JP2022143470A - Survey system, survey apparatus, survey method, and survey program - Google Patents

Abstract

To provide a survey system, an apparatus, a method, and a program, which are excellent in workability with low risk.SOLUTION: The survey system uses a laser scanner 200 to perform laser scanning of an area including a boundary 130 between an upper surface 110 and a side surface 120 of a structure 100 and acquire ground side point group data, uses a camera 310 provided in an unmanned aerial vehicle 300 to acquire image data for the area including the boundary 130 and the upper surface 110, calculates flight side point group data from the image data, and superimposes the flight side point group data on the ground side point group data on the basis of the flight side point group data and the ground side point group data in the boundary 130.SELECTED DRAWING: Figure 1

Description

The present invention relates to a technique for surveying structures such as bridge piers.

Conventionally, a method using a total station or a laser scanner is generally used as a method of surveying a structure. In these surveying methods, measurements are performed by installing a total station or the like at a place where the measurement points can be visually observed. However, conventional surveying methods may require a large amount of work or may be dangerous, depending on the construction location and size of the structure. For example, consider a bridge consisting of a superstructure and a substructure as a structure. In the conventional surveying of substructures before the start of superstructure construction, aerial work vehicles are installed and surveys are performed by climbing onto bridge piers. It was necessary to use a boarding crane on the leg.

JP-A-8-285588

As a method for solving such a problem, there is a photogrammetry technology in which a camera is provided in an unmanned aerial vehicle called a drone and surveying is performed based on image data captured by the camera (see Patent Document 1). However, the current photogrammetry technology has a measurement error of the order of centimeters, and is not sufficient for use in surveying that requires accuracy on the order of millimeters.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a surveying system, apparatus, method, and program with good workability and low risk.

In order to achieve the above object, the present invention provides a surveying system for surveying the upper surface of a structure, wherein the area including the boundary between the upper surface and the side surface of the structure is located on the side surface side and below the upper surface. and a laser scanner for obtaining first point cloud data by laser scanning from the upper surface of the structure, and a boundary portion between the upper surface and the side surface of the structure, and an area including the upper surface. An unmanned aerial vehicle equipped with a camera, a boundary between the upper surface and the side surface of the structure calculated from the image data, and second point cloud data in an area including the upper surface, the first point cloud data at the boundary and and superimposing means for superimposing the second point cloud data on the first point cloud data.

Further, the present invention is a surveying method for surveying the upper surface of a structure, wherein a laser scanner is used to measure a region including a boundary between the upper surface and the side surface of the structure from the side surface side and below the upper surface. acquiring first point cloud data by laser scanning; and capturing an image of a boundary between a top surface and a side surface of the structure and an area including the top surface from the air above the top surface using a camera provided on an unmanned aerial vehicle. obtaining image data from the image data; calculating second point cloud data in an area including the boundary between the top surface and the side surface of the structure and the top surface from the image data; is superimposed on the first point cloud data based on the first point cloud data and the second point cloud data at the boundary.

Further, the present invention is a surveying device for surveying the upper surface of a structure, wherein first point cloud data acquired by a laser scanner installed below the upper surface of the structure and points above the upper surface of the structure Point cloud data acquisition means for acquiring second point cloud data calculated based on image data captured by a camera provided on an unmanned aerial vehicle flying in the air; superimposition means for superimposing on point cloud data, wherein the first point cloud data is obtained by laser scanning an area including the boundary between the upper surface and the side surface of the structure, and the second point cloud data is obtained. The data is calculated from the image data captured for the boundary between the upper surface and the side surface of the structure and the area including the upper surface. The first point cloud data and the second point cloud data are superimposed on the first point cloud data.

According to the present invention, the second point cloud data with a relatively large error calculated from the image data captured by the camera of the unmanned aerial vehicle is converted to the first point cloud data with a relatively small error acquired by the laser scanner. Since they are superimposed, it is possible to reduce the measurement error even on the upper surface of the structure that cannot be directly observed from the laser scanner. Therefore, there is no need to perform dangerous and time-consuming high-place work to measure the upper surface of the structure, and workability is improved.

Configuration diagram of a surveying system according to the first embodiment Functional block diagram of the surveying instrument according to the first embodiment Surveying procedure using the surveying system according to the first embodiment Configuration diagram of a surveying system according to the second embodiment Functional block diagram of a surveying instrument according to the second embodiment

(First embodiment)
A surveying system according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a surveying system, and FIG. 2 is a functional block diagram of a surveying device.

In this embodiment, a substructure of a bridge (also referred to as a substructure or frame) is exemplified as a structure to be surveyed. Further, in this embodiment, after the substructure is completed and before the construction of the superstructure is started, the position of one or more bearings provided on the upper surface of the completed substructure is measured, and the adjacent substructure is measured. A case of measuring the distance between corresponding bearings provided on the work surface will be described. It should be noted that the distance between adjacent substructures is on the order of 10 to 100 meters, whereas the tolerances for bearing positions and distances between bearings are on the order of millimeters.

As shown in FIG. 1, the surveying system according to the present embodiment includes a laser scanner 200 that scans each of the plurality of substructures 100 with a laser beam to obtain point cloud data, and an aerial image of each of the plurality of substructures 100. An unmanned aerial vehicle 300 equipped with a camera 310 that acquires image data using a laser scanner 200 and a surveying device 400 that performs surveying based on data acquired from the laser scanner 200 and the camera 310 . The acquisition of point cloud data by the laser scanner 200 and the acquisition of image data by the unmanned aerial vehicle 300 are performed for each substructure 100 by changing the installation position of the laser scanner 200 and the flight position of the unmanned aerial vehicle 300 .

Each substructure 100 has a horizontal upper surface 110 and a vertical direction orthogonal to the side surface 120 . A bearing 111 to be surveyed is formed on the upper surface 110 . A boundary portion 130 between the top surface 110 and the side surface 120 is formed with a C surface 131 by chamfering a corner portion where the top surface 110 and the side surface 120 intersect.

The laser scanner 200 irradiates a laser beam and receives reflected light reflected by an object, and measures the distance to the object based on the time from irradiation to light reception and the phase of the reflected light. The laser scanner 200 scans a space with a laser beam, measures the distance to each point of an object in the space, and generates point cloud data that is a set of three-dimensional spatial coordinates of each point.

The laser scanner 200 is installed below an upper surface 110 on which a bearing 111 to be surveyed is formed. In other words, the laser scanner 200 cannot observe the top surface 110 including the bearings 111, and the laser scanner 200 cannot generate point cloud data for the top surface 110 including the bearings 111.

In the present invention, the laser scanner 200 is installed on the ground at a predetermined distance from the side surface 120 of the substructure 100 and performs laser scanning on an area including the boundary 130 to generate point cloud data. Assume that the installation position of the laser scanner 200 is known. The installation position of the laser scanner 200 can be acquired by measuring a known reference point with the laser scanner 200 . Also, the installation position of the laser scanner 200 can be acquired by positioning the installation position of the laser scanner 200 with another positioning device such as a total station.

The laser scanner 200 records the generated point cloud data on a predetermined recording medium. In some embodiments, the laser scanner 200 can transmit the generated point cloud data to an external device with a wired or wireless connection. The coordinates of the point cloud data recorded and transmitted by the laser scanner 200 may be relative to the installation position of the laser scanner 200, or may be absolute coordinates corrected by a known installation position. good.

The unmanned aerial vehicle 300 is a so-called drone, and flies according to a user's operation command from a remote location or based on a pre-programmed flight plan. The unmanned aerial vehicle 300 is also called a UAV (Unmanned Aerial Vehicle). The unmanned aerial vehicle 300 includes a power source such as a motor, a propeller attached to the motor, an inertial measurement device, a radio transmission/reception device, a power supply, the camera 310 for surveying, and a control device for controlling each part. The inertial measurement device is used to measure and control the behavior and current position of the unmanned aerial vehicle 300 . The inertial measurement device can include various sensors such as a 3-axis acceleration sensor, a 3-axis angular velocity sensor, an air pressure sensor, an ultrasonic sensor, a magnetic orientation sensor, and a GNSS (Global Navigation Satellite System) receiver.

The camera 310 captures still images or moving images to generate image data. Camera 310 records image data on a predetermined recording medium. In some embodiments, camera 310 can transmit image data in real time or in batches after capture to external wired or wirelessly connected devices. The image data includes shooting conditions such as position information at the time of shooting as metadata. The position information at the time of shooting can be obtained from the inertial measurement device of the unmanned aerial vehicle 300 . The camera 310 can control the imaging conditions such as the angle of view and the imaging direction from the control device of the unmanned aerial vehicle 300 . Camera 310 is fixed to unmanned aerial vehicle 300 . In some embodiments, camera 310 includes a drive to change its orientation relative to unmanned aerial vehicle 300 . In some embodiments, camera 310 includes shock absorbers to prevent blurring of image data due to vibrations.

In the present invention, unmanned aerial vehicle 300 is flown remotely or based on a flight plan such that camera 310 images an area including boundary 130 and top surface 110 of substructure 100 . Here, the upper surface 110, which is part of the object to be photographed, does not need to be the entire area of the upper surface 110, and may be an area including the bearing 111 to be surveyed. Also, the side surface 120 of the substructure 100 may be included in the imaging area. In order for camera 310 to be able to image such areas, unmanned aerial vehicle 300 flies at least above upper surface 110 of substructure 100 . In the present embodiment, since an image of at least an area adjacent to the boundary portion 130 of the side surface 120 of the substructure 100 is also imaged, the unmanned aerial vehicle 300 detects the side surface 120 of the side surface 120 on which the laser scan 200 is installed with respect to the upper surface 110 of the substructure 100. Fly diagonally above the side. The camera 310 acquires at least two pieces of image data with different imaging positions so that point cloud data can be generated from the image data as described later. The camera 310 can acquire a plurality of image data by capturing moving images at a predetermined frame rate while moving the unmanned aerial vehicle 300 .

As shown in FIG. 2, the surveying apparatus 400 includes a point cloud data conversion processing unit 410, a point cloud data acquisition unit 420, a superimposition processing unit 430, a measurement point search unit 440, a survey calculation unit 450, and a storage unit. 460. Each part of the surveying instrument 400 is configured by installing a program in a computer having a main computing device, a main storage device, an auxiliary storage device, a display device, an input device, and the like. In some embodiments, surveying instrument 400 comprises dedicated hardware. In some embodiments, the surveying device 400 is distributed across multiple devices. In some embodiments, surveying instrument 400 is implemented on a cloud server.

A point cloud data conversion processing unit 410 converts a plurality of image data acquired from the camera 310 into point cloud data. Various algorithms used in photogrammetry can be used for converting image data into point cloud data. In the following description, the point cloud data generated by the laser scanner 200 will be referred to as ground side point cloud data, and the point cloud data generated by the point cloud data conversion processing unit 410 will be referred to as aerial side point cloud data.

In this embodiment, the camera 310 generates moving image data including position information as image data, and the point cloud data conversion processing unit 410 generates aerial point cloud data, which is a set of three-dimensional spatial coordinates, from this moving image data. . Also, the point cloud data conversion processing unit 410 acquires moving image data from the camera 310 via a predetermined storage medium. Position information included in the image data is measured by the inertial measurement device of the unmanned aerial vehicle 300 . Therefore, it should be noted that the errors in the coordinates of the aerial point cloud data are usually on the order of centimeters and do not meet the bearing position tolerances, which are on the order of millimeters.

The point cloud data acquisition unit 420 acquires the ground side point cloud data and the air side point cloud data, and stores them in the storage unit 460 . In the present embodiment, the point cloud data acquisition unit 420 acquires ground side point cloud data from the laser scanner 200 via a predetermined storage medium, and also acquires aerial side point cloud data from the point cloud data conversion processing unit 410. do.

The superimposition processing unit 430 superimposes the ground-side point cloud data and the air-side point cloud data stored in the storage unit 460 to generate superimposed point cloud data, and stores the superimposed point cloud data in the storage unit 460. . That is, the air-side point cloud data is superimposed on the ground-side point cloud data based on the ground-side point cloud data and the air-side point cloud data in the boundary portion 130 . In other words, the superimposition processing unit 430 performs coordinate transformation so that the coordinate system of the point cloud data on the air side, which has a relatively large error, matches the coordinate system of the point cloud data on the ground side, which has a relatively small error. The side point cloud data and the ground side point cloud data are combined into one superimposed point cloud data. Furthermore, in other words, the superimposition processing unit 430 can be considered to correct the air-side point cloud data using the ground-side point cloud data.

Here, the superimposing process is based on the data in the boundary portion 130, which is the superimposed area of the ground-side point cloud data and the air-side point cloud data. That is, the coordinate transformation is performed so that the air-side point cloud data at the boundary 130 is matched with the ground-side point cloud data at the boundary 130 . More specifically, the coordinates of the feature points in the boundary portion 130 of the substructure 100 included in the aerial-side point cloud data in the boundary portion 130 are changed to the coordinates of the feature points included in the ground-side point cloud data in the boundary portion 130. Perform coordinate transformation to match. For this reason, the superimposition processing unit 430 has a feature point extraction function unit that extracts feature points in the boundary portion 130 from each point cloud data. In the present embodiment, a ridge line, which is a boundary line between boundary portion 130 and side surface 120, is extracted as a feature point. In addition, the said ridgeline is also called a pier crest profile line or a C surface lower profile line.

The measurement point search unit 440 searches for point cloud data related to the survey target from the superimposed point cloud data, calculates the position (coordinate data) of the survey target as a survey result, and stores the result in the storage unit 460 . Specifically, the measurement point search unit 440 extracts feature points related to the survey object from the superimposed point cloud data, calculates the positions (coordinate data) of these feature points as survey results, and stores them in the storage unit 460 . In the present embodiment, measurement point searching section 440 calculates the position (coordinate data) of bearing 111 provided on upper surface 110 of substructure 100 .

The above-described processing by the superimposition processing unit 430 and the measurement point searching unit 440 is performed for each acquired ground-side point cloud data. In the present embodiment, the position (coordinate data) of one or more bearings 111 provided on the upper surface 110 of the substructure 100 for each ground side point cloud data acquired by the laser scanner 200 for each of the substructures 100 Calculate

The survey calculation unit 450 calculates the distance between arbitrary survey objects from the positions (coordinate data) of the plurality of survey objects surveyed by the measurement point search unit 440 . In this embodiment, the distance between the corresponding bearings 111 provided on the upper surfaces 110 of the adjacent substructures 100 is calculated, output as a survey result, and stored in the storage unit 460 .

A surveying procedure according to the present embodiment will be described with reference to the flowchart of FIG. First, the laser scanner 200 is used to scan a region including the boundary portion 130 from the side surface 120 side and below the upper surface 110 to acquire ground side point cloud data (step S1).

Further, the camera 310 provided on the unmanned aerial vehicle 300 is used to image an area including the boundary portion 130 and the upper surface 110 from the air above the upper surface 110 to obtain image data (step S2-1). Next, from the image data, aerial side point cloud data in the area including the boundary portion 130 and the upper surface 110 is generated (step S2-2).

The above steps S1 to S2-2 are performed for each structure to be surveyed. In this embodiment, each of the plurality of substructures 100 is subjected to this.

Next, the surveying instrument 400 superimposes the flight-side point cloud data on the ground-side point cloud data based on the ground-side point cloud data and the flight-side point cloud data at the boundary 130 to generate superimposed point cloud data ( step S3). Next, the surveying device 400 calculates the positions (coordinate data) of the measurement points from the superimposed point cloud data (step S4). Finally, the surveying device 400 calculates the distance between arbitrary surveying points (step S5). In this embodiment, the distance between the corresponding bearings 111 provided on the upper surfaces 110 of the adjacent substructures 100 is calculated.

The acquisition of the image data in step S2-1 may be performed prior to the acquisition of the ground-side point cloud data in step S1.

According to such a survey system, since the aerial point cloud data with relatively large errors is superimposed on the ground side point cloud data with relatively small errors, the substructure 100 cannot be directly observed from the laser scanner 200. It is possible to reduce the surveying error even with the upper surface 110 of . Therefore, there is no need to perform dangerous and time-consuming high-place work for measuring the upper surface of the substructure 100, and workability is improved.

(Second embodiment)
A surveying system according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a configuration diagram of the surveying system, and FIG. 5 is a functional block diagram of the surveying device.

The surveying system according to the present embodiment differs from the first embodiment in that, as shown in FIG. be. Since other configurations are the same as those of the first embodiment, only the points of difference will be described here.

The positioning device 500 measures the position (coordinates) of a predetermined reference point included in the scan area of the substructure 100 by the laser scanner 200 by laser positioning. A total station is used as the positioning device 500 in this embodiment. Assume that the installation position of the positioning device 500 is known. The installation position of the positioning device 500 can be obtained by positioning another known reference point with the positioning device 500 . The predetermined reference point can be any point on the boundary 130 . Also, the predetermined reference point can be any point other than the boundary portion 130 . A measurement result obtained by the positioning device 500 is provided to the surveying device 400 . Also, the predetermined reference point may be a component of the substructure 100 or may be set on the substructure 100 for surveying. In this embodiment, one of the corners of the substructure 100 is used as the reference point.

The surveying device 400 includes a reference point position acquisition unit 470 that acquires the reference point positions measured by the positioning device 500 and stores them in the storage unit 460, as shown in FIG. The acquisition method of the reference point position is irrelevant. For example, it may be acquired via a predetermined storage medium. Alternatively, the positioning device 500 and the surveying device 400 may be wired or wirelessly connected to transmit and receive the reference point position. Alternatively, the reference point position may be input to the measuring device 400 manually.

The superimposition processing unit 430 has a function of correcting ground-side point cloud data or superimposed point cloud data using the reference point positions. Therefore, the superimposition processing unit 430 has a function of extracting predetermined reference points as feature points from the ground-side point cloud data or the superimposed point cloud data.

According to such a surveying system, as in the first embodiment, the aerial point cloud data with relatively large errors is superimposed on the ground side point cloud data with relatively small errors. Even the top surface 110 of the substructure 100 that cannot be directly observed from the laser scanner 200 can reduce the measurement error. By the way, in order to further improve the accuracy in the configuration of the first embodiment, it is necessary to use a more expensive laser scanner 200 . On the other hand, in the present embodiment, since the positioning device 500, which is generally cheaper than the laser scanner 200, is used for correction, it is possible to improve the accuracy at low cost. Other functions and effects are the same as those of the first embodiment.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various improvements and modifications may be made without departing from the gist of the present invention. .

For example, in the above embodiment, the surveying instrument 400 is provided with the point cloud data conversion processing unit 410 that calculates the aerial point cloud data from the image data captured by the camera 310, but this processing unit is implemented in another computer. , or may be mounted on the unmanned aerial vehicle 300 .

Also, in the above embodiment, the substructure of a bridge was described as a structure to be surveyed, but the present invention can be applied to other structures as well.

DESCRIPTION OF SYMBOLS 100... Structure 110... Upper surface 120... Side surface 130... Boundary part 200... Laser scanner 300... Unmanned aerial vehicle 310... Camera 400... Surveying device 410... Point cloud data conversion processing part 420... Point cloud data acquisition part 430... Superimposition processing part 440 ... measurement point search unit 450 ... survey calculation unit 450
460... Storage unit 470... Reference point position acquisition unit

Claims (6)

A surveying system for surveying the upper surface of a structure,
a laser scanner that acquires first point cloud data by laser-scanning an area including a boundary between an upper surface and a side surface of the structure from the side surface side and below the upper surface;
an unmanned aerial vehicle equipped with a camera that acquires image data by capturing an image of an area including a boundary between a top surface and a side surface of the structure and the top surface from the air above the top surface;
Second point cloud data in an area including the boundary between the upper surface and the side surface of the structure calculated from the image data and the upper surface based on the first point cloud data and the second point cloud data in the boundary and superimposing means for superimposing the first point cloud data on the first point cloud data. A positioning device that performs laser positioning of a predetermined reference point of the structure,
2. The surveying system according to claim 1, wherein said superimposing means corrects at least the first point cloud data based on the positional information of the reference points positioned by said positioning device. 3. The surveying system according to claim 1, wherein the camera captures an image from the air obliquely above the side surface of the upper surface of the structure so that the side surface of the structure is reflected. A surveying method for surveying the upper surface of a structure,
obtaining first point cloud data by using a laser scanner to scan a region including the boundary between the upper surface and the side surface of the structure from the side surface side and below the upper surface;
a step of capturing image data from the air above the upper surface of a boundary between the upper surface and the side surface of the structure and an area including the upper surface using a camera provided on the unmanned aerial vehicle;
a step of calculating second point cloud data in an area including a boundary between a top surface and a side surface of the structure and the top surface from the image data;
and superimposing the second point cloud data on the first point cloud data based on the first point cloud data and the second point cloud data at the boundary. Method. A surveying device for surveying the upper surface of a structure,
Based on first point cloud data acquired by a laser scanner installed below the upper surface of the structure and image data captured by a camera mounted on an unmanned aircraft flying in the air above the upper surface of the structure Point cloud data acquisition means for acquiring the calculated second point cloud data;
superimposing means for superimposing the second point cloud data on the first point cloud data;
The first point cloud data is obtained by laser scanning an area including the boundary between the upper surface and the side surface of the structure,
The second point cloud data is calculated from image data captured for an area including the boundary between the upper surface and the side surface of the structure and the upper surface,
The superimposition means superimposes the second point cloud data on the first point cloud data based on the first point cloud data and the second point cloud data at the boundary. Device. A surveying program that causes a computer to function as the surveying device according to claim 5 .

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