Method for calculating volume abrasion loss of TBM (Tunnel Boring Machine) hob

Abstract

The invention discloses a TBM hob volume abrasion loss calculation method. The method comprises the steps that firstly, three-dimensional scanning parameters of a hob ring are determined through calibration; performing three-dimensional scanning on the new cutter ring to obtain point cloud data of the new cutter ring; and by preprocessing the point cloud data, a closed triangular mesh model of the new cutter ring is constructed, so that the volume of the new cutter ring is calculated. After the cutter ring is abraded and detached, three-dimensional scanning is conducted on the cutter ring, point cloud data of the abraded cutter ring are obtained, the point cloud data are preprocessed, a closed triangular mesh model of the abraded cutter ring is constructed, and then the size of the abraded cutter ring is calculated. And subtracting the volume of the abraded cutter ring from the volume of the new cutter ring to obtain the volume abrasion loss of the hob. The method not only can accurately calculate the volume abrasion loss of the normally abraded hob, but also can calculate the abrasion loss of the fractured and eccentric abraded hob, and can comprehensively reflect the overall abrasion of the hob.

Description

Technical Field

[0001] The invention relates to the technical field of roller cutter measurement, and in particular to a method for calculating the volume wear of a TBM roller cutter. Background Art

[0002] At present, TBM (hard rock tunnel boring machine) is widely used in hard rock tunnel construction. The prediction of cutter wear has always been an important direction of TBM excavation technology research. Cutting rock mass causes wear. Under specific geological conditions, the wear speed, wear and damage form of cutters of different materials and cutter types can reflect the performance of the cutter. Therefore, a comprehensive and reasonable evaluation of the wear speed of the cutter is of great reference significance for the material and selection of cutters under specific geological conditions.

[0003] At present, manual measurement or intelligent monitoring systems are mostly used to obtain the linear wear of the hob, but most of these methods only characterize the wear of the tool by measuring the average radial wear of a few points on the cutter ring, and cannot obtain the volume wear of the hob. Hob wear is mostly uneven wear, so these methods are difficult to fully reflect the wear of the hob. In addition, these methods are difficult to quantify and evaluate abnormal hob wear such as fracture and eccentric wear. Therefore, the current methods are difficult to achieve accurate evaluation of the adaptability of hobs of different materials and cutter types to specific geological conditions. Summary of the invention

[0004] In order to overcome the limitations of current tool wear measurement methods, the main purpose of the present invention is to provide a method for calculating the volume wear of TBM cutters. The method can calculate the volume wear of the cutter, comprehensively evaluate the wear of the cutter, and quantify the wear of the broken and eccentrically worn cutters.

[0005] The present invention adopts the following technical solution:

[0006] A method for calculating the volume wear of a TBM cutter comprises the following steps:

[0007] Step 1: Calibration, determine the hob cutter ring 3D scanning measurement parameters;

[0008] Step 2: Scan the new hob cutter ring to obtain the 3D point cloud data of the new cutter ring;

[0009] Step 3: Process the 3D point cloud data of the new cutter ring, construct a closed triangular mesh model of the new cutter ring, and calculate the volume of the new cutter ring;

[0010] Step 4: Scan the worn hob cutter ring to obtain the 3D point cloud data of the worn cutter ring;

[0011] Step 5: Process the 3D point cloud data of the worn cutter ring, construct a closed triangular mesh model of the worn cutter ring, and calculate the volume of the worn cutter ring;

[0012] Step 6: Subtract the volume of the worn cutter ring from the volume of the new cutter ring to obtain the volume wear of the hob.

[0013] Specifically, in step 1, the three-dimensional scanning parameters of the hob cutter ring include a scanning distance and a scale.

[0014] Specifically, in step 2 and step 4, a dynamic scanning method is used to scan the complete profile of the hob cutter ring.

[0015] Specifically, in step 3 and step 5, the processing of the three-dimensional point cloud data includes point cloud denoising and resampling.

[0016] Specifically, in step 3 and step 5, CloudCompare software is used to generate a circle with the same size as the inner diameter of the cutter ring to fill the vacant surface of the cutter ring.

[0017] Specifically, in step 3 and step 5, after the missing surfaces of the cutter ring are filled, the Alpha Shape algorithm is used to construct a closed triangular mesh model of the cutter ring.

[0018] Specifically, in step 3 and step 5, the volume of the cutter ring is calculated using a triangular mesh algorithm and the scale.

[0019] The beneficial effects of the present invention are:

[0020] The proposed method can accurately calculate the volume wear of the hob, realize a comprehensive and reasonable evaluation of the hob wear, and quantify the wear of the fractured and eccentrically worn hobs. It can also evaluate the adaptability of different types of hobs to specific geological conditions and provide a reliable reference for tool selection under specific geological conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is a flow chart of the method for calculating the volume wear of the TBM cutter of the present invention.

[0023] Figure 2 Schematic diagram of the original three-dimensional model of the new cutter ring involved in the embodiment of the present invention.

[0024] Figure 3 It is a schematic diagram of a three-dimensional model of a new cutter ring after preprocessing according to an embodiment of the present invention.

[0025] Figure 4It is a schematic diagram of a closed triangular mesh model of a new cutter ring involved in an embodiment of the present invention.

[0026] Figure 5 It is a schematic diagram of the original three-dimensional model of the worn cutter ring involved in the embodiment of the present invention.

[0027] Figure 6 It is a schematic diagram of a three-dimensional model of a worn cutter ring after pretreatment according to an embodiment of the present invention.

[0028] Figure 7 It is a schematic diagram of a closed triangular mesh model of a wear cutter ring involved in an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to make those of ordinary skill in the art better understand the technical solutions of the present application, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention.

[0030] like Figure 1 As shown in FIG. 1 , a method for calculating the volume wear of a TBM cutter is shown in FIG. 1 . The steps are as follows:

[0031] Step 1: Determine two scanning parameters, scanning distance and scale, through manual scanning calibration. The scanning distance is used to control the effective range and resolution of the scan. The scale is the ratio of the scan size to the actual size, which is used for subsequent volume calculation. In this embodiment, the scale is 1:1000.

[0032] Step 2: Use a 3D scanning device to scan the new hob cutter ring to obtain the original 3D point cloud data of the new cutter ring. The 3D scanning device can use a laser scanner, such as FARO and Leica, or an optical scanner, such as Artec and Creaform. In this embodiment, a FARO laser scanner is used. The scanning method is manual dynamic scanning, and the contour of the new hob cutter ring needs to be scanned. After the scanning is completed, the original 3D model of the cutter ring is constructed based on the original 3D point cloud data of the new cutter ring, such as Figure 2 shown.

[0033] Step 3: Preprocess the 3D point cloud data of the new knife ring, build a closed triangular mesh model of the knife ring, and calculate the volume of the new knife ring. The preprocessing includes two steps: denoising and resampling. Affected by environmental factors, the collected original 3D point cloud data of the knife ring has obvious noise points. In order to prevent these noise points from affecting the construction of the subsequent 3D model, these noise points are manually deleted. At the same time, the amount of point cloud data is relatively large. In order to improve the efficiency of subsequent calculations, the point cloud data is resampled through homogenization and point cloud downsampling, and the contour points of the knife ring are retained, thereby greatly improving the efficiency of subsequent calculations. The 3D model of the knife ring after preprocessing is as follows. Figure 3 As shown in the figure, since the knife ring is a non-closed object, the algorithm cannot calculate the volume. Therefore, after preprocessing, CloudCompare software is used to generate a circle of the same size as the inner diameter of the knife ring to fill the gap. In this embodiment, the inner diameter of the knife ring is 354 mm. After the gap is filled, the Alpha Shape algorithm is used to construct a complete triangle mesh model of the knife ring. The closed triangle mesh model of the knife ring is as shown in the figure. Figure 4 Finally, the volume of the knife circle is calculated by triangular mesh algorithm and scale.

[0034] In the Alpha Shape algorithm, different Alpha values ​​generate different knife ring triangle mesh models, which affects the calculation results of the knife ring volume. Therefore, the best Alpha value is selected by the following method:

[0035] Step a: Set the Alpha value range to 0 to 1, start from 0, traverse this range, increase by 0.01 each time, and build a triangular mesh model of the knife circle corresponding to each Alpha value;

[0036] Step b: Calculate the volume of the triangular mesh model of the cutter ring corresponding to each Alpha value and compare it with the actual volume of the cutter ring. When the volume error is the smallest, the corresponding Alpha value is the optimal Alpha value. At the same time, this value is also used to construct the triangular mesh model of the worn hob cutter ring.

[0037] In this embodiment, the optimal Alpha value obtained by the above method is 0.05, and the calculated volume of the triangular mesh model of the new knife ring is 13974.34cm 3 , the actual volume of the new knife ring is 14007.81cm 3 , the error is 0.2%, so the volume calculated by this method is basically consistent with the actual volume.

[0038] Step 4: Scan the worn hob cutter ring to obtain the 3D point cloud data of the worn hob cutter ring. The scanning parameters, scanning equipment, and scanning method should be the same as those in step 2. After the scan is completed, the original 3D model of the worn hob cutter ring is constructed based on the original 3D point cloud data of the worn hob cutter ring, such as Figure 5 shown.

[0039] Step 5: Use the same denoising and resampling method as step 3 to preprocess the 3D point cloud data of the worn cutter ring to obtain the preprocessed 3D model of the worn cutter ring, such as Figure 6 Then use CloudCompare software to generate a circle with a diameter of 354 mm to fill the gaps in the worn cutter ring. After the gaps are filled, the Alpha Shape algorithm is used to construct a triangular mesh model of the worn cutter ring with an Alpha value of 0.05. The constructed closed triangular mesh model of the worn cutter ring is shown in Figure 7 Finally, the volume of the worn cutter ring is calculated using a triangular mesh algorithm and a scale. In this embodiment, the calculated volume of the worn cutter ring is 13105.71 cm 3 .

[0040] Step 6: Subtract the calculated volume of the worn cutter ring from the calculated volume of the new cutter ring to obtain the volume wear of the cutter. In this embodiment, the calculated volume wear of the cutter is 868.63 cm 3 .

[0041] Unless otherwise stated, any technical solution disclosed in the present invention disclosed above, if it discloses a numerical range, then the disclosed numerical range is a preferred numerical range, and any technician in the field should understand that the preferred numerical range is only a numerical value with a more obvious technical effect or representative value among many implementable numerical values. Since there are too many numerical values ​​to be exhaustive, the present invention discloses some numerical values ​​to illustrate the technical solution of the present invention, and the numerical values ​​listed above should not constitute a limitation on the scope of protection of the present invention.

[0042] The above embodiments are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications may be made based on the above description. It is not necessary and impossible to list all the embodiments here. However, the obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A method for calculating the volume wear of a TBM cutter, characterized in that: The method first determines the three-dimensional scanning parameters of the TBM hob cutter ring through calibration; then performs three-dimensional scanning on the new cutter ring to obtain its point cloud data; by preprocessing the point cloud data, a closed triangular mesh model of the new cutter ring is constructed, thereby calculating the volume of the new cutter ring; after the cutter ring is worn and disassembled, a three-dimensional scanning is performed on it to obtain the point cloud data of the cutter ring after wear, and the point cloud data is preprocessed to construct a closed triangular mesh model of the worn cutter ring, and then the volume of the worn cutter ring is calculated; the volume of the worn cutter ring is subtracted from the volume of the new cutter ring to obtain the volume wear amount of the hob; specifically, the following steps are included: Step 1: Calibration, determine the 3D scanning measurement parameters of the TBM cutter ring; Step 2: Scan the new TBM cutter ring to obtain the 3D point cloud data of the new cutter ring; Step 3: Process the 3D point cloud data of the new cutter ring, construct a closed triangular mesh model of the new cutter ring, and calculate the volume of the new cutter ring; Step 4: Scan the worn TBM cutter ring to obtain the 3D point cloud data of the worn cutter ring; Step 5: Process the 3D point cloud data of the worn cutter ring, construct a closed triangular mesh model of the worn cutter ring, and calculate the volume of the worn cutter ring; Step 6: Subtract the volume of the worn cutter ring from the volume of the new cutter ring to obtain the volume wear of the hob.

2. A method for calculating volume wear of a TBM cutter according to claim 1, characterized in that: In step 1, the three-dimensional scanning measurement parameters of the TBM cutter ring include scanning distance and scale.

3. The method for calculating the volume wear of a TBM cutter according to claim 1, characterized in that: In step 2 and step 4, a dynamic scanning method is used to scan the complete profile of the TBM hob cutter ring.

4. The method for calculating the volume wear of a TBM cutter according to claim 1, characterized in that: In step 3 and step 5, the processing of the three-dimensional point cloud data includes point cloud denoising and resampling.

5. The method for calculating the volume wear of a TBM cutter according to claim 1, characterized in that: In step 3 and step 5, CloudCompare software is used to generate a circle with the same size as the inner diameter of the cutter ring to fill the vacant surface of the cutter ring.

6. A method for calculating the volume wear of a TBM cutter according to claim 1, characterized in that: In step 3 and step 5, after the missing surfaces of the cutter ring are filled, the Alpha Shape algorithm is used to construct a closed triangular mesh model of the cutter ring.

7. The method for calculating the volume wear of a TBM cutter according to claim 1, characterized in that: In step 3 and step 5, the volume of the cutter ring is calculated using a triangular mesh algorithm and the scale.

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