3D displacement measurement system

Abstract

To provide a displacement measurement system that can perform accurate displacement measurement by automatically and continuously performing three-dimensional planar measurement in which coordinate values are determined by combining GNSS measurement technology and technology for laser surveying by three-dimensional data measurement means, photographic surveying, and three-dimensional data measurement by a ground type 3D scanner etc., and using ground or aerial photographic measurement technology.SOLUTION: The present invention relates to a displacement measurement system that uses both GNSS measurement technology and three-dimensional data measurement technology by ground and aerial three-dimensional data measurement means, wherein the installation position of an antenna the coordinate position of which is acquired by receiving a position information signal 22 sent out from a GNSS satellite 16 is substituted for a control point 18 having position coordinates to be used for the three-dimensional data measurement, the control point 18 which is substituted for is used to generate three-dimensional data having position coordinates, and displacement of a measurement region 21 can be measured from variation of a plurality of pieces of three-dimensional data which are generated by measuring the three-dimensional data at intervals of time and have position coordinates.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a three-dimensional displacement measurement system, and particularly to a three-dimensional displacement measurement system configured by combining GNSS measurement technology with three-dimensional data measurement technologies such as laser surveying, photogrammetry, and terrestrial 3D scanner surveying obtained by three-dimensional data measurement means such as drone measurement.

Background Art

[0002] In construction work and the like, there is a risk of displacement occurring in the surrounding ground and structures due to the work, so the construction of a monitoring system for such displacement is regarded as an extremely important matter. Conventionally, for displacement measurement of the ground surface and the like, extensometers, GNSS measurement, total stations, etc. have been used. In particular, since GNSS measurement can be performed with high accuracy and in real time, it has been applied to locations where ground surface fluctuations are expected due to excavation of tunnels and the like.

[0003] However, GNSS measurement is measurement at the "point" of the ground surface position where the antenna is installed. To perform more detailed measurement over an area, it is necessary to add antennas at multiple locations, and thus there is a problem that the cost for antenna installation becomes extremely large.

[0004] On the other hand, for example, photogrammetry by a drone is known as a so-called point cloud measurement technology (area measurement technology). Such photogrammetry by a drone can perform area measurement and is utilized for measurement of the shape of earthwork.

[0005] However, since photogrammetry by a drone is a so-called relative measurement technology, to perform three-dimensional area measurement with determined coordinate values, in other words, with a determined scale, a plurality of reference points with known three-dimensional coordinate values are required. Then, to perform three-dimensional area displacement measurement by photogrammetry by a drone, continuous measurement of reference points with known coordinate values is separately required, and there is a problem that the measurement labor becomes extremely large. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2018-146546 [Patent Document 2] Japanese Patent Publication No. 2020-052029 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The present invention was devised to solve the aforementioned conventional problems, and aims to provide a displacement measurement system that can automatically and continuously perform three-dimensional surface measurements with determined coordinate values ​​using photogrammetry techniques from the ground or air, such as drones, by combining GNSS measurement technology with 3D data measurement techniques such as laser surveying, photogrammetry, and ground-based 3D scanners, thereby enabling accurate displacement measurement.

[0008] In other words, the system involves receiving positional information signals transmitted from a GNSS satellite using a GNSS antenna installed in a measurement area on the ground, and using the received positional information signals to obtain fixed coordinate values ​​for the antenna installation position. These fixed coordinate values ​​are then used as control points when performing 3D point cloud measurements, such as photogrammetry from the ground or air using drones. The objective is to provide a 3D displacement measurement system that enables accurate displacement measurement in 3D automatically and continuously while reducing the effort required to measure control points with fixed coordinate values.

[0009] Furthermore, as technologies related to achieving the above objectives, devices are known that use an aerial marker equipped with a GNSS antenna and a power battery, such as those described in Japanese Patent Publication No. 2018-146546 and Japanese Patent Publication No. 2020-052029.

[0010] Conventionally, in 3D point cloud measurements using drones and the like, position measurements were taken at each control point using surveying equipment such as a total station, thereby obtaining control points and verification points with determined coordinate values. This is because obtaining control points and verification points with determined coordinate values ​​is necessary to create 3D data in which the precise position of the measurement area is determined.

[0011] However, obtaining the coordinate values ​​of control points using surveying equipment is undeniably laborious, and the inventions described in Japanese Patent Publication No. 2018-146546 and Japanese Patent Publication No. 2020-052029 can be said to be inventions that solve the above problem.

[0012] However, the inventions described in Japanese Patent Publication No. 2018-146546 and Japanese Patent Publication No. 2020-052029 had problems, such as the fact that the installation jig for aerial markers (ground control points, verification points) could only be operated for a short time using a built-in battery, that it did not have dustproof and waterproof functions that could withstand long-term outdoor use, and that it did not have the structural durability to allow people or vehicles to pass directly above the installation jig for aerial markers.

[0013] Furthermore, in cases where measurements are performed continuously and periodically, such as displacement measurements, using drones, it was necessary to set up or remove mounting jigs for ground control points and verification points, as well as to measure their positions using measuring instruments such as total stations. The present invention solves these problems as well. [Means for solving the problem]

[0014] The present invention The system has an antenna that can receive position information signals transmitted from a GNSS satellite and acquire position coordinates. The installation location of the antenna that has acquired the position coordinates is used as a substitute for a control point with position coordinates used for 3D data measurement. Using the substitute control point, 3D data with position coordinates is measured multiple times at intervals to generate multiple 3D data sets. The displacement of the measurement area can be measured by the control unit based on the changes in the multiple generated 3D data with position coordinates. This displacement measurement system utilizes both GNSS measurement technology and 3D data measurement technology using ground and airborne 3D data measurement methods. The antenna is constructed with a roughly disc-shaped antenna body and a fixing rod-shaped part that is connected to and hangs down from approximately the center of the bottom of the antenna body. It is housed in a location excavated in the ground, with the antenna body extending horizontally and positioned below the ground surface. A cover is attached directly above the antenna body, which closes the upper opening of the excavation and is made of a material that allows the antenna to receive position information signals from GNSS satellites. Measurement markers for control points used in the three-dimensional data measurement are provided on the surface of the cover. It is characterized by the following: or The aforementioned means for measuring 3D data from the ground and air is 3D data measurement from the ground and air using a drone. It is characterized by the following: or A measurement mark pattern is painted on the surface of the lid to form a measurement mark, and this measurement mark serves as a marker for acquiring a control point having the aforementioned position coordinates. characterized in that or The aforementioned cover was installed so as to be approximately flush with the ground surface. It is characterized by the following: or The three-dimensional data to be measured is three-dimensional point cloud data. characterized in that or The antenna is fixed and mounted within a container-shaped ground point forming member housed in the excavation site. It is characterized by the following: or The aforementioned antenna is installed inside a ground control point forming member at an excavation site excavated in an area where vehicles and people pass by. It is characterized by the following: or A moisture-absorbing material for antenna protection is attached to a container-shaped ground point forming member housed in the aforementioned excavation site. Characterized by is such.

Advantages of the Invention

[0015] According to the present invention, by combining GNSS measurement technology and 3D data measurement technology using 3D data measurement means on the ground or in the air, a system capable of performing 3D surface displacement measurement in the measurement of 3D data having coordinate values measured by GNSS measurement using an air target (calibration point) with determined coordinate values can be provided, which has an excellent effect. <00^0113> That is, the "points" measured by a plurality of GNSS antennas can be continuously used as calibration points or verification points, which are air targets with determined coordinate values. By performing measurement of 3D data using 3D data measurement means such as drone measurement using these plurality of air targets, it is possible to provide a 3D displacement measurement system that enables 3D surface displacement measurement while reducing the measurement labor of air targets with determined coordinate values.

[0017] This system eliminates the need to measure each aerial marker with surveying equipment such as a total station and form an aerial marker with determined coordinate values ​​each time. Unlike the systems shown in Japanese Patent Publication No. 2018-146546 and Japanese Patent Publication No. 2020-052029, which have issues such as the aerial marker installation jig only operating for short periods using a built-in battery, lacking dustproof and waterproof functions to withstand long-term outdoor use, and not having the structural durability to allow people or vehicles to pass directly above the aerial marker installation jig, this system allows for the construction of a displacement measurement system that does not require the installation or removal of the aerial marker installation jig, or position measurement using surveying equipment such as a total station, each time a continuous, periodic measurement, such as drone measurement, is performed. [Brief explanation of the drawing]

[0018] [Figure 1] This is a schematic diagram (1) illustrating the general configuration of the present invention. [Figure 2] This is a schematic diagram (2) illustrating the general configuration of the present invention. [Figure 3] This is a schematic diagram (3) illustrating the general configuration of the present invention. [Figure 4] This is a diagram illustrating the configuration of the aerial marker unit of the present invention. [Figure 5] This is an explanatory diagram illustrating specific examples of measurement markers. [Figure 6] This is an explanatory diagram illustrating an example of the installation of an aerial marker. [Modes for carrying out the invention]

[0019] The present invention includes a control device 23 as shown in Figure 1, which comprises a receiving unit 31 for transmitting and receiving signals and data, a transmitting unit 32, a control unit 28 for inputting and processing position information signals 22 received by a GNSS antenna 1 or 3D data obtained from 3D data measurement means such as a ground or airborne drone 36, such as 3D point cloud data, a data storage unit 33 for storing the processed data, a display unit 34 such as a display, and an input unit 35 such as a keyboard.

[0020] The system is constructed to measure the displacement of a predetermined measurement area by using both GNSS measurement technology (see Figure 2) and 3D data acquisition and measurement technology (see Figure 3) that uses 3D data based on aerial photographic data from a drone 36, for example, 3D point cloud data, which can be acquired from ground or aerial 3D data measurement means. The data obtained from these methods is processed by the control device 23.

[0021] In other words, the system transmits position information signals 22 from a GNSS satellite 16 to multiple GNSS antennas 1 installed in a measurement area 21 on the ground to be measured for displacement. The GNSS antennas 1 receive the position information signals 22, analyze the measured antenna installation positions, and acquire ground reference points with position coordinates. Subsequently, these ground reference points are photographed from the air, for example by a drone 36, to acquire 3D data based on photographic data, such as 3D point cloud data. When generating 3D data with position coordinates using this 3D data, such as the 3D point cloud data, the ground reference points acquired by the GNSS measurement technology can be used as control points 18 and verification points 19 with determined position coordinates.

[0022] Therefore, in the present invention, for example, in photogrammetry performed by aerial photography with a drone 36, the work of measuring a control point 18 having position coordinates each time 3D data, i.e., 3D point cloud data, is acquired multiple times in a predetermined measurement area 21 is eliminated. In other words, the effort required to measure the control points 18, which have position coordinates, can be significantly reduced, and accurate displacement measurements can be automatically, continuously, and periodically performed using 3D images with determined position coordinates.

[0023] With the above configuration, the positional coordinate information (ground reference point) of the installation position of the GNSS antenna 1 measured by GNSS measurement technology can be substituted as a control point 18 with positional coordinates used for measuring 3D point cloud data based on aerial photographs taken by a drone 36, etc. Using the substituted control point 18, 3D data with positional coordinates, i.e., 3D point cloud data with actual scale, can be generated and acquired. Furthermore, the displacement of the measurement area 21 can be reliably measured by the fluctuations of the 3D point cloud data with positional coordinates that are generated multiple times apart.

[0024] In this invention, a measurement mark pattern is painted on the surface of the lid of the control point forming member 2, which is positioned above the GNSS antenna 1, and this measurement mark 20 is used as a marker for acquiring the control point 18 having the position coordinates. Furthermore, the cover of the control point forming member 2, i.e., the surface of the measurement marker 20, is installed so as to be substantially flush with the ground surface 25, so that the installation of the control point forming member 2 does not obstruct the passage of people or vehicles.

[0025] Furthermore, if a tilt sensor 8 capable of detecting the tilt of the embedded GNSS antenna 1 is installed on the embedded GNSS antenna 1, then even if the GNSS antenna 1 tilts due to ground movement, for example, the correction of the position coordinate values ​​acquired from the control point 18 can be corrected by the correction unit 26 in the control unit 28 using the data detected by the tilt sensor 8.

[0026] Figures 1 to 4 are schematic diagrams illustrating the system configuration of the present invention. As can be seen from Figures 1 to 4, within the measurement area 21, there are multiple marker devices (aerial marker units 17) installed to surround the measurement area 21, and a GNSS antenna 1 is installed inside each aerial marker unit 17. Furthermore, as can be seen from Figures 2 and 3, the multiple aerial marker units 17 are connected to an external power supply 15 so that power can be continuously supplied to them. Therefore, the power used for the GNSS antenna 1 or the power used for the control unit and transmitting / receiving unit (not shown) of the aerial marker unit 17 is not supplied by an internal battery, so power can be supplied reliably and safely for a long period of time, thereby enabling smooth operation of the displacement measurement system.

[0027] Multiple GNSS antennas 1 receive position information signals 22 from GNSS satellites 16. The received position information signals 22 are transmitted from the transmission unit of the ground targeting beacon unit 17 via the receiving unit 31 of an external control device 23 to the GNSS antenna coordinate value analysis unit 24 in the control unit 28, which analyzes the coordinate values ​​of the GNSS antenna installation locations. This transmission may be performed via the internet 37, or it may be configured to transmit directly.

[0028] Then, the coordinate value analysis unit 24 of the antenna detects the coordinate values ​​of the installation position of the GNSS antenna 1.

[0029] Incidentally, the GNSS antenna 1 is housed and mounted inside the ground control point forming member 2, which is a component of the ground control beacon section 17. The ground control beacon section 17 is composed of the ground control point forming member 2, the GNSS antenna 1 mounted inside the ground control point forming member 2, and a measurement mark 20 formed on the surface of the lid of the ground control point forming member 2. Figure 4 shows its detailed configuration.

[0030] The GNSS antenna 1 according to the present invention is configured to have a substantially disc-shaped antenna body 3 and a fixing rod-shaped part 4 that is connected to and hangs down from approximately the center of the bottom of the antenna body 3.

[0031] Reference numeral 5 denotes a fixing device for fixing the GNSS antenna 1, and the fixing device 5 has a fixing hole 6 in its center through which the fixing rod-shaped part 4 is inserted to fix the antenna body part 3. The ground control point forming member 2 is also a container-shaped member that fixes and houses the GNSS antenna 1 in a predetermined position.

[0032] The ground control point forming member 2 is composed of a first container component and a second container component 10, both of which are roughly cylindrical in shape. However, the ground control point forming member 2 does not have to be composed of multiple components; it may be composed of a single cylindrical container-like component. Furthermore, while the ground control point forming member 2 is usually composed of a cylindrical box, it is not limited to a box.

[0033] The first container component 7 is configured to be substantially cylindrical and is buried in the ground to fix the GNSS antenna 1. That is, the ground is excavated at a predetermined location, and the fixing device 5, to which the fixing rod-shaped portion 4 of the GNSS antenna 1 is inserted and fixed, and the first container component 7 are installed at the excavated location.

[0034] Here, it is preferable that the fixing device 5 is connected to and integrated with the first container component 7, but it is not necessary for them to be integrated. A tilt sensor 8 is attached to the fixing device 5.

[0035] As shown in Figure 4, it is preferable to interpose a moisture-absorbing material 9, such as sand, between the bottom portion of the first container component 7 and between the first container component 7 and the fixing device 5 to protect the GNSS antenna 1.

[0036] A connection portion 13 for connecting to a substantially cylindrical second container component 10 is formed on the upper surface of the first container component 7. The connection portion 13 is formed on the upper surface of the first container component 7 by having an inwardly bent stepped piece 11 and a protruding piece 12 that rises substantially vertically from the tip of the stepped piece 11.

[0037] However, the lower part of the second container component 10, which is substantially cylindrical, is fitted into the connecting portion 13 and connected, thereby forming a storage container-shaped reference point forming member 2 with the connected first container component 7 and second container component 10.

[0038] Furthermore, when the lower part of the second container component 10, which is substantially cylindrical, is fitted into the connecting portion 13 for connection, a sealing material is interposed between the outer surface of the protruding piece 12 of the first container component 7 and the lower inner surface of the second container component 10, and a sealing ring 14 is attached to the lower outer surface of the second container component 10 and tightened, thereby ensuring the integration of the first container component 7 and the second container component 10.

[0039] As shown in Figure 4, the inside of the second container component 10 is a storage space for housing the roughly disc-shaped antenna body 3 of the GNSS antenna 1, and unlike the inside of the first container component 7 which was installed earlier, the moisture-absorbing material 9 is not filled inside.

[0040] Reference numeral 20 denotes a measurement mark provided on the surface of the lid of the control point forming member 2. The lid on which the measurement mark 20 is provided is installed so as to close the upper opening of the second container component 10 on which it is installed. It is important that the lid on which the measurement mark 20 is provided is made of a material that allows the position information signal 22 from the GNSS satellite 16 to be received by the GNSS antenna 1. In other words, it must not be made of a material that blocks the position information signal 22 from reaching the GNSS antenna 1 installed inside the control point forming member 2.

[0041] Furthermore, since the measurement area 21 is an area over which people or vehicles must pass, it is also required that the material be able to withstand the load. The type of material is not limited as long as the above requirements are met. An example is a lid for the ground control point shape 1 component 2 made of a synthetic resin material with a certain degree of rigidity.

[0042] As described above, by adopting an underground installation method for the ground control point forming member 2, all members and devices for forming the ground control point are installed underground. Therefore, it does not spoil the landscape of the measurement area 21 and does not become an obstacle for people or vehicles passing directly above the aerial marker section 17.

[0043] The patterns of the measurement marker 20 are shown in Figure 5, and any of these patterns are acceptable. Furthermore, patterns such as star shapes, X shapes, plus shapes, circles, or any other arbitrary shapes may be painted on them. It is preferable to select a color scheme for the measurement marker 20 that provides good visibility from above. This is because the measurement marker 20 used for measuring control points needs to be recognizable from the ground and from the air by three-dimensional measurement means such as drones 36, and therefore the measurement marker 20 must always be installed exposed on a surface such as the ground surface. This is a significant difference from when the GNSS satellite 14 transmits a position information signal 22 to the GNSS antenna 1, where the GNSS antenna 1 does not necessarily need to be exposed on the surface; as long as the position information signal 22 can be received, the GNSS antenna 1 may be installed in a location hidden from the surface. The present invention can be said to have been created by taking advantage of this difference. In addition, if the landscape is a consideration, a color similar to the surrounding environment may be selected.

[0044] As shown in Figure 4, the receiving position where the GNSS antenna 1 receives the position information signal 22, i.e., the antenna installation position, is different from the position of the ground control point used for aerial photogrammetry, i.e., the installation position of the measurement 21 provided on the lid surface of the ground control point forming member 2. Therefore, this difference is recognized in advance as a correction coefficient, and the position coordinate analysis of the ground control point is performed accordingly.

[0045] As shown in Figure 3, the coordinate value analysis unit 24 analyzes the position coordinates of the antenna installation location. This analysis value is then processed by the correction unit 26, which adds the correction coefficient, and the coordinate value analysis unit 27 analyzes it, generating a control point 18 with determined position coordinates for use in aerial photographic measurement.

[0046] In other words, when measuring the GNSS antenna 1, the coordinates of the center of the top surface of the antenna body 3 are measured. On the other hand, when measuring aerial photographs, such as with a drone 36, the coordinates of the center of the measurement marker 20 are required. As mentioned above, the center position of the top surface of the antenna body 3 and the center position of the measurement marker 20 are separated in the vertical direction and do not coincide. Therefore, for the initial measurement only, for example, the center position of the measurement marker 20 is measured using a measuring instrument, and the offset values ​​in the x, y, and z directions of the centers of both are obtained.

[0047] Then, from the second time onward, by performing a correction control by the correction unit 26 that adds the acquired offset value to the coordinate value of the center position of the GNSS antenna 1, the coordinate value of the center position of the measurement marker 20, i.e., the ground control point 18, can be obtained.

[0048] As mentioned above, the correction unit 26 receives tilt data from the tilt sensor 8, which can detect the tilt of the GNSS antenna 1, and is configured to correct the position coordinate values ​​acquired from the control point 18 in order to respond when the GNSS antenna 1 tilts due to ground movement or the like. Furthermore, if there is a device or method that can measure the rotation caused by the tilt of the GNSS antenna 1 with respect to the x, y, and z axes, the correction device is not limited to the tilt sensor 8.

[0049] Furthermore, the ground control unit 17 itself may move due to ground deformation, causing the position coordinate information measured by the GNSS satellite 16 and GNSS antenna 1 to continuously shift and change. However, data for these shifts is also sent from the ground control unit 17 or the GNSS satellite 16 to the control device 23, where it can be analyzed by the correction unit 26. This correction control is also performed by the correction unit 26.

[0050] As described above, in this invention, each offset information can be acquired and the measured position coordinates can be corrected and controlled. Therefore, even if the installation position of the GNSS antenna 1 moves or is displaced, the movement or displacement can be corrected and the position coordinates of the control point 18 can be determined in real time with high accuracy.

[0051] Incidentally, it is also conceivable to install the GNSS antenna 1 itself so that it is exposed and flush with the ground surface 25. If installed in this way, the surface of the GNSS antenna 1 can be directly used as a measurement marker 20 when taking aerial photographs with a drone 36, eliminating the need for the offset correction mentioned above. However, with such a configuration, there may be cases where people or vehicles have to drive over it, and the GNSS antenna 1 cannot withstand the weight. Furthermore, there are also problems with long-term durability.

[0052] Therefore, in this invention, the GNSS antenna 1 that receives the position information signal 22 is positioned below the ground surface, and to protect the GNSS antenna 1, it is covered with a lid, and a measurement marker 20 for measuring ground control points is formed on the surface of the lid. In other words, although the position information signal 22 reaches the GNSS antenna 1 through the lid, in the case of acquiring 3D data such as aerial photography, 3D data such as 3D point cloud data cannot be acquired unless the measurement marker 20 is exposed on the ground surface. This is a major feature of this invention.

[0053] However, using the control point 18 whose coordinate values ​​have been determined, 3D data, such as 3D point cloud data, is acquired by aerial photography from the air or the ground, and 3D data with determined coordinate values, such as 3D point cloud data, is generated from this 3D data by the generation unit 29 of the control unit 28 in the control device 23.

[0054] Furthermore, the generation unit 29 generates 3D data with multiple determined coordinate values, such as 3D point cloud data, by taking multiple aerial photographs from the air or ground at intervals, and the displacement of the measurement area 21 can be measured by the displacement measurement unit 30 from the generated 3D data with multiple determined coordinate values, such as 3D point cloud data.

[0055] By the way, when analyzing aerial photographs taken with a drone 36 or the like, coordinate values ​​are assigned to the 3D data using measurement markers 20, but it is not necessary to assign coordinate values ​​to all measurement markers 20.

[0056] As shown in Figure 6, the aerial marker section 17, which has a measurement mark 20 on its surface, has both a control point 18 and a verification point 19. The control point 18 is used to assign coordinate values ​​to 3D data, but the verification point 19 is not assigned coordinate values. This is because the verification point 19 is used to calculate the analysis accuracy of the 3D data that has generated coordinate values, based on the difference between the measured value and the analyzed value. The aforementioned calculation is also performed by the correction unit 26.

[0057] Incidentally, by equipping the drone 36 with a 3D laser scanner, it is also possible to acquire wide-area 3D data, such as 3D point cloud data, from above. Therefore, the present invention is not limited to photogrammetry using the drone 36. Furthermore, this invention makes it possible to measure displacement even in locations where ground-based laser scanners or MMS cannot measure, or in areas where aerial photogrammetry is unsuitable, such as mountainous forests.

[0058] (summary) This invention involves performing aerial photography from multiple locations on a ground-based measurement target area using a flying object such as a drone 36. From the 3D data acquired by the aerial photography, such as 3D point cloud data, the shape of the target area is initially obtained in 3D.

[0059] Then, by assigning coordinate values ​​to the measurement markers 20 in the acquired 3D data, for example, 3D point cloud data, the coordinate system is determined, and the acquired 3D data, for example, 3D point cloud data, can have a scale. Therefore, assigning coordinate values ​​to the measurement markers 20 is essential. In this invention, the assignment of these coordinate values ​​was performed using a GNSS measurement method.

[0060] In other words, the GNSS satellite 16 transmits a position information signal 22, and the GNSS antenna 1 on the ground receives the position information signal 22. The installation position of the GNSS antenna 1 on the ground then has a continuous set of coordinate values, and these coordinate values ​​were used as substitutes for the coordinate values ​​of the 3D data acquired by aerial photography.

[0061] As mentioned above, conventionally, it was necessary to measure each aerial marker with a total station (measuring instrument) and form an aerial marker section 17 to which coordinate values ​​were assigned. However, this method is extremely labor-intensive.

[0062] Therefore, in this invention, we have developed an aerial beacon unit 17 that incorporates a GNSS antenna 1 for receiving position information signals 22 transmitted from a GNSS satellite 16. Furthermore, the conventional anti-aircraft markers were limited to operation using an internal battery, which only lasted for a few hours, but this issue has also been resolved.

[0063] Furthermore, the system solves previous problems such as the difficulty of automatically uploading and saving measured coordinate values, the necessity of installing and removing the battery-powered aerial marker 17 for each drone measurement, the inability to operate for extended periods due to battery operation, and the inability to leave it in place or operate continuously for extended periods in outdoor environments.

[0064] In other words, in this invention, a control point forming member 2 in the shape of a container formed from, for example, a wooden box is embedded in the area to be measured (for example, within a golf course), a GNSS antenna 1 is installed inside the control point forming member 2, and a measurement mark 20 is formed on the lid surface of the control point forming member 2 to constitute an aerial marker section 17. The measurement mark 20 is formed by painting the surface of the lid with a predetermined pattern.

[0065] As a result, the present invention enables the continuous and automatic measurement of the three-dimensional displacement at the installation location of the aerial marker unit 17. Furthermore, the measurement results can be quickly and reliably transmitted and distributed via the Internet 37 or other means.

[0066] Furthermore, by painting the surface of the lid of the control point forming member 2 with an aerial marker pattern, the work that would normally be required for each drone measurement could be eliminated. Furthermore, this invention enables long-term continuous automatic measurement of so-called three-dimensional displacement. It also enables long-term automatic measurement of the coordinate values ​​of the aerial marker unit 17, and even if the ground surface 25 changes, the amount of movement can be acquired. Furthermore, since it is powered by an external power supply 15 via a power cable, it can operate for extended periods. Furthermore, the aerial marker section 17 has improved dustproof, waterproof, and durable properties, allowing for long-term use in outdoor environments and enabling long-term outdoor storage.

[0067] In other words, the present invention makes it possible to repeatedly and regularly measure displacement in the measurement area 21 at a high frequency, and can be used, for example, for measuring ground surface settlement in civil engineering works, for periodic observation of other ground displacements, and for calculating soil volume in earthworks.

[0068] Incidentally, while the present invention has shown an example in which 3D point cloud data is measured and processed using a 3D data measurement means such as a drone 36, the 3D data to be measured is not limited to 3D point cloud data. In other words, if there is other preferable 3D data that can be measured, that 3D data may be used for data measurement and data processing. [Explanation of Symbols]

[0069] 1 GNSS antenna 2 Control point forming member 3. Antenna main unit 4 Fixing rod part 5 Fixtures 6 Fixing holes 7. First container component 8. Tilt sensor 9. Moisture absorber 10 Second container component 11 Step piece 12 Projecting piece 13 Connection part 14 Ceiling rings 16 GNSS satellites 17. Aerial marker section 18 Control points 19 Points of Verification 20 Measurement Markers 21 Measurement Area 22 Location information signal 23 Control device 24 Antenna Coordinate Value Analysis Unit 25 Ground surface 26 Correction section 27. Coordinate Value Analysis Unit for Control Points 28 Control Unit 29 Generation part 30 Displacement measurement unit 31 Receiver 32 Transmitter 33 Data storage unit 34 Display section 35 Input section 36 Drones 37 Internet

Claims

1. A displacement measurement system using both GNSS measurement technology and 3D data measurement technology using ground and air-based 3D data measurement means, wherein the system has an antenna capable of receiving position information signals transmitted from a GNSS satellite and acquiring position coordinates, the installation position of the antenna that acquired the position coordinates is used as a substitute for a control point having position coordinates used for 3D data measurement, the substituted control point is used to measure 3D data having position coordinates multiple times at intervals to generate multiple 3D data sets, and the displacement of the measurement area is measured by the control unit based on the fluctuations in the multiple generated 3D data having position coordinates, The antenna is constructed with a roughly disc-shaped antenna body and a fixing rod-shaped part that is connected to and hangs down from approximately the center of the bottom of the antenna body. It is housed in a location excavated in the ground, with the antenna body extending horizontally and positioned below the ground surface. A cover is attached directly above the antenna body, which closes the upper opening of the excavation and is made of a material that allows the antenna to receive position information signals from GNSS satellites. Measurement markers for control points used in the three-dimensional data measurement are provided on the surface of the cover. A three-dimensional displacement measurement system characterized by the following features.

2. The means for measuring three-dimensional data from the ground and air is three-dimensional data measurement from the ground and air using a drone. The three-dimensional displacement measurement system according to claim 1, characterized in that it is the same as described in claim 1.

3. A measurement mark pattern is painted on the surface of the lid to form a measurement mark, and the measurement mark is used as a marker for obtaining a ground control point having the position coordinates. The three-dimensional displacement measurement system according to claim 1, characterized in that it is the same as described in claim 1.

4. The cover is installed so as to be substantially flush with the ground surface. The three-dimensional displacement measurement system according to claim 1, characterized in that it is the same as described in claim 1.

5. The three-dimensional data to be measured is three-dimensional point cloud data. The three-dimensional displacement measurement system according to claim 1, characterized in that it is the same as described in claim 1.

6. The antenna is fixed and mounted within a container-shaped ground point forming member housed in the excavation site. The three-dimensional displacement measurement system according to claim 1, characterized in that it is the same as described in claim 1.

7. The antenna is installed inside a ground control point forming member of an excavation site excavated in a place where vehicles and people pass by, The three-dimensional displacement measurement system according to claim 6, characterized in that it is as described above.

8. A moisture-absorbing material for protecting the antenna is attached to a container-shaped ground point forming member housed in the excavation site. The three-dimensional displacement measurement system according to claim 6, characterized in that it is as described above.

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