A turning system and method for complex parts

Abstract

The application provides a turning machining system and method for complex parts, a machining surface relationship diagram of a target cutting machining area is constructed through a three-dimensional CAD model of a complex part to be turned, a feature extraction surface containing a closed inner ring is selected from the machining surface relationship diagram, and a candidate feature surface set of the target cutting machining area is determined, the candidate feature surface set is compared with a preset non-machining structure surface set, if there is a common surface between the two, the machining surface belonging to the non-machining structure surface set is removed, and the topological connection relationship of the target cutting machining area is reconstructed, the machining feature type of the target cutting machining area is determined through the reconstructed topological connection relationship of the target cutting machining area, the confidence turning tool path is generated according to the machining feature type, and the complex part to be turned is turned through the confidence turning tool path. The technical scheme provided by the application can turn the complex part through the effective tool path under the influence of the non-machining structure.

Description

Technical Field

[0001] This application relates to the field of turning technology, and more specifically, to a turning system and method for complex parts. Background Technology

[0002] Turning is a material removal process. Its core is the cooperation between the workpiece rotation as the main motion and the tool feed motion to achieve the forming of the surface of a rotating body. As the most basic and widely used machining method in the field of mechanical manufacturing, turning can efficiently handle features such as internal and external cylindrical surfaces, conical surfaces, end faces, threads, and shaped surfaces. In modern manufacturing systems, ordinary lathes are gradually being replaced by turning centers equipped with CNC systems and power turrets. They can complete composite machining such as turning, milling, drilling, and tapping in one setup, which significantly improves geometric accuracy and production efficiency.

[0003] In conventional turning processes, excess material is removed by utilizing the workpiece's rotational main motion and the tool's linear feed motion. The workpiece is clamped in a spindle chuck and rotates at a set speed, while the cutting tool is fixed on a tool post and makes precise feed motions along the longitudinal (axial) or transverse (radial) direction according to the machining requirements to achieve the machining of features such as external diameters, end faces, threads, and tapered surfaces. However, in turning processes involving complex parts, these parts not only contain areas of material that need to be removed by turning but also a large number of pre-existing non-machinable structures. These non-machinable structural surfaces are different from the actual cutting surfaces. The cutting region is highly coupled geometrically (e.g., coplanar, adjacent) and topologically (e.g., closed inner loops sharing a boundary). Traditional algorithms often rely solely on geometric topology for feature extraction, which can easily lead to the misidentification of adjacent non-machined surfaces as part of the cutting region. Alternatively, the presence of non-machined surfaces can cause the cutting region, which should be continuous, to be incorrectly segmented into multiple discrete and independent features, resulting in low confidence in the generated tool path and the inability to complete the full surface machining. Therefore, how to perform turning machining on complex parts with an effective tool path under the influence of non-machined structures has become a challenge for the industry. Summary of the Invention

[0004] This application provides a turning system and method for complex parts, which can turn complex parts through an effective tool path without the influence of non-machining structures.

[0005] In a first aspect, this application provides a turning method for complex parts, comprising the following steps:

[0006] A machining surface relationship diagram is constructed based on a 3D CAD model of a complex part to be machined, which describes the topology of the target cutting area.

[0007] From the machining surface relationship diagram, feature extraction surfaces containing closed inner rings are selected, and all machining surfaces adjacent to the closed inner rings are searched using the closed inner rings as seed contours to form a set of candidate feature surfaces for the target cutting machining area.

[0008] The candidate feature surface set is compared with the preset non-machined structure surface set. If there is a common surface between the two, the machined surface belonging to the non-machined structure surface set is removed from the candidate feature surface set. The topological connection relationship of the target cutting machining area is reconstructed based on multiple remaining machined surfaces that are spatially coplanar and adjacent to the same non-machined structure surface.

[0009] The machining feature type of the target cutting machining region is determined by the topological connection relationship of the reconstructed target cutting machining region, and then a confidence turning tool trajectory of the complex part is generated according to the machining feature type.

[0010] The complex parts to be machined are turned using the confidence turning tool path.

[0011] In some embodiments, constructing a machining surface relationship diagram based on a 3D CAD model of a complex part to be machined to describe the topology of the target cutting area specifically includes:

[0012] The three-dimensional CAD model of a complex part to be turned is decomposed into a surface element and its geometric attributes are extracted to obtain the set of machining surfaces and the geometric constraint information of each machining surface.

[0013] Based on the set of machining surfaces and the geometric constraint information of each machining surface, establish the adjacency, coplanarity, and intersection topological relationships between machining surfaces;

[0014] Based on the topological relationships between the machining surfaces, a machining surface relationship diagram is constructed to describe the topological structure of the target cutting machining area.

[0015] In some embodiments, selecting feature extraction surfaces containing closed inner loops from the processing surface relationship diagram specifically includes:

[0016] Traverse each machining surface in the machining surface relationship diagram and extract the boundary ring information of each machining surface, and identify the machining surface with a closed inner ring based on the boundary ring topological closure determination rule;

[0017] The processing surface with the closed inner ring is matched and verified with the preset processing surface attribute threshold, and the processing surface that does not meet the feature extraction conditions is removed.

[0018] The machined surface with a closed inner ring that passes the verification is identified as the feature extraction surface of the target cutting machining area.

[0019] In some embodiments, searching for all machining surfaces adjacent to the closed inner ring as a seed contour to form a candidate feature surface set for the target cutting machining region specifically includes:

[0020] Using the closed inner ring in the feature extraction surface as the seed contour, the processing surfaces adjacent to the closed inner ring are obtained by traversing according to the topological adjacency relationship in the processing surface relationship graph.

[0021] The adjacent machining surfaces are included in a temporary extended surface set, and the adjacent machining surfaces are iteratively searched based on the machining surfaces in the temporary extended surface set.

[0022] All adjacent machining surfaces obtained from iterative searches are combined with the feature extraction surfaces to form a set of candidate feature surfaces for the target cutting machining region.

[0023] In some embodiments, comparing the candidate feature surface set with a preset set of unprocessed structural surfaces, and removing the processed surfaces belonging to the set of unprocessed structural surfaces from the candidate feature surface set specifically includes:

[0024] Extract the geometric feature parameters and surface identification information of each processed surface in the candidate feature surface set, and at the same time retrieve the preset non-processed structural surface set and the corresponding parameters of each surface therein;

[0025] The geometric feature parameters and surface identification information of the candidate feature surface set are compared one by one with the corresponding parameters of the non-processed structure surface set to determine whether there is a common surface between them.

[0026] If a common surface is found during the comparison, the processed surfaces that belong to the non-processed structure surface set in the candidate feature surface set are selected and removed from the candidate feature surface set.

[0027] In some embodiments, reconstructing the topological connectivity of the target cutting region based on multiple spatially coplanar and adjacent unmachined structural surfaces specifically includes:

[0028] Extract the spatial location parameters and adjacency information of the remaining machined surfaces after removing the non-machined structural surfaces, and filter out multiple remaining machined surfaces that are spatially coplanar and adjacent to the same non-machined structural surface;

[0029] Multiple remaining processed surfaces selected from the screening are subjected to coplanar fusion processing to generate a unified processed surface after fusion.

[0030] Based on the unified machining surface after fusion, the remaining unfused machining surfaces, and their original topological relationships, the topological connection relationship of the target cutting machining area is reconstructed.

[0031] In some embodiments, determining the machining feature type of the target cutting region by the topological connectivity of the reconstructed target cutting region specifically includes:

[0032] Extract the topological connectivity of the reconstructed target cutting region and the geometric attribute information of the corresponding machining surface to construct a machining feature description vector;

[0033] The machining feature description vector is matched with the feature templates in the preset turning machining feature library to obtain the matching degree parameter;

[0034] The machining feature type of the target cutting area is determined based on the matching degree parameter.

[0035] Secondly, this application provides a turning system for complex parts, used to perform a turning method for complex parts, the system comprising:

[0036] The module is used to construct a machining surface relationship diagram that describes the topology of the target cutting area based on the 3D CAD model of the complex part to be machined;

[0037] The processing module is used to filter out feature extraction surfaces containing closed inner rings from the machining surface relationship diagram, and use the closed inner ring as a seed contour to search for all machining surfaces adjacent to the closed inner ring, forming a set of candidate feature surfaces for the target cutting machining area;

[0038] The processing module is further configured to compare the candidate feature surface set with the preset non-machining structure surface set. If the two have a common surface, the machining surface belonging to the non-machining structure surface set is removed from the candidate feature surface set, and the topological connection relationship of the target cutting machining area is reconstructed based on multiple remaining machining surfaces that are spatially coplanar and adjacent to the same non-machining structure surface.

[0039] The processing module is also used to determine the machining feature type of the target cutting machining area through the topological connection relationship of the reconstructed target cutting machining area, and then generate a confidence turning tool trajectory for the complex part based on the machining feature type;

[0040] The execution module is used to turn complex parts to be machined by means of the confidence turning tool path.

[0041] Thirdly, this application provides a computer device including a memory and a processor, the memory storing code, and the processor being configured to acquire the code and execute the above-described turning method for complex parts.

[0042] Fourthly, this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described turning method for complex parts.

[0043] The technical solutions provided by the embodiments disclosed in this application have the following beneficial effects:

[0044] The turning system and method for complex parts provided in this application firstly construct a machining surface relationship diagram describing the topological structure of the target cutting machining area based on a 3D CAD model of the complex part to be turned. Secondly, feature extraction surfaces containing closed inner rings are selected from the machining surface relationship diagram, and all machining surfaces adjacent to the closed inner rings are searched using the closed inner rings as seed contours to form a candidate feature surface set for the target cutting machining area. Further, the candidate feature surface set is compared with a preset set of non-machining structural surfaces. If there is a common surface between the two, the machining surfaces belonging to the set of non-machining structural surfaces are removed from the candidate feature surface set, and the topological connection relationship of the target cutting machining area is reconstructed based on multiple remaining machining surfaces that are spatially coplanar and adjacent to the same non-machining structural surface. Then, the machining feature type of the target cutting machining area is determined by the reconstructed topological connection relationship of the target cutting machining area, and a confidence turning tool trajectory for the complex part is generated according to the machining feature type. Finally, the complex part to be turned is turned using the confidence turning tool trajectory.

[0045] Therefore, this application demonstrates that it can perform turning machining on complex parts using effective tool trajectories even without the influence of non-machining structures. Firstly, by constructing a machining surface relationship diagram based on a 3D CAD model, the spatial and topological relationships between the machining surfaces of the part can be structurally expressed, providing a reliable data foundation for subsequent region identification. Secondly, based on feature extraction surfaces containing closed inner loops, a set of candidate feature surfaces is formed by searching for adjacent machining surfaces in the machining surface relationship diagram, which can locate potential machining areas and avoid the errors and inefficiencies caused by manual selection. Furthermore, by comparing the candidate feature surfaces with the non-machining structure surfaces and eliminating common surfaces, and then reconstructing the topological connection relationships of the remaining machining surfaces that are coplanar and adjacent to the same non-machining surface, invalid machining surfaces can be eliminated, and scattered machining surfaces can be removed. This approach avoids interference from segmented surfaces, preventing the problem of low confidence in the generated tool path caused by high geometric and topological coupling between non-machining structural surfaces and the actual cutting area. It ensures geometric continuity and clear topology in the machining area, better reflecting the actual machining process. Then, based on the reconstructed topological relationships, the machining feature type is determined, enabling automatic identification of the machining area from geometric structure to process features, providing a clear basis for subsequent trajectory planning. Finally, a confident turning tool path is generated according to the machining feature type, and cutting is completed, ensuring a stable and reliable trajectory. Ultimately, this achieves automated, high-precision CNC turning of complex parts. In summary, the technical solution provided in this application can perform turning of complex parts using an effective tool path under the influence of non-machining structures. Attached Figure Description

[0046] Figure 1 This is an exemplary flowchart of a turning method for complex parts according to some embodiments of this application;

[0047] Figure 2 This is an exemplary flowchart illustrating the determination of feature extraction surfaces according to some embodiments of this application;

[0048] Figure 3 This is a schematic diagram of the structure of a turning system for complex parts according to some embodiments of this application;

[0049] Figure 4 This is a schematic diagram of the structure of a computer device for implementing a turning process for complex parts, according to some embodiments of this application. Detailed Implementation

[0050] To better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0051] refer to Figure 1 This figure is an exemplary flowchart of a turning method for complex parts according to some embodiments of this application, which mainly includes the following steps:

[0052] In step S101, a machining surface relationship diagram is constructed based on the three-dimensional CAD model of the complex part to be machined, which describes the topology of the target cutting machining area.

[0053] In some embodiments, constructing a machining surface relationship diagram describing the topology of the target cutting machining area based on a 3D CAD model of a complex part to be machined can be achieved using the following steps:

[0054] The three-dimensional CAD model of a complex part to be turned is decomposed into a surface element and its geometric attributes are extracted to obtain the set of machining surfaces and the geometric constraint information of each machining surface.

[0055] Based on the set of machining surfaces and the geometric constraint information of each machining surface, establish the adjacency, coplanarity, and intersection topological relationships between machining surfaces;

[0056] Based on the topological relationships between the machining surfaces, a machining surface relationship diagram is constructed to describe the topological structure of the target cutting machining area.

[0057] In specific implementation, firstly, the boundary representation parsing interface of the CAD boundary representation model is used to directly read the topological and geometric surface data of the 3D CAD model of the complex part to be machined, thereby obtaining the set of machining surfaces of the complex part to be machined. The set of machining surfaces refers to the set of all geometric surface units on the solid surface of the complex part to be machined. At the same time, based on the geometric query function of the CAD kernel, the inherent attributes of each machining surface in the set of machining surfaces, including normal vector, boundary curve type, and boundary closure state, are extracted to obtain the geometric constraint information of each machining surface. The geometric constraint information refers to the set of geometric parameters used to uniquely determine the spatial shape and positional relationship of the machining surface. The CAD boundary representation model refers to the representation method in 3D CAD modeling that uses the solid boundary as the core to structurally describe the geometric and topological information of the part. By decomposing the solid model into basic topological elements such as vertices, edges, faces, loops, and volumes, and clearly recording the constraint relationships such as subordination, connection, enclosure, and adjacency between each element, and combining geometric definitions such as curves and surfaces, the shape and spatial structure of the solid model are accurately described. This can provide complete and directly callable geometric and topological data for subsequent machining surface extraction, topological relationship query, and boundary loop identification. Data support is provided; then, using the set of processing surfaces and geometric constraint information as input, the adjacency relationship is determined by detecting whether the processing surfaces share a common boundary curve, the coplanar relationship is determined by comparing whether the normal vectors are consistent and whether there are common overlapping line segments, and the intersection relationship is determined by determining whether there are intersecting curves, so as to establish the adjacency, coplanar, and intersection topological relationships between processing surfaces. The topological relationship refers to the set of relationships describing the spatial connection and intersection states between each processing surface; finally, using the topological relationship as input, an undirected graph construction method is used to map each processing surface as a node, and the relationships between each pair of processing surfaces are defined. The adjacency, coplanarity, or intersection relationships are mapped as edges to construct a machining surface relationship diagram that describes the topological structure of the target cutting machining region. The target cutting machining region refers to the continuous geometric surface that needs to be removed by the turning tool, which is divided from the three-dimensional model of the complex part to be turned based on the topological relationship, geometric constraints, and turning process requirements. This region is composed of machining surfaces that have topological relationships such as adjacency, coplanarity, or intersection with each other. It has a clear boundary contour and spatial shape and is the direct object and scope carrier for subsequent machining feature recognition, tool trajectory planning, and actual cutting execution.

[0058] It should be noted that the machining surface relationship diagram in this application refers to a data structure that uses a node-edge structure to represent the spatial connection and distribution of each machining surface within the target cutting machining area. Constructing the machining surface relationship diagram can transform the originally discrete and disordered machining surface units of the 3D CAD model into a structured overall expression through topological association. This clearly and quantitatively describes the spatial attachment and connection forms such as adjacency, coplanarity, and intersection between each machining surface within the target cutting machining area. It provides a unified and stable topological data foundation for subsequent closed inner loop identification, feature surface search, and machining area reconstruction, avoiding misjudgment of the machining area due to the complexity of the part shape and the large number of curved surfaces.

[0059] In step S102, feature extraction surfaces containing closed inner rings are selected from the machining surface relationship diagram, and all machining surfaces adjacent to the closed inner rings are searched using the closed inner rings as seed contours to form a set of candidate feature surfaces for the target cutting machining area.

[0060] In some embodiments, reference Figure 2 As shown, this figure is an exemplary flowchart illustrating the determination of feature extraction surfaces according to some embodiments of this application. In this embodiment, the selection of feature extraction surfaces containing closed inner loops from the processing surface relationship graph can be achieved through the following steps:

[0061] In step S1021, each machining surface in the machining surface relationship diagram is traversed and the boundary ring information of each machining surface is extracted. Based on the boundary ring topology closure determination rule, the machining surface with a closed inner ring is identified.

[0062] In step S1022, the machining surface with the closed inner ring is matched and verified with the preset machining surface attribute threshold, and machining surfaces that do not meet the feature extraction conditions are removed.

[0063] In step S1023, the machining surface with a closed inner ring that has passed the verification is determined as the feature extraction surface of the target cutting machining area.

[0064] In specific implementation, firstly, each machining surface is traversed sequentially according to the node order recorded in the machining surface relationship diagram. By calling the boundary query interface of the CAD boundary representation model, the outer boundary curve and inner boundary curve of each machining surface are extracted respectively. Then, all curve segments of each boundary curve are connected end to end in sequence to determine whether they form a closed loop without breaks, openings, and overlapping endpoints. This identifies machining surfaces with closed inner loops. Here, a closed inner loop refers to a boundary curve that is inside the machining surface, separated from the outer boundary, and can form a continuous closed loop. Then, the identified machining surfaces with closed inner loops are used as verification objects. Their inherent attributes such as surface type, curvature range, number of boundaries, and spatial orientation are compared with the machining surface attribute thresholds set in advance according to the turning machining requirements. Machining surfaces whose attribute parameters do not fall within the range of the machining surface attribute thresholds are eliminated. Here, the machining surface attribute thresholds refer to the geometric and topological attribute limits set in advance to filter effective feature surfaces. The specific limits can be set according to actual needs and are not limited here. Finally, the machining surfaces that have been compared and verified and have closed inner loops are determined as the feature extraction surfaces of the target cutting machining area.

[0065] It should be noted that, in this application, the feature extraction surface refers to the machining surface used to guide the search of adjacent machining surfaces. By determining the feature extraction surface, the reference machining surface containing a closed inner ring and having typical turning feature marks can be accurately located among the many machining surfaces of a complex part. This serves as a stable starting point for subsequent region growth and feature recognition, avoiding the confusion in region division, misidentification of features, or computational redundancy caused by blindly searching from all machining surfaces.

[0066] In some embodiments, searching for all machining surfaces adjacent to the closed inner ring as a seed contour to form a set of candidate feature surfaces for the target cutting region can be achieved using the following steps:

[0067] Using the closed inner ring in the feature extraction surface as the seed contour, the processing surfaces adjacent to the closed inner ring are obtained by traversing according to the topological adjacency relationship in the processing surface relationship graph.

[0068] The adjacent machining surfaces are included in a temporary extended surface set, and the adjacent machining surfaces are iteratively searched based on the machining surfaces in the temporary extended surface set.

[0069] All adjacent machining surfaces obtained from iterative searches are combined with the feature extraction surfaces to form a set of candidate feature surfaces for the target cutting machining region.

[0070] In specific implementation, firstly, using the closed inner ring in the feature extraction surface as the seed contour and the topological adjacency relationship in the processing surface relationship graph as the data basis, the processing surface nodes that share a common edge or common vertex with the boundary of the closed inner ring in the processing surface relationship graph are traversed to query and obtain the adjacent processing surfaces that are directly connected to the closed inner ring. The adjacent processing surfaces refer to the processing surfaces that share a common boundary curve with the boundary of the closed inner ring in the processing surface relationship graph and are directly connected topologically. Then, the above-mentioned adjacent processing surfaces are added to a temporary extended surface set, and each processing surface in the temporary extended surface set is used as the current reference for processing. In the machining surface relationship graph, continue to query machining surfaces that have topological adjacency relationships with each reference machining surface but have not yet been included. Add the newly queried machining surfaces to the temporary extended surface set in turn and repeat the above adjacency retrieval operation to complete the region-growing iterative search. The temporary extended surface set refers to the intermediate data set used to temporarily store the retrieved adjacent machining surfaces and provide a reference for the next layer of retrieval during the iterative search process. Finally, merge all machining surfaces in the temporary extended surface set after the iterative search with the initial feature extraction surface to form a candidate feature surface set containing all relevant machining units within the target cutting machining area.

[0071] It should be noted that, in this application, the candidate feature surface set refers to the initial processing surface set composed of the feature extraction surface and all adjacent processing surfaces obtained by iterative retrieval. The purpose of determining the candidate feature surface set is to organically combine discrete and scattered processing surfaces into a continuous and complete processing region by starting from the closed inner loop of the feature extraction surface and using topological adjacency relationships. This avoids the problems of large computational load, blurred feature boundaries, and easy mixing of irrelevant surfaces caused by directly identifying the processing surfaces of the entire model. Its role is to provide a well-defined and structurally continuous initial processing surface set for subsequent non-processing structure surface elimination and topological connection relationship reconstruction, ensuring the integrity of the target cutting processing region and improving the reliability and efficiency of processing feature recognition and trajectory planning.

[0072] In step S103, the candidate feature surface set is compared with the preset non-machining structure surface set. If there is a common surface between the two, the machining surface belonging to the non-machining structure surface set is removed from the candidate feature surface set, and the topological connection relationship of the target cutting machining area is reconstructed based on multiple remaining machining surfaces that are spatially coplanar and adjacent to the same non-machining structure surface.

[0073] In some embodiments, comparing the candidate feature surface set with a preset set of unprocessed structural surfaces, and removing the processed surfaces belonging to the set of unprocessed structural surfaces from the candidate feature surface set can be achieved by the following steps:

[0074] Extract the geometric feature parameters and surface identification information of each processed surface in the candidate feature surface set, and at the same time retrieve the preset non-processed structural surface set and the corresponding parameters of each surface therein;

[0075] The geometric feature parameters and surface identification information of the candidate feature surface set are compared one by one with the corresponding parameters of the non-processed structure surface set to determine whether there is a common surface between them.

[0076] If a common surface is found during the comparison, the processed surfaces that belong to the non-processed structure surface set in the candidate feature surface set are selected and removed from the candidate feature surface set.

[0077] In specific implementation, firstly, for each machined surface in the candidate feature surface set, its unique surface identifier, spatial position, normal vector, boundary curve set, and surface type information are extracted through the attribute query interface of the CAD boundary representation model, forming the geometric feature parameters and surface identifier information corresponding to each machined surface. Simultaneously, the set of non-machined structural surfaces composed of the non-cutting parts of the part and their corresponding parameters are retrieved from the pre-stored process configuration data. The geometric feature parameters refer to the set of parameters used to uniquely describe the geometric shape and spatial position of the machined surface, and the surface identifier information refers to the unique index information in the CAD model used to distinguish different surfaces. The set of non-machined structural surfaces refers to the set of part structural surfaces pre-defined according to the turning process that do not require cutting. Then, using the candidate feature surface set and the set of non-machined structural surfaces as processing objects, candidate feature surfaces are selected sequentially. For each individual machined surface in the set, its unique surface identifier is precisely matched with the surface identifiers of each surface in the set of non-machined structural surfaces. Simultaneously, the geometric feature parameters of the machined surface, including its spatial position, normal vector, boundary curve composition, and surface type, are compared item by item with the geometric feature parameters of the corresponding surface in the set of non-machined structural surfaces. Through the dual judgment conditions of surface identifier consistency and complete geometric feature overlap, it is confirmed whether the same machined surface exists in the candidate feature surface set and the set of non-machined structural surfaces, thereby accurately determining whether there is a common surface between them. The common surface refers to the same machined surface that belongs to both the candidate feature surface set and the set of non-machined structural surfaces. Finally, when a common surface is determined to exist, based on the successfully matched surface identifier information and geometric feature parameters, the machined surface belonging to the set of non-machined structural surfaces is located in the candidate feature surface set and removed, resulting in the remaining set of machined surfaces after removing the non-machined surfaces.

[0078] It should be noted that in this embodiment, the remaining machining surface set refers to the total number of machining surfaces that are actually needed to participate in turning machining feature recognition and subsequent topology reconstruction after removing machining surfaces that belong to the non-machining structure surface set from the candidate feature surface set. This set only includes valid machining surfaces that are related to the target cutting machining area and require material removal, providing a clean and accurate geometric and topological data foundation for subsequent topology connection reconstruction and machining feature type determination.

[0079] In some embodiments, reconstructing the topological connectivity of the target cutting region based on multiple spatially coplanar and adjacent unmachined structural surfaces can be achieved using the following steps:

[0080] Extract the spatial location parameters and adjacency information of the remaining machined surfaces after removing the non-machined structural surfaces, and filter out multiple remaining machined surfaces that are spatially coplanar and adjacent to the same non-machined structural surface;

[0081] Multiple remaining processed surfaces selected from the screening are subjected to coplanar fusion processing to generate a unified processed surface after fusion.

[0082] Based on the unified machining surface after fusion, the remaining unfused machining surfaces, and their original topological relationships, the topological connection relationship of the target cutting machining area is reconstructed.

[0083] In specific implementation, firstly, based on the set of remaining processed surfaces after removing non-processed structural surfaces, the spatial position parameters of each remaining processed surface, including its normal vector, spatial orientation, boundary curve coordinates, and adjacent surface index, are obtained through the geometric query function in the CAD boundary representation model. Then, the dependency relationships between each remaining processed surface and its adjacent non-processed structural surfaces are obtained through a topology query interface, forming adjacency information. The spatial position parameters refer to geometric data used to uniquely determine the spatial orientation, geometric shape, and distribution location of the processed surface. The adjacency information refers to the topological relationship data of whether each remaining processed surface shares a boundary with its surrounding non-processed structural surfaces and whether they are mutually dependent. The normal vectors of each remaining processed surface are compared for consistency to determine if they are parallel. Simultaneously, the planes on which each processed surface lies are compared to determine if they overlap. Furthermore, it is determined whether these coplanar remaining processed surfaces all share a common boundary with the same non-processed structural surface, thereby filtering out multiple remaining processed surfaces that are spatially coplanar and adjacent to the same non-processed structural surface. Then… For the selected remaining machining surfaces, a coplanar splicing and boundary fusion method is used to remove the internal common boundaries between adjacent machining surfaces, splicing the segmented surfaces into a continuous and uninterrupted single surface to form a unified machining surface after fusion. The unified machining surface refers to a continuous single machining surface formed by fusion of multiple coplanar and adjacent segmented machining surfaces. Finally, the unified machining surface after fusion and the unfused remaining machining surfaces are used as topological units. The original adjacency, dependency, and boundary constraint relationships between each topological unit and its adjacent surfaces before reconstruction are retained. The unified machining surface after fusion is used as a single topological node to replace the multiple segmented machining surfaces before fusion. The original connection relationships between other unfused machining surfaces and surrounding non-machining structural surfaces remain unchanged. At the same time, the existing topological associations between the unfused remaining machining surfaces are maintained. By re-establishing the connection relationships and hierarchical constraints between each topological unit, a continuous, complete, and actual machining topological structure of the target cutting machining area is formed, thereby completing the reconstruction of the topological connection relationship of the target cutting machining area.

[0084] It should be noted that, in this application, the topological connection relationship refers to the structured data describing the adjacency, connection, and constraint relationships between the machining surfaces within the reconstructed target cutting machining area. Determining the topological connection relationship of the target cutting machining area can organize the fused unified machining surface and the unfused remaining machining surfaces into a logically clear and spatially constrained overall structure, accurately reflecting the adjacency, dependence, and boundary constraint states between each machining surface. Its function is to provide a stable and reliable topological foundation for subsequent machining feature type identification, process parameter matching, and tool trajectory planning, avoiding feature misjudgment caused by segmented or scattered surfaces, ensuring that the trajectory generation of the turning machining area is reasonable and reliable, and improving the accuracy and stability of machining feature identification and machining execution for complex parts.

[0085] In step S104, the machining feature type of the target cutting machining area is determined by the topological connection relationship of the reconstructed target cutting machining area, and then the confidence turning tool trajectory of the complex part is generated according to the machining feature type.

[0086] In some embodiments, determining the machining feature type of the target cutting region by the reconstructed topological connectivity of the target cutting region can be achieved through the following steps:

[0087] Extract the topological connectivity of the reconstructed target cutting region and the geometric attribute information of the corresponding machining surface to construct a machining feature description vector;

[0088] The machining feature description vector is matched with the feature templates in the preset turning machining feature library to obtain the matching degree parameter;

[0089] The machining feature type of the target cutting area is determined based on the matching degree parameter.

[0090] In specific implementation, firstly, based on the reconstructed topological connectivity of the target cutting area, the geometric attribute information of each machining surface within the target cutting area is extracted through the geometric query interface of the CAD boundary representation model. This information includes the surface type, normal vector orientation, number of boundaries, inner and outer loop attributes, and the adjacency and coplanarity of the machining surfaces. The aforementioned topological connectivity and geometric attribute information are then arranged according to pre-defined ordered combination rules to construct a machining feature description vector that uniquely represents the geometry and topology of the current cutting area. This machining feature description vector refers to an ordered data set formed by combining topological connectivity and geometric attribute information in a fixed order, used to characterize the structural features of the target cutting area. Then, this machining feature description vector... The feature is compared item by item with various standard feature templates in a pre-established turning feature library based on the turning process. That is, a similarity calculation method is used to calculate the consistency between the machining feature description vector and the corresponding dimension attribute items in each feature template, so as to obtain a matching degree parameter that reflects the degree of similarity between the current feature to be identified and the standard template. The matching degree parameter is an index that characterizes the degree of matching between the machining feature and the standard feature template. The pre-established turning feature library refers to a set of standard feature templates pre-established based on typical turning structures such as outer circle, inner hole, end face, relief groove, and step, which is not limited here. Finally, the feature template with the largest matching degree parameter is selected, and the turning feature category corresponding to the template is determined as the machining feature type of the current target cutting machining area.

[0091] It should be noted that, in this application, the machining feature type refers to the feature classification result used to distinguish different cutting forms and provide a basis for subsequent trajectory planning. Determining the machining feature type can transform the reconstructed target cutting machining area from an abstract geometric and topological structure into a standard feature category that can be directly identified and processed in turning. It also provides a clear process basis for subsequent tool selection, cutting parameter matching, tool path strategy formulation, and trajectory generation, enabling the control system to automatically adapt to the corresponding turning method and machining logic according to different feature types, avoiding process planning chaos, unreasonable trajectory, or machining interference caused by unclear features.

[0092] In some embodiments, generating a confidence turning tool path for the complex part based on the machining feature type can be achieved using the following steps:

[0093] Based on the machining feature type, match the corresponding turning machining process parameters and tool motion constraints, and generate the initial tool trajectory by combining the topology information of the reconstructed target cutting machining area;

[0094] The initial tool path is subjected to a cutting stability assessment to obtain a path confidence index;

[0095] The initial tool path is optimized and corrected based on the trajectory confidence index to form a confidence turning tool path for the complex part.

[0096] In specific implementation, firstly, based on the determined machining feature type, the corresponding turning machining process parameters (cutting speed, feed rate, depth of cut, and tool posture restrictions, tool path direction, and avoidance area) are matched from a pre-established turning process library. Then, combined with the topological information of the boundaries, contours, and spatial range of each machining surface within the reconstructed target cutting machining area, a path generation algorithm from CNC machining is used to plan the tool movement path according to the turning machining sequence, generating an initial tool trajectory. The path generation algorithms that can be used include the equidistant offset algorithm, the contour parallel scan algorithm, and the section line method. Taking the contour parallel scan algorithm as an example, the machining direction and tool path distance are first determined based on the machining feature type and topological information. Then, a parallel scan path is generated along the contour boundary of the target cutting machining area. The equidistant offset algorithm is used to offset the tool radius at the contour boundary to avoid overcutting. Simultaneously, tool movement constraints are incorporated, and continuous motion segments are planned according to the turning process sequence. Finally, these are combined to form the initial tool trajectory. Here, the turning machining process parameters refer to the parameters required for complete machining. The process parameters, such as cutting parameters, are set for corresponding characteristic cutting. The tool motion constraints refer to the tool motion range, posture, and path rules limited to ensure machining safety and forming quality. The initial tool trajectory refers to the tool motion path initially planned based on process parameters and topology information. Then, the cutting stability of each segment of the initial tool trajectory is judged. By quantifying the risk of tool-part collision, the direction change between trajectory segments, and whether the cutting process meets the stable feed constraint conditions (i.e., quantifying each indicator as 1 for those that exist or are met, and 0 for those that do not), the evaluation results are weighted according to preset weights to form a trajectory confidence index to characterize the reliability of the initial tool trajectory. The trajectory confidence index is a quantitative value used to characterize the safety, stability, and feasibility of the tool trajectory. Finally, when the trajectory confidence index does not reach a preset threshold, adaptive path fine-tuning is performed on the trajectory segments with insufficient cutting stability to obtain a confident turning tool trajectory for CNC machining.

[0097] It should be noted that the confidence turning tool trajectory in this application refers to the final usable tool motion trajectory of the target cutting area of ​​a complex part. Determining the confidence turning tool trajectory can complete the stability verification and optimization correction of the trajectory before CNC machining, so as to provide a standardized tool motion path with smooth movement and reliable cutting for the actual turning machining of complex parts, and provide the final executable trajectory basis for efficient and reliable automated CNC turning of complex parts.

[0098] In step S105, the complex part to be turned is machined using the confidence turning tool path.

[0099] In some embodiments, turning complex parts using the confident turning tool path can be achieved through the following steps:

[0100] The confidence turning tool trajectory is parsed into turning instructions that can be recognized by the CNC system, and the machining coordinate system calibration and cutting parameter loading are completed according to the turning instructions;

[0101] Based on the calibrated machining coordinate system and the applied cutting parameters, the turning tool is driven to perform cutting motion according to the stated turning tool trajectory, thereby completing the turning of the complex part to be machined.

[0102] In practice, firstly, the path coordinates, motion direction, feed constraints, and process-related information contained in the trusted turning tool trajectory are parsed and converted according to the common instruction specifications of CNC systems to generate turning instructions that include motion control, cutting parameters, and auxiliary functions. Then, these turning instructions are imported into the CNC system to complete the calibration and matching between the workpiece coordinate system and the machine tool coordinate system, as well as the loading of cutting parameters such as spindle speed, feed rate, and depth of cut. The turning instructions refer to the converted trusted turning tool trajectory that can be recognized and executed by the CNC system. Standardization control commands, machining coordinate system calibration refers to the coordinate alignment operation that establishes the relative positional relationship between the machine tool coordinate system and the workpiece to be machined, and cutting parameters refer to the process parameters such as spindle speed, feed rate, and depth of cut that directly control the cutting state and machining effect; then, based on the calibrated machining coordinate system and the loaded cutting parameters, output control signals to drive the machine tool spindle to rotate and the feed axis to move, so that the turning tool strictly follows the path and posture of the trusted turning tool trajectory to perform continuous cutting motion, gradually removing excess material from the workpiece, and finally completing the cutting and shaping of the complex workpiece to be machined.

[0103] Furthermore, in another aspect of this application, in some embodiments, this application provides a turning system for complex parts, referencing... Figure 3 The figure is a schematic diagram of a turning system for complex parts according to some embodiments of this application. The turning system for complex parts includes: a construction module 201, a processing module 202, and an execution module 203, which are described below:

[0104] Construction module 201, in this application, is mainly used to construct a machining surface relationship diagram based on the three-dimensional CAD model of the complex part to be machined, which describes the topological structure of the target cutting machining area;

[0105] Processing module 202, in this application, is mainly used to filter out feature extraction surfaces containing closed inner rings from the machining surface relationship diagram, and use the closed inner ring as a seed contour to search for all machining surfaces adjacent to the closed inner ring, forming a set of candidate feature surfaces for the target cutting machining area;

[0106] The processing module 202 is further configured to compare the candidate feature surface set with the preset non-machining structure surface set. If the two have a common surface, the machining surface belonging to the non-machining structure surface set is removed from the candidate feature surface set, and the topological connection relationship of the target cutting machining area is reconstructed based on multiple remaining machining surfaces that are spatially coplanar and adjacent to the same non-machining structure surface.

[0107] In addition, the processing module 202 is also used to determine the machining feature type of the target cutting machining area through the topological connection relationship of the reconstructed target cutting machining area, and then generate the confidence turning tool trajectory of the complex part according to the machining feature type;

[0108] The execution module 203 in this application is mainly used to turn complex parts to be turned by means of the confidence turning tool trajectory.

[0109] In addition, this application also provides a computer device, the computer device including a memory and a processor, the memory storing code, the processor being configured to acquire the code and execute the above-described turning method for complex parts.

[0110] In some embodiments, reference Figure 4 The figure is a schematic diagram of the structure of a computer device for implementing a turning method for complex parts according to some embodiments of this application. The turning method for complex parts in the above embodiments can be implemented by... Figure 4 The computer device shown is used to implement this, and the computer device includes at least one processor 301, a communication bus 302, a memory 303, and at least one communication interface 304.

[0111] The processor 301 may be a general-purpose central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more devices used to control the execution of the turning process for complex parts in this application.

[0112] The communication bus 302 can be used to transmit information between the aforementioned components.

[0113] The memory 303 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disks or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. The memory 303 may exist independently and be connected to the processor 301 via the communication bus 302. The memory 303 may also be integrated with the processor 301.

[0114] The memory 303 stores program code for executing the solution of this application, and its execution is controlled by the processor 301. The processor 301 executes the program code stored in the memory 303. The program code may include one or more software modules. In the above embodiments, the determination of the turning method for complex parts can be achieved by the processor 301 and one or more software modules in the program code in the memory 303.

[0115] Communication interface 304 uses any transceiver-like device for communicating with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.

[0116] In a specific implementation, as one example, a computer device may include multiple processors, each of which may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. Here, a processor may refer to one or more devices, circuits, and / or processing cores used to process data (e.g., computer program instructions).

[0117] The aforementioned computer device can be a general-purpose computer device or a special-purpose computer device. In specific implementations, the computer device can be a desktop computer, a portable computer, a network server, a handheld digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, a communication device, or an embedded device. This application does not limit the type of computer device.

[0118] In addition, this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described turning method for complex parts.

[0119] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0120] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A turning method for complex parts, characterized in that, Includes the following steps: A machining surface relationship diagram is constructed based on a 3D CAD model of a complex part to be machined, which describes the topology of the target cutting area. The process involves traversing each machining surface in the machining surface relationship graph and extracting the boundary loop information of each machining surface. Based on the boundary loop topological closure determination rule, machining surfaces with closed inner loops are identified. The machining surfaces with closed inner loops are matched and verified against a preset machining surface attribute threshold, and machining surfaces that do not meet the feature extraction conditions are eliminated. The machining surfaces with closed inner loops that pass the verification are determined as the feature extraction surfaces of the target cutting machining area. Using the closed inner loops in the feature extraction surfaces as seed contours, machining surfaces adjacent to the closed inner loops are obtained by traversing according to the topological adjacency relationship in the machining surface relationship graph. The adjacent machining surfaces are included in a temporary extended surface set, and the adjacent machining surfaces are iteratively searched based on the machining surfaces in the temporary extended surface set. All the adjacent machining surfaces obtained by the iterative search are combined with the feature extraction surfaces to form a candidate feature surface set for the target cutting machining area. The candidate feature surface set is compared with the preset non-machining structure surface set. If there is a common surface between them, the machining surface belonging to the non-machining structure surface set is removed from the candidate feature surface set. The spatial position parameters and adjacency information of the remaining machining surfaces after removing the non-machining structure surfaces are extracted. Multiple remaining machining surfaces that are spatially coplanar and adjacent to the same non-machining structure surface are selected. The selected multiple remaining machining surfaces are subjected to coplanar fusion processing to generate a fused unified machining surface. Based on the fused unified machining surface, the unfused remaining machining surfaces and their original topological associations, the topological connection relationship of the target cutting machining area is reconstructed. The topological connection relationship refers to the structured data describing the adjacency, connection and constraint relationship between each machining surface within the reconstructed target cutting machining area. The machining feature type of the target cutting machining region is determined by the topological connection relationship of the reconstructed target cutting machining region, and then a confidence turning tool trajectory of the complex part is generated according to the machining feature type. The complex parts to be machined are turned using the confidence turning tool path.

2. The method as described in claim 1, characterized in that, Based on the 3D CAD model of the complex part to be machined, a machining surface relationship diagram is constructed to describe the topology of the target cutting area. Specifically, it includes: The three-dimensional CAD model of a complex part to be turned is decomposed into a surface element and its geometric attributes are extracted to obtain the set of machining surfaces and the geometric constraint information of each machining surface. Based on the set of machining surfaces and the geometric constraint information of each machining surface, establish the adjacency, coplanarity, and intersection topological relationships between machining surfaces; Based on the topological relationships between the machining surfaces, a machining surface relationship diagram is constructed to describe the topological structure of the target cutting machining area.

3. The method as described in claim 1, characterized in that, The candidate feature surface set is compared with a preset set of unprocessed structural surfaces. If the two have a common surface, the processed surface belonging to the set of unprocessed structural surfaces is removed from the candidate feature surface set. Specifically, this includes: Extract the geometric feature parameters and surface identification information of each processed surface in the candidate feature surface set, and at the same time retrieve the preset non-processed structural surface set and the corresponding parameters of each surface therein; The geometric feature parameters and surface identification information of the candidate feature surface set are compared one by one with the corresponding parameters of the non-processed structure surface set to determine whether there is a common surface between them. If a common surface is found during the comparison, the processed surfaces that belong to the non-processed structure surface set in the candidate feature surface set are selected and removed from the candidate feature surface set.

4. The method as described in claim 1, characterized in that, Determining the machining feature type of the target cutting region by the topological connectivity of the reconstructed target cutting region specifically includes: Extract the topological connectivity of the reconstructed target cutting region and the geometric attribute information of the corresponding machining surface to construct a machining feature description vector; The machining feature description vector is matched with the feature templates in the preset turning machining feature library to obtain the matching degree parameter; The machining feature type of the target cutting area is determined based on the matching degree parameter.

5. A turning system for complex parts, used to perform the turning method for complex parts as described in any one of claims 1 to 4, characterized in that, The system includes: The module is used to construct a machining surface relationship diagram that describes the topology of the target cutting area based on the 3D CAD model of the complex part to be machined; The processing module is used to filter out feature extraction surfaces containing closed inner rings from the machining surface relationship diagram, and use the closed inner ring as a seed contour to search for all machining surfaces adjacent to the closed inner ring, forming a set of candidate feature surfaces for the target cutting machining area; The processing module is further configured to compare the candidate feature surface set with the preset non-machining structure surface set. If the two have a common surface, the machining surface belonging to the non-machining structure surface set is removed from the candidate feature surface set, and the topological connection relationship of the target cutting machining area is reconstructed based on multiple remaining machining surfaces that are spatially coplanar and adjacent to the same non-machining structure surface. The processing module is also used to determine the machining feature type of the target cutting machining area through the topological connection relationship of the reconstructed target cutting machining area, and then generate a confidence turning tool trajectory for the complex part based on the machining feature type; The execution module is used to turn complex parts to be machined by means of the confidence turning tool path.

6. A computer device, characterized in that, The computer device includes a memory and a processor, the memory storing code, and the processor being configured to retrieve the code and execute the turning method for complex parts as described in any one of claims 1 to 4.

7. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the turning method for complex parts as described in any one of claims 1 to 4.

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