JP7664452B2 - Coating material thickness measurement method, coating material thickness measurement system, and coating material application method - Google Patents

Description

The present invention relates to a method for measuring the thickness of a coating material applied to a target surface such as a wall or floor of a building by a spraying method or the like, a system for measuring the thickness of the coating material, and a method for applying the coating material.

As a method for providing insulation on the walls of buildings, etc., a method is known in which an on-site worker uses a foaming machine to directly spray a foaming concentrate, which is a mixture of a main ingredient and a foaming material, onto the target surfaces of the building, such as the walls, floors, roofs, and ceilings, and foams and solidifies the foam. Since the insulating effect of this insulation material is greatly affected by its thickness, it is required to have a uniform thickness. In particular, in buildings and apartment buildings, it is required to provide uniform quality, and construction with a thickness error of 0 to 20 mm, and in the strictest case, 0 to 5 mm is required.
Therefore, after spraying the foaming material onto the target surface and letting it foam and harden, the thickness is checked, and if the area is too thick, the excess is cut off, and if the area is too thin, additional foaming material is sprayed on for finishing. In detail, while spraying is being done at the construction site, a needle-shaped measuring gauge is inserted into each part of the foamed and hardened insulation material to measure its thickness, and it is checked whether finishing is necessary in each part. For this reason, the construction of insulation material is one of the most tedious tasks for workers. Also, the work speed varies greatly depending on the skill level of the worker, and there is also variation in the quality.
Furthermore, in order to guarantee the quality of the insulation, reports to clients and the like have been made by inserting measuring gauges into various points on the construction site to check the thickness of the construction, marking the results (for example, the measured thickness value) on the surface of the insulation (wall), and presenting a photograph of a portion of that surface.
In this way, in order to check the thickness of the insulation from installation to reporting, it was necessary to insert the measuring gauge several times, which was cumbersome and could cause physical damage to the insulation. Furthermore, the thickness of the insulation could only be reported at discrete measurement points.

US Patent No. 5,399,633 discloses a method and a robot that includes a spray nozzle connected to a source of foam material and a sensing device configured to monitor the thickness of the coating. The method of US Patent No. 5,399,633 reduces finishing operations by controlling the amount of foam material sprayed while monitoring the spray thickness with a laser range finder.
Patent Document 2 discloses a remotely controlled robot arm equipped with a spray nozzle and a range finder at the tip. It is described that the range finder can be used to measure the material (target object) before and after application, and the thickness to be filled can be calculated.
The present applicant has proposed a method for measuring the thickness of a coating material applied to a target surface, as disclosed in Japanese Patent Application No. 2019-39920, which includes the steps of acquiring an application shape including three-dimensional coordinates of the surface of the coating material and reference three-dimensional coordinates of three or more points that are at known and equal distances from the target surface, calculating a virtual plane based on the acquired reference three-dimensional coordinates, and calculating the thickness of the coating material based on the three-dimensional coordinates of the surface of the coating material and the virtual plane.

Special table 2016-526121 publication Special table 2017-536976 publication

However, the method of Patent Document 1 is premised on the use of a robot, and the use of a robot is not necessarily advantageous at the work site. On the other hand, the method of Patent Document 1 can be performed by an operator, but since the thickness of the foam material sprayed is controlled while monitoring the thickness at all times with a laser distance meter instead of a measuring gauge, the operator still has to alternate between spraying and checking the thickness (checking the monitor), which makes the work complicated. For example, human errors such as misreading the monitor are likely to occur. Patent Document 2 also does not measure the entire material to be applied (target surface), but instead measures a part of the material to be applied (target surface) at all times, and has the same problems as Patent Document 1.
The method for measuring the thickness of the covering material proposed by the present applicant can easily measure the entire thickness of the applied covering material by comparing the virtual plane with each point of the covering material. However, the wall surface of a building, which is the target surface to which the insulating material is sprayed, is generally not a perfect plane. For example, due to the influence of the accuracy of the formwork when pouring concrete, there are unevenness and distortions (unevenness of the wall surface) of several mm on the wall surface. In this way, if the target surface itself is uneven, the virtual plane will not be parallel to the target surface, and an error will occur. In addition, as an example of a method for measuring the thickness of the covering material, the virtual plane is calculated using the head of a pin inserted into the covering material as the reference three-dimensional coordinate, but even in this case, the virtual plane may not be parallel to the target surface depending on the installation state of the pin (insertion direction). In addition, the three-dimensional coordinates and reference three-dimensional coordinates of the surface of the covering material are obtained by a three-dimensional measuring device, but the virtual plane may not be parallel to the target surface due to measurement errors of the three-dimensional measuring device. If the virtual plane and the target surface are not parallel in this way, an error will occur in the calculated thickness of the covering material. In particular, the error becomes large when the virtual plane is large, that is, when the virtual plane is located at a position far away from the reference three-dimensional coordinates used to calculate the virtual plane.
The present invention aims to provide a method for measuring the thickness of a coating material applied to a target surface such as a wall of a building, which is easy to measure the thickness of the coating material and has small measurement error even if the target surface is uneven, a coating material thickness measurement system, and a coating material application method.

The method for measuring the thickness of a coating material of the present invention is a method for measuring the thickness of a coating material applied to a target surface, and is characterized by comprising the steps of: acquiring an application shape including three-dimensional coordinates of the surface of the coating material and four or more reference three-dimensional coordinates whose distances from the target surface are known; calculating an estimated target surface shape by estimating the target surface based on the four or more reference three-dimensional coordinates; and calculating the thickness of the coating material based on the three-dimensional coordinates of the surface of the coating material and the estimated target surface shape.
In the present invention, the "thickness of the coating material" refers to the length in the direction perpendicular to the target surface. Furthermore, the "three-dimensional coordinates of the surface of the coating material" refers to the three-dimensional coordinates on the surface of the coating material exposed on the side of the space opposite the target surface. For example, it may be a set of three-dimensional coordinates of multiple points on the surface of the coating material. Furthermore, the "distance from the target surface" refers to the length of the perpendicular line drawn from the reference three-dimensional coordinates to the target surface.
The method of expressing three-dimensional coordinates is not particularly limited as long as it can be processed on a computer. For example, it may be expressed as a set of coordinate values in a three-dimensional orthogonal coordinate system of (X, Y, Z) (so-called point cloud data), or it may be expressed as a mathematical expression or parameter expression of a plane/curved surface such as a polygon mesh, or a volume data expression (voxel, etc.), or a combination of these.

The coating material thickness measurement method of the present invention calculates an estimated target surface shape by estimating the shape of the target surface based on the reference three-dimensional coordinates of four or more points whose distances from the target surface are known, so even if the target surface is uneven, the reference three-dimensional coordinates are inaccurate, or there is a measurement error in the three-dimensional measurement device, the effects can be minimized.

In the coating material thickness measurement method of the present invention, it is preferable that the estimated target surface shape is made up of a plurality of virtual planes calculated based on the reference three-dimensional coordinates of the four or more points.
In the coating material thickness measurement method of the present invention, it is preferable that each of the virtual planes is calculated based on the reference three-dimensional coordinates of at least three points among the four or more reference three-dimensional coordinates.
In the coating material thickness measuring method of the present invention, it is preferable that the thickness at each point on the surface of the coating material is calculated based on a virtual plane corresponding to each of the points among the plurality of virtual planes.
In the method for measuring the thickness of a coating material of the present invention, it is preferable that the multiple virtual planes are calculated so that their regions do not overlap.
The method for measuring the thickness of a coating material of the present invention preferably includes a step of placing a reference marker on or near the coating material prior to the step of acquiring the construction shape, and the reference three-dimensional coordinates are preferably three-dimensional coordinates on the reference marker.
The coating thickness measuring method of the present invention preferably includes a step of displaying an image of the coating material showing the distribution of the coating material thickness by color or shading.
The coating material thickness measuring method of the present invention preferably includes a step of determining whether or not there is a defective application location where the coating material thickness is outside a predetermined range.
The coating material thickness measuring method of the present invention preferably includes a step of displaying the defective application location on the coating material image.
In the method of measuring the thickness of a coating material of the present invention, it is preferable that the coating material is a sprayed urethane foam insulation material.

The coating material thickness measurement system of the present invention is a system for measuring the thickness of a coating material applied to a target surface, and is equipped with a three-dimensional measurement device and a data processing unit, the three-dimensional measurement device acquires an applied shape including the three-dimensional coordinates of the surface of the coating material and four or more reference three-dimensional coordinates whose distances from the target surface are known, the data processing unit calculates an estimated target surface shape by estimating the target surface based on the four or more reference three-dimensional coordinates, and calculates the thickness of the coating material based on the three-dimensional coordinates of the surface of the coating material and the estimated target surface shape.

The coating material application method of the present invention is a method for applying a coating material to a target surface, and is characterized by comprising the steps of: applying the coating material to the target surface; acquiring the three-dimensional coordinates of the surface of the coating material and four or more reference three-dimensional coordinates whose distances from the target surface are known; calculating an estimated target surface shape by estimating the target surface based on the four or more reference three-dimensional coordinates; calculating the thickness of the coating material based on the three-dimensional coordinates of the surface of the coating material and the estimated target surface shape; and judging whether there are any poorly applied areas where the thickness of the coating material is outside a predetermined range.

The present invention can accurately measure the thickness of the coating material applied to a target surface even if the target surface is uneven, the worker's work is inaccurate (e.g., the pin is inserted in the wrong direction), or there is a measurement error in the three-dimensional measuring device.

1 is a schematic diagram showing a configuration of an embodiment of a coating material thickness measurement system of the present invention. FIG. 2a is a flow chart showing an embodiment of a coating thickness measurement method of the present invention, and FIG. 2b is a flow chart showing a coating thickness calculation method thereof. FIG. 3a is a front view showing the construction shape, FIG. 3b is a cross-sectional view taken along line XX, and FIG. 3c is a perspective view showing the construction shape calculated from a virtual plane.

The coating material thickness measurement system 1 in FIG. 1 measures the thickness T of a coating material C applied to a target surface W, and includes a three-dimensional measurement device 10, a control unit 20, and a display unit 30. The coating material C has six (four or more) reference markers M whose distances from the target surface W are known.

The coating material measured by the thickness measurement method of the embodiment is applied to a target surface by a worker or the like at the site. Examples of the application method of the coating material include spraying and coating. In particular, coating materials applied by spraying are suitable for the coating material thickness measurement system 1 because it is more difficult to achieve a uniform thickness after application compared to coating.
Target surfaces (construction surfaces) include building walls, floors, roofs, ceilings, and rooftops, and the method is particularly useful for areas such as roofs and ceilings where thickness measurement is difficult.

Examples of covering materials include heat insulating materials, fireproofing materials, waterproofing materials, general building materials (FRP, FRC, FRG), etc. Examples of heat insulating materials include soft or rigid urethane foam, rock wool, cellulose fiber, etc. In particular, rigid urethane foam (such as rigid urethane foam specified in JIS A9526) that is foamed on site and applied by spraying is preferred. Sprayed urethane foam using potassium octylate or lead octylate has a high reaction rate, and the foaming liquid sprayed onto the target surface expands irregularly to a foaming ratio of about 20 to 120 times, making it difficult even for an experienced worker to apply it to a uniform thickness (about 10 to 200 mm), and the thickness of application directly affects the heat insulating performance. On the other hand, examples of waterproofing materials include urethane-based, FRP-based, acrylic rubber-based, and acrylic resin-based materials.

The reference marker M is a disk-shaped one, and as shown in FIG. 3b, it is provided on the head (upper end) of the pin N so that the top surface (flat part) of the disk is perpendicular to the pin N. By inserting the pin N into the covering material C so that it is perpendicular to the target surface W, the reference marker M (top surface) becomes parallel to the target surface W. In other words, the length of the perpendicular line drawn from the reference marker M to the target surface W is the distance L (the length of the pin N + the thickness of the reference marker M). Therefore, as described later, the three-dimensional coordinates of any point on the reference marker M can be set as the reference three-dimensional coordinates whose distance from the target surface is known. The length of the pin N is substantially the same as or slightly larger than the planned thickness of the covering material C. This prevents the reference marker M from being buried in the covering material C applied to the planned thickness.
Although the reference marker M is a disk-shaped one, it is not particularly limited, and examples thereof include a sphere, a cube, and a polygonal flat plate such as a triangle or a square. If the reference marker M has the geometric characteristics listed above, it is preferable because it is easy to automatically recognize by image processing. In addition, it is preferable to apply a color to the reference marker M that is easy to distinguish when the covering material C is used as the background. For example, by making the color of the reference marker M red, blue, green, etc. for a white or ivory covering material, it becomes easy to automatically recognize the reference marker M using the color characteristics as a clue.
The pins N supporting the reference marker M are not particularly limited. For example, the reference marker may be supported by three or more pins N. In this case, by bringing the tips of the three pins into contact with the target surface W, the three pins can be easily made perpendicular to the target surface W, and the operator can easily place the reference marker M at a predetermined distance from the target surface W.

Returning to FIG. 1, the three-dimensional measuring device 10 acquires a construction shape including three-dimensional coordinates of the surface of the coating material C and three-dimensional coordinates of the surface of a reference marker M provided on that surface.
Examples of the three-dimensional measuring device 10 include a three-dimensional scanner and a stereo camera. Three-dimensional scanners include those that apply laser light to a target surface and calculate the three-dimensional shape of the target surface using the reflected light (LIDAR method), and those that measure distance based on the time it takes for the irradiated light to be reflected and returned (TOF method). A handy three-dimensional scanner that employs either method is known, and that measures along the target surface, combines multiple images consisting of measurement areas for each part of the target surface, and acquires an overall image.
On the other hand, a stereo camera calculates a three-dimensional shape from images of a target surface captured by two cameras using the principle of triangulation, and there are methods that use a separate projector to project a measurement pattern to improve the matching accuracy of the two camera images, or replace one of the two cameras with a projector that projects a pattern light (active stereo method). Also, there are known handy stereo cameras that use the active stereo method and can capture images of a wide target surface at once.
Considering on-site use, a handy 3D scanner or a handy stereo camera is preferable. In particular, a handy 3D scanner is preferable because it can reduce the amount of data processing and shorten the time required to measure the 3D shape.
The method of expressing the construction shape is not particularly limited as long as it can be processed on a computer, but an example of this is three-dimensional data expressed as a set of coordinate values in a three-dimensional orthogonal coordinate system of (X, Y, Z) (so-called point cloud data).
It is also preferable to include color information of the target in the construction shape. For example, if a color camera is used for 3D measurement, color images can be acquired at the same time as 3D coordinates, and point cloud data with added color information can be generated. By adding color information in this way, it is possible to recognize the reference markers and covering material areas based on the color information of the construction shape data.

The control unit 20 includes a memory unit 21 and a data processing unit 22 that calculates the thickness of the coating material.
The storage unit 21 stores the construction shape acquired by the three-dimensional measuring device 10. It also stores the virtual plane and the thickness of the coating material calculated by the data processing unit 22 as described below. It also stores the three-dimensional coordinates of the surface of the coating material and the thickness of the coating material, particularly the coating material image, in association with the target surface W. It also stores various other necessary data.
The data processing unit 22 calculates an estimated target surface shape at a distance L from the target surface W based on the construction shape including the three-dimensional coordinates of the surface of the coating material acquired by the three-dimensional measuring device 10 and the three-dimensional coordinates of four or more reference markers M. Here, the estimated target surface shape is composed of multiple virtual planes (references V1 to V4 in FIG. 3c). The estimated target surface shape is an approximation of the shape of the target surface W including unevenness using multiple planes. Then, the thickness of the coating material C is calculated based on the three-dimensional coordinates of the surface of the coating material and the multiple virtual planes. More specifically, as shown in step 140 described later, the thickness of each point on the surface of the coating material is calculated based on the displacement of each point from the nearest virtual plane. The entire thickness of the coating material C is obtained over the points on the entire surface of the coating material. Then, a coating material image is calculated, which is an image showing the surface of the coating material and shows the distribution of the thickness of the coating material in color or shade. The interval between each point is appropriately determined according to the resolution of the three-dimensional measuring device 10 or the display unit 30.
The display unit 30 is a two-dimensional monitor that displays the dressing material image created by the data processing unit 22. As the display unit 30, a tablet-type monitor is preferable in consideration of use in the field.

The coating material thickness measurement system 1 can calculate the overall thickness of the coating material by acquiring the application shape including the coating material C and reference markers M provided on the target surface W, thereby significantly reducing the workload of the worker. In particular, since multiple virtual planes are calculated based on at least three of the multiple reference markers M distributed in the application shape A, the target surface can be divided into areas corresponding to the multiple virtual planes, and even if there is distortion on the target surface, the worker does not accurately place the reference markers, or there is a measurement error in the three-dimensional measuring device, the effects of these can be minimized. Therefore, the thickness of each point on the coating material can be accurately measured.

Next, referring to the flowchart in FIG. 2, an embodiment of a method for measuring the thickness of a coating material applied to a target surface (hereinafter, referred to as a thickness measurement method) will be described. The coating material thickness measurement method includes a step of placing a reference marker (step 110), a step of acquiring an applied shape (step 120), a step of calculating a plurality of virtual planes (step 130), a step of calculating the thickness of the coating material (step 140), a step of displaying an image of the coating material (step 150), a step of determining whether finishing processing is necessary based on the coating material image (step 160), a step of performing finishing processing if it is determined that finishing processing is necessary (step 170), and a step of storing three-dimensional data of the coating material in association with the target surface if it is determined that finishing processing is not necessary (step 180).

A fiducial marker M is placed on the coating material (step 110). As shown in Fig. 3b, a pin N is inserted perpendicular to the target surface W, and four or more fiducial markers M are placed at positions a predetermined distance L away from the target surface W. The surfaces of these fiducial markers M are at a known distance from the target surface and are the same.
The installation positions of the reference markers M are not particularly limited, but it is preferable to distribute them over the entire target surface W. This allows multiple virtual planes to be created to cover the target surface W, making it possible to reduce errors in the calculation of the thickness of the coating material. It is also preferable to install the reference markers M at equal intervals in a lattice pattern. This allows the shape and size of each virtual plane to be averaged, making it possible to reduce errors in the calculation of the thickness of the coating material.
For example, in FIG. 1, six fiducial markers M are provided on the dressing C.

Next, an application shape is obtained (step 120), which includes the three-dimensional coordinates of the surface of the coating material and the three-dimensional coordinates of the fiducial markers M. For example, the application shape A in FIG. 3a includes the three-dimensional coordinates of the coating material C and the three-dimensional coordinates of the surface of the six fiducial markers M.
The construction shape A is, for example, a shape scanned by a three-dimensional measuring device 10 and recorded as point cloud data.

Calculate multiple virtual planes (step 130). In detail, select a reference marker M from the construction shape A, extract a reference point (reference three-dimensional coordinates) from the reference marker M, and calculate multiple virtual planes connecting at least three reference points. In other words, calculate multiple virtual planes by translating a part of the target surface W by a predetermined distance L in the vertical direction. For example, in FIG. 3c, four virtual planes V1, V2, V3, and V4 are calculated from six reference markers M.
The method of selecting the reference marker M from the construction shape A is to specify the construction shape based on its color or shape characteristics. Such recognition may be performed by the worker manually indicating the position of the reference marker on the screen, or may be automatically recognized by a computer processing unit.
The method of extracting the reference points from the reference markers M is not particularly limited, and is determined based on preset conditions on the basis of the three-dimensional coordinates of the reference markers M. For example, the barycentric coordinates of each reference marker M may be used.

The calculation of the virtual plane is performed by selecting at least three reference points from four or more reference points and calculating a plane surrounded by them. The selection of the reference points constituting the virtual plane may be performed by the operator manually indicating the position of the reference marker (reference point) on the screen, or may be automatically recognized by the data processing unit 22 based on a preset condition. For example, as shown in FIG. 3c, a method of dividing the largest plane formed based on six reference points so that the areas do not overlap and setting multiple virtual planes (virtual planes V1 to V4) can be exemplified. By making the areas of each virtual plane not overlap, each virtual plane can be made small, and the influence of distortion of the target surface and improper installation of the reference marker can be minimized. In addition, by dividing the largest plane formed based on all the reference points, the virtual plane can be set over a large area on the covering material, and the error in the thickness of the entire covering material can be reduced. The multiple virtual planes calculated here are independent of each other. In other words, if the target surface is an ideal plane, the multiple virtual planes are parallel and have the same distance from the target surface W, but in reality, there are many cases where they are slightly shifted.
It is preferable that each virtual plane is calculated based on the reference three-dimensional coordinates of three points. When calculating a virtual plane based on the reference three-dimensional coordinates of three points, a plane with three vertices can be uniquely obtained. However, one virtual plane may be calculated from the reference three-dimensional coordinates of four or more points. In that case, the three-dimensional coordinates of each reference point may not be on the plane due to the influence of unevenness of the target surface, measurement errors of the three-dimensional measuring device, inclination of the reference marker M with respect to the target surface W, etc. In that case, an average plane may be calculated for the three-dimensional coordinates of multiple reference points. In other words, a plane may be fitted. A known method may be used for this. For example, a least-squares plane may be obtained for the three-dimensional coordinates of multiple reference points by the least-squares method.
The number and size of the calculated virtual planes are not particularly limited, and can be set appropriately depending on the size of the target surface W, the final required measurement accuracy, the reference markers to be used, and the like.

Calculating the thickness of the coating material (step 140). More specifically, as shown in Fig. 2b, the method includes a step of selecting a point P on the surface of the coating material (step 141), a step of selecting a virtual plane closest to the point P (step 142), and a step of calculating the thickness of the point P on the surface of the coating material based on the selected virtual plane (step 143). Then, by performing calculations over all points on the surface of the coating material, the overall thickness of the surface of the coating material can be obtained.
The selection of the virtual plane closest to the point P on the surface of the covering material (step 142) is performed by selecting the virtual plane closest to the point P. For example, the distance between the point P and the center of gravity coordinates of each virtual plane may be obtained, and the virtual plane with the shortest distance may be selected. Alternatively, the point P and each virtual plane may be projected onto a predetermined two-dimensional plane (for example, an average plane obtained from all reference three-dimensional coordinates), and the inside/outside judgment between the projected point P and each virtual plane may be performed, and a virtual plane containing the point P may be selected. Alternatively, the X-axis and Y-axis are determined on a plane parallel to the target surface from the construction shape, and the selection is made based on a three-dimensional orthogonal coordinate system with the thickness direction as the Z-axis, and if there is a virtual plane containing a point with the same XY coordinates as the XY coordinates of the point P (if the point P is within the area of the nearest virtual plane), the virtual plane is selected. On the other hand, if there is no virtual plane containing a point with the same XY coordinates as the XY coordinates of the point P (if the point P is not within the area of the nearest virtual plane), the virtual plane containing the point closest to the point P on the projection plane projected in the Z direction is selected. In addition, the plane parallel to the target plane is not particularly limited, but is obtained by, for example, six reference three-dimensional coordinates. In Fig. 3c, the plane closest to point P1 is virtual plane V3, and the plane closest to point P2 is virtual plane V2.

Next, the thickness of the point P on the surface of the coating material is calculated based on the selected virtual plane (step 143). That is, assuming that the virtual plane V closest to the point P is parallel to the target surface W, the thickness of the point P is calculated based on the virtual plane V. In detail, if the point P is within the area of the closest virtual plane, the thickness of the point P is calculated from the displacement of the point P and the virtual plane in the Z direction. On the other hand, if the point P is not within the area of the closest virtual plane, the virtual plane is extended, and the thickness of the point P is calculated from the displacement of the point P and the extended part of the virtual plane in the Z direction. For example, as in the case of point P1 in FIG. 3c, if the point P1 is within the area of the closest virtual plane V3, the X'-axis and Y'-axis are set on the virtual plane V3, and the thickness T1 of the coating material point P1 is calculated as L-Z1 from the difference (Z1) between the Z'-coordinate of the point P1 and the Z'-coordinate of the virtual plane V3. In this way, when the X'-axis and the Y'-axis are determined based on the virtual plane V3, the thickness T1 of the point P1 is the thickness in the direction perpendicular to the virtual plane V3. Alternatively, the X'-axis and the Y'-axis may be determined based on the average plane of all the virtual planes or the average plane obtained from all the reference three-dimensional coordinates. This is preferable because the thicknesses at all points can be calculated in a common coordinate system. Each virtual plane may be translated in advance by L so as to be superimposed on the position of the target surface W. In this case, the thickness T1 of the coating material point P1 = Z1 = P1 - V3. Also, as in the case of point P2 in Figure 3c, when point P2 is not within the area of the nearest virtual plane V2, the X"-axis and the Y"-axis are determined parallel to the virtual plane V2, and the virtual plane V2 is extended to the X"Y" coordinate of point P2, and the thickness T2 of the coating material point P2 is L-Z2, which is the difference (Z2) between the Z" coordinate of point P2 and the Z" coordinate of the extended portion of the virtual plane V2. In FIG. 3c, the X-axis, Y-axis, and Z-axis set on a plane parallel to the target surface in step 142 are ideally parallel to the X'-axis, Y'-axis, and Z'-axis as well as the Z", Y", and Z"-axis; however, in reality, they are often not parallel.
This method makes it possible to calculate the thickness of the entire region of the coating material. The interval between each point is determined according to the resolution of the three-dimensional measuring device 10 or the display unit 30. This calculation may be performed by subtracting the point cloud coordinates of the surface of the coating material and the point cloud coordinates of the virtual plane, or the difference may be calculated by converting the point cloud into a mesh and calculating the difference between the surfaces.
The thickness of each point on the surface of the coating material is calculated based on the closest of multiple virtual planes whose distances from the target surface are known, so even if the target surface is uneven or there are measurement errors in the three-dimensional measuring device, the effects can be minimized.

A coating image is displayed (step 150). More specifically, a coating image showing the surface of the coating, in which the distribution of the coating thickness is shown by color or shading, is calculated and displayed.
Examples of images showing the surface of the coating material include a three-dimensional perspective image and a two-dimensional image in which the application shape is projected onto a specified plane (for example, a plane parallel to the target surface).

Whether or not finishing is required is determined based on the coating material image (step 160). In detail, based on the coating material image, the presence or absence of defective construction parts where the thickness of the coating material is out of a predetermined range is confirmed, and if there are defective construction parts, finishing is determined to be necessary, and if there are no defective construction parts, finishing is determined to be unnecessary. In addition, how thick or thin the part of the coating material is from a predetermined standard thickness is calculated, and whether the thickness is within the predetermined range is determined. When the coating material is used as a heat insulating material, an example of the construction standard is a range of -0 mm to +20 mm with respect to a standard thickness of 30 mm (a part thinner than the standard is defective, and a thicker part is allowed up to 20 mm). A more strict range of -0 mm to +5 mm can also be set. For example, in the coating material image of step 150, the defective construction parts may be displayed in color or shade (defective construction determination image). Also, for example, in the coating material image, the part may be identified by a leader line, and a numerical value indicating how far the part deviates from a predetermined value may be displayed. By identifying the defective construction parts in this way and clarifying the degree of defect, it is easy to perform the finishing process of step 170.
If it is determined that finishing processing is necessary, the process proceeds to step 170, and if it is determined that finishing processing is not necessary, the process proceeds to step 180.

If it is determined that finishing is necessary, finishing is performed (step 170). That is, if it is determined in step 160 that finishing is necessary, finishing is performed on the areas that require finishing so that the thickness of the coating material falls within a predetermined range. In more detail, for areas that are thicker than the predetermined range, the excess is cut off, and for areas that are thinner than the predetermined range, additional coating is sprayed or applied. After finishing is performed, the process returns to step 120, and the applied shape is obtained.
Thereafter, in step 160, steps 120 through 170 are repeated until no further finishing is required.

If it is determined that finishing is not necessary, the three-dimensional coordinates of the surface of the covering material and the thickness of the covering material, particularly the covering material image, are associated with the target surface and stored as a database (step 180). That is, if it is determined in step 160 that finishing is not necessary, the construction of the covering material is completed and the data is saved. For example, by storing the position information and identification information of the target surface, such as the east wall of Room 102, in association with the covering material image, the data can be used as database data managed for each target surface (wall). In addition, if 3D CAD data of a building exists, it is preferable to store the data in association with the 3D CAD data. In particular, more efficient process management and quality management are possible by storing the data in association with BIM (Building Information Modeling), which has been proposed in recent years. In particular, when there are many target surfaces such as buildings and apartment buildings, it is easy to manage. The three-dimensional shape before finishing may also be saved. This makes it possible to track the process of the work.
It is preferable to store these data as uneditable electronic files with security set by, for example, a password. In particular, it is preferable to store the data as uneditable electronic files with a time stamp to prove non-tampering and time-certified. By storing the data as uneditable electronic files, the objectivity of the data can be maintained.

In this way, the coating material thickness measurement method of this embodiment calculates multiple imaginary planes within the construction shape that are translated a predetermined distance in the direction perpendicular to the target surface based on four or more reference points, and calculates the thickness of point P on the surface of the coating material based on the imaginary plane that is closest to point P on the surface of the coating material, so that even if the target surface W is distorted, the reference marker is misaligned, or there is a measurement error in the three-dimensional measurement device, the influence of these factors can be minimized when measuring the thickness of the coating material. As a result, the coating material can also be finished accurately.
A coating application method using this thickness measurement method can provide coating materials of uniform quality, regardless of the skill level of the worker.

The method for measuring the thickness of the coating material described above is not limited to the above.
For example, in the step of installing the reference marker (step 110), the reference marker is installed on the covering material, but the reference marker may be installed near the covering material. For example, the reference marker may be installed on a pillar around the covering material. Where to install the reference marker can be appropriately determined according to the target surface. Also, the reference three-dimensional coordinates may be set on the surface of a structure located adjacent to or near the target surface and the distance from the target surface is known. Examples of the structure include structures such as pillars, sashes, thresholds, moldings, baseboards, beams, etc. located in the same room as the wall surface of the target surface, or structures having characteristic shapes such as boundaries between floors, ceilings, and walls, openings such as piping, doors, windows, and ventilation openings, and distribution boxes.
In the step of creating the coating material image (step 150), a coating material image in which thickness is indicated by color or shading is given, but a projection image or a three-dimensional image (perspective image) of the coating material without color or shading according to thickness may be used. Also, in step 150, instead of displaying only an image, a table relating position data on the target surface to thickness data of the coating material may be displayed.
The shape of the surface to be estimated may include a curved surface. The method of generating the curved surface is not particularly limited, and an approximate curved surface may be generated by a known method for four or more reference three-dimensional coordinates. For example, a Bezier surface, a B-spline surface, or a NURBS surface may be generated with four or more reference three-dimensional coordinates as control points. In this case, it is preferable to generate a curved surface passing through four or more reference three-dimensional coordinates. In addition, the degree of distortion and unevenness of the wall surface that may occur may be investigated in advance, and parameters at the time of generating the curved surface may be adjusted based on the degree of distortion and unevenness. When the shape of the surface to be estimated is a curved surface, the thickness of the point P can be obtained by calculating the difference between the three-dimensional coordinates of the surface of the coating material and the curved surface. A curved surface may be generated based on the three-dimensional coordinates of the surface of the coating material (point cloud data of the surface of the coating material), and the difference between the curved surfaces may be obtained.

REFERENCE SIGNS LIST 1 Thickness measurement system 10 Three-dimensional measurement device 20 Control unit 21 Memory unit 22 Data processing unit 30 Display unit A Installation shape C Coating material M Reference marker N Pin V1-V4 Virtual plane W Target surface

Claims (10)

A method for measuring the thickness of a covering material applied to a target surface of a building, comprising:
a step of, after the application of the coating material, inserting four or more pins having the same length and a reference marker at an upper end into the coating material so that the tips of the pins abut the target surface, thereby placing the reference marker on the coating material;
A step of acquiring a construction shape including three-dimensional coordinates of the surface of the coating material and three-dimensional coordinates of four or more reference three-dimensional coordinates on the reference markers, the distances of which from the target surface are known;
calculating an estimated object surface shape by estimating the object surface based on the reference three-dimensional coordinates of the four or more points;
calculating a thickness of the coating material based on the three-dimensional coordinates of the surface of the coating material and the estimated target surface shape ;
the estimated target surface shape is made up of a plurality of virtual planes calculated based on the four or more reference three-dimensional coordinates,
The thickness of the coating material is calculated by calculating the thickness of each point on the surface of the coating material based on the displacement of each point from the nearest imaginary plane.
How to measure coating thickness. Each of the virtual planes is calculated based on the reference three-dimensional coordinates of at least three points among the four or more reference three-dimensional coordinates.
The method for measuring the thickness of a coating material according to claim 1 . Calculating a thickness of each point on the surface of the coating material based on a virtual plane corresponding to each point among the plurality of virtual planes;
3. A method for measuring the thickness of a coating material according to claim 1 or 2 . Calculating the plurality of virtual planes so that their regions do not overlap;
The method for measuring the thickness of a coating material according to any one of claims 1 to 3 . displaying a coating image showing the distribution of the coating thickness in color or shade;
The method for measuring the thickness of a coating material according to any one of claims 1 to 4 . A step of determining whether or not there is a defective application portion where the thickness of the coating material is outside a predetermined range.
The method for measuring the thickness of a coating material according to any one of claims 1 to 5 . A step of determining whether or not there is a defective application portion where the thickness of the coating material is outside a predetermined range;
and displaying the defective application location on the coating material image.
The method for measuring the thickness of a coating material according to claim 5 . The covering material is a sprayed polyurethane foam insulation material.
The method for measuring the thickness of a coating material according to any one of claims 1 to 7 . A system for measuring the thickness of a covering material applied to a target surface of a building, comprising:
A three-dimensional measuring device,
a data processing unit,
the three-dimensional measuring device acquires a construction shape including three-dimensional coordinates of a surface of the coating material and four or more reference three-dimensional coordinates whose distances from the target surface are known;
the reference three-dimensional coordinates are three-dimensional coordinates on a reference marker provided at an upper end, the reference marker being set on the covering material by inserting four or more pins having the same length into the covering material such that tips of the pins abut the target surface;
the data processing unit calculates an estimated object surface shape by estimating the object surface based on the reference three-dimensional coordinates of the four or more points, the estimated object surface shape being composed of a plurality of virtual planes calculated based on the reference three-dimensional coordinates of the four or more points, and calculates a thickness of the coating material by calculating a thickness of each point on the surface of the coating material based on a displacement of each point from the nearest virtual plane based on the three-dimensional coordinates of the surface of the coating material and the estimated object surface shape;
Coating thickness measurement system. A method for applying a covering material to a target surface of a building, comprising:
applying a coating to the target surface;
a step of inserting four or more pins having the same length and each having a reference marker at its upper end into the covering material such that the tips of the pins abut the target surface, thereby placing the reference marker on the covering material;
acquiring three-dimensional coordinates of the surface of the dressing and three-dimensional coordinates of four or more reference points on the fiducial markers, the distances of which from the target surface are known;
calculating an estimated object surface shape by estimating the object surface based on the reference three-dimensional coordinates of the four or more points;
calculating a thickness of the coating material based on three-dimensional coordinates of a surface of the coating material and the estimated target surface shape;
A step of determining whether or not there is a defective application portion where the thickness of the coating material is outside a predetermined range,
the estimated target surface shape is made up of a plurality of virtual planes calculated based on the four or more reference three-dimensional coordinates,
The thickness of the coating material is calculated by calculating the thickness of each point on the surface of the coating material based on the displacement of each point from the nearest imaginary plane.
How to apply the covering material.

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