Methods, equipment, and media for compensating for mold grinding errors based on grinding wheel wear.

Abstract

This invention provides a method, device, and medium for compensating for mold grinding errors based on grinding wheel wear, applicable to the field of machining. The method includes: acquiring a wear image of the grinding wheel to be processed; obtaining the edge contour information of the grinding wheel; determining the vertical wear height H and wear volume V of the grinding wheel; if V > V0, determining the abscissa set U of the mold point cloud; and determining the compensation correction parameter F of the i-th surface point cloud of the optical surface mold to be processed. i According to F i U i The base circle radius R of the optical surface mold to be processed base The compensation correction value Z for the i-th surface point cloud is obtained. i The invention controls a mold correction machine to correct the optical surface mold to be processed. This invention incorporates the wear factor of the grinding wheel into the error compensation process for the optical surface mold, enriching the traditional compensation evaluation indicators for optical surface molds, improving compensation accuracy, and facilitating high-precision machining of optical surface molds.

Description

Technical Field

[0001] This invention relates to the field of machining, and in particular to a method, equipment, and medium for compensating for mold grinding errors based on grinding wheel wear. Background Technology

[0002] With the miniaturization and precision of optical communication products, the demand for high-precision aspherical optical glass lenses is increasing. Aspherical lenses are widely used in aerospace, aviation, astronomy, electronics, and optical communication fields. Aspherical molds, also known as optical curved surface molds, are an important means of lens manufacturing.

[0003] Traditional optical surface mold processing technology suffers from problems such as low precision, inaccurate detection, and difficulty in error elimination. Furthermore, traditional error compensation methods do not take into account the wear of the grinding wheel during the grinding of optical aspherical molds, resulting in poor error compensation accuracy for optical aspherical molds. Summary of the Invention

[0004] To address the aforementioned technical problems, the technical solution adopted by this invention is as follows:

[0005] According to one aspect of this application, a method for compensating for mold grinding errors based on grinding wheel wear is provided, applied to an error compensation system. The error compensation system is communicatively connected to an optical surface mold to be processed and a grinding wheel. The grinding wheel is used to perform grinding processing on the optical surface mold. The method includes the following steps:

[0006] S100. After each grinding process of the optical surface mold to be processed by the grinding wheel, the wear image of the grinding wheel to be processed is obtained.

[0007] S200: Perform edge detection processing on the wear image to be processed to obtain the edge contour information of the grinding wheel;

[0008] S300. Based on the edge contour information, determine the first edge feature point, the second edge feature point, and the third edge feature point; the first edge feature point and the second edge feature point are the left and right endpoints of the cross-sectional curve of the wear surface of the grinding wheel, respectively, and the third edge feature point is the endpoint that is on the same edge of the grinding wheel as the first edge feature point.

[0009] S400. Determine the vertical wear height H of the grinding wheel based on the first edge feature point, the second edge feature point, and the third edge feature point.

[0010] S500. Determine the wear volume V of the grinding wheel based on the vertical wear height H.

[0011] S600. If V > V0, then obtain the abscissa of the surface point cloud of the optical surface mold to be processed in the preset first coordinate system, and obtain the abscissa set of the mold point cloud U = (U1, U2, ..., U...). i ,...,U n ); where i = 1, 2, ..., n; n is the number of point clouds on the surface of the optical surface mold to be processed; U i V0 represents the abscissa of the i-th surface point cloud of the optical surface mold to be processed in the preset first coordinate system; V0 is the preset first wear volume threshold.

[0012] S700, according to U i The grinding wheel's number of grinding passes (T) and radius (R) are used to determine the compensation correction parameter F for the i-th surface point cloud of the optical surface mold to be processed. i ;

[0013] S800, according to F i U i The base circle radius R of the optical surface mold to be processed base The compensation correction value Z of the i-th surface point cloud of the optical surface mold to be processed is obtained. i ;

[0014] S900, according to Z1, Z2, ..., Z i ,...,Z n The mold correction machine controls the correction of the optical surface mold to be processed.

[0015] In one exemplary embodiment of this application, the wear vertical height H of the grinding wheel is determined by the following method:

[0016] S410. Draw the edge profile of the grinding wheel based on the edge profile information;

[0017] S420. Place the edge contour of the grinding wheel in a preset second coordinate system. The coordinates of the first edge feature point in the preset second coordinate system are (x...). A ,y A The coordinates of the second edge feature point in the preset second coordinate system are (x, y). C ,y C The coordinates of the third edge feature point in the preset second coordinate system are (x, y). B ,y B ); where the unit length of the preset second coordinate system is the same as that of the preset first coordinate system;

[0018] S430. Determine the slope k of the straight line between the first edge feature point and the third edge feature point. B -y A ) / (x B -xA );

[0019] S440, Determine the vertical wear height H = (k*x) C +y A -k*x A -y C ) / (1+k 2 ) 1 / 2 .

[0020] In one exemplary embodiment of this application, the wear volume V of the grinding wheel is determined by the following method:

[0021] S510. Based on the increasing numerical values, obtain the abscissa of each coordinate point within the edge contour of the grinding wheel in the preset second coordinate system, and obtain the abscissa set of the grinding wheel X = (x1, x2, ..., x...). j ,...,x m ); where j = 1, 2, ..., m; m is the number of coordinate points of the grinding wheel within the edge contour of the preset second coordinate system; x j Let be the x-coordinate of the j-th coordinate point within the edge contour of the grinding wheel in the preset second coordinate system;

[0022] S520. Determine the wear volume of the grinding wheel.

[0023] In one exemplary embodiment of this application, step S600 further includes:

[0024] S610. If V≤V0, a ​​warning signal is issued and the die grinding error compensation method based on grinding wheel wear is exited.

[0025] In one exemplary embodiment of this application, the compensation correction parameter F i It is determined by the following method:

[0026] S710. Determine the wear slope of the grinding wheel W = d * T + e; where d < 1, e < 1, and d and e are preset wear coefficients;

[0027] S720. Determine the compensation correction parameter F i =W / R*|U i |

[0028] In one exemplary embodiment of this application, the compensation correction value Z i It is determined by the following formula:

[0029] Z i =(U i ) 2 / (R base +((R base )2 -(1+g)*(U i ) 2 ) 1 / 2 )+∑ b a＝2 L a (U i ) a -ΔZ-F i ;

[0030] Where: g < 1, g is the preset compensation coefficient; L a The compensation correction coefficient is ΔZ = Z. (i-1) -Z0, where Z0 is the preset compensation correction threshold and b is the preset power threshold.

[0031] In one exemplary embodiment of this application, step S710 is replaced with:

[0032] S711. If V0 < V ≤ V1, then determine the wear slope W = d1 * T + e1; if V > V1, then determine the wear slope W = d2 * T + e2; where V1 is the preset second wear volume threshold, d1 < d2, e1 > e2, and d1, d2, e1, and e2 are preset wear coefficients.

[0033] In one exemplary embodiment of this application, step S100 further includes:

[0034] S110. If there is a shadow area at the edge of the worn image to be processed, the shadow area is blurred and eliminated, and step S200 is executed.

[0035] According to one aspect of this application, a non-transitory computer-readable storage medium is provided, wherein at least one instruction or at least one program is stored in the storage medium, the at least one instruction or the at least one program being loaded and executed by a processor to implement the aforementioned mold grinding error compensation method based on grinding wheel wear.

[0036] According to one aspect of this application, an electronic device is provided, including a processor and the aforementioned non-transitory computer-readable storage medium.

[0037] The present invention has at least the following beneficial effects:

[0038] This invention compensates for errors in optical surface molds based on the wear factor of grinding wheels. It obtains the edge contour of the grinding wheel by performing edge detection on the measured wear image after in-situ measurement, and uses a slope mutation algorithm to obtain the feature points of the edge contour. The wear volume of the wear area is then calculated. Based on the number of grinding passes, the radius of the grinding wheel, and the base circle radius of the optical surface mold, a compensation correction value is obtained for each point cloud of the optical surface mold. Error compensation is then performed on the corresponding point cloud using each compensation correction value. This invention adds the wear factor of grinding wheels to the error compensation process for optical surface molds, enriching the traditional compensation evaluation indicators for optical surface molds. Compared with traditional compensation methods, it improves the compensation accuracy and facilitates high-precision machining of optical surface molds. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 A flowchart of a mold grinding error compensation method based on grinding wheel wear provided in an embodiment of the present invention;

[0041] Figure 2 A schematic diagram of a mold processing machine provided in an embodiment of the present invention;

[0042] Figure 3 A three-dimensional schematic diagram of the optical surface mold to be processed provided in an embodiment of the present invention;

[0043] Figure 4 A schematic diagram of the processing result of the edge contour information of the wear image to be processed provided in an embodiment of the present invention;

[0044] Figure 5 A schematic diagram illustrating the determination of the first edge feature point, the second edge feature point, and the third edge feature point provided in an embodiment of the present invention;

[0045] Figure 6 (a) is a schematic diagram showing the change of the wear vertical height of the grinding wheel and the grinding cycle provided in the embodiment of the present invention;

[0046] Figure 6 (b) is a schematic diagram showing the change in wear volume and grinding cycle of the grinding wheel provided in the embodiment of the present invention;

[0047] Figure 7 This is a schematic diagram of a compensation path considering grinding wheel wear provided in an embodiment of the present invention;

[0048] Figure 8 This is a schematic diagram of the contour error of the optical surface mold to be processed after grinding compensation under different scenarios provided in the embodiments of the present invention. Detailed Implementation

[0049] 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.

[0050] Ultra-precision machining occupies an irreplaceable position in many cutting-edge technology fields such as advanced optics, aerospace, defense industry, and integrated circuit manufacturing, including laser fusion optical systems, advanced guidance and positioning systems, lidar systems, and extreme ultraviolet lithography optical systems. Optical surface processing is one of the representative ultra-precision machining processes. Optical aspherical surfaces, due to their greater surface freedom, can specifically provide or correct different on-axis or off-axis aberrations, while simultaneously meeting the high-performance, lightweight, and miniaturized requirements of modern optical systems. They have gradually become a hot topic in modern optical engineering, and high-precision, mass production of aspherical lenses and their arrays has become an urgent manufacturing challenge for the aerospace and military defense fields.

[0051] Current processing techniques for optical surface molds do not consider the impact of grinding wheel wear on the processing of optical surface molds. Therefore, when performing error compensation on optical surface molds, the compensation results still contain errors. Hence, this application proposes a mold grinding error compensation method based on grinding wheel wear.

[0052] A method for compensating for mold grinding errors based on grinding wheel wear is applied to an error compensation system. The error compensation system is communicatively connected to the optical surface mold to be processed and the grinding wheel. The grinding wheel is used to perform grinding processing on the optical surface mold to be processed.

[0053] Grinding wheels are used in the grinding process of optical surface molds to perform grinding. The optical surface mold to be processed is the uncompensated optical surface mold after grinding by the grinding wheel. The error compensation system is a data processing system that acquires data information from the grinding wheel to determine the error compensation of the optical surface mold.

[0054] This application uses a 40mm diameter optical aspherical mold made of tungsten carbide as the optical surface mold to be processed. Other metal materials can also be used. However, because tungsten carbide aspherical molds are made of high-hardness materials, traditional ultra-precision cutting processes are difficult to use. Therefore, if... Figure 2 As shown, this application proposes a slow-tool servo single-point helical axis grinding process based on traditional ultra-precision turning. Diamond tools are replaced with diamond grinding wheels, and ultra-precision slow-tool servo single-point helical axis grinding is performed through the linkage of the C-axis, B-axis, X-axis, and Z-axis. This achieves high-precision machining of tungsten carbide optical aspherical molds. The optical surface mold to be processed after grinding is measured using a ZYGO white light interferometer (NexView NX2). Figure 3 The figure shown is a three-dimensional schematic diagram of the optical surface mold to be processed after grinding.

[0055] The aforementioned method for compensating for die grinding errors based on grinding wheel wear, such as... Figure 1 As shown, it includes the following steps:

[0056] S100. After each grinding process of the optical surface mold to be processed by the grinding wheel, the wear image of the grinding wheel to be processed is obtained.

[0057] Because grinding wheels wear to varying degrees depending on the number of grinding cycles, the more cycles, the greater the wear. Therefore, after each grinding cycle, error compensation must be performed on the optical surface mold to be processed. To consider the impact of grinding wheel wear on the processing of the optical surface mold, the compensation parameters must be determined based on the processing state of the grinding wheel. This involves obtaining the wear image of the grinding wheel after grinding, which is the unprocessed original image of the grinding wheel after grinding.

[0058] S100 also includes the following:

[0059] S110. If there is a shadow area at the edge of the wear image to be processed, the shadow area is blurred and eliminated, and step S200 is executed.

[0060] like Figure 4 The image shown is a wear image of a grinding wheel to be processed. Figure 4 The right edge of the grinding wheel in the left image has a shadow area. In order to obtain a more accurate edge profile of the grinding wheel, it is necessary to perform blur removal processing on the original surface to eliminate the shadow part in the image and reduce data processing errors. Existing image processing methods can be used for blur removal processing.

[0061] S200: Perform edge detection processing on the wear image to be processed to obtain the edge contour information of the grinding wheel;

[0062] After obtaining the wear image to be processed, which does not contain shadow areas, edge detection and extraction processing is performed to obtain the edge contour of the grinding wheel, such as... Figure 4 The right image shows the extracted edge profile of the grinding wheel.

[0063] The edge detection processing method in step S200 adopts the Canny edge detection algorithm to extract edge features after the grinding wheel wears. It mainly includes: smoothing the image with a Gaussian filter, calculating the magnitude and direction of the gradient using the finite difference of the first-order partial derivative, suppressing the gradient magnitude with non-maximum, and using a double threshold algorithm to detect and connect edges.

[0064] S300. Based on the edge contour information, determine the first edge feature point, the second edge feature point, and the third edge feature point; the first edge feature point and the second edge feature point are the left and right endpoints of the cross-sectional curve of the wear surface of the grinding wheel, respectively, and the third edge feature point is the endpoint that is on the same edge of the grinding wheel as the first edge feature point.

[0065] After obtaining the edge profile of the grinding wheel, to determine the compensation parameters of the optical surface mold to be processed, it is necessary to obtain information such as the area and volume of the wear surface of the grinding wheel. Since the grinding wheel is an axisymmetric regular object, its wear surface should be a uniformly worn surface. Therefore, it is only necessary to determine the two-dimensional edge profile of the grinding wheel.

[0066] like Figure 5 As shown, A is the first edge feature point, C is the second edge feature point, B is the third edge feature point, E is the initial grinding point of the grinding wheel, and the surface formed by the AC curve surrounding the central axis of the grinding wheel is the wear surface of the grinding wheel.

[0067] S400. Determine the vertical wear height H of the grinding wheel based on the first edge feature point, the second edge feature point, and the third edge feature point.

[0068] The vertical wear height H of the grinding wheel is determined by the following method:

[0069] S410. Draw the edge profile of the grinding wheel based on the edge profile information;

[0070] S420. Place the edge contour of the grinding wheel in a preset second coordinate system. The coordinates of the first edge feature point in the preset second coordinate system are (x...). A ,y A The coordinates of the second edge feature point in the preset second coordinate system are (x, y). C ,y C The coordinates of the third edge feature point in the preset second coordinate system are (x, y). B ,y B ); where the unit length of the preset second coordinate system is the same as that of the preset first coordinate system;

[0071] S430. Determine the slope k of the straight line between the first edge feature point and the third edge feature point. B -y A ) / (x B -x A );

[0072] S440, Determine the vertical wear height H = (k*x) C +y A -k*x A -y C ) / (1+k 2 ) 1 / 2 .

[0073] When determining the vertical height H of wear, first determine the slope of the straight line formed by the first edge feature point and the third edge feature point, and then obtain the vertical height H of wear by using this slope and the first edge feature point and the second edge feature point.

[0074] After extracting the contour features of the grinding wheel using the Canny edge detection algorithm, the wear area of ​​the grinding wheel is obtained. The wear feature area point cloud is extracted, the abrupt change slope of adjacent point clouds is calculated, and the contour feature points are obtained by solving based on the abrupt change slope threshold. Then, the single-point inclined axis grinding wear feature points of the cylindrical grinding wheel are obtained.

[0075] like Figure 5 As shown, the vertical wear height H can also be obtained by the slope between points C and D and points A and C.

[0076] S500. Determine the wear volume V of the grinding wheel based on the vertical wear height H.

[0077] The wear volume V of the grinding wheel is determined by the following method:

[0078] S510. Based on the increasing numerical values, obtain the abscissa of each coordinate point within the edge contour of the grinding wheel in the preset second coordinate system, and obtain the abscissa set of the grinding wheel X = (x1, x2, ..., x...). j ,...,x m ); where j = 1, 2, ..., m; m is the number of coordinate points of the grinding wheel within the edge contour of the preset second coordinate system; x j Let be the x-coordinate of the j-th coordinate point within the edge contour of the grinding wheel in the preset second coordinate system;

[0079] S520. Determine the wear volume of the grinding wheel.

[0080] First, sort all coordinate points of the grinding wheel in the second coordinate system according to the abscissa from smallest to largest. Then, integrate the grinding wheel in the second coordinate system to obtain the wear volume of the grinding wheel. The wear volume of the grinding wheel is used to determine the wear state of the grinding wheel. Then, according to the different wear states of the grinding wheel, corresponding error compensation is performed on the optical surface mold to be processed.

[0081] S600. If V > V0, then obtain the abscissa of the surface point cloud of the optical surface mold to be processed in the preset first coordinate system, and obtain the abscissa set of the mold point cloud U = (U1, U2, ..., U...). i ,...,U n ); where i = 1, 2, ..., n; n is the number of point clouds on the surface of the optical surface mold to be processed; U i V0 represents the abscissa of the i-th surface point cloud of the optical surface mold to be processed in the preset first coordinate system; V0 is the preset first wear volume threshold.

[0082] The S600 also includes the following:

[0083] S610. If V≤V0, a ​​warning signal is issued and the die grinding error compensation method based on grinding wheel wear is exited.

[0084] like Figure 6 The diagram shows the changes in the vertical wear height and wear volume of the grinding wheel as a function of the grinding cycle. Figure 6 It is known that the wear length of the grinding wheel increases with the increase of the wear cycle (the product of the number of wear cycles and the wear time). Therefore, after obtaining the wear volume V of the grinding wheel, it is compared with the first wear volume threshold. If it is greater than the first wear volume threshold, it means that the current wear state of the grinding wheel is normal wear, and the following data processing steps are continued. Conversely, if it is less than or equal to the first wear volume threshold, it means that the wear degree of the grinding wheel is too large and has exceeded the normal wear degree, which is an aggravated wear state. At this time, there is no need to perform the following steps. An alarm is directly triggered to remind the staff to replace the grinding wheel and re-grind the optical curved surface mold to be processed.

[0085] The first wear volume threshold is determined through prior experiments. Before error compensation is performed on the optical surface mold to be processed, grinding experiments are conducted on each type of grinding wheel. The average value of the experimental results is used to determine the grinding critical value of each type of grinding wheel. This grinding critical value is the first wear volume threshold.

[0086] S700, according to U i The grinding wheel's number of grinding passes (T) and radius (R) are used to determine the compensation correction parameter F for the i-th surface point cloud of the optical surface mold to be processed.i ;

[0087] Wherein, the compensation correction parameter F i It is determined by the following method:

[0088] S710. Determine the wear slope of the grinding wheel W = d * T + e; where d < 1, e < 1, and d and e are preset wear coefficients;

[0089] S720. Determine the compensation correction parameter F i =W / R*|U i |

[0090] After determining the wear state of the grinding wheel, if the grinding wheel is in a normal wear state, the wear slope of the grinding wheel is determined by the number of grinding cycles. The wear slope is linearly proportional to the number of grinding cycles. The more grinding cycles, the greater the wear of the grinding wheel, and the greater its wear slope, which indicates a greater degree of compensation for the optical curved surface mold to be processed.

[0091] Furthermore, when determining the wear slope, the wear slope can be determined more accurately based on different wear states of the grinding wheel. Therefore, another embodiment of step S710 is proposed:

[0092] Replace step S710 with:

[0093] S711. If V0 < V ≤ V1, then determine the wear slope W = d1 * T + e1; if V > V1, then determine the wear slope W = d2 * T + e2; where V1 is the preset second wear volume threshold, d1 < d2, e1 > e2, and d1, d2, e1, and e2 are preset wear coefficients.

[0094] The normal wear state of grinding wheels is divided into two states: initial wear and intermediate wear. A second wear volume threshold is set, and the wear volume of the grinding wheel is compared with the first and second wear volume thresholds. If the wear volume of the grinding wheel is between the first and second wear volume thresholds, it indicates that the grinding wheel is in the intermediate wear state; otherwise, it indicates that the grinding wheel is in the initial wear state. The wear coefficients used to determine the wear slope for the two wear states are different. Since the wear degree in the initial wear state is less than that in the intermediate wear state, its wear coefficient e2 is less than e1. Since d1 and d2 are both greater than zero and less than 1, d1 is less than d2 as the product coefficient of the number of grinding cycles of the grinding wheel. By judging the different wear degrees of the grinding wheel, the grinding wheel can be replaced and the optical surface mold to be processed can be compensated for errors. This improves the accuracy of the compensation for the optical surface mold to be processed and avoids the loss of the optical surface mold to be processed due to excessive wear of the grinding wheel.

[0095] S800, according to F i U i The base circle radius R of the optical surface mold to be processed base The compensation correction value Z of the i-th surface point cloud of the optical surface mold to be processed is obtained. i ;

[0096] Among them, the compensation correction value Z i It is determined by the following formula:

[0097] Z i =(U i ) 2 / (R base +((R base ) 2 -(1+g)*(U i ) 2 ) 1 / 2 )+∑ b a＝2 L a (U i ) a -ΔZ-F i ;

[0098] Where: g < 1, g is the preset compensation coefficient; L a The compensation correction coefficient is ΔZ = Z. (i-1) -Z0, where Z0 is the preset compensation correction threshold and b is the preset power threshold.

[0099] like Figure 7 As shown, due to the large diameter of the optical surface mold to be processed, the grinding wheel is prone to wear during a single compensation process. If wheel wear is not considered, the edge area of ​​the optical surface mold to be processed is not easily ground, resulting in the upward warping of the ground surface. Therefore, considering that the grinding wheel is prone to wear during the compensation process, when the grinding wheel wears, it will generate a pose error relative to the optical surface mold to be processed. The grinding wheel pose can be adjusted according to the amount of wear, forming an optical aspherical single-point oblique axis grinding error compensation algorithm that considers pose error. Therefore, after obtaining the compensation correction parameters of the point cloud of each surface of the optical surface mold to be processed, the compensation correction value corresponding to each surface point cloud is determined according to the base circle radius of the optical surface mold to be processed and the abscissa of each surface point cloud of the optical surface mold to be processed. The compensation correction value is the compensation parameter of each surface point cloud of the optical surface mold to be processed. When the grinding wheel is grinding for the first time, ΔZ is zero.

[0100] The compensation coefficient, compensation correction coefficient, and compensation correction threshold were all determined through prior experiments.

[0101] S900, according to Z1, Z2, ..., Z i ,...,Z n The mold correction machine controls the correction of the optical surface mold to be processed.

[0102] like Figure 8 The figure shows a schematic diagram of the contour error of the optical surface mold to be processed after grinding compensation under different scenarios. Figure 8 There are three curves in total. The top curve is the profile error curve before grinding compensation, the middle curve is the profile error curve after grinding compensation without considering the grinding wheel wear factor, and the bottom curve is the profile error curve after grinding compensation considering the grinding wheel wear factor. Therefore, from Figure 8 It is evident that traditional error compensation methods do not consider grinding wheel wear during the compensation process, resulting in a less significant compensation effect compared to traditional methods. However, improved compensation methods that take grinding wheel wear into account can enhance both compensation efficiency and accuracy.

[0103] This invention compensates for errors in optical surface molds based on the wear factor of grinding wheels. It obtains the edge contour of the grinding wheel by performing edge detection on the measured wear image after in-situ measurement, and uses a slope mutation algorithm to obtain the feature points of the edge contour. The wear volume of the wear area is then calculated. Based on the number of grinding passes, the radius of the grinding wheel, and the base circle radius of the optical surface mold, a compensation correction value is obtained for each point cloud of the optical surface mold. Error compensation is then performed on the corresponding point cloud using each compensation correction value. This invention adds the wear factor of grinding wheels to the error compensation process for optical surface molds, enriching the traditional compensation evaluation indicators for optical surface molds. Compared with traditional compensation methods, it improves the compensation accuracy and facilitates high-precision machining of optical surface molds.

[0104] Embodiments of the present invention also provide a non-transitory computer-readable storage medium that can be disposed in an electronic device to store at least one instruction or at least one program related to implementing a method in the method embodiments, wherein the at least one instruction or the at least one program is loaded and executed by the processor to implement the method provided in the above embodiments.

[0105] Embodiments of the present invention also provide an electronic device, including a processor and the aforementioned non-transitory computer-readable storage medium.

[0106] While specific embodiments of the invention have been described in detail by way of example, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art should also understand that various modifications can be made to the embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A method for compensating for die grinding errors based on grinding wheel wear, characterized in that, An error compensation system is applied, wherein the error compensation system is communicatively connected to an optical surface mold to be processed and a grinding wheel, the grinding wheel being used to perform grinding processing on the optical surface mold to be processed, and the method includes the following steps: S100. Whenever the grinding wheel performs grinding processing on the optical surface mold to be processed, the wear image of the grinding wheel to be processed is obtained. S200: Perform edge detection processing on the wear image to be processed to obtain the edge contour information of the grinding wheel; S300. Based on the edge contour information, determine the first edge feature point, the second edge feature point, and the third edge feature point; the first edge feature point and the second edge feature point are the left and right endpoints of the cross-sectional curve of the wear surface of the grinding wheel, respectively, and the third edge feature point is the endpoint that is on the same edge as the first edge feature point on the grinding wheel. S400. Determine the wear vertical height H of the grinding wheel based on the first edge feature point, the second edge feature point, and the third edge feature point; S500. Determine the wear volume V of the grinding wheel based on the wear vertical height H. S600. If V > V0, then obtain the abscissa of the surface point cloud of the optical surface mold to be processed in the preset first coordinate system, and obtain the mold point cloud abscissa set U = (U1, U2, ..., U...). i ,...,U n ); where i = 1, 2, ..., n; n is the number of point clouds on the surface of the optical surface mold to be processed; U i V0 represents the abscissa of the i-th surface point cloud of the optical surface mold to be processed in the preset first coordinate system; V0 is the preset first wear volume threshold. S700, according to U i The number of grinding passes T of the grinding wheel and the radius R of the grinding wheel are used to determine the compensation correction parameter F for the i-th surface point cloud of the optical surface mold to be processed. i ; S800, according to F i U i The base circle radius R of the optical surface mold to be processed base The compensation correction value Z of the i-th surface point cloud of the optical surface mold to be processed is obtained. i ; S900, according to Z1, Z2, ..., Z i ,...,Z n The mold correction machine is controlled to correct the optical surface mold to be processed.

2. The method for compensating for die grinding errors based on grinding wheel wear according to claim 1, characterized in that, The vertical wear height H of the grinding wheel is determined by the following method: S410. Draw the edge contour of the grinding wheel based on the edge contour information; S420. Place the edge contour of the grinding wheel in a preset second coordinate system, where the coordinates of the first edge feature point in the preset second coordinate system are (x...). A ,y A The coordinates of the second edge feature point in the preset second coordinate system are (x, y, y). C ,y C The coordinates of the third edge feature point in the preset second coordinate system are (x, y, y). B ,y B ); where the unit length of the preset second coordinate system is the same as that of the preset first coordinate system; S430. Determine the slope k = (y_i - y_i) of the straight line between the first edge feature point and the third edge feature point. B -y A ) / (x B -x A ); S440, Determine the vertical wear height H = (k*x) C +y A -k*x A -y C ) / (1+k 2 ) 1 / 2 .

3. The method for compensating for mold grinding errors based on grinding wheel wear according to claim 2, characterized in that, The wear volume V of the grinding wheel is determined by the following method: S510. Based on the increasing numerical values, obtain the abscissa of each coordinate point within the edge contour of the grinding wheel in the preset second coordinate system, and obtain the abscissa set X = (x1, x2, ..., x...). j ,...,x m ); where j = 1, 2, ..., m; m is the number of coordinate points of the grinding wheel within the edge contour in the preset second coordinate system; x j Let be the x-coordinate of the j-th coordinate point within the edge contour of the grinding wheel in the preset second coordinate system; S520. Determine the wear volume of the grinding wheel.

4. The method for compensating for die grinding errors based on grinding wheel wear according to claim 1, characterized in that, The S600 also includes: S610. If V≤V0, a ​​warning signal is issued and the method for compensating for mold grinding errors based on grinding wheel wear is exited.

5. The method for compensating for die grinding errors based on grinding wheel wear according to claim 1, characterized in that, The compensation correction parameter F i It is determined by the following method: S710. Determine the wear slope of the grinding wheel as W = d * T + e; where d < 1, e < 1, and d and e are preset wear coefficients. S720. Determine the compensation correction parameter F i =W / R*|U i | 6. The method for compensating for die grinding errors based on grinding wheel wear according to claim 5, characterized in that, The compensation correction value Z i It is determined by the following formula: Z i =(U i ) 2 / (R base +((R base ) 2 -(1+g)*(U i ) 2 ) 1 / 2 )+∑ b a＝2 L a (U i ) a -ΔZ-F i ; Where: g < 1, g is the preset compensation coefficient; L a The compensation correction coefficient is ΔZ = Z. (i-1) -Z0, where Z0 is the preset compensation correction threshold; b is the preset power threshold.

7. The method for compensating for die grinding errors based on grinding wheel wear according to claim 5, characterized in that, Replace S710 with: S711. If V0 < V ≤ V1, then determine the wear slope W = d1 * T + e1; if V > V1, then determine the wear slope W = d2 * T + e2. Where V1 is the preset second wear volume threshold, d1 < d2, e1 > e2, and d1, d2, e1, and e2 are preset wear coefficients.

8. The method for compensating for die grinding errors based on grinding wheel wear according to claim 1, characterized in that, The S100 further includes: S110. If there is a shadow area at the edge of the wear image to be processed, the shadow area is blurred and eliminated, and step S200 is executed.

9. A non-transitory computer-readable storage medium, wherein the storage medium stores at least one instruction or at least one program segment, characterized in that, The at least one instruction or the at least one program segment is loaded and executed by the processor to implement the die grinding error compensation method based on grinding wheel wear as described in any one of claims 1-8.

10. An electronic device, characterized in that, Includes a processor and the non-transitory computer-readable storage medium as described in claim 9.

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