A method for correcting an initial profile error of a shaping tool, a medium, and an electronic device

Abstract

The present application relates to the technical field of ultra-precision machining, and particularly relates to a method for correcting initial profile error of a dressing tool, a medium and an electronic device. The method is realized in three steps: generating an initial motion path according to an ideal profile and a target profile, performing first dressing to obtain an actual profile of a copying grinding wheel, and inversely calculating the actual profile of the dressing grinding wheel based on the principle of envelope reversibility. The core advantage lies in that discrete processing is adopted, the maximum value of each discrete point is calculated, the real profile can be accurately inversely calculated when there is error in the initial profile, the error can be effectively compensated, the dressing precision is improved, and the error problem caused by the fact that the profile of the dressing grinding wheel cannot be directly measured in the traditional method is solved. The scheme does not need to additionally configure high-priced measuring devices such as laser sensors, uses existing systems and workpiece measurement results, inversely calculates through a mathematical model, reduces the cost of devices, simplifies the operation process, automatically completes the whole process from data acquisition to profile reconstruction, improves the efficiency, and reduces the labor cost and technical threshold.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ultra-precision machining, in particular to a method for correcting initial profile error of a dressing tool, a medium and an electronic device. BACKGROUND

[0002] The existing dressing techniques for grinding wheels mainly include online electrolytic dressing, water jet dressing, laser dressing and mechanical dressing:

[0003] (1) Online electrolytic dressing: suitable for metal bond grinding wheels, high-precision dressing is achieved through electrolysis, but it has strong limitations and is only suitable for conductive materials.

[0004] (2) Water jet dressing: tangential dressing is achieved by using abrasive water jet, which can process various bond grinding wheels, but the equipment is complex and the dressing accuracy is limited by the stability of the water jet.

[0005] (3) Laser dressing: precise dressing is achieved by laser beam, but the device is difficult to integrate and the cost is high.

[0006] (4) Mechanical dressing: direct enveloping dressing is used by using dressing grinding wheels, which is simple to operate and low in cost, and is the most widely used method.

[0007] Problems existing in the existing mechanical dressing technology for grinding wheels and existing solutions:

[0008] (1) The initial profile error of the dressing tool seriously affects the dressing accuracy, and the existing solutions can be divided into two categories:

[0009] a) The machining error of the workpiece is measured, the error is added to the designed surface type, and the dressing tool motion path is recalculated for compensation; however, when the actual dressing tool profile is not an ideal circle, it is difficult to calculate the normal vector of the dressing tool surface, and it is difficult to compensate in this way.

[0010] b) The initial profile of the dressing tool is measured before calculating the dressing tool motion trajectory, which is used to calculate the dressing tool motion path; but in some machining scenarios, the accurate initial profile of the dressing tool is difficult to be measured on the machine due to the space limitation of the machine tool. SUMMARY

[0011] In view of one of the above technical problems, the technical solution adopted by the present application is:

[0012] According to one aspect of the present application, a method for correcting the initial profile error of a dressing tool is provided, the method comprising the following steps:

[0013] S1.1: generating an initial dressing wheel motion path according to the ideal dressing wheel profile and the target profile of the copying wheel;

[0014] S1.2: Perform the first shaping based on the initial shaping grinding wheel movement path to obtain the actual contour of the shaping grinding wheel after shaping;

[0015] S1.3: Based on the initial movement path of the shaping grinding wheel and the actual contour of the contouring grinding wheel, the actual contour of the shaping grinding wheel is generated by inversion based on the principle of envelope reversibility.

[0016] S1.3 includes:

[0017] The profile of the shaping grinding wheel is divided into multiple discrete points at equal intervals along the X-axis;

[0018] For any x-coordinate t Discrete points at which the true profile height f of the shaping grinding wheel is located. at (x) t The following conditions must be met:

[0019] ;

[0020] Among them, f at (x) t ): The true contour of the shaping grinding wheel on the x-axis t The ordinate of the location;

[0021] f a (x): True profile function of the contour grinding wheel; f a (x tp +x t ) is the profile grinding wheel at position x tp +x t The actual profile height at that location;

[0022] z tp =f tp (x tp ): The relative motion path function between the profile grinding wheel and the contour grinding wheel; z tp For the shaping grinding wheel at path point x tp The vertical displacement of the point relative to the reference.

[0023] For all possible x tp Take the maximum value.

[0024] According to a second aspect of the present invention, a non-transitory computer-readable storage medium is provided, which stores a computer program that, when executed by a processor, implements the above-described method for correcting the initial contour error of a shaping tool.

[0025] According to a third aspect of the present application, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method for correcting initial profile error of a dressing tool when executing the computer program.

[0026] The present application has at least one of the following beneficial effects:

[0027] The present technical solution realizes fine analysis of the dressing wheel profile through discretization processing. For each discrete point x t , the method calculates the maximum value of f tp (x a +x tp )+z t by traversing all possible x tp values. This process ensures that the real profile of the dressing wheel can be accurately reconstructed even if there is an error in the initial profile of the dressing wheel. The traditional method cannot directly measure the actual profile of the dressing wheel, resulting in a large dressing error. However, the present application accurately reconstructs the real profile of the dressing wheel through the envelope reversibility principle, effectively compensates for the initial profile error, and significantly improves the dressing accuracy of the copying wheel. This solves the error problem caused by the inability to directly measure the actual profile of the dressing wheel in the traditional method.

[0028] By using the technical solution of the present application, the real profile of the dressing wheel can be obtained without additional high-cost measurement equipment such as laser sensors or probes. Compared with the traditional dressing method, the present solution fully utilizes the existing grinding system and workpiece replication measurement results, and reconstructs the actual profile of the dressing wheel through mathematical model inversion calculation. This method not only reduces the equipment investment cost, but also simplifies the operation process, so there is no need for complex on-machine measurement work. In addition, this method can automatically complete all steps from data acquisition to profile reconstruction, significantly improving work efficiency, reducing labor cost and technical threshold, so that operators without deep professional knowledge can also successfully perform related operations. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0030] Figure 1 A flowchart of a method for correcting initial profile error of a dressing tool is provided for the embodiments of the present application.

[0031] Figure 2 A principle diagram of mechanical dressing of a grinding wheel is provided for the embodiments of the present application.

[0032] Figure 3 This is a schematic diagram illustrating the inversion of the actual contour of a contoured grinding wheel from the actual contour of the contoured grinding wheel, provided in an embodiment of the present invention.

[0033] Figure 4 A flowchart of a method for correcting the profile of a dressing grinding wheel based on non-uniform wear provided in an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram showing the positional relationship between the dressing wheel and the conforming wheel during mechanical dressing of grinding wheels, provided in an embodiment of the present invention.

[0035] Figure 6 Provided for embodiments of the present invention Figure 5 Schematic diagram for predicting wear of medium grinding wheels;

[0036] Figure 7 A schematic diagram illustrating two methods for obtaining contour errors in this invention, provided for embodiments of the invention;

[0037] Figure 8 A schematic diagram of the target contour of the contour grinding wheel is provided for the embodiment of the present invention to verify its effectiveness;

[0038] Figure 9 A schematic diagram illustrating the effect of profile grinding wheel modification compensation in an embodiment for verifying the effectiveness of the present invention. Detailed Implementation

[0039] 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, and 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.

[0040] like Figure 2 As shown, in mechanical dressing of grinding wheels, the contour error of the dressing wheel directly affects the contour error of the copying wheel, and thus affects the surface shape error of the final workpiece. To reduce the contour error of the copying wheel, it is necessary to obtain the contour error Δf of the dressing wheel. t (u) quantification data, and correct the motion path according to the actual contour. The modification wheel error that affects the final profile accuracy of the profile grinding wheel mainly comes from two aspects: (1) initial profile error, that is, the shape deviation that exists in the manufacturing process of the modification grinding wheel; (2) profile error introduced by non-uniform wear during the modification process. Figure 2 In the diagram, (a) is a schematic diagram of the parallel envelope shaping of the profile grinding wheel; (b) is a schematic diagram of the contour error of the actual shaping grinding wheel; and (c) is a schematic diagram of the contour error of the profile grinding wheel caused by the contour error of the shaping grinding wheel.

[0041] As a possible embodiment of the present application, as shown in Figure 1 Fig. 1, a method for correcting the initial profile error of a dressing tool is provided, which is used to obtain the real profile of a dressing wheel according to the initial profile error of the dressing wheel, and the method comprises the following steps:

[0042] S1.1: generating an initial dressing wheel motion path according to the ideal dressing wheel profile and the target profile of the copying wheel.

[0043] Specifically, S1.1 comprises:

[0044] S1.11: discretizing the target profile of the copying wheel along the X-axis into a plurality of target points.

[0045] S1.12: for each target point, solving the contact point on the ideal dressing wheel profile in contact with it based on the envelope forming principle, and calculating the corresponding dressing wheel pose.

[0046] S1.13: generating an initial dressing wheel motion path according to the dressing wheel poses corresponding to all target points.

[0047] In this embodiment, a circular profile butterfly dressing wheel can be selected as the dressing tool, and the front end cross-sectional profile thereof is defined as the dressing wheel profile; the front end cross-sectional profile of the copying wheel is defined as the workpiece profile. Based on the target profile of the copying wheel and the ideal profile of the dressing wheel, the motion path of the dressing wheel in the envelope dressing process can be generated.

[0048] Let the profile of the copying wheel be f d (x), the profile of the dressing wheel be f t (u), and the motion path of the dressing wheel be z tp =f tp (x tp )。According to the envelope forming principle, when the dressing wheel forms the profile of the copying wheel by trajectory interpolation motion, for any contact point (x, f d (x)) on the profile of the copying wheel, the motion path of the dressing wheel needs to satisfy the following geometric conditions:

[0049] (1).

[0050] Through the condition, the motion path coordinates (x tp (x), z tp (x)) of the dressing wheel corresponding to the contact point can be determined.

[0051] Taking the profile dressing of a concave aspheric copying wheel as an example, the above process is explained:

[0052] The profile equation of the copying wheel is , wherein k is the aspheric coefficient, a parameter controlling the curvature degree of the curved surface, and R is the radius of curvature.

[0053] The ideal modified grinding wheel profile is a circular arc, and its equation is ; wherein Rt is the radius of the circular arc of the modified grinding wheel .

[0054] Substituting the above parameters into the envelope condition formula (formula 1) can obtain the motion path coordinates of the modified grinding wheel relative to the profiling grinding wheel, and the motion path coordinates satisfy the following conditions: .

[0055] S1.2: Perform the first modification based on the initial motion path of the modified grinding wheel, and obtain the actual profile of the profiling grinding wheel after modification.

[0056] Specifically, S1.2 includes:

[0057] S1.21: Based on the initial motion path of the modified grinding wheel, control the modified grinding wheel to perform the first modification on the profiling grinding wheel to the reprinted workpiece. The profiling grinding wheel reprinted workpiece can be a calcium fluoride workpiece.

[0058] After having the initial motion path of the modified grinding wheel, the modified grinding wheel can be controlled to perform grinding motion according to the path, and then the profile to be ground on the profiling grinding wheel is reprinted to the calcium fluoride workpiece, so as to facilitate subsequent profile measurement by using a three-dimensional profilometer.

[0059] S1.22: Measure the cross-sectional profile of the profiling grinding wheel reprinted workpiece after modification is completed by using a three-dimensional profilometer, and indirectly obtain the actual profile of the profiling grinding wheel.

[0060] S1.3: According to the initial motion path of the modified grinding wheel and the actual profile of the profiling grinding wheel, the actual profile of the modified grinding wheel is inversely generated based on the envelope reversibility principle.

[0061] In the actual modification process, the real profile of the modified grinding wheel has an error △f t (u), the ideal profile is f t (u), and the actual profile f at (u)=△f t (u)+f t (u). The error will cause the profile of the profiling grinding wheel generated by envelope to deviate. According to the envelope reversibility principle: under the premise that the actual profile of the profiling grinding wheel and the relative motion path of the modified grinding wheel and the profiling grinding wheel are known, the real profile of the modified grinding wheel can be obtained by inversion.

[0062] Therefore, S1.3 includes:

[0063] S1.31: Disperse the profile of the modified grinding wheel into a plurality of discrete points along the X-axis at equal intervals.

[0064] S1.32: For any abscissa x tThe height f of the real profile of the modified grinding wheel at the corresponding position point can be obtained according to the envelope reversibility principle at (x t ), f at (x t ) satisfy the following conditions:

[0065] .

[0066] wherein f at (x t ): the ordinate of the real profile of the modified grinding wheel at the abscissa x t .

[0067] f a (x): the real profile function of the copying grinding wheel. f a (x tp +x t ) is the actual profile height of the copying grinding wheel at the position x tp +x t .

[0068] z tp =f tp (x tp ): the relative motion path function between the modified grinding wheel and the copying grinding wheel. z tp is the vertical displacement of the modified grinding wheel at the path point x tp relative to the reference.

[0069] : the maximum value for all possible x tp .

[0070] Based on the envelope reversibility principle: from the perspective of the copying grinding wheel, the envelope formed by the profile of the modified grinding wheel and its motion path is the profile of the modified copying grinding wheel; conversely, if the actual profile of the modified copying grinding wheel obtained by actual modification and the relative motion path of the modified grinding wheel and the copying grinding wheel are known, the envelope formed by the profile motion of the copying grinding wheel can also reflect the real profile of the modified grinding wheel when the modification is completed (as shown in Figure 3 ).

[0071] For any discrete point, the vertical displacement of the modified grinding wheel at different positions x tp in the motion path is z tp ==f tp (x tp ), and the actual profile height of the copying grinding wheel at the composite position x tp +x t is f a (x tp +x t ). According to the envelope principle, the three satisfy the relationship: That is, the profile height of the profile grinding wheel is determined by the maximum value of the superposition of the actual profile of the profile grinding wheel and the displacement of the motion path.

[0072] In this step, we iterate through all possible x. tp Value, calculate f a (x tp +x t )+z tp The maximum value of x can uniquely determine x. t The actual profile height of the shaping grinding wheel at a given location. This extreme value solution method can eliminate the interference of irrelevant points in the motion path, accurately capture the actual contact state between the shaping grinding wheel and the conforming grinding wheel, and thus realize the inversion of the profile value of a single discrete point.

[0073] By discretizing the profile of the shaping grinding wheel into a sufficient number of points (such as equidistant discretization) and performing the above inversion process on each point, a complete set of discrete points representing the true profile of the shaping grinding wheel can be obtained. A continuous profile curve can then be generated through curve fitting (as in step S1.4).

[0074] In this embodiment, a theoretical framework is established based on the principle of envelope reversibility. By combining discretization point-by-point solution and extreme value analysis, accurate inversion of the profile value of the shaping grinding wheel is achieved. This method does not require direct measurement of the shaping grinding wheel profile; it can be inverted using only the actual profile and motion path of the shaped grinding wheel, effectively solving the error problem caused by measurement limitations in traditional methods.

[0075] S1.4: Perform curve fitting on the discrete point coordinates obtained in S1.3 to generate the corrected true profile of the shaping grinding wheel.

[0076] S1.5: Based on the actual contour of the shaping grinding wheel obtained in S1.4, correct the initial shaping grinding wheel motion path and generate the compensated shaping grinding wheel motion path.

[0077] On the one hand, S1.5 can be implemented according to the following steps:

[0078] S1.53: Based on the actual contour of the shaping grinding wheel obtained in S1.4, correct the initial shaping grinding wheel motion path and generate the compensated second shaping grinding wheel motion path.

[0079] This example obtains the actual profile data of the dressing wheel by calibrating the initial profile error of the dressing wheel, such as... Figure 7 As shown in (a) to (c) in the figure. Based on this actual contour value, the motion trajectory of the profile grinding wheel is adjusted and compensated to generate a more precise motion path. Under this path control, the contour shape of the profile grinding wheel obtained by the profile grinding wheel is closer to the target shape. For specific effects, please refer to... Figure 9 (a) and (b) in the text. Figure 9In the diagram, (a) is a schematic diagram of the uncompensated profile error of the profile grinding wheel; (b) is a schematic diagram of the profile error of the profile grinding wheel after compensation for the initial profile error of the modified grinding wheel; and (c) is a schematic diagram of the profile error of the profile grinding wheel after compensation for the initial profile error of the modified grinding wheel and compensation for non-uniform wear.

[0080] On the other hand, S1.5 can also be implemented according to the following steps:

[0081] S1.51: The actual profile of the dressing wheel obtained based on S1.4 is further corrected by the non-uniform wear amount of the dressing wheel to obtain the target grinding profile of the dressing wheel, such as... Figure 7 As shown in (a) to (d) in the diagram.

[0082] S1.52: Based on the target grinding profile, correct the initial dressing wheel motion path and generate the compensated first dressing wheel motion path.

[0083] In addition to the initial profile error, the profile error caused by uneven wear during the dressing process of the dressing wheel also affects the dressing accuracy of the profile grinding wheel. Therefore, when correcting the initial dressing wheel's motion path in S1.5, both the initial profile error and the profile error caused by uneven wear can be included simultaneously to obtain the true profile of the dressing wheel. Based on this profile, the motion trajectory of the dressing wheel can be adjusted to obtain a more accurate motion path.

[0084] S1.6: Based on the compensated movement path of the profile grinding wheel, control the profile grinding wheel to perform grinding motion in order to compensate and modify the profile grinding wheel.

[0085] In the dressing process of profile grinding wheels, the abrasive grain size of the dressing wheel is usually larger than that of the profile grinding wheel. While removing material from the profile grinding wheel, the larger abrasive grains of the dressing wheel also undergo wear, breakage, or detachment due to stress, resulting in changes to the outer contour of the dressing wheel formed by the rotation of the abrasive grains. During the enveloping dressing process, the amount of material removed from the profile grinding wheel varies in different areas of the dressing wheel contour, causing its wear to exhibit non-uniform characteristics. The wear amount of the dressing wheel is mainly affected by geometric parameters, material parameters, and process parameters. When the dressing wheel and profile grinding wheel are selected and the process parameters remain constant, the wear amount is only related to the geometric interference (grinding contact interference) between the two during the grinding motion.

[0086] As another possible embodiment of the present invention, such as Figure 4 As shown, a method for correcting the profile of a dressing grinding wheel based on non-uniform wear is also provided. In this embodiment, to accurately predict this non-uniform wear behavior, a wear calculation scheme based on the line indentation number is proposed. The method includes the following steps:

[0087] S2.1: Discretize the profile of the modified grinding wheel along the rotation axis direction to obtain a plurality of discrete points.

[0088] Specifically, S2.1 includes:

[0089] S2.11: Discretize the actual profile of the modified grinding wheel after the error correction according to the initial profile along the rotation axis direction (such as the X-axis direction in Figure 5 ) to obtain a plurality of discrete points.

[0090] Specifically, as shown in Figure 6 and Figure 7 , first discretize the profile of the modified grinding wheel on the XOZ section into a series of key points. For each discrete point, calculate its corresponding linear aggressiveness coefficient Aggr t according to its kinematics and contact geometry in the envelope modification process. The coefficient comprehensively reflects the dynamic interaction intensity of the contact area where the point is located, and its physical meaning is: the ratio of the normal relative velocity to the tangential relative velocity per unit contact length. The larger the value is, the more intense the material removal is in the area, and the more serious the wear is. Figure 6 In , (a) is a local section view on the XOZ plane; (b) is a local section view on the YOZ plane. Figure 7 In , (a) is a schematic diagram of the initial state calculated by the discretization method of the motion path of the modified grinding wheel; (b) is a schematic diagram of calculating the minimum distance to obtain the motion path point of the modified grinding wheel and the contact point; (c) is a schematic diagram of actually calculating the profile of the modified grinding wheel according to the profile of the profile grinding wheel; (d) is a schematic diagram of predicting the profile change caused by non-uniform wear of the modified grinding wheel.

[0091] Of course, all the discrete point coordinates obtained in S1.3 can also be directly used in this step.

[0092] S2.2: For any discrete point, obtain its linear aggressiveness coefficient. The linear aggressiveness coefficient Aggr at j of the discrete point (x at , y j , z t ) satisfies the following conditions: ′j

[0093] .

[0094] where q = v t / v d is the speed ratio, v t and v d are the linear velocities of the modified grinding wheel and the profile grinding wheel respectively. r eq =r t / r d is the radius ratio, r tand r d Here, α represents the radius of rotation of the dressing wheel and the conforming wheel, respectively. s The indentation depth is calculated based on Hertzian contact theory. θ at j For discrete points (x) at j ,z at j The tangent angle of ).

[0095] Specifically, the principle behind this step is as follows: Figure 5 and Figure 6 As shown, the definition is as follows Figure 5 The Cartesian coordinate system shown has both the profile grinding wheel and the contour grinding wheel having their rotation axes parallel to the X-axis and located in the XOZ plane, with rotation radii r and r, respectively. t and r d The rotational speeds are respectively w t and w d .

[0096] From the perspective of a shaping grinding wheel, when a certain point (x) on its surface... t y t , z t When in contact with the profile grinding wheel, the relative velocity v of the profile grinding wheel is... d Under the assumption of small displacement, it can be approximated as: The corresponding normal vector is: Where θ is the point (x, y) of the shaping grinding wheel on the XOZ plane. t y t , z t The tangent angle, such as Figure 6 As shown in (a) of the diagram. According to the invasiveness theory, the number of point invasivenesses... Defined as the normal relative velocity component V at the contact point N relative velocity component V in the tangential direction T The ratio:

[0097] ;

[0098] In the actual reshaping process, such as Figure 6 As shown in (b), when a point on the dressing wheel contacts the conforming wheel, a contact line is formed along the Y-axis. The contact points on this line continuously wear. Since the axial feed rate of the dressing wheel is much smaller than its circumferential rate, the contact line can be approximated as parallel to the YOZ plane. The length of the contact line, i.e., the width L of the contact area, is calculated using Hertzian contact theory as follows: .

[0099] Line invasiveness number Agggr tAggr is the integral average of the line invasiveness number along the contact line, that is, the average value of the invasiveness number of all points on the contact line, and is used to comprehensively reflect the wear trend of the entire contact area, so Aggr t ’ satisfies the following conditions:

[0100] .

[0101] S2.3: According to the line invasiveness coefficient, the wear amount of each discrete point is calculated. Wherein the discrete point (x at j ,z at j ) corresponds to Δ t j satisfies the following conditions:

[0102] .

[0103] Wherein, N is the number of modified tools, and C is the wear coefficient. The wear coefficient is determined by experiment calibration and is a constant when the process parameters are unchanged.

[0104] The wear amount of any point on the modified grinding wheel profile is positively correlated with the line invasiveness number (that is, the greater the line invasiveness number, the more serious the wear of the point), and in this embodiment, N and C are taken as the corresponding positive correlation coefficients. Wherein N can indicate the cumulative number of wear of the contact point. The wear coefficient C is only related to the process parameters and material parameters, and is irrelevant to the geometric parameters. In the use scenario of the present application, the modified process parameters and the materials of the modified grinding wheel and the profile grinding wheel remain unchanged, and only the influence of the geometric parameters on the wear amount is analyzed, so C is regarded as a constant and is calibrated through experimental data.

[0105] S2.4: According to the wear amount corresponding to the discrete point and the tangent angle at the point, the coordinates of the discrete point after wear are obtained. The discrete point (x at j ,z at j ) corresponds to the coordinates (x at ′j ,z at ′j ) after wear, which satisfies the following conditions:

[0106] .

[0107] Generally, the deformation direction of non-uniform wear is the normal direction of the contact point, so the corresponding position of the point (x t , z t ) on the XOZ section of the modified grinding wheel profile after wear is . By using this method, the non-uniform wear amount of all discrete points on the modified grinding wheel can be predicted, and the profile change of the modified grinding wheel after non-uniform wear can be predicted, such asFigure 6 (a) and Figure 7 As shown in (d) in the figure.

[0108] In the process of ultra-precision profile grinding wheel dressing, to facilitate numerical calculation, the profile of the dressing wheel is usually discretized at equal intervals along the X-axis direction, such as... Figure 7 (a) in the figure. However, this discretization method has the following inherent defects: since the profile of the shaping grinding wheel is usually a non-linear curve (such as a circular arc, non-spherical surface, etc.), the local arc lengths corresponding to the same X-direction spacing are not equal. In the region with large curvature, the actual arc length is much larger than the X-spacing; in the flat region, it is close to the X-spacing.

[0109] More importantly, during the envelope shaping process, a discrete point on the shaping wheel will continuously contact multiple discrete points on the conforming wheel, resulting in cumulative wear. If this cumulative wear (such as the integral sum of the linear intrusion coefficients) is directly assigned to this discrete point, this method of concentrating the total wear over a finite arc length onto a single mathematical point leads to a significantly higher calculation result for local wear, which is particularly pronounced in high curvature regions.

[0110] This problem causes the wear prediction model based on the line intrusion coefficient to fail to accurately reflect the actual evolution process of the profile of the profiled grinding wheel, which in turn affects the accuracy of the subsequent compensation path and limits the further improvement of the profiled grinding wheel's profiled accuracy.

[0111] To address the distortion in wear calculation caused by discretization, another possible embodiment of this invention proposes a wear correction method based on arc length amortization. The core of this method lies in normalizing and averaging the cumulative wear effect according to the actual arc length represented by the discrete points of the grinding wheel, thereby obtaining a wear amount with clear physical meaning and a reasonable spatial distribution.

[0112] Specifically, this method can replace S2.4 in the above embodiment, and the steps of this method are as follows:

[0113] S3.4 Based on the arc length corresponding to the discrete point on the dressing wheel and the total contact arc length corresponding to the discrete point on the contouring wheel, the wear amount corresponding to the discrete point is corrected to generate the corrected wear amount corresponding to the discrete point. Wherein, the discrete point (x... at j ,z at j The corresponding corrected wear amount Δ at j The following conditions must be met:

[0114] .

[0115] Among them, l at jthe local arc length represented by the discrete point (x at j ,z at j ) on the profiled grinding wheel. at j The local arc length is calculated by arc length integration between adjacent discrete points or calculated according to the corresponding horizontal axis range of the arc length and the profile shape of the profiled grinding wheel.

[0116] the total arc length of all contact points corresponding to the discrete point (x at j ,z at j ) on the profiled grinding wheel. The arc length at each contact point can be obtained as follows: according to the actual profile of the profiled grinding wheel and the relative motion trajectory between the profiled grinding wheel and the profiled grinding wheel, a plurality of points on the profiled grinding wheel profile that are in contact with the target profiled grinding wheel profile can be determined. Subsequently, based on the target profiled grinding wheel profile, the arc length at each contact point is further calculated.

[0117] S3.5: According to the correction wear amount corresponding to the discrete point and the tangent angle at the point, the coordinates of the discrete point after wear are obtained. The coordinates (x at j ,z at j ) of the discrete point (x at ′j ,z at ′j ) after wear satisfy the following conditions:

[0118] .

[0119] In this embodiment, the total wear amount is divided by the local arc length corresponding to the discrete point on the profiled grinding wheel profile to obtain the average wear amount per unit arc length, and the average value is taken as the representative wear depth of the discrete point. This correction method not only ensures the consistency of the wear amount in physical dimension (wear amount is length dimension), but also more truly reflects the distribution density of wear in space. This method characterizes the wear amount as the average wear level of all finer discrete points on this segment of arc length, significantly improving the accuracy and robustness of the non-uniform wear prediction model, and providing a reliable basis for subsequent high-precision profiled path compensation.

[0120] S2.5: According to the coordinates of all discrete points after wear, a predicted profiled grinding wheel non-uniform wear profile is generated, as shown in Figure 7 .

[0121] Specifically, S2.5 includes:

[0122] S2.51: Based on the wear coordinates of all discrete points, perform interpolation to generate a discrete point set of the profile of the grinding wheel after grinding. The x-coordinates of any two adjacent discrete points in the discrete point set meet the requirement of a fixed step size Δx.

[0123] S2.6: The profile of the dressing wheel after uneven wear is used as the new dressing wheel profile, and the compensated dressing wheel motion path is generated based on the envelope forming principle.

[0124] The original wear prediction model updates the coordinates based on the different wear amounts and tangent angles at each point, resulting in the updated X-coordinates no longer being evenly distributed. If this non-uniformity is directly used in CNC programming or further envelope calculations, it can lead to problems such as unstable interpolation algorithms, feed rate fluctuations, and sudden changes in axial acceleration, thus affecting the final shaping quality. Therefore, in S2.51, we use interpolation techniques to resample the worn contour into an evenly spaced set of points. This method effectively solves the X-axis non-uniformity problem caused by normal wear displacement, ensuring that the output path maintains both physical accuracy and engineering feasibility. Furthermore, this evenly distributed set of points provides more accurate input for subsequent envelope calculations, avoiding problems such as low contact point search efficiency and increased normal vector calculation errors, thereby ensuring the continuity and consistency of the entire shaping process.

[0125] Compared with the prior art, the present invention has the following advantages:

[0126] 1. Rapid convergence of shaping errors: In a single compensation process, the initial contour error compensation and non-uniform wear contour change compensation of the shaping tool are integrated, resulting in high error convergence efficiency and reduced iteration count.

[0127] 2. Easy to operate and low cost: No additional on-machine measuring equipment (such as laser sensors) is required; it can be achieved using existing grinding systems.

[0128] 3. High versatility: Applicable to various grinding wheels, and can perform contouring grinding wheel dressing for various profiles.

[0129] Specifically, the technical effects of the present invention are illustrated by the following experimental data:

[0130] A 90mm diameter 3000# ceramic-based diamond wheel with a circular arc radius is selected as the dressing wheel, and an 88mm diameter 23000# ceramic-based diamond wheel with a circular arc radius (R) is selected as the contour wheel. The radius of the dressing wheel is 0.08mm. Figure 8 The diagram shows a schematic of the contour of the profile grinding wheel target, which consists of three parts: the effective area, the tangent transition arc, and the extended edge. The effective area contour, with a width of 480 μm, is aspherical, where R = 0.4 mm and k = 0.3.

[0131] Follow the steps specified in the above format example to obtain the following two profile grinding wheel profiles:

[0132] (1) Without any compensation, modify the profile of the profile grinding wheel and replicate the profile of the profile grinding wheel.

[0133] (2) When only performing initial profile error compensation (IPEC) on the actual profile grinding wheel and without considering the profile error caused by non-uniform wear, generate the profile grinding wheel motion path, modify the profile grinding wheel and replicate the profile of the profile grinding wheel.

[0134] (3) After (1), differential wear compensation (DWC) is performed, specifically by predicting the profile of the modified grinding wheel after differential wear using the aforementioned algorithm. Finally, the compensated movement path of the modified grinding wheel is generated from the predicted profile of the modified grinding wheel after differential wear and the profile of the target shaped grinding wheel. The shaped grinding wheel is then modified and the profile of the shaped grinding wheel is replicated and measured.

[0135] The contour error in the effective area after three contour wheel dressing operations is as follows: Figure 9 As shown in (a)-(c) in the figure. The red dashed line represents the contour error corresponding to the original data, which contains high-frequency fluctuations caused by the replication of randomly distributed protruding diamond abrasive grains. The low-frequency components in the error were extracted using an IIR low-pass filter with a cutoff space frequency of 50 1 / mm and a steepness of 0.99, as shown by the blue solid line.

[0136] Without any compensation, the low-frequency profile error PV value of the profile wheel dressing is 355.6 nm, and the RMS value is 100.5 nm.

[0137] When only the initial profile error of the actual profiled grinding wheel is compensated, the low-frequency profile error PV value of the profiled grinding wheel is 196.7 nm and the RMS value is 52.2 nm, which are 44.7% and 48.0% lower than when there is no compensation, respectively.

[0138] With compensation for the initial profile error of the true profiled grinding wheel and compensation for non-uniform wear, the low-frequency profile error PV value of the profiled grinding wheel is 62.3 nm and the RMS value is 11.2 nm, which are 82.5% and 88.9% lower than without any compensation, respectively, and 68.3% and 78.6% lower than with only compensation for the initial profile error of the true profiled grinding wheel.

[0139] These results show that the initial profile error of the modified grinding wheel and the profile error introduced by non-uniform wear have great influence on the modification accuracy of the copying grinding wheel, and the compensation processing based on the above two errors can improve the profile accuracy of the workpiece.

[0140] In addition, although the various steps of the methods in the present disclosure are described in a particular order in the accompanying drawings, this does not require or imply that the steps must be performed in this particular order, or that all of the steps shown must be performed to achieve the desired result. Additionally or alternatively, certain steps can be omitted, multiple steps can be combined into one step, one step can be divided into multiple steps, and the like.

[0141] From the above description of the embodiments, those skilled in the art can easily understand that the example embodiments described herein can be implemented by software, or by software in combination with necessary hardware. Therefore, the technical solutions according to the embodiments of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a U disk, a mobile hard disk, etc.) or a network, and includes a number of instructions to make a computing device (which can be a personal computer, a server, a mobile terminal, or a network device, etc.) execute the methods according to the embodiments of the present disclosure.

[0142] In the example embodiments of the present disclosure, an electronic device capable of implementing the above method is also provided.

[0143] Those skilled in the art can understand that each aspect of the present disclosure can be implemented as a system, a method or a program product. Therefore, each aspect of the present disclosure can be embodied in the form of a complete hardware, a complete software (including firmware, microcode, etc.), or a combination of hardware and software aspects, which can be collectively referred to as "circuitry", "module" or "system".

[0144] The electronic device according to this embodiment of the present disclosure. The electronic device is merely an example, and should not bring any limitation to the functions and use range of the embodiments of the present disclosure.

[0145] The electronic device is in the form of a general computing device. The components of the electronic device can include but are not limited to the above-mentioned at least one processor, the above-mentioned at least one storage, and a bus connecting different system components (including storage and processor).

[0146] The storage stores program code, which can be executed by the processor, so that the processor performs the steps according to various example embodiments of the present disclosure described in the above "example method" section of the specification.

[0147] The storage can include a readable medium in the form of volatile storage such as random access memory (RAM) and / or cache memory, and can further include a non-volatile storage such as read only memory (ROM).

[0148] The storage can also include a program / utility, having a set of program modules, which are configured to carry out the processes of the subject matter described herein, including an operating system, one or more application programs, other program modules, and program data, each or some combination thereof, which may

[0149] The bus can represent one or more of several types of bus structures, including a storage bus or bus controller, a peripheral bus, a graphics bus, a processor or local bus using any of a variety of bus architectures.

[0150] The electronic device can also communicate with one or more external devices such as a keyboard or a pointing device, through an I / O interface. Additionally, the electronic device can communicate with one or more devices that enable a user to interact with the electronic device through an input device or devices 110. The input device(s) 110 can include, for example, a microphone, a camera, a button, a switch, an infrared port, a USB port, a Bluetooth® interface, a memory card slot, a wireless transceiver, and the like. The input device(s) 110 can also include a display device, a speaker, a headphone jack, an antenna, and the like. The input device(s) 110 and / or the output device(s) 112 can include circuitry for handling both audio and visual signals. The electronic device can communicate with one or more networks, such as one or more networks 116, through a network adapter. The networks 116 can include wired or wireless networks that are operated by a service provider that does not have ownership rights in the electronic device. A wireless network can include a network using IEEE 802.11, 802.16, 802.15, or 802.Hhp wireless communication technology. A wired network can include a local area network (LAN), a general wide area network (WAN), and / or a public network such as the Internet. The network adapter can manage and control the caller's connection to the network(s) 116. It should be appreciated that the network adapter can also manage and control connections in which the electronic device is a server system or a client system to other server and client systems in any of the networks 116.

[0151] In the example embodiments of the present disclosure, a computer readable storage medium having stored thereon a program product capable of implementing the method described above is also provided. In some possible implementation manners, each aspect of the present disclosure can also be implemented in the form of a program product, which includes program codes for causing a terminal device to perform the steps described in the above “Example Method” section according to various example embodiments of the present disclosure when the program product is run on the terminal device.

[0152] A program product can take any combination of one or more computer-readable media. The computer-readable media can be a computer-readable storage medium or a computer-readable signal medium. The computer-readable storage medium can be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the above. More specific examples (a non-exhaustive list) of the computer-readable storage medium include an electrical connection having one or more wires, a portable disc, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0153] The computer-readable signal medium can include a computer-readable storage medium that is propagated as a carrier wave in a baseband or propagated as part of a propagated data signal in a carrier, such as a propagated signal. The propagated signal can take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer-readable signal medium can be any computer-readable medium that is not a computer-readable storage medium and that can communicate, propagate, or transport programming for use by or in connection with an instruction execution system, apparatus, or device.

[0154] The program code embodied on the computer-readable media can be transmitted using any appropriate medium, including but not limited to wireless, wired, optical fiber cable, RF, etc., or any suitable combination of the above.

[0155] Program code used to practice the present application can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, C++, or the like, and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computing device, partly on the user's computing device, as a stand-alone software package, partly on the user's computing device and partly on a remote computing device or entirely on the remote computing device or server. In the latter scenario, the remote computing device can be connected to the user's computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computing device, such as through the Internet using an Internet Service Provider. The present application can also be practiced in

[0156] In addition, the flow diagrams illustrate the processes of the example embodiments of the present application, but the processes need not necessarily be executed in the order as shown or in sequential order at all. Further, some processes can be executed in parallel or concurrently with one another. In addition, the processes illustrated in the flow diagrams need not necessarily be executed by the same device or devices, but can be executed by one or more devices in serial, or in parallel, or in some other order, including incrementally.

[0157] It should be noted that, although several modules or units of the devices for action execution are mentioned in the above detailed description, the division into such modules or units is not mandatory. Indeed, according to an embodiment of the present disclosure, the features and functionalities of two or more of the above-described modules or units can be embodied in one module or unit. Conversely, the features and functionalities of one of the above-described modules or units can be further divided into several modules or units.

[0158] The above merely shows the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any changes or replacements within the technical scope disclosed by the present application can be easily conceived by those skilled in the art, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for correcting the initial contour error of a shaping tool, characterized in that, The method includes the following steps: S1.1: Generate the initial motion path of the dressing wheel based on the ideal dressing wheel profile and the target profile of the contouring wheel; S1.2: Perform the first shaping based on the initial shaping grinding wheel movement path to obtain the actual contour of the shaping grinding wheel after shaping; S1.3: Based on the initial movement path of the shaping grinding wheel and the actual contour of the contouring grinding wheel, the actual contour of the shaping grinding wheel is generated by inversion based on the principle of envelope reversibility. S1.3 includes: The profile of the shaping grinding wheel is divided into multiple discrete points at equal intervals along the X-axis; For any x-coordinate t Discrete points at which the true profile height f of the shaping grinding wheel is located. at (x) t The following conditions must be met: ； Among them, f at (x) t ): The true contour of the shaping grinding wheel on the x-axis t The ordinate of the location; f a (x): True profile function of the contour grinding wheel; f a (x tp +x t ) is the profile grinding wheel at position x tp +x t The actual profile height at that location; z tp =f tp (x tp ): The relative motion path function between the profile grinding wheel and the contour grinding wheel; z tp For the shaping grinding wheel at path point x tp The vertical displacement of the point relative to the reference. For all possible x tp Take the maximum value.

2. The method according to claim 1, characterized in that, Following S1.3, it also includes: S1.4: Perform curve fitting on the discrete point coordinates obtained in S1.3 to generate the corrected true profile of the shaping grinding wheel; S1.5: Based on the actual contour of the shaping grinding wheel obtained in S1.4, correct the initial shaping grinding wheel motion path and generate a compensated shaping grinding wheel motion path.

3. The method according to claim 1, characterized in that, S1.2 includes: S1.21: Based on the initial shaping wheel movement path, control the shaping wheel to perform the first shaping on the workpiece copied by the contour wheel; S1.22: Use a 3D profiler to measure the cross-sectional profile of the workpiece after the profile is modified, and indirectly obtain the actual profile of the profile grinding wheel.

4. The method according to claim 2, characterized in that, S1.5 includes: S1.51: The actual profile of the dressing wheel obtained based on S1.4 is corrected again by the non-uniform wear amount of the dressing wheel to obtain the target grinding profile of the dressing wheel. S1.52: Based on the target grinding profile, correct the initial shaping wheel motion path to generate the compensated first shaping wheel motion path.

5. The method according to claim 2, characterized in that, S1.5 includes: S1.53: Based on the true contour of the shaping grinding wheel obtained in S1.4, correct the initial shaping grinding wheel motion path and generate a compensated second shaping grinding wheel motion path.

6. The method according to claim 1, characterized in that, S1.1 includes: S1.11: Discretize the contour of the contour grinding wheel target into multiple target points along the X-axis; S1.12: For each target point, based on the envelope forming principle, solve for the contact point on the ideal shaping wheel profile that contacts it, and calculate the corresponding shaping wheel pose; S1.13: Generate the initial grinding wheel motion path based on the grinding wheel poses corresponding to all target points.

7. The method according to claim 3, characterized in that, The workpiece being replicated by the contour grinding wheel is a calcium fluoride workpiece.

8. The method according to claim 2, characterized in that, Following S1.5, it also includes: S1.6: Based on the compensated movement path of the profile grinding wheel, control the profile grinding wheel to perform grinding motion in order to compensate and modify the profile grinding wheel.

9. A non-transitory computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements a method for correcting the initial contour error of a shaping tool as described in any one of claims 1 to 8.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements a method for correcting the initial contour error of a shaping tool as described in any one of claims 1 to 8.

Images