Method for position guidance of flexible contour grinding of cylindrical shell weld seams

Abstract

The application discloses a kind of flexible conformal grinding position guiding methods of cylindrical shell weld, comprising: based on weld three-dimensional point set fitting generation weld three-dimensional surface model, realize weld local geometric parameter quantization and image anomaly fusion, form the defect section list containing defect position, type and severity, improve defect detection comprehensiveness and positioning accuracy.Define weld direction and grinding reference according to weld center line and weld three-dimensional surface model, build weld local coordinate system, provide stable, conformal surface direction reference for subsequent trajectory and attitude control.Introduce normal compensation on the basis of weld center line spline fitting, form actual grinding trajectory that conforms to the curvature change of cylindrical shell weld, ensure that grinding head is continuously conformed.According to the comprehensive abnormal degree calculated from weld local geometric parameter and defect section list, the weld area is divided, realize the concentrated processing of abnormal section and the automatic skipping of qualified section, improve processing pertinence.

Description

Technical Field

[0001] This invention relates to the field of intelligent weld processing technology, and in particular to a method for guiding the position of flexible conformal grinding of weld seams in cylindrical shells. Background Technology

[0002] Currently, the grinding of weld seams in cylindrical shells mainly employs manual grinding, teach-in robot grinding, and automated grinding based on fixed trajectories. Manual grinding is highly dependent on the operator's experience, resulting in low processing efficiency and poor surface consistency. Teach-in robot grinding requires manual instruction to generate motion trajectories and is only suitable for standard workpieces with regular shapes and small processing deviations. Automated grinding based on fixed trajectories mostly follows preset paths or simplified geometric models, which improves the level of automation to some extent, but it is difficult to adapt to the spatial orientation, dimensional deviations, and morphological changes of actual weld seams.

[0003] The aforementioned existing technologies generally suffer from the following technical problems when guiding the grinding position of weld seams on curved surfaces of cylindrical shells: (1) The grinding trajectory and the posture of the grinding head cannot be adjusted in real time according to the changes in the spatial curvature of the weld, the local excess height and curvature. The grinding head has poor fit and is prone to trajectory deviation and local suspension, which in turn leads to missed grinding, over-grinding and uneven grinding in some areas. (2) The process parameters were not adaptively allocated based on the local geometric parameters and defect conditions of the weld. The uniform grinding depth, feed speed and contact pressure were used, which made it impossible to focus on the defect section and automatically skip the qualified section. There was a lot of ineffective processing and the processing was less targeted and efficient. (3) The lack of accurate three-dimensional morphology modeling of weld and automatic identification and positioning of defect sections makes it impossible to obtain the actual grinding position and defect distribution of weld. The grinding position guidance lacks accurate data support, making it difficult to achieve targeted grinding. (4) There is no real-time feedback and closed-loop correction of position, contact pressure and post-grinding height during the grinding process. The processing error continues to accumulate, the grinding quality is not stable enough, and the consistency and reliability of batch processing cannot be guaranteed. Summary of the Invention

[0004] This invention provides a method for guiding the flexible conformal grinding position of weld seams in cylindrical shells to overcome the above-mentioned technical problems.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: A method for guiding the flexible conformal grinding position of weld seams in a cylindrical shell, comprising the following steps: S1. Collect the original weld surface image and weld 3D contour data of the weld area, and perform preprocessing to obtain the corrected weld surface image and the corrected weld 3D contour point set; S2. Based on the corrected weld surface image and combined with the weld region segmentation algorithm, the weld body region mask is extracted, and the weld body region mask is mapped to the corrected weld three-dimensional contour point set to obtain the weld three-dimensional point set, thereby generating the weld three-dimensional surface model. Based on the three-dimensional surface model of the weld, the local geometric parameters of the weld are calculated, and the local geometric parameters of the weld are compared with a preset threshold to obtain the three-dimensional geometric anomaly result. The local geometric parameters of the weld include the local weld reinforcement height, the local weld width, and the degree of surface undulation. Image anomaly information is obtained based on the corrected weld surface image, and the image anomaly information is fused with the three-dimensional geometric anomaly results to generate a list of defect segments containing the location, type and severity of defects. S3. Obtain the weld centerline based on the weld three-dimensional point set, establish a weld local coordinate system based on the weld three-dimensional surface model and the weld centerline, and then construct a grinding head target posture matrix to ensure that the grinding head always fits the weld surface. S4. Based on the weld centerline, perform spline fitting to obtain a smooth grinding trajectory baseline. Combine the grinding trajectory baseline and the local weld reinforcement to calculate the normal compensation amount. Based on the normal compensation amount, compensate the grinding trajectory baseline to obtain the actual conformal grinding trajectory. S5. Divide the weld area according to the local geometric parameters of the weld and the list of defect sections, and adaptively allocate process parameters; S6. The actual conformal grinding trajectory, the target posture matrix of the grinding head, and the process parameters are jointly optimized to generate control commands for the actuator. The grinding head is driven to perform grinding operations according to the control commands for the actuator, thereby achieving precise guidance of the grinding position.

[0006] Furthermore, in S2, the processing formula for extracting the weld body region mask based on the corrected weld surface image and combined with the weld region segmentation algorithm is as follows: ; in, Masking for the weld body area; Operator for segmenting the weld area; The formula for mapping the mask of the weld body region to the set of points on the corrected weld three-dimensional contour is as follows: ; in, For the three-dimensional point set of the weld; This is a projection mapping from 3D points to the image plane; Local surface fitting is performed on the three-dimensional point set of the weld to generate a three-dimensional surface model of the weld. The processing formula is as follows: ; in, A three-dimensional surface model of the weld; For local surface fitting operators; The local geometric parameters of the weld, calculated based on the three-dimensional surface model of the weld, include: ; in, Position of arc length Local weld reinforcement at the location; The height of the weld surface; The reference surface height of the base material; ; in, Position of arc length Local width of the weld at the location; This is the left boundary point; This is the right boundary point; ; in, Position of arc length The degree of surface undulation of the weld at the location; This represents the number of points involved in the calculation within a local area. For the first j The height value of each point; This represents the average height of the local area. The calculated local weld reinforcement height, local width, and surface undulation degree are compared with preset thresholds. The specific judgment logic is as follows: If the local residual height exceeds the target residual height range, it is judged as an abnormal residual height; If the width of a part exceeds the standard width range, it is judged as a width abnormality; If the surface undulation exceeds the allowable fluctuation threshold, it is judged as an abnormal surface morphology; If any of the above criteria is exceeded, the location will be marked as a three-dimensional geometric anomaly. Image anomaly information is obtained based on the corrected weld surface image, and the image anomaly information is fused with the three-dimensional geometric anomaly results to generate a list of defect segments containing the location, type and severity of defects. The first in the list of defective sections n Each defective segment is represented as follows: ; in, This indicates the starting arc length position of the defective section; This indicates the location of the terminating arc length of the defective section; Defect type; This indicates the severity of the defect.

[0007] Further, in S3, the specific steps for obtaining the weld centerline based on the weld three-dimensional point set and establishing the weld local coordinate system based on the weld three-dimensional surface model and the weld centerline include: The weld centerline is obtained based on the three-dimensional point set of the weld. The local tangential, normal, and secondary normal directions are calculated based on the three-dimensional surface model of the weld and the weld centerline. Specific steps include: Discretely sample the three-dimensional point set of the weld along the weld extension direction, and establish a local cross-sectional point set at each sampling position; Calculate the local center point of each local section point set, and connect all local center points in sequence to obtain the weld centerline; No. m Local center point The calculation formula is: ; in, Let m be the set of points on the local cross section. For the first i The weighting coefficients of each point; weld centerline Represented as: ; in, This refers to the weld arc length parameter; This is the total arc length of the weld. Based on the three-dimensional surface model of the weld, the local normal direction at each sampling position of the weld centerline is calculated; The local tangential direction is calculated based on adjacent local center points, and then the local secondary normal direction is calculated from the local tangential direction and the local normal direction. Arc length position Local tangential direction at the location Represented as: ; Arc length position Local subnormal direction Represented as: ; in, It is a local normal direction unit vector; A local coordinate system for the weld seam is established based on the local center point, local tangential direction, local normal direction, and local secondary normal direction to determine the weld seam orientation, grinding reference, and grinding head posture. The arc length position is also considered. Local coordinate system of weld at the location Represented as: .

[0008] Further, in S4, spline fitting is performed based on the weld centerline to obtain a smooth grinding trajectory baseline. The normal compensation amount is calculated by combining the grinding trajectory baseline and the local weld reinforcement. The specific steps for compensating the grinding trajectory baseline based on the normal compensation amount to obtain the actual conformal grinding trajectory include: Based on the weld centerline, spline fitting is performed on the discrete points of the weld centerline to obtain the grinding trajectory baseline, as shown in the formula: ; in, This serves as the reference line for the grinding trajectory. The parameters are for the grinding trajectory baseline and are related to the weld arc length parameters. One-to-one correspondence; For the first One control point; These are cubic spline basis functions; The curvature of the grinding trajectory baseline is obtained based on the aforementioned baseline, and the formula is as follows: ; in, Curvature of the grinding trajectory baseline; It is the first derivative; It is the second derivative; Based on the curvature of the grinding trajectory baseline and the local excess height of the weld, the normal compensation amount is calculated using the following formula: ; in, This is the normal compensation amount; Based on the normal bias; The remaining height adjustment coefficient; This refers to the local excess height of the weld. The target is high; This is the curvature adjustment coefficient; The grinding trajectory baseline is compensated based on the normal compensation amount to obtain the actual conformal grinding trajectory, which is expressed as: ; in, This represents the actual conformal grinding trajectory; Trajectory parameters The amount of compensation in the secondary normal direction at the location; Trajectory parameters The local normal direction unit vector at; Trajectory parameters The local binormal direction unit vector at that location; in, ; ; in, This refers to the local lateral offset of the weld. This is the distance from the weld centerline to the left boundary. This is the distance from the weld centerline to the right boundary. This is the secondary normal compensation coefficient.

[0009] Furthermore, the specific steps for constructing the grinding head target attitude matrix to ensure that the grinding head always conforms to the weld surface include: Based on the local coordinate system of the weld, the local tangential direction, local normal direction, and local secondary normal direction are extracted at each sampling position of the grinding trajectory baseline. A target attitude matrix for the grinding head, used to ensure that the grinding head always conforms to the weld surface, is constructed, represented as: ; ; ; ; in, This is the grinding feed direction; It is a unit vector in the local tangential direction; The lateral attitude direction, i.e., the local binormal direction, is represented by a unit vector. The grinding contact direction is the local normal direction unit vector.

[0010] Furthermore, in S5, the specific steps of dividing the weld region according to the local geometric parameters of the weld and the list of defect sections, and adaptively allocating process parameters include: Based on the local geometric parameters of the weld and the list of defective sections, the overall anomaly level is calculated, thereby dividing the weld area into key grinding sections, regular grinding sections, and qualified skip sections. Process parameters for different sections are adaptively allocated, including: Expanding the defect severity in the defect segment list along the weld arc length direction yields a defect severity function, expressed as: ; in, For the first n The severity of each defective segment; These are the starting and ending arc lengths of the nth defect segment, respectively; Based on the local weld reinforcement height, local weld width, and weld surface undulation, and combined with the defect severity function, the comprehensive anomaly degree is calculated and expressed as follows: ; in, This is the normalized residual height deviation; This is the normalized width deviation; To determine the severity of the normalization defect; To normalize the degree of surface undulation; , , , These are the weighting coefficients, and ; Based on the overall degree of anomaly, the weld area is divided along the arc length into key grinding sections, regular grinding sections, and acceptable skipped sections, including: When arc length The overall degree of abnormality Less than the set comprehensive anomaly threshold And the local excess height of the weld Remaining height of the target The absolute value of the deviation is less than the allowable deviation threshold of the residual height. If the time is right, then it is a valid skip section; When arc length The overall degree of abnormality Less than the set comprehensive anomaly threshold And the local excess height of the weld Remaining height of the target The absolute value of the deviation is greater than or equal to the allowable deviation threshold of the residual height. At this time, it is the conventional grinding section; When arc length The overall degree of abnormality Greater than or equal to the set comprehensive anomaly level threshold At that time, it becomes the key grinding section; Based on the actual conformal grinding trajectory, the grinding depth, feed rate, and contact pressure are assigned to each trajectory position, wherein: Grinding depth Represented as: ; in, This refers to the grinding depth. Basic grinding depth; This is the grinding depth adjustment coefficient; These are the minimum and maximum values ​​of the grinding depth, respectively; feed rate Represented as: ; in, Base feed rate; This is the feed rate adjustment coefficient; These are the minimum and maximum feed rates, respectively. Contact pressure Represented as: ; in, Based on contact pressure; This refers to the contact pressure adjustment coefficient. These are the minimum and maximum values ​​of the contact pressure, respectively.

[0011] Furthermore, in S6, the specific steps for jointly optimizing the actual conformal grinding trajectory, the grinding head target posture matrix, and process parameters to generate actuator control commands include: The joint optimization objective function for jointly optimizing the actual conformal grinding trajectory, the target attitude matrix of the grinding head, and the process parameters is defined as follows: ; ; in, To jointly optimize the objective function; , , These are the (k+1)th, (k)th, and (k-1)th actual grinding trajectory points, respectively. The angles of adjacent attitude changes; and These are the feed rates at the (k+1)th and kth positions, respectively; and These represent the grinding depths at positions k+1 and k, respectively. and These are the contact pressures at the (k+1)th and kth positions, respectively; , , , These are the weighting coefficients; and This represents the target attitude matrix of the grinding head at adjacent positions; Represents the matrix trace operation; This is the reference length for the smoothing term of the actual conformal grinding trajectory; The reference angle for adjacent attitude change terms; The reference speed for the feed rate variation term; This is the reference depth for the grinding depth variation term; The reference pressure for the contact pressure variation term; Solving the joint optimization objective function yields the optimized actual grinding trajectory, optimized grinding head target attitude matrix, optimized grinding depth, optimized feed rate, and optimized contact pressure. The optimized results are discretely sampled according to the control cycle, and the joint variables of the actuator are solved based on the discrete sampling results to generate actuator control commands, wherein: The actuator joint variable is represented as: ; in, The function is the inverse kinematics solution; The actuator control command is represented as: ; in, This is the actuator control command for the kth control cycle.

[0012] Furthermore, the flexible conformal grinding position guidance method for cylindrical shell weld seams also includes: During the grinding operation, feedback data is collected synchronously, and the process error is calculated based on the feedback data. It is determined whether the process error exceeds the preset threshold. If so, a local grinding correction process is executed until all process errors meet the accuracy requirements. Otherwise, the section of weld is judged to be qualified for grinding, and the current grinding operation ends.

[0013] Furthermore, the specific steps for collecting feedback data and calculating process errors based on the feedback data include: Collect and provide feedback on actual position, feedback contact pressure, and measured residual height after grinding; Based on feedback data, the local normal deviation, local tangential deviation, residual height error, and contact pressure error are calculated, where: The formula for calculating the local normal deviation is: ; in, To provide feedback on the actual location; It is a local normal direction unit vector; The formula for calculating local tangential deviation is: ; in, It is a unit vector in the local tangential direction; The formula for calculating the residual height error is: ; in, The measured remaining height after grinding; The target is high; The formula for calculating contact pressure error is: ; in, To provide feedback on contact pressure; Target contact pressure; The localized repair and correction process includes: The formula for calculating the localized grinding correction amount is: ; in, Normal correction gain; Tangential correction gain; Gain for correcting contact pressure error; The corrected actual grinding trajectory points are calculated based on the aforementioned local grinding correction amount, using the following formula: ; The formula for calculating the corrected grinding depth is: ; in, Adjust the gain for grinding depth; These are the minimum and maximum values ​​of the grinding depth, respectively; The corrected feed rate is calculated using the following formula: ; in, Adjust the gain for feed rate; These are the minimum and maximum feed rates, respectively. The corrected contact pressure is calculated using the following formula: ; in, Gain correction for contact pressure; These are the minimum and maximum values ​​of the contact pressure, respectively. Until all process errors meet the accuracy requirements, that is: ; in, This is the local normal deviation threshold; This is the local tangential deviation threshold; The residual height error threshold; The contact pressure error threshold; Based on the corrected actual grinding trajectory, grinding depth and feed rate, the actuator control commands are regenerated to drive the grinding head to perform the re-grinding operation.

[0014] Beneficial Effects: This invention generates a 3D surface model of the weld seam based on the fitting of a 3D point set, achieving quantification of local geometric parameters and image anomaly fusion, forming a list of defect sections including defect location, type, and severity, thus improving the comprehensiveness and accuracy of defect detection. A local coordinate system for the weld seam is constructed based on the weld centerline and the 3D surface model, clarifying the weld seam orientation and grinding reference, providing a stable, conforming directional reference for subsequent trajectory and attitude control. A normal compensation amount is introduced based on the spline fitting of the weld centerline, forming an actual grinding trajectory conforming to the curvature changes of the cylindrical shell weld seam, avoiding trajectory deviation and local suspension, and ensuring continuous contact of the grinding head. The comprehensive anomaly degree is calculated based on the local geometric parameters of the weld seam and the list of defect sections, thereby dividing the weld seam area into key grinding sections, regular grinding sections, and qualified skip sections, and adaptively allocating process parameters to achieve centralized processing of abnormal sections and automatic skipping of qualified sections, improving processing targeting. Real-time data collection and feedback during grinding, and dynamic local grinding correction, effectively suppresses over-grinding and under-grinding, improving processing stability and final consistency. Compared to conventional methods with fixed trajectories and parameters, this invention significantly improves the overall grinding efficiency and processing consistency of the curved weld seam of the cylindrical shell, and better adapts to complex morphology and deviation characteristics. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a flowchart of the flexible conformal grinding position guidance method for the weld seam of the cylindrical shell in this invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] This embodiment provides a method for guiding the flexible conformal grinding position of weld seams in cylindrical shells, such as... Figure 1 As shown, the specific steps include: S1. Collect the original weld surface image and weld 3D contour data of the weld area, and perform preprocessing to obtain the corrected weld surface image and the corrected weld 3D contour point set; Specifically, in this embodiment, an industrial camera and a three-dimensional contour sensor are arranged in the area of ​​the weld seam to be ground on the cylindrical shell to simultaneously acquire the original weld seam surface image and the original three-dimensional contour data of the same weld seam area.

[0018] In a specific embodiment, preprocessing of the original weld surface image and weld three-dimensional contour data includes: The original weld surface image is denoised, brightness normalized, and distortion corrected to obtain the corrected weld surface image. The processing formula is as follows: ; in, Image of the original weld surface; To correct the weld surface image; Image preprocessing operators include denoising, brightness normalization, and distortion correction; The original weld 3D contour data is subjected to coordinate transformation, outlier removal, smoothing, and filtering to obtain the corrected weld 3D contour point set. The processing formulas include: ; ; in, In the sensor coordinate system, the first i Three-dimensional points; The first in the workpiece coordinate system i Three-dimensional points; This is the coordinate transformation matrix from the sensor coordinate system to the workpiece coordinate system; To correct the three-dimensional contour point set of the weld; Point cloud preprocessing operators include outlier removal, smoothing, and filtering.

[0019] S2. Based on the corrected weld surface image and combined with the weld region segmentation algorithm, the weld body region mask is extracted. The weld body region mask is mapped onto the corrected weld three-dimensional contour point set to obtain the weld three-dimensional point set. By performing local surface fitting on the weld three-dimensional point set, a weld three-dimensional surface model is generated. Based on the three-dimensional surface model of the weld, the local geometric parameters of the weld are calculated, and the local geometric parameters of the weld are compared with a preset threshold to obtain the three-dimensional geometric anomaly result. The local geometric parameters of the weld include the local weld reinforcement height, the local weld width, and the degree of surface undulation. In a specific embodiment, the processing formula for extracting the weld body region mask based on the corrected weld surface image and combined with the weld region segmentation algorithm is as follows: ; in, Masking for the weld body area; Operator for segmenting the weld area; The formula for mapping the mask of the weld body region to the set of points on the corrected weld three-dimensional contour is as follows: ; in, For the three-dimensional point set of the weld; This is a projection mapping from 3D points to the image plane; Local surface fitting is performed on the three-dimensional point set of the weld to generate a three-dimensional surface model of the weld. The processing formula is as follows: ; in, A three-dimensional surface model of the weld; For local surface fitting operators; The local geometric parameters of the weld, calculated based on the three-dimensional surface model of the weld, include: ; in, Position of arc length Local weld reinforcement at the location; The height of the weld surface; The reference surface height of the base material; ; in, Position of arc length Local width of the weld at the location; This is the left boundary point; This is the right boundary point; ; in, Position of arc length The degree of surface undulation of the weld at the location; This represents the number of points involved in the calculation within a local area. For the first j The height value of each point; This represents the average height of the local area. Specifically, the calculated local weld reinforcement height, local width, and surface undulation degree are compared with preset thresholds, and the specific judgment logic is as follows: If the local residual height exceeds the target residual height range, it is judged as an abnormal residual height. If the width of a part exceeds the standard width range, it is judged as a width abnormality; If the surface undulation exceeds the allowable fluctuation threshold, it is judged as an abnormal surface morphology; If any of the above conditions are exceeded, the location will be marked as a three-dimensional geometric anomaly.

[0020] Image anomaly information is obtained based on the corrected weld surface image, and the image anomaly information is fused with the three-dimensional geometric anomaly results to generate a list of defect segments containing the location, type and severity of defects. Specifically, grayscale, texture, and gradient anomaly detection are performed on the surface image of the corrected weld to obtain image anomaly information.

[0021] Specifically, the first in the list of defective sections n Each defective segment is represented as follows: ; in, This indicates the starting arc length position of the defective section; This indicates the location of the terminating arc length of the defective section; Defect type; This indicates the severity of the defect.

[0022] S3. Obtain the weld centerline based on the weld three-dimensional point set, establish a weld local coordinate system based on the weld three-dimensional surface model and the weld centerline, and then construct a grinding head target posture matrix to ensure that the grinding head always fits the weld surface. In a specific embodiment, S3, the steps of obtaining the weld centerline based on the weld three-dimensional point set and establishing the weld local coordinate system based on the weld three-dimensional surface model and the weld centerline include: The weld centerline is obtained based on the three-dimensional point set of the weld. The local tangential, normal, and secondary normal directions are calculated based on the three-dimensional surface model of the weld and the weld centerline. Specific steps include: Discretely sample the three-dimensional point set of the weld along the weld extension direction, and establish a local cross-sectional point set at each sampling position; Calculate the local center point of each local section point set, and connect all local center points in sequence to obtain the weld centerline; Specifically, no. m Local center point The calculation formula is: ; in, Let m be the set of points on the local cross section. For the first i The weighting coefficients of each point; weld centerline Represented as: ; in, This refers to the weld arc length parameter; This is the total arc length of the weld. Based on the three-dimensional surface model of the weld, the local normal direction at each sampling position of the weld centerline is calculated; The local tangential direction is calculated based on the adjacent local center points, and then the local subnormal direction is calculated from the local tangential direction and the local normal direction.

[0023] Specifically, arc length position Local tangential direction at the location Represented as: ; Arc length position Local subnormal direction Represented as: ; in, It is a local normal direction unit vector; Specifically, a local coordinate system for the weld is established based on the local center point, local tangential direction, local normal direction, and local secondary normal direction to determine the weld direction, grinding reference, and grinding head posture direction.

[0024] Specifically, arc length position Local coordinate system of weld at the location Represented as: .

[0025] S4. Based on the weld centerline, perform spline fitting to obtain a smooth grinding trajectory baseline. Combine the grinding trajectory baseline and the local weld reinforcement to calculate the normal compensation amount. Based on the normal compensation amount, compensate the grinding trajectory baseline to obtain the actual conformal grinding trajectory. In a specific embodiment, in step S4, spline fitting is performed based on the weld centerline to obtain a smooth grinding trajectory baseline. The normal compensation amount is calculated by combining the grinding trajectory baseline and the local weld reinforcement. The specific steps for compensating the grinding trajectory baseline based on the normal compensation amount to obtain the actual conformal grinding trajectory include: Based on the weld centerline, spline fitting is performed on the discrete points of the weld centerline to obtain the grinding trajectory baseline, as shown in the formula: ; in, This serves as the reference line for the grinding trajectory. The parameters are for the grinding trajectory baseline and are related to the weld arc length parameters. One-to-one correspondence; For the first One control point; These are cubic spline basis functions; The curvature of the grinding trajectory baseline is obtained based on the aforementioned baseline, and the formula is as follows: ; in, Curvature of the grinding trajectory baseline; It is the first derivative; It is the second derivative; Based on the curvature of the grinding trajectory baseline and the local excess height of the weld, the normal compensation amount is calculated using the following formula: ; in, This is the normal compensation amount; Based on the normal bias; The remaining height adjustment coefficient; This refers to the local excess height of the weld. The target is high; This is the curvature adjustment coefficient; The grinding trajectory baseline is compensated based on the normal compensation amount to obtain the actual conformal grinding trajectory, which is expressed as: ; in, This represents the actual conformal grinding trajectory; Trajectory parameters The amount of compensation in the secondary normal direction at the location; Trajectory parameters The local normal direction unit vector at; Trajectory parameters The local binormal direction unit vector at that location; in, ; ; in, This refers to the local lateral offset of the weld. This is the distance from the weld centerline to the left boundary. This is the distance from the weld centerline to the right boundary. For the secondary normal compensation coefficient; Based on the local coordinate system of the weld, the local tangential direction, local normal direction, and local secondary normal direction are extracted at each sampling position of the grinding trajectory baseline. Based on the tangential, normal, and secondary normal directions of the weld local coordinate system, a grinding head target attitude matrix is ​​constructed to ensure that the grinding head always conforms to the weld surface, denoted as: ; ; ; ; in, This is the grinding feed direction; It is a unit vector in the local tangential direction; The lateral attitude direction, i.e., the local binormal direction, is represented by a unit vector. The grinding contact direction is the local normal direction unit vector.

[0026] Specifically, this embodiment can generate an actual grinding trajectory and a grinding head target posture matrix that match the curved surface weld of the cylindrical shell based on the weld centerline, the local coordinate system of the weld, and the local height variation of the weld. This improves the ability of the grinding head to fit the weld surface, and allows the grinding position and grinding posture to be dynamically adjusted according to the changes in the weld geometry, reducing problems such as local suspension, trajectory deviation, and uneven grinding caused by surface changes.

[0027] S5. Divide the weld area according to the local geometric parameters of the weld and the list of defect sections, and adaptively allocate process parameters; In a specific embodiment, S5, the specific steps of dividing the weld area according to the weld local geometric parameters and the defect section list, and adaptively allocating process parameters, include: Based on the local geometric parameters of the weld and the list of defective sections, the overall anomaly level is calculated, thereby dividing the weld area into key grinding sections, regular grinding sections, and qualified skip sections. Process parameters for different sections are adaptively allocated, including: Expanding the defect severity in the defect segment list along the weld arc length direction yields a defect severity function, expressed as: ; in, For the first n The severity of each defective segment; These are the starting and ending arc lengths of the nth defect segment, respectively; specifically, when If so, then the maximum severity value of the corresponding segment is taken; if If it does not belong to any defect segment, then Based on the local weld reinforcement height, local weld width, and weld surface undulation, and combined with the defect severity function, the comprehensive anomaly degree is calculated and expressed as follows: ; in, This is the normalized residual height deviation; This is the normalized width deviation; To determine the severity of the normalization defect; To normalize the degree of surface undulation; , , , These are the weighting coefficients, and ; Based on the overall degree of anomaly, the weld area is divided along the arc length into key grinding sections, regular grinding sections, and acceptable skipped sections, including: When arc length The overall degree of abnormality Less than the set comprehensive anomaly threshold And the local excess height of the weld Remaining height of the target The absolute value of the deviation is less than the allowable deviation threshold of the residual height. If the time is right, then it is a valid skip section; When arc length The overall degree of abnormality Less than the set comprehensive anomaly threshold And the local excess height of the weld Remaining height of the target The absolute value of the deviation is greater than or equal to the allowable deviation threshold of the residual height. At this time, it is the conventional grinding section; When arc length The overall degree of abnormality Greater than or equal to the set comprehensive anomaly level threshold At that time, it becomes the key grinding section.

[0028] Based on the actual conformal grinding trajectory, the grinding depth, feed rate, and contact pressure are assigned to each trajectory position, wherein: Grinding depth Represented as: ; in, This refers to the grinding depth. Basic grinding depth; This is the grinding depth adjustment coefficient; These are the upper and lower limits of the grinding depth; feed rate Represented as: ; in, Base feed rate; This is the feed rate adjustment coefficient; These are the upper and lower limits of the feed rate; Contact pressure Represented as: ; in, Based on contact pressure; This refers to the contact pressure adjustment coefficient. These are the upper and lower limits of the contact pressure.

[0029] Specifically, this embodiment maps the local geometric parameters of the weld to the list of defect sections in a unified manner to a comprehensive degree of abnormality. Based on the comprehensive degree of abnormality, the weld is segmented into key grinding sections, regular grinding sections, and qualified skip sections. The corresponding grinding depth, feed rate, and contact pressure are then allocated accordingly to achieve adaptive allocation of process parameters and control of qualified section skipping. This improves the targeting of processing, reduces ineffective grinding, and balances processing quality and processing efficiency.

[0030] S6. The actual conformal grinding trajectory, the target posture matrix of the grinding head, and the process parameters are jointly optimized to generate control commands for the actuator. The grinding head is driven to perform grinding operations according to the control commands for the actuator, thereby achieving precise guidance of the grinding position.

[0031] In a specific embodiment, S6 involves the following steps: jointly optimizing the actual conformal grinding trajectory, the grinding head target posture matrix, and process parameters to generate actuator control commands. The joint optimization objective function for jointly optimizing the actual conformal grinding trajectory, the target attitude matrix of the grinding head, and the process parameters is defined as follows: ; ; in, To jointly optimize the objective function; , , These are the (k+1)th, (k)th, and (k-1)th actual grinding trajectory points, respectively. The angles of adjacent attitude changes; and These are the feed rates at the (k+1)th and kth positions, respectively; and These represent the grinding depths at positions k+1 and k, respectively. and These are the contact pressures at the (k+1)th and kth positions, respectively; , , , These are the weighting coefficients; and This represents the target attitude matrix of the grinding head at adjacent positions; Represents the matrix trace operation; This is the reference length for the smoothing term of the actual conformal grinding trajectory; The reference angle for adjacent attitude change terms; The reference speed for the feed rate variation term; This is the reference depth for the grinding depth variation term; The reference pressure for the contact pressure variation term; Specifically, to avoid the inconsistency in dimensions of the trajectory smoothing term, attitude change term, feed rate change term, grinding depth change term, and contact pressure change term, which prevents them from being directly added, each term is normalized using its corresponding reference scale, so that each term is transformed into a dimensionless evaluation term. Then, a joint optimization objective function is constructed by weighting and summing the terms using dimensionless weight coefficients.

[0032] Specifically, this embodiment can jointly optimize the actual grinding trajectory, the grinding head target posture matrix, and process parameters, and perform local closed-loop corrections during the grinding process based on the feedback actual position, feedback contact pressure, and measured residual height after grinding, thereby reducing the risk of local over-grinding and under-grinding, and improving the stability of the grinding process and the consistency of the final processing.

[0033] Solving the joint optimization objective function yields the optimized actual grinding trajectory, optimized grinding head target attitude matrix, optimized grinding depth, optimized feed rate, and optimized contact pressure. The optimized results are discretely sampled according to the control cycle, and the joint variables of the actuator are solved based on the discrete sampling results to generate actuator control commands, wherein: The actuator joint variable is represented as: ; in, The function is the inverse kinematics solution; The actuator control command is represented as: ; in, This is the actuator control command for the kth control cycle.

[0034] This embodiment also includes: during the grinding operation, synchronously collecting feedback data, calculating process error based on the feedback data, determining whether the process error exceeds a preset threshold, and if so, executing a local grinding correction process until all process errors meet the accuracy requirements; otherwise, determining that the section of weld seam is qualified for grinding and ending the current grinding operation.

[0035] In a specific embodiment, the specific steps for collecting feedback data and calculating process errors based on the feedback data include: Collect and provide feedback on actual position, feedback contact pressure, and measured residual height after grinding; Based on feedback data, the local normal deviation, local tangential deviation, residual height error, and contact pressure error are calculated, where: The formula for calculating the local normal deviation is: ; in, To provide feedback on the actual location; It is a local normal direction unit vector; The formula for calculating local tangential deviation is: ; in, It is a unit vector in the local tangential direction; The formula for calculating the residual height error is: ; in, The measured remaining height after grinding; The target is high; The formula for calculating contact pressure error is: ; in, To provide feedback on contact pressure; Target contact pressure; The localized repair and correction process includes: The formula for calculating the localized grinding correction amount is: ; in, Normal correction gain; Tangential correction gain; Gain for correcting contact pressure error; The corrected actual grinding trajectory points are calculated based on the aforementioned local grinding correction amount, using the following formula: ; The formula for calculating the corrected grinding depth is: ; in, Adjust the gain for grinding depth; These are the minimum and maximum values ​​of the grinding depth, respectively; The corrected feed rate is calculated using the following formula: ; in, Adjust the gain for feed rate; These are the minimum and maximum feed rates, respectively. Specifically, in the feed rate correction formula, an adaptive adjustment is achieved by subtracting a correction term proportional to the absolute value of the residual height error, thus ensuring that "the larger the error, the lower the feed rate." clip The function is used to limit the corrected speed within the minimum / maximum feed rate range allowed by the process, preventing the speed from being too low or too high.

[0036] The corrected contact pressure is calculated using the following formula: ; in, Gain correction for contact pressure; These are the minimum and maximum values ​​of the contact pressure, respectively. Until all process errors meet the accuracy requirements, that is: ; in, This is the local normal deviation threshold; This is the local tangential deviation threshold; The residual height error threshold; The contact pressure error threshold; Based on the corrected actual grinding trajectory, grinding depth and feed rate, the actuator control commands are regenerated to drive the grinding head to perform the re-grinding operation.

[0037] Specifically, this embodiment calculates the local grinding correction amount for out-of-tolerance positions and corrects the actual grinding trajectory, grinding depth and feed rate to ensure that the grinding position, attitude and parameters are always accurate, avoid missed grinding and over-grinding, and ensure the stability and accuracy of position guidance.

[0038] Specifically, the flexible conformal grinding position guidance method for cylindrical shell welds proposed in this embodiment achieves the following technical effects through full-process control: multi-source data acquisition and unified coordinate mapping, weld 3D morphology modeling and defect segment identification, weld local coordinate system construction, conformal grinding trajectory and attitude generation, adaptive allocation of process parameters, and execution feedback closed-loop correction: (1) Based on the three-dimensional surface model of the weld, a local coordinate system is constructed and the conformal grinding trajectory and posture are generated so that the grinding head can continuously fit along the curvature change of the weld surface of the cylindrical shell, avoiding trajectory deviation and local suspension; (2) Based on the local geometric parameters and defect information of the weld, the comprehensive degree of abnormality is calculated, and the key grinding of abnormal sections and the automatic skipping of qualified sections are realized, which improves the processing targeting. (3) By jointly optimizing the trajectory, attitude and process parameters, the consistency among the three is ensured, and the processing defects caused by the mismatch between attitude and trajectory are avoided; (4) Local grinding correction is implemented based on the position, contact pressure and residual height feedback during the grinding process, which effectively reduces the risk of over-grinding and under-grinding and improves the processing stability; (5) Compared with conventional grinding schemes with fixed trajectory and fixed parameters, this embodiment significantly improves the overall grinding efficiency and processing consistency, and can better adapt to the complex morphology and deviation characteristics of the curved surface weld of the cylindrical shell.

[0039] Specifically, the method proposed in this embodiment can be applied to post-weld surface repair scenarios for pressure vessels, tubular components, cylindrical structural parts, etc.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions 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 guiding the position of flexible conformal grinding of weld seams in cylindrical shells, characterized in that, The specific steps include: S1. Collect the original weld surface image and weld 3D contour data of the weld area, and perform preprocessing to obtain the corrected weld surface image and the corrected weld 3D contour point set; S2. Based on the corrected weld surface image and combined with the weld region segmentation algorithm, the weld body region mask is extracted, and the weld body region mask is mapped to the corrected weld three-dimensional contour point set to obtain the weld three-dimensional point set, thereby generating the weld three-dimensional surface model. Based on the three-dimensional surface model of the weld, the local geometric parameters of the weld are calculated, and the local geometric parameters of the weld are compared with a preset threshold to obtain the three-dimensional geometric anomaly result. The local geometric parameters of the weld include the local weld reinforcement height, the local weld width, and the degree of surface undulation. Based on the corrected weld surface image, image anomaly information is obtained, and the image anomaly information is fused with the three-dimensional geometric anomaly results to generate a list of defect segments containing the location, type and severity of defects. S3. Obtain the weld centerline based on the weld three-dimensional point set, establish a weld local coordinate system based on the weld three-dimensional surface model and the weld centerline, and then construct a grinding head target posture matrix to ensure that the grinding head always fits the weld surface. S4. Based on the weld centerline, perform spline fitting to obtain a smooth grinding trajectory baseline. Combine the grinding trajectory baseline and the local weld reinforcement to calculate the normal compensation amount. Based on the normal compensation amount, compensate the grinding trajectory baseline to obtain the actual conformal grinding trajectory. S5. Divide the weld area according to the local geometric parameters of the weld and the list of defect sections, and adaptively allocate process parameters; S6. The actual conformal grinding trajectory, the target posture matrix of the grinding head, and the process parameters are jointly optimized to generate control commands for the actuator. The grinding head is driven to perform grinding operations according to the control commands for the actuator, thereby achieving precise guidance of the grinding position.

2. The method for guiding the flexible conformal grinding position of the weld seam of a cylindrical shell according to claim 1, characterized in that, In S2, the processing formula for extracting the weld body region mask based on the corrected weld surface image and combined with the weld region segmentation algorithm is as follows: ； in, Masking for the weld body area; Operator for segmenting the weld area; The formula for mapping the mask of the weld body region to the set of points on the corrected weld three-dimensional contour is as follows: ； in, For the three-dimensional point set of the weld; This is a projection mapping from 3D points to the image plane; Local surface fitting is performed on the three-dimensional point set of the weld to generate a three-dimensional surface model of the weld. The processing formula is as follows: ； in, A three-dimensional surface model of the weld; For local surface fitting operators; The local geometric parameters of the weld, calculated based on the three-dimensional surface model of the weld, include: ； in, Position of arc length Local excess weld height at the location; The height of the weld surface; The reference surface height of the base material; ； in, Position of arc length Local width of the weld at the location; This is the left boundary point; This is the right boundary point; ； in, Position of arc length The degree of surface undulation of the weld at the location; This represents the number of points involved in the calculation within a local area. For the first j The height value of each point; This represents the average height of the local area. The calculated local weld reinforcement height, local width, and surface undulation degree are compared with preset thresholds. The specific judgment logic is as follows: If the local residual height exceeds the target residual height range, it is judged as an abnormal residual height; If the width of a part exceeds the standard width range, it is judged as a width abnormality; If the surface undulation exceeds the allowable fluctuation threshold, it is judged as an abnormal surface morphology; If any of the above criteria is exceeded, the location will be marked as a three-dimensional geometric anomaly. Based on the corrected weld surface image, image anomaly information is obtained, and the image anomaly information is fused with the three-dimensional geometric anomaly results to generate a list of defect segments containing the location, type and severity of defects. The first in the list of defective sections n Each defective segment is represented as: ； in, This indicates the starting arc length position of the defective section; This indicates the location of the terminating arc length of the defective section; Defect type; This indicates the severity of the defect.

3. The method for guiding the flexible conformal grinding position of the weld seam of a cylindrical shell according to claim 2, characterized in that, In S3, the specific steps for obtaining the weld centerline based on the weld three-dimensional point set and establishing the weld local coordinate system based on the weld three-dimensional surface model and the weld centerline include: The weld centerline is obtained based on the three-dimensional point set of the weld. The local tangential, normal, and secondary normal directions are calculated based on the three-dimensional surface model of the weld and the weld centerline. Specific steps include: Discretely sample the three-dimensional point set of the weld along the weld extension direction, and establish a local cross-sectional point set at each sampling position; Calculate the local center point of each local section point set, and connect all local center points in sequence to obtain the weld centerline; No. m Local center point The calculation formula is: ； in, Let m be the set of points on the local cross section. For the first i The weighting coefficients of each point; weld centerline Represented as: ； in, This refers to the weld arc length parameter; This is the total arc length of the weld. Based on the three-dimensional surface model of the weld, the local normal direction at each sampling position of the weld centerline is calculated; The local tangential direction is calculated based on adjacent local center points, and then the local secondary normal direction is calculated from the local tangential direction and the local normal direction. Arc length position Local tangential direction at the location Represented as: ； Arc length position Local subnormal direction Represented as: ； in, It is a local normal direction unit vector; A local coordinate system for the weld seam is established based on the local center point, local tangential direction, local normal direction, and local secondary normal direction to determine the weld seam orientation, grinding reference, and grinding head posture. The arc length position is also considered. Local coordinate system of weld at the location Represented as: 。 4. The method for guiding the flexible conformal grinding position of the weld seam of a cylindrical shell according to claim 3, characterized in that, In S4, spline fitting is performed based on the weld centerline to obtain a smooth grinding trajectory baseline. The normal compensation amount is calculated by combining the grinding trajectory baseline and the local weld reinforcement. The specific steps for compensating the grinding trajectory baseline based on the normal compensation amount to obtain the actual conformal grinding trajectory include: Based on the weld centerline, spline fitting is performed on the discrete points of the weld centerline to obtain the grinding trajectory baseline, as shown in the formula: ； in, This serves as the reference line for the grinding trajectory. The parameters are for the grinding trajectory baseline and are related to the weld arc length parameters. One-to-one correspondence; For the first One control point; These are cubic spline basis functions; The curvature of the grinding trajectory baseline is obtained based on the aforementioned baseline, and the formula is as follows: ； in, Curvature of the grinding trajectory baseline; It is the first derivative; It is the second derivative; Based on the curvature of the grinding trajectory baseline and the local excess height of the weld, the normal compensation amount is calculated using the following formula: ； in, This is the normal compensation amount; Based on the normal bias; The remaining height adjustment coefficient; This refers to the local reinforcement of the weld. The target is high; This is the curvature adjustment coefficient; The grinding trajectory baseline is compensated based on the normal compensation amount to obtain the actual conformal grinding trajectory, which is expressed as: ； in, This represents the actual conformal grinding trajectory; Trajectory parameters The amount of compensation in the secondary normal direction at the location; Trajectory parameters The local normal direction unit vector at; Trajectory parameters The local binormal direction unit vector at that location; in, ； ； in, This refers to the local lateral offset of the weld. This is the distance from the weld centerline to the left boundary. This is the distance from the weld centerline to the right boundary. This is the secondary normal compensation coefficient.

5. The method for guiding the flexible conformal grinding position of the weld seam of a cylindrical shell according to claim 4, characterized in that, The specific steps for constructing the grinding head target attitude matrix to ensure that the grinding head always conforms to the weld surface include: Based on the local coordinate system of the weld, the local tangential direction, local normal direction, and local secondary normal direction are extracted at each sampling position of the grinding trajectory baseline. A target attitude matrix for the grinding head, used to ensure that the grinding head always conforms to the weld surface, is constructed, represented as: ； ； ； ； in, This is the grinding feed direction; It is a unit vector in the local tangential direction; The lateral attitude direction, i.e., the local binormal direction, is represented by a unit vector. The grinding contact direction is the local normal direction unit vector.

6. The method for guiding the flexible conformal grinding position of the weld seam of a cylindrical shell according to claim 5, characterized in that, In S5, the specific steps for dividing the weld area according to the local geometric parameters of the weld and the list of defect sections, and adaptively allocating process parameters include: Based on the local geometric parameters of the weld and the list of defective sections, the overall anomaly level is calculated, thereby dividing the weld area into key grinding sections, regular grinding sections, and qualified skip sections. Process parameters for different sections are adaptively allocated, including: Expanding the defect severity in the defect segment list along the weld arc length direction yields a defect severity function, expressed as: ； in, For the first n The severity of each defective segment; These are the starting and ending arc lengths of the nth defect segment, respectively; Based on the local weld reinforcement height, local weld width, and weld surface undulation, and combined with the defect severity function, the comprehensive anomaly degree is calculated and expressed as follows: ； in, This is the normalized residual height deviation; This is the normalized width deviation; To determine the severity of the normalization defect; To normalize the degree of surface undulation; , , , These are the weighting coefficients, and ; Based on the overall degree of anomaly, the weld area is divided along the arc length into key grinding sections, regular grinding sections, and acceptable skipped sections, including: When arc length The overall degree of abnormality Less than the set comprehensive anomaly threshold And the local excess height of the weld Remaining height of the target The absolute value of the deviation is less than the allowable deviation threshold of the residual height. If the time is right, then it is a valid skip section; When arc length The overall degree of abnormality Less than the set comprehensive anomaly threshold And the local excess height of the weld Remaining height of the target The absolute value of the deviation is greater than or equal to the allowable deviation threshold of the residual height. At this time, it is the conventional grinding section; When arc length The overall degree of abnormality Greater than or equal to the set comprehensive anomaly threshold At that time, it becomes the key grinding section; Based on the actual conformal grinding trajectory, the grinding depth, feed rate, and contact pressure are assigned to each trajectory position, wherein: Grinding depth Represented as: ； in, This refers to the grinding depth. Basic grinding depth; This is the grinding depth adjustment coefficient; These are the minimum and maximum values ​​of the grinding depth, respectively; feed rate Represented as: ； in, Base feed rate; This is the feed rate adjustment coefficient; These are the minimum and maximum feed rates, respectively. Contact pressure Represented as: ； in, Based on contact pressure; This refers to the contact pressure adjustment coefficient. These are the minimum and maximum values ​​of the contact pressure, respectively.

7. The method for guiding the flexible conformal grinding position of the weld seam of a cylindrical shell according to claim 6, characterized in that, In S6, the specific steps for jointly optimizing the actual conformal grinding trajectory, the target posture matrix of the grinding head, and the process parameters to generate control commands for the actuator include: The joint optimization objective function for jointly optimizing the actual conformal grinding trajectory, the target attitude matrix of the grinding head, and the process parameters is defined as follows: ； ； in, To jointly optimize the objective function; , , These are the (k+1)th, (k)th, and (k-1)th actual grinding trajectory points, respectively. The angles of adjacent attitude changes; and These are the feed rates at the (k+1)th and kth positions, respectively; and These represent the grinding depths at positions k+1 and k, respectively. and These are the contact pressures at the (k+1)th and kth positions, respectively; , , , These are the weighting coefficients; and This represents the target attitude matrix of the grinding head at adjacent positions; Represents the matrix trace operation; This is the reference length for the smoothing term of the actual conformal grinding trajectory; The reference angle for adjacent attitude change terms; The reference speed for the feed rate variation term; This is the reference depth for the grinding depth variation term; The reference pressure for the contact pressure variation term; Solving the joint optimization objective function yields the optimized actual grinding trajectory, optimized grinding head target attitude matrix, optimized grinding depth, optimized feed rate, and optimized contact pressure. The optimized results are discretely sampled according to the control cycle, and the joint variables of the actuator are solved based on the discrete sampling results to generate actuator control commands, wherein: The actuator joint variable is represented as: ； in, The function is the inverse kinematics solution; The actuator control command is represented as: ； in, This is the actuator control command for the kth control cycle.

8. The method for guiding the flexible conformal grinding position of the weld seam of a cylindrical shell according to claim 7, characterized in that, Also includes: During the grinding operation, feedback data is collected synchronously, and the process error is calculated based on the feedback data. It is determined whether the process error exceeds the preset threshold. If so, a local grinding correction process is executed until all process errors meet the accuracy requirements. Otherwise, the section of weld is judged to be qualified for grinding, and the current grinding operation ends.

9. The method for guiding the flexible conformal grinding position of the weld seam of a cylindrical shell according to claim 8, characterized in that, The specific steps for collecting feedback data and calculating process errors based on the feedback data include: Collect and provide feedback on actual position, feedback contact pressure, and measured residual height after grinding; Based on feedback data, the local normal deviation, local tangential deviation, residual height error, and contact pressure error are calculated, among which: The formula for calculating the local normal deviation is: ； in, To provide feedback on the actual location; It is a local normal direction unit vector; The formula for calculating local tangential deviation is: ； in, It is a unit vector in the local tangential direction; The formula for calculating the residual height error is: ； in, The measured remaining height after grinding; The target is high; The formula for calculating contact pressure error is: ； in, To provide feedback on contact pressure; Target contact pressure; The localized repair and correction process includes: The formula for calculating the localized grinding correction amount is: ； in, Normal correction gain; Tangential correction gain; Gain for correcting contact pressure error; The corrected actual grinding trajectory points are calculated based on the aforementioned local grinding correction amount, using the following formula: ； The formula for calculating the corrected grinding depth is: ； in, Adjust the gain for grinding depth; These are the minimum and maximum values ​​of the grinding depth, respectively; The corrected feed rate is calculated using the following formula: ； in, Adjust the gain for feed rate; These are the minimum and maximum feed rates, respectively. The corrected contact pressure is calculated using the following formula: ； in, Gain correction for contact pressure; These are the minimum and maximum values ​​of the contact pressure, respectively. Until all process errors meet the accuracy requirements, that is: ； in, This is the local normal deviation threshold; This is the local tangential deviation threshold; The residual height error threshold; The contact pressure error threshold; Based on the corrected actual grinding trajectory, grinding depth and feed rate, the actuator control commands are regenerated to drive the grinding head to perform the re-grinding operation.

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