System and method for bar arrangement inspection of structure including rebar

Abstract

To improve the efficiency of bar arrangement inspection.SOLUTION: A rebar arrangement inspection system includes a three dimensional scanner that acquires three dimensional information of a structure including rebars, a processing device that acquires preliminary data on arrangement of the rebars and design information of the rebars, sets a measurement operation of the three dimensional scanner based on the preliminary data, and collates the three dimensional information acquired by the three dimensional scanner by the measurement operation based on the setting with the design information, and an output device that outputs a result of a rebar arrangement inspection of the rebars based on a result of the collation.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] SUMMARY The present disclosure relates to systems and methods for inspecting rebar placement (i.e., reinforcement) in structures that include rebar. [Background technology]

[0002] Reinforcement inspection in construction work is an important inspection to verify the strength, durability, and other performance of a building. During the inspection process, it is required to check and record each time that the reinforcing bars are the components specified in the design drawings, and that they are arranged and numbered according to the design drawings. Various techniques used for reinforcing bar inspection are disclosed in Patent Documents 1 to 3, for example.

[0003] Patent Document 1 discloses a reinforcement inspection system that uses a 3D laser scanner. This reinforcement inspection system generates a point cloud composite image by combining 3D point cloud data acquired by the 3D laser scanner with image data of the inspection area captured by a camera, and compares the point cloud composite image with design data to generate 3D reinforcement condition inspection result data.

[0004] Patent document 2 discloses a method for generating information on the diameter, spacing, and number of rebars based on 3D point cloud data obtained by measuring a specified area from an image of a rebar with a strip-shaped inspection sheet attached along its longitudinal direction using LiDAR.

[0005] Patent Document 3 discloses a method of performing three-dimensional measurements from multiple positions using a three-dimensional laser scanner and judging the state of reinforcement based on shape data obtained by integrating the results of these three-dimensional measurements. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-52435 [Patent Document 2] Japanese Patent Publication No. 2023-166058 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-014693 Summary of the Invention [Problem to be solved by the invention]

[0007] Three-dimensional measurements using a three-dimensional scanner have the drawback of requiring long measurement times and complicated operations for full-point or repeated measurements.

[0008] The present disclosure provides a system and method that improves the measurement efficiency of 3D measurements using a 3D scanner in reinforcement inspection, and enables measurement of reinforcement status in a shorter measurement time. [Means for solving the problem]

[0009] A reinforcement bar inspection system according to one embodiment of the present disclosure includes a 3D scanner that acquires 3D information of a structure including reinforcing bars, a processing device that acquires preliminary data regarding the arrangement of the reinforcing bars and design information of the reinforcing bars, configures the measurement operation of the 3D scanner based on the preliminary data, and compares the 3D information acquired by the 3D scanner through the measurement operation based on the settings with the design information, and an output device that outputs the results of the reinforcement bar inspection based on the results of the comparison.

[0010] A comprehensive or specific aspect of the present disclosure may be realized by a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium such as a computer-readable recording disk, or by any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium. The computer-readable recording medium may include a volatile recording medium or a non-volatile recording medium such as a CD-ROM (Compact Disc - Read Only Memory). An apparatus may be composed of one or more devices. When an apparatus is composed of two or more devices, the two or more devices may be located in a single device or may be located separately in two or more separate devices. In this specification and claims, the term "apparatus" may refer not only to a single device but also to a system consisting of multiple devices. [Effects of the Invention]

[0011] According to the embodiments of the present disclosure, the measurement efficiency of three-dimensional measurement is improved, and reinforcement inspection can be performed in a shorter time. [Brief explanation of the drawings]

[0012] [Figure 1A] FIG. 1A is a block diagram showing an example of a schematic configuration of a bar arrangement inspection system according to a first embodiment. [Figure 1B] FIG. 1B is a block diagram showing another example of the schematic configuration of the bar arrangement inspection system according to the first embodiment. [Figure 2] FIG. 2 is a block diagram illustrating an example of the configuration of a LiDAR sensor. [Figure 3] FIG. 3 is a flowchart showing an example of the operation of the reinforcement bar arrangement inspection system. [Figure 4] FIG. 4 is a flowchart showing an example of a part of the measurement operation of the bar arrangement inspection system. [Figure 5] FIG. 5 is a flowchart showing an example of a part of the measurement operation of the bar arrangement inspection system. [Figure 6]FIG. 6 is a flowchart showing an example of a part of the measurement operation of the bar arrangement inspection system. [Figure 7] FIG. 7 is a schematic diagram showing an example of a method for calculating the probability of the presence of reinforcing bars. [Figure 8] FIG. 8 is a flowchart showing an example of a part of the measurement operation of the bar arrangement inspection system. [Figure 9] FIG. 9 is a block diagram showing a schematic configuration of a bar arrangement inspection system according to the second embodiment. [Figure 10] FIG. 10 is a flowchart showing an example of the operation of the bar arrangement inspection system. [Figure 11] FIG. 11 is a flowchart showing an example of a part of the measurement operation of the bar arrangement inspection system. [Figure 12] FIG. 12 is a diagram schematically illustrating an example of a structure to be inspected and an installation range of a 3D scanner. [Figure 13] FIG. 13 is a flowchart showing an example of a part of the measurement operation of the bar arrangement inspection system. [Figure 14] FIG. 14 is a flowchart showing an example of a part of the measurement operation of the bar arrangement inspection system. [Figure 15] FIG. 15 is a block diagram showing an example of a schematic configuration of a bar arrangement inspection system according to the third embodiment. [Figure 16A] FIG. 16A is a block diagram showing another example of the schematic configuration of the bar arrangement inspection system according to the third embodiment. [Figure 16B] FIG. 16B is a block diagram showing yet another example of the schematic configuration of the bar arrangement inspection system according to the third embodiment. [Figure 17] FIG. 17 is a flowchart showing an example of the operation of the bar arrangement inspection system. [Figure 18] FIG. 18 is a flowchart showing an example of a part of the measurement operation of the bar arrangement inspection system. [Figure 19] FIG. 19 is a flowchart showing an example of a part of the measurement operation of the bar arrangement inspection system. [Figure 20] FIG. 20 is a flowchart showing an example of a part of the measurement operation of the bar arrangement inspection system. [Figure 21] FIG. 21 is a flowchart showing an example of a part of the measurement operation of the bar arrangement inspection system. [Figure 22] FIG. 22 is a flowchart showing an example of a part of the measurement operation of the bar arrangement inspection system. DETAILED DESCRIPTION OF THE INVENTION

[0013] Exemplary embodiments of the present disclosure will be described in detail below. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, components, component arrangements and connection forms, steps, and step orders shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not recited in the independent claims that represent the highest concepts will be described as optional components. Furthermore, each figure is a schematic diagram and is not necessarily an exact illustration. Furthermore, in each figure, the same or similar components are denoted by the same reference numerals, and redundant explanations may be omitted or simplified.

[0014] In this disclosure, all or part of a circuit, unit, device, component, or part, or all or part of a functional block in a block diagram, may be implemented by one or more electronic circuits, including, for example, a semiconductor device, a semiconductor integrated circuit (IC), or an LSI (large scale integration). An LSI or IC may be integrated into a single chip or may be configured by combining multiple chips. For example, multiple functional blocks may be integrated into a single chip. While the terms LSI and IC are used here, the term may be changed depending on the degree of integration, and electronic circuits called system LSI, VLSI (very large scale integration), or ULSI (ultra large scale integration) may also be used. Field programmable gate arrays (FPGAs), which are programmable after LSI fabrication, or reconfigurable logic devices (RLDs), which can reconfigure connections within an LSI or set up circuit partitions within an LSI, can also be used for the same purpose.

[0015] Furthermore, all or part of the functions or operations of a circuit, unit, device, component, or section can be implemented by software processing. In this case, the software is recorded on one or more non-transitory recording media such as ROMs, optical disks, hard disk drives, etc., and when the software is executed by a processor, the functions specified in the software are performed by the processor and peripheral devices. A system or device may include one or more non-transitory recording media on which software is recorded, a processor, and necessary hardware devices, such as interfaces.

[0016] [Embodiment 1] A reinforcement inspection system according to a first exemplary embodiment of the present disclosure will be described. The reinforcement inspection system of this embodiment acquires three-dimensional information of a structure containing rebars, compares the rebar arrangement shown in the design drawings with the rebar arrangement of the rebars laid during the construction process, and outputs the inspection results. The three-dimensional information includes three-dimensional coordinate values ​​of multiple measurement points on the structure and is also referred to as "three-dimensional position information." The reinforcement inspection system can be used, for example, in the construction process of buildings such as houses or buildings, or structures such as bridges or roads. Alternatively, the reinforcement inspection system can also be used in the construction process of buildings such as monuments or other structures that use rebars.

[0017] <Configuration> 1A is a block diagram showing a schematic configuration of a bar arrangement inspection system 100 according to a first embodiment. The bar arrangement inspection system 100 includes a three-dimensional (3D) scanner 110, a processing device 120, a storage device 130, an input device 140, and an output device 150. The 3D scanner 110 includes a LiDAR sensor 111, an optical deflector 112, a control circuit 113, and a storage device 114.

[0018] The 3D scanner 110 is a measurement device that acquires three-dimensional information of a structure to be measured. The 3D scanner 110 may be configured to perform ranging by changing the direction of emitted light along two orthogonal axes according to a scan plan stored in the storage device 114, and generate three-dimensional point cloud data. The 3D scanner 110 may be configured to perform measurements using, for example, ToF (Time of Flight) or FMCW (Frequency Modulated Continuous Wave) LiDAR (Light Detecting and Ranging) technology.

[0019] The LiDAR sensor 111 may include a laser light source, a photodetector that detects light reflected from an object, and a processor that calculates the distance to the object based on the signal output from the photodetector.

[0020] The optical deflector 112 may be a device including, for example, a polygon mirror, a galvanometer, a micro-electromechanical system (MEMS), or other elements. The optical deflector 112 may also be called a "scanner." The optical deflector 112 is configured to two-dimensionally change the direction of the light beam emitted from the LiDAR sensor 111. For example, the optical deflector 112 can two-dimensionally change the emission direction of the light beam by rotating a mirror around two orthogonal axes. The optical deflector 112 may include multiple electric motors that rotate the mirror around the two axes. The optical deflector 112 may also be configured to change the emission direction of the light beam by using a phased array instead of a mirror.

[0021] The control circuit 113 controls the LiDAR sensor 111 and the optical deflector 112. The control circuit 113 may include one or more processors, such as a CPU. The control circuit 113 controls the LiDAR sensor 111 and the optical deflector 112 to change the direction of light emitted by the LiDAR sensor 111, thereby adjusting the irradiation direction. The LiDAR sensor 111 receives reflected light from an object using a photodetector and measures the distance to the object based on a signal output from the photodetector. For example, the LiDAR sensor 111 may perform ranging using ToF technology, which calculates the distance to the object based on the difference between the time a light beam is emitted and the time the reflected light is detected. Alternatively, the LiDAR sensor 111 may perform ranging using FMCW technology, which emits light whose frequency varies over time, generates interference light between the emitted light and the reflected light, and calculates the distance based on the frequency of the interference light.

[0022] FIG. 2 is a block diagram showing an example configuration of a LiDAR sensor 111. In this example, the LiDAR sensor 111 is configured to perform distance measurement using FMCW technology. The LiDAR sensor 111 shown in FIG. 2 includes a light source 119, an interference optical system 116, a photodetector 117, and a processor 118. The light source 119 emits laser light whose frequency periodically varies in response to a control signal input from the control circuit 113. The frequency of the laser light emitted from the light source 119 is modulated at a constant time period, such as a triangular wave or a sawtooth wave. The frequency modulation period may be, for example, 1 μs to 10 ms. The frequency modulation amplitude may be, for example, 100 MHz to 1 THz. The wavelength of the laser light may be in the near-infrared wavelength range, for example, 700 nm to 2000 nm. The wavelength of the laser light may also be in the visible light or ultraviolet wavelength range. The interference optical system 116 separates the laser light emitted from the light source 119 into output light and reference light, generates interference light between the light reflected from the moving object and the reference light, and inputs the interference light to the photodetector 117. The photodetector 117 outputs an electrical signal according to the intensity of the received light. The processor 118 calculates the distance from the LiDAR sensor 111 to the object based on the signal output from the photodetector 117. In addition to calculating the distance, the processor 118 may be configured to generate three-dimensional point cloud data including information on the three-dimensional coordinates of each reflection point.

[0023] 1A again. The storage device 114 is a device including any storage medium, such as a semiconductor storage medium or a magnetic storage medium. The storage device 114 stores various data referenced by the control circuit 113 when performing processing. The storage device 114 may also store computer programs executed by the processor of the control circuit 113.

[0024] The processing device 120 is a device including one or more processors such as a CPU. The processing device 120 transmits control signals to the 3D scanner 110 and controls the measurement operation, i.e., the scanning operation, performed by the 3D scanner 110. The processing device 120 sets a plan for the scanning operation and transmits the plan for the scanning operation to the 3D scanner 110. The processing device 120 also acquires information such as the distance measurement results, the light irradiation direction, and the measurement time from the 3D scanner 110, and performs processing based on this information.

[0025] The storage device 130 is a device that includes any storage medium, such as a semiconductor storage medium or a magnetic storage medium. The storage device 130 stores data such as functions and processing parameters that are referenced when the processing device 120 performs processing. The storage device 130 may also store computer programs that are executed by the processor of the processing device 120.

[0026] The input device 140 is a device or interface that inputs information to the processing device 120. The input device 140 may be configured to accept, for example, data input from another device such as an external sensor, or an input operation by a user.

[0027] The output device 150 is a device or interface that outputs the results of the reinforcement inspection to an external device. The output device 150 may be configured to output information to an external device, such as a display or an audio output device. This allows the reinforcement inspection system 100 to present the inspection results to a user. The output device 150 may be configured to output the results of the reinforcement inspection as an electronic file or by printing them on paper or the like via a printer.

[0028] The input device 140 and the output device 150 may be communication interfaces configured to communicate with external devices over a communication network.

[0029] The 3D scanner 110 may be configured to perform 3D measurements of buildings and other structures containing reinforcing bars while fixed, for example, on a tripod. Alternatively, a user may perform measurements while holding the 3D scanner 110. The 3D scanner 110 may be mounted on a mobile object that can move automatically or manually, such as a drone or an AGV (Automated Guided Vehicle). The reinforcement inspection system 100 may further include an actuator that changes the position and / or attitude of the 3D scanner 110. Such an actuator may include one or more electric motors and be configured to change the attitude of the 3D scanner 110 by translating and / or rotating the 3D scanner 110 under control of the processing device 120. The 3D scanner 110 may be configured to constantly align the measurement axis with the horizontal axis and the vertical axis through attitude control operation.

[0030] FIG. 1B is a block diagram showing a schematic configuration of a reinforcement bar arrangement inspection system 100 according to a modified example of this embodiment. The configuration shown in FIG. 1B is the same as the configuration shown in FIG. 1A except that the 3D scanner 110 includes an attitude sensor 115 used for attitude control. The attitude sensor 115 may be an inertial measurement unit (IMU) including, for example, an acceleration sensor and / or an angular velocity sensor such as a gyroscope. The attitude sensor 115 senses the attitude of the 3D scanner 110 and transmits tilt information of the 3D scanner 110 to the processing device 120. The processing device 120 may control the attitude of the 3D scanner 110 by driving an actuator based on the acquired tilt information. The processing device 120 may correct the irradiation direction and irradiation range based on the acquired tilt information to eliminate the influence of the tilt. The processing device 120 may create a scan plan based on the corrected irradiation direction and irradiation range and transmit the information to the control circuit 113 and storage device 114 of the 3D scanner 110.

[0031] The processing device 120, the storage device 130, the input device 140, and the output device 150 may be components of a single computer. For example, a personal computer (PC), laptop computer, tablet terminal, or smartphone that is connected to the 3D scanner 110 via a wired or wireless connection may include the processing device 120, the storage device 130, the input device 140, and the output device 150. Alternatively, a server computer connected to the 3D scanner via a communication network may include components such as the processing device 120 and the storage device 130. In this way, the processing device 120, the storage device 130, the input device 140, and the output device 150 may be installed in a location remote from the 3D scanner 110.

[0032] <Operation> Fig. 3 is a flowchart showing an outline of the operation of the reinforcement bar arrangement inspection system 100 in this embodiment. The operation of the reinforcement bar arrangement inspection system 100 will be described with reference to Fig. 3. When a start signal is input via the input device 140, the reinforcement bar arrangement inspection system 100 starts operation. The start signal can be input, for example, when the user performs an operation to instruct the start of measurement. The operation of each step shown in Fig. 3 will be described below.

[0033] (Step S1100) The processing device 120 acquires design information. The design information may be an electronic file recording information about the design of a building, including rebars. The design information may include, for example, a blueprint of the building, the type of each structure included in the building (columns, beams, slabs, walls, etc.), the arrangement of rebars, the width of each rebar, and the spacing between rebars. The processing device 120 acquires the electronic file from a storage medium, such as the storage device 130. Alternatively, the processing device 120 may acquire the design information from an external device via the input device 140. For example, the processing device 120 may acquire an electronic file containing the design information from a data storage location, such as a specific website, via a network. In this way, the processing device 120 may acquire the electronic file of design information from a device or system other than the reinforcement inspection system 100 via wired or wireless communication.

[0034] (Step S1200) The processing device 120 creates a measurement plan for the 3D point cloud data to be measured by the 3D scanner 110 based on the acquired design information. For example, the processing device 120 divides the measurement area into multiple areas so that measurements can be performed for each floor of a building, each room, or each structure such as a column, and determines the order of measurements for these areas. Alternatively, the processing device 120 may divide an area containing rebar in a design drawing for a floor where a reinforcement inspection is to be performed into multiple areas and determine the order of measurements for these areas. The order of measurements for multiple areas may be determined based on input from a user. For example, the user may input the order of work for each area in the building via the input device 140. As an example of dividing the areas, the areas may be divided according to the groups of structures such as columns, beams, slabs, and walls indicated in the design information. A detailed example of the operation of step S1200 will be described later.

[0035] (Step S1300) The processing device 120 determines whether measurement of all areas included in the measurement plan set in step S1200 has been completed or whether an end signal instructing the end of measurement has been input via the input device 140. When measurement of all planned areas has been completed or when an end signal has been input, the reinforcement bar arrangement inspection system 100 ends its operation. When measurement of all planned areas has been completed and an end signal has not been input, the process proceeds to step S1400.

[0036] (Step S1400) The processing device 120 selects an incomplete measurement region from the multiple measurement regions set in step S1200 and instructs the 3D scanner 110 to perform a primary scan to roughly scan that region. Following the instruction from the processing device 120, the 3D scanner 110 performs a primary scan to acquire preliminary data containing 3D point cloud data including the 3D position information of multiple reflection points. The 3D position information included in this preliminary data is sometimes referred to as "preliminary 3D information." The processing device 120 sets a motion plan for the primary scan based on the design information for the selected measurement region and transmits the information to the control circuit 113 and the storage device 114 of the 3D scanner 110. The motion plan is a plan regarding the direction and order in which light is irradiated. Details of the setting of the motion plan for the primary scan and the scanning operation will be described later.

[0037] (Step S1500) The processing device 120 sets an operation plan for a detailed scan to acquire information about the rebars in the measurement area based on the 3D position information obtained by the primary scan in step S1400. The operation plan can be generated as data that specifies the direction and order of light irradiation. Details of setting the operation plan for the detailed scan will be described later.

[0038] (Step S1600) The processing device 120 causes the 3D scanner 110 to perform a detailed scan. The 3D scanner 110 performs detailed 3D measurements of the structure, including the rebars, in the area in accordance with the scan plan set in step S1500. As a result, 3D point cloud data including 3D position information of multiple reflection points is acquired.

[0039] (Step S1700) The processing device 120 identifies the position and shape of the rebars based on the three-dimensional position information acquired in step S1600. Based on the identified position and shape of each rebar, the processing device 120 calculates physical quantities such as the inclination, curvature, thickness, spacing between rebars, and / or the average number of rebars per reference area of ​​each rebar, and sets these as measurement values. The processing device 120 compares the measurement values ​​with design values. Details of the operation of step S1700 will be described later.

[0040] (Step S1800) The processing device 120 determines whether there is a discrepancy between the measured value indicating the reinforcement state calculated in step S1700 and the design value indicated by the design information. Whether there is a discrepancy can be determined based on whether the difference between the measured value and the design value is greater than a threshold. If there is no discrepancy between the measured value and the design value, the process proceeds to step S1900. If there is a discrepancy between the measured value and the design value, the process proceeds to step S2100.

[0041] (Step S1900) The output device 150 generates and outputs output data including measurement values ​​such as the position, shape, inclination, bending, thickness, spacing, and / or average number of rebars. The output may be, for example, presentation of information on the rebar arrangement inspection results for the measurement area on a display or an audio output device. Alternatively, the output may be transfer and recording of the inspection results to a storage medium or other system, or printing on paper media, etc.

[0042] (Step S2100) The processing device 120 identifies the portion where the results of the 3D measurement taken in step S1600 differ from the design information of the region. The processing device 120 generates information indicating the portion where the reinforcement state indicated by the measurement values ​​differs from the reinforcement state indicated in the design information and the degree of the deviation, and sends the information to the output device 150. The output device 150 outputs a warning based on the information. The warning may be, for example, a display of an error message, a voice output, or the addition of additional information such as a flag to the recorded measurement result data.

[0043] <Details of Step S1200> Next, the operation of step S1200 will be described in detail with reference to Fig. 4. Fig. 4 is a flowchart showing the operation of step S1200 in detail. Step S1200 includes steps S1210, S1220, S1230, and S1240. The operation of each step will be described below.

[0044] (Step S1210) The processing device 120 determines the scope of the reinforcement inspection based on the design drawing indicated by the design information. For example, the scope of the reinforcement inspection may be determined by the user inputting information specifying an area, such as a floor or direction, to be inspected via the input device 140. The input device 140 may include a display means such as a display and an input means such as a pointing device. In this case, the design drawing may be displayed as a two-dimensional or three-dimensional drawing, and the user may specify a specific area in the displayed drawing, thereby setting the area as the reinforcement inspection scope. The scope of the reinforcement inspection may also be determined by other methods. For example, the processing device 120 may acquire position information of the 3D scanner 110 and, based on the position information, automatically determine a specific area in the design drawing that is close to the position of the 3D scanner 110 as the reinforcement inspection scope.

[0045] (Step S1220) The processing device 120 extracts structures such as columns, beams, slabs, and walls that are included in the range of the design drawing determined in step S1210. The processing device 120 determines whether or not reinforcing bars are included in each structure based on the design information, and extracts structures that include reinforcing bars as inspection targets.

[0046] (Step S1230) The processing device 120 divides the area of ​​the structure extracted in step S1220 into individual structure areas, and sets each structure as one unit of three-dimensional measurement.

[0047] (Step S1240) The processing device 120 assigns an inspection order to the structures that are the measurement targets. The order may be assigned, for example, in order of area size. Alternatively, the largest area may be the first measurement target, and the second and subsequent areas may be selected so that the center position of the area closest to the center position of the area immediately preceding the measurement target area is located. The inspection order may also be determined by other methods. In this way, the measurement order for each structure is determined. Information that specifies the measurement order for each structure determined in this way is called a "measurement plan."

[0048] <Details of Step S1400> Next, the operation of step S1400 will be described in detail with reference to Fig. 5. Fig. 5 is a flowchart showing the details of the operation of step S1400. Step S1400 includes steps S1410, S1420, and S1430. The operation of each step will be described below.

[0049] (Step S1410) The processing device 120 selects a measurement range in accordance with the measurement plan set in step S1200, and stores design information of the measurement range in the storage device 114 of the 3D scanner 110.

[0050] (Step S1420) The processing device 120 instructs the 3D scanner 110 to perform a primary scan that roughly scans the measurement range. The 3D scanner 110 roughly scans the measurement range selected in step S1410 to acquire three-dimensional position information of the measurement range. The 3D scanner 110 performs three-dimensional measurement by changing the direction of light emitted from the optical deflector 112. The scanning angle range is set so that the measurement range selected in step S1410 is included in the scanning range. The interval of the light irradiation angle can be set based on the information on the rebar spacing included in the design information and the standard value of the measurement distance range. For example, if the rebar spacing indicated in the design information is 300 mm and the standard measurement distance is 2000 mm, the interval of the irradiation angle corresponding to the rebar spacing is tan -1 (300 / 2000) This value is approximately 8.5 degrees. Therefore, in this case, in order to roughly measure the rebars and non-rebars, the interval of the irradiation angle can be set to a value smaller than 8.5 degrees, which corresponds to the predicted interval between the rebars.

[0051] (Step S1430) The processing device 120 detects the rough shape of the structure within the inspection range and the unevenness of the structure's surface based on the results of the 3D measurement performed in step S1420. Based on the detected rough shape of the structure and the unevenness of the structure's surface, the processing device 120 determines the rough positions of the concrete parts and rebar parts in the background or around the rebar.

[0052] The scanning operation for the rough three-dimensional measurement performed in step S1420 may be a raster scan or a Lissajous scan. Whether a raster scan or a Lissajous scan is performed, the irradiation angle for each measurement is determined so that the difference between two irradiation angles corresponding to two consecutive measurements is smaller than the angle corresponding to the predicted rebar spacing (e.g., 8.5 degrees). When a Lissajous scan is performed, the parameters of the Lissajous function are determined and the scan of the inspection range is performed so that such a condition is satisfied.

[0053] <Details of Step S1500> Next, the operation of step S1500 will be described in detail with reference to Fig. 6. Fig. 6 is a flowchart showing the details of the operation of step S1500. Step S1500 includes steps S1510, S1520, and S1530. The operation of each step will be described below.

[0054] (Step S1510) The processing device 120 determines an area where reinforcing bars are likely to exist based on the rough three-dimensional position information obtained in step S1400. The processing device 120 calculates the existence probability of reinforcing bars based on the approximate positions of the reinforcing bars indicated by the three-dimensional position information, and determines an area where the existence probability exceeds a threshold as an area where reinforcing bars are likely to exist.

[0055] Here, the two axes of scanning motion of the 3D scanner 110 are the x-axis and the y-axis. When the 3D scanner 110 is installed on a horizontal plane, the x-axis is parallel to the horizontal plane and the y-axis is perpendicular to the horizontal plane. The processing device 120 calculates, for example, the probability of the presence of rebar for each region on the plane defined by the x-axis and y-axis.

[0056] FIG. 7 is a diagram showing the rebar presence probability for each region. The horizontal axis represents the axis parallel to the x-axis, and the vertical axis represents the axis parallel to the y-axis. The "x" marks indicate the positions of measurement points 220 obtained by the coarse scan in step S1400. The thick lines indicate the positions of rebars 210. In FIG. 7, the leftmost measurement point 220A and the third measurement point 220B from the right have different depth positions perpendicular to the x-axis and y-axis from the positions of the surrounding measurement points 220, and are therefore likely to be rebars. The processing device 120 generates a distribution of rebar presence probability on the xy plane by setting the distribution of rebar presence probability along the x-axis and y-axis based on the positions of these points that may be rebars. In FIG. 7, the distribution of rebar presence probability P is expressed as a normal distribution as an example. Regions 230 where this presence probability P exceeds a threshold value Th can be determined as regions where rebars are likely to be present.

[0057] The determination of the possibility of the presence of rebars may be performed by other methods. For example, based on the spacing of rebars shown on the design drawings and the point cloud data obtained by a coarse scan, a grid-like area that best matches the positions of measurement points (hereinafter also referred to as "data points") estimated to be at the locations of rebars may be set as an area with a high probability of the presence of rebars. Alternatively, a method may be used in which the likelihood of the presence of rebars is calculated by machine learning or statistical learning using the information on the design drawings and the point cloud data obtained by a coarse scan.

[0058] (Step S1520) The processing device 120 determines a scanning trajectory, which is realized by changing the irradiation angle around two orthogonal axes, such as a raster scan or a Lissajous scan, and generates a list of scanning directions. The scanning direction can be expressed as an angle along each of the x-axis and y-axis relative to a reference direction (e.g., the front direction). The processing device 120 sets the angles of the x-axis and y-axis so that the density of measurement points is high when the trajectory passes through an area where the probability or likelihood of rebar existence is high, and the density of measurement points is low when the trajectory passes through an area where the probability or likelihood of rebar existence is low.

[0059] (Step S1530) The processing device 120 determines the order of irradiation directions by arranging the sets of angles of the x-axis and y-axis determined in S1520 along the trajectory of a scan such as a raster scan or a Lissajous scan.

[0060] The process of step S1520 is effective when a scan, such as a galvanometer scan, is performed, in which the moving speed of the scan measurement position can be adjusted. When using a scanner, such as a MEMS mirror, in which precise adjustment of the measurement position is difficult, a two-dimensional distribution of the probability or likelihood of the presence of rebars can be determined as in step S1510 above. In step S1520, the measurement area can be divided into multiple small areas according to the two-dimensional distribution of the probability or likelihood, and measurement points can be set for each small area according to the probability or likelihood of the presence of rebars. A scan setting can be implemented in which the spatial density of measurement points is increased in small areas with a higher probability or likelihood of the presence of rebars, and decreased in small areas with a lower probability or likelihood. In this case, in step S1530, the order of measurements for the divided multiple small areas is determined.

[0061] In this way, in this embodiment, the irradiation direction of the detailed scan is determined according to the arrangement of the rebars, which shortens the measurement time and reduces the amount of data in the measurement results compared to when detailed scans are performed over the entire measurement area.

[0062] Regarding the calculation of the rebar presence probability in step S1510, the thicker the rebar, the more likely it is to be measured during a coarse scan, and the wider the range in the thickness direction where the rebar presence probability is greatest, resulting in differences in the presence probability function. Therefore, when calculating the presence probability of rebars in the measurement target range, the presence probability distribution function to be used may be changed according to the rebar thickness. Alternatively, the presence probability distribution function according to the rebar thickness may be selected from multiple distribution functions. When point cloud data obtained by a coarse scan is used as preliminary data as in this embodiment, the thickness of the rebar can be determined based on design information. The design information may include information on the presence probability distribution function to be used in the calculation.

[0063] When image data is used as preliminary data, as in the third embodiment described below, the thickness may be determined from the range of thicknesses expressed as the number of pixels in the rebar region in the image or the relative distance in the image. In this case, the relationship between the distance between the camera and the object and the distance between pixels in the captured image is stored in advance in a storage device. For a rebar region extracted from a captured image using processing such as image recognition, the number of pixels in the thickness direction and the distance obtained by rough scanning measurement can be used to estimate the range of thicknesses of the rebar, for example, between 2 cm and 3 cm. Even if the distance to the object is unknown and the thickness of the rebar cannot be estimated from the number of pixels, the approximate distance between pixels can be estimated from the size of known objects surrounding the rebar region, thereby estimating the thickness of the rebar. For example, if the width of a pillar is estimated to be 90 cm and the number of pixels in the thickness direction of the rebar region is approximately 1 / 30 of the number of pixels in the pillar width, the thickness of the rebar can be estimated to be approximately 3 cm.

[0064] <Details of step S1700> Next, the operation of step S1700 will be described in detail. Fig. 8 is a flowchart showing the details of the operation of step S1700. Step S1700 includes steps S1710, S1720, and S1730. The operation of each step will be described below.

[0065] (Step S1710) The processing device 120 converts the three-dimensional point cloud data obtained in step S1600 from the coordinate system of the 3D scanner 110 to the coordinate system of the design drawing, and associates the position of the structure in the design drawing with the measurement area.

[0066] (Step S1720) The processing device 120 extracts a group of points arranged in a straight line as a group of points corresponding to a reinforcing bar. When a line is fitted to the group of points arranged in a straight line and the line is extended into space, the group of points located on or near the line is collectively identified as a single reinforcing bar.

[0067] This allows rebars that are not measured due to occlusion and whose actual length or thickness is unknown to be treated as a single long rebar, making it possible to calculate the inclination and rebar density. An example of occlusion occurring is when horizontally extending rebars or other planar components are placed in front of vertically extending rebars placed in a column. In such cases, 3D measurement of part of the vertically extending rebar is impossible due to the horizontally extending rebars or other components. In such cases, the method of identifying the rebar by fitting a straight line is effective.

[0068] (Step S1730) The processing device 120 determines whether each rebar identified in step S1720 matches the position and thickness specified in the design drawing. The processing device 120 calculates the slope from the parameters of the line used to identify the rebar and determines whether there is any deviation from the design drawing. The processing device 120 determines whether there are any points around the line that deviate from the line used to identify the rebar. If there are any deviating points, the processing device 120 determines whether the positions of those points match the joint positions in the design drawing. If the points are deviating points far from the joint positions, the processing device 120 determines that there is a bend. The processing device 120 determines the positions of the rebars within the measurement range from the arrangement of the lines identified as rebars, and calculates the spacing between the rebars and the number of vertical and horizontal rebars located within a certain range, for example, a 1-meter square range from the surface of the structure. The processing device 120 determines whether the conditions for the rebars to be installed in the structure specified in the design drawing are met.

[0069] In this way, even if there is a lack of positional information for the rebars due to occlusion, by applying a straight line and grouping them, it is possible to identify the rebars measured as multiple point cloud groups as a single rebar. The straight line can compensate for the lack of positional information due to occlusion, and it is possible to estimate the spacing and number of rebars even in areas where there are no measurements. This eliminates the need to remeasure from a different direction, reducing the labor required for inspection.

[0070] After the processing device 120 selects the measurement area in step S1400, it may be necessary to adjust the 3D scanner 110 to a position and orientation that allows measurement of the measurement area. To handle such cases, the reinforcement arrangement inspection system 100 may be provided with a mechanism for moving the position and orientation of the 3D scanner 110. Alternatively, the 3D scanner 110 may be provided with a mechanism for automatically moving or changing its orientation. Instead of providing such a mechanism, the user may move the 3D scanner 110, determine its orientation, and then install it. When the user moves the 3D scanner 110 and determines its orientation, the processing device 120 may display information to guide the user on a display based on a design drawing.

[0071] As described above, the reinforcing bar arrangement inspection system 100 of this embodiment includes a 3D scanner 110, a processing device 120, and an output device 150. The 3D scanner 110 acquires 3D information of a structure including reinforcing bars. The processing device 120 acquires preliminary data regarding the arrangement of reinforcing bars and design information for the reinforcing bars, and configures the measurement operation of the 3D scanner based on the preliminary data. The processing device 120 compares the 3D information acquired by the 3D scanner 110 through the measurement operation based on the configuration with the design information. The output device 150 outputs the results of the reinforcing bar arrangement inspection based on the comparison results. The preliminary data in this embodiment includes preliminary 3D information acquired by the 3D scanner before configuring the measurement operation. The preliminary 3D information is information indicating the 3D positions of multiple measurement points acquired by roughly measuring the target of the reinforcing bar arrangement inspection in 3D. The spatial density of the measurement points in the preliminary 3D information is lower than the spatial density of the measurement points in the 3D information acquired through the measurement operation based on the configuration. The spacing between measurement points in the preliminary 3D information is narrower than the spacing between rebars indicated in the design information. The processing device 120 calculates the probability or likelihood of the presence of rebars based on preliminary data, i.e., the preliminary 3D information and / or the design information. The processing device 120 may correct the probability or likelihood of the presence of rebars according to the thickness of the rebars. The processing device 120 sets the measurement operation of the 3D scanner 110 based on the probability or likelihood of the presence of rebars. That is, the processing device 120 plans and sets detailed scanning operations to identify the detailed position and shape of rebars required for rebar inspection based on the probability or likelihood of the presence of rebars. The processing device 120 identifies rebars by fitting a straight line to the point cloud acquired by the detailed scan. This makes it possible to obtain information on the position and shape of rebars by compensating for loss of spatial position information due to occlusion, thereby enabling appropriate rebar inspection.

[0072] Note that the rough distance measurement results obtained by the primary scan in step S1400 may differ between the measured distance of the rebar and the measured distance of the background or surrounding concrete, etc. In this case, the processing device 120 may perform a detailed scan by adjusting the focal length of the laser light of the LiDAR sensor 111 to the measured distance of the rebar obtained by the primary scan. The processing device 120 may automatically focus the LiDAR sensor 111 or may output a message on the display prompting the user to focus. This allows the focus of the irradiated light to be aligned with the position of the rebar, thereby increasing the intensity of the reflected light and improving measurement accuracy.

[0073] Furthermore, if there is variation in the distances of the reinforcing bar positions detected in step S1400, i.e., if the distances of the reinforcing bars within the measurement range are not uniform, when planning the scan in step S1500, in addition to the probability or likelihood of the existence of reinforcing bars on the x and y axes, the probability or likelihood may also be calculated on the z axis in the depth direction to set the scan operation.

[0074] In the example shown in Figure 6, in step S1520, the scan area is not divided when a scanner capable of adjusting the scanning movement speed, such as a galvano scan, is used, but this is not a limitation. Regardless of the type of scanner, the scan area may be divided into multiple small areas based on the distance range for areas with a high probability or likelihood of the presence of rebars. By dividing the scan area based on distance, the laser focal length can be adjusted to the distance to the rebars for each scan area, further improving measurement accuracy.

[0075] [Embodiment 2] Next, a reinforcement bar inspection system according to a second exemplary embodiment of the present disclosure will be described. In the first embodiment, a 3D scanner 110 performs a rough primary scan with low spatial density based on a design drawing, and generates preliminary data including preliminary 3D information for grasping the outline of the rebar positions. In contrast, in the reinforcement bar inspection system of this embodiment, the preliminary data is generated based on design information. For example, the preliminary data is generated based on coordinate information obtained from a Global Navigation Satellite System (GNSS) and design information accompanied by detailed GNSS coordinate information. The following description will focus on differences from the first embodiment, and overlapping descriptions will be omitted.

[0076] <Configuration> Fig. 9 is a block diagram showing a schematic configuration of a bar arrangement inspection system 100 according to this embodiment. The bar arrangement inspection system 100 shown in Fig. 9 includes a GNSS unit 160 that acquires position information by GNSS, in addition to the components of the bar arrangement inspection system 100 shown in Fig. 1A. Except for the addition of the GNSS unit 160, the configuration of this embodiment is similar to the configuration shown in Fig. 1.

[0077] GNSS is a general term for satellite positioning systems such as GPS (Global Positioning System), QZSS (Quasi-Zenith Satellite System), GLONASS, Galileo, and BeiDou. The GNSS unit 160 acquires position information for the 3D scanner 110 using any of these satellite positioning systems. The GNSS unit 160 may be configured to perform high-precision positioning using, for example, RTK (Real Time Kinematic)-GNSS. Positioning using RTK-GNSS uses satellite signals transmitted from multiple GNSS satellites as well as correction signals transmitted from a reference station. The reference station may be installed near (for example, within 10 km of) the site where the reinforcement bar arrangement inspection is to be performed. The reference station generates correction signals based on satellite signals received from multiple GNSS satellites and transmits them to the GNSS unit 160. The GNSS unit 160 corrects the positioning results based on the correction signals, enabling high-precision positioning with an error of, for example, several centimeters. The positioning method is not limited to RTK-GNSS, and any positioning method that can obtain position information with the required accuracy can be used.

[0078] The GNSS unit 160 acquires detailed position information on a world coordinate system of the position where the 3D scanner 110 is installed. The GNSS unit 160 acquires, for example, latitude and longitude information. The GNSS unit 160 may be configured to acquire altitude (i.e., elevation) information in addition to latitude and longitude.

[0079] In this embodiment, the design information also includes GNSS coordinate information. That is, the design information includes detailed coordinate information of each point of each structure, including the rebar. Such design information is stored in the storage device 130 or input from an external device via the input device 140.

[0080] In addition to planning the scanning operation and processing the data acquired by the 3D scanner 110, the processing device 120 in this embodiment determines the position and orientation of the 3D scanner 110 and calculates the approximate position of the rebar based on the coordinate information acquired from the GNSS unit 160 and design information including GNSS coordinate information acquired from the input device 140 or the storage device 130.

[0081] When the GNSS unit 160 acquires the latitude, longitude, and altitude of the position of the 3D scanner 110, the design information may describe the latitude, longitude, and altitude for at least each structure, such as a pillar or beam, with the same level of accuracy as the GNSS unit 160. Alternatively, the design information may include information on a function that converts the position information of each structure into GNSS coordinates. This allows the processing device 120 to compare the position information acquired by the GNSS unit 160 with the position information of each structure included in the design information.

[0082] <Operation> Fig. 10 is a flowchart showing the operation of the bar arrangement inspection system 100 according to the second embodiment. In Fig. 10, the same operations as those shown in Fig. 3 are denoted by the same reference numerals. Hereinafter, the operation of the bar arrangement inspection system 100 according to this embodiment will be described with reference to Fig. 10. Detailed description of the same operations as those shown in Fig. 3 will be omitted.

[0083] (Step S1100) The processing device 120 acquires the design information from the storage device 130 or the input device 140. The design information in this embodiment includes detailed GNSS coordinate information of each structure.

[0084] (Step S5200) The processing device 120 creates a measurement plan for the 3D point cloud data based on the design information. From among the structures indicated by the acquired design information, structures that include reinforcing bars are identified. Based on the GNSS coordinate information included in the design information, an installation range for the 3D scanner 110 is set on the GNSS coordinate system near each structure to be measured. The operation of setting the installation range will be described in detail later.

[0085] (Step S1300) The processing device 120 determines whether all measurements indicated in the measurement plan set in step S5200 have been completed or whether an end signal instructing the end of measurement has been input. If measurements of all planned areas have been completed or an end signal has been input, the reinforcement arrangement inspection system 100 ends its operation. If measurements of all planned areas have been completed and an end signal has not been input, the process proceeds to step S1400.

[0086] (Step S5400) The processing device 120 selects a measurement target structure that has not yet been measured according to the measurement plan set in step S5200. For the selected structure, the 3D scanner 110 is installed within the installation range set in step S5200. The 3D scanner 110 may be configured to move automatically using a moving means (not shown). Alternatively, the processing device 120 may guide the user to install the 3D scanner 110 within the installation range by displaying the installation range via the output device 150 or by providing voice instructions on the direction of movement. The user can move the 3D scanner 110 within the installation range according to the instructions and install the 3D scanner 110 in an orientation that allows measurement of the structure. When the 3D scanner 110 moves automatically, for example, the GNSS coordinates acquired by the GNSS unit 160 may be compared with the GNSS coordinates of the installation range set in step S5200, and the movement direction may be determined based on the comparison result.

[0087] (Step S5500) The processing device 120 determines the rebar area based on the arrangement of the rebars in the design information and sets an operation plan for detailed scanning. The processing device 120 determines the irradiation angle for detailed scanning of the rebar area or divides the area into multiple scan areas. Details of how to determine the irradiation angle or divided areas will be described later.

[0088] (Step S1600) The processing device 120 causes the 3D scanner 110 to perform a detailed scan. The 3D scanner 110 performs detailed 3D measurements of the structure, including the rebars, in the area in accordance with the scan plan set in step S1500. As a result, 3D point cloud data including 3D position information of multiple reflection points is acquired.

[0089] (Step S1700) The processing device 120 identifies the position of the rebars based on the three-dimensional position information acquired in step S1600. Based on the identified position and shape of each rebar, the processing device 120 calculates physical quantities such as the inclination, curvature, thickness, spacing between rebars, and / or the average number of rebars per reference area of ​​each rebar, and sets these as measurement values. The processing device 120 compares the measurement values ​​with design values.

[0090] (Step S1800) The processing device 120 determines whether there is a discrepancy between the measured value indicating the reinforcement state calculated in step S1700 and the design value indicated by the design information. Whether there is a discrepancy can be determined based on whether the difference between the measured value and the design value is greater than a threshold. If there is no discrepancy between the measured value and the design value, the process proceeds to step S1900. If there is a discrepancy between the measured value and the design value, the process proceeds to step S3800.

[0091] (Step S1900) The output device 150 generates and outputs output data including measurements such as the position, shape, inclination, curvature, thickness, spacing, and / or average number of rebars.

[0092] (Step S3800) The processing device 120 determines whether or not this is the first measurement of the measurement range. If two or more measurements have been performed on the measurement range, the process proceeds to step S2100. If this is the first measurement of the measurement range, the process proceeds to step S3900. The process of step S3800 is performed to change the measurement position and re-detect any rebars that could not be detected correctly in the first measurement due to occlusion.

[0093] (Step S3900) The processing device 120 performs processing to change the measurement position of the 3D scanner 110. In step S1800, if the number of rebars is less than the number in the design drawing, and the direction of the fewer rebars is parallel to the x-axis, the position of the 3D scanner 110 is changed in the y-axis direction. If the direction of the fewer rebars is parallel to the y-axis, the position of the 3D scanner 110 is changed in the x-axis direction. As described above, the change in the position of the 3D scanner 110 may be manual or automatic. After the position of the 3D scanner 110 has been changed, the process returns to step S5500.

[0094] (Step S2100) The processing device 120 identifies the portion where the results of the 3D measurement taken in step S1600 differ from the design information of the region. The processing device 120 generates information indicating the portion where the reinforcement state indicated by the measurement value differs from the reinforcement state indicated in the design information and the degree of the deviation, and sends the information to the output device 150. The output device 150 outputs a warning based on the information.

[0095] <Details of step S5200> Next, the operation of step S5200 will be described in detail. Fig. 11 is a flowchart showing the details of the operation of step S5200. Step S5200 includes steps S5210 to S5240. The operation of each step will be described below.

[0096] (Step S5210) The processing device 120 obtains the GNSS coordinates of the current position of the 3D scanner 110 from the GNSS unit 160.

[0097] (Step S5220) The processing device 120 compares the current position of the 3D scanner 110 acquired in step S5210 with the GNSS coordinate information described in the design information to identify the range of the reinforcement inspection in the design drawing. For example, a predetermined range on a horizontal plane centered on the GNSS coordinates of the current position of the 3D scanner 110 is set as the inspection range. As described above, the GNSS unit 160 may have the function of measuring and outputting altitude, and the design information may include altitude information in addition to the GNSS coordinates of the horizontal plane. In that case, the processing device 120 may identify the floor on which the 3D scanner 110 is installed based on the GNSS coordinates of the current position of the 3D scanner 110 and the altitude, and limit the inspection range to that floor.

[0098] (Step S5230) Based on the design drawings, the processing device 120 extracts structures included in the inspection range determined in step S5220, and designates those structures that contain rebar as inspection targets. Each of the structures determined as inspection targets is treated as a unit of inspection, and the inspection order of multiple structures is determined. The inspection order can be determined by a method in which the structure closest to the current position of the 3D scanner 110 is designated as the first inspection target, and from the second onwards, the structure closest to the position of the inspection target is designated as the next measurement target, and the inspection order of all inspection targets is determined.

[0099] (Step S5240) The processing device 120 sets the installation range of the 3D scanner 110 for each structure to be inspected determined in step S5230. The installation range can be set, for example, by the following method. First, the processing device 120 identifies the position of the surface of the structure to be measured based on the design drawing. The installation range of the 3D scanner 110 is set to a certain distance range on the horizontal plane from the position of the surface of the structure.

[0100] FIG. 12 is a schematic diagram illustrating an example of an installation range of an inspection target structure and the 3D scanner 110. In FIG. 12, a range 260 indicated by a dotted line around a pillar 250, which is an example of a structure, can be set as the installation range of the 3D scanner 110. In the example of FIG. 12, a columnar spatial range 260 within a certain distance on a horizontal plane from the finished surface of the rectangular pillar 250 is set as the installation range. Since this installation range is an area where the 3D scanner 110 should be installed, no restrictions are placed on the height direction. Based on the horizontal cross-sectional shape of the inspection target pillar 250, a certain distance on a horizontal plane from the surface is set in accordance with the characteristics of the 3D scanner 110. The characteristics considered here can be, for example, the ranging range of the 3D scanner 110. The certain distance can be set to a distance shorter than the ranging range of the 3D scanner 110. Here, an example of a method for determining the installation range when the 3D scanner 110 is used in a fixed state on a flat surface has been described, but the method is not limited to such a method. For example, when the 3D scanner 110 is mounted on a mobile body that moves three-dimensionally, such as a drone, and an installation plane is not required, the installation range may not be fixed to a horizontal plane, but may be set as an area within three-dimensional space.

[0101] The processing device 120 may set the installation range of the 3D scanner 110 each time according to the characteristics of the 3D scanner 110. Alternatively, the processing device 120 may calculate the installation range of the 3D scanner 110 in advance based on the performance of a specific 3D scanner, a 3D scanner having performance defined by a standard, or an average 3D scanner, and information about the installation range may be described in advance in the design information.

[0102] <Details of step S5400> Next, the operation of step S5400 will be described in detail. Fig. 13 is a flowchart showing the details of the operation of step S5400. Step S5400 includes the following steps S5410 and S5420.

[0103] (Step S5410) The processing device 120 selects a structure to be measured in accordance with the inspection order determined in step S5200. The processing device 120 acquires design information of the structure and information on the installation range of the 3D scanner 110.

[0104] (Step S5420) The 3D scanner 110 is moved within an installation range associated with the structure to be measured, and is installed so that the 3D scanner 110 faces the direction of the structure. The processing device 120 may automatically control the movement of the 3D scanner 110 based on the GNSS coordinates, or may output instructions via a display or audio output device to prompt the user to move the 3D scanner 110 and adjust its orientation.

[0105] <Details of step S5500> Next, the operation of step S5500 will be described in detail. Fig. 14 is a flowchart showing the details of the operation of step S5500. Step S5500 includes the following steps S5510 to S5560.

[0106] (Step S5510) The processing device 120 extracts information about the position and shape of the reinforcing bars, such as their thickness, from the design information of the structure to be measured acquired in step S5400.

[0107] (Step S5520) The processing device 120 places the rebar positions in the design drawings on a 3D map based on GNSS coordinates. This 3D map is a virtual map referenced in the internal processing of the processing device 120. The processing device 120 also places the GNSS coordinates of the current position of the 3D scanner 110, acquired in step S5200, on the 3D map.

[0108] (Step S5530) The processing device 120 sets the rebar presence probability distribution on the 3D map by setting the rebar positions in the design drawings as the positions with the highest rebar presence probability. The processing device 120 determines the scan area of ​​the measurement target based on the rebar presence probability distribution. The method for setting the presence probability distribution is the same as the method in embodiment 1 shown in Figure 7.

[0109] (Step S5540) The processing device 120 divides the scan area of ​​the measurement target based on the rebar existence probability distribution set in step S5530 into multiple areas based on the extension direction of the rebars. That is, the processing device 120 divides the inspection area into vertically extending rebars and horizontally extending rebars. As a result of the area division, overlapping of the areas may occur at the intersections of the rebars.

[0110] (Step S5550) The processing device 120 sets the interval of the irradiation angle for each region divided in step S5540, providing the resolution necessary to acquire information about the thickness and shape of the rebar. More specifically, the processing device 120 determines the interval of the irradiation angle for an axis perpendicular to the direction of extension of the rebar, providing the resolution necessary to measure the thickness of the rebar. Furthermore, the processing device 120 sets the interval of the irradiation angle for an axis parallel to the direction of extension of the rebar, providing the resolution necessary to measure the detailed shape of the rebar, such as its inclination and bending. The processing device 120 determines the distance between the rebar shown in the design drawing and the 3D scanner 110 on the 3D map created in steps S5520 and S5530. Based on this distance, the processing device 120 calculates the interval of the irradiation angle for measuring the thickness of the rebar with an accuracy of, for example, 0.5 mm or less. Based on this distance, the processing device 120 also calculates the interval of the irradiation angle for measuring the inclination and bending of the rebar with an accuracy of, for example, 2 mm or less.

[0111] (Step S5560) The processing device 120 applies the irradiation angle intervals set in step S5550 to the individual regions divided based on the rebar orientation in step S5540, and determines scan parameters for each of the x- and y-axes according to the rebar orientation in each region. The scan parameters may include, for example, the scan angle range, scan point density, scan trajectory, and scan speed for each of the x- and y-axes. The scan parameters may also include voltage or current values ​​as control signals for achieving the desired scan operation. As described above, the scan method may be raster scanning or Lissajous scanning.

[0112] As described above, according to this embodiment, the processing device 120 generates a 3D map as preliminary data based on the GNSS coordinates of the 3D scanner 110 and design information describing the GNSS coordinates of each structure. The 3D map includes GNSS coordinate information of the structure to be inspected, which is included in the design information, and GNSS coordinate information of the current position of the 3D scanner 110, which is acquired by the GNSS unit 160. By using the 3D map data as preliminary data, the processing device 120 can set a scan plan for obtaining measurement data with the accuracy or resolution required for reinforcement inspection in areas where there is a high probability of rebar presence.

[0113] Furthermore, even if the number of rebars identified through 3D measurement is less than the number described in the design drawings, the rebars can be identified more accurately by moving the 3D scanner 110 and measuring again. For example, if multiple rebars extending in the same direction overlap in the direction of light emitted from the 3D scanner 110, making it impossible to distinguish between the two rebars, or if one rebar is obscured by another rebar and the emitted light does not reach it, i.e., occlusion occurs, the 3D scanner 110 can be moved, for example, by a minimal amount, and measurements can be taken again. This allows for more accurate generation of 3D position data without occlusion-related defects, with fewer measurements. As a result, the position and shape of the rebars can be measured more efficiently, enabling highly accurate bar arrangement inspections in a shorter time.

[0114] [Embodiment 3] Next, a reinforcement bar inspection system according to a third exemplary embodiment of the present disclosure will be described. In the first embodiment, a 3D scanner 110 performs a rough primary scan with low spatial density based on a design drawing to generate preliminary data for grasping the general location of rebars. In the second embodiment, the preliminary data is generated based on GNSS coordinate information and design information accompanied by detailed GNSS coordinate information. In this embodiment, the preliminary data is generated based on image information of a structure acquired by a camera. The following description will focus on differences from the first embodiment, and overlapping descriptions will be omitted.

[0115] <Configuration> Fig. 15 is a block diagram showing a schematic configuration of a bar arrangement inspection system 100 according to this embodiment. The bar arrangement inspection system 100 shown in Fig. 15 includes a camera 170, i.e., an imaging device, in addition to the components of the bar arrangement inspection system 100 shown in Fig. 1A. Except for the addition of the camera 170, the configuration of this embodiment is the same as the configuration shown in Fig. 1.

[0116] The camera 170 and the 3D scanner 110 are arranged to face in the same direction. That is, the two-dimensional image captured by the camera 170 and the three-dimensional point cloud data measured by the 3D scanner 110 show measurement results in approximately the same direction. The parallax between the two-dimensional image and the three-dimensional point cloud data is fixed. The parallax is determined in advance, and the transformation formula and parameters for projecting the three-dimensional coordinates in the three-dimensional point cloud data onto pixels on the two-dimensional image are also determined in advance. Because the parallax between the camera 170 and the 3D scanner 110 is fixed, an orientation sensor such as a gyro sensor may be provided in either the camera 170 or the 3D scanner 110.

[0117] Fig. 16A is a block diagram showing an example of a configuration in which the bar arrangement inspection system 100 is provided with a camera system 180 including a camera 170 and an orientation sensor 115. Fig. 16B is a block diagram showing an example of a configuration in which the 3D scanner 110 is provided with the orientation sensor 115. The orientation sensor 115 may include, for example, a gyro sensor and / or an acceleration sensor. The orientation sensor 115 generates a signal indicating the tilt of the camera 170 and / or the 3D scanner 110 and transmits the signal to the processing device 120. Based on the signal, the processing device 120 can control actuators to adjust the orientations of both the camera 170 and the 3D scanner 110, or correct the direction of light irradiation in accordance with the tilt.

[0118] <Operation> Fig. 17 is a flowchart showing the operation of the bar arrangement inspection system 100 according to the third embodiment. In Fig. 17, the same operations as those shown in Fig. 3 are denoted by the same reference numerals. Hereinafter, the operation of the bar arrangement inspection system 100 according to this embodiment will be described with reference to Fig. 17. Description of operations similar to those shown in Fig. 3 will be omitted.

[0119] In this embodiment, after steps S1100 and S1200, if it is determined in step S1300 that the measurement has not ended, the process proceeds to step S3400.

[0120] (Step S3400) The processing device 120 acquires an image including the inspection area photographed by the camera 170, and performs processing to identify an area in the image where reinforcing bars exist. Details of the operation of step S3400 will be described later.

[0121] (Step S3500) Based on the processing result of step S3400, the processing device 120 sets an operation plan for detailed scanning, that is, the light irradiation angles and the order thereof, for acquiring three-dimensional information about the reinforcing bars in the identified region.

[0122] (Step S3700) The processing device 120 identifies the position and shape of the rebars based on the 3D position information obtained in step S1600. The processing device 120 associates the identified position and shape of the rebars with the position and shape of the rebars shown in the design drawing. The processing device 120 compares the 3D position information of each rebar with the design drawing and confirms the inclination, bending, and thickness of each rebar. The processing device 120 also divides the measurement area into specified volumes or surface areas and calculates the spacing and number of rebars. The operation of step S3700 will be described in detail later.

[0123] When identifying the shape of each rebar based on its 3D position information, the detailed thickness of the rebar may be determined using the image recognition results in step S3400 or edges identified based on brightness or color information of the image obtained in step S3400. The fields of view of the camera 170 and the 3D scanner 110 are pre-assigned by calibration. However, in many cases, the number of pixels of the camera 170 is greater than the number of data points of the 3D scanner 110. Therefore, when the 3D point cloud data acquired by the 3D scanner 110 is projected onto a 2D image acquired by the camera 170, the accuracy of the 2D position information converted from the 3D point cloud data is lower than that of the 2D position information of the original image data due to the low position resolution of the 3D point cloud data. For example, in the process of projecting 3D position information onto 2D pixel positions, 3D coordinates are projected onto 2D coordinates using a predetermined conversion formula. When generating information on each x- and y-coordinate position in an acquired 2D image, such as color information, it is possible to interpolate information on missing x- and y-coordinates based on the coordinate position from multiple pixels with nearby values, or to use information on the pixel with the value closest to that x- and y-coordinate position. However, in reinforcement inspection, the shape of the reinforcement is an important inspection item, and accuracy is required. For this reason, in this embodiment, the accuracy of shape information such as the thickness of the rebar is improved by using information on pixel positions in the image using the following method.

[0124] The processing device 120 performs the following processing on each data point for which three-dimensional position information has been acquired. First, the processing device 120 projects three-dimensional coordinates onto two-dimensional coordinates using a predetermined conversion formula. The processing device 120 also extracts boundary pixels of the rebar area based on the image data. The processing device 120 may identify the rebar area and extract its boundary pixels using image recognition processing, or may extract edge pixels as boundary pixels of the rebar using image processing for edge extraction. The processing device 120 then matches the boundary pixels of the rebar area closest to the two-dimensional coordinates projected from the three-dimensional position coordinates. The processing device 120 measures the thickness of the rebar based on the coordinates of the pixels that correspond to the three-dimensional position in the image data. Using the three-dimensional position information that was the basis for the projection onto the two-dimensional plane, the thickness of the rebar can be accurately calculated based on the number of pixels on the axis in the thickness direction of the rebar, based on the distance from the 3D scanner 110. The correspondence between the number of pixels and the length according to the distance may be defined in a conversion function or data such as a table prepared in advance, and this information may be stored in the storage device 130 in advance.

[0125] <Details of Step S3400> The operation of step S3400 will be described in detail below. Figure 18 is a flowchart showing the details of the operation of step S3400. Step S3400 includes the following steps S3410 to S3440.

[0126] (Step S3410) The processing device 120 determines the measurement range based on the measurement plan set in step S1200. The position and orientation of the camera 170 are adjusted so that an image of the measurement range can be acquired. The adjustment may be performed automatically or by the user. If the adjustment is performed by the user, the processing device 120 may present an image or sound via a display or audio output device to guide the user in adjusting the position and orientation of the camera 170. The processing device 120 may present information to the user instructing them to complete the setting when the measurement range falls within the angle of view of the camera 170.

[0127] (Step S3420) The processing device 120 instructs the camera 170 to take a photograph. In response to the instruction, the camera 170 takes a photograph of the measurement range and acquires a two-dimensional image of the measurement range. The camera 170 sends data of the two-dimensional image to the processing device 120.

[0128] (Step S3430) The processing device 120 performs edge extraction processing on the image acquired in step S3420.

[0129] (Step S3440) The processor 120 selects, from the edges extracted in step S3430, edges to which straight lines can be fitted as candidates for reinforcing bars, and determines pixel regions including the selected edges.

[0130] The series of operations in steps S3430 and S3440 described above is an example of a method for determining the position on the xy plane of an object that may be a rebar using image processing. Other methods may also be used. For example, two-dimensional frequency analysis may be performed on the image to determine areas with high spatial frequency as areas containing rebar. When multiple rebars are arranged parallel or crosswise, such areas frequently exhibit changes in the brightness or color contrast of the image. By identifying areas with frequent contrast changes through frequency analysis, areas containing rebar arrangements can be identified. Alternatively, for example, an image containing many rebar arrangements may be used to recognize rebars from the image using a pre-trained rebar recognition model, and the areas containing pixels occupied by the recognized rebars may be determined. A straight line model may be applied to each recognized rebar, and an image of multiple rebars arranged in a single line may be treated as an image of a single rebar, thereby determining the pixel area containing the rebar.

[0131] <Details of step S3500> Next, the operation of step S3500 will be described in detail. Figure 19 is a flowchart showing the details of the operation of step S3500. Step S3500 includes the following steps S3510 to S3530.

[0132] (Step S3510) The processing device 120 acquires position information on the xy plane of the area where the reinforcing bars are located, which was identified based on the image obtained in step S3400. Using a function that projects three-dimensional position coordinates onto a two-dimensional plane, the processing device 120 sets the range of light irradiation directions corresponding to each reinforcing bar area from the coordinate position on the xy plane of each reinforcing bar area.

[0133] (Step S3520) The processing device 120 sets the range of the light irradiation direction corresponding to the rebar area set in step S3510 as the scan range. If there are multiple rebar areas, the processing device 120 sets multiple scan ranges and determines the order in which to scan those scan ranges. The order may be determined, for example, in descending order of range. Alternatively, the widest scan range may be set first, and subsequent scan ranges may be selected that are closest to the previous scan range.

[0134] (Step S3530) The irradiation direction and the order within the scan range are determined for each scan range, i.e., for each rebar region. As described above, the scan method may be raster scan or Lissajous scan, or may be another method.

[0135] The processing device 120 may set the irradiation direction to perform a uniformly detailed scan for each scan range. If the direction of the rebars within the region is clear based on the image, the scanning irradiation direction may be set to increase the spatial density of measurement points in a direction perpendicular to the rebar direction. The scanning irradiation direction may be specified by the angle of two axes, the x-axis and the y-axis. Therefore, by adjusting the frequency of measurement points in the x-axis direction and the y-axis direction relative to the rebar direction, it is possible to set a scan that increases the spatial density of measurement points in a direction across the rebars even with the same number of measurement points.

[0136] When setting the irradiation direction, the scanning method may be determined, and the frequency of measurement points in the x-axis direction and the frequency of measurement points in the y-axis direction may be adjusted as conditions for determining the function parameters of the scanning operation. When raster scanning is performed, the scan range and the frequency of measurement points in each of the x-axis and y-axis directions may be set as the function parameters of the scanning operation. When Lissajous scanning is performed, parameters of the Lissajous waveform, such as the scan range in each of the x-axis and y-axis directions, the vibration frequency in each of the x-axis and y-axis directions, and the number of measurement points per unit time, may be set as the function parameters of the scanning operation.

[0137] <Details of step S3700> Next, the operation of step S3700 will be described in detail. Figure 20 is a flowchart showing the details of the operation of step S3700. Step S3700 includes the following steps S3710 to S3740.

[0138] (Step S3710) The processing device 120 associates the rebar area on the design drawing within the measurement area acquired in step S3400 with the measurement area. The processing device 120 identifies the structure extracted as the measurement area in step S1200 and the structure in the design drawing from the measurement order. Furthermore, the processing device 120 identifies the rebar area in the design drawing that corresponds to the scan range determined in step S3500.

[0139] (Step S3720) The processing device 120 extracts data groups to which a line can be fitted from the 3D point cloud data using a method such as clustering, and determines a line that represents each data group. The spatial position of the line is set as the position of the reinforcing bar.

[0140] (Step S3730) The processing device 120 projects the straight line indicating the reinforcing bar position estimated in step S3720 and the three-dimensional coordinates of the data group used to determine the straight line onto a two-dimensional plane of the image data (hereinafter referred to as an "image plane").

[0141] (Step S3740) The processing device 120 compares the straight line projected onto the image plane with the rebar area in the image to confirm that the straight line is a rebar. Based on the original 3D point cloud data, the processing device 120 compares the position of the rebar in the design drawing with the 3D coordinates of the line in 3D space to calculate the position and shape of the rebar. At this time, the processing device 120 may refine the 3D information acquired by the 3D scanner 110 based on the image information and compare the refined 3D information with the design information. Refinement can be performed, for example, by the following method: First, pixels included in the rebar area in the image, including the straight line projected onto the image plane, are identified. Next, in 3D space, the area between the multiple data points used to determine the straight line is interpolated using pixels included in the rebar area between the points projected from those data points on the image plane. This refines the outline of the rebar.

[0142] As described above, the reinforcing bar inspection system 100 of this embodiment includes a camera 170, and sets the scan range and operation of the 3D scanner 110 based on the pixel range in the image acquired by the camera 170 where reinforcing bars are estimated to exist, identified by image processing or image recognition. This allows the 3D scanner 110 to scan only the area in the structure where reinforcing bars exist. This makes it possible to quickly acquire detailed 3D position information that can provide information on the shape of the reinforcing bars, without performing measurements that require extensive scanning over a long period of time. Furthermore, by projecting the 3D point cloud data onto the plane of a 2D image, more accurate measurements of the reinforcing bar shape can be performed, enabling more precise reinforcing bar inspection.

[0143] [Modification of the third embodiment] Next, a modified example of the third embodiment will be described. The configuration of the bar arrangement inspection system 100 in this modified example is the same as the configuration shown in Fig. 15. This modified example is effective when there is parallax between the camera 170 and the 3D scanner 110.

[0144] FIG. 21 is a flowchart showing part of the operation of this modified example. In the flowchart shown in FIG. 21, the processing from step S3700 onwards in the flowchart shown in FIG. 17 is replaced with the processing from step S3700 onwards shown in FIG. 21. In this modified example, the processing from steps S1100 to S1600 shown in FIG. 17 is performed, and then the processing of step S3700 shown in FIG. 21 is executed. Step S3700 in this modified example differs from step S3700 shown in FIG. 20 in that step S3740 shown in FIG. 20 is replaced with step S4740. The operations of steps S3710 to S3730 included in step S3700 are the same as the operations of the corresponding steps shown in FIG. 20. The operations of steps S1800, S1900, and S2100 are the same as the operations of the corresponding steps shown in FIG. 10. Below, operations that differ from embodiment 3 will be described.

[0145] (Step S4740) The processing device 120 compares, on the image plane, the straight line indicating the rebar position generated from the three-dimensional position data projected onto the image plane in step S3730 with the rebar position extracted by image processing or image recognition processing on the image data, and confirms that the straight line generated from the three-dimensional position data is a rebar.

[0146] (Step S4800) The processor 120 determines whether the number of lines generated from the three-dimensional position data in step S4740 matches the number of rebars extracted from the image data. If the two numbers match, the process proceeds to step S4820. If the two numbers do not match, the process proceeds to step S4810.

[0147] (Step S4810) The processing device 120 compares the number of lines generated based on the three-dimensional position information with the number of rebars identified on the image. If the number of lines in the three-dimensional position information is greater, proceed to step S4820. If the number of rebars on the image is greater, proceed to step S4830.

[0148] (Step S4820) The processing device 120 compares the position in the three-dimensional coordinate system of the straight line projected onto the image plane with the position of the rebar in the design drawing, and generates information on the position and shape of the rebar that matches the straight line based on the three-dimensional position information.

[0149] (Step S4830) The processor 120 determines whether or not this is the first measurement of the measurement range. If two or more measurements have been made for the measurement range, the process proceeds to step S2100. If this is the first measurement, the process proceeds to step S4900.

[0150] (Step S4900) The processing device 120 performs processing to change the measurement position of the 3D scanner 110. In step S1800, if the number of rebars is less than the number in the design drawing, and the direction of the fewer rebars is parallel to the x-axis, the measurement position is changed to the y-axis direction. If the direction of the fewer rebars is parallel to the y-axis, the measurement position is changed to the x-axis direction. As described above, the change of the measurement position may be manual or automatic. The processing device 120 may generate a signal requesting the user to change the position of the 3D scanner 110 and perform measurements multiple times, and output the signal to a display or audio output device. After the measurement position has been changed, the process returns to step S3400, and the measurement range is remeasured.

[0151] When the camera 170 and the 3D scanner 110 are used in combination, parallax often occurs between the camera 170 and the 3D scanner 110 due to differences in the shooting direction of the camera 170 and the measurement direction of the 3D scanner 110. When parallax exists between the camera 170 and the 3D scanner 110, the measurement angle or position at which occlusion occurs with the camera 170 differs from the measurement angle or position at which occlusion occurs with the 3D scanner 110. In step S4900 in FIG. 21 , the measurement angle or position may be changed, for example, so that the spacing between rebars recognized from the camera image increases by the thickness of one rebar or more. Alternatively, the amount of movement or rotation angle corresponding to the measured thickness of the rebar may be calculated geometrically based on the number of pixels in the thickness direction of the rebar extracted from the image or information about the rebar thickness included in the design information, and the distance from the 3D scanner 110 to the measured rebar or a nearby rebar. In this way, the processing device 120 may determine the amount of movement or rotation angle of the position of the 3D scanner 110 based on the thickness of the rebar described in the design information or the thickness of the rebar obtained based on image recognition, and the measured three-dimensional information.

[0152] Note that there may be cases where the shooting direction of the camera 170 and the measurement direction of the 3D scanner 110 are the same, i.e., the optical axes of the camera 170 and the 3D scanner 110 are coaxial and there is no parallax. In this case, the occlusions occurring in the camera 170 and the 3D scanner 110 are the same, and the positions at which the occlusions occur are the same. In this case, in the above step S4800, the number of straight lines based on the three-dimensional position information and the number of rebars on the image always match, and the process always proceeds to step S4810. If the number of rebars extracted due to occlusion differs from the number of rebars shown in the design drawing, the process proceeds from step S1800 to step S4830, and then to step S4900. If the optical axes of the camera 170 and the 3D scanner 110 are coaxial, in step S4900, the angle or position of the 3D scanner 110 and the camera 170 may be changed while checking the number of rebars in the image captured by the camera 170, and the 3D scanner 110 and the camera 170 may be installed at the angle or position when a change occurs in the number of rebars in the image (for example, an increase in the number). In this way, occlusion can be avoided and re-measurement can be performed. Alternatively, if there is no parallax between the camera 170 and the 3D scanner 110, 3D measurement without occlusion may be performed using the operation shown in FIG. 22.

[0153] Fig. 22 is a flowchart showing the operation of another modified example of the third embodiment, which is effective when there is no parallax between the camera 170 and the 3D scanner 110. The operation shown in Fig. 22 is the same as the operation shown in Fig. 17 except that steps S4850 and S4900 are added after step S3400. In steps S4850 and S4900, the following processes are performed.

[0154] (Step S4850) The number of rebars recognized from the image acquired by camera 170 is counted, and it is determined whether this number matches the number of rebars shown on the design drawing. If the number of recognized rebars matches the number of rebars shown on the design drawing, the process proceeds to step S3500. If the numbers do not match, the process proceeds to step S4900.

[0155] (Step S4900) As in step S4900 shown in FIG. 21, the positions or angles of the 3D scanner 110 and the camera 170 are changed.

[0156] By repeating steps S3400, S4850, and S4900, the 3D scanner 110 and camera 170 can be placed at a measurement position or angle where occlusion does not occur, enabling accurate reinforcement inspection. A limit may be placed on the number of repetitions of steps S3400, S4850, and S4900. If the number of rebars on the design drawing and the number of rebars recognized in the image do not match even after the position or angle has been changed a sufficient number of times to avoid occlusion, the process may proceed to step S2100.

[0157] This operation allows the 3D scanner 110 and camera 170 to move with minimal movement, generating accurate 3D position data without occlusion loss with a small number of measurements. This allows the shape and position of rebar to be measured efficiently, enabling highly accurate bar arrangement inspection in a short time.

[0158] As described above, in the third embodiment and its modifications, by projecting three-dimensional position information onto an image, it is possible to generate shape information with higher resolution than the shape information (e.g., thickness) of the reinforcing bars based on the three-dimensional measurement results by the 3D scanner 110. This allows for more detailed inspection of the reinforcing bar arrangement.

[0159] In the third embodiment and its modified examples, the scan range of the 3D scanner 110 is determined based on the image acquired by the camera 170. In the acquired image, there may be cases where the image of the rebar is missing due to an obstacle ahead, resulting in the scan range being divided or an insufficient scan range being set. To solve this problem, in step S3500, a line is fitted to the edge extracted in step S3400 or the rebar area obtained by image recognition. If the fitted line coincides with multiple rebar areas, the rebar areas may be considered to be the same rebar and a scan plan may be set for all of the rebar areas. In this case, a detailed scan may be performed on the rebar areas, and measurement points may not be set in areas other than the rebar areas, or the spatial frequency of measurement points may be set to be low.

[0160] When comparing the data with the design drawings in step S3700, the rebars may be identified and processed in units of the scan range. For areas where there are no data points due to occlusion, the positions of the rebars may be estimated by linear interpolation. That is, the processing device 120 may generate interpolated 3D information in which blind spots due to occlusion are interpolated by linearly interpolating the 3D position coordinates of multiple measurement points included in the 3D information, and update the interpolated 3D information as 3D information for comparison.

[0161] The processing device 120 may generate 3D information for verification by integrating measurement results obtained by changing the position of the 3D scanner 110 and performing measurements multiple times. For example, when rebars are arranged horizontally, the processing device 120 may generate 3D information for verification by integrating measurement results obtained by changing the position of the 3D scanner 110 vertically and performing measurements multiple times. Furthermore, when rebars are arranged vertically, the processing device 120 may generate 3D information for verification by integrating measurement results obtained by changing the position of the 3D scanner horizontally and performing measurements multiple times. When the number of rebars obtained based on the 3D information is less than the number of rebars obtained by image recognition based on image information of the structure acquired by the camera 170 or the number of rebars described in the design information, the processing device 120 may generate a signal requesting that the position of the 3D scanner 110 be changed and measurements performed multiple times.

[0162] [Note] The above description of the embodiments discloses the following techniques.

[0163] (Technology 1) A 3D scanner that acquires 3D information about structures, including rebar, and a processing device that acquires preliminary data on the placement of the reinforcing bars and design information of the reinforcing bars, sets the measurement operation of the 3D scanner based on the preliminary data, and compares the 3D information acquired by the 3D scanner through the measurement operation based on the settings with the design information; an output device that outputs the result of the reinforcing bar arrangement inspection based on the result of the comparison; A reinforcement inspection system equipped with

[0164] (Technology 2) 2. The reinforcement arrangement inspection system according to claim 1, wherein the preliminary data includes preliminary three-dimensional information acquired by the three-dimensional scanner before setting of the measurement operation.

[0165] (Technology 3) 3. The reinforcement arrangement inspection system according to claim 2, wherein a spatial density of measurement points in the preliminary three-dimensional information is lower than a spatial density of measurement points in the three-dimensional information acquired by the measurement operation based on the settings.

[0166] (Technology 4) 3. The reinforcing bar arrangement inspection system according to claim 2, wherein the intervals between the measurement points in the preliminary three-dimensional information are narrower than the intervals between the reinforcing bars indicated in the design information.

[0167] (Technology 5) 2. The reinforcement arrangement inspection system according to claim 1, wherein the preliminary data is generated based on the design information.

[0168] (Technology 6) Further provided with a GNSS unit for acquiring location information by GNSS, The design information includes information on GNSS coordinates of the reinforcing bars, the processing device determines the position and orientation of the 3D scanner based on the position information acquired by the GNSS unit and the GNSS coordinates included in the design information; The reinforcement inspection system according to claim 1.

[0169] (Technology 7) 7. The bar arrangement inspection system according to claim 6, wherein the preliminary data is generated based on the position information acquired by the GNSS unit and the GNSS coordinates included in the design information.

[0170] (Technology 8) It also has a camera, the preliminary data is generated based on image information of the structure acquired by the camera; The reinforcement inspection system according to claim 1.

[0171] (Technology 9) 9. The reinforcement bar arrangement inspection system according to claim 8, wherein the processing device increases the resolution of the three-dimensional information acquired by the three-dimensional scanner based on the image information, and compares the increased resolution three-dimensional information with the design information.

[0172] (Technology 10) 2. The reinforcement bar arrangement inspection system according to claim 1, wherein the processing device calculates a probability or likelihood of the presence of the reinforcing bar based on the preliminary data, and sets the measurement operation based on the probability or likelihood of the presence.

[0173] (Technology 11) the preliminary data includes preliminary three-dimensional information acquired by the three-dimensional scanner prior to setting up the measurement operation; The processing device calculates the existence probability or the likelihood of the reinforcing bar based on the preliminary three-dimensional information. The reinforcement inspection system according to claim 10.

[0174] (Technology 12) 11. The reinforcement bar arrangement inspection system according to claim 10, wherein the processing device calculates the existence probability or the likelihood of the reinforcing bar based on the design information.

[0175] (Technology 13) 11. The reinforcement bar arrangement inspection system according to claim 10, wherein the processing device corrects the existence probability or likelihood of the reinforcing bar according to a thickness of the reinforcing bar.

[0176] (Technology 14) 2. The reinforcement inspection system according to claim 1, wherein the processing device generates the three-dimensional information by integrating measurement results obtained by performing measurements multiple times while changing the position of the three-dimensional scanner.

[0177] (Technology 15) 2. The reinforcing bar inspection system according to claim 1, wherein the processing device generates the three-dimensional information by integrating measurement results obtained by changing the position of the three-dimensional scanner in the vertical direction and taking measurements multiple times when the reinforcing bars are arranged horizontally.

[0178] (Technology 16) 2. The reinforcing bar inspection system according to claim 1, wherein the processing device generates the three-dimensional information by integrating the measurement results obtained by changing the position of the three-dimensional scanner in the horizontal direction and taking measurements multiple times when the reinforcing bars are arranged vertically.

[0179] (Technology 17) The reinforcing bar inspection system of claim 1, wherein the processing device generates a signal requesting that the position of the 3D scanner be changed and measurements be taken multiple times when the number of reinforcing bars obtained based on the 3D information is less than the number of reinforcing bars obtained by image recognition based on image information of the structure acquired by a camera or the number of reinforcing bars described in the design information.

[0180] (Technology 18) 18. The reinforcement bar inspection system according to claim 17, wherein the processing device determines the amount of movement of the position of the 3D scanner based on the thickness of the reinforcing bar described in the design information or the thickness of the reinforcing bar obtained based on the image recognition, and the measured 3D information.

[0181] (Technology 19) 2. The reinforcement inspection system according to claim 1, wherein the processing device generates interpolated 3D information in which blind spots due to occlusion are interpolated by linearly interpolating 3D position coordinates of a plurality of measurement points included in the 3D information, and updates the interpolated 3D information as the 3D information.

[0182] (Technology 20) 2. The reinforcement inspection system according to claim 1, wherein the three-dimensional scanner includes an FMCW LiDAR sensor.

[0183] (Technology 21) A method for inspecting reinforcement of a structure including reinforcing bars, comprising: obtaining preliminary data regarding placement of rebar and design information for said rebar; setting the measurement operation of the 3D scanner based on the preliminary data; comparing the three-dimensional information acquired by the three-dimensional scanner through a measurement operation based on the settings with the design information; outputting a reinforcement inspection result based on the result of the comparison; and A method comprising: [Industrial Applicability]

[0184] The technology of the present disclosure can be widely used for reinforcement inspection. For example, the technology of the present disclosure can be used in an apparatus or system that performs reinforcement inspection using a measuring device such as a 3D scanner that acquires three-dimensional point cloud data. [Explanation of symbols]

[0185] 100 Reinforcement Inspection System 110 3D scanner 120 Processing equipment 130, 114 Storage device 140 Input Device 150 Output Device 111 LiDAR sensors 112 Optical deflector 113 Control circuit 115 Attitude Sensor 160 GNSS units 170 Camera

Claims

1. a 3D scanner for acquiring 3D information of a structure including rebar; a processing device that acquires preliminary data regarding the placement of the reinforcing bars and design information of the reinforcing bars, sets the measurement operation of the 3D scanner based on the preliminary data, and compares the 3D information acquired by the 3D scanner through the measurement operation based on the settings with the design information; an output device that outputs the result of the reinforcing bar arrangement inspection based on the result of the comparison; A reinforcement inspection system equipped with

2. The reinforcement bar arrangement inspection system according to claim 1 , wherein the preliminary data includes preliminary three-dimensional information acquired by the three-dimensional scanner before setting of the measurement operation.

3. The reinforcement bar arrangement inspection system according to claim 2 , wherein a spatial density of the measurement points in the preliminary three-dimensional information is lower than a spatial density of the measurement points in the three-dimensional information acquired by the measurement operation based on the settings.

4. The reinforcing bar arrangement inspection system according to claim 2 , wherein the intervals between the measurement points in the preliminary three-dimensional information are narrower than the intervals between the reinforcing bars indicated in the design information.

5. The reinforcement bar arrangement inspection system according to claim 1 , wherein the preliminary data is generated based on the design information.

6. Further provided is a GNSS unit that acquires location information by GNSS, The design information includes information on GNSS coordinates of the reinforcing bars, the processing device determines the position and orientation of the three-dimensional scanner based on the position information acquired by the GNSS unit and the GNSS coordinates included in the design information; The reinforcement inspection system according to claim 1 .

7. The bar arrangement inspection system according to claim 6 , wherein the preliminary data is generated based on the position information acquired by the GNSS unit and the GNSS coordinates included in the design information.

8. It also has a camera, the preliminary data is generated based on image information of the structure acquired by the camera; The reinforcement inspection system according to claim 1 .

9. 9. The reinforcement inspection system according to claim 8, wherein the processing device increases the resolution of the three-dimensional information acquired by the three-dimensional scanner based on the image information, and compares the increased resolution three-dimensional information with the design information.

10. The reinforcement bar arrangement inspection system according to claim 1 , wherein the processing device calculates a probability or likelihood of the presence of the reinforcing bar based on the preliminary data, and sets the measurement operation based on the probability or likelihood of the presence.

11. the preliminary data includes preliminary three-dimensional information acquired by the three-dimensional scanner prior to setting up the measurement operation; The processing device calculates the existence probability or the likelihood of the reinforcing bar based on the preliminary three-dimensional information. The reinforcement inspection system according to claim 10.

12. The reinforcement bar arrangement inspection system according to claim 10 , wherein the processing device calculates the existence probability or the likelihood of the reinforcing bar based on the design information.

13. The reinforcement bar arrangement inspection system according to claim 10 , wherein the processing device corrects the existence probability or likelihood of the reinforcing bar according to a thickness of the reinforcing bar.

14. The reinforcement bar arrangement inspection system according to claim 1 , wherein the processing device generates the three-dimensional information by integrating measurement results obtained by performing measurements a plurality of times while changing the position of the three-dimensional scanner.

15. 2. The reinforcing bar inspection system according to claim 1, wherein the processing device generates the three-dimensional information by integrating measurement results obtained by changing the position of the three-dimensional scanner in the vertical direction and taking measurements multiple times when the reinforcing bars are arranged horizontally.

16. 2. The reinforcing bar inspection system according to claim 1, wherein the processing device generates the three-dimensional information by integrating the measurement results obtained by changing the position of the three-dimensional scanner in the horizontal direction and taking measurements multiple times when the reinforcing bars are arranged vertically.

17. 2. The reinforcement bar inspection system according to claim 1, wherein the processing device generates a signal requesting that the position of the three-dimensional scanner be changed and measurements be taken multiple times when the number of reinforcing bars obtained based on the three-dimensional information is less than the number of reinforcing bars obtained by image recognition based on image information of the structure acquired by a camera or the number of reinforcing bars described in the design information.

18. The reinforcing bar inspection system according to claim 17, wherein the processing device determines the amount of movement of the position of the three-dimensional scanner based on the thickness of the reinforcing bar described in the design information or the thickness of the reinforcing bar obtained based on the image recognition, and the measured three-dimensional information.

19. 2. The reinforcement inspection system according to claim 1, wherein the processing device generates interpolated three-dimensional information in which blind spots due to occlusion are interpolated by linearly interpolating three-dimensional position coordinates of a plurality of measurement points included in the three-dimensional information, and updates the interpolated three-dimensional information as the three-dimensional information.

20. The reinforcing bar inspection system according to claim 1 , wherein the three-dimensional scanner includes an FMCW type LiDAR sensor.

21. A method for inspecting reinforcement of a structure including reinforcing bars, comprising: obtaining preliminary data regarding placement of rebar and design information for said rebar; setting a measurement operation of a three-dimensional scanner based on the preliminary data; comparing the three-dimensional information acquired by the three-dimensional scanner through a measurement operation based on the settings with the design information; outputting a reinforcement inspection result based on the result of the comparison; and A method comprising:

Images