Tool path planning method for CNC vertical machining centers

Abstract

The present invention discloses a tool path planning method for a CNC vertical machining center, and relates to the technical field of industrial equipment automation. The tool path planning method for a CNC vertical machining center comprises: obtaining first contour information of a target workpiece and second contour information of an original workpiece, wherein the target workpiece is used to characterize an ideal workpiece expected to be obtained after cutting, and the original workpiece is used to characterize an actual workpiece subjected to cutting; using the second contour information, determining the local contour complexity corresponding to each workpiece position point in the original workpiece; based on the first contour information and each local contour complexity, correcting the initial cutting parameters of each workpiece position point in the original workpiece, and obtaining the actual cutting parameters of each workpiece position point in the original workpiece; and planning the tool path of each workpiece position point in the original workpiece based on the actual cutting parameters of each workpiece position point in the original workpiece.

Description

Technical Field

[0001] The invention relates to the technical field of industrial equipment automation, and in particular to a tool path planning method for a numerically controlled vertical machining machine tool. Background Art

[0002] With the rapid development of modern manufacturing industry, CNC vertical machining centers are increasingly used in the field of mechanical processing. Tool path planning, as a key link in the CNC machining process, directly affects the machining quality and efficiency. In CNC vertical machining centers, the selection and optimization of tool path planning methods are of great significance for improving machining accuracy, reducing machining costs, and improving production efficiency.

[0003] In the existing methods, the original workpiece is usually cut directly according to the contour of the target workpiece using a uniform cutting method to obtain a finished workpiece.

[0004] However, since the contour of the original workpiece will change during different cutting processes, using a uniform cutting method will result in an uneven surface of the final finished workpiece and poor cutting quality. Summary of the invention

[0005] The embodiment of the present invention provides a tool path planning method for a CNC vertical machining center, which can improve cutting quality.

[0006] A first aspect of an embodiment of the present invention provides a tool path planning method for a CNC vertical machining center, comprising:

[0007] Acquire first contour information of a target workpiece and second contour information of an original workpiece, wherein the target workpiece is used to characterize an ideal workpiece expected to be obtained after cutting, and the original workpiece is used to characterize an actual workpiece to be cut;

[0008] Determine the local contour complexity corresponding to each workpiece position point in the original workpiece by using the second contour information;

[0009] Based on the first contour information and the complexity of each local contour, the initial cutting parameters of each workpiece position point in the original workpiece are corrected to obtain the actual cutting parameters of each workpiece position point in the original workpiece;

[0010] Based on the actual cutting parameters of each workpiece position point in the original workpiece, the tool trajectory of each workpiece position point in the original workpiece is planned.

[0011] In the tool path planning method for a CNC vertical machining center provided by an embodiment of the present invention, the second contour information of the original workpiece is used to determine the local contour complexity corresponding to each workpiece position point in the original workpiece. Then, based on the first contour information and each local contour complexity, the initial cutting parameters of each workpiece position point in the original workpiece are corrected in real time to obtain the actual cutting parameters of each workpiece position point in the original workpiece. In this way, according to the different local contour complexities corresponding to the original workpiece in different cutting processes and at different workpiece position points, the embodiment of the present invention timely corrects the initial cutting parameters of each workpiece position point in the original workpiece in real time, thereby avoiding the problem of uneven surface of the final finished workpiece caused by a uniform cutting method, and improving the cutting quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 A schematic flow chart of a first tool path planning method for a CNC vertical machining center provided by an embodiment of the present invention;

[0014] Figure 2 A schematic diagram of first profile information and second profile information provided by an embodiment of the present invention;

[0015] Figure 3 A schematic flow chart of a second tool path planning method for a CNC vertical machining center provided by an embodiment of the present invention;

[0016] Figure 4 A schematic flow chart of a third tool path planning method for a CNC vertical machining center provided by an embodiment of the present invention;

[0017] Figure 5 A schematic flow chart of a fourth tool path planning method for a CNC vertical machining center provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the tool path planning method for a CNC vertical machining center proposed by the present invention, its specific implementation method, structure, features and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0019] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0020] It should be noted that the acquisition, storage, use, and processing of data in the technical solution of the present invention are in compliance with the relevant provisions of laws and regulations.

[0021] It should be noted that in the embodiments of the present invention, certain software, components, models and other existing solutions in the industry may be mentioned, which should be regarded as exemplary. Their purpose is only to illustrate the feasibility of implementing the technical solution of the present invention, but it does not mean that the applicant has or will necessarily use the solution.

[0022] In the existing methods, the original workpiece is usually cut directly according to the contour of the target workpiece using a uniform cutting method to obtain a finished workpiece. However, since the contour of the original workpiece will change during different cutting processes, the uniform cutting method will result in an uneven surface of the final finished workpiece and poor cutting quality.

[0023] The object of the present invention is to provide a tool path planning method for a CNC vertical machining center. In the tool path planning method for a CNC vertical machining center provided by an embodiment of the present invention, the local contour complexity corresponding to each workpiece position point in the original workpiece is determined by using the second contour information of the original workpiece. Then, based on the first contour information and each local contour complexity, the initial cutting parameters of each workpiece position point in the original workpiece are corrected in real time to obtain the actual cutting parameters of each workpiece position point in the original workpiece. In this way, the embodiment of the present invention timely corrects the initial cutting parameters of each workpiece position point in the original workpiece in real time according to the different local contour complexities corresponding to the original workpiece in different cutting processes and at different workpiece position points, thereby avoiding the problem of uneven surface of the final finished workpiece caused by a uniform cutting method, and improving the cutting quality.

[0024] The following describes a specific embodiment of a tool path planning method for a CNC vertical machining center provided by an embodiment of the present invention.

[0025] Figure 1A flow chart of a tool path planning method for a CNC vertical machining center is provided. The tool path planning method for a CNC vertical machining center can be applied to a server. The tool path planning method for a CNC vertical machining center can include the following S101 to S104.

[0026] S101, obtaining first contour information of a target workpiece and second contour information of an original workpiece, wherein the target workpiece is used to characterize an ideal workpiece expected to be obtained after cutting, and the original workpiece is used to characterize an actual workpiece to be cut.

[0027] In this embodiment, the first contour information is used to characterize contour information of an ideal workpiece expected to be obtained after cutting, and the second contour information is used to characterize contour information of an actual workpiece undergoing cutting.

[0028] As an example, a 3D model of a target workpiece is imported into Computer Aided Manufacturing (CAM) software, and at the same time, the current workpiece shape of an original workpiece being cut is imported, thereby obtaining first contour information of the target workpiece and second contour information of the original workpiece.

[0029] like Figure 2 As shown, a schematic diagram of the first contour information and the second contour information is provided. Among them, the straight line S1 is the second contour information of the initialized original workpiece, that is, the second contour information of the original workpiece before any cutting operation is performed. At this time, the initialized original workpiece is cylindrical, and the distance between the straight line S1 and the y-axis is the radius length of the initialized original workpiece. The curve S2 is the first contour information of the target workpiece, and at this time, the distance between each point on the curve S2 and the y-axis is the radial distance between the point on the outer contour of the target workpiece and the center of the target workpiece.

[0030] S102: Determine the local contour complexity corresponding to each workpiece position point in the original workpiece by using the second contour information.

[0031] In this embodiment, the local contour complexity is used to characterize the contour complexity of the local area where the workpiece position point of the original workpiece is located. The higher the local contour complexity, the greater the processing difficulty of the workpiece position point, and the more sophisticated cutting control is required.

[0032] As an example, the server uses a data analysis tool to perform a detailed analysis of the current second contour information of the original workpiece. Identify the different local areas corresponding to each preset workpiece position point in the original workpiece, such as planes, curved surfaces, corners, etc.; and the geometric features of the local areas corresponding to each workpiece position point, such as curvature, inclination, etc. Then, according to the shape change degree and corresponding geometric features of each identified local area, assign a corresponding local contour complexity value to each workpiece position point.

[0033] S103, based on the first contour information and the complexity of each local contour, correct the initial cutting parameters of each workpiece position point in the original workpiece to obtain the actual cutting parameters of each workpiece position point in the original workpiece.

[0034] In this embodiment, the cutting parameters are used to characterize the corresponding parameters when performing cutting processing. For example, the cutting parameters may include cutting speed, feed rate, cutting depth, etc.

[0035] Among them, the cutting speed refers to the instantaneous speed of the selected point on the cutting edge of the tool relative to the surface to be machined of the original workpiece in the main motion direction; the feed rate refers to the relative displacement between the tool and the workpiece along the feed motion direction for each rotation of the main motion or each cutting stroke; the cutting depth refers to the vertical distance between the surface to be machined of the original workpiece and the machined surface of the target workpiece.

[0036] The initial cutting parameters are used to characterize the initial values ​​of the cutting parameters set based on experience or standards, and the actual cutting parameters are used to characterize the actual values ​​of the cutting parameters in the next cutting process obtained after the initial values ​​of the cutting parameters are corrected.

[0037] As an example, the server combines the first contour information and the local contour complexity of each workpiece position point to evaluate the cutting conditions required to achieve the ideal shape, thereby determining the correction weights corresponding to the initial cutting parameters of each workpiece position point. Then, the initial cutting parameters of each workpiece position point in the original workpiece are corrected according to each correction weight to obtain the actual cutting parameters of each workpiece position point in the original workpiece.

[0038] Specifically, for areas with high local contour complexity, it is necessary to reduce the cutting speed, reduce the feed rate or increase the fineness of the cutting depth adjustment to avoid vibration, tool wear and degradation of the workpiece surface quality; for areas with low local contour complexity, the cutting speed and feed rate can be increased accordingly to improve machining efficiency.

[0039] S104, planning a tool trajectory for each workpiece position point in the original workpiece based on actual cutting parameters of each workpiece position point in the original workpiece.

[0040] In this embodiment, the server generates a tool path using CAM software according to the corrected actual cutting parameters, wherein the tool path should ensure that the tool can efficiently and accurately remove the material according to the predetermined cutting parameters and trajectory to achieve the shape and size requirements of the target workpiece.

[0041] In the tool path planning method for a CNC vertical machining center provided in this embodiment, the second contour information of the original workpiece is used to determine the local contour complexity corresponding to each workpiece position point in the original workpiece. Then, based on the first contour information and each local contour complexity, the initial cutting parameters of each workpiece position point in the original workpiece are corrected in real time to obtain the actual cutting parameters of each workpiece position point in the original workpiece. In this way, the embodiment of the present invention timely corrects the initial cutting parameters of each workpiece position point in the original workpiece in real time according to the different local contour complexities corresponding to the original workpiece in different cutting processes and at different workpiece position points, thereby avoiding the problem of uneven surface of the final finished workpiece caused by a uniform cutting method, and improving the cutting quality.

[0042] As an optional embodiment, Figure 3 As shown, S102 may specifically include the following S301 to S303:

[0043] S301, based on the second contour information, taking the target workpiece position point in the original workpiece as the center, extending N workpiece position points to the left and right sides respectively, to construct a local area of ​​the target workpiece position point, where N is a positive integer;

[0044] S302, obtaining a first slope of a first curve formed by N workpiece position points on the left side of a target workpiece position point in a local area, and obtaining a second slope of a second curve formed by N workpiece position points on the right side of the target workpiece position point in the local area;

[0045] S303: Determine the local contour complexity corresponding to the target workpiece position point by using the first slope and the second slope.

[0046] In this embodiment, the target workpiece position point is any one of a plurality of workpiece position points preset for the original workpiece.

[0047] The first slope is used to characterize the slope of a first curve formed by each workpiece position point located on the left side of the target workpiece position point in the local area of ​​the target workpiece position point; the second slope is used to characterize the slope of a second curve formed by each workpiece position point located on the right side of the target workpiece position point in the local area of ​​the target workpiece position point.

[0048] As an example, the server obtains the target workpiece position point in the original workpiece according to the second contour information, and simultaneously extends and obtains the N workpiece position points adjacent to the left side of the target workpiece position point and the N workpiece position points adjacent to the right side of the target workpiece position point. Then, the extended workpiece position points are combined with the original target workpiece position points to construct a local area containing the target workpiece position point.

[0049] Then, according to the constructed local area, determine the first curve formed by the N workpiece position points on the left side of the target workpiece position point and the second curve formed by the N workpiece position points on the right side of the target workpiece position point. And use the slope calculation formula to calculate the slopes of the first curve and the second curve respectively. Among them, since the workpiece contour is a curve rather than a straight line, the slope here is actually the average of the tangent slopes of each workpiece position point on the curve.

[0050] Finally, the calculated first slope and second slope are used as the basis for evaluating the complexity of the local contour. The larger the absolute value of the slope, the greater the curvature of the curve near the point; the positive or negative value of the slope reflects the curvature direction of the curve. According to the values ​​and change trends of the first slope and the second slope, the local contour complexity corresponding to the position point of the target workpiece is evaluated. For example, if the absolute values ​​of the first slope and the second slope are both large and the change trends are opposite, it may indicate that the contour near the point has large curvature and changes; if the slope value is small and the change trend is consistent, it may indicate that the contour near the point is relatively smooth and stable.

[0051] Through this embodiment, a local area of ​​the target workpiece position point is constructed, and then the first slope and the second slope in the local area are calculated, and finally the local contour complexity is evaluated according to the first slope and the second slope. In this way, an accurate evaluation of the local contour complexity corresponding to the workpiece position point is achieved, which helps to correct the initial cutting parameters of the workpiece position point later and improve the cutting quality.

[0052] As an optional embodiment, S303 may specifically include:

[0053] Square the difference between the first slope and the second slope to obtain a first calculated value;

[0054] Square the sum of the absolute value of the first slope and the absolute value of the second slope to obtain a second calculated value;

[0055] The accumulated value of the first calculated value and the second calculated value is squared to obtain the local contour complexity corresponding to the target workpiece position point.

[0056] In this embodiment, the local contour complexity corresponding to the target workpiece position point can be specifically determined by the following formula 1:

[0057] Formula 1

[0058] In the formula, It is used to characterize the local contour complexity of the target workpiece position point j during the i-th cutting process. The first slope used to characterize the target workpiece position point j, The second slope used to characterize the target workpiece position point j.

[0059] Among them, the first slope of the target workpiece position point j is The second slope with the target workpiece position point j The greater the difference, the greater the local contour complexity of the target workpiece position j during the i-th cutting process. The bigger.

[0060] Among them, the local contour complexity of the target workpiece position point j during the i-th cutting process is The larger it is, the higher the contour complexity of the local area where the target workpiece position point j is located during the i-th cutting process, that is, the greater the processing difficulty of the target workpiece position point j, the smaller the corresponding cutting depth should be.

[0061] Through this embodiment, the local contour complexity of the local area where the target workpiece position point is located can be accurately calculated according to the first slope and the second slope of the target workpiece position point. In this way, an accurate evaluation of the local contour complexity corresponding to the workpiece position point is achieved, which helps to subsequently correct the initial cutting parameters of the workpiece position point and improve the cutting quality.

[0062] As an optional embodiment, the cutting parameters include cutting depth;

[0063] S103 may specifically include:

[0064] Determine a first depth difference between a target workpiece position point in the original workpiece and a corresponding workpiece position point in the target workpiece using the first contour information;

[0065] The first depth difference is divided by the local contour complexity corresponding to the target workpiece position point and then normalized to obtain a first correction weight corresponding to the cutting depth;

[0066] The initial cutting depth of the target workpiece position point in the original workpiece is multiplied by the first correction weight to obtain the target actual cutting depth of the target workpiece position point in the original workpiece.

[0067] In this embodiment, the target actual cutting depth of the target workpiece position point in the original workpiece can be specifically determined by the following formula 2:

[0068] Formula 2

[0069] In the formula, Used to characterize the target actual cutting depth of the target workpiece position point j in the i-th cutting process. It is used to characterize the initial cutting depth of the target workpiece position point j, wherein the initial cutting depth may be a preset value. It is used to characterize the first depth difference between the target workpiece position point j in the original workpiece and the workpiece position point in the corresponding target workpiece during the i-th cutting process, that is, the vertical distance between the target workpiece position point j in the original workpiece and the workpiece position point in the corresponding target workpiece. It is used to characterize the local contour complexity of the target workpiece position point j during the i-th cutting process. When the value is 0, it is replaced by 0.1 to prevent the denominator from being 0. Used to characterize normalized calculations.

[0070] Among them, the local contour complexity of the target workpiece position point j during the i-th cutting process is The larger the value is, the smaller the cutting depth of the target workpiece position point j in the i-th cutting process should be; the first depth difference between the target workpiece position point j in the original workpiece and the workpiece position point in the corresponding target workpiece in the i-th cutting process is The larger it is, the greater the cutting depth of the target workpiece position point j in the i-th cutting process should be.

[0071] Through this embodiment, based on the local contour complexity of each workpiece position point in the original workpiece, the initial cutting depth of each workpiece position point in the original workpiece is corrected, so as to obtain the actual cutting depth of each workpiece position point in the original workpiece. In this way, by correcting the initial cutting depth of each workpiece position point in the original workpiece, the cutting quality can be improved.

[0072] As an optional embodiment, the cutting parameters include cutting speed;

[0073] like Figure 4 As shown, S103 may specifically include the following S401 to S403:

[0074] S401, based on the local contour complexity corresponding to the target workpiece position point, correct the initial cutting speed corresponding to the target workpiece position point to obtain a theoretical cutting speed;

[0075] S402, constructing a speed optimization function corresponding to the target workpiece position point based on the first contour information and the theoretical cutting speed;

[0076] S403, using the speed optimization function, determining the target actual cutting speed corresponding to the target workpiece position point.

[0077] In this embodiment, the speed optimization function is used to characterize the corresponding relationship between the actual cutting speed and the corresponding cutting effect, so as to determine the actual cutting speed corresponding to the best cutting effect.

[0078] As an example, based on the local contour complexity corresponding to the target workpiece position point, the server corrects the initial cutting speed of the target workpiece position point through a target algorithm (such as linear interpolation, nonlinear mapping, etc.), thereby obtaining the theoretical cutting speed of the target workpiece position point. Specifically, the workpiece position point with high local contour complexity needs to reduce the cutting speed to reduce tool wear and ensure machining accuracy, while the workpiece position point with low local contour complexity can appropriately increase the cutting speed to improve machining efficiency.

[0079] Then, based on the first contour information of the target workpiece and the theoretical cutting speed of the target workpiece position point, a speed optimization function corresponding to the target workpiece position point is constructed. The goal of the speed optimization function is to find a balance point so that the processing efficiency can be improved and the tool life can be extended as much as possible while satisfying the processing quality, that is, the overall cutting effect is optimized. The speed optimization function can contain multiple variables, such as cutting speed, feed rate, etc., and is solved by a target method (such as linear programming, nonlinear optimization, etc.).

[0080] Finally, by solving the speed optimization function, the target actual cutting speed corresponding to the target workpiece position point is obtained.

[0081] Through this embodiment, a speed optimization function is constructed based on the first contour information of the target workpiece and the local contour complexity of the workpiece position point in the original workpiece. Therefore, the target actual cutting speed corresponding to the workpiece position point can be determined by using the speed optimization function. In this way, the cutting quality can be improved by correcting the initial cutting speed of each workpiece position point in the original workpiece.

[0082] As an optional embodiment, S401 may specifically include:

[0083] The local contour complexity corresponding to the position point of the target workpiece is normalized and calculated to obtain the normalized contour complexity;

[0084] Determining a second correction weight corresponding to the cutting speed by using the normalized contour complexity;

[0085] The initial cutting speed of the target workpiece position point in the original workpiece is multiplied by the second correction weight to obtain the theoretical cutting speed of the target workpiece position point in the original workpiece.

[0086] In this embodiment, the theoretical cutting speed of the target workpiece position point in the original workpiece can be specifically determined by the following formula 3:

[0087] Formula 3

[0088] In the formula, It is used to characterize the theoretical cutting speed of the target workpiece position j during the i-th cutting process. It is used to characterize the local contour complexity of the target workpiece position point j during the i-th cutting process. Used to characterize the initial cutting speed of the target workpiece position point j, Used to characterize normalized calculations.

[0089] Among them, the local contour complexity of the target workpiece position point j during the i-th cutting process is The larger it is, the smaller the cutting speed of the target workpiece position point j in the i-th cutting process should be.

[0090] Through this embodiment, based on the local contour complexity of the target workpiece position point in the original workpiece, the initial cutting depth of the target workpiece position point in the original workpiece is corrected, thereby obtaining the theoretical cutting depth of the target workpiece position point in the original workpiece. In this way, it is helpful to correct the initial cutting depth of the target workpiece position point in the original workpiece according to the theoretical cutting depth, obtain the target actual cutting speed corresponding to the target workpiece position point, and improve the cutting quality.

[0091] As an optional embodiment, S402 may specifically include:

[0092] Based on the first contour information, an absolute value of a difference in actual cutting speed between each two adjacent workpiece position points in a local area corresponding to the target workpiece position point in the original workpiece is obtained;

[0093] The absolute values ​​of the actual cutting speed differences are accumulated to obtain the target accumulated value;

[0094] The actual cutting speed of the target workpiece position point is taken as the independent variable, the absolute value of the difference between the actual cutting speed of the target workpiece position point and the theoretical cutting speed, and the product of the target accumulated value are taken as the dependent variables, and the speed optimization function corresponding to the target workpiece position point is constructed.

[0095] In this embodiment, the speed optimization function corresponding to the target workpiece position point is specifically shown in the following formula 4:

[0096] Formula 4

[0097] In the formula, F is used to characterize the speed optimization function corresponding to the target workpiece position point. It is used to characterize the actual cutting speed of the target workpiece position j during the i-th cutting process. It is used to characterize the theoretical cutting speed of the target workpiece position j during the i-th cutting process. It is used to characterize the actual cutting speed of the workpiece position point r in the local area corresponding to the target workpiece position point j during the i-th cutting process. It is used to characterize the actual cutting speed of the workpiece position point r+1 in the local area corresponding to the target workpiece position point j during the i-th cutting process. It is used to characterize the total number of workpiece position points in the local area corresponding to the target workpiece position point j. It is used to represent the target cumulative value obtained by adding the absolute values ​​of the actual cutting speed differences between each two adjacent workpiece position points in the local area corresponding to the target workpiece position point j.

[0098] Among them, during the continuous movement process, the cutting speed change between adjacent workpiece position points should be relatively uniform, that is, the cutting speed difference between adjacent workpiece position points should be as small as possible; at the same time, during the cutting process, the difference between the actual cutting speed and the theoretical cutting speed should be as small as possible.

[0099] Among them, the smaller the function value of the speed optimization function F corresponding to the target workpiece position point, the better the cutting effect of the target position point, that is, the better the corresponding actual cutting speed.

[0100] Through this embodiment, based on the first profile information and the theoretical cutting speed, a speed optimization function corresponding to the target workpiece position point is constructed. In this way, it is helpful to use the speed optimization function to determine the optimal target actual cutting speed of the target workpiece position point, thereby improving the cutting quality.

[0101] As an optional embodiment, S403 may specifically include:

[0102] Obtain the actual cutting speed value range corresponding to the target workpiece position point;

[0103] Within the range of actual cutting speed values, the actual cutting speed corresponding to the minimum function value of the speed optimization function is determined as the target actual cutting speed corresponding to the target workpiece position point.

[0104] In this embodiment, the server obtains the material properties of the target workpiece, such as hardness, toughness, thermal conductivity, etc.; and obtains the cutting tool properties, such as the material, type, hardness, edge shape, etc. of the cutting tool. Then, according to the material properties of the target workpiece and the cutting tool properties, the server consults the relevant cutting parameter manual or database to obtain the actual cutting speed value range corresponding to the target workpiece position point. For example, the actual cutting speed value range of the target workpiece position point j in the i-th cutting process can be ,in It is used to characterize the theoretical cutting speed of the target workpiece position point j during the i-th cutting process, and V is used to characterize the preset adjustable unit speed.

[0105] Then, taking the actual cutting speed value range corresponding to the target workpiece position point as the constraint condition, the minimum function value of the speed optimization function within the actual cutting speed value range is obtained, and the actual cutting speed corresponding to the minimum function value is determined as the target actual cutting speed.

[0106] Through this embodiment, within the range of actual cutting speed values ​​corresponding to the target workpiece position point, the actual cutting speed corresponding to the minimum function value of the speed optimization function is determined as the target actual cutting speed corresponding to the target workpiece position point. In this way, the speed optimization function can be used to accurately determine the optimal target actual cutting speed of the target workpiece position point, thereby improving the cutting quality.

[0107] As an optional embodiment, Figure 5 As shown, before S103, the tool path planning method for a CNC vertical machining center may further include the following S501 to S502:

[0108] S501, obtaining a maximum cutting depth of a tool and a second depth difference between corresponding workpiece position points of a target workpiece and an initialized original workpiece;

[0109] S502: using the maximum cutting depth and each second depth difference, respectively determine the initial cutting depth of each workpiece position point in the original workpiece.

[0110] In this embodiment, the initialized original workpiece is used to represent the workpiece raw material that has not been cut.

[0111] The second depth difference is used to represent the depth difference between the target workpiece and the corresponding workpiece position point in the initialized original workpiece.

[0112] As an example, the server first obtains the cutting tool characteristics, such as the material, type, hardness, edge shape, etc. of the tool, so as to determine the maximum cutting depth of the tool.

[0113] Then, corresponding workpiece position points in the target workpiece and the original workpiece are respectively acquired according to the first contour information of the target workpiece and the second contour information of the original workpiece, and a second depth difference between the corresponding workpiece position points in the target workpiece and the original workpiece is acquired.

[0114] Finally, an initial cutting depth is assigned to each workpiece position point in the original workpiece based on the maximum cutting depth and the respective second depth difference values. This initial cutting depth should be less than or equal to the maximum cutting depth and take into account the second depth difference value of the position point to ensure that the load capacity of the machine tool and the tool is not exceeded during the cutting process.

[0115] Through this embodiment, the initial cutting depth of each workpiece position point of the original workpiece is set according to the maximum cutting depth of the tool and the second depth difference between the target workpiece and each corresponding workpiece position point of the initialized original workpiece. In this way, it can be ensured that the carrying capacity of the machine tool and the tool will not be exceeded during the cutting process, thereby improving cutting safety.

[0116] As an optional embodiment, S502 may specifically include:

[0117] Obtaining a maximum second depth difference value among the second depth differences;

[0118] Divide the maximum value of the second depth difference by the maximum cutting depth to obtain the minimum number of cutting times for the original workpiece;

[0119] Each second depth difference is divided by the minimum number of cutting times to obtain an initial cutting depth for each workpiece position point in the original workpiece.

[0120] In this embodiment, the second maximum depth difference value is used to represent the maximum amount of material that needs to be cut at each workpiece position point of the original workpiece.

[0121] As an example, the server searches for the maximum second depth difference value among the second depth differences, and then divides the maximum second depth difference value by the maximum cutting depth of the tool, so that we can obtain the minimum number of cutting times required in theory.

[0122] Then, for each workpiece position point of the original workpiece, the corresponding second depth difference is divided by the minimum number of cutting times, so as to obtain the initial cutting depth allocated to each workpiece position point of the original workpiece.

[0123] Through this embodiment, the minimum number of cutting times of the original workpiece is determined according to the maximum value of the second depth difference among the second depth differences. Then, the minimum number of cutting times of the original workpiece and the second depth difference corresponding to each workpiece position point of the original workpiece are used to accurately determine the initial cutting depth of each workpiece position point of the original workpiece. In this way, it can be ensured that the carrying capacity of the machine tool and the tool will not be exceeded during the cutting process, thereby improving cutting safety.

[0124] It should be clear that the present invention is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present invention.

[0125] It should also be noted that the exemplary embodiments mentioned in the present invention describe some methods or systems based on a series of steps or devices. However, the present invention is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiments, or in a different order from the embodiments, or several steps can be performed simultaneously.

[0126] The above is only a specific implementation of the present invention. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the system, module and unit described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be covered within the protection scope of the present invention.

Claims

1. A tool path planning method for a CNC vertical machining center, characterized in that: The method comprises: Acquire first contour information of a target workpiece and second contour information of an original workpiece, wherein the target workpiece is used to characterize an ideal workpiece expected to be obtained after cutting, and the original workpiece is used to characterize an actual workpiece to be cut; Determine the local contour complexity corresponding to each workpiece position point in the original workpiece by using the second contour information; Based on the first contour information and the complexity of each of the local contours, the initial cutting parameters of each of the workpiece position points in the original workpiece are corrected to obtain the actual cutting parameters of each of the workpiece position points in the original workpiece; Planning a tool trajectory for each of the workpiece position points in the original workpiece based on the actual cutting parameters of each of the workpiece position points in the original workpiece; The cutting parameters include cutting depth; based on the first contour information and the complexity of each local contour, the initial cutting parameters of each workpiece position point in the original workpiece are corrected to obtain the actual cutting parameters of each workpiece position point in the original workpiece, including: Determine a first depth difference between a target workpiece position point in the original workpiece and a corresponding workpiece position point in the target workpiece using the first contour information; The first depth difference is divided by the local contour complexity corresponding to the target workpiece position point and then normalized to obtain a first correction weight corresponding to the cutting depth; Multiplying the initial cutting depth of the target workpiece position point in the original workpiece by the first correction weight to obtain a target actual cutting depth of the target workpiece position point in the original workpiece; The cutting parameters include cutting speed; based on the first contour information and the complexity of each local contour, the initial cutting parameters of each workpiece position point in the original workpiece are corrected to obtain the actual cutting parameters of each workpiece position point in the original workpiece, including: Based on the local contour complexity corresponding to the target workpiece position point, the initial cutting speed corresponding to the target workpiece position point is corrected to obtain a theoretical cutting speed; Based on the first contour information and the theoretical cutting speed, construct a speed optimization function corresponding to the target workpiece position point; The speed optimization function is used to determine the target actual cutting speed corresponding to the target workpiece position point.

2. The tool path planning method for a CNC vertical machining center according to claim 1, characterized in that: The using the second contour information to determine the local contour complexity corresponding to each workpiece position point in the original workpiece includes: Based on the second contour information, taking the target workpiece position point in the original workpiece as the center, extending N workpiece position points to the left and right sides respectively, to construct a local area of ​​the target workpiece position point, where N is a positive integer; Acquire a first slope of a first curve formed by N workpiece position points on the left side of the target workpiece position point in the local area, and acquire a second slope of a second curve formed by N workpiece position points on the right side of the target workpiece position point in the local area; The local contour complexity corresponding to the target workpiece position point is determined by using the first slope and the second slope.

3. The tool path planning method for a CNC vertical machining center according to claim 2, characterized in that: The determining the local contour complexity corresponding to the target workpiece position point by using the first slope and the second slope includes: Square the difference between the first slope and the second slope to obtain a first calculated value; Square the sum of the absolute value of the first slope and the absolute value of the second slope to obtain a second calculated value; The cumulative value of the first calculated value and the second calculated value is squared to obtain the local contour complexity corresponding to the target workpiece position point.

4. The tool path planning method for a CNC vertical machining center according to claim 1, characterized in that: The method of correcting the initial cutting speed corresponding to the target workpiece position point based on the local contour complexity corresponding to the target workpiece position point to obtain a theoretical cutting speed includes: Performing normalized calculation on the local contour complexity corresponding to the target workpiece position point to obtain a normalized contour complexity; Determining a second correction weight corresponding to the cutting speed by using the normalized profile complexity; The initial cutting speed of the target workpiece position point in the original workpiece is multiplied by the second correction weight to obtain the theoretical cutting speed of the target workpiece position point in the original workpiece.

5. The tool path planning method for a CNC vertical machining center according to claim 1, characterized in that: The constructing a speed optimization function corresponding to the target workpiece position point based on the first contour information and the theoretical cutting speed includes: Based on the first contour information, obtaining an absolute value of an actual cutting speed difference between each two adjacent workpiece position points in a local area corresponding to the target workpiece position point in the original workpiece; Accumulating the absolute values ​​of the actual cutting speed differences to obtain a target accumulated value; The actual cutting speed of the target workpiece position point is taken as the independent variable, and the absolute value of the difference between the actual cutting speed of the target workpiece position point and the theoretical cutting speed, multiplied by the target accumulated value, is taken as the dependent variable to construct the speed optimization function corresponding to the target workpiece position point.

6. The tool path planning method for a CNC vertical machining center according to claim 1, characterized in that: The method of using the speed optimization function to determine the target actual cutting speed corresponding to the target workpiece position point includes: Obtaining the actual cutting speed value range corresponding to the target workpiece position point; Within the actual cutting speed value range, the actual cutting speed corresponding to when the function value of the speed optimization function is minimum is determined as the target actual cutting speed corresponding to the target workpiece position point.

7. The tool path planning method for a CNC vertical machining center according to any one of claims 1 to 6, characterized in that: Before correcting the initial cutting parameters of each workpiece position point in the original workpiece based on the first contour information and each local contour complexity to obtain the actual cutting parameters of each workpiece position point in the original workpiece, the method further includes: Acquire a maximum cutting depth of the tool and a second depth difference between corresponding workpiece position points of the target workpiece and the initialized original workpiece; The maximum cutting depth and each of the second depth differences are used to determine the initial cutting depth of each of the workpiece position points in the original workpiece.

8. The tool path planning method for a CNC vertical machining center according to claim 7, characterized in that: The using the maximum cutting depth and each of the second depth differences to respectively determine the initial cutting depth of each of the workpiece position points in the original workpiece comprises: Obtaining a maximum second depth difference value among the second depth differences; Dividing the maximum value of the second depth difference by the maximum cutting depth to obtain the minimum number of cutting times of the original workpiece; Each of the second depth differences is divided by the minimum number of cutting times to obtain the initial cutting depth of each of the workpiece position points in the original workpiece.

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