A modular apparatus for identifying and sizing differently morphologically characterized aggregate particles

Abstract

A kind of modular equipment for identifying and screening different morphological characteristic aggregate particles, including material conveying system, screening system, transmission system, 3D laser scanning system, image acquisition and processing system, aggregate screening system, screening system is first screened, aggregate of different particle size is classified, the aggregate particles of same particle size are batch conveyed in combination with material conveying system and transmission system, secondly, 3D laser scanning system and image acquisition and processing system are used to obtain the morphological characteristic parameters of aggregate particles, finally, aggregate screening system puts the aggregate particles of different shapes of same particle size into different storage tanks.The 3D laser scanning system, image acquisition and processing system and aggregate screening system of the present application each have two sets, twice identification, screening aggregate particles of different shapes, for asphalt mixture pavement construction site, can improve the efficiency and precision of screening aggregate particles of different shapes, to improve the efficiency and quality of asphalt pavement construction.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of highway engineering, and relates to a modular equipment for identifying and screening aggregate particles with different morphological characteristics. BACKGROUND

[0002] In the construction process of highway asphalt pavement, the content of needle-like and broken particles in the coarse aggregate of the mixture is required to be relatively strict. The shape characteristics and gradation of aggregate particles have an important influence on the performance and service life of asphalt mixture. According to the highway asphalt pavement construction technical specification, the method for determining the proportion of needle-like and broken particles in the aggregate is to measure, judge, count and calculate the content of needle-like and broken particles in the coarse aggregate particles by using a vernier caliper. This method has low efficiency and accuracy in counting the proportion of different shaped particles in the aggregate, and cannot quickly and accurately calculate the percentage of different shaped and sized particles in the road aggregate.

[0003] Based on the difficulties encountered in determining the proportion of different shaped particles in the construction process of highway asphalt pavement, the present application proposes a modular equipment for identifying and screening aggregate particles with different morphological characteristics, starting from the morphological characteristics and particle size distribution of the mixture aggregate. SUMMARY

[0004] The present application proposes a modular equipment for identifying and screening aggregate particles with different morphological characteristics, which is used in the construction site of asphalt pavement to identify and screen particles with different particle sizes and shapes in the aggregate field, and aims to quickly and accurately classify and calculate the particles with different particle sizes and shapes in the aggregate and their percentage in the aggregate.

[0005] The present application solves the technical problem by adopting the following technical solution:

[0006] A modular equipment for identifying and screening aggregate particles with different morphological characteristics, comprising a feeding system, a screening system, a transmission system, a 3D laser scanning system, an image acquisition and processing system, and an aggregate screening system. The feeding system comprises an aggregate bin and a conveyor belt a. The screening system comprises a sleeve screen, a vibration table and a feeding bin. The transmission system comprises a sensor and a conveyor track. The 3D laser scanning system comprises a 3D laser scanner, a laser receiving target and a support frame. The image acquisition and processing system comprises an image acquisition device and a support frame b. The aggregate screening system comprises a sorter and a storage bin. The feeding system delivers raw aggregate to the screening system, which delivers aggregate particles of different grades to the transmission system through the feeding bin. The conveyor track of the transmission system delivers aggregate particles to the 3D laser scanning system, the image acquisition and processing system and the aggregate screening system for constructing a three-dimensional model of the aggregate particles, image acquisition and processing, screening aggregate particles with different shape characteristics, and feeding them into different storage bins.

[0007] The 3D laser scanning system comprises a 3D laser scanner, a laser receiving target, and a support frame a. The 3D laser scanner is located on the support frame a and can be moved and rotated to adjust the position through a conveyor belt on the support frame a, so as to construct a three-dimensional model of aggregate, for later analysis and processing.

[0008] The 3D laser scanner constructs a three-dimensional model of different aggregate particles, for detecting and calculating the length, width, and thickness of different shape aggregate particles. The length of the aggregate particle is the longest axis L in the constructed three-dimensional model, the width is the longest axis perpendicular to the direction of the length, which is the second longest axis W in the three-dimensional model, and the thickness is the longest axis perpendicular to the direction of the length and width, which is the shortest axis T in the three-dimensional model.

[0009] The detection and calculation of the length, width, and thickness of different shape aggregate particles are used to determine the needle and sheet coefficients of the aggregate particles. When the aggregate particle L / W≥3, it is defined as a needle-shaped particle, and when the aggregate particle W / T≥3, it is defined as a sheet-shaped particle.

[0010] The image acquisition and processing system comprises an image acquisition device and a support frame b. The image acquisition device is located on the support frame b and can be moved and rotated to adjust the position through a conveyor belt and a support frame on the support frame b, so as to obtain the cross section of the aggregate particle at different angles and calculate the cross-sectional area of different aggregate particles.

[0011] The three-dimensional model of different aggregate particles constructed by the 3D laser scanner is used to detect and calculate the projected area of the aggregate particle fracture surface. The constructed three-dimensional model is processed by triangular meshing, simplified model construction, and edge detection processing to detect the edges of the aggregate particle fracture surface, obtain and calculate the maximum area of the projection of the fracture surface contour at different angles, and record it as X i (i = 1, 2, 3,..., n). The image acquisition device calculates the maximum cross-sectional area A of the same aggregate particle obtained at different angles. When the aggregate particle X i / A≥1 / 4, it is defined as a broken particle. For the same aggregate particle, the number of fracture surfaces meeting the requirement of X i / A≥1 / 4 is recorded as a prerequisite for the sorter to screen aggregate particles.

[0012] The sensor under the conveying caterpillar records the position of the aggregate particles, combined with a 3D laser scanning system, which is used to capture the position information of the aggregate particles on the conveying caterpillar at different time periods, and combined with an aggregate screening system, which screens aggregate particles of different shapes. The aggregate screening system includes a sorter and a storage box, the sorter screens out needle-shaped and broken-shaped particles and puts them into different storage boxes; in the screening process, first, needle-shaped and sheet-shaped particles are screened out and put into storage boxes c and a respectively, then aggregate particles without or with one required broken surface are screened out and put into storage boxes d and b respectively, and finally, the conveying caterpillar carries aggregate particles with two or more than two required broken surfaces to the storage box e. In the whole process of identifying and screening aggregate particles, there are two sets of 3D laser scanning systems, image acquisition and processing systems and aggregate screening systems respectively, and there are eight sorters in total, which are used for secondary identification and screening of aggregate particles to improve the efficiency and accuracy of screening.

[0013] Compared with the prior art, the beneficial effects of the present application are:

[0014] 1. The modular screening equipment of the present application adopts a vibration table combined with a standard nest screen to screen aggregate particles, and different particle sizes of aggregate particles are discharged into different specifications of the nest screen, and then the same particle size aggregate particles are batch transported, selected and classified according to different shapes, so as to improve the accuracy and efficiency of the 3D laser scanning, image acquisition and processing system in identifying and classifying different shaped particles.

[0015] 2. The modular screening equipment of the present application adopts a 3D laser scanning system to batch construct a three-dimensional model of aggregate particles, calculate the needle and sheet coefficient of different aggregate particles, and use a sorter to batch select aggregate particles with a needle and sheet coefficient greater than or equal to 3, so as to improve the efficiency and accuracy of screening needle and sheet aggregate particles.

[0016] 3. The modular screening equipment of the present application adopts image processing technology to batch construct a three-dimensional model of aggregate particles, accurately calculate the number of required broken surfaces contained in the aggregate particles, and use a sorter to batch select and classify aggregate particles with different numbers of required broken surfaces, so as to improve the efficiency and accuracy of screening different types of broken aggregate particles, facilitate the design of asphalt pavement construction, and improve the engineering quality of paving asphalt pavement.

[0017] 4. The modular screening equipment of the present application performs secondary scanning and constructs a three-dimensional model of aggregate particles, and performs secondary screening of needle and sheet particles and broken particles, so as to improve the efficiency and accuracy of identifying and classifying aggregate particles. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The present application is a schematic diagram of different systems of the modular screening equipment;

[0019] Figure 2Schematic diagram of the feeding system of the modular screening equipment of the present application and the screening system;

[0020] Figure 3 3D laser scanning system of the modular screening equipment of the present application;

[0021] Figure 4 Schematic diagram of the image acquisition and processing system of the modular screening equipment of the present application;

[0022] Figure 5 Front view of the conveying system of the modular screening equipment of the present application;

[0023] Figure 6 Rear view of the conveying system of the modular screening equipment of the present application;

[0024] Figure 7 Schematic diagram of the storage system a of the modular screening equipment of the present application;

[0025] Figure 8 Schematic diagram of the storage system b of the modular screening equipment of the present application;

[0026] Figure 9 Schematic diagram of the screen sleeve of the modular screening equipment of the present application;

[0027] Figure 10 Two-dimensional image of the aggregate particles acquired by the image acquisition and processing system of the present application;

[0028] Figure 11 Two-dimensional image of the aggregate particles processed by the image acquisition and processing system of the present application;

[0029] Figure 12 Three-dimensional aggregate particle model processed by the 3D laser scanning system of the present application;

[0030] Figure 13 Three-dimensional aggregate particle model processed by the 3D laser scanning system of the present application;

[0031] Figure 14 Three-dimensional model of the aggregate particles detected by the 3D laser scanning system of the present application.

[0032] In the figure, 1-feeding system, 2-screening system, 3-transmission system, 4-3D laser scanning system a, 5-image acquisition and processing system a, 6-3D laser scanning system b, 7-image acquisition and processing system b, 8-aggregate screening system, 9-set screen, 10-feeding bin, 11-conveyor belt a, 12-aggregate bin, 13-vibrating table, 14-3D laser scanner, 15-support frame a, 16-conveyor belt b, 17-laser receiving target, 18-image acquisition device, 19-support frame b, 20-conveyor belt c, 21-sorter a, 22-sorter b, 23-sorter c, 24-sorter d, 25-sensor, 26-transmission crawler, 27-storage system a, 28 -Storage system b, 29-Storage system c, 30-Storage box a, 31-Storage box b, 32-Storage box c, 33-Storage box d, 34-Discharger, 35-Discharge port, 36-Storage box e, 37-Discharge port b, 38-Discharger b, 39-Discharger c, 40-Spherical joint, 41-Aggregate valve, 42-Crushing surface 1, 43-Crushing surface 2, 44-Crushing surface 3, 45-Crushing surface 4, 46-Crushing surface 5, 47-Edge detection of crushing surface 1, 48-Edge detection of crushing surface 2, 49-Edge detection of crushing surface 3, 50-Edge detection of crushing surface 4, 51-Edge detection of crushing surface 5, 52-Length of aggregate particles, 53-Width of aggregate particles, 54-Thickness of aggregate particles. DETAILED DESCRIPTION

[0033] The following is combined with Figures 1 to 14 , Tables 1 to 2 and the technical solution further illustrate the present invention in detail.

[0034] like Figure 1 As shown, the present invention comprises eight systems: feeding system 1, screening system 2, transmission system 3, 4-3D laser scanning system a, 5-image acquisition and processing system a, 6-3D laser scanning system b, 7-image acquisition and processing system b, and aggregate screening system 8. The working principle of the present invention is explained below with an example.

[0035] like Figure 2 、 9 As shown, the feed system 1 and screening system 2 of the modular screening equipment of the present invention include five working devices: a screen 9, a feed bin 10, a conveyor belt 11 a, an aggregate bin 12, and a vibrating table 13. Crushed aggregate particles are transported to the screen 9 via the aggregate bin 12 and the conveyor belt 11 a. The vibrating table 13 vibrates the screen 9 to screen the aggregate particles. After the aggregate particles are screened, the aggregate valve 41 is opened, and the discharger 39 c discharges aggregate particles of a certain particle size into the feed bin 10. The discharger c is equipped with a spherical joint 40, which allows the discharger 39 to move flexibly within the screen 9, facilitating the discharge of aggregate.

[0036] As Figure 3 shown, the 3D laser scanning system of the modular screening device of the present application can scan and construct a three-dimensional model of the aggregate, and perform triangular mesh processing to simplify the three-dimensional model of the aggregate particles, as Figure 14 shown. Among all the constructed three-dimensional models, the distance between two points of different meshes of the aggregate particles is detected, and the two points with the largest distance are determined as the longest axis L of the aggregate particles. The aggregate is vertically cut n times along the longest axis L of the aggregate particles, and the smallest circumscribed rectangle of the cut section is searched and constructed, and the length of the largest circumscribed rectangle is taken as the second longest axis W of the aggregate particles, and the width is taken as the shortest axis T of the aggregate particles. Finally, the smallest circumscribed cuboid of the three-dimensional model of the aggregate particles is constructed, as Figure 14 shown. The length, width and thickness of the aggregate particles of different shapes are detected and calculated, which are used to determine the needle and flake coefficients of the aggregate particles. When L / W≥3, the aggregate particles are defined as needle-shaped particles, and when W / T≥3, the aggregate particles are defined as flake-shaped particles.

[0037] As Figure 5 , 6 shown, the transmission system of the modular screening device of the present application includes sensors 25 and a conveying belt 26, which can transport the aggregate particles to the areas where the 4-3D laser scanning system a and the 5-aggregate screening system a work. Under different areas of the conveying belt 26, multiple sensors 25 are arranged, which cooperate with the 4-3D laser scanning system a to record the positions of the aggregate particles at different times. The 4-3D laser scanning system a includes a 3D laser scanner 14, a 15-supporting frame a, a 16-conveying belt b, and a laser receiving target 17. The 3D laser scanner 14 scans the aggregate particles in multiple directions through the 15-supporting frame a and the 16-conveying belt b, and the laser receiving target 17 receives the digital information obtained by the 3D laser scanner 14 to construct a three-dimensional model of the aggregate particles. The position information of the aggregate particles is obtained by combining the sensors 25, and the spatial position of the aggregate particles with a needle and flake coefficient value greater than or equal to "3" is captured. The aggregate screening system 8 includes sorters and storage bins. The sorters 21, 23, 22, and 24 cooperate with the 4-3D laser scanning system a, the sensors 25, and the conveying belt 26 to respectively put needle-shaped particles into the 32-storage bin c, flake-shaped particles into the 30-storage bin a, aggregate particles without a required crushing surface into the 33-storage bin d, and aggregate particles with one required crushing surface into the 31-storage bin b. On the transmission system, there are two 3D laser scanning systems, two image acquisition and processing systems, and eight sorters, which can twice identify and classify the aggregate particles. After the sorters put the needle and flake-shaped particles, and the aggregate particles without or with one required crushing surface into different storage bins, the conveying belt 26 transports the aggregate particles with two or more required crushing surfaces to the 29-storage bin e.

[0038] As Figure 4 shown, the image acquisition and processing system of the modular screening device of the present application can scan and record the cross sections of aggregate particles at different angles, as Figure 10 shown. The recorded cross sections of different aggregate particles are subjected to binary processing, edge detection of the cross sections of aggregate particles, and calculation of the cross-sectional areas of aggregate particles. For the same aggregate particle, the image acquisition device 18 can move along with the conveyor belt c and the support frame b, and the cross-sectional areas obtained at different angles are recorded, and the largest cross-sectional area A of the aggregate particle is recorded. The 3D laser scanning system scans and constructs a three-dimensional model of the aggregate particle, adjusts the areas and curvatures of different detection regions, and edge detects the positions and contours of different broken surfaces of the aggregate particle, as Figure 12 、 13 shown. For the same aggregate particle, the positions and contours of different broken surfaces are projected and calculated to obtain the largest projected area of the contour of each broken surface, which is taken as the projected area X i of the broken surface of the aggregate particle. When X i / A≥1 / 4, the aggregate particle is determined to be a broken particle. For the same aggregate particle, the number of broken surfaces meeting the requirement of X i / A≥1 / 4 is recorded as a prerequisite for the screening of aggregate particles by the sorter. The 4-3D laser scanning system a and the 5-image acquisition and processing system a, in combination with the sensor 25, are used to record the positions of needle-shaped, flaky, and aggregate particles without or with one or more than two broken surfaces meeting the requirement on the conveyor belt 26. The 6-3D laser scanning system b and the 7-image acquisition and processing system b have the same functions as the 4-3D laser scanning system a and the 5-image acquisition and processing system a, and can be used to identify and classify the shapes of aggregate particles twice, in combination with the four sorters located behind, to select aggregate particles twice to improve the efficiency and accuracy of identification and classification of aggregate particles.

[0039] As Figure 7 、 8 shown, each storage tank is provided with a discharge port 35 and a discharger 34. After the sorter pours aggregate particles with different morphological characteristics into the storage tank, the storage port 35 is opened, and the discharger 34 discharges the aggregate particles in the storage tank. The 27-storage bin a, the 28-storage bin b, and the 29-storage bin c have a certain height, which facilitates the transportation of aggregate particles in different storage tanks by the transport vehicle. As Figure 2 、 9 shown, the vibration table 13 and the vibrating screen 9 complete the screening of aggregate particles. Each screen is provided with a 39-discharger c and an aggregate valve 41. After the screening of aggregate particles is completed, the aggregate valve 41 is opened, and the discharger 40 discharges the aggregate particles, which are transported to the conveyor belt 26 through the conveying bin 10.

[0040] The present application determines the content of acicular and flaky particles and the number of broken surfaces of broken particles in the aggregate of the mixture, and refers to the Highway Engineering Aggregate Test Specification (JTG E42-2005). In addition, the Highway Asphalt Pavement Construction Technical Specification (JTG F40-2004) provides the content and requirements of acicular and flaky particles of the aggregate of the surface layer, the middle and lower surface layer, and the base layer of the newly built highway, as shown in Tables 1 and 2.

[0041] Table 1 Requirements of coarse aggregate for asphalt mixture on acicular and flaky particle content

[0042]

[0043] Table 2 Requirements of coarse aggregate for asphalt mixture on broken surface

[0044]

[0045] According to the current situation and specification of highway asphalt pavement construction, the proportion of particles with acicular, flaky, no or one required broken surface is low, and the proportion of particles with two or more than two required broken surfaces is large. Therefore, the present application uses a sorting device to first put the aggregate particles with acicular, flaky, no or one required broken surface into different storage boxes, and uses a conveying belt to transport the particles with two or more than two required broken surfaces to the storage box e, thereby improving the efficiency and accuracy of classifying and conveying the aggregate particles.

[0046] The technical solutions of the present application or the technical solutions designed by the person skilled in the art under the inspiration of the technical solutions of the present application, which achieve the above technical effects, all fall within the protection scope of the present application.

Claims

1. A modular equipment for identifying and screening different shape characteristic aggregate particles, comprising a feeding system, a screening system, a conveying system, a 3D laser scanning system, an image acquisition and processing system, an aggregate screening system, the feeding system comprising an aggregate bin and a conveyor belt a, the screening system comprising a sleeve screen, a vibrating table and a feeding bin, the conveying system comprising sensors and a conveyor belt, the 3D laser scanning system comprising a 3D laser scanner, a laser receiving target, a support frame a, a conveyor belt b, the image acquisition and processing system comprising an image acquisition device, a support frame b, a conveyor belt c, the aggregate screening system comprising a sorter and a storage bin; the aggregate bin of the feeding system is connected with the sleeve screen of the screening system through the conveyor belt a, the vibrating table is located below the sleeve screen, the sleeve screen is fixedly connected with the feeding bin on the side close to the conveying system, the conveyor belt is located below the discharge side of the feeding bin, a plurality of sensors are arranged below different regions of the conveyor belt, the 3D laser scanning system and the image acquisition and processing system are arranged above the conveyor belt through the support frame a and the support frame b respectively, the sorter of the aggregate screening system is distributed on both sides of the conveyor belt, the storage bin is respectively located below the conveyor belt and at the end of the conveyor belt, two sets of modules arranged in the order of 3D laser scanner, image acquisition and processing system, aggregate screening system from left to right are arranged in the length range of the conveyor belt.

2. The modular apparatus for identifying and sorting differently morphologically characterized aggregate particles according to claim 1, wherein, The sleeve screen is provided with an aggregate valve, and a ball joint movable discharger is arranged in the sleeve screen, the vibrating table vibrates the sleeve screen to screen the aggregate particles, the aggregate particles of different particle sizes are discharged into different size screens, then the discharger discharges the aggregate particles of a certain particle size into the feeding bin through the aggregate valve, and the aggregate particles of the same particle size are batch fed, picked and classified according to different shapes.

3. The modular apparatus for identifying and sorting differently morphologically characterized aggregate particles of claim 1, wherein, The 3D laser scanner is located on the support frame a, and is moved, rotated and adjusted in position through the support frame a and the conveyor belt b, a three-dimensional model of the aggregate particles is constructed in batches, the needle and flake coefficients of different aggregate particles are calculated, and the aggregate particles with a needle and flake coefficient greater than or equal to 3 are picked in batches by the sorter.

4. The modular apparatus for identifying and sorting differently morphologically characterized aggregate particles of claim 1, wherein, The image acquisition device is located on the support frame b, and is moved, rotated and adjusted in position through the support frame b and the conveyor belt c, a three-dimensional model of the aggregate particles is constructed in batches by using image processing technology, the number of required fracture surfaces contained in the aggregate particles is accurately calculated, and the aggregate particles with different numbers of required fracture surfaces are picked and classified in batches by the sorter.

5. The modular apparatus for identifying and sorting differently morphologically characterized aggregate particles of claim 1, wherein, The storage bin comprises three sets of storage systems, two sets of storage systems located in the length range of the conveyor belt each comprise four storage boxes, and two sets of modules arranged in the order of 3D laser scanner, image acquisition and processing system, aggregate screening system from left to right screen different shape aggregate particles twice, needle-shaped particles, flake-shaped particles, aggregate particles without required fracture surfaces and aggregate particles with one required fracture surface are respectively put into four different storage boxes, the storage boxes are provided with a discharger and a discharge port, and aggregate particles with two or more required fracture surfaces are conveyed to the third set of storage systems at the end of the conveyor belt by the conveyor belt.

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