A semi-automatic identification method and system for groove circular array features

Abstract

The present invention belongs to the field of product digital design and manufacturing technology, and discloses a semi-automatic identification method and system for groove circular array features, the method comprising: obtaining a part model to be identified, receiving a user's designation of a center plane of a groove as a reference feature plane; identifying all adjacent faces of the reference feature plane, calculating the distance between each adjacent face and the geometric center of the reference feature plane, and taking the adjacent face with the largest distance as a reference plane; obtaining the outer ring boundary of the reference plane, that is, all edges on the outer ring of the curved surface area to which the reference plane belongs, and obtaining the adjacent faces of the reference plane relative to the outer ring boundary; performing a center plane check on each of the adjacent faces to obtain the center planes of all grooves; based on the center plane of each groove, identifying the groove feature plane to obtain the groove circular array features of the part. The present invention is based on the analysis of the geometric properties of the groove circular array, and only requires the center plane of one groove to complete the extraction of all groove circular array features, with high recognition efficiency and accuracy.

Description

Technical Field

[0001] The invention belongs to the technical field of product digital design and manufacturing, and in particular relates to a semi-automatic recognition method and system for groove circumference array features. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Slots are a type of basic processing features that are widely used in mechanical manufacturing. According to different geometric shapes, they can be further divided into through slots, blind slots, intersecting slots, etc. The array features of slots usually appear on transmission parts, such as the tooth groove features of spur gears. The feature recognition of slots is an important research direction in feature recognition. At present, the recognition method of a single slot feature instance is relatively mature, but there are still technical problems that need to be solved for the feature recognition of the circular array of slots.

[0004] At present, the 3D machining process software system SVMAN-M of Shandong Shanda Huatian Software Co., Ltd. provides a semi-automatic recognition method for slot feature arrays under boundary surface constraints, which solves the problem of slot circular array feature recognition to a certain extent. However, the selection of boundary surfaces as constraint conditions requires high operating skills. If the selection is inappropriate, it is still easy to cause the slot circular array feature recognition to fail.

[0005] Among the solutions for slot feature recognition proposed by other research institutions, building an attribute adjacency graph and matching it with the feature library feature matrix is ​​a mainstream recognition method. This type of method constructs a meta-feature feature matrix by decomposing the target, and compares the feature information of the feature matrix with the feature information of the predefined feature library to achieve slot feature recognition. By clustering features with the same feature factor, array feature recognition can be achieved. However, the number of elements in the feature matrix is ​​the square of the number of part faces. When the number of part faces is large, the feature matrix is ​​large in size and requires a large storage space, which may lead to low computational efficiency. In addition, this type of method relies on clustering algorithms for array feature recognition. When the clustering parameters are not set properly, it is easy to confuse slot circular array features with slot features of other similar shapes. Summary of the invention

[0006] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a semi-automatic recognition method and system for groove circular array features, which performs analysis based on the geometric properties of grooves distributed in a circular array. It only needs to obtain the center plane of one groove to complete the extraction of all groove circular array features, and has high recognition efficiency and accuracy.

[0007] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0008] A method for semi-automatic recognition of groove circumference array features comprises the following steps:

[0009] Acquire a part model to be identified, and receive a user's designation of a center surface of a groove as a reference feature surface; wherein the center surface of the groove is the bottom surface of the groove;

[0010] Identify all adjacent faces of the reference feature face, calculate the distance between each adjacent face and the geometric center of the reference feature face, and use the adjacent face with the largest distance as the reference face;

[0011] Obtain the outer ring boundary of the reference surface, that is, all edges on the outer ring of the surface area to which the reference surface belongs, and obtain the adjacent faces of the reference surface relative to the outer ring boundary;

[0012] Performing a center plane check on each of the adjacent faces to obtain the center planes of all the slots;

[0013] Based on the center plane of each slot, the slot feature plane is identified to obtain the slot circumferential array feature of the part.

[0014] Further, performing center plane verification on each of the adjacent surfaces includes:

[0015] The geometric center point of the reference surface is denoted as O, the midpoint of the common edge between the reference feature surface and the reference surface is denoted as C0, and the two endpoints and the midpoint of the common edge between the adjacent surface and the reference surface are denoted as A, B and C respectively;

[0016] First determine the vector and Whether the angle is 90 degrees, if so, further determine whether the distance from point O to point C is equal to the distance from point O to point C0, if they are equal, the adjacent surface is the center surface of the groove.

[0017] One or more embodiments provide a semi-automatic recognition system for groove circumferential array features, comprising:

[0018] A part model acquisition module is used to acquire the part model to be identified;

[0019] The reference feature surface designation module is used to receive a user's designation of a center surface of a groove as a reference feature surface; wherein the center surface of the groove is the bottom surface of the groove;

[0020] A reference surface determination module, used to identify all adjacent surfaces of the reference feature surface, calculate the distance between each adjacent surface and the geometric center of the reference feature surface, and use the adjacent surface with the largest distance as the reference surface;

[0021] A candidate center plane acquisition module is used to acquire the outer ring boundary of the reference plane, that is, all edges on the outer ring of the surface area to which the reference plane belongs, and acquire adjacent faces of the reference plane relative to the outer ring boundary;

[0022] A center plane verification module, used to perform center plane verification on each of the adjacent surfaces to obtain center planes of all the slots;

[0023] The single groove feature recognition module is used to identify the groove feature surface based on the center surface of each groove, and obtain the groove circumferential array feature of the part.

[0024] One or more embodiments provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method for semi-automatic recognition of groove circular array features when executing the program.

[0025] One or more embodiments provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for semi-automatic recognition of groove circular array features.

[0026] One or more of the above technical solutions have the following beneficial effects:

[0027] For parts with straight-through groove structures and groove features distributed in a circular array, the feature recognition of each groove is converted into the center plane recognition of the groove in combination with the geometric properties of such parts. The end face of the part is determined based on a specified groove center plane, and then the center planes of other grooves are determined based on the circumferential characteristics of the part end face. Only the center plane of one groove is needed to complete the extraction of all groove circular array features, and the circular array feature recognition of the groove can be automatically completed. It has low dependence on parameters. In actual applications, users usually only need to click the mouse once to select this initial condition, which improves the ease of use of groove circular array recognition.

[0028] Moreover, the above technical solution belongs to the face-edge topology query of parts, and the algorithm has low complexity and higher speed, which can better meet the application needs of users for rapid identification of groove circular array features.

[0029] The recognition of the center plane fully considers the typical collective characteristics of the parts, and the recognition efficiency is high and the accuracy is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0031] Figure 1 A flow chart of a method for semi-automatic identification of groove circumferential array features according to one or more embodiments of the present invention;

[0032] Figure 2 It is a schematic diagram of the groove circumference array characteristics, the center plane of the groove, and the characteristic surface of the groove wheel as an example of the present invention;

[0033] Figure 3 This is a schematic diagram of the center plane verification using a sheave as an example of the present invention;

[0034] Figure 4 A flowchart of a program implementation of a method for semi-automatic identification of groove circumferential array features in one or more embodiments of the present invention;

[0035] Figure 5 The present invention is a flowchart of the center plane verification program according to one or more embodiments of the present invention. DETAILED DESCRIPTION

[0036] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0037] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0038] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0039] Embodiment 1

[0040] This embodiment discloses a semi-automatic recognition method for the circular array features of grooves, such as Figure 1 As shown, the following steps are included:

[0041] Step 1: Obtain a part model containing a groove circular array feature, and receive a user's designation of a center surface of a groove, that is, the bottom surface of the groove, as a reference feature surface.

[0042] In this embodiment, the reference feature surface f0 refers to the bottom surface of a groove, which is usually used as a reference for dimensioning of the width, depth, etc. of the groove, and is also a surface that can locate the position of a groove. Figure 2 In the example of the transmission part groove wheel, since the bottom surface of the groove has many adjacent surfaces, it not only includes the feature surfaces on both sides of the bottom surface of the groove, but also includes the end surface of the groove wheel. Using it as the reference surface for starting feature recognition helps to quickly obtain other features of the groove wheel.

[0043] After obtaining the reference feature surface in step 1, the reference feature surface is also verified to determine whether the reference feature surface is the bottom surface of the groove. Specifically, based on a single groove feature recognition method, it is determined whether the reference feature surface specified by the user can successfully perform groove recognition.

[0044] The single groove identification method can be implemented by existing technology, such as the three-dimensional machining process software system SVMAN-M. The purpose of this step is to avoid mistakes when manually specifying the center surface, and to report an error in time when the specified surface is not the center surface.

[0045] Step 2: Identify all adjacent faces of the reference feature face, calculate the distance between each adjacent face and the geometric center of the reference feature face, and use the adjacent face with the largest distance as the reference face.

[0046] As mentioned above, the surface adjacent to the reference characteristic surface f0 may be the end surface of the sheave or the characteristic surfaces on both sides of the groove bottom surface. Generally speaking, the diameter of the end surface is significantly larger than the depth of the tooth groove. Therefore, in this embodiment, the end surface of the sheave is determined based on the distance between the adjacent surface and the reference characteristic surface as the reference surface f0. ref , used to further search for other slot features.

[0047] Step 3: Identify the outer ring boundary of the reference surface, and obtain the adjacent surface of the reference surface based on the outer ring boundary.

[0048] It should be noted here that the set of common edges between the reference surface and these adjacent surfaces is the outer ring boundary.

[0049] Step 4: Perform center plane verification on adjacent surfaces of the reference surface to obtain center planes of all slots.

[0050] Specifically, for each of the adjacent faces, whether it is a central face is checked by the following steps:

[0051] (1) obtaining a common edge e between the adjacent surface and the reference surface, and obtaining endpoints A, B and a midpoint C of the common edge e;

[0052] (2) Obtain the vector representation corresponding to the common edge And the vector representation from the geometric center point O of the reference surface to the midpoint C of the common edge Determine whether the angle between the two is 90 degrees. If so, further execute step (3). If not, the adjacent surface is not the center surface.

[0053] (3) Obtain the midpoint C0 of the common edge of the reference surface and the reference feature surface, and calculate the distance from point O to point C And the distance from point O to point C0 Determine whether the two are equal. If they are equal, the adjacent face corresponding to the common edge e meets the central face requirement. If not, the adjacent face is not the central face.

[0054] The above center plane verification process fully considers the characteristics of the circular array of slot feature, and can quickly and accurately identify the center planes of all slots, thereby obtaining all feature planes of each slot based on the center plane.

[0055] Step 5: Based on the center plane of each slot, identify the slot feature surface and obtain the slot circular array feature of the part.

[0056] As a specific implementation, the above-mentioned semi-automatic identification method of the circular array feature of the groove mainly includes the following steps: inputting the center plane of the reference feature, obtaining the reference plane of the center plane of the reference feature, verifying the center plane of the reference feature, obtaining the outer ring boundary set of the reference plane, obtaining all opposite sides of the reference plane, verifying the center plane of all opposite sides, identifying the groove feature plane of all center planes, and outputting all the groove feature planes. It can be implemented in C programming language, and the program implementation flow chart is as follows: Figure 4-Figure 5 .

[0057] (1) Initialize the circular array feature geometric surface set G of the slots and the center surface set G of all the slots C , obtain the center plane f0 of the user-input reference feature, and place

[0058] (2) Query all adjacent faces of face f0, calculate the distances between the geometric centers of the adjacent faces and the geometric center of face f0 in turn, and take the adjacent face with the largest distance as the reference face f0. ref ;

[0059] (3) Perform center plane check on face f0. If it does not meet the slot center plane requirements, proceed to (8). Otherwise, add f0 to the center plane set G. C , proceed to the next step;

[0060] (4) Query and obtain the reference surface f ref The outer ring boundary set E;

[0061] (5) If the collection Then take an edge e from the set E and get the reference face f ref f, and vice versa (7);

[0062] (6) If face f∈G, then return to (5). Otherwise, check whether face f satisfies the central face condition. If face f does not satisfy the central face condition, then return to (5). Otherwise, add face f to the central face set G. C ;

[0063] (7) For the center face set G CFor each face in , use a single groove feature recognition method to identify the groove feature face, and add all the identified geometric faces to the set G;

[0064] (8) Output set G, and semi-automatic recognition of circular groove array features can be completed.

[0065] Center plane calibration, including:

[0066] (1) Take the two endpoints A and B of side e and calculate the midpoint C of AB;

[0067] (2) If the vector With vector If the angle is not equal to 90 degrees, go to (6), otherwise go to the next step;

[0068] (3) If the surface to be checked f is the reference center plane f0 input by the user, then the vector is calculated Length Reserve, go to (5), otherwise go to the next step of judgment;

[0069] (4) If the vector With vector The lengths are equal, that is If yes, go to (5); otherwise, go to (6);

[0070] (5) Output: The surface f satisfies the central surface condition;

[0071] (6) Output: Surface f does not satisfy the center surface condition.

[0072] Embodiment 2

[0073] Based on the method proposed in the first embodiment above, this embodiment provides a semi-automatic recognition system for groove circumference array features, including:

[0074] A part model acquisition module is used to acquire the part model to be identified;

[0075] The reference feature surface designation module is used to receive a user's designation of a center surface of a groove as a reference feature surface; wherein the center surface of the groove is the bottom surface of the groove;

[0076] A reference surface determination module, used to identify all adjacent surfaces of the reference feature surface, calculate the distance between each adjacent surface and the geometric center of the reference feature surface, and use the adjacent surface with the largest distance as the reference surface;

[0077] A candidate center plane acquisition module is used to acquire the outer ring boundary of the reference plane, that is, all edges on the outer ring of the surface area to which the reference plane belongs, and acquire adjacent faces of the reference plane relative to the outer ring boundary;

[0078] A center plane verification module, used to perform center plane verification on each of the adjacent surfaces to obtain center planes of all the slots;

[0079] The single groove feature recognition module is used to identify the groove feature surface based on the center surface of each groove, and obtain the groove circumferential array feature of the part.

[0080] Embodiment 3

[0081] The purpose of this embodiment is to provide an electronic device.

[0082] An electronic device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the method described in the first embodiment when executing the program.

[0083] Embodiment 4

[0084] The purpose of this embodiment is to provide a computer-readable storage medium.

[0085] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the method described in the first embodiment.

[0086] The steps involved in the above embodiments 2 to 4 correspond to the method embodiment 1, and the specific implementation methods can refer to the relevant description part of embodiment 1. The term "computer-readable storage medium" should be understood as a single medium or multiple media including one or more instruction sets; it should also be understood to include any medium that can store, encode or carry an instruction set for execution by a processor and enable the processor to execute any method in the present invention.

[0087] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A method for semi-automatic recognition of groove circumference array features, characterized in that: The following steps are involved: Acquire a model of a part to be identified, wherein the part has a through-groove structure and groove features distributed in a circular array; receiving a user's designation of a center surface of a groove as a reference feature surface; wherein the center surface of the groove is the bottom surface of the groove; Identify all adjacent faces of the reference feature face, calculate the distance between each adjacent face and the geometric center of the reference feature face, and use the adjacent face with the largest distance as the reference face; Obtain the outer ring boundary of the reference surface, that is, all edges on the outer ring of the surface area to which the reference surface belongs, and obtain the adjacent faces of the reference surface relative to the outer ring boundary; Performing a center plane check on each of the adjacent faces to obtain the center planes of all the slots; Based on the center plane of each slot, the slot feature plane is identified to obtain the slot circumference array feature of the part; Performing center plane verification on each of the adjacent faces includes: The geometric center point of the reference surface is denoted as O, the midpoint of the common edge between the reference feature surface and the reference surface is denoted as C0, and the two endpoints and the midpoint of the common edge between the adjacent surface and the reference surface are denoted as A, B and C respectively; First determine the vector and Whether the angle is 90 degrees, if so, further determine whether the distance from point O to point C is equal to the distance from point O to point C0, if they are equal, the adjacent surface is the center surface of the groove.

2. The method for semi-automatic recognition of groove circumferential array features as claimed in claim 1, characterized in that: After receiving the reference feature surface, the reference feature surface is also checked to determine whether it is a center surface.

3. The method for semi-automatic recognition of groove circumferential array features as claimed in claim 2, characterized in that: Verifying the reference characteristic surface includes: whether the characteristic surface of the groove can be successfully identified based on the reference characteristic surface.

4. A semi-automatic recognition system for groove circumference array features, characterized in that: include: A part model acquisition module, used to acquire a model of a part to be identified, wherein the part is a part having a through-groove structure and groove features distributed in a circular array; The reference feature surface designation module is used to receive a user's designation of a center surface of a groove as a reference feature surface; wherein the center surface of the groove is the bottom surface of the groove; A reference surface determination module, used to identify all adjacent surfaces of the reference feature surface, calculate the distance between each adjacent surface and the geometric center of the reference feature surface, and use the adjacent surface with the largest distance as the reference surface; A candidate center plane acquisition module is used to acquire the outer ring boundary of the reference plane, that is, all edges on the outer ring of the surface area to which the reference plane belongs, and acquire adjacent faces of the reference plane relative to the outer ring boundary; A center plane verification module, used to perform center plane verification on each of the adjacent surfaces to obtain center planes of all the slots; Performing center plane verification on each of the adjacent faces includes: The geometric center point of the reference surface is denoted as O, the midpoint of the common edge between the reference feature surface and the reference surface is denoted as C0, and the two endpoints and the midpoint of the common edge between the adjacent surface and the reference surface are denoted as A, B and C respectively; First determine the vector and Whether the angle is 90 degrees, if so, further determine whether the distance from point O to point C is equal to the distance from point O to point C0, if they are equal, the adjacent surface is the center surface of the groove; The single groove feature recognition module is used to identify the groove feature surface based on the center surface of each groove, and obtain the groove circumferential array feature of the part.

5. The semi-automatic recognition system for groove circumference array features according to claim 4, characterized in that: The single groove feature recognition module is also used to verify the reference feature surface to determine whether it is a center surface.

6. The semi-automatic recognition system for groove circumference array features according to claim 5, characterized in that: Verifying the reference characteristic surface includes: whether the characteristic surface of the groove can be successfully identified based on the reference characteristic surface.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the semi-automatic recognition method for groove circular array features as described in any one of claims 1-3 is implemented.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the semi-automatic recognition method for groove circular array features as described in any one of claims 1 to 3 is implemented.

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