Device and method for automatically detecting compaction degree of broken pebble filler

Abstract

The invention relates to the technical field of crushed pebble filler compactness detection, and provides a crushed pebble filler compactness automatic detection device and method, the detection device comprises a support cylinder, a sand filling measurement assembly and a laser measurement assembly, the bottom of the support cylinder passes through a detection frame, and the bottom of a sand silo passes through the support cylinder and is provided with a sand filling pipe; the telescopic unit is arranged on the top wall of the supporting cylinder. A spiral blade is arranged at the output end of the driving piece. A discharge pipe is obliquely arranged at the discharge hole; the screening and weighing assembly is positioned on the detection frame; the laser measurement assembly is arranged at the bottom of the detection frame and located on one side of the supporting cylinder. The detection method comprises the steps of drilling, digging and collecting the broken pebble filler, screening and weighing, obtaining the volume of a dug hole through a laser measurement method, and evaluating the compaction degree of the broken pebble filler. The non-contact dynamic measurement of the volume of the test pit is combined with a weight distribution algorithm to integrate laser and sand filling data, so that the volume calculation precision is remarkably improved, and the problem of failure of a single method caused by gradation difference, rough surface or dust environment of the broken pebble filler is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of compactness detection of crushed pebble fillers, and particularly relates to an automatic detection device and a detection method for the compactness of crushed pebble fillers. Background Technique

[0002] When crushed pebbles are used as subgrade fillers, density monitoring is crucial for the stability and durability of the subgrade. Traditional methods such as the core cutter method and the sand replacement method are not applicable due to the irregular shape and large particle size of crushed pebbles. At the same time, they are inefficient, complex to operate, and greatly affected by human factors.

[0003] Traditional compactness detection relies on manual operation and is difficult to meet the requirements of efficient and accurate detection. Especially in crushed pebble fillers, it is difficult to guarantee the accuracy of the test pit volume measurement and density calculation.

[0004] Therefore, in view of the above problems, an automatic detection device and a detection method for the compactness of crushed pebble fillers are proposed to solve the above problems. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention develops an automatic detection device and a detection method for the compactness of crushed pebble fillers. The non-contact dynamic measurement of the test pit volume in the present invention combines the weight distribution algorithm to comprehensively process the laser and sand replacement data, significantly improving the accuracy of volume calculation and solving the problem of the failure of a single method caused by the grading difference, rough surface or dust environment of crushed pebble fillers.

[0006] The technical solution for the present invention to solve the technical problems is as follows: The present invention provides an automatic detection device for the compactness of crushed pebble fillers, which includes a detection frame, a drilling and excavation assembly, and a screening and weighing assembly. It also includes a support cylinder, a sand replacement measurement assembly, and a laser measurement assembly. The sand replacement measurement assembly includes a sand bin, a sand replacement pipe, and a weighing device I. The bottom of the support cylinder passes through the detection frame, and the top of the support cylinder is provided with the weighing device I. The sand bin is arranged on the weighing device I, and the sand replacement pipe is arranged at the bottom of the sand bin through the support cylinder; the drilling and excavation assembly includes a moving cylinder, a driving member, a spiral blade, and a telescopic unit. The telescopic unit is arranged on the top wall of the support cylinder, and the output end of the telescopic unit is connected to the moving cylinder. The moving cylinder is coaxially arranged inside the support cylinder. The driving member is arranged on the top wall of the moving cylinder, and the output end of the driving member is provided with the spiral blade. The bottom of the spiral blade passes through the bottom of the detection frame and is provided with a plurality of drill teeth; corresponding discharge ports are opened on the moving cylinder and the support cylinder, and a discharge pipe is obliquely arranged at the discharge port. The bottom of the discharge pipe is provided with the screening and weighing assembly, and the screening and weighing assembly is located on the detection frame; the laser measurement assembly is arranged at the bottom of the detection frame and on one side of the support cylinder.

[0007] As an optimization, the screening and weighing assembly includes a screening box and a weighing device II. The weighing device II is arranged on the detection frame, and the screening box is arranged above the weighing device II.

[0008] As an optimization, the driving part is a servo motor, the telescopic unit is a cylinder, a hand-held handle is arranged on the upper side of the detection frame, and a moving component is arranged at the bottom of the detection frame.

[0009] A method for detecting the compaction degree of crushed pebble filler, which is applicable to the automatic detection device for the compaction degree of crushed pebble filler described in any one of the above, includes the following steps. S1: Drill and collect the crushed pebble filler. Select the measured subgrade, place the detection device, the drilling component digs out the hole, and the sand filling measurement component fills the sand and filler. S2: Screen and weigh. The screening and weighing component screens and weighs the filler. S3: Obtain the volume of the dug hole by the laser measurement method. Including point cloud acquisition and distance calculation, point cloud preprocessing, three-dimensional model reconstruction and volume calculation. Then, the sand filling measurement component fills the sand and filler and calculates the volume. S4: Evaluate the compaction degree of the crushed pebble filler.

[0010] As an optimization, in the point cloud acquisition and distance calculation of S3, measure the distance from the measurement laser to a certain point on the surface of the pit. : Wherein, is the speed of light, is the laser round-trip time.

[0011] As an optimization, in the point cloud preprocessing of S3, first, statistically remove the outliers. Secondly, calculate the registration error from multiple perspectives. , Wherein, is the rotation matrix, is the translation vector, is the three-dimensional coordinate of the th point in the source point cloud. ; is the three-dimensional coordinate of the point corresponding to in the target point cloud, is the number of matching point pairs, [[ID=5⑦]]is the regularization coefficient, is the geometric error term, is the regularization term. Wherein, is the matrix trace operation, Then, calculate the surface roughness , Extract the local surface profile, calculate the reference line and the deviation value, and fit the reference line: , Deviation calculation, calculate the vertical deviation of each point from the reference line: Calculating roughness: Wherein, is the absolute deviation of each point.

[0012] As an optimization, in 3D model reconstruction and volume calculation, first determine the mesh quality, Wherein, is the inradius of the th triangle; is the circumradius; Secondly, use the voxelization integration method to calculate the volume. Divide the triangular mesh into cubic units of 0.1 mm 3 . Use the laser measurement method to obtain the volume of the excavated hole : Wherein, is the indicator function, is the volume of a single voxel.

[0013] As an optimization, in S4, first dry and weigh the excavated filler to obtain the mass of the filler and deduce the gradation, Calculate the volume of the sand poured in according to the mass of the poured sand and the density of the sand : Wherein, is the mass of the poured sand, is the density of the sand, Calculate the volume of the excavated pit, is 's weight, is 's weight, According to the result and compare it with 2.5%, and then assign different weights to and respectively and , When , , ; When , and the gradation is poor, and the proportion of fine materials is less than 10%, , ; When , and the surface roughness , , ; When and or the proportion of valid data in the laser point cloud is less than 85%, are solid and liquid particulate matters with a particle size equal to and less than 10 microns floating in the air, , ; Then, construct a test section to measure the density, Select the length of the test section to be constructed, conduct compaction threshold detection, and perform the detection every 20 m, recording the density changes under different compaction degrees and different gradations; Calculate the compaction energy index : Among them, is the equipment-material coupling coefficient, and the crushed pebbles are 2.5 - 4.5, is the amplitude of the roller, is the frequency of the roller, is the rolling speed of the roller, Calculate the attenuation coefficient and , , Among them, is the thickness of the compacted layer, m, is the proportion of the particle size of the excavated filler less than 5 mm, is the proportion of the particle size of the excavated filler less than 30 mm, Calculate the density measured in the constructed test section , Among them, is the gradation correction coefficient, , is the number of compaction passes, As the number of compaction passes increases, when the density measured in the constructed test section has an increase rate ≤ 0.5% for two consecutive passes, it can be regarded as reaching the maximum dry density. At this time, it is recorded as , , Among them, is the density measured in the normal section.

[0014] The effects provided in the invention content are only the effects of the embodiments, rather than all the effects of the invention. The above technical solutions have the following advantages or beneficial effects: 1. By integrating automated sand pouring measurement with high-precision 3D laser scanning technology, non-contact dynamic measurement of the test pit volume is achieved. Combining the weight distribution algorithm to synthesize laser and sand pouring data significantly improves the volume calculation accuracy, especially solving the problem of single method failure caused by grading differences, rough surfaces, or dusty environments of crushed pebble fillers. At the same time, this device can shorten the single-point detection time by more than 50%, reduce labor costs, and avoid fatigue errors, further ensuring data reliability under complex working conditions. 2. This device enables the compaction degree calculation to precisely match the actual material characteristics by real-time quantifying grading parameters and dynamically adjusting correction factors, and adjusts the parameters according to the actual situation, solving the systematic error caused by grading differences. Especially in complex working conditions dominated by coarse particles or with fluctuations in fine materials, it ensures that the detection results truly reflect the compactness state of the subgrade, providing a reliable scientific basis for construction. Description of the Drawings

[0015] The drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention.

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is the front view of the present invention; Figure 3 It is the structural diagram inside the support cylinder of the present invention.

[0017] In the figure, 1. Detection frame; 2. Support cylinder; 3. Sand bin; 4. Sand pouring pipe; 5. Moving cylinder; 6. Driving member; 7. Spiral blade; 8. Discharge port; 9. Discharge pipe; 10. Screening box; 11. Weighing device II; 12. Weighing device I; 13. Telescopic unit; 14. Control board; 15. Display screen; 16. Handheld handle; 17. Moving component; 18. Laser measurement component; 19. Drill teeth. Detailed Embodiments

[0018] To clearly illustrate the technical features of this solution, the present invention will be described in detail below through specific embodiments and in conjunction with its accompanying drawings. The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and settings of specific examples are described below. In addition, the present invention may repeat reference numerals and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. It should be noted that the components illustrated in the drawings are not necessarily drawn to scale. The present invention omits the description of well-known components, processing technologies and processes to avoid unnecessarily limiting the present invention. The orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0019] As Figures 1 to 3 shown, an automatic detection device for the compaction degree of crushed pebble filler includes a detection frame 1, a drilling and excavation assembly, and a screening and weighing assembly, and further includes a support cylinder 2, a sand filling and measuring assembly, and a laser measuring assembly 18. The sand filling and measuring assembly includes a sand bin 3, a sand filling pipe 4, and a first weighing device 12. The bottom of the support cylinder 2 passes through the detection frame 1 and is provided. The top of the support cylinder 2 is provided with the first weighing device 12, and the sand bin 3 is arranged on the first weighing device 12. The bottom of the sand bin 3 passes through the support cylinder 2 to set the sand filling pipe 4. Here, a control valve is provided at the connection between the sand filling pipe 4 and the sand bin 3, and the opening and closing of the sand filling pipe 4 are controlled by the controller. Here, the control component is a structure that can realize the opening and closing of the valve in the prior art and will not be elaborated too much. Setting the first weighing device 12 can calculate the mass of the sand filled in the pit, and then measure the volume of the sand filled in the pit. It first weighs the entire sand bin 3 and the mass of the sand in the bin, and then weighs the mass of the sand bin 3 and the remaining sand after the sand filling is completed, and the mass of the sand filled into the pit can be obtained. The drilling and excavation assembly includes a moving cylinder 5, a driving member 6, a spiral blade 7, and a telescopic unit 13. The telescopic unit 13 is arranged on the top wall of the support cylinder 2. The output end of the telescopic unit 13 is connected to the moving cylinder 5. The moving cylinder 5 is coaxially arranged inside the support cylinder 2. The driving member 6 is arranged on the top wall of the moving cylinder 5. The output end of the driving member 6 is provided with the spiral blade 7, and the bottom of the spiral blade 7 penetrates through the bottom of the detection frame 1 and is arranged there; Feeding ports 8 are correspondingly opened on the moving cylinder 5 and the support cylinder 2. A discharge pipe 9 is inclinedly arranged at the feeding port 8. A screening and weighing assembly is arranged at the bottom of the discharge pipe 9. The screening and weighing assembly is located on the detection frame 1; After the drilling and excavation assembly excavates the crushed pebble filler, the crushed pebble filler enters the screening and weighing assembly through the feeding port 8 and the discharge pipe 9; The laser measurement assembly 18 is arranged at the bottom of the detection frame 1 and is located on one side of the support cylinder 2. The laser measurement assembly 18 emits a highly stable laser beam, providing a light source basis for measurement. Here, the laser measurement assembly 18 can be mechanically controlled to adjust the angle of laser scanning and the position movement. The specific mechanical structure for realizing the angle adjustment and position movement of the laser measurement assembly 18 is prior art and will not be elaborated here.

[0020] In this embodiment, the screening and weighing assembly includes a screening box 10 and a weighing device II 11. The weighing device II 11 is arranged on the detection frame 1, and the screening box 10 is arranged above the weighing device II 11. Here, the screening box 10 is a drawer-type sieve body. Two sieve meshes are arranged inside the screening box 10 to divide the screening box 10 into three layers. The two sieve meshes are sieve meshes with 10 mm sieve holes and 5 mm sieve holes from top to bottom. The weighing device II 11 can weigh the crushed pebbles entering the screening box 10. When screening, a vibration motor can be set to drive the sieve mesh to vibrate, so as to screen the crushed pebble material. Driving the sieve mesh to vibrate by the vibration motor is prior art and will not be elaborated here. The weighing device II 11 and the weighing device I 12 are prior structures and will not be elaborated here.

[0021] In this embodiment, the driving member 6 is a servo motor, the telescopic unit 13 is a cylinder, a handheld handle 16 is arranged on the upper side of the detection frame 1, and a moving assembly 17 is arranged at the bottom of the detection frame 1. The moving assembly 17 can be a universal wheel. A control board 14 and a display screen 15 are also arranged on the detection frame 1. A switch I and a switch II respectively electrically connected to the driving member 6 and the telescopic unit 13 are arranged on the control board 14. The display screen 15 is electrically connected to the weighing device II 11 and the weighing device I 12 to display the weighing result.

[0022] A method for detecting the compaction degree of crushed pebble filler, applicable to the automatic detection device for the compaction degree of crushed pebble filler described in any one of the above, includes the following steps, S1: Drill and excavate to collect the crushed pebble filler, Select a measurement subgrade, place the detection device, the drilling and excavation assembly excavates a hole, and the sand filling measurement assembly fills the sand filler, S2: Screening and weighing, The screening and weighing assembly screens and weighs the filler. S3: Obtaining the volume of the excavated hole by laser measurement method, Including point cloud acquisition and distance calculation, point cloud preprocessing, 3D model reconstruction and volume calculation. Then, the sand filling measurement assembly fills the sand and calculates the volume. S4: Evaluation of the compaction degree of the crushed pebble filler.

[0023] In this embodiment, in the point cloud acquisition and distance calculation of S3, after the laser is emitted to the surface of the pit and reflected, the device records the round-trip time. , and uses the speed of light to calculate the single-point distance , and combines the scanning angle to generate the three-dimensional coordinates of each point on the surface of the pit. , forming the initial point cloud. Measure the distance from the laser to a certain point on the surface of the pit. : Among them, is the speed of light, is the laser round-trip time.

[0024] In this embodiment, in the point cloud preprocessing of S3, first, statistical outlier rejection. After the point cloud is generated, the neighborhood radius and standard deviation multiple are input, and the three-dimensional distance (not the original laser ranging value) between each point and other points in its neighborhood is calculated, and the mean and standard deviation of these distance values are statistically calculated. If the deviation of a certain point distance from the neighborhood average is greater than the product of the standard deviation multiple and the standard deviation, then this point is removed. Secondly, calculate the registration error from multiple perspectives. Align the point cloud in the local coordinate system to the global coordinate system. Through iterative optimization, the qualified point cloud will be unified into the same coordinate system for surface roughness calculation and 3D reconstruction. , Among them, is the rotation matrix for aligning the coordinate systems of two point clouds; is the translation vector for adjusting the position offset of the point cloud; is the three-dimensional coordinate of the th point in the source point cloud (the point cloud from a certain perspective); ; is the three-dimensional coordinate of the corresponding point in the target point cloud (the point cloud from another perspective) to ; is the number of matching point pairs (i.e., the number of points with established corresponding relationships in the two point clouds); is the regularization coefficient, which is used to constrain the orthogonality of the rotation matrix ; is the geometric error term, which represents the sum of the squares of the position deviations of the matching point pairs and directly reflects the registration accuracy. The registration error is the result of taking the square root of its mean, that is ; is the regularization term, where is the matrix trace operation (Trace), which represents the sum of the diagonal elements and is used to prevent excessive deviation from orthogonality; Input parameters: Point cloud coordinates from different perspectives (local coordinate system) and (global coordinate system), regularization coefficient ; Calculation process: Through iterative optimization, find the rotation matrix and the translation vector to align the two point clouds; the regularization term prevents the rotation matrix from being overly distorted; Output result: Registration error ≤ 0.2 mm; Purpose: To unify the point clouds scanned from multiple perspectives into the same coordinate system and reconstruct a complete pit model.

[0025] Then, calculate the surface roughness , Extract the local surface profile, calculate the baseline and the deviation value, baseline fitting: , use the least squares method to fit the trend line (polynomial fitting or straight line) of the profile points, Deviation calculation, calculate the vertical deviation of each point from the baseline: Calculate the roughness: where is the absolute deviation of each point (unit: mm).

[0026] In this embodiment, in the three-dimensional model reconstruction and volume calculation, first determine the mesh quality, avoid volume calculation errors caused by narrow triangular patches, and ensure the model accuracy: where is the inradius of the subscript triangle; is the circumradius; When, determine that the mesh is qualified, otherwise re-mesh; Secondly, use the voxelization integration method to calculate the volume, divide the triangular mesh into 0.1 mm 3The cubic unit (voxel) Obtain the volume of the excavated hole by laser measurement :[[]] Wherein, Is an indicator function (1 when the voxel center is in the pit, otherwise 0), Is the number of internal voxels, Is the volume of a single voxel.

[0027] In this embodiment, in S4, first dry and weigh the excavated filler to obtain the mass of the filler and deduce the gradation, Calculate the volume of the sand poured in according to the mass of the sand poured in and the density of the sand :[[]] Wherein, Is the mass of the sand poured in, Is the density of the sand, Calculate the volume of the excavated pit, Is The weight of, Is The weight of, According to The result of is compared with 2.5%, and then And Are given different weights And , When , the difference is small, and equal weighting is used, , ; When , and the gradation is poor, and the proportion of fine materials is less than 10%, too little fine materials will cause the sand pouring method to easily overestimate the volume (the sand flows into the gap), so the laser weight is increased, , ; When , and the surface roughness , the roughness is high, and the unevenness of the inner wall of the pit may affect the accuracy of laser measurement, , ; When , and Or the proportion of valid laser point cloud data is less than 85%, Is solid and liquid particulate matter floating in the air with a particle size equal to and less than 10 microns. Due to dust or strong light, the reliability of laser scanning is reduced, and the sand pouring method is preferably relied on, , ; Then, a test section is constructed to measure the density. Select the length of the test section to be constructed and conduct compaction threshold detection. Detection is carried out every 20m, and record the density changes under different compaction degrees and different gradations. Calculate the compaction energy index : Wherein, is the equipment-material coupling coefficient, and the crushed pebbles are 2.5 - 4.5, is the amplitude of the roller, is the frequency of the roller, is the rolling speed of the roller, Calculate the attenuation coefficient and , , Wherein, is the thickness of the compacted layer, m, is the proportion of the excavated filler with a particle size less than 5mm, is the proportion of the excavated filler with a particle size less than 30mm, Calculate the density measured in the constructed test section , Wherein, is the gradation correction coefficient, , when the fine material content increases by 5% on the basis of 10%, k increases by 0.03, is the number of compaction passes, As the number of compaction passes increases, when the density measured in the constructed test section has an increase rate ≤ 0.5% for two consecutive passes, it can be regarded as reaching the maximum dry density. At this time, record it as , , Wherein, is the density measured in the normal section.

[0028] This device is a systematic optimization and innovation of traditional detection methods. For traditional sand replacement method and core cutter method, due to the irregular shape, large particle size and complex voids of crushed pebbles, the measurement error of the test pit volume is significant, and it relies on manual operation with low efficiency and is easily affected by human experience. This device realizes non-contact dynamic measurement of the test pit volume by integrating automated sand replacement measurement and high-precision three-dimensional laser scanning technology, combines the laser and sand replacement data with a weight distribution algorithm, significantly improves the volume calculation accuracy, and especially solves the problem of single method failure caused by gradation differences, rough surface or dust environment of crushed pebble fillers. At the same time, this device can shorten the single-point detection time by more than 50%, reduce labor costs and avoid fatigue errors, further ensuring data reliability under complex working conditions. This device makes the compaction degree calculation accurately match the actual material characteristics by real-time quantifying the gradation parameters and dynamically adjusting the correction coefficient, adjusts the parameters according to the actual situation, solves the systematic error caused by gradation differences, and especially ensures that the detection results truly reflect the subgrade compaction state under complex working conditions dominated by coarse particles or fluctuating fine materials, providing a reliable scientific basis for construction.

[0029] Calculation process: Mass of sand filled is 19199.47 g, is 1.52 g / cm 3 (Coarse sand (1.0 - 2.36 mm) prevents sand leakage from the gaps between large crushed stones) Calculate the volume of sand filled according to the mass of sand filled and the density of sand : Control example: Calculate the qualified rate of compaction degree of crushed pebble fillers by traditional sand replacement method. First, dry and weigh the excavated fillers. , Volume of the excavated pit , , Calculate the dry density , , Calculate the compaction degree, where the maximum dry density determined by laboratory standard compaction test , , .

[0030] The qualified rate of compaction degree of crushed pebble fillers calculated by this device: Determine the maximum dry density through the test section , First, obtain the volume of the excavated hole by laser measurement method , , is 126940000, and obtain , Then, the volume of the sand filled is obtained by the sand replacement method : , , so , , , Take 3.5, , , , Obtain , Take 20%, Take 60%, , Obtain , , Finally, When taking 1 - 6 in sequence, the obtained density is shown in Table 1: Table 1 Relationship between compaction passes and density The volume used in the calculation here is the volume corresponding to 6 compaction passes. The decrease in volume as the number of compaction passes increases is not considered, so the density result is on the high side. However, it can still be seen that as the number of compaction passes increases, the correction trend of the formula for the result is correct; When is 6, the density measured in the test section for two consecutive passes increases by ≤ 0.5%, which is considered to have reached the maximum dry density. Therefore, , The density of the normal test section to be measured is denoted as , Example 1: After the roller compacts 3 times at point P1 on the normal section, the compaction degree is measured with this device (for the convenience of calculation in this example, the gradation information of a certain point tested on the normal section is the same as that of the test section). , , , , , , , , , , , therefore, , , , , , , , , further compaction is still required. When the number of compaction passes is 6, ; After the roller compacts 3 times at point P2 on the normal section, the volume is the volume corresponding to 3 compaction passes, and the proportion of particles with a particle size greater than 30 mm is reduced in the gradation. Take 20%, Take 50%, , , , , , , , , , , , therefore, , , , , , , , It can be seen that , this is because the gradation of has more coarse particles compared to the gradation of After the roller compacts 3 times at point P3 on the normal section, the volume is the volume corresponding to 3 compaction passes, and the proportion of particles with a particle size less than 5 mm is reduced in the gradation. Take 15%, Take 60%, , , , , , , , , , , , therefore, , , , , , , , It can be seen that , is equivalent to , which is because has insufficient fine materials in its gradation compared to 's gradation, resulting in insufficient filling and the remaining voids reducing the density.

[0031] Although the specific embodiments of the invention have been described above in conjunction with the accompanying drawings, it is not a limitation on the protection scope of the present invention. Based on the technical solutions of the present invention, various modifications or deformations that can be made by those skilled in the art without creative efforts are still within the protection scope of the present invention.

Claims

1. An automatic detection device for the compaction degree of crushed pebble filler, comprising a detection frame (1), a drilling and excavation component, and a screening and weighing component, characterized in that: It also includes a support cylinder (2), a sand filling measurement component, and a laser measurement component (18). The sand filling measurement component includes a sand bin (3), a sand filling pipe (4), and a first weigher (12). The bottom of the support cylinder (2) passes through the detection frame (1). The first weigher (12) is arranged at the top of the support cylinder (2). The sand bin (3) is arranged on the first weigher (12). The sand filling pipe (4) is arranged at the bottom of the sand bin (3) and passes through the support cylinder (2). The drilling and excavation component includes a moving cylinder (5), a driving member (6), a spiral blade (7), and a telescopic unit (13). The telescopic unit (13) is arranged on the top wall of the support cylinder (2). The output end of the telescopic unit (13) is connected to the moving cylinder (5). The moving cylinder (5) is coaxially arranged inside the support cylinder (2). The driving member (6) is arranged on the top wall of the moving cylinder (5). The output end of the driving member (6) is provided with the spiral blade (7). The bottom of the spiral blade (7) passes through the bottom of the detection frame (1) and is provided with a plurality of drill teeth (19). Corresponding discharge ports (8) are opened on the moving cylinder (5) and the support cylinder (2). An inclined discharge pipe (9) is arranged at the discharge port (8). The bottom of the discharge pipe (9) is provided with a screening and weighing component, and the screening and weighing component is located on the detection frame (1). The laser measurement component (18) is arranged at the bottom of the detection frame (1) and is located on one side of the support cylinder (2).

2. The automatic detection device for the compaction degree of crushed pebble filler according to claim 1, wherein: The screening and weighing component includes a screening box (10) and a second weigher (11). The second weigher (11) is arranged on the detection frame (1). The screening box (10) is arranged above the second weigher (11).

3. The automatic detection device for the compaction degree of broken pebble filler according to claim 1 or 2, characterized in that: The driving member (6) is a servo motor, the telescopic unit (13) is a cylinder, a hand-held handle (16) is arranged on the upper side of the detection frame (1), and a moving component (17) is arranged at the bottom of the detection frame (1).

4. A method for detecting the compaction degree of crushed pebble filler, which is applicable to the automatic detecting device for the compaction degree of crushed pebble filler described in any one of the above claims 1-3, is characterized in that: It includes the following steps S1: Drill and excavate to collect crushed pebble fillers, Select the subgrade to be measured, place the detection device, the drilling and excavation component digs out holes, and the sand filling measurement component fills the fillers with sand. S2: Screen and weigh, The screening and weighing component screens and weighs the fillers. S3: Use the laser measurement method to obtain the volume of the dug hole, including point cloud acquisition and distance calculation, point cloud preprocessing, 3D model reconstruction and volume calculation. S4: Evaluate the compactness of the crushed pebble fillers.

5. The compaction degree detection method of the broken pebble filler according to claim 4 is characterized in that in S3 point cloud acquisition and distance calculation, the distance from the measurement laser to a certain point on the surface of the pit is measured : Among them, is the speed of light, is the round-trip time of the laser.

6. The method for detecting the compactness of crushed pebble fillers according to claim 5, characterized in that: in the point cloud preprocessing of S3, first, statistical outliers are removed. Secondly, the registration error is calculated from multiple perspectives. , Among them, is a rotation matrix, is a translation vector, is the three-dimensional coordinates of the -th point in the source point cloud ; is the three-dimensional coordinates of the point in the target point cloud corresponding to , is the number of matching point pairs, is a regularization coefficient, is a geometric error term, is a regularization term, where is a matrix trace operation, Then, calculate the surface roughness , Extract the local surface profile, calculate the reference line and deviation value, and fit the reference line: , Deviation calculation, calculating the vertical deviation of each point from the reference line: Calculated roughness: Among them, is the absolute deviation of each point.

7. The method for detecting the compactness of crushed pebble fillers according to claim 6, characterized in that: in the 3D model reconstruction and volume calculation, first, the mesh quality is determined. Among them, is the inradius of the th triangle; is the radius of the circumscribed circle; Secondly, the volume is calculated by voxelization integration method, and the triangular mesh is divided into cube cells with a size of 0.1 mm 3 . Volume of the excavated hole obtained by laser measurement : Among them, is an indicator function, is the volume of a single voxel.

8. The method for detecting the compactness of crushed pebble fillers according to claim 7, characterized in that: in S4, first, the dug fillers are dried and weighed to obtain the mass of the fillers and the gradation is deduced. Calculate the volume of the sand filled in according to the mass of the filled sand and the density of the sand : Among them, is the mass of the filled sand, is the density of the sand, Calculate the volume of the excavated hole, is the weight of, is the weight of, According to the result is compared with 2.5%, and then different weights and are assigned respectively and , When then , ; When and the gradation is poor, with the proportion of fine materials less than 10%, , ; When , and the surface roughness is , ; When and or the proportion of valid laser point cloud data is less than 85%, are solid and liquid particulate matters floating in the air with a particle size equal to and less than 10 microns, , ; Then, a test section is built to measure the density. Select the length of the test section to be built, conduct the compactness threshold detection, detect once every 20m, and record the density change under different compactness and different gradations. Calculating the Compaction Energy Index : Among them, is the equipment-material coupling coefficient, and the crushed pebbles are 2.5 - 4.5, is the amplitude of the roller, is the frequency of the roller, is the rolling speed of the roller, Calculate the attenuation coefficient and , , Among them, is the thickness of the compacted layer, in m, is the proportion of the excavated fill with a particle size less than 5 mm, is the proportion of the excavated fill with a particle size less than 30 mm. Calculate the density measured in the construction test section , Among them, is the gradation correction coefficient, , is the number of compaction passes, As the number of compaction passes increases, when the density measured during the construction of the test section shows an increase rate of ≤ 0.5% for two consecutive times, it can be regarded as reaching the maximum dry density. At this time, it is recorded as , ， Among them, is the density measured on the normal road section.

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