Blade finish machining tool path planning method

Abstract

The invention provides a blade finish machining tool path planning method, and relates to the technical field of numerical control machining. The method comprises the steps that a parameterized curved surface model of a to-be-machined blade is obtained; based on the parameterized curved surface model, effective cutter contact evaluation indexes of the to-be-machined blade are calculated; wherein the effective cutter contact evaluation index comprises at least one of a distance threshold value between adjacent cutter contacts, a normal vector included angle threshold value and an azimuth angle included angle threshold value; and according to the effective cutter contact evaluation indexes, effective cutter contacts in the feeding direction of the blade to be machined are determined, and a blade cutter contact path is generated based on the effective cutter contacts. According to the method, geometric evaluation and screening are carried out on the cutter contacts in the feeding direction based on the blade parameterized curved surface model, so that the generated cutter contact path keeps continuity and curved surface adaptability in at least one geometric dimension, the cutter contact distribution keeps a reasonable level while the blade finish machining forming quality is ensured, and the blade finish machining quality is improved. And the processing efficiency can be improved.

Description

Technical Field

[0001] This disclosure relates to the field of CNC machining technology, and more specifically, to a tool path planning method for blade finishing. Background Technology

[0002] As a core component of turbomachinery such as aero engines, the machining quality of blades is closely related to the engine's performance. Similarly, in the CNC machining process of blades, the machining algorithms used by Computer-Aided Manufacturing (CAM) software play a decisive role in the machining efficiency and accuracy of the blades.

[0003] Blade surfaces are freeform surfaces. In freeform surface machining toolpath planning algorithms, the determination of machining step size and machining line spacing are important features that distinguish different machining algorithms. Machining line spacing typically describes the distance between corresponding tool contact points on two adjacent toolpath trajectories, while step size describes the straight-line distance between two adjacent tool contact points on the same continuous toolpath. While the selection methods for machining line spacing have been extensively studied in related research and engineering applications, systematic research on machining step size is relatively limited.

[0004] However, the selection of the machining step size directly affects the surface quality and machining efficiency of freeform surface finishing. When the machining step size is large, the distribution of tool points is relatively sparse, easily forming sharp, multifaceted features on the machined surface, affecting the forming quality of the freeform surface. Simultaneously, in areas with significant curvature changes, an excessively large feed step size may also lead to increased geometric changes between adjacent tool points, causing drastic changes in the tool axis posture, which in turn induces vibration and impact phenomena during machining, adversely affecting machining accuracy and stability. Conversely, when the machining step size is small, the distribution of tool points is denser, and the path shape is closer to the theoretical curve, which is beneficial for improving the continuity and smoothness of the machined surface. However, it also significantly increases the number of tool points and data processing volume, reducing machining efficiency and increasing machining costs.

[0005] Therefore, in the precision machining of free-form surface components such as blades, how to achieve a reasonable balance between machining efficiency and machining quality remains a technical issue that urgently needs attention and improvement in the machining step length planning of the blade feed direction.

[0006] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0007] The purpose of this disclosure is to provide a tool path planning method for blade finishing, thereby solving, to at least some extent, the problem in the related art that the machining step length in the blade feed direction is difficult to balance machining efficiency and machining quality.

[0008] According to a first aspect of this disclosure, a toolpath planning method for blade finishing is provided, comprising: Obtain the parametric surface model of the blade to be processed; Based on the parametric surface model, the effective tool contact point evaluation index of the blade to be processed is calculated; wherein, the effective tool contact point evaluation index includes at least one of the following: distance threshold between adjacent tool contacts, normal vector angle threshold, and azimuth angle threshold; The effective tool contact points in the feed direction of the blade to be processed are determined according to the effective tool contact point evaluation index, and the blade tool contact point path is generated based on the effective tool contact points.

[0009] In one exemplary embodiment of this disclosure, calculating the effective tool contact point evaluation index of the blade to be processed based on the parameterized surface model includes: Based on the parametric surface model, the geometric distribution characteristics of the blade to be processed are determined, and the effective tool contact point evaluation index of the blade to be processed is calculated based on the geometric distribution characteristics. The geometric distribution features include at least one of spatial position distribution, normal vector distribution, and azimuth distribution; the effective tool contact evaluation index includes at least one of the following: a distance threshold between adjacent tool contacts determined based on the spatial position distribution of the parametric surface model in the feed direction of the blade to be processed, a normal vector angle threshold between adjacent tool contacts determined based on the normal vector distribution on the parametric surface model, and an azimuth angle threshold between adjacent tool contacts determined based on the azimuth distribution of the parametric surface model in a preset reference plane.

[0010] In one exemplary embodiment of this disclosure, determining the distance threshold between adjacent blade contacts includes: Based on the parametric surface model, a surface section line representing the blade processing range is extracted in the feed direction of the blade to be processed; Calculate the length parameter of the curved section line within the blade processing range, and determine the distance threshold between adjacent tool contact points based on the length parameter and the preset curved section point density.

[0011] In one exemplary embodiment of this disclosure, determining the threshold of the normal vector angle between the adjacent blade contacts includes: Determine the normal vector distribution on the parameterized surface model, and determine the normal vector angle subdivision parameters based on the normal vector distribution; Based on the normal vector angle subdivision parameters and combined with the preset first angle mapping relationship, the threshold of the normal vector angle between adjacent blade contacts is determined.

[0012] In one exemplary embodiment of this disclosure, determining the azimuth angle threshold between the adjacent blade contacts includes: The parametric surface model is mapped to the preset reference plane to obtain the orientation distribution of the parametric surface model in the preset reference plane, and the azimuth subdivision parameters are determined based on the orientation distribution. Based on the azimuth subdivision parameters and combined with the preset second angle mapping relationship, the azimuth angle threshold between adjacent blade contacts is determined.

[0013] In an exemplary embodiment of this disclosure, determining the effective tool contact points in the feed direction of the blade to be processed according to the effective tool contact point evaluation index, and generating a blade tool contact point path based on the effective tool contact points, includes: The current tool contact point is determined in the feed direction of the blade to be processed, and the geometric parameters corresponding to the current tool contact point are calculated based on the parameterized surface model. Based on the geometric parameters of the current cutter contact and the determined geometric parameters of the previous cutter contact, calculate the parameter change corresponding to the effective cutter contact evaluation index; The parameter change is compared with the effective contact evaluation index to determine whether the current contact is an effective contact. If the current tool contact point is determined to be a valid tool contact point, iterative updates are performed along the feed direction of the blade to be processed to generate the blade tool contact point path.

[0014] In one exemplary embodiment of this disclosure, the geometric parameters include at least one of spatial position, normal vector, and azimuth angle; The calculation of the geometric parameters corresponding to the current tool contact point based on the parametric surface model includes: At the start of tool contact path planning, initialize the feed parameters and the geometric parameters of the previous tool contact; The current feed parameters are updated based on the feed parameters corresponding to the previous cutter contact and the preset feed step size. Substitute the current feed parameters into the parameterized surface model to determine the surface parameter position corresponding to the current tool contact point, and calculate the spatial position of the current tool contact point based on the surface parameter position; and / or Based on the surface normal vector function defined in the parameterized surface model, the normal vector of the current tool contact point is obtained at the surface parameter position corresponding to the current tool contact point; and / or Calculate the azimuth angle corresponding to the current blade contact point based on its spatial position.

[0015] In an exemplary embodiment of this disclosure, calculating the parameter change corresponding to the effective tool contact evaluation index based on the geometric parameters of the current tool contact and the determined geometric parameters of the previous tool contact includes: Based on the geometric parameters of the current cutter contact and the geometric parameters of the previous cutter contact, calculate at least one of the following parameter changes between the current cutter contact and the previous cutter contact: the change in distance, the change in the normal vector angle, and the change in the azimuth angle. These parameters are used as the parameter changes corresponding to the effective cutter contact evaluation index.

[0016] In an exemplary embodiment of this disclosure, comparing the parameter change with the effective cutting contact evaluation index to determine whether the current cutting contact is an effective cutting contact includes: Based on the effective knife contact evaluation index, at least one tolerance is determined among the distance tolerance, normal vector angle tolerance, and azimuth angle tolerance between the current knife contact and the previous knife contact. Based on the effective knife contact evaluation index and the corresponding tolerance, a reference range for the parameter variation is constructed; The parameter change is compared with the reference range. If the parameter change falls within the reference range, the current tool contact is determined to be a valid tool contact.

[0017] In one exemplary embodiment of this disclosure, the step of iteratively updating along the feed direction of the blade to be processed to generate the blade blade contact path when the current blade contact point is determined to be a valid blade contact point includes: If the current cutter contact is determined to be a valid cutter contact, the current cutter contact is updated to the new previous cutter contact; Based on the updated previous cutter contact point, a new current cutter contact point is determined along the feed direction of the blade to be processed, and the parameter change calculation and cutter contact point validity determination steps are repeated until the blade cutter contact point path is generated.

[0018] According to a second aspect of this disclosure, a toolpath planning device for blade finishing is provided, comprising: The blade surface acquisition module is used to acquire the parametric surface model of the blade to be processed. The evaluation index calculation module is used to calculate the effective tool contact point evaluation index of the blade to be processed based on the parametric surface model; wherein, the effective tool contact point evaluation index includes at least one of the following: distance threshold between adjacent tool contacts, normal vector angle threshold, and azimuth angle threshold. The processing path determination module is used to determine the effective tool contact points in the feed direction of the blade to be processed according to the effective tool contact point evaluation index, and generate the blade tool contact point path based on the effective tool contact points.

[0019] According to a third aspect of this disclosure, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processing unit, implements the blade finishing toolpath planning method described in any of the preceding claims.

[0020] According to a fourth aspect of this disclosure, an electronic device is provided, comprising: A processing unit; and a storage unit for storing executable instructions of the processing unit; wherein the processing unit is configured to execute the blade finishing toolpath planning method described above by executing the executable instructions.

[0021] The exemplary embodiments disclosed herein may have some or all of the following beneficial effects: In the blade finishing toolpath planning method provided in the exemplary embodiments of this disclosure, an effective tool contact point evaluation index is calculated based on the parametric surface model of the blade, and the effective tool contact point evaluation index is used to determine the tool contact points in the feed direction. This constrains the geometric changes of the tool contact points used for path generation in at least one dimension, including spatial position, surface normal vector, and reference direction. As a result, the generated tool contact point path maintains continuity in overall geometry, thereby providing a stable geometric basis for the forming quality of the blade surface during the finishing process.

[0022] Furthermore, since the tool contact path is composed of effective tool contact points that meet the effective tool contact evaluation index, the distribution of effective tool contact points in the feed direction can change with the geometric characteristics of the blade surface. This allows the distribution of effective tool contact points in different surface regions to exhibit a state that adapts to the local geometric characteristics, thus demonstrating the following characteristics of the blade's freeform surface geometry at the path level.

[0023] Furthermore, by generating blade tool contact paths based on effective tool contact points, it is not necessary to use a fixed feed step size to describe all curved surface areas during the path generation process. While ensuring the geometric continuity of the tool contact path, the number of unnecessary tool contact points is reduced, thereby maintaining a reasonable level of data scale and path complexity in the generated tool contact path, which is conducive to improving the overall processing efficiency in the finishing stage.

[0024] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0026] Figure 1 A schematic diagram of a system architecture for a blade finishing toolpath planning method applicable to embodiments of the present disclosure is shown.

[0027] Figure 2 A flowchart illustrating a blade finishing tool path planning method according to an embodiment of this disclosure is shown.

[0028] Figure 3 A schematic diagram illustrating the modeling process of a parametric surface model of a bladed disk in an embodiment of this disclosure is shown.

[0029] Figure 4 A schematic diagram illustrating the modeling process of a parametric surface model of an impeller blade according to an embodiment of this disclosure is shown.

[0030] Figure 5 A flowchart illustrating a method for determining a distance threshold between adjacent blade contacts is shown in an embodiment of this disclosure.

[0031] Figure 6 A cross-sectional schematic diagram of the curved surface of a bladed disk according to an embodiment of the present disclosure is shown.

[0032] Figure 7 A flowchart illustrating a method for determining a threshold value for the included angle between the normal vectors of adjacent blade contacts is shown in an embodiment of this disclosure.

[0033] Figure 8 A flowchart illustrating a method for determining the azimuth angle threshold between adjacent blade contacts is shown in an embodiment of this disclosure.

[0034] Figure 9 A schematic diagram of a process for generating blade contact paths is shown in an embodiment of this disclosure.

[0035] Figure 10 A schematic diagram of an initial blade contact point is shown in an embodiment of this disclosure.

[0036] Figure 11 A schematic diagram illustrating the principle of a blade finishing tool path planning method according to an embodiment of this disclosure is shown.

[0037] Figure 12 A schematic diagram of the blade contact path of a bladed disk in an embodiment of this disclosure is shown.

[0038] Figure 13 A partially enlarged schematic diagram of the blade contact path of a bladed disk according to an embodiment of this disclosure is shown.

[0039] Figure 14 A schematic diagram of another blade contact path of a bladed disk is shown in an embodiment of this disclosure.

[0040] Figure 15 An enlarged schematic diagram of the blade contact point path in the trailing edge region of a bladed disk according to an embodiment of this disclosure is shown.

[0041] Figure 16 A schematic diagram of the blade contact path of a bladed disk after ball-end blade conversion is shown in an embodiment of this disclosure.

[0042] Figure 17 A schematic diagram of an impeller blade cutter contact path is shown in an embodiment of this disclosure.

[0043] Figure 18 A schematic diagram of another impeller blade cutter contact path is shown in an embodiment of this disclosure.

[0044] Figure 19 A schematic diagram of the impeller blade cutter contact path after ball-end cutter conversion is shown in an embodiment of this disclosure.

[0045] Figure 20 A schematic diagram of another impeller blade cutter contact path based on ball-end cutter conversion is shown in an embodiment of this disclosure.

[0046] Figure 21 A schematic diagram of a blade finishing tool path planning device is shown in an embodiment of the present disclosure.

[0047] Figure 22 A schematic diagram of the structure of an electronic device suitable for implementing embodiments of the present disclosure is shown.

[0048] In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts. Detailed Implementation

[0049] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this disclosure more comprehensive and complete, and to fully convey the concept of the example embodiments to those skilled in the art. The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced with one or more of the specific details omitted, or other methods, components, apparatus, steps, etc., can be employed. In other instances, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0050] Furthermore, the accompanying drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0051] In toolpath planning for freeform surface finishing, the generation method of the tool contact point in the feed direction is one of the important factors affecting machining quality. The tool contact point refers to the location where the tool comes into contact with, or is considered to be in contact with, the target machined surface.

[0052] In related technologies, the generation of a single toolpath on a freeform surface is usually achieved by recursively generating adjacent tool contacts along the direction of the surface parameters, with the geometric error between adjacent tool contacts serving as the primary control criterion.

[0053] Specifically, one technical solution uses surface parameters as recursive variables. Starting from the initial tool contact point, it progressively calculates the positions of subsequent tool contact points according to preset parameter increments. It compares the calculated error—either the chord length error between adjacent tool contact points or the linear deviation introduced by the chord length—with a preset allowable error to determine if the current tool contact point meets the requirements. When the calculated error does not meet the constraints, the parameter increments are adjusted and the tool contact points are recalculated, thereby achieving the progressive generation of the toolpath.

[0054] Another type of technical solution is often used in five-axis freeform surface machining scenarios. It typically uses bow height error as the main evaluation indicator. This involves calculating the bow height error between adjacent tool contacts and comparing the calculated error with a preset allowable error to control the step distance between adjacent tool contacts. In this type of solution, the tool contact generation process usually involves repeatedly adjusting the step size parameter so that the calculated geometric error gradually approaches the allowable error, ultimately determining the position of adjacent tool contacts.

[0055] In addition, some technical solutions, based on the aforementioned error control, introduce step size correction coefficients or proportional adjustment methods to repeatedly correct parameter increments, thereby achieving recursive generation of the tool contact point in the feed direction. These methods generally still rely on a single geometric error as the primary criterion, constructing the toolpath through iterative iteration.

[0056] In summary, most existing methods for planning tool contacts in the feed direction of freeform surfaces rely on a single or limited geometric error index to evaluate adjacent tool contacts and generate paths by repeatedly adjusting parameter increments. In regions where the blade surface geometry is complex or curvature varies significantly, these methods often require frequent adjustments to the step size parameters to meet error constraints, thus increasing the number of tool contact calculations and the complexity of path generation. Conversely, in regions with relatively gentle surface changes, a mismatch between the tool contact distribution and the surface geometry can easily occur, affecting the overall quality of the machining path. Therefore, related technologies still face the challenge of balancing machining quality and efficiency in the process of tool contact planning in the feed direction.

[0057] To address one or more of the aforementioned technical problems, this disclosure provides a toolpath planning method for blade finishing. This method calculates an effective tool contact point evaluation index based on a parametric surface model of the blade, and uses this index to determine the tool contact points in the feed direction. This constrains the geometric changes of the tool contact points used for path generation in at least one dimension: spatial position, surface normal vector, and reference direction. The resulting tool contact point path maintains overall geometric continuity and adapts to the blade surface features. Furthermore, since the tool contact point path consists of effective tool contact points that meet the effective tool contact point evaluation index, the distribution of tool contact points in the feed direction can change with the surface geometry. This reduces the number of unnecessary tool contact points while ensuring path geometric continuity, thus maintaining a reasonable level of data scale and path complexity in the generated tool contact point path, which is beneficial for balancing machining quality and efficiency in the finishing stage.

[0058] refer to Figure 1 The diagram shows a system architecture diagram of a blade finishing toolpath planning method that can be applied to embodiments of the present disclosure.

[0059] exist Figure 1In this system architecture 100, one or more terminal devices such as a smartphone 101, a portable computer 102, and a desktop computer 103 may be included, along with a network 104 and a server 105. The network 104 serves as the medium for providing a communication link between the terminal devices and the server 105. The network 104 may include various connection types, such as wired or wireless communication links or fiber optic cables. The terminal devices may be various electronic devices with data processing capabilities, including a display screen that shows the user data related to the toolpath planning for blade finishing, such as, but not limited to, the parametric surface model of the blade to be processed, tool contact path data, and tool contact geometric parameters. These electronic devices include, but are not limited to, the aforementioned smartphone 101, portable computer 102, and desktop computer 103.

[0060] It should be understood that Figure 1 The number of terminal devices, networks, and servers shown is merely illustrative. Depending on implementation needs, there can be any number of terminal devices, networks, and servers. For example, server 105 could be a server cluster composed of multiple servers.

[0061] The blade finishing toolpath planning method provided in this embodiment is generally executed by a terminal device, and correspondingly, the blade finishing toolpath planning device is generally installed in the terminal device. However, it is readily understood by those skilled in the art that the blade finishing toolpath planning method provided in this embodiment can also be executed by a server 105, and correspondingly, the blade finishing toolpath planning device can also be installed in the server 105. This exemplary embodiment does not impose any special limitations on this.

[0062] This disclosure also provides an exemplary embodiment of a blade finishing toolpath planning method, referencing... Figure 2 As shown, the method may include the following steps S210 to S230: Step S210: Obtain the parametric surface model of the blade to be processed; Step S220: Based on the parametric surface model, calculate the effective tool contact point evaluation index of the blade to be processed; wherein, the effective tool contact point evaluation index includes at least one of the following: distance threshold between adjacent tool contacts, normal vector angle threshold, and azimuth angle threshold. Step S230: Determine the effective tool contact points in the feed direction of the blade to be processed according to the effective tool contact point evaluation index, and generate the blade tool contact point path based on the effective tool contact points.

[0063] The tool path planning method for blade finishing in this example embodiment will now be described in detail.

[0064] In step S210, the parametric surface model of the blade to be processed is obtained.

[0065] The parametric surface model is used to mathematically describe the three-dimensional geometry of the blade to be machined, facilitating subsequent calculations of the position of the tool contact point and related geometric parameters on the blade surface. The parametric surface model can be directly provided by a computer-aided design system, obtained from existing blade geometric data through analysis, transformation, or reconstruction, or simplified, reparameterized, or precision-adjusted versions of existing surface models to meet different machining accuracy or computational efficiency requirements.

[0066] In some example implementations, the parametric surface model can be represented mathematically with surface parameters as independent variables, so that the position of any point on the surface of the blade to be processed can be determined by the corresponding surface parameters. Through this parametric expression, the three-dimensional geometry of the blade to be processed can be mapped to the surface parameter space, thereby facilitating the calculation and analysis of the position of the tool contact point and related geometric parameters on the surface of the blade to be processed.

[0067] For example, parametric surface models can be modeled using spline surfaces such as NURBS (Non-Uniform Rational B-Spline) surfaces. NURBS surfaces have good geometric expressive power and flexibility, and can accurately represent free-form surfaces and their local curvature variation characteristics, thus making them suitable for the geometric modeling needs of free-form surface components such as blades.

[0068] For example, the parametric surface model of the blade to be processed is: in, S ( u , v ) indicates that the surface of the blade to be processed is in the parameter pair ( u , v The corresponding surface point at () N i，p ( u ) indicates the surface parameters u The first direction i indivual p B-spline basis functions; N j，q ( v ) indicates the surface parameters v The first direction j indivual q B-spline basis functions; w i，j Represents surface control points P i，j Weights; surface control points P i，j Indicates control of the ( i, j The coordinates of the control points at each location; m and n These represent the surface parameters respectively. u and v Number of control points in the direction.

[0069] It should be noted that surface control points are used to control the overall shape and local variations of the surface, and their spatial location does not necessarily need to be located on the surface. This parametric surface model takes the set of control points and their weights as input, and uses basis functions to weight and combine the control points, thereby achieving different parameter pairs ( u , v Generate the corresponding surface points. S ( u , v This allows for the continuous representation of the curved surface of the blade to be processed.

[0070] Of course, the parametric surface model can also adopt piecewise parametric surface or other equivalent parametric surface expression forms, as long as it can continuously and stably represent the spatial position of the blade surface to be processed in the surface parameter space and support the calculation of relevant geometric parameters. This disclosure does not limit the specific expression form of the parametric surface model.

[0071] refer to Figure 3 The diagram illustrates the modeling process of a parametric surface model for an impeller blade. 301 represents the distribution of discrete points on the impeller blade surface. These discrete points can be obtained by sampling the three-dimensional geometric model of the impeller blade, such as by regularly or irregularly sampling the impeller blade surface along the spanwise and chordwise directions to form a set of discrete points for surface reconstruction. 302 represents the parametric surface model of the impeller blade obtained by parametric fitting of the discrete points, such as using NURBS surfaces.

[0072] refer to Figure 4 The diagram illustrates the modeling process of a parametric surface model for an impeller blade. 401 represents the distribution of discrete points on the impeller blade surface, which can be obtained by sampling the three-dimensional geometric model of the impeller blade. 402 represents the parametric surface model of the impeller blade constructed by parametrically fitting the discrete points of the impeller blade surface.

[0073] This step, by acquiring a parametric surface model, provides a unified geometric basis for subsequent calculation of effective tool contact point evaluation indicators based on the surface geometric distribution characteristics and for determining the tool contact points in the feed direction of the blade to be processed, thereby supporting the development of the tool path planning process for blade finishing.

[0074] In step S220, based on the parametric surface model, the effective tool contact point evaluation index of the blade to be processed is calculated; wherein, the effective tool contact point evaluation index includes at least one of the following: the distance threshold between adjacent tool contacts, the normal vector angle threshold, and the azimuth angle threshold.

[0075] Effective tool contact evaluation indicators are used to characterize the degree of geometric change between adjacent tool contacts in the feed direction, providing a basis for the determination of subsequent tool contacts and the generation of blade tool contact paths. For example, the feed direction can be a preset machining direction or scanning direction along the blade surface to ensure the continuity and orderliness of the tool contact generation process on the blade surface.

[0076] Specifically, the distance threshold between adjacent tool contacts is used to limit the range of distance variation between adjacent tool contacts in space. The normal vector angle threshold is used to limit the angular variation between the surface normal vectors at adjacent tool contacts. The azimuth angle threshold is used to limit the range of angular variation between adjacent tool contacts relative to a preset reference direction. The preset reference direction refers to the directional reference determined in advance during toolpath planning and used to calculate the azimuth variation of adjacent tool contacts. The preset reference direction remains consistent within the same toolpath segment or the same comparison process and can be one of the following: a fixed direction in the machining coordinate system, the feed direction of the toolpath, the direction of surface parameters, or a direction determined by the geometric characteristics of the surface.

[0077] Understandably, various effective tool contact evaluation indicators can be used individually or in combination according to actual processing needs to constrain the geometric relationship between tool contacts in multiple dimensions.

[0078] In this step, by calculating the effective tool contact evaluation index based on the parametric surface model, an evaluation benchmark corresponding to the overall geometry of the blade can be obtained without relying on the specific tool contact generation result, providing a unified geometric reference condition for subsequent determination of the effectiveness of the tool contact in the feed direction.

[0079] In some example implementations, the geometric distribution characteristics of the blade to be processed can be determined based on a parametric surface model, and the effective blade contact point evaluation index of the blade to be processed can be calculated based on the geometric distribution characteristics.

[0080] Among them, geometric distribution features are used to characterize the geometric changes of the blade surface to be processed within a global or local region. Geometric distribution features can include at least one of spatial position distribution, normal vector distribution, and orientation distribution. Spatial position distribution refers to the relative positional relationship of different points on the blade surface to be processed in three-dimensional space. Normal vector distribution refers to the directional changes of the surface normal vector at different positions on the blade surface to be processed. Orientation distribution refers to the directional distribution and changes of different points on the blade surface to be processed relative to a preset reference direction.

[0081] By analyzing the parametric surface model, we can obtain the spatial shape, surface orientation, and changes relative to the preset reference direction of the blade surface at different parameter positions, thereby forming a comprehensive description of the blade's geometric characteristics.

[0082] Based on this, the effective cutting edge contact point evaluation index of the blade to be processed can be determined according to its geometric distribution characteristics. Specifically, the effective cutting edge contact point evaluation index may include at least one of the following: The distance threshold between adjacent tool contacts, determined by the spatial position distribution of the blade in the feed direction based on the parametric surface model, is used to limit the spatial interval between adjacent tool contacts in the feed direction.

[0083] The threshold of the angle between the normal vectors between adjacent tool contacts, determined by the normal vector distribution on the parametric surface model, is used to limit the allowable range of surface orientation changes at adjacent tool contacts.

[0084] The azimuth angle threshold between adjacent tool contacts, determined by the orientation distribution of the parametric surface model within a preset reference plane, is used to limit the range of angular variation of adjacent tool contacts relative to the preset reference direction.

[0085] For example, the distance threshold between adjacent tool contacts can be the maximum chord length threshold between adjacent tool contacts, used to constrain the fit between the approximate path formed by the linear connection of adjacent tool contacts and the theoretical surface. The normal vector angle threshold between adjacent tool contacts can be the maximum normal vector angle threshold between adjacent tool contacts, used to reflect the influence of surface curvature changes on tool attitude changes and to constrain the amplitude of tool axis changes in the pitch direction. The azimuth angle threshold between adjacent tool contacts can be the maximum azimuth angle threshold between adjacent tool contacts, used to constrain the swing amplitude of the tool axis in the lateral direction.

[0086] By correlating the geometric distribution characteristics of the blade to be processed with the effective tool contact evaluation index in the above manner, a benchmark condition for evaluating the geometric changes of adjacent tool contacts can be established at the overall curved surface level, thereby providing a geometric basis for subsequent determination of the effectiveness of tool contacts along the feed direction and generation of tool contact paths.

[0087] Based on this, this disclosure sets out multiple evaluation indicators for the changes between adjacent tool contacts, judging the quality of the currently planned tool contacts from different geometric dimensions such as spatial position, surface normal vector, and preset reference direction. This ensures that whether a tool contact participates in path generation no longer depends on a single geometric quantity, but is determined based on the comprehensive evaluation results of multi-dimensional geometric changes. Through the above judgment method, the tool contacts used to form the tool contact path remain under controlled geometric changes, thereby providing more stable geometric support conditions for the blade surface finishing process at the path level.

[0088] In some example implementations, references Figure 5 As shown, the process of determining the distance threshold between adjacent blade contacts may include steps S510 and S520: Step S510: Based on the parametric surface model, extract the surface section line representing the processing range of the blade in the feed direction of the blade to be processed.

[0089] The blade machining zone refers to the curved surface area of ​​the blade to be machined that requires finishing treatment, and it corresponds to a certain starting and ending position in the feed direction. The surface section line is used to reflect the spatial shape change of the blade to be machined in the feed direction within the blade machining zone, and it corresponds to the surface geometry on which the tool contact point is gradually distributed along the feed direction during the blade finishing process.

[0090] Specifically, in the parametric surface model, the corresponding parameter direction can be determined according to the feed direction of the blade to be processed, and the surface can be subjected to equal parameter values ​​or truncation operations in the parameter direction to obtain the surface cross-section line located within the blade processing range and extending along the feed direction.

[0091] For example, when a parametric surface model is defined with surface parameters u and v When representing the surface of a blade to be machined, if the feed direction of the blade corresponds to the surface parameters... u The direction of change can be determined by fixing the surface parameters. v Under the condition of surface parameters u By continuously taking values, a number of isoparametric lines extending along the feed direction are obtained, which serve as the surface section lines.

[0092] refer to Figure 6 As shown, a schematic cross-sectional view of the curved surface of a bladed disk is illustrated. Figure 6 Multiple curved section lines are schematically marked along the blade feed direction to characterize the geometric development of the blade surface in the feed direction. Among them, 601 is the first section line located at the beginning of the blade processing section, 602 is the last section line located at the end of the blade processing section, and the remaining curved section lines are located between the first section line 601 and the last section line 602.

[0093] It can be seen that the first section line 601 and the last section line 602 together define the processing range involved in the blade finishing process, thus providing boundary conditions for the subsequent description of the surface geometry within this processing range.

[0094] By extracting the surface section line corresponding to the blade processing section in the feed direction of the blade to be processed, the complex three-dimensional surface geometry problem of the blade can be transformed into a one-dimensional geometric scale description along the feed direction, thus providing a reference object for determining the distance threshold between adjacent tool contact points.

[0095] Step S520: Calculate the length parameter of the curved section line within the blade machining range, and determine the distance threshold between adjacent tool contact points based on the length parameter and the preset curved section point density.

[0096] In this step, the length parameter is used to characterize the geometric scale of the blade surface to be processed in the feed direction within the blade processing range, and the point density of the surface cross section is used to limit the fineness of the distribution of the tool contact points in the feed direction under this geometric scale condition.

[0097] For example, the length parameter can refer to the cumulative chord length along the curved surface section line between the first and last section lines, reflecting the actual curved surface length of the blade after unfolding along the feed direction within the blade machining zone. It can also be understood that the length parameter can be the range of variation of the curved surface parameter corresponding to the feed direction within the machining zone, and can be obtained by accumulating the distances between discrete sampling points on the curved surface section line, thus characterizing the geometric scale of the blade machining zone in the feed direction from different perspectives.

[0098] The point density of a curved surface section refers to the number of tool contacts per unit geometric length along the feed direction within the blade machining area. A higher point density indicates that, under the same geometric dimensions, more tool contacts need to be arranged in the feed direction, relatively reducing the spacing between adjacent tool contacts to accommodate areas with complex surface geometry. Conversely, a lower point density indicates that fewer tool contacts are allowed to describe the blade machining area in the feed direction, relatively increasing the spacing between adjacent tool contacts to accommodate areas with relatively gentle surface geometry.

[0099] By correlating the length parameter with the point density of the curved surface section, a distance threshold can be obtained to constrain the spatial spacing between adjacent tool contacts, so that the distribution of adjacent tool contacts in the feed direction can match the geometry of the blade machining area.

[0100] In some example implementations, the distance threshold between adjacent tool contacts can be the maximum chord length threshold between adjacent tool contacts, specifically: dis_del = arc_length / density in, dis_del The maximum chord length threshold between adjacent knife contacts. arc_length The cumulative chord length of the blade's front and rear cross sections. density The preset point density of the curved surface section can be set to a value greater than or equal to 60.

[0101] Cumulative chord length of the blade's first and last cross sections arc_length The calculation process is as follows: For the curved surface of the blade to be processed, in order to facilitate the calculation of the arc length of the surface, the surface can be represented as: S ( u , v )=( x ( u , v ), y ( u , v ), z ( u , v )) in, x ( u , v ), y ( u , v )and z ( u , v ) represent the spatial position components of the surface along each coordinate axis in a three-dimensional Cartesian coordinate system.

[0102] When one of the surface parameters is fixed, such as setting the surface parameter... v Take as a constant v 0, the surface in v = v Under condition 0, it becomes a line about the surface parameters. u The curve, which is a cross-sectional line of a surface, can be represented as: S ( u , v 0)=( x ( u , v 0), y ( u , v 0), z ( u , v 0)) For this curved section line, its surface parameters u The tangent vector at a point can be expressed as a function of the surface parameters. u First derivative: dS / du Correspondingly, the curve section line is within the range of surface parameters [ a , b The cumulative chord length of the blade's first and last cross-sections within the [section] arc_ lengthfor: It should be noted that the cumulative chord length of the blade's first and last cross-sections... arc _ length In this embodiment, the arc-length integral is used to obtain the length of the cross-section of the curve within a continuous parameter domain. This is achieved when the point density of the curved surface cross-section... density When the value of is sufficiently large, the result of the arc length integral can be used as an approximation of the cumulative chord length obtained by linearly connecting adjacent cross-section points.

[0103] This embodiment allows for the determination of the distance threshold between adjacent blade contacts based on the overall geometric features of the blade, without relying on the specific location of the blade contact. This provides a basis for subsequent validity determination of the blade contacts based on the distance threshold.

[0104] In some example implementations, references Figure 7 As shown, the process of determining the threshold of the normal vector angle between adjacent blade contacts may include steps S710 and S720: Step S710: Determine the normal vector distribution on the parametric surface model, and determine the normal vector angle subdivision parameters based on the normal vector distribution.

[0105] Specifically, for the parameterized surface model of the blade to be processed, multiple parameter position points are selected within the surface parameter domain to represent the corresponding positions of the tool contact points in the parameterized surface model. These parameter position points can be sampling points uniformly distributed along the parameter direction, sampling points that correspond one-to-one with candidate tool contact points, or sampling points adaptively selected based on surface geometric changes to ensure coverage of both overall and local surface features.

[0106] The corresponding surface normal vectors are obtained at each parameter location point, forming a normal vector set. This normal vector set can describe the normal characteristics of the blade surface to be processed at different parameter locations. By analyzing the distribution of the normal vector set within the surface parameter domain, the normal vector distribution is determined. Specifically, the normal vector distribution can be reflected in the magnitude of the change in normal vector direction, the continuity of the change, and the spatial distribution characteristics of the change within the parameter domain. Through the normal vector distribution, regions with relatively gentle changes in normal vector direction and regions with relatively drastic changes in normal vector direction can be distinguished, thus reflecting the geometric complexity of the surface in different regions.

[0107] Furthermore, the subdivision parameter of the normal vector angle can be determined based on the distribution of the normal vector. The subdivision parameter describes the discrete granularity of the change in the normal vector direction and is used to classify the change in the normal vector direction into different levels of change. For example, regions with more dramatic changes in the normal vector direction correspond to higher subdivision levels, while regions with more gradual changes in the normal vector direction correspond to lower subdivision levels.

[0108] The normal vector angle subdivision parameters may include the number of subdivision levels of the normal vector direction change, the angle change range corresponding to each subdivision level, or classification rules used to distinguish different levels of normal vector change.

[0109] By setting the normal vector angle subdivision parameter, a graded description of the degree of change of normal vector in different regions of the blade surface to be machined can be achieved, providing a parameter basis for subsequent determination of adjacent tool contact points based on the normal vector angle threshold.

[0110] Step S720: Based on the normal vector angle subdivision parameters and combined with the preset first angle mapping relationship, determine the threshold of the normal vector angle between adjacent tool contacts.

[0111] The first angle mapping relationship is used to map the normal vector angle subdivision parameter to a specific normal vector included angle threshold.

[0112] Optionally, the first angle mapping relationship can be a lookup table mapping relationship, a piecewise mapping relationship, or a preset rule mapping relationship, where different levels of normal vector change correspond to different angle threshold settings. For example, in areas where the normal vector direction changes relatively gently, a larger normal vector angle threshold can be set; in areas where the normal vector direction changes more drastically, a smaller normal vector angle threshold can be set, thereby matching the threshold configuration with the local geometric characteristics of the surface.

[0113] For example, the threshold for the included angle of the normal vector between adjacent tool contacts can be the threshold for the maximum included angle of the normal vector between adjacent tool contacts, as follows: nor _ del=Pi / (25×((100+( ang_tess- 100)×3 / 8) / 100)) in, nor _ del The threshold value is the maximum normal vector angle between adjacent knife contacts. Pi This represents an approximate value of pi. ang_tess This refers to the subdivision parameter of the normal vector angle, which is the number of levels to which the included angle of the normal vector between adjacent tool contacts is subdivided. It can be understood that this formula is an illustrative implementation of the first angle mapping relationship, used to map the normal vector angle subdivision parameter to the corresponding normal vector angle threshold.

[0114] In some example implementations, references Figure 8 As shown, the process of determining the azimuth angle threshold between adjacent blade contacts may include steps S810 and S820: Step S810: Map the parametric surface model to a preset reference plane to obtain the orientation distribution of the parametric surface model in the preset reference plane, and determine the azimuth subdivision parameters based on the orientation distribution.

[0115] Specifically, for the parametric surface model of the blade to be processed, a preset reference plane is selected as a unified orientation analysis benchmark to compare and analyze the changes of the tool contact point in the feed direction. The preset reference plane can be a fixed plane in the machining coordinate system, such as a plane associated with the machine tool coordinate system, the workpiece clamping coordinate system, or the tool axis reference direction, thereby ensuring that the subsequent orientation angle analysis has a consistent orientation reference direction in different machining areas and between different tool contact points.

[0116] After determining the preset reference plane, the parametric surface model can be mapped onto the preset reference plane. Specifically, the parameter position points related to the tool contact point on the parametric surface model can be transformed into the preset reference plane, so that the geometric position relationship of the blade surface to be processed in space is represented in two-dimensional form in the preset reference plane, thereby forming a two-dimensional position distribution corresponding to the parameter position points in the preset reference plane.

[0117] The orientation distribution can be determined based on the relative directional relationships between adjacent points in a two-dimensional positional distribution within a preset reference plane. For example, by analyzing the changes in the direction of the line connecting adjacent two-dimensional points relative to a preset direction within the preset reference plane, the orientation variation characteristics at different positions can be obtained, thereby forming the orientation distribution of the parametric surface model within the preset reference plane. The preset direction can be the projection direction of a fixed direction in the machining coordinate system onto the preset reference plane, the projection direction of the feed direction of the blade to be processed onto the preset reference plane, or one of other pre-defined directions.

[0118] By analyzing the orientation distribution, it is possible to distinguish between regions where the orientation of the blade surface to be processed changes relatively gently within the preset reference plane and regions where the orientation changes relatively complexly.

[0119] Furthermore, by analyzing the orientation distribution, the degree of dispersion of orientation changes in different regions is determined, and the azimuth subdivision parameters are determined accordingly. The azimuth subdivision parameters are used to divide the orientation changes of the blade surface to be processed within a preset reference plane into multiple azimuth change levels. For example, regions with more complex azimuth changes are assigned a higher subdivision level, while regions with gentler azimuth changes are assigned a lower subdivision level.

[0120] Azimuth subdivision parameters may include the number of subdivision levels of azimuth change, the azimuth range corresponding to each subdivision level, or classification rules used to distinguish different levels of azimuth change.

[0121] By setting azimuth subdivision parameters, the degree of azimuth variation of the blade surface to be processed in different regions within a preset reference plane can be classified and described, providing a parameter basis for determining the subsequent azimuth angle threshold.

[0122] Step S820: Based on the azimuth subdivision parameters and combined with the preset second angle mapping relationship, determine the azimuth angle threshold between adjacent tool contacts.

[0123] The second angle mapping relationship is used to establish the correspondence between the azimuth subdivision parameters and the azimuth angle threshold, so that the threshold can be adjusted according to the different characteristics of azimuth changes.

[0124] Specifically, after obtaining the azimuth subdivision parameters, the corresponding azimuth angle threshold can be configured for different azimuth change levels by combining the second angle mapping relationship. The second angle mapping relationship can be a preset rule mapping, segmented mapping, or lookup table mapping relationship, and its function is to convert the azimuth change level into a specific and usable azimuth angle threshold.

[0125] For example, in areas with relatively gentle azimuth changes, a relatively large azimuth angle threshold is configured to allow adjacent tool contacts to have a large range of directional changes within the reference plane, thereby avoiding unnecessary tool contact densification in areas with stable path orientation. In areas with more complex or frequent azimuth changes, a relatively small azimuth angle threshold is configured to strengthen the constraint on the directional changes of adjacent tool contacts, ensuring the continuity and stability of the tool contact path under planar projection.

[0126] For example, the azimuth angle threshold between adjacent tool contacts can be the maximum azimuth angle threshold between adjacent tool contacts, as follows: tab _ del= ( Pi / 90) / (0.01× tessvl ) in, tab _ del This is the threshold value for the maximum azimuth angle between adjacent knife contacts. Pi This is an approximation of pi. tessvl This is the azimuth subdivision parameter, used to represent the number of levels into which the azimuth angle variation range between adjacent tool contacts is subdivided. It can be understood that this formula is an illustrative implementation of the second angle mapping relationship, used to map the azimuth subdivision parameter to the corresponding azimuth angle threshold.

[0127] By introducing an azimuth subdivision parameter, the maximum azimuth angle threshold between adjacent tool contacts is adjusted accordingly based on the azimuth change level. When the azimuth subdivision parameter is larger, the corresponding maximum azimuth angle threshold is relatively smaller, thus imposing stricter constraints on the azimuth changes between adjacent tool contacts. When the azimuth subdivision parameter is smaller, the corresponding maximum azimuth angle threshold is relatively larger, thus allowing for a wider range of azimuth changes between adjacent tool contacts.

[0128] In step S230, the effective tool contact points in the feed direction of the blade to be processed are determined according to the effective tool contact point evaluation index, and the blade tool contact point path is generated based on the effective tool contact points.

[0129] In the toolpath planning process for blade finishing, candidate tool contacts can be sequentially determined along the feed direction of the blade to be machined. Combined with effective tool contact evaluation indicators, the geometric validity of these candidate tool contacts is determined. Geometric validity determination assesses whether the geometric changes between adjacent tool contacts satisfy the constraints defined by the effective tool contact evaluation indicators, thereby determining whether the current tool contact is a valid tool contact.

[0130] When a candidate cutter contact meets the evaluation criteria for an effective cutter contact, it is identified as an effective cutter contact and used in the construction of the blade cutter contact path. When a candidate cutter contact does not meet the evaluation criteria for an effective cutter contact, it is not included in the cutter contact path. In this way, a set of effective cutter contacts that meet geometric constraints can be obtained by screening along the feed direction of the blade to be processed.

[0131] Based on the effective tool contact points, they are connected in sequence along the feed direction of the blade to be machined, generating a tool contact path for blade finishing. The generated tool contact path can reflect the geometric features of the blade surface to be machined as a whole and provide a path basis for tool movement in subsequent CNC machining processes.

[0132] In some example implementations, references Figure 9 As shown, step S230 may further include steps S910 to S940: Step S910: Determine the current tool contact point in the feed direction of the blade to be processed, and calculate the geometric parameters corresponding to the current tool contact point based on the parametric surface model.

[0133] The geometric parameters include at least one of spatial position, normal vector, and azimuth angle. Spatial position represents the specific three-dimensional coordinate position of the tool contact point on the surface of the blade to be processed. Normal vector represents the normal direction of the blade surface at the tool contact point. Azimuth angle represents the directional characteristics of the tool contact point within a preset reference plane.

[0134] For example, at the start of tool contact path planning, the feed parameters and the geometric parameters of the previous tool contact are first initialized. If the previous tool contact can be a preset initial tool contact, its geometric parameters serve as the reference basis for subsequent tool contact calculations.

[0135] After initialization, the current feed parameters are updated along the feed direction of the blade to be processed, based on the feed parameters corresponding to the previous tool contact and the preset feed step size. The feed parameters can be surface parameters in the parametric surface model corresponding to the feed direction, and the feed step size is the parameter increment of this surface parameter during the generation process of adjacent tool contacts.

[0136] Next, the current feed parameters are substituted into the parametric surface model to determine the surface parameter position corresponding to the current tool contact point, and the spatial position of the current tool contact point in three-dimensional space is calculated based on the surface parameter position. Alternatively, the normal vector of the current tool contact point can be obtained at the surface parameter position corresponding to the current tool contact point based on the predefined surface normal vector function in the parametric surface model. Furthermore, the azimuth angle corresponding to the current tool contact point can be calculated based on the spatial position of the current tool contact point.

[0137] Specifically, the feed parameters are first initialized, including: initial feed parameters, denoted as... u _ old = upar The initial parameter for the feed direction is denoted as... u _ beg = u 0; Feed direction termination parameter, denoted as u _ end = u 1; The preset feed step size is del _ u = k 1×( u _ end - u _ beg ), representing the initial step feed amount in the feed direction, where k 1 represents the proportionality coefficient; for example, if it is set to 0.01, it means the feed step size. del _ u It can be adjusted according to actual needs.

[0138] Taking the calculation of the first tool path segment as an example, the surface parameters at this time are: u ( u = u 0) 、v Substituting 0 into the parametric surface model, we get: S ( u 0, v 0)=( x ( u 0,v 0), y ( u 0, v 0), z ( u 0, v 0)) in, pnt 1= S ( u 0, v 0) indicates the initial tool contact point. (See reference) Figure 10 As shown, a schematic diagram of an initial knife contact point is presented, where 1001 in the diagram represents the initial knife contact point.

[0139] nor 1 represents the normal vector at the initial blade contact point. First, we can calculate two partial derivative vectors: Then, the cross product of the two partial derivative vectors yields the normal vector at the initial knife contact point, i.e. nor 1= N ( u 0, v 0): Additionally, the azimuth angle of the initial tool contact point in the coordinate system tab 1 is: tab 1= atan 2( pnt 1(2), pnt 1(1)) in, pnt 1(1) pnt 1(2) represent the coordinate components of the initial tool contact point along the first coordinate axis (e.g., the X-axis) and the second coordinate axis (e.g., the Y-axis) in the coordinate system, respectively. atan 2() represents the arctangent function.

[0140] After calculating the geometric parameters of the initial tool contact point, the initial tool contact point is recorded as the previous tool contact point, i.e. xyz _ old = pnt 1; Correspondingly, the normal vector of the previous blade contact point is denoted as nor _ old = nor 1; The azimuth angle of the previous contact point is recorded as tab _ old = tab 1. Simultaneously, the generated initial tool contact data can be stored in the data manager.

[0141] Next, update the feed parameters corresponding to the previous contact point. upar = u _ old + del _ u And based on the updated feed parameters, calculate the relevant data for the next adjacent tool contact point. Specifically, substitute the updated feed parameters into the parametric surface model, and we have: xyz _ new = S ( upar , v 0) indicates the current tool contact point; nor _ new = N ( upar , v 0), representing the normal vector at the current tool contact point; tab _ new = atan 2( xyz _ new (2), xyz _ new (1) represents the azimuth angle of the current tool contact point in the coordinate system. Wherein, xyz _ new (2), xyz _ new (1) These represent the coordinate components of the current tool contact point along the first coordinate axis and the second coordinate axis in the coordinate system, respectively.

[0142] This step allows for the determination of the current tool contact point in the feed direction of the blade to be processed, and the acquisition of at least one geometric parameter corresponding to the current tool contact point, providing basic data for subsequent tool contact point validity determination and path iteration update.

[0143] Step S920: Based on the geometric parameters of the current tool contact and the determined geometric parameters of the previous tool contact, calculate the parameter change corresponding to the effective tool contact evaluation index.

[0144] For example, based on the geometric parameters of the current cutter contact and the previous cutter contact, at least one of the following parameter changes can be calculated as the change in distance between the current cutter contact and the previous cutter contact: the change in the normal vector angle and the change in the azimuth angle. This change can be used as the parameter change corresponding to the effective cutter contact evaluation index.

[0145] Specifically, after obtaining the geometric parameters of the current tool contact point, the geometric parameters of the previous tool contact point are retrieved, and the parameter change corresponding to the effective tool contact point evaluation index is calculated based on the comparison relationship between the two. The geometric parameters can include at least one of spatial position, normal vector, and azimuth angle. Therefore, the parameter change can also include at least one of distance change, normal vector angle change, and azimuth angle change, used to characterize the degree of geometric difference between adjacent tool contacts from different angles.

[0146] In some implementations, the calculation of parameter changes may include at least one of the following methods: Calculation of distance variation: When the effective contact point evaluation index is the distance threshold between adjacent contact points, the spatial distance between the current contact point and the previous contact point can be determined based on their spatial positions. This spatial distance is then used as the distance variation to characterize the spatial dispersion of adjacent contact points as they advance along the blade surface. A larger distance variation indicates a larger distance between adjacent contact points, and vice versa.

[0147] For example, the chord length between the current cutter contact point and the previous cutter contact point is: dis = distan ( xyz _ new , xyz _ old ) Calculation of the change in the angle between the normal vectors: When the effective tool contact evaluation index is the threshold of the angle between the normal vectors, the change in the angle between the normal vectors can be calculated based on the normal vectors at the current tool contact point and the normal vectors at the previous tool contact point.

[0148] The change in the included angle of the normal vector reflects the local geometric shape changes of the curved surface. In areas where the curved surface of the blade to be processed experiences sharp turns, twists, or changes in the normal direction, this change is usually larger; in areas where the curved surface is relatively flat, this change is usually smaller. By introducing the change in the included angle of the normal vector, the effectiveness determination of the tool contact point can consider not only the distance between the points but also the influence of the change in the normal direction of the curved surface on the machining trajectory.

[0149] For example, the angle between the normal vectors of the current tool contact point and the previous tool contact point: nor = angle ( nor _ new , nor _ old ) Calculation of azimuth angle change: When the effective tool contact evaluation index is the azimuth angle threshold, the azimuth angle change can be calculated based on the azimuth angle information of the current tool contact and the previous tool contact in the preset reference plane.

[0150] The change in azimuth angle reflects the directional change of the tool contact point path within the reference plane. In areas where the surface of the blade to be processed undergoes a significant turn or change in curve direction under planar projection, the change in azimuth angle is usually larger; in areas with a more consistent direction, the change in azimuth angle is usually smaller.

[0151] For example, it represents the azimuth angle between the current tool contact point and the previous tool contact point: tab = tab _ new - tab _ old It should be noted that the changes in distance, normal vector angle, and azimuth angle can be output individually as parameter changes, or they can be combined to form a set of parameter changes, which can then be used as input for the subsequent tool contact validity determination step. By calculating the changes in at least one of the above parameters, the geometric relationship between adjacent tool contacts can be described from dimensions such as spatial spacing, normal vector change, and planar orientation change, thereby providing data support for the selection of valid tool contacts.

[0152] Step S930: Compare the parameter change with the effective tool contact evaluation index to determine whether the current tool contact is an effective tool contact.

[0153] After obtaining the parameter change corresponding to the current tool contact, the parameter change is judged based on the pre-set effective tool contact evaluation index to determine whether the current tool contact meets the judgment condition of an effective tool contact.

[0154] In some example implementations, at least one tolerance among the following—distance tolerance, normal vector angle tolerance, and azimuth angle tolerance—can be determined based on effective tool contact evaluation metrics. Here, the tolerance represents the allowable range of minute variations in the step size during toolpath step size calculation, with the aim of improving the efficiency of tool contact generation while meeting blade machining accuracy requirements.

[0155] For example: dis_tol = k 2× dis_del nor_tol = k 2× nor _ del tab_tol = k 2× tab _ del in, dis_tol, nor_tol, tab_tolThese are the distance tolerance, the normal vector angle tolerance, and the azimuth angle tolerance, respectively. The distance tolerance, normal vector angle tolerance, and azimuth angle tolerance between adjacent tool contacts can be set to the same proportional coefficient. k 2. This allows for the determination of different types of parameter variations under a relatively consistent error scale. Of course, different proportional coefficients can also be set, and this disclosure does not limit this.

[0156] Next, based on the evaluation index of effective tool contact and the corresponding tolerance, a reference range for parameter variation is constructed. The reference range is used to characterize the allowable range that various parameter variations should meet when judged as effective tool contacts, and different reference range settings can be set for different types of parameter variations.

[0157] Finally, the parameter change is compared with the reference range. If the parameter change falls within the reference range, the current tool contact is determined to be a valid tool contact, balancing toolpath quality and toolpath generation efficiency. When the parameter change exceeds the corresponding reference range, the current tool contact is determined to be an invalid tool contact, or marked as a tool contact requiring further processing.

[0158] For example, when the parameter change is too large, that is, when the parameter change exceeds the upper limit threshold of the reference range: dis>(dis_del+dis_tol) nor>(nor_del+nor_tol) tab>(tab_del+tab_tol) In this situation, it can be determined that the current tool contact point exhibits significant variation in the feed direction or tool axis oscillation direction, which can easily affect machining quality. Therefore, the current tool contact point is deemed invalid. In this case, the feed step size can be reduced accordingly. del_ u This is to regenerate subsequent knife contacts.

[0159] For example, when the parameter change is too small, that is, when the parameter change rate is less than the lower limit of the reference range: dis<(dis_del-dis_tol) nor<(nor_del-nor_tol) tab<(tab_del-tab_tol) In this case, the change in the current tool contact point along the feed direction or tool axis oscillation direction is considered too small, resulting in reduced tool contact point generation efficiency, and thus it is identified as an invalid tool contact point. In this situation, the feed step size can be increased accordingly. del_u This is to improve the efficiency of subsequent blade contact generation.

[0160] In other words, this disclosure defines a tolerance, and determines that adjacent tool contacts meet the validity criteria when the calculated changes in relevant parameters of adjacent tool contacts are within the range of the benchmark threshold ± tolerance. This improves the overall efficiency of the toolpath generation process while ensuring the geometric quality of the toolpath.

[0161] Understandably, when parameter changes include multiple types of changes, each type of parameter change can be compared and judged separately, and the validity of the current tool contact can be determined comprehensively based on preset judgment rules. For example, the current tool contact can be determined as a valid tool contact when all parameter changes fall within the corresponding reference range, or when the reference range conditions for some parameter changes are met.

[0162] This step enables the determination of the effectiveness of the current tool contact based on the effective tool contact evaluation index, providing a basis for subsequent iterative updates of the tool contact path along the feed direction.

[0163] Step S940: If the current tool contact point is determined to be a valid tool contact point, iterative updates are performed along the feed direction of the blade to be processed to generate the blade tool contact point path.

[0164] Specifically, after determining the validity of the current tool contact and confirming that it is a valid tool contact, the relevant data of the valid tool contact is stored in the data manager to record the tool contact path generation result. Simultaneously, the index number of the current tool contact is updated to designate it as the new previous tool contact, serving as a reference for determining subsequent tool contacts.

[0165] Subsequently, based on the updated previous tool contact point, the calculation of parameter changes continues along the feed direction of the blade to be processed, thereby determining the new current tool contact point. The parameter change calculation and tool contact point validity determination steps are repeated to determine whether the new current tool contact point meets the preset validity conditions. When the new current tool contact point is determined to be a valid tool contact point, it is updated to the previous tool contact point again, and the iterative update continues along the feed direction until the planning of the current toolpath segment is completed.

[0166] Once the current toolpath segment is determined to be complete, based on the same tool contact generation method and judgment criteria as the current toolpath segment, the feed parameters and feed step size matching the next toolpath segment are determined, and the toolpath planning process for the next toolpath segment continues. There can be one or more toolpath segments, and the tool contact generation and judgment process is repeated for each toolpath segment in a preset order until the toolpath planning for all toolpath segments is completed.

[0167] This step involves iteratively generating the blade contact points point by point along the feed direction of the blade to be processed until a preset termination condition is met, thereby completing the generation of the blade contact point path. The termination condition can be reaching the blade boundary, completing the coverage of a preset processing area, or reaching the upper limit of a preset parameter range, etc., and this disclosure does not limit this to any specific condition.

[0168] In some example implementations, references Figure 11 The diagram illustrates the principle of a toolpath planning method for blade finishing. First, the first tool contact point is calculated using interpolation, and the corresponding geometric parameters, including spatial position, normal vector, and azimuth angle, are obtained and recorded as old data. xyz_old, nor_old, tab_old This serves as the baseline data for calculating the changes in subsequent adjacent blade contact points.

[0169] Based on this, the next adjacent tool contact point is calculated by interpolation according to the current feed parameters, and the corresponding geometric parameters are generated and recorded as the new spatial position. xyz_new Normal vector nor_new and azimuth tab_new .

[0170] Subsequently, based on the geometric parameters of the old and new tool contacts, the parameter changes between adjacent tool contacts are constructed, including the changes in distance between adjacent tool contacts. dis Change in the angle between the normal vectors nor and the change in azimuth angle tab .

[0171] After obtaining the aforementioned parameter changes, the validity of the current tool contact point is determined based on these changes. If the determination result is invalid, then the feed parameters, such as surface parameters, are adjusted. u Update the data and recalculate the next adjacent tool contact point; if the determination result is valid, save the geometric parameters corresponding to the current tool contact point as valid tool contact point data.

[0172] After the current tool contact is determined to be a valid tool contact, the geometric parameters of the current tool contact are recorded as old data, which are used to calculate the change of the next adjacent tool contact, and the next tool contact is planned based on this.

[0173] Through the above iterative process, continuous tool contact point planning along the blade surface can be achieved. After the tool contact point planning for the current toolpath segment is completed, the feed parameters are adjusted based on the same planning and judgment process to proceed to the planning of the next toolpath segment, until the toolpath planning for all toolpath segments is completed.

[0174] refer to Figure 12 The diagram illustrates a schematic of the blade contact path for a bladed disk. On the curved surface of the bladed disk, starting from the initial blade contact point (… u 0, vStarting at position 0), adjacent tool contacts are generated progressively along the preset feed direction. The tool contact path consists of multiple consecutive effective tool contacts, which are generated within the surface parameter domain from the initial surface parameters. u 0、 v 0 progressively advances to the target surface parameters u 1. v 1. This forms a tool contact path that covers the blade processing area. Figure 12 The diagram illustrates the starting position and the distribution of tool contact points generated step by step along the feed direction, to explain the overall generation process of the tool contact point path within the surface parameter domain.

[0175] refer to Figure 13 The diagram shown is a partially enlarged schematic of the blade contact path of a bladed disk. Specifically, Figure 13 for Figure 12 A magnified view of a local area of ​​the blade cutter contact path in the middle blade disk. Figure 13 As can be seen, in areas where the blade surface of the impeller is significantly curved or exhibits pronounced geometric changes, adjacent knife contacts are more densely distributed along the blade surface to adapt to these geometric variations. Conversely, in areas where the surface curvature is relatively gentle, the spacing between adjacent knife contacts is relatively larger. This magnified schematic diagram visually demonstrates the adaptive adjustment of the knife contact path across different curved surface regions in response to changes in geometric features.

[0176] refer to Figure 14 The diagram illustrates another type of blade contact path for a bladed disk. Multiple spaced-apart contact paths are generated on the blade surface along different feed directions or starting positions. Each contact path consists of multiple continuously distributed contact points along the blade surface, covering different machining areas of the blade. This diagram visually demonstrates that on the same blade surface, contact paths can be generated in groups according to predetermined rules, creating a uniformly distributed contact point coverage effect.

[0177] refer to Figure 15 The diagram shown is an enlarged schematic of the blade contact point path in the trailing edge region of a bladed disk. Specifically, Figure 15 for Figure 14 A magnified view of the trailing edge region of a blade in a mid-disk. In areas with complex geometry or significant curvature variations, such as the trailing edge of the blade, the tool contact paths exhibit a relatively denser distribution to adapt to the geometric changes in the blade's trailing edge. This magnified view of the trailing edge region visually demonstrates the adaptive generation effect of the tool contact paths within these complex areas, thereby ensuring the machining accuracy and surface quality of the blade's trailing edge.

[0178] refer to Figure 16The diagram illustrates a schematic representation of the blade contact path of a blade in a rotary disk after transformation using a ball end mill. When finishing blades using a ball end mill, the positions of the blade contact points on the original blade surface are transformed based on the ball end mill's geometric characteristics, distributing the contact points along the ball end mill's equivalent contact trajectory. The transformed contact path forms multiple continuously distributed trajectories on the blade surface, reflecting the actual contact situation of the ball end mill during blade surface machining.

[0179] refer to Figure 17 and Figure 18 The diagrams shown illustrate various impeller blade cutter contact paths. During impeller blade machining, multiple continuous cutter contact paths are generated along the blade's curved surface. Each path consists of multiple adjacent cutter contacts sequentially, covering the machining area of ​​the impeller blade. Because impeller blades typically exhibit significant spatial torsion and curvature variations, the cutter contact paths on the blade surface display a distribution pattern that gradually bends with the blade's geometry. Figure 17 and Figure 18 It can be seen that the knife contact point path exhibits different distribution patterns on the blade surface to adapt to the spatial torsion and curvature variation characteristics of the impeller blade at different positions.

[0180] refer to Figure 19 and Figure 20 The diagram illustrates a schematic representation of the impeller blade cutter contact path after transformation using a ball end mill. When machining impeller blades with a ball end mill, the cutter contact points on the impeller blade surface are equivalently transformed based on the ball end mill's geometric characteristics, causing the cutter contact points to distribute along the actual contact trajectory of the ball end mill. The transformed cutter contact path forms multiple continuous trajectories on the impeller blade surface, reflecting the actual contact situation of the ball end mill during impeller blade machining. This schematic diagram demonstrates the adaptability of the proposed method to impeller blade cutter contact path generation under different cutter configurations.

[0181] This disclosure, during the tool contact point generation process, uses threshold and tolerance-based judgments to assess changes in distance, orientation, and tool axis oscillation between adjacent tool contacts. Only when the parameter changes are within a preset reasonable range is the current tool contact considered valid. This avoids the problem of repeated generation and rollback of numerous invalid tool contacts due to fixed step sizes or single judgment conditions in related technologies. This method reduces unnecessary iterations in toolpath planning, lowers redundant computational overhead, and prevents a significant decrease in toolpath generation efficiency as surface geometric complexity increases.

[0182] Furthermore, this disclosure no longer uses a single evaluation index to judge the effectiveness of tool contacts. Instead, it uses multiple aspects, such as changes in tool feed and tool oscillation, to jointly determine the geometric changes between adjacent tool contacts. In areas where the surface changes gently or the direction changes are stable, the constraints are relaxed accordingly based on the judgment results to reduce the number of tool contacts. In areas where the surface changes drastically or the direction changes frequently, the constraints are tightened accordingly based on the judgment results to increase the density of tool contacts. This achieves stable control over the density of tool contact generation while ensuring machining accuracy and surface quality, avoiding excessively dense or sparse tool contacts.

[0183] Furthermore, the validity determination of the tool contact points and the adjustment of the feed step size in this disclosure are both set based on the parameter changes between adjacent tool contact points. Each evaluation index participates in the tool contact point generation process as an independent judgment condition and can be activated according to the structural characteristics of the surface model to be processed. When dealing with models with periodic rotational characteristics, such as impellers and impeller disks, evaluation indices related to the rotational direction, such as the azimuth angle threshold, can be introduced to constrain the changes in the toolpath in the periodic direction, thereby ensuring the consistency of the toolpath in the rotational direction. When dealing with ordinary freeform surfaces or models without rotational characteristics, the aforementioned evaluation indices related to the rotational direction are not introduced. The tool contact points can still be generated and screened based on the judgment conditions of the remaining parameter changes. The adjustment rules of the feed step size remain unchanged, the tool contact point generation process does not change, and the generation density of tool contact points can be effectively controlled. Therefore, the method of this disclosure can be applied to different types of surface models, achieving adaptation only through the selection and combination of evaluation indices, without the need to redesign the tool contact point generation process for different model types.

[0184] Furthermore, in this exemplary embodiment, a toolpath planning device for blade finishing is also provided. (Reference) Figure 21 As shown, the blade finishing toolpath planning device 2100 may include a blade surface acquisition module 2110, an evaluation index calculation module 2120, and a machining path determination module 2130, wherein: The blade surface acquisition module 2110 is used to acquire the parametric surface model of the blade to be processed; The evaluation index calculation module 2120 is used to calculate the effective tool contact point evaluation index of the blade to be processed based on the parametric surface model; wherein, the effective tool contact point evaluation index includes at least one of the following: the distance threshold between adjacent tool contact points, the normal vector angle threshold, and the azimuth angle threshold. The machining path determination module 2130 is used to determine the effective tool contact points in the feed direction of the blade to be processed according to the effective tool contact point evaluation index, and generate the blade tool contact point path based on the effective tool contact points.

[0185] The specific details of each module in the aforementioned blade finishing toolpath planning device have been described in detail in the corresponding blade finishing toolpath planning method, so they will not be repeated here.

[0186] Exemplary embodiments of this disclosure also provide a computer-readable storage medium having a program product stored thereon capable of implementing the methods described above in this specification. In some possible embodiments, various aspects of this disclosure may also be implemented as a program product including program code that, when run on an electronic device, causes the electronic device to perform the steps described in the "Exemplary Methods" section of this specification according to the various exemplary embodiments of this disclosure. This program product may be a portable compact disc read-only memory (CD-ROM) including program code and may run on an electronic device, such as a personal computer. However, the program product of this disclosure is not limited thereto; in this disclosure, the readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.

[0187] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0188] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting programs for use by or in conjunction with an instruction execution system, apparatus, or device.

[0189] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0190] Program code for performing the operations of this disclosure can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C#, and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0191] Exemplary embodiments of this disclosure also provide an electronic device capable of implementing the above-described method. Referring below... Figure 22 To describe an electronic device 2200 according to such an exemplary embodiment of the present disclosure. Figure 22 The electronic device 2200 shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments disclosed herein.

[0192] like Figure 22 As shown, the electronic device 2200 can be represented as a general-purpose computing device. The components of the electronic device 2200 may include, but are not limited to: at least one processing unit 2210, at least one storage unit 2220, a bus 2230 connecting different system components (including storage unit 2220 and processing unit 2210), and a display unit 2240.

[0193] Storage unit 2220 stores program code that can be executed by processing unit 2210, causing processing unit 2210 to perform the steps described in the "Exemplary Methods" section of this specification according to various exemplary embodiments of this disclosure. For example, processing unit 2210 can perform... Figure 2 The methods and steps in the text.

[0194] Storage unit 2220 may include readable media in the form of volatile storage units, such as random access memory (RAM) 2221 and / or cache memory (Cache) 2222, and may further include read-only memory (ROM) 2223.

[0195] Storage unit 2220 may also include a program / utility 2224 having a set (at least one) program module 2225, such program module 2225 including but not limited to: operating system, one or more application programs, other program modules and program data, each or some combination of these examples may include an implementation of a network environment.

[0196] Bus 2230 can represent one or more of several types of bus structures, including memory cell bus or memory cell controller, peripheral bus, graphics acceleration port, processing unit, or local bus using any of the multiple bus structures.

[0197] Electronic device 2200 can also communicate with one or more external devices 2270 (e.g., keyboard, pointing device, Bluetooth device, etc.), and with one or more devices that enable a user to interact with electronic device 2200, and / or with any device that enables electronic device 2200 to communicate with one or more other computing devices (e.g., router, modem, etc.). This communication can be performed via input / output (I / O) interface 2250. Furthermore, electronic device 2200 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 2260. As shown, network adapter 2260 communicates with other modules of electronic device 2200 via bus 2230. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 2000, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID (Redundant Array of Independent Disks) systems, tape drives, and data backup storage systems.

[0198] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, terminal device, or network device, etc.) to execute the method according to the exemplary embodiments of this disclosure.

[0199] Furthermore, the above figures are merely illustrative representations of the processes included in the methods according to exemplary embodiments of this disclosure, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0200] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of this disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0201] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the claims.

[0202] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A tool path planning method for blade finishing, characterized in that, include: Obtain the parametric surface model of the blade to be processed; Based on the parametric surface model, the effective tool contact point evaluation index of the blade to be processed is calculated; wherein, the effective tool contact point evaluation index includes at least one of the following: distance threshold between adjacent tool contacts, normal vector angle threshold, and azimuth angle threshold; The effective tool contact points in the feed direction of the blade to be processed are determined according to the effective tool contact point evaluation index, and the blade tool contact point path is generated based on the effective tool contact points.

2. The blade finishing tool path planning method according to claim 1, characterized in that, The calculation of the effective tool contact point evaluation index of the blade to be processed based on the parametric surface model includes: Based on the parametric surface model, the geometric distribution characteristics of the blade to be processed are determined, and the effective tool contact point evaluation index of the blade to be processed is calculated based on the geometric distribution characteristics. The geometric distribution features include at least one of spatial position distribution, normal vector distribution, and azimuth distribution; the effective tool contact evaluation index includes at least one of the following: a distance threshold between adjacent tool contacts determined based on the spatial position distribution of the parametric surface model in the feed direction of the blade to be processed, a normal vector angle threshold between adjacent tool contacts determined based on the normal vector distribution on the parametric surface model, and an azimuth angle threshold between adjacent tool contacts determined based on the azimuth distribution of the parametric surface model in a preset reference plane.

3. The blade finishing tool path planning method according to claim 2, characterized in that, Determining the distance threshold between adjacent blade contacts includes: Based on the parametric surface model, a surface section line representing the blade processing range is extracted in the feed direction of the blade to be processed; Calculate the length parameter of the curved section line within the blade processing range, and determine the distance threshold between adjacent tool contact points based on the length parameter and the preset curved section point density.

4. The blade finishing tool path planning method according to claim 2, characterized in that, Determining the threshold of the normal vector angle between adjacent blade contacts includes: Determine the normal vector distribution on the parameterized surface model, and determine the normal vector angle subdivision parameters based on the normal vector distribution; Based on the normal vector angle subdivision parameters and combined with the preset first angle mapping relationship, the threshold of the normal vector angle between adjacent blade contacts is determined.

5. The blade finishing tool path planning method according to claim 2, characterized in that, Determining the azimuth angle threshold between adjacent blade contacts includes: The parametric surface model is mapped to the preset reference plane to obtain the orientation distribution of the parametric surface model in the preset reference plane, and the azimuth subdivision parameters are determined based on the orientation distribution. Based on the azimuth subdivision parameters and combined with the preset second angle mapping relationship, the azimuth angle threshold between adjacent blade contacts is determined.

6. The blade finishing tool path planning method according to claim 1, characterized in that, The step of determining the effective tool contact points in the feed direction of the blade to be processed according to the effective tool contact point evaluation index, and generating the blade tool contact point path based on the effective tool contact points, includes: The current tool contact point is determined in the feed direction of the blade to be processed, and the geometric parameters corresponding to the current tool contact point are calculated based on the parameterized surface model. Based on the geometric parameters of the current cutter contact and the determined geometric parameters of the previous cutter contact, calculate the parameter change corresponding to the effective cutter contact evaluation index; The parameter change is compared with the effective contact evaluation index to determine whether the current contact is an effective contact. If the current tool contact point is determined to be a valid tool contact point, iterative updates are performed along the feed direction of the blade to be processed to generate the blade tool contact point path.

7. The blade finishing tool path planning method according to claim 6, characterized in that, The geometric parameters include at least one of spatial position, normal vector, and azimuth angle; The calculation of the geometric parameters corresponding to the current tool contact point based on the parametric surface model includes: At the start of tool contact path planning, initialize the feed parameters and the geometric parameters of the previous tool contact; The current feed parameters are updated based on the feed parameters corresponding to the previous cutter contact and the preset feed step size. Substitute the current feed parameters into the parameterized surface model to determine the surface parameter position corresponding to the current tool contact point, and calculate the spatial position of the current tool contact point based on the surface parameter position; and / or Based on the surface normal vector function defined in the parameterized surface model, the normal vector of the current tool contact point is obtained at the surface parameter position corresponding to the current tool contact point; and / or Calculate the azimuth angle corresponding to the current blade contact point based on its spatial position.

8. The blade finishing tool path planning method according to claim 7, characterized in that, The calculation of parameter changes corresponding to the effective tool contact evaluation index based on the geometric parameters of the current tool contact point and the determined geometric parameters of the previous tool contact point includes: Based on the geometric parameters of the current cutter contact and the geometric parameters of the previous cutter contact, calculate at least one of the following parameter changes between the current cutter contact and the previous cutter contact: the change in distance, the change in the normal vector angle, and the change in the azimuth angle. These parameters are used as the parameter changes corresponding to the effective cutter contact evaluation index.

9. The blade finishing tool path planning method according to claim 6, characterized in that, The step of comparing the parameter change with the effective contact point evaluation index to determine whether the current contact point is an effective contact point includes: Based on the effective knife contact evaluation index, at least one tolerance is determined among the distance tolerance, normal vector angle tolerance, and azimuth angle tolerance between the current knife contact and the previous knife contact. Based on the effective knife contact evaluation index and the corresponding tolerance, a reference range for the parameter variation is constructed; The parameter change is compared with the reference range. If the parameter change falls within the reference range, the current tool contact is determined to be a valid tool contact.

10. The blade finishing tool path planning method according to claim 6, characterized in that, The step of iteratively updating along the feed direction of the blade to be processed, when the current blade contact point is determined to be a valid blade contact point, to generate the blade blade contact point path, includes: If the current cutter contact is determined to be a valid cutter contact, the current cutter contact is updated to the new previous cutter contact; Based on the updated previous cutter contact point, a new current cutter contact point is determined along the feed direction of the blade to be processed, and the parameter change calculation and cutter contact point validity determination steps are repeated until the blade cutter contact point path is generated.

Images