A device and method for measuring the volume of a pilot pit for testing roadbed compaction

Abstract

The invention relates to the technical field of volume measurement, and provides a device and a method for measuring the volume of a test pit in roadbed compaction detection. A laser scanning module scans and obtains point cloud data in a test pit and transmits it to a data preprocessing module; the data preprocessing module performs denoising according to a radius outlier filtering algorithm after receiving the point cloud data; a data calculation module receives the preprocessed data, calculates the point cloud data information, and iteratively calculates the zero isosurface of the level set function representing the surface of the test pit, and then uses Gauss-Green's theorem to perform volume calculation; a data display module displays the boundary image, volume and point cloud data image of the test pit area according to the calculation result; the invention obtains point cloud data through a laser scanning module, and after filtering and denoising by the data preprocessing module, the data calculation module constructs a level set function and determines the boundary of the test pit with the help of partial differential equation evolution, and then uses Gauss-Green's theorem to calculate the volume, so as to achieve the measurement of the precise volume of the irregular test pit.

Description

Technical Field

[0001] The invention relates to the technical field of volume measurement, in particular to a volume measurement device for a pilot pit for roadbed compaction detection and a measurement method thereof. Background Art

[0002] The roadbed compaction test is generally carried out by sand filling method and water filling method. The principle is to calculate the density by volume and mass. A circular test pit with a diameter of 15cm and a depth of 20cm is dug for the compacted roadbed, and the density is calculated by the volume and mass of the excavated soil.

[0003] For the calculation of the test pit volume, the test process takes the sand filling method as an example. After the test pit is dug, standard sand of known density is poured into the test pit by free fall through a special sand tank. The mass of the sand poured is then calculated, and the volume is calculated using the known density and mass. The volume of the test pit is then obtained. The mass of the soil dug out of the test pit is then weighed to calculate the density of the soil in the test pit.

[0004] However, in the prior art, the operation process of filling with sand and water is relatively complicated. Therefore, an optical device can be used to perform spatial scanning on the test pit to obtain the actual volume of the test pit.

[0005] However, since the surface of the test pit is not smooth and flat but irregular and rough, it is difficult for existing technologies to accurately mathematically model and calculate this complex surface morphology, which to a certain extent affects the accuracy of the test pit volume calculation, and in turn has an adverse effect on the accuracy of the roadbed compaction and humidity test results. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a volume measurement device and a measurement method for a pilot pit for roadbed compaction detection. Point cloud data is acquired by a laser scanning module. After filtering and noise reduction by a data preprocessing module, a level set function is constructed by a data calculation module and the boundary of the pilot pit is determined with the help of partial differential equation evolution. The volume is then calculated using Gauss-Green's theorem to achieve accurate volume measurement of irregular pilot pits, thereby solving the problems in the prior art.

[0007] A device for measuring the volume of a pilot pit for detecting roadbed compaction, comprising:

[0008] A laser scanning module, wherein the laser scanning module uses a laser scanner and can perform an all-round scan of the inside of the test pit at different angles and distances to obtain point cloud data of the test pit;

[0009] A data preprocessing module, which is connected to the laser scanning module by data, is responsible for receiving the point cloud data collected by the laser scanner, preprocessing the point cloud data based on a radius outlier filtering algorithm, and removing data noise caused by dust in the test pit;

[0010] A data calculation module, which is data-connected to the data preprocessing module, is used to receive the preprocessed point cloud data, determine the test pit surface according to the point cloud information evolution level set function; and then calculate the total volume of the test pit based on the test pit surface by Gauss-Green's theorem;

[0011] The data display module is data-connected to the data calculation module and the laser scanning module, and is used to display the specific area boundary image and volume of the test pit according to the calculation results of the data calculation module, as well as the point cloud data image scanned by the laser scanning module.

[0012] Preferably, the specific denoising process of the data preprocessing module based on the radius outlier filtering algorithm is as follows:

[0013] Assume that the test pit point cloud data set obtained by the laser scanning module is ,in The coordinates of , The coordinates of , i and j are two indexes of point cloud data points, point cloud data set The total number of inner point cloud data points is ;

[0014] Set the radius r and threshold m. The radius r is determined by the size of the test pit and the resolution of the point cloud data. The threshold m is determined based on experience or testing of some data. Specifically, 1%-5% of the test pit diameter is taken as the initial value of the radius r, and a value between 3 and 10 is taken as the initial value of the threshold m.

[0015] For each point in the point cloud data , calculated with The number of points contained in a sphere with a center and a radius of r ;

[0016] First, by traversing the point cloud data set P, for each point , to determine whether it is in In a sphere with a center and a radius of r, the distance formula is:

[0017] ;

[0018] in, Yes With point If the distance between , then the point Recorded as The points contained in the sphere with a center and a radius of r; after calculating all the points After that, if , then the point Mark as noise points or dust points and remove them;

[0019] Finally, all points marked as noise points are removed from the original point cloud data set P to obtain the denoised point cloud data set. .

[0020] Preferably, the data calculation module includes a surface calculation unit and a volume calculation unit;

[0021] The surface calculation unit receives the preprocessed point cloud data, initializes the level set function to construct the distribution according to the point-to-point distance and direction rules of the point cloud data points in a specific initial area, and then evolves the level set function using a partial differential equation to obtain the zero isosurface of the level set function representing the surface of the test pit;

[0022] The volume calculation unit calculates the normal vector of the gradient of the zero isosurface based on the zero isosurface calculated by the surface calculation unit and based on Gauss-Green's theorem, and then performs an integral operation to divide the test pit area into small cubic spaces, calculates the volume in the cubic space by the finite difference method, and sums them up to obtain the test pit volume.

[0023] Preferably, the surface calculation unit represents the surface of the test pit by calculating the zero isosurface in the level set function. The specific calculation process is as follows:

[0024] Determine the initial region H containing the test pit. This region is a rectangular region slightly larger than the minimum bounding box of the test pit. Initialize the level set function in region H. The level set function is a function defined in three-dimensional space. For each point in space , the function has a corresponding function value; suppose after calculation, the point ;

[0025] For other points in region H , calculate Q to the nearest point cloud data point distance;

[0026] ;

[0027] If Q is In the direction of the normal vector pointing outside the region H, then ; if in the opposite direction, then ; By calculating all points in region H, the level set function is assigned to the entire region Corresponding initial values, a function distribution reflecting the space and surface conditions of the test pit is preliminarily constructed;

[0028] Then, the level set function is analyzed by using the evolution method based on partial differential equations. Perform update iterations and finally obtain a level set function equal to 0 , the level set function at this time is the zero isosurface, that is, the surface of the test pit, that is, the test pit area The boundary of the test pit is expressed as .

[0029] Preferably, the volume calculation unit calculates the test pit volume V according to Gauss-Green's theorem:

[0030] ;

[0031] in is the position vector, It is the boundary of the test pit area , which is the unit external normal vector of the test pit surface, and S is used to indicate that the formula is on the test pit surface. The surface integral is performed on the surface, V represents the volume of the test pit, d is the differential element identifier in the integral operation, represents the gradient operator;

[0032] Since the level set function The zero contour surface is the test pit surface , by calculating the zero isosurface of the level set function Finding the Gradient Get the unit external normal vector:

[0033] ;

[0034] but

[0035] ;

[0036] Then use the divergence theorem to convert the above surface integral into volume integral:

[0037] ;

[0038] The area Divide into small cubic spaces , whose side lengths are and , where a, b, and c are units Indexes of the x-axis, y-axis, and z-axis directions in three-dimensional space;

[0039] Then for each unit , the center coordinates are , the integral term is calculated by discrete approximation based on the finite difference method The value of , and then calculate the volume within each unit ;

[0040] ;

[0041] Finally, the test pit volume V:

[0042] ;

[0043] That is, the volume of all units The sum is the volume of the test pit.

[0044] Preferably, the laser scanning module also includes a high-definition camera for further collecting images and information inside the test pit and transmitting them to the data display module for staff to compare and verify the data and images.

[0045] Preferably, the data display module is also equipped with a built-in wireless transmission unit, which can remotely transmit the displayed data and images to other terminal devices, making it convenient for multiple people to view.

[0046] A method for measuring the volume of a pilot pit for roadbed compaction detection, comprising:

[0047] Step 1: Measurement preparation: Place the laser scanning module in the measurement device near the test pit to ensure that the laser scanning module can cover the entire test pit range;

[0048] Step 2, data acquisition, start the laser scanning module, scan the test pit at multiple angles and multiple levels, and obtain a large amount of discrete point cloud data on the test pit surface, including point cloud data of the inner wall, bottom, and rough and irregular parts of the test pit. At the same time, the laser scanning module transmits the point cloud data to the data preprocessing module;

[0049] Step 3, data preprocessing, the data preprocessing module receives the point cloud data, calculates and removes dust noise points according to the radius outlier filtering algorithm, and transmits the retained point cloud data to the data calculation module;

[0050] Step 4: Determine the boundary of the test pit. The surface calculation unit of the data calculation module obtains the retained point cloud data, demarcates the initial area around the test pit, initializes the level set function, assigns an initial value by calculating the distance between the point and the point cloud data point and combining the direction condition, and obtains the zero isosurface of the level set function through the partial differential equation evolution to determine the surface of the test pit.

[0051] Step 5, volume numerical calculation, the volume calculation unit first calculates the normal vector of the boundary gradient based on the determined test pit surface and with the help of Gauss-Green's theorem, converts the integral form and divides the calculation area into a cubic space, calculates the volume of the cubic space by the finite difference method and sums them up to obtain the total volume of the test pit;

[0052] Step 6, result display, the data display module presents the boundary image, volume data and point cloud data image of the test pit area, and through the wireless transmission unit, the data and images can be received by the remote terminal to achieve shared viewing by multiple people.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] 1. The present invention uses a laser scanning module to perform an all-round scanning of the test pit to obtain point cloud data, a data preprocessing module to remove noise data, and a data calculation module to construct a level set function based on the point cloud information and determine the test pit surface using the evolution of partial differential equations. The Gauss-Green theorem and the finite difference method are then used to calculate the volume, thereby realizing an integrated process from data collection to precise volume calculation for irregular and rough test pits, accurately calculating the shape and volume of the test pit, overcoming the problem of the prior art that it is difficult to accurately model and calculate due to the unevenness of the test pit, and improving the accuracy and reliability of the roadbed compaction detection data.

[0055] 2. The present invention displays laser scanning images, trial pit area boundary images and volume data through a data display module, and realizes multi-person sharing with the help of wireless transmission function, as well as the rigorous and efficient calculation process of the data calculation module, thereby realizing the collaborative optimization of data processing, display and sharing, simplifying the cumbersome process of the traditional sand and water filling method, and facilitating multi-person collaborative work and result analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is the working flow chart of the device of the present invention;

[0057] Figure 2 is a flow chart of the steps of the method of the present invention;

[0058] Figure 3 It is a schematic diagram of the specific calculation flow of the data calculation module of the present invention. DETAILED DESCRIPTION

[0059] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0060] The present invention provides a device for measuring the volume of a pilot pit for detecting roadbed compaction, comprising:

[0061] A laser scanning module, wherein the laser scanning module uses a laser scanner and can perform an all-round scan of the inside of the test pit at different angles and distances to obtain point cloud data of the test pit;

[0062] A data preprocessing module, which is connected to the laser scanning module by data, is responsible for receiving the point cloud data collected by the laser scanner, preprocessing the point cloud data based on a radius outlier filtering algorithm, and removing data noise caused by dust in the test pit;

[0063] A data calculation module, which is data-connected to the data preprocessing module, is used to receive the preprocessed point cloud data, determine the test pit surface according to the point cloud information evolution level set function; and then calculate the total volume of the test pit based on the test pit surface by Gauss-Green's theorem;

[0064] The data display module is data-connected to the data calculation module and the laser scanning module, and is used to display the specific area boundary image and volume of the test pit according to the calculation results of the data calculation module, as well as the point cloud data image scanned by the laser scanning module.

[0065] A method for measuring the volume of a pilot pit for roadbed compaction detection, comprising:

[0066] Step 1: Measurement preparation: Place the laser scanning module in the measurement device near the test pit to ensure that the laser scanning module can cover the entire test pit range;

[0067] Step 2, data acquisition, start the laser scanning module, scan the test pit at multiple angles and multiple levels, and obtain a large amount of discrete point cloud data on the test pit surface, including point cloud data of the inner wall, bottom, and rough and irregular parts of the test pit. At the same time, the laser scanning module transmits the point cloud data to the data preprocessing module;

[0068] Step 3, data preprocessing, the data preprocessing module receives the point cloud data, calculates and removes dust noise points according to the radius outlier filtering algorithm, and transmits the retained point cloud data to the data calculation module;

[0069] Step 4: Determine the boundary of the test pit. The surface calculation unit of the data calculation module obtains the retained point cloud data, demarcates the initial area around the test pit, initializes the level set function, assigns an initial value by calculating the distance between the point and the point cloud data point and combining the direction condition, and obtains the zero isosurface of the level set function through the partial differential equation evolution to determine the surface of the test pit.

[0070] Step 5, numerical calculation of volume. The volume calculation unit first calculates the normal vector of the boundary gradient based on the determined test pit surface and uses Gauss-Green's theorem. After converting the integral form, the calculation area is divided into a cubic space. The volume of the cubic space is calculated and summed up by the finite difference method to obtain the total volume of the test pit.

[0071] Step 6, result display, the data display module presents the boundary image, volume data and point cloud data image of the test pit area, and through the wireless transmission unit, the data and images can be received by the remote terminal to achieve shared viewing by multiple people. Example

[0072] like Figure 1-Figure 3 As shown, in this embodiment, in a roadbed compaction test project, the construction personnel first dig a circular test pit with a diameter of about 15 cm and a depth of about 20 cm on the compacted roadbed according to standard specifications.

[0073] Subsequently, the laser scanning module of the measuring device was turned on, and the laser scanner performed a comprehensive scan of the inside of the test pit. At the same time, the high-definition camera synchronously recorded the image information inside the test pit. During the scanning process, the laser scanner started from the top of the test pit and gradually rotated to the bottom at a scanning interval of 0.5 degrees, performing detailed scans at different height levels to ensure that complete and detailed point cloud data was obtained.

[0074] The laser scanning module greatly improves the integrity and accuracy of the point cloud data, laying a solid foundation for the subsequent precise calculation of the test pit volume, avoiding calculation errors caused by missing or inaccurate data, and improving the reliability of the entire detection work.

[0075] Next, the data preprocessing module receives the point cloud data collected by the laser scanner and performs specific denoising based on the radius outlier filtering algorithm. The process is as follows:

[0076] Assume that the test pit point cloud data set obtained by the laser scanning module is ,in The coordinates of , The coordinates of , i and j are two indexes of point cloud data points, point cloud data set The total number of inner point cloud data points is ;

[0077] Set the radius r and threshold m. The radius r is determined by the size of the test pit and the resolution of the point cloud data. The threshold m is determined based on experience or testing of some data. Specifically, 1%-5% of the test pit diameter is taken as the initial value of the radius r, and a value between 3 and 10 is taken as the initial value of the threshold m.

[0078] For each point in the point cloud data , calculated with The number of points contained in a sphere with a center and a radius of r ;

[0079] First, by traversing the point cloud data set P, for each point , to determine whether it is in In a sphere with a center and a radius of r, the distance formula is:

[0080] ;

[0081] in, Yes With point If the distance between , then the point Recorded as The points contained in the sphere with a center and a radius of r; after calculating all the points After that, if , then the point Mark as noise points or dust points and remove them;

[0082] Finally, all points marked as noise points are removed from the original point cloud data set P to obtain the denoised point cloud data set. .

[0083] The surface calculation unit receives the denoised point cloud data and represents the surface of the test pit by calculating the zero isosurface in the level set function. The specific calculation process is as follows:

[0084] Determine the initial region H containing the test pit. This region is a rectangular region slightly larger than the minimum bounding box of the test pit. Initialize the level set function in region H. The level set function is a function defined in three-dimensional space. For each point in space , each function has a corresponding function value;

[0085] Assume that after calculation, point ;

[0086] For other points in region H , calculate Q to the nearest point cloud data point distance;

[0087] ;

[0088] If Q is In the direction of the normal vector pointing outside the region H, then ; if in the opposite direction, then ; By calculating all points in region H, the level set function is assigned to the entire region Corresponding initial values, a function distribution reflecting the space and surface conditions of the test pit is preliminarily constructed;

[0089] Then, the level set function is analyzed by using the evolution method based on partial differential equations. Perform update iterations and finally obtain a level set function equal to 0 , the level set function at this time is the zero isosurface, that is, the surface of the test pit, that is, the test pit area The boundary of the test pit is expressed as .

[0090] Through the surface calculation unit, mathematical calculations can be accurately performed on the irregular test pit surface, which solves the problem of difficulty in accurately determining the shape due to the uneven surface of the test pit, significantly improves the accuracy of determining the test pit shape, and thus provides a key basis for accurately calculating the volume.

[0091] Volume calculation unit based on test pit boundary , calculate the test pit volume V by Gauss-Green's theorem:

[0092] ;

[0093] in is the position vector, It is the boundary of the test pit area , which is the unit external normal vector of the test pit surface, and S is used to indicate that the formula is on the test pit surface. The surface integral is performed on the surface, V represents the volume of the test pit, d is the differential element identifier in the integral operation, represents the gradient operator;

[0094] Since the level set function The zero contour surface is the test pit surface , by calculating the zero isosurface of the level set function Finding the Gradient Get the unit external normal vector

[0095] ;

[0096] but

[0097] ;

[0098] Then use the divergence theorem to convert the above surface integral into volume integral:

[0099] ;

[0100] The area Divide into small cubic spaces , whose side lengths are and Among them, a, b, and c are units Indexes of the x-axis, y-axis, and z-axis directions in three-dimensional space;

[0101] Then for each unit , the center coordinates are , the integral term is calculated by discrete approximation based on the finite difference method The value of , and then calculate the volume within each unit ;

[0102] ;

[0103] Finally, the test pit volume V:

[0104] ;

[0105] That is, the volume of all units The sum is the volume of the test pit.

[0106] The volume calculation unit realizes efficient conversion from complex test pit shape data to accurate volume values. It can ensure high accuracy of volume calculation even when the test pit is uneven, and effectively avoid deviations in roadbed compaction and humidity test results caused by test pit volume errors.

[0107] Finally, the data display module receives and displays the area boundary image of the test pit, the calculated volume, and the point cloud data image of the laser scanning module. At the same time, it integrates and displays the image information collected by the high-definition camera, making it convenient for inspection personnel to intuitively compare and verify data and images.

[0108] In addition, using its built-in wireless transmission unit, these data and images can be remotely transmitted to other terminal devices in the project office for simultaneous viewing and analysis by project leaders, engineers and other multiple people.

[0109] In this way, the measuring device effectively solves the problem of cumbersome operation of traditional sand filling or water filling methods and difficulty in accurately modeling and calculating the volume of irregular test pit surfaces, greatly improving the efficiency and accuracy of roadbed compaction detection and providing reliable data support for road engineering quality assessment.

[0110] The embodiments of the present invention are provided for the purpose of illustration and description. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A device for measuring the volume of a pilot pit for detecting roadbed compaction, characterized in that: include: A laser scanning module, wherein the laser scanning module uses a laser scanner and can perform an all-round scan of the inside of the test pit at different angles and distances to obtain point cloud data of the test pit; A data preprocessing module, which is connected to the laser scanning module by data, is responsible for receiving the point cloud data collected by the laser scanner, preprocessing the point cloud data based on a radius outlier filtering algorithm, and removing data noise caused by dust in the test pit; A data calculation module, which is data-connected to the data preprocessing module, is used to receive the preprocessed point cloud data, determine the test pit surface according to the point cloud information evolution level set function; and then calculate the total volume of the test pit based on the test pit surface by Gauss-Green's theorem; The data display module is data-connected to the data calculation module and the laser scanning module, and is used to display the specific area boundary image and volume of the test pit according to the calculation results of the data calculation module, as well as the point cloud data image scanned by the laser scanning module.

2. A device for measuring the volume of a pilot pit for detecting roadbed compaction as claimed in claim 1, characterized in that: The specific denoising process of the data preprocessing module based on the radius outlier filtering algorithm is as follows: Assume that the test pit point cloud data set obtained by the laser scanning module is ,in The coordinates of , The coordinates of , and Two indexes of point cloud data points, point cloud data set The total number of inner point cloud data points is ; Set the radius r and threshold m. The radius r is determined by the size of the test pit and the resolution of the point cloud data. The threshold m is determined based on experience or testing of some data. Specifically, 1%-5% of the test pit diameter is taken as the initial value of the radius r, and a value between 3 and 10 is taken as the initial value of the threshold m. For each point in the point cloud data , calculated with The number of points contained in a sphere with a center and a radius of r ; First, by traversing the point cloud data set P, for each point , to determine whether it is in In a sphere with a center and a radius of r, the distance formula is: ； in, Yes With point If the distance between , then the point Recorded as The points contained in the sphere with a center and a radius of r; after calculating all the points After that, if , then the point Mark as noise points or dust points and remove them; Finally, all points marked as noise points are removed from the original point cloud data set P to obtain the denoised point cloud data set. .

3. A device for measuring the volume of a pilot pit for detecting roadbed compaction as claimed in claim 1, characterized in that: The data calculation module includes a surface calculation unit and a volume calculation unit; The surface calculation unit receives the preprocessed point cloud data, initializes the level set function to construct the distribution according to the point-to-point distance and direction rules of the point cloud data points in a specific initial area, and then evolves the level set function using a partial differential equation to obtain the zero isosurface of the level set function representing the surface of the test pit; The volume calculation unit calculates the normal vector of the gradient of the zero isosurface based on the zero isosurface calculated by the surface calculation unit and based on Gauss-Green's theorem, and then performs an integral operation to divide the test pit area into small cubic spaces, calculates the volume in the cubic space by the finite difference method, and sums them up to obtain the test pit volume.

4. A device for measuring the volume of a pilot pit for detecting roadbed compaction as claimed in claim 3, characterized in that: The surface calculation unit represents the surface of the test pit by calculating the zero isosurface in the level set function. The specific calculation process is as follows: Determine the initial region H containing the test pit. This region is a rectangular region larger than the minimum bounding box of the test pit. Initialize the level set function in region H. The level set function is a function defined in three-dimensional space. For each point in space , each function has a corresponding function Assume that after calculation, point ; For other points in region H , calculate Q to the nearest point cloud data point distance; ； If Q is In the direction of the normal vector pointing outside the region H, then ; if in the opposite direction, then ; By calculating all points in region H, the level set function is assigned to the entire region Corresponding initial values, a function distribution reflecting the space and surface conditions of the test pit is preliminarily constructed; Then, the level set function is analyzed by using the evolution method based on partial differential equations. Perform update iterations and finally obtain a level set function equal to 0 , the level set function at this time is the zero isosurface, that is, the surface of the test pit, that is, the test pit area The boundary of the test pit is expressed as .

5. A device for measuring the volume of a pilot pit for detecting roadbed compaction as claimed in claim 3, characterized in that: The volume calculation unit calculates the test pit volume V according to Gauss-Green's theorem: ； in is the position vector, It is the boundary of the test pit area , which is the unit external normal vector of the test pit surface, and S is used to indicate that the formula is on the test pit surface. The surface integral is performed on the surface, V represents the volume of the test pit, d is the differential element identifier in the integral operation, represents the gradient operator; Since the level set function The zero-value surface is the test pit surface , by calculating the zero isosurface of the level set function Finding the Gradient Get the unit external normal vector: ； but ； Then use the divergence theorem to convert the above surface integral into volume integral: ； The area Divide into small cubic spaces , whose side lengths are and Among them, a, b, and c are units Indexes of the x-axis, y-axis, and z-axis directions in three-dimensional space; Then for each unit , the center coordinates are , the integral term is calculated by discrete approximation based on the finite difference method The value of , and then calculate the volume within each unit ; ； Finally, the test pit volume V: ； That is, the volume of all units The sum is the volume of the test pit.

6. A device for measuring the volume of a pilot pit for detecting roadbed compaction as claimed in claim 1, characterized in that: The laser scanning module also includes a high-definition camera for further collecting images and information inside the test pit and transmitting them to the data display module for staff to compare and verify the data and images.

7. A device for measuring the volume of a pilot pit for detecting roadbed compaction as claimed in claim 1, characterized in that: The data display module also has a built-in wireless transmission unit, which can remotely transmit the displayed data and images to other terminal devices for convenient viewing by multiple people.

8. A measurement method applicable to the device for measuring the volume of a pilot pit for detecting roadbed compaction according to any one of claims 1 to 7, characterized in that: include: Step 1: Measurement preparation: Place the laser scanning module in the measurement device near the test pit to ensure that the laser scanning module can cover the entire test pit range; Step 2, data acquisition, start the laser scanning module, scan the test pit at multiple angles and multiple levels, and obtain a large amount of discrete point cloud data on the test pit surface, including point cloud data of the inner wall, bottom, and rough and irregular parts of the test pit. At the same time, the laser scanning module transmits the point cloud data to the data preprocessing module; Step 3, data preprocessing, the data preprocessing module receives the point cloud data, calculates and removes dust noise points according to the radius outlier filtering algorithm, and transmits the retained point cloud data to the data calculation module; Step 4: Determine the boundary of the test pit. The surface calculation unit of the data calculation module obtains the retained point cloud data, demarcates the initial area around the test pit, initializes the level set function, assigns an initial value by calculating the distance between the point and the point cloud data point and combining the direction condition, and obtains the zero isosurface of the level set function through the partial differential equation evolution to determine the surface of the test pit. Step 5, volume numerical calculation, the volume calculation unit first calculates the normal vector of the boundary gradient based on the determined test pit surface and with the help of Gauss-Green's theorem, converts the integral form and divides the calculation area into a cubic space, calculates the volume of the cubic space by the finite difference method and sums them up to obtain the total volume of the test pit; Step 6, result display, the data display module presents the boundary image, volume data and point cloud data image of the test pit area, and through the wireless transmission unit, the data and images can be received by the remote terminal to achieve shared viewing by multiple people.

Images