply referred to as the pre-construction image, and the image of the coating layer 2 on the construction surface 1 captured by the imaging device 5 after construction is also simply referred to as the post-construction image.

[0022] The distortion correction unit 6 corrects the distortion of the image 4 with respect to a predetermined reference line L (see FIG. 3A, etc., described later) in each of the pre-construction image and the post-construction image. This reference line L may be a line coinciding with a line obtained by orthogonally projecting the optical axis of the imaging device 5 onto the construction surface 1 (hereinafter also simply referred to as the orthogonal projection line of the optical axis). Moreover, this reference line L may be a straight line passing through the center of the image 4. In the following, the pre-construction image and the post-construction image may be images whose distortion has been corrected by the distortion correction unit 6.

[0023] Figures 3A and 3B show examples of images in which distortion occurs in the image 4. When the direction perpendicular to the paper surface of Figure 1 is the vertical direction, Figure 3A shows an image in which the imaging device 5 in Figure 1 captures the lattice-shaped image 4 (image 4 in Figure 2) from an obliquely lower side, and Figure 3B shows an image in which the imaging device 5 in Figure 1 captures the lattice-shaped image 4 (image 4 in Figure 2) from an obliquely upper side.

[0024] In Figures 3A and 3B, the image 4 projected onto the construction surface 1 is captured by the imaging device 5 from diagonally below or above, resulting in a vertical distortion with respect to a reference line L (dashed line in Figures 3A and 3B) extending horizontally in the image.

[0025] The distortion correction unit 6 corrects the distortion of the image 4 in Fig. 3A or 3B to produce an image with no (or reduced) distortion as shown in Fig. 3C. The distortion correction unit 6 may perform distortion correction using an affine transformation, for example. In this case, the distortion correction unit 6 does not need to perform image enlargement and reduction processing.

[0026] The thickness estimation unit 7 estimates the thickness of the coating layer 2 at a predetermined measurement point based on the amount of shift d between the position of the image 4 in the image of the construction surface 1 and the position of the image 4 in the image after construction (hereinafter also simply referred to as the amount of shift in the image). Here, the predetermined measurement point may be a recognizable point in the image 4 projected onto the construction surface 1 (for example, an intersection of multiple lines constituting the image 4, a corner of a predetermined shape of the image 4, etc.). In the case of a lattice-shaped image 4, the predetermined measurement point may be an intersection (lattice point) of multiple lines (for example, vertical and horizontal lines) constituting the lattice shape. Hereinafter, the predetermined measurement point may also be simply referred to as a measurement point.

[0027] The amount of deviation in the images will be explained in more detail. When the image before construction and the image after construction are superimposed so that the outer edges of both images completely match, the length from a specific point (e.g., a measurement point or a point nearby) of the image 4 in the image before construction to the same specific point of the image 4 in the image after construction may be the amount of deviation in the images. In the case of the image 4 having a lattice shape, the specific point may be a lattice point or a line segment connecting adjacent lattice points. The amount of deviation in the images may be represented by the number of pixels of the superimposed images.

[0028] FIG. 4 is a diagram for explaining the shift amount d in the image when the image 4 has a lattice shape, and shows the state in which the image before construction and the image after construction are completely overlapped as described above. In FIG. 4, only the outer edge of the lattice-shaped image 4 is shown. In FIG. 4, the symbol E indicates the outer edge of the image before construction and the outer edge of the image after construction, and both outer edges are completely overlapped. In FIG. 4, the symbol 4a indicates the outer edge of the lattice-shaped image 4 projected onto the surface 2a of the coating layer 2, and the symbol 4b indicates the outer edge of the lattice-shaped image 4 projected onto the construction surface 1 before construction.

[0029] When the coating layer 2 is formed on the application surface 1, the position of the image 4 projected on the coating layer 2 in the actual three-dimensional space is shifted in the projection direction (first direction) of the projection device 3 from the position of the image 4 projected on the application surface 1 by the thickness of the coating layer 2. Therefore, when the image before application and the image after application are completely superimposed, as shown in FIG. 4, a specific point (e.g., a lattice point) of the image 4 in the image before application and the same specific point of the image 4 in the image after application are shifted from each other. This shift amount d may be a component of the shift amount in a direction parallel to the orthogonal projection line of the optical axis, or may be the distance between the corresponding specific points in the image before application and the image after application superimposed on each other as described above. Note that FIG. 4 shows the shift amount d on the side closest to the imaging device 5 in the lattice shape of the image 4 in the image.

[0030] 5 is a block diagram showing an example of the configuration of the thickness estimation unit 7. The thickness estimation unit 7 includes a positional deviation specification unit 7a, an angle specification unit 7b, and a thickness calculation unit 7c.

[0031] The positional deviation specifying unit 7a receives the pre-construction image and the post-construction image from the imaging device 5 (eg, via the distortion correcting unit 6), and superimposes the two images on each other as described above to determine the amount of deviation d in the images.

[0032] Further, the positional deviation identifying unit 7a determines an actual deviation Δx corresponding to the determined deviation d on the image. For example, the positional deviation identifying unit 7a may determine the actual deviation Δx based on a ratio c of an actual length corresponding to a unit length in the image (e.g., one pixel) relative to the unit length, and the deviation d in the image. This actual deviation Δx is Δx=c·d. Here, c is the above-mentioned ratio, and may be, for example, a resolution (mm / pixel) indicating an actual length corresponding to one pixel relative to the dimension of the pixel in the image.

[0033] Here, the ratio c may be obtained in advance and stored in the positional deviation identifying unit 7a. The ratio c may be obtained in advance, for example, by the ratio calculation unit 7d based on the dimensions of a predetermined portion of the image 4 projected onto the image before construction as described above and the actual dimensions of the predetermined portion on the construction surface 1, and may be input to and stored in the positional deviation identifying unit 7a. The ratio calculation unit 7d may be a component of the thickness estimation unit 7. The ratio may be input to the positional deviation identifying unit 7a by a person using an appropriate input device instead of the ratio calculation unit 7d. The calculation of the ratio will be described in more detail in the thickness measurement method described later.

[0034] The process of the angle identification unit 7b will be described with reference to FIG. 1 and FIG. 6. FIG. 6 shows an image taken by the imaging device 5 before construction (or after construction). The angle identification unit 7b obtains an angle θ (see FIG. 1) between the normal vector of the construction surface 1 at the measurement point on the construction surface 1 and the line segment connecting the measurement point and the imaging device 5 (for example, the center of the imaging element of the imaging device 5 or the lens closest to the construction surface 1) based on the dimensions of the two comparison parts in the image 4 on the image before construction (or after construction). The two comparison parts in the image 4 are the measurement point and the reference point, respectively. The measurement point and the reference point are located at different positions in the direction parallel to the optical axis (the orthogonal projection line of the optical axis) obtained by orthogonally projecting the optical axis of the imaging device 5 onto the construction surface 1 (the left-right direction in FIG. 6). The two comparison parts have the same actual dimensions on the construction surface 1, but have different dimensions in the image taken obliquely with respect to the construction surface 1. When the image 4 has a lattice shape, each comparison portion may be, for example, a line segment connecting adjacent lattice points as shown in FIG. 6 (a line segment surrounded by a dashed line in FIG. 6).

[0035] The angle identification unit 7b obtains an index value indicating the difference in size between the two comparison parts in an image (for example, an image before construction) based on the image. This index value may be the difference or ratio between the size of the comparison part at the measurement point and the size of the comparison part at the reference point.

[0036] The angle identifying unit 7b determines the angle θ at the measurement point based on the determined index value and the relationship between the index value and the angle. Here, the relationship may be determined in advance and may be stored in the angle identifying unit 7b. Note that, without providing the angle identifying unit 7b, a person may determine the angle θ using an appropriate measuring device and store the determined angle θ in the thickness calculating unit 7c in advance.

[0037] The thickness calculation unit 7c calculates the thickness of the coating layer 2 at the measurement point based on the above-mentioned actual amount of deviation Δx determined by the positional deviation determination unit 7a and the above-mentioned angle θ determined by the angle determination unit 7b.

[0038] Fig. 7 is an explanatory diagram of a process for determining the thickness t of the coating layer 2, and is a partially enlarged diagram of Fig. 1. The thickness calculation unit 7c may calculate the thickness of the coating layer 2 by the following formula (E1). t = Δx / sinθ (E1) Here, the meanings of the symbols in the formula are as follows: t is the thickness of the coating layer 2 at the measurement point. Δx is the above-mentioned actual deviation amount at the measurement point. θ is the above-mentioned angle at the measurement point. The angle θ is less than 180 degrees. These t, Δx, and θ may be those shown in FIG.

[0039] The thickness estimation unit 7 (positional deviation identification unit 7a, angle identification unit 7b, thickness calculation unit 7c, and ratio calculation unit 7d) and the distortion correction unit 6 may be configured by a computer and a program that causes the computer to function as the thickness estimation unit 7 (positional deviation identification unit 7a, angle identification unit 7b, thickness calculation unit 7c, and ratio calculation unit 7d) and the distortion correction unit 6. That is, the program may cause the computer to execute the above-mentioned processing performed by each unit (positional deviation identification unit 7a, angle identification unit 7b, thickness calculation unit 7c, and ratio calculation unit 7d) and the distortion correction unit) of the thickness estimation unit 7. The data (image, ratio, etc.) required for the above-mentioned processing of the thickness estimation unit 7 and the distortion correction unit 6 and the above-mentioned program may be stored in a storage device of the computer.

[0040] (Thickness measurement method) 8 is a flowchart showing a thickness measurement method according to an embodiment of the present invention. This thickness measurement method may be performed using the above-described thickness measurement device 10. The thickness measurement method includes steps S1 to S10.

[0041] In step S1, the projection device 3 projects an image 4 of a predetermined shape onto the construction surface 1 before construction in a first direction D1. In one example, the predetermined shape of the image 4 projected onto the construction surface 1 at this time is a lattice shape as shown in Fig. 2. In this case, as shown in Fig. 2, a plurality of vertical lines and a plurality of horizontal lines constituting the lattice shape of the image 4 on the construction surface 1 may be perpendicular to each other.

[0042] In step S2, the actual dimensions of a predetermined portion of the image 4 projected onto the construction surface 1 in step S1 are measured. This predetermined portion may be located at a measurement point. If the image 4 has a lattice shape, this predetermined portion may be a line segment connecting adjacent lattice points in the image 4 (the portion surrounded by a dashed line in FIG. 2). In addition, the actual dimensions of the predetermined portion may be, for example, a dimension in a direction perpendicular to the orthogonal projection line of the optical axis (the vertical direction in FIG. 2), or a dimension in a direction parallel to the orthogonal projection line of the optical axis.

[0043] The measurement in step S2 may be performed using an appropriate device or instrument (for example, a ruler). The measurement value in step S2 may be input to the ratio calculation unit 7d by a person using an appropriate input device, for example.

[0044] In step S3, the image 4 projected onto the construction surface 1 in step S1 is captured in the second direction D2 by the imaging device 5. Also in step S3, distortion of the image 4 in the image is corrected by the distortion correction unit 6. In the following, the pre-construction image generated in step S3 may be an image in which distortion has been corrected in this way.

[0045] In step 4, the ratio calculation unit 7d calculates a ratio c of the actual dimension corresponding to the unit length in the image to the unit length in the image based on the dimension of the predetermined portion of the image 4 in the pre-construction image generated in step S3 and the actual dimension of the predetermined portion of the image 4 measured in step S2. The ratio calculation unit 7d inputs the calculated ratio c to the positional deviation identification unit 7a.

[0046] In step S5, the angle identifying unit 7b determines, based on the image generated in step S3, the angle θ between the normal vector of the construction surface 1 at the measurement point on the construction surface 1 and the line segment connecting the measurement point and the imaging device 5. That is, as described above, the angle identifying unit 7b determines, in the image generated in step S2, an index value indicating the difference in dimensions between comparison portions of the image 4 at different measurement points and a reference point, and determines the angle θ based on the relationship between the index value and the angle θ formed by the index value.

[0047] Although steps S4 and S5 are performed in this order in FIG. 8, they may be performed in the reverse order or in parallel.

[0048] In step S6, the coating layer 2 is formed on the application surface 1.

[0049] In step S7, the projection device 3 again projects an image 4 of a predetermined shape onto the treatment surface 1, that is, onto the coating layer 2 formed on the treatment surface 1, in the first direction D1.

[0050] In step S8, the image 4 projected onto the coating layer 2 on the construction surface 1 in step S4 is captured again in the second direction D2 by the imaging device 5. Also in step S8, distortion of the image 4 in the image is corrected by the distortion correction unit 6. In the following, the post-construction image generated in step S8 may be an image in which distortion has been corrected in this way.

[0051] In steps S1 and S7, the projection device 3 projects an image 4 onto the surface 2a of the construction surface 1 or the coating layer 2 so as to project an image 4 of the same size and shape to the same position or range on the construction surface 1 (construction surface 1 not including the coating layer 2) in the same first direction D1 from the same position relative to the construction surface 1. The position and orientation of the projection device 3 may be fixed from the start of step S1 to the end of step S7.

[0052] In addition, in steps S3 and S8, the imaging device 5 captures the same range including the image 4 projected onto the construction surface 1 or the surface 2a of the coating layer 2 in the same second direction D2 from the same position with respect to the construction surface 1. From the start of step S3 to the end of step S8, the position and orientation of the imaging device 5 may be fixed.

[0053] Before the start of step S1, the projection device 3 and the imaging device 5 may be arranged so that the image 4 projected by the projection device 3 on the construction surface 1 in the first direction D1 can be captured by the imaging device 5 in the second direction D2. In this arrangement, the optical axis of the projection device 3 and the optical axis of the imaging device 5 may intersect with each other (for example, on the construction surface 1). This arrangement may be fixed until the end of step S8.

[0054] In step S9, the positional deviation identifying unit 7a determines the amount of deviation d between the position of the image 4 in the pre-construction image generated in step S3 and the position of the image 4 in the post-construction image generated in step S8, as described above. Here, the position of the image 4 in the pre-construction image and the position of the image 4 in the post-construction image are the same position on the image 4. In addition, the position of the image 4 in the pre-construction image is a position corresponding to the measurement point on the construction surface 1 (for example, the position of the measurement point or a position near the measurement point).

[0055] In addition, in step S9, the positional deviation specifying unit 7a determines an actual deviation Δx (=c·d) corresponding to the deviation d, based on the determined deviation d and the ratio c determined in step S4.

[0056] In step S10, based on the angle θ calculated in step S5 and the actual deviation Δx calculated in step S9, the thickness calculation unit 7c calculates the thickness t of the coating layer 2 at the measurement point on the construction surface 1. The thickness calculation unit 7c may output the calculated thickness t to a display or storage device (not shown) so that the thickness t is displayed on the display or stored in the storage device. The display and the storage device may be components of the computer described above.

[0057] (Effects of the first embodiment) According to this embodiment, before and after construction to form the coating layer 2, the projection device 3 projects an image 4 of a predetermined shape onto the construction surface 1 or the surface 2a of the coating layer 2 in the first direction D1. In addition, before and after construction, the image 4 on the construction surface 1 or the coating layer 2 is captured by the imaging device 5 from the second direction D2 intersecting with the first direction D1 to generate an image of the image 4. The thickness estimation unit 7 estimates the thickness of the coating layer 2 based on the amount of deviation d between the position of the image 4 in the image before construction and the position of the image 4 in the image after construction. Therefore, the thickness of the coating layer 2 formed on the construction surface 1 can be measured by a simple device such as the projection device 3 and the imaging device 5 without relying on the measurement skill of the measurer or using a laser scanner.

[0058] More specifically, the thickness estimation unit 7 has a positional deviation identification unit 7a that determines an actual deviation amount Δx corresponding to the deviation amount d in the image. The thickness estimation unit 7 also has a thickness calculation unit 7c that calculates the thickness of the coating layer 2 at a measurement point based on the angle θ between the normal vector of the construction surface 1 at the measurement point and the line segment connecting the measurement point and the imaging device 5, and the actual deviation amount Δx at the measurement point. With this configuration, the thickness of the coating layer 2 can be determined.

[0059] Moreover, the positional deviation specifying unit 7a can obtain the actual amount of deviation Δx based on the ratio c of the actual dimension of the unit length to the unit length in the image and the amount of deviation d in the image.

[0060] The thickness calculation unit 7c calculates the thickness t of the coating layer 2 by t = Δx / sinθ. Therefore, the amount of processing required to obtain the thickness t of the coating layer 2 can be reduced compared to the case of processing three-dimensional point cloud data obtained by a laser scanner.

[0061] Moreover, the distortion correction unit 6 corrects the distortion of the image 4 with respect to a predetermined reference line L in each of the pre-construction image and the post-construction image, and the positional deviation identification unit 7a calculates the amount of deviation based on the images before and after construction in which the distortion of the image 4 has been corrected. This makes it possible to calculate the amount of deviation with high accuracy.

[0062] [Second embodiment] Next, a thickness measurement device 10 according to a second embodiment of the present invention will be described. Regarding the second embodiment, matters that are not described below may be the same as those in the first embodiment.

[0063] In the first embodiment, the thickness of the coating layer 2 was obtained at one measurement point on the application surface 1, but in the second embodiment, it is possible to obtain the thickness of the coating layer 2 at multiple measurement points on the application surface 1. That is, in the second embodiment, steps S1 to S10 of the thickness measurement method of the first embodiment described above are also performed in the above-mentioned order, but the above-mentioned steps S2, S4, S5, S9, and S10 may be performed for each of the multiple measurement points. In the following, i (and the suffix i of each symbol) means an identifier (e.g., a number) of the measurement point. For example, if there are 9 measurement points, i takes the value of a natural number from 1 to 9.

[0064] In step S2, actual dimensions of a plurality of predetermined portions of the image 4 projected onto the processing surface 1 in step S1 are measured. These predetermined portions may be located at a plurality of measurement points i (=1 to 9), respectively.

[0065] In step 4, for each of the plurality of predetermined portions in the image 4, the ratio calculation unit 7d calculates a ratio of the actual dimension corresponding to the unit length in the image to the unit length in the image based on the dimension of the predetermined portion in the image 4 before construction generated in step S3 and the actual dimension of the predetermined portion in the image 4 measured in step S2, as a ratio c i is required.

[0066] In step S5, the angle identifying unit 7b obtains a representative value θ0 of an angle between a normal vector of the construction surface 1 at a measurement point on the construction surface 1 and a line segment connecting each measurement point i and the imaging device 5, based on the image generated in step S3. This representative value may be the angle θ for any one of the measurement points i. Alternatively, this representative value may be an average value of the multiple angles θ for each of the multiple measurement points i.

[0067] In step S9, the positional deviation specifying unit 7a determines, for each of the plurality of measurement points i, a deviation amount d between a position corresponding to the measurement point i in the image 4 of the pre-construction image generated in step S3 and a position of the image 4 in the post-construction image generated in step S8.i Here, the position corresponding to the measurement point in the image before construction and the position of the image 4 in the image after construction are the same position in the image 4.

[0068] In step S9, the positional deviation specifying unit 7a calculates the deviation amount d i and the ratio c calculated in step S4 i Based on this, the deviation amount d i The actual deviation Δx corresponding to i (=c i d i ) is required.

[0069] In step S10, for each measurement point i, the representative value θ0 of the angle obtained in step S5 and the actual deviation amount Δx obtained in step S9 are i Based on this, the thickness t of the coating layer 2 at the measurement point i on the construction surface 1 is calculated. i Request.

[0070] More specifically, the thickness calculation unit 7c calculates the thickness of the coating layer 2 at each of multiple measurement points i on the construction surface 1 that are at different distances from the imaging device 5, using the following equation (E2) instead of the above-mentioned equation (E1). t i =Δx i / sinθ0···(E2) Here, t i = is the thickness of the coating layer 2 at the measurement point i. Δx i is the above-mentioned actual deviation amount at the measurement point i, which was obtained in step S9. θ0 is a representative value of the angles formed by the multiple measurement points and was determined in step S5.

[0071] (Effects of the second embodiment) According to this embodiment, the thickness t of the coating layer 2 at a plurality of measurement points i i In particular, the thickness t of the coating layer 2 at a plurality of measurement points i can be obtained by performing the above-mentioned steps S1 to S10 only once.i In addition, it is no longer necessary to calculate the angle θ for each measurement point i.

[0072] [Third embodiment] Next, a thickness measurement device 10 according to a third embodiment of the present invention will be described. Regarding the third embodiment, matters that are not described below are the same as those in the second embodiment.

[0073] In the second embodiment described above, in step S5, a representative value θ0 of the angle θ formed with respect to the multiple measurement points i is obtained. In the third embodiment, in step S3, the angle θ i Request.

[0074] That is, in the third embodiment, in step S5, the angle specifying unit 7b determines, for each measurement point i, an angle θ between the normal vector of the construction surface 1 at the measurement point i and the line segment connecting the measurement point i and the imaging device 5 based on the pre-construction image generated in step S2. i Request.

[0075] In the third embodiment, in step S10, the angle θ i and the actual deviation amount Δx calculated in step S9. i Based on this, the thickness t of the coating layer 2 at the measurement point i on the construction surface 1 is calculated. i Request.

[0076] More specifically, the thickness calculation unit 7c calculates the thickness of the coating layer 2 at each of multiple measurement points i on the construction surface 1 that are at different distances from the imaging device 5, using the following equation (E3) instead of the above-mentioned equation (E2). t i =Δx i / sinθ i (E3) Here, θ いis the angle θ at the measurement point i, which was calculated in step S5. The meanings of the other symbols in formula (E3) are the same as in the second embodiment.

[0077] (Effects of the third embodiment) In this embodiment, the angle θ i Therefore, the angle θ corresponding to the measurement point i is calculated. i The difference in thickness t i Other effects of this embodiment are similar to those of the second embodiment.

[0078] [Fourth embodiment] Next, a thickness measurement device 10 according to a fourth embodiment of the present invention will be described. Regarding the fourth embodiment, matters that are not described below may be the same as those in the first, second, or third embodiment.

[0079] FIG. 9A shows the measurement error according to the position in the direction parallel to the orthogonal projection line of the optical axis on the construction surface 1 (the line obtained by orthogonally projecting the optical axis of the imaging device 5 onto the construction surface 1). The horizontal axis of FIG. 9A indicates the position on the construction surface 1 in the direction parallel to the orthogonal projection line of the optical axis. That is, the numbers 1 to 9 on the horizontal axis of FIG. 9A indicate the positions (measurement points) of the vertical lines marked with the numbers 1 to 9 in the lattice-shaped image 4 in the pre-construction image shown in FIG. 9B. The direction of the horizontal axis in FIG. 9A (right side) indicates the side farther from the imaging device 5.

[0080] The vertical axis of Fig. 9A indicates the error in the thickness of the coating layer 2 obtained at each measurement point i (the measurement points numbered 1 to 9 on the horizontal axis of Fig. 9A) by the above-mentioned third embodiment when a coating layer 2 having a thickness of 10 cm is actually formed on the construction surface 1 (wall surface). Each of the data (1) to (5) in Fig. 9A indicates the error data at the positions of the horizontal lines numbered (1) to (5) in the lattice-shaped image 4 in the pre-construction image shown in Fig. 9B.

[0081] The closer the measurement point i is to the imaging device 5 on the construction surface 1, the smaller the angle θ ibecomes smaller, so that there is a tendency for the error in the thickness of the covering layer 2 calculated by the above formula (E1), (E2), or (E3) to become larger, as shown in FIG. 9A.

[0082] Therefore, in this embodiment, in step S10, the thickness of the coating layer 2 at the measurement point i on the processing surface 1 is calculated by the following formula (E4) instead of the above-mentioned formula (E1), (E2), or (E3). t i =Δx i ·w i / sinθ i (E4) Here, w i is the correction coefficient for measurement point i. i is, for example, a positive number smaller than 1, and is set so as to become smaller as the measurement point i is closer to the imaging device 5 in the direction parallel to the orthogonal projection line of the optical axis on the construction surface 1. i may be calculated in advance and stored in the thickness calculation unit 7c. The meanings of the other symbols in formula (E4) are the same as those in the third embodiment.

[0083] In one example, if the image 4 has a lattice shape, w i may be expressed by the following formula (E5): w i = L(0) / L(i) (E5) Here, L(0) is the distance between adjacent lattice points at a fixed point (e.g., the position farthest from the imaging device 5) in the lattice shape of the image 4 in the image before construction. L(i) is the distance between adjacent lattice points at the position of the measurement point i in the lattice shape of the image 4 in the image before construction.

[0084] Alternatively, a correction amount (correction curve) as shown in Fig. 10 described later may be set in advance based on an experimentally obtained error as shown in Fig. 9A. In this case, in this embodiment, in step S10, the thickness of the coating layer 2 at the measurement point i on the construction surface 1 is calculated by the following formula (E6) instead of the above formula (E4). t i =(Δx i / sinθ i )-α i (E6) Here, α i is the correction amount for measurement point i. i may be calculated in advance and stored in the thickness calculation unit 7c. The meanings of the other symbols in formula (E6) are the same as those in the third embodiment.

[0085] FIG. 10A shows the error amount and the correction amount α i 9A, the horizontal axis indicates the position of measurement point i on the construction surface 1 in a direction parallel to the orthogonal projection line of the optical axis. The numbers 1 to 9 on this horizontal axis indicate the distance from the imaging device 5. The vertical axis of FIG. 10A indicates the amount of error or the amount of correction estimated in advance. In FIG. 10A, the dashed curve indicates the amount of error estimated in advance, and the solid curve indicates the amount of correction for the estimated error. In this example, both curves are symmetrical with respect to the horizontal axis.

[0086] As shown in FIG. 10A, the correction amount α i is set according to the position of the measurement point i in the direction parallel to the orthogonal projection line of the optical axis. i is equal to the estimated value of the error at measurement point i.

[0087] FIG. 10B shows the correction coefficient w i Or the correction amount α i FIG. 1 is an explanatory diagram of a method for setting the correction coefficient w i Or the correction amount α i can be obtained as follows. Steps S1 to S10 of the thickness measurement method of the second or third embodiment are experimentally performed. In this case, in step S6, instead of forming a coating layer 2 on the application surface 1, a calibration sheet 11 with a uniform thickness is attached to the application surface 1 as shown in FIG. 10B. The thickness of the calibration sheet 11 may be a desired value of the thickness of the coating layer 2 to be formed on the application surface 1.

[0088] In addition, in the experimental implementation of the thickness measurement method, the thickness t of the coating layer 2 is measured for each measurement point i in step S10. i Instead of the thickness t of sheet 11, i For each measurement point i, the thickness t of the sheet 11 is calculated. i and a correction factor w based on the actual thickness of sheet 11 i Or the correction amount α i may be calculated and set in the thickness calculation unit 7c.

[0089] (Effects of the fourth embodiment) According to this embodiment, a correction coefficient or correction amount whose value varies depending on the position of the measurement point in a direction parallel to the orthogonal projection line of the optical axis is set in response to a thickness measurement error of the coating layer 2 due to differences in the position in the direction. The thickness of the coating layer 2 is calculated using the correction coefficient or correction amount set in this way, so that errors due to differences in the positions of the measurement points can be eliminated or reduced.

[0090] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the technical concept of the present invention. For example, the thickness measurement device 10 according to the embodiment of the present invention does not need to have all of the above-described features, and may have only some of the above-described features.

[0091] In addition, in any of the above-mentioned first to fourth embodiments, the following modified example 1 or 2 may be adopted. In this case, matters that are not described below are the same as those described above.

[0092] (Change example 1) Fig. 11 shows a thickness measuring device 10 according to a first modified example. As shown in Fig. 11, the projection device 3 and the imaging device 5 are connected to each other by a connecting member 8 so that the imaging device 5 can capture an image 4 projected by the projection device 3 in a first direction D1 onto the construction surface 1 in a second direction D2. This connection may fix or make fixable the positions and orientations of the projection device 3 and the imaging device 5 relative to each other. The connection member 8 may be connected to each of the projection device 3 and the imaging device 5 using appropriate means (e.g., bolts, screws, etc.).

[0093] (Change example 2) Fig. 12 shows a thickness measurement device 10 according to Modification 2. As shown in Fig. 12, the projection device 3 and the imaging device 5 are integrated with each other so that the imaging device 5 can capture an image 4 projected by the projection device 3 in a first direction D1 onto the construction surface 1 in a second direction D2. Due to this integration, the positions and orientations of the projection device 3 and the imaging device 5 relative to each other may be fixed or fixable.

[0094] 12 , the thickness measurement device 10 includes a support 9 to which the projection device 3 and the imaging device 5 are attached and which supports the projection device 3 and the imaging device 5. The support 9 is common to the projection device 3 and the imaging device 5. For example, the support 9 may be a housing in which the imaging device 5 and the projection device 3 are attached, or may be a frame in which the imaging device 5 and the projection device 3 are attached.

[0095] In addition, the distortion correction unit 6 and the thickness estimation unit 7 (for example, the above-mentioned computer constituting the distortion correction unit 6 and the thickness estimation unit 7) may be attached to a support 9, or may be attached, for example, inside a housing. [Explanation of symbols]

[0096] 1 Construction side 2 Covering layer 2a Surface of the coating layer 3 Projection device 4 statues 5. Imaging device 6 Distortion correction section 7 Thickness Estimation Section 7a Position deviation identification unit 7b Angle specific part 7c Thickness calculation section 7d Ratio calculation section 8 Connecting members 9 Support 10 Thickness measuring device D1 1st direction (projection direction) D2 Second direction (imaging direction) L reference line

Claims

1. A thickness measuring device for measuring the thickness of a coating layer formed on a work surface, a projection device that projects an image of a predetermined shape onto the application surface or a surface of the coating layer in a first direction before and after application to form the coating layer; an imaging device that captures an image of the construction surface or the coating layer from a second direction intersecting the first direction before and after the construction to generate an image of the image; A thickness measuring device comprising: a thickness estimation unit that estimates the thickness of the coating layer based on the amount of deviation between the position of the image in the image before the application and the position of the image in the image after the application.

2. The thickness measurement device according to claim 1 , wherein the predetermined shape is a lattice shape.

3. The thickness estimation unit estimates the thickness of the coating layer at a predetermined measurement point on the construction surface, a positional deviation specifying unit for determining an actual amount of deviation corresponding to the amount of deviation at the measurement point in the image; 2. The thickness measuring device according to claim 1, further comprising: a thickness calculation unit that calculates a thickness of the coating layer at the measurement point based on a normal vector of the construction surface at the measurement point, an angle between the measurement point and a line segment connecting the measurement point and the imaging device, and the actual amount of deviation at the measurement point.

4. 4. The thickness measurement device of claim 3, wherein the positional deviation identifying unit determines the amount of deviation in the image based on the images before and after the construction, and determines the actual amount of deviation based on the amount of deviation and a ratio of an actual dimension of the unit length to the unit length in the image.

5. The second direction is a direction oblique to the construction surface, The thickness calculation unit calculates the thickness of the coating layer at the measurement point by the following formula: t=Δx / sinθ 4. The thickness measurement device of claim 3, wherein t is the thickness of the coating layer at the measurement point, Δx is the actual shift amount at the measurement point, and θ is the angle at the measurement point.

6. The second direction is a direction oblique to the construction surface, The thickness calculation unit calculates a thickness of the coating layer at at least one of the plurality of measurement points on the construction surface that are at different distances from the imaging device by the following formula: t ｉ =Δx ｉ / sinθ ｉ Here, i is the identifier of the measurement point, t is the thickness of the coating layer at the measurement point i, and Δx ｉ is the actual deviation amount at the measurement point i, and θ ０ The thickness measurement device according to claim 3 , wherein x is a representative value of the angles formed by each of the plurality of measurement points.

7. The second direction is a direction oblique to the construction surface, The thickness calculation unit calculates a thickness of the coating layer at at least one of the plurality of measurement points on the construction surface that are at different distances from the imaging device by the following formula: t ｉ =Δx ｉ ・w ｉ / sinθ ｉ Here, i is the identifier of the measurement point, and t ｉ is the thickness of the coating layer at the measurement point i, and Δx ｉ is the actual deviation amount at the measurement point i, and θ ｉ is the angle at the measurement point i, and w ｉ The thickness measurement device according to claim 3 , wherein x i is a correction coefficient for the measurement point i.

8. The second direction is a direction oblique to the construction surface, The thickness calculation unit calculates a thickness of the coating layer at at least one of the plurality of measurement points on the construction surface that are at different distances from the imaging device by the following formula: t ｉ =(Δ+ ｉ / synth ｉ )-a ｉ Here, i is the identifier of the measurement point, and t ｉ is the thickness of the coating layer at the measurement point i, and Δx ｉ is the actual deviation amount at the measurement point i, and θ ｉ is the angle at the measurement point i, and α ｉ The thickness measurement device according to claim 3 , wherein: is a correction amount for the measurement point i.

9. 4. The thickness measurement device according to claim 3, wherein the thickness estimation unit calculates an index value indicating the difference between a dimension of the comparison portion of the image at the measurement point in the image and a dimension of the comparison portion of the image at a reference point in the image, calculates the angle at the measurement point based on the relationship between the index value and the angle, and inputs the calculated angle to the thickness calculation unit.

10. A distortion correction unit is provided to correct image distortion in each of the pre-construction image and the post-construction image, The thickness measurement device according to claim 4 , wherein the positional deviation specifying unit determines the amount of deviation based on the images before and after the application in which the image distortion has been corrected.

11. 2. The thickness measurement device according to claim 1, wherein the projection device and the imaging device are integrated with each other or connected by a connecting member so that the image projected by the projection device in the first direction onto the construction surface can be captured by the imaging device in the second direction.

12. A thickness measurement method for measuring the thickness of a coating layer formed on a work surface, comprising: Before and after the application of the coating layer, an image of a predetermined shape is projected in a first direction onto the application surface or a surface of the coating layer; Before and after the application, the image on the application surface or the coating layer is captured from a second direction intersecting with the first direction to generate an image of the image; A thickness measurement method for estimating a thickness of the coating layer based on an amount of deviation between a position of the image in the image before application and a position of the image in the image after application.

Images