Automatic repair method for PDC drill bit defects

Abstract

The present invention discloses an automatic repair method for PDC drill bit defects, which belongs to the technical field of laser equipment modification. The technical problem to be solved by the present invention is how to realize the automatic detection and automatic repair of wear such as broken teeth and bonding layer shedding of PDC drill bits. The technical solution adopted is as follows: the method uses a manipulator equipped with a three-dimensional scanner to perform rapid three-dimensional scanning and measurement of the worn parts of the PDC drill bit, compares and calculates the scanning results with the standard digital model of the PDC drill bit through data processing, obtains the position and three-dimensional model shape of the area to be repaired of the PDC drill bit, and automatically plans the cladding path. At the same time, the manipulator is controlled to guide the laser cladding equipment to complete the repair of the damaged body on the PDC drill bit, thereby forming repair paths for different damage degrees, thereby completing the automatic repair of the damaged body of the PDC drill bit.

Description

Technical Field

[0001] The invention relates to the technical field of laser equipment repair, in particular to an automatic repair method for a PDC drill bit defect. Background Art

[0002] Steel-body PDC drill bits have good effects when used in special formations. However, the compressive strength of some formations is relatively high, which causes great abrasion to the steel-body PDC drill bits during the drilling process, resulting in great wear of the drill bit body and cutting teeth. The cost of steel-body PDC drill bits is relatively high. Therefore, repairing worn steel-body PDC drill bits can bring great economic value.

[0003] The main method of repairing drill bits is to place selected coating materials on the surface of the coated PDC drill bit in the form of different fillers. After laser processing, it is melted simultaneously with a thin layer on the surface of the substrate, and then quickly solidified to form a surface coating with extremely low dilution and metallurgical bonding with the substrate material, thereby significantly improving the wear resistance, corrosion resistance, heat resistance, oxidation resistance and electrical properties of the substrate surface.

[0004] Currently, the laser repair robots and 3D scanners on the market are independent systems that cannot achieve automated detection and automatic repair.

[0005] Therefore, how to realize the automatic detection and automatic repair of PDC drill bit wear such as broken teeth and bonding layer shedding is a technical problem that needs to be solved urgently. Summary of the Invention

[0006] The technical task of the present invention is to provide an automatic repair method for PDC drill bit defects to solve the problem of how to realize automatic detection and automatic repair of wear such as broken teeth and bonding layer shedding of PDC drill bits.

[0007] The technical task of the present invention is achieved in the following manner: an automatic repair method for a PDC drill bit defect, which uses a manipulator equipped with a 3D scanner to perform rapid 3D scanning and measurement of the worn part of the PDC drill bit. The scanning results are compared and calculated with the standard digital model of the PDC drill bit through data processing to obtain the position and 3D model shape of the area to be repaired of the PDC drill bit, and the cladding path is automatically planned. At the same time, the manipulator is controlled to guide the laser cladding equipment to complete the repair of the damaged part on the PDC drill bit, forming repair paths for different damage degrees, thereby completing the automatic repair of the damaged part of the PDC drill bit; the details are as follows:

[0008] S1. Acquire 3D data of a standard PDC drill bit and a worn PDC drill bit;

[0009] S2. performing Boolean operations on the three-dimensional data of the standard PDC drill bit and the worn PDC drill bit to obtain the damaged part of the worn PDC drill bit;

[0010] S3, extracting the defective surface of the worn PDC drill bit;

[0011] S4. Processing the defective surface of the worn PDC drill bit to obtain point cloud data;

[0012] S5. Slice the point cloud according to the point cloud data;

[0013] S6. Obtain the normal vector of the processing point according to the point cloud slicing result;

[0014] S7, planning the cladding path according to the normal vector of the processing point;

[0015] S8. Complete the cladding repair according to the cladding path.

[0016] Preferably, a three-dimensional scanning sensor is installed on the cladding head of the laser cladding equipment to automatically obtain a three-dimensional model of the PDC drill bit. By comparing the scanned three-dimensional model data of the PDC drill bit with the solid model data of the PDC drill bit, the defective body data with insufficient volume and thickness is removed, and the three-dimensional data of the defective area of ​​the PDC drill bit is obtained, and then the three-dimensional solid model of the damaged body of the PDC drill bit is obtained.

[0017] More preferably, according to the geometric characteristics of the PDC drill bit, automatic recognition technology is used and the corresponding measurement method is selected to obtain the surface point cloud data of the PDC drill bit, and the surface point cloud data of the PDC drill bit obtained by the three-dimensional scanner is preprocessed; at the same time, for the point cloud data extraction of the defective area of ​​the broken PDC drill bit, Boolean operations are applied to extract the data of the defective area of ​​the broken drill bit.

[0018] More preferably, when the 3D scanner is scanning a fixed-wear PDC drill bit, marking points are attached to the PDC drill bit to facilitate data position registration and alignment, and to complete the scanning and adjustment of different angles of the robotic arm at the same time; after the data of the defective PDC drill bit are collected, the standard PDC drill bit is fixed again and scanned by the 3D scanner to collect the 3D scanning data of the standard PDC drill bit; the obtained 3D scanning data of the standard PDC drill bit is automatically compared with the CAD model of the standard PDC drill bit by executing the macro command of the point cloud data processing software, and then Boolean operations are performed and wear data (entities with insufficient volume or thickness) are removed.

[0019] More preferably, a range clipping algorithm based on Boolean operations selects the pattern fill set AA that intersects with the clipping range, traverses each pattern fill B1 in the intersection set AA1, extracts the pattern fill boundary C1, converts it into a face domain D1, performs a Boolean operation with the face domain E1 converted from the clipping range, takes the intersection, obtains the face domain D1, extracts the boundary G1 of the intersecting face F1, and obtains the new pattern after clipping for filling;

[0020] Convert the pattern fill and the cutting range line into a domain, and obtain the cutting result by taking the intersection. For the pattern fill H1, extract its boundary C1, and complete the cutting with the help of Boolean operation. Perform Boolean operation on the domain D1 obtained by pattern fill conversion and the domain E1 obtained by cutting range line conversion to obtain domain F1 = D1 ∩ E1. Domain F1 is the result after cutting. After obtaining the cut domain F1, convert domain F1 into pattern fill. According to the characteristics of pattern fill, directly specify the boundary of the original pattern fill B1 as domain H1 to obtain the cut pattern fill H1.

[0021] More preferably, the adjacent points on both sides of the defective data slice of the worn PDC drill bit are matched, and the adjacent points on both sides are intersected with the slice to obtain the intersection point on the slice, and then the point cloud data after the point cloud is sliced ​​is obtained.

[0022] More preferably, point cloud slicing is a given point cloud data model. By using parallel and equally spaced planes to intercept the point cloud data model and extracting sampling points on the cross-sectional contour line of the intercepted point cloud model as the cladding path, the point cloud slicing is described, the cutting plane is set, and the cross-sectional contour line is obtained by intersecting the point cloud data cutting planes to obtain the data points obtained by cutting.

[0023] More preferably, during the processing, the normal vector of each processing point is calculated to determine the posture of the laser gun head at the processing point; after retrieving and slicing, the data of the processing point concentration is obtained, and a number of neighboring points are found in the point cloud before slicing. By setting an appropriate neighbor radius, the neighboring points are grouped into a set; then, according to the covariance matrix, the vector corresponding to the minimum eigenvalue in the data set is calculated to obtain the normal vector of this area, which is used as the posture direction of the cladding head to perform surface cladding repair operations on the damaged drill bit.

[0024] The automatic repair method for PDC drill bit defects of the present invention has the following advantages:

[0025] (1) The present invention uses automatic recognition technology to perform data processing and three-dimensional reconstruction. Based on the measurement data, a three-dimensional geometric modeling method is used to reconstruct the physical model of the PDC drill bit, realize path planning for curved surface parts, simulate the planning of the robot arm processing path, and perform numerical simulation of the robot arm during the cladding repair process to achieve optimal control of its processing process, thereby achieving the purpose of improving its processing quality;

[0026] (2) The present invention can control the scanner to perform scanning measurement, obtain drill bit defect data, compare the defect data with the original drill bit data model, obtain the defect model, and then receive the path file data sent by the system and continuously send it to the robot, so that the robot executes the repair process; that is, before repairing the PDC drill bit, the PDC drill bit must first be automatically inspected, and after the inspection is completed, the cladding head performs cladding repair according to the inspection structure, thereby realizing automated inspection and automated repair of the PDC drill bit;

[0027] (3) The present invention fixes the PDC drill bit that needs to be repaired, and the scanning program of the three-dimensional scanning system completes the three-dimensional scanning data collection of the drill bit to be repaired; the obtained scanning data is automatically compared with the ideal CAD model (intact PDC drill bit model data) by executing the point cloud data processing software command program, and then Boolean operations are performed to remove wear data (entities with insufficient volume or thickness), and finally the entity data of the damaged drill bit is obtained. Obtaining intact point cloud data is a prerequisite for path planning of curved parts, which improves the efficiency of automated detection.

[0028] (4) The present invention aligns the scan data of the damaged PDC drill bit to the coordinate system of the complete PDC drill bit digital model (under the working coordinate system) of the drill bit, realizes the comparison result of the scan data of the damaged PDC drill bit and the original complete drill bit 3D CAD digital model, runs and outputs the Boolean operation result after the scan data of the damaged PDC drill bit and the 3D CAD digital model of the drill bit are aligned (damage of insufficient volume and insufficient thickness is normal wear and does not meet the standard for repair), and finally extracts the model map of the damaged part to provide a reference model for realizing the automated repair of the PDC drill bit, thereby improving the accuracy and efficiency of the automated repair;

[0029] (V) In order to reduce operation time and improve processing efficiency, the present invention needs to pre-process the target pattern fill according to the relative relationship between the target pattern fill and the cutting range line, and screen out the pattern fill that intersects with the cutting range line. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below with reference to the accompanying drawings.

[0031] Attachment Figure 1 A flowchart of an automatic repair method for a PDC drill bit defect;

[0032] Attachment Figure 2 The flowchart of the range cutting algorithm based on Boolean operation is shown in FIG. DETAILED DESCRIPTION

[0033] The following is a detailed description of an automatic repair method for a PDC drill bit defect according to the present invention with reference to the accompanying drawings and specific embodiments.

[0034] Example 1:

[0035] As attached Figure 1 As shown, this embodiment provides an automatic repair method for PDC drill bit defects. The method uses a manipulator equipped with a 3D scanner to perform rapid 3D scanning and measurement of the worn parts of the PDC drill bit. The scanning results are compared and calculated with the standard digital model of the PDC drill bit through data processing to obtain the position and 3D model shape of the area to be repaired of the PDC drill bit, and the cladding path is automatically planned. At the same time, the manipulator is controlled to guide the laser cladding equipment to complete the repair of the damaged part on the PDC drill bit, forming repair paths for different damage degrees, thereby completing the automatic repair of the damaged part of the PDC drill bit. The details are as follows:

[0036] S1. Acquire 3D data of a standard PDC drill bit and a worn PDC drill bit;

[0037] S2. performing Boolean operations on the three-dimensional data of the standard PDC drill bit and the worn PDC drill bit to obtain the damaged part of the worn PDC drill bit;

[0038] S3, extracting the defective surface of the worn PDC drill bit;

[0039] S4. Processing the defective surface of the worn PDC drill bit to obtain point cloud data;

[0040] S5. Slice the point cloud according to the point cloud data;

[0041] S6. Obtain the normal vector of the processing point according to the point cloud slicing result;

[0042] S7, planning the cladding path according to the normal vector of the processing point;

[0043] S8. Complete the cladding repair according to the cladding path.

[0044] In this embodiment, a three-dimensional scanning sensor is installed on the cladding head of the laser cladding equipment to automatically obtain a three-dimensional model of the PDC drill bit. By comparing the scanned three-dimensional model data of the PDC drill bit with the solid model data of the PDC drill bit, the defective body data with insufficient volume and thickness is removed, and the three-dimensional data of the defective area of ​​the PDC drill bit is obtained, and then the three-dimensional solid model of the damaged body of the PDC drill bit is obtained.

[0045] In this embodiment, based on the geometric characteristics of the PDC drill bit, automatic recognition technology is used and the corresponding measurement method is selected to obtain the surface point cloud data of the PDC drill bit, and the surface point cloud data of the PDC drill bit obtained by the three-dimensional scanner is preprocessed; at the same time, the point cloud data of the defective area of ​​the damaged PDC drill bit is extracted, and Boolean operations are applied to extract the data of the defective area of ​​the damaged drill bit.

[0046] In this embodiment, when the 3D scanner is scanning the fixed wear PDC drill bit, marking points are attached to the PDC drill bit to facilitate data position registration and alignment, and to complete the scanning and adjustment of different angles of the robotic arm at the same time; after the data of the defective PDC drill bit is collected, the standard PDC drill bit is fixed again and scanned by the 3D scanner to collect the 3D scanning data of the standard PDC drill bit; the obtained 3D scanning data of the standard PDC drill bit is automatically compared with the CAD model of the standard PDC drill bit by executing the macro command of the point cloud data processing software, and then Boolean operations are performed and wear data (entities with insufficient volume or thickness) are removed.

[0047] As attached Figure 2 As shown, in this embodiment, the range clipping algorithm based on Boolean operations filters out the pattern fill set AA that intersects with the clipping range, traverses each pattern fill B1 in the intersection set AA1, extracts the boundary C1 of the pattern fill, converts it into a surface area D1, performs a Boolean operation with the surface area E1 converted from the clipping range, takes the intersection, obtains the surface area D1, extracts the boundary G1 of the intersecting surface F1, and obtains the new pattern after clipping for filling;

[0048] Convert the pattern fill and the cutting range line into a domain, and obtain the cutting result by taking the intersection. For the pattern fill H1, extract its boundary C1, and complete the cutting with the help of Boolean operation. Perform Boolean operation on the domain D1 obtained by pattern fill conversion and the domain E1 obtained by cutting range line conversion to obtain domain F1 = D1 ∩ E1. Domain F1 is the result after cutting. After obtaining the cut domain F1, convert domain F1 into pattern fill. According to the characteristics of pattern fill, directly specify the boundary of the original pattern fill B1 as domain H1 to obtain the cut pattern fill H1.

[0049] In this embodiment, adjacent points on both sides of the defective data slice of the worn PDC drill bit are matched, and the adjacent points on both sides are intersected with the slice to obtain the intersection point on the slice, and then the point cloud data after the point cloud is sliced ​​is obtained.

[0050] In this embodiment, point cloud slicing is performed on a given point cloud data model. The point cloud data model is intercepted by using planes that are parallel to each other and equidistant from each other, and the sampling points on the cross-sectional contour line of the intercepted point cloud model are extracted as the cladding path. By describing the point cloud slicing, setting the cutting plane, and obtaining the cross-sectional contour line by intersecting the point cloud data cutting plane, the data points obtained by cutting can be obtained.

[0051] In this embodiment, during the processing, the normal vector of each processing point is calculated to determine the posture of the laser gun head at the processing point; after retrieving and slicing, the data of the processing point concentration is obtained, and a number of neighboring points are found in the point cloud before slicing. By setting an appropriate neighbor radius, the neighboring points are grouped into a set; then, according to the covariance matrix, the vector corresponding to the minimum eigenvalue in the data set is calculated to obtain the normal vector of this area, which is used as the posture direction of the cladding head to perform surface cladding repair operations on the damaged drill bit.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for automatically repairing a PDC drill bit defect, characterized in that: The method uses a manipulator equipped with a 3D scanner to quickly perform 3D scanning and measurement of the worn parts of the PDC drill bit. The scanning results are compared and calculated with the standard digital model of the PDC drill bit through data processing to obtain the position of the area to be repaired and the 3D model shape of the PDC drill bit. The cladding path is automatically planned, and the manipulator is controlled to guide the laser cladding equipment to complete the repair of the damaged part on the PDC drill bit, forming repair paths for different damage degrees, thereby completing the automatic repair of the damaged part of the PDC drill bit. The details are as follows: S1. Acquire 3D data of a standard PDC drill bit and a worn PDC drill bit; S2. performing Boolean operations on the three-dimensional data of the standard PDC drill bit and the worn PDC drill bit to obtain the damaged part of the worn PDC drill bit; S3, extracting the defective surface of the worn PDC drill bit; S4. Processing the defective surface of the worn PDC drill bit to obtain point cloud data; S5. Slice the point cloud according to the point cloud data; S6. Obtain the normal vector of the processing point according to the point cloud slicing result; S7, planning the cladding path according to the normal vector of the processing point; S8, completing the cladding repair according to the cladding path; The range clipping algorithm based on Boolean operations selects the pattern fill set AA that intersects with the clipping range, traverses each pattern fill B1 in the intersecting set AA1, extracts the pattern fill boundary C1, converts it into a surface area D1, performs a Boolean operation with the surface area E1 converted from the clipping range, takes the intersection, obtains the surface area D1, extracts the boundary G1 of the intersecting surface F1, and obtains the new pattern after clipping for filling. Convert the pattern fill and the cutting range line into a region, and obtain the cutting result by taking the intersection. For the pattern fill H1, extract its boundary C1, and complete the cutting with the help of Boolean operation. Perform Boolean operation on the region D1 obtained by pattern fill conversion and the region E1 obtained by cutting range line conversion to obtain the region F1=D1∩E1. The region F1 is the result after cutting. After obtaining the cut region F1, convert the region F1 into a pattern fill. According to the characteristics of the pattern fill, directly specify the boundary of the original pattern fill B1 as the region H1 to obtain the cut pattern fill H1. Match the adjacent points on both sides of the defective data slice of the worn PDC drill bit, intersect the adjacent points on both sides with the slice, obtain the intersection point on the slice, and then obtain the point cloud data after the point cloud is sliced; Point cloud slicing is a process of giving a point cloud data model. By using parallel and equally spaced planes to intercept the point cloud data model and extracting sampling points on the cross-sectional contour line of the intercepted point cloud model as the cladding path, the point cloud slicing is described, the cutting plane is set, and the cross-sectional contour line is obtained by intersecting the point cloud data cutting planes to obtain the data points obtained by cutting.

2. The automatic repair method for PDC drill bit defects according to claim 1, characterized in that: A 3D scanning sensor is installed on the cladding head of the laser cladding equipment to automatically obtain a 3D model of the PDC drill bit. By comparing the scanned 3D model data of the PDC drill bit with the solid model data of the PDC drill bit, the defective body data with insufficient volume and thickness is removed, and the 3D data of the defective area of ​​the PDC drill bit is obtained, and then the 3D solid model of the damaged body of the PDC drill bit is obtained.

3. The automatic repair method for PDC drill bit defects according to claim 1 or 2, characterized in that: According to the geometric characteristics of the PDC drill bit, automatic recognition technology is used and the corresponding measurement method is selected to obtain the surface point cloud data of the PDC drill bit. The surface point cloud data of the PDC drill bit obtained by the 3D scanner is preprocessed. At the same time, Boolean operations are applied to extract the point cloud data of the defective area of ​​the damaged PDC drill bit.

4. The automatic repair method for PDC drill bit defects according to claim 3, characterized in that: When the 3D scanner is scanning a fixed-wear PDC drill bit, marking points are attached to the PDC drill bit to facilitate data position registration and alignment, and to complete the scanning and adjustment of different angles of the robotic arm at the same time; after the data of the defective PDC drill bit is collected, the standard PDC drill bit is fixed again and scanned by the 3D scanner to collect the 3D scanning data of the standard PDC drill bit; the obtained 3D scanning data of the standard PDC drill bit is automatically compared with the CAD model of the standard PDC drill bit by executing the macro command of the point cloud data processing software, and then Boolean operations are performed and the wear data is removed.

5. The automatic repair method for PDC drill bit defects according to claim 1, characterized in that: During the machining process, the normal vector of each machining point is calculated to determine the posture of the laser gun head at the machining point. After slicing, the data in the machining point concentration is retrieved, and several neighboring points are found in the point cloud before slicing. By setting an appropriate neighbor radius, the neighboring points are formed into a set. Then, based on the covariance matrix, the vector corresponding to the minimum eigenvalue in the data set is calculated to obtain the normal vector of this area, which is used as the posture direction of the cladding head to perform surface cladding repair operations on the damaged drill bit.

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