Measuring method

Abstract

To provide a method for efficiently measuring a roughening state.SOLUTION: A measuring method includes: measurement processing that uses a measuring instrument using a LIDAR technique to measure a surface part of a concrete structure; and evaluation processing that uses point cloud data obtained by the measuring instrument to evaluate a roughening state of the surface part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a measurement method. [Background technology]

[0002] Patent Document 1 discloses a method for measuring the state of roughening of a concrete surface using a sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-164060 Summary of the Invention [Problem to be solved by the invention]

[0004] With the above configuration, the measurement range is limited to the area where the friction resistor placed on the concrete surface comes into contact, making it difficult to measure a wide area at once or to grasp the distribution of roughening in a short period of time.

[0005] In view of the above, an object of the present invention is to provide a method for efficiently measuring the state of roughening. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, one aspect of the present invention provides a measurement method including a measurement process for measuring the surface portion of a concrete structure using a measurement device that employs LIDAR technology, and an evaluation process for evaluating the state of roughening of the surface portion using point cloud data obtained by the measurement device.

[0007] Other problems and solutions disclosed in the present application will be made clear in the detailed description and drawings. [Effects of the Invention]

[0008] According to the present invention, a method for efficiently measuring the state of roughening is provided. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a measurement device according to an embodiment. [Figure 2] FIG. 2 is an explanatory diagram of the functional configuration of a measurement device according to an embodiment. [Figure 3] FIG. 1 is a conceptual diagram illustrating a process of forming point cloud data. [Figure 4] This is the definition of the roughening area ratio. [Figure 5] 1 is a table showing measurement parameters in an example. [Figure 6] 1A is a diagram showing the location of chipping in a concrete structure that was the subject of measurement in an example, and FIG. 1B is a photograph showing the state of chipping. [Figure 7] FIG. 10 is a diagram showing point cloud data obtained as a result of measurement in the example. [Figure 8] 10 is a graph showing the distribution of the depth from the surface in the Z direction for each measurement in the example. [Figure 9] 1 is a table comparing the roughening area ratios obtained in the examples between the respective measurements. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, identical or similar components may be designated by common reference numerals, and redundant description may be omitted.

[0011] First Embodiment (overview) Fig. 1 is an explanatory diagram of the overall configuration of a measurement device 1 in the first embodiment. Fig. 2 shows functional blocks relating to each functional unit in the measurement device 1.

[0012] The measuring device 1 is a device that performs measurements using LIDAR (Light Detection and Ranging) technology, and is capable of measuring the distance to a surface portion 90 that forms the surface layer of a concrete structure. In the surface portion 90, the hardened concrete surface has been previously chipped or roughened using a chipping or hammer, resulting in the formation of irregularities. As a result, the surface portion 90 has a smooth surface portion 91 and a recessed portion 92 that is recessed from the surface portion 91.

[0013] The measuring device 1 emits measurement light, detects the light reflected by the surface of the surface portion 90, and measures the time from emitting the measurement light to receiving the reflected light, thereby measuring the distance to the surface portion 90 by a time of flight (TOF) method. The measuring device 1 has an irradiation unit 10, a light receiving unit 20, a control unit 30, and a memory unit 50.

[0014] The irradiation unit 10 irradiates measurement light toward the surface portion 90. The irradiation unit 10 irradiates the measurement light at a predetermined angle of view. The irradiation unit 10 has a light source 12 and a light projection optical system 14. The light source 12 emits light. The light source 12 is configured, for example, by a vertical cavity surface emitting laser (VCSEL). The light projection optical system 14 is an optical system that irradiates the light emitted from the light source 12 onto the surface portion 90.

[0015] In the following description, the direction along the optical axis of the light projecting optical system 14 (shown by a dashed line in FIG. 1) is referred to as the Z direction. Note that the surface portion 90 to be measured by the measurement device 1 is spaced apart from the measurement device 1 in the Z direction. The direction perpendicular to the Z direction, in which the light projecting optical system 14 and the light receiving optical system 24 are aligned, is referred to as the Y direction. The direction perpendicular to the Z and Y directions is referred to as the X direction.

[0016] The light projection optical system 14 is an optical system for irradiating the light emitted from the light source 12 toward the surface portion 90. The light source 12 is disposed within the focal plane of the light projection optical system 14. The light projection optical system 14 irradiates the light emitted from the light emitting element of the light source 12 as collimated light onto the surface portion 90. Each of the light projection optical systems 14 is made up of a lens group made up of a plurality of lenses (for example, 5 to 7 lenses) (in FIG. 1, the lens group of the light projection optical system 14 is shown simply).

[0017] The light receiving section 20 receives the light reflected from the surface portion 90. The light receiving section 20 receives the light reflected from the surface portion 90. The light receiving section 20 has a light receiving sensor 22 and a light receiving optical system 24.

[0018] The light-receiving optical system 24 is an optical system for causing the light-receiving sensor 22 to receive the light reflected from the surface portion 90. The light-receiving sensor 22 is disposed within the focal plane of the light-receiving optical system 24. The light-receiving optical system 24 focuses the light reflected from the surface portion 90 onto the light-receiving element of the light-receiving sensor 22. Like the light-projecting optical system 14, the light-receiving optical system 24 is also composed of a lens group made up of multiple lenses (for example, 5 to 7 lenses) (in FIG. 1, the lens group of the light-receiving optical system 24 is shown simply).

[0019] The measuring device 1 may further include a scanner. The scanner has a function of scanning the laser light by changing the angle at which the laser light is irradiated. Various scanning methods, such as photonic crystals and liquid crystals, may be adopted. For example, the scanner may include a rotating or moving mirror, such as a galvanometer scanner or an MEMS mirror, and the laser light may be reflected by this mirror to scan the laser light. The mirror may be one or more flat mirrors or may be formed in a polyhedral shape. Alternatively, the scanner may include a driving device such as a motor, and the laser light may be scanned by moving the projection optical system 14 in the X and Y directions.

[0020] Furthermore, the measuring device 1 may be a fixed device mounted on a tripod or a table, or may be a handheld device. During measurement, it is desirable that the measuring device 1 and the surface portion 90 are as directly opposed as possible. In particular, it is preferable to install the measuring device 1 so that the angle of the measurement light with respect to the normal to the surface portion 91 is within 20 degrees.

[0021] The control unit 30 controls the measurement device 1 (FIG. 2). The control unit 30 controls the irradiation of light from the irradiation unit 10. The control unit 30 also measures the distance to the surface portion 90, for example, by a TOF (Time of Flight) method, based on the output result of the light receiving unit 20. The control unit 30 has a calculation unit and a storage device (not shown). The calculation unit is, for example, a calculation processing device such as a CPU or GPU. A part of the calculation unit may be configured with an analog calculation circuit.

[0022] The distance measurement method executed by the control unit 30 may be a continuous wave (CW) modulation method or a frequency modulated continuous wave (FMCW) method.

[0023] The storage unit 50 is configured with a main storage device and an auxiliary storage device, and is a device for storing programs and data. The program stored in the storage unit 50 is executed by the arithmetic device, and various processes for measuring the distance to the surface portion 90 are performed.

[0024] The storage unit 50 can store data acquired by the control unit 30. For example, data obtained when the light receiving unit 20 receives reflected light is saved in the storage unit 50 and used for subsequent analysis processing, etc.

[0025] The control unit 30 has a setting unit 32, a timing control unit 34, and a distance measurement unit 36. The setting unit 32 performs various settings. The timing control unit 34 controls the processing timing of each unit. For example, the timing control unit 34 controls the timing of emitting light from the light source 12. The distance measurement unit 36 ​​measures the distance to the surface portion 90. The distance measurement unit 36 ​​has a signal processing unit 362, a time detection unit 364, and a distance calculation unit 366. The signal processing unit 362 processes the output signal of the light receiving sensor 22. The time detection unit 364 detects the time of flight of light (the time from when light is emitted until the reflected light arrives). The distance calculation unit 366 calculates the distance to the surface portion 90.

[0026] Furthermore, the control unit 30 is capable of calculating the distance to the surface portion 90 based on the output data of the distance measuring unit 36, and creating data (referred to as point cloud data) that indicates the three-dimensional shape of the surface portion 90.

[0027] Specifically, as shown in the conceptual diagram of FIG. 3, the measuring device 1 controlled by the control unit 30 sets multiple measurement points on the object to be measured, such as a surface portion 90, irradiates each point with a laser, acquires data on the X, Y, and Z coordinates of the multiple measurement points, and compiles them as point cloud data.

[0028] Note that image data and point cloud data representing surface portion 90 may be generated using an external control device or the like different from measuring device 1, rather than control unit 30. In that case, output data from distance measuring unit 36 ​​is output to the outside of measuring device 1, and an external device having a configuration similar to control unit 30 performs the same processing as above to create and output point cloud data.

[0029] The control unit 30 also evaluates the state of roughening according to Equation 1 shown in Fig. 4. Specifically, as shown in Equation 1, the state of roughening is evaluated based on the ratio (roughening area ratio) between the area of ​​the portion of the surface portion 90 measured by the measuring device 1 and the area of ​​the portion of the measured portion that has a depth in the Z direction from the surface portion 91 that is greater than a threshold value. The threshold value is set appropriately depending on the design conditions, but is preferably set to 2 mm (millimeters).

[0030] (Example) As an example, the condition of a surface portion 90 of a concrete structure was actually measured using the measuring device 1. As shown in FIG. 5, the measurement accuracy (error) and measurement distance were changed and measurements were taken multiple times. The measurement distance is the distance from the surface portion 91 to the measuring device 1. A Leica ATS600 (simply referred to as "LT") was used as the measuring device 1. In this case, the measurement distance is preferably in the range of 1.5 m to 60 m.

[0031] The surface portion 90 to be measured was a square with sides of 500 mm as shown in FIG. 6(a), and recesses 92 were formed at intervals of 100 mm by chipping (FIG. 6(b)).

[0032] The point cloud data obtained as a result of the measurement is shown in Figure 7. Figure 7 shows a cross section (Y, Z directions) of the surface portion 90, from which the shape and depth of the recess 92 can be read. It is desirable that the measurement distance be in the range of 1.5 m or more and 60 m or less, but it can be seen that the shape of the recess 92 can be accurately measured even when the measurement distance is set to 1300 mm. Therefore, it can be seen that measurement is possible even when the measurement distance is 1.3 m or more and 60 m or less.

[0033] The Z-direction depth distribution and roughening area ratio of the point cloud data obtained by measurement are shown in Figures 8 and 9. In Figure 9, the threshold for calculating the roughening area ratio is set to 2 mm.

[0034] As shown in FIG. 8, it can be seen that the shape of the recess 92 is captured even when the measurement is taken from a distance of 1300 mm.

[0035] <Effects> The above-described embodiments and modifications provide the following aspects.

[0036] (Aspect 1) In the above embodiment, a measurement method is shown that includes a measurement process that measures a surface portion 90 of a concrete structure using a measurement device 1 that employs LIDAR technology, and an evaluation process that evaluates the state of roughening of the surface portion 90 using point cloud data obtained by the measurement device 1.

[0037] The above configuration allows for the measurement of minute irregularities with high accuracy and enables rapid measurement. Furthermore, accurate measurements are not affected by the dryness or wetness of the concrete surface, temperature, or brightness, so measurement work can be carried out outdoors regardless of the time of day or weather. For example, even in the rain in the evening, the condition of the roughening can be checked on-site using a terminal, and point cloud data can be processed in a safe location. This allows for accurate and reliable construction of joint surfaces. In this way, the above configuration allows for efficient measurement of the condition of the roughening.

[0038] (Embodiment 2) In embodiment 1, the measurement device 1 is placed within a range of 1.3 m to 60 m from the surface portion 91 of the face portion 90 to perform measurements.

[0039] By being placed in the above position, the measuring device 1 is able to perform highly accurate measurements.

[0040] (Embodiment 3) In embodiment 1 or 2, the state of roughening is evaluated based on the ratio between the area of ​​the portion of surface portion 90 measured by measuring device 1 and the area of ​​the portion of the measured portion that is deeper than 2 mm from the surface of the surface portion.

[0041] By evaluating the state of roughening using the above method, it is possible to accurately evaluate whether roughening has been performed appropriately. [Explanation of symbols]

[0042] 1. Measuring equipment 10 Irradiation unit 12 light source 14 Light projection optical system 20 Light receiving section 22 Light receiving sensor 24 Light receiving optical system 90 face part

Claims

1. A measurement process that measures the surface of a concrete structure using a measurement device that uses LIDAR technology; an evaluation process for evaluating the state of roughening of the surface portion using the point cloud data obtained by the measurement device; Includes measurement methods.

2. In the measurement process, The measurement device is disposed within a range of 1.3 m to 60 m from the surface of the face portion. The evaluation method according to claim 1 .

3. In the evaluation process, evaluating the condition based on a ratio between an area of ​​the portion of the surface measured by the measuring device and an area of ​​a portion of the measured portion that is deeper than 2 mm from the surface of the surface; The evaluation method according to claim 1 or 2.

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