Part spatial position expression method

Abstract

The invention discloses a part spatial position expression method, which comprises the following steps: firstly, acquiring a part set T and a structural member set V, acquiring a bounding box set of structural members according to the structural member set, and performing dimension reduction according to the bounding box set and the structural member set to obtain a dimension reduction plane; then projecting a part set, the structural part set and the bounding box set to the dimension reduction surface for clustering analysis, and finally outputting a spatial position expression result of the part according to a clustering analysis result. Compared with the prior art, the method has the advantages that the parts and the structural parts are processed by a unified and normative method, and the corresponding spatial position expression results are output, so that on one hand, the difference of the position expression results caused by personal experience and understanding difference is avoided, and the unification and the normative of spatial position expression are realized; the accuracy of position expression is improved; on the other hand, the method can be completed through a computer, the operation method is simple, and meanwhile the spatial position output efficiency is effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of detection equipment, and in particular to a method for expressing the spatial position of a part. Background Art

[0002] In the aviation manufacturing industry, due to the many assembly steps and complex process content of components, an assembly outline (AO) is usually used to guide the completion of production tasks. The assembly position of parts is one of the key contents that process personnel focus on in the AO.

[0003] Due to the complexity of the internal structure of an aircraft body and the fact that there is almost no similarity between the internal structures of aircraft bodies of different series and models, in the existing technology, during the AO compilation stage, process personnel manually enter the position information into the file after completing the observation of the three-dimensional digital model. For parts with a large number, similar assembly processes, and similar spatial positions, process personnel can only count the number of parts, brand names and other information, organize the content, and then manually enter it into the file.

[0004] The above operation method is not only inefficient, but also lacks standardization in manual input and different process personnel have different understandings of assembly positions, resulting in inaccurate expression of part positions. Summary of the Invention

[0005] The main purpose of this application is to provide a method for expressing the spatial position of a part, aiming to solve the defect of inaccurate part position expression in the prior art.

[0006] This application achieves the above objectives through the following technical solutions:

[0007] A method for expressing the spatial position of a part comprises the following steps:

[0008] Get the parts set T and the structural parts set V;

[0009] Acquire a bounding box set of structural components according to the structural component set;

[0010] Performing dimensionality reduction on the bounding box set and the structural component set to obtain a dimensionality reduction plane;

[0011] Projecting the parts set, the structural parts set, and the bounding box set onto the dimensionality reduction surface for cluster analysis;

[0012] Output the spatial position expression results of the parts based on the cluster analysis results.

[0013] Optionally, obtaining a set of bounding boxes of structural components according to the set of structural components includes the following steps:

[0014] Obtain the bounding boxes B1, B2, ..., B of each structural part in the set of structural parts in the aircraft global coordinate system by computer. t , where t represents the number of structural parts;

[0015] From the bounding box B i Select a first vertex and a second vertex from among the vertices of , wherein the first vertex is the point with the smallest coordinate among the vertices, and the second vertex is the point with the largest coordinate among the vertices;

[0016] Calculate the bounding box size B based on the coordinates of the first vertex and the second vertex i (a i 、b i 、c i ), where i represents the number of the structural member;

[0017] Repeat from the bounding box B i The steps of selecting the first and second vertices from each vertex of the vertices are repeated until all bounding box sizes are obtained, and the bounding box sizes are aggregated and a bounding box set {B1(a1, b1, c1), B2(a2, b2, c2), ..., B t (a t 、b t 、c t )}.

[0018] Optionally, the bounding box size Bi(ai, bi, ci) is calculated as a i =|x i1 -x i2 |,b i =|y i1 -y i2 |,c i =|z i1 -z i2 |; where x i1 、y i1 、z i1 is the coordinate of the first vertex, x i2 、y i2 、z i2 are the coordinates of the second vertex.

[0019] Optionally, performing dimensionality reduction on the bounding box set and the structural component set to obtain a dimensionality reduction plane includes the following steps:

[0020] According to the bounding box size B i (a i 、b i 、c i ), selecting a calibration structural part from the set of structural parts;

[0021] In combination with the bounding box set, a dimension reduction plane is selected from each face of the calibration structure in the three-dimensional direction.

[0022] Optionally, the calibration structure satisfies L=max(a j ,b j ,c j ), S = min (a j ,b j ,c j ),and And the name of the calibration structure contains the target keyword; j 、b j 、c j They represent the dimensional parameters of the calibrated structural parts in each three-dimensional direction, and j represents the number of the calibrated structural parts; the target keywords include beam, frame and floor.

[0023] Optionally, combining the bounding box set and selecting a dimension reduction plane from the symmetry plane of the calibration structure comprises the following steps:

[0024] Selecting a symmetric plane from among the three-dimensional faces of the calibration structure as a candidate dimensionality reduction plane;

[0025] According to the set of bounding boxes, respectively calculating the area of each bounding box in each of the candidate dimensionality reduction planes;

[0026] A dimensionality reduction plane is selected from each candidate dimensionality reduction plane according to a dimensionality reduction plane selection formula; wherein the expression of the dimensionality reduction plane selection formula is: ∑S 0t >∑S 1t And ∑S 0t >∑S 2t , where 0 represents the number of the dimensionality reduction plane, 1 and 2 represent the numbers of the remaining candidate dimensionality reduction planes, and t represents the number of the structural component.

[0027] Optionally, projecting the parts set, the structural parts set, and the bounding box set onto the dimensionality reduction surface for cluster analysis comprises the following steps:

[0028] Retrieve the dimension reduction plane;

[0029] Projecting the three-dimensional center point of each part in the part set onto the dimensionality reduction plane to obtain a part projection coordinate set;

[0030] Projecting the three-dimensional center point of each structural component in the set of structural components onto the dimensionality reduction plane to obtain a set of structural component projection coordinates;

[0031] Projecting the first and second vertex coordinates of each of the bounding boxes onto the dimensionality reduction plane to obtain a set of bounding box vertex projection coordinates;

[0032] Projecting each of the bounding box sizes onto the dimensionality reduction plane to obtain a bounding box size projection set;

[0033] Determining a number of random initial center points according to the size of each component in the set of structural components;

[0034] Calculating the initial distance between the projection coordinates of each part and each of the random initial center points respectively;

[0035] The parts are grouped according to the initial distance, and a number of calculation center points are obtained according to the grouping results.

[0036] Optionally, the number of random initial center points satisfies Where V q Indicates a structural member whose dimension in the m direction is not less than that in the n direction, V p It represents a structural member whose size in the m direction is smaller than that in the n direction. m and n represent the analysis directions of the dimensionality reduction plane, and x represents the V of the structural member. q The number of y represents the structural member V p The number of .

[0037] Optionally, grouping the parts according to the initial distance and obtaining a number of calculation center points according to the grouping results includes the following steps:

[0038] Retrieve the initial distances of any part;

[0039] Extracting a minimum value from each of the initial distances as the minimum initial distance of the part;

[0040] Dividing the parts into a set of random initial center points corresponding to the minimum initial distance;

[0041] Repeat the steps to retrieve the initial distances of any part until all parts are grouped;

[0042] Calculate the mean point of the projection coordinates of each part in the same set, use the mean point as the calculation center point, and repeat the above calculation until all calculation center points are obtained.

[0043] Optionally, outputting the spatial position expression results of the parts based on the cluster analysis results includes the following steps:

[0044] Retrieve any calculation center point and its corresponding parts sample;

[0045] Searching for a structural component closest to the calculation center point in the bounding box size projection set as a reference structural component;

[0046] Outputting a spatial position expression result based on the reference structural member as a direction reference;

[0047] Repeat the steps of calling any calculation center point and its corresponding part sample until the spatial position expression results of all parts are obtained.

[0048] Compared with the prior art, this application has the following beneficial effects:

[0049] This application first obtains a parts set T and a structural parts set V, obtains a bounding box set of structural parts based on the structural parts set, then performs dimensionality reduction based on the bounding box set and the structural parts set to obtain a dimensionality reduction plane, then projects the parts set, the structural parts set and the bounding box set onto the dimensionality reduction plane for cluster analysis, and finally outputs the spatial position expression results of the parts based on the cluster analysis results.

[0050] Solving part position information in three-dimensional space is relatively difficult. This solution designs a dimensionality reduction method based on the external dimensions of skeleton structural parts. It reduces the dimensionality of the three-dimensional space to two-dimensional space and performs cluster analysis on each part in the two-dimensional space. This allows the spatial position of each part to be expressed, effectively reducing the complexity of expressing the spatial position information of the parts.

[0051] Compared with the existing technology, first of all, this application processes each part and structural member in a unified and standardized method, and outputs the corresponding spatial position expression results. On the one hand, it avoids the differences in position expression results caused by personal experience and understanding differences, realizes the unification and standardization of spatial position expression, and improves the accuracy of position expression; on the other hand, the above method can be completed by computer, which not only has a simple operation method, but also effectively improves the efficiency of spatial position output. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A flowchart of a method for expressing the spatial position of a part provided in Example 1 of the present application.

[0053] The purpose, features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0054] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0055] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0056] In the present invention, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0057] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "robot coordinate system and / or m" as an example, it includes the robot coordinate system scheme, or the m scheme, or the scheme in which the robot coordinate system and m are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0058] Example 1

[0059] Reference Figure 1 This embodiment, as an optional embodiment of the present application, discloses a method for expressing the spatial position of a part, comprising the following steps:

[0060] S1. Obtain a set of parts T and a set of structural parts V;

[0061] Retrieve a 3D assembly model containing all parts and structural components, and obtain the parts set T and the structural component set V from the 3D assembly model;

[0062] It should be noted that structural parts refer to the skeleton parts of the product, which are usually large in size and have many details. Parts refer to the small internal parts such as clamps and signs other than the skeleton structure, which are generally small in size and simple in appearance.

[0063] S2. Obtaining a set of bounding boxes of structural components according to the set of structural components;

[0064] S21, obtaining by computer the bounding boxes B1, B2, ..., B of each structural part in the set of structural parts in the global coordinate system of the aircraft. t , where t represents the number of structural parts;

[0065] Using the API interface of the CAD software, obtain the bounding box B1, B2, ..., B of each structural part in the set of structural parts in the aircraft global coordinate system. t , where t represents the number of structural parts;

[0066] S22, from the bounding box B i Select a first vertex and a second vertex from among the vertices of , wherein the first vertex is the point with the smallest coordinate among the vertices, and the second vertex is the point with the largest coordinate among the vertices;

[0067] From each of the bounding boxes B1, B2, ..., B t Choose any bounding box B from i , where i represents the number of the structural member;

[0068] From the bounding box B i Select a first vertex and a second vertex from among the vertices of , wherein the first vertex is the point with the smallest coordinate among the vertices, and the second vertex is the point with the largest coordinate among the vertices;

[0069] S23, calculating the bounding box size B according to the coordinates of the first vertex and the coordinates of the second vertex i (a i 、b i 、c i ), where i represents the number of the structural member;

[0070] Get the coordinates of the first vertex (x i1 、y i1 、z i1 ) and the coordinates of the second vertex (x i2 、y i2 、z i2 ), substitute the above coordinates into the bounding box size B i (a i 、b i 、c i ) is calculated from the formula to get the bounding box size B i (a i 、b i 、c i ); the calculation formula is a i =|x i1 -x i2 |,bi =|y i1 -y i2 |,c i =|z i1 -z i2 |.

[0071] S24, repeat from the bounding box B i The steps of selecting the first and second vertices from each vertex of the vertices are repeated until all bounding box sizes are obtained, and the bounding box sizes are aggregated and a bounding box set {B1(a1, b1, c1), B2(a2, b2, c2), ..., B t (a t 、b t 、c t )}.

[0072] Repeat step S22 until all bounding box sizes are obtained, and then group the bounding box sizes together to create a bounding box set {B1(a1, b1, c1), B2(a2, b2, c2), ..., B t (a t 、b t 、c t )}.

[0073] S3. Perform dimensionality reduction based on the bounding box set and the structural component set to obtain a dimensionality reduction plane;

[0074] S31, according to the bounding box size B i (a i 、b i 、c i ), selecting a calibration structural part from the set of structural parts;

[0075] Retrieve the bounding box set {B1(a1, b1, c1), B2(a2, b2, c2), ..., B t (a t 、b t 、c t )}, select the bounding box size B of any structural member i (a i 、b i 、c i ), substitute its parameters into the judgment formula, if it satisfies the judgment formula, obtain the name of each structural component at the same time, and determine whether its name contains the target keyword. If the above conditions are met at the same time, the structural component is selected as the calibration structural component, otherwise it cannot be used as the calibration structural component;

[0076] Repeat the above steps and substitute the bounding box size of each structural component into the judgment formula to obtain all the calibrated structural components;

[0077] The expression of the judgment formula is L=max(a j ,b j ,c j ), S=min(a j ,b j ,c j ),and where a j 、b j 、c j Respectively represent the size parameters of the calibration structure in each three-dimensional direction; the target keywords include beam, frame and floor;

[0078] In order to effectively express the spatial position of parts, frames, beams, and bottom plate structural members that support the main structure should be selected as references. Usually, such structural members are distributed along the length of the aircraft. Connecting frames and such structural members are the most instructive references for part positions. Such structural members usually have a maximum size / minimum size of less than 0.4.

[0079] S32 . Combining the bounding box set, select a dimension reduction plane from each face of the calibration structure in the three-dimensional direction.

[0080] S321, selecting a symmetric plane from among the three-dimensional faces of the calibration structure as a candidate dimensionality reduction plane;

[0081] Based on common knowledge, in a three-dimensional coordinate system, only the XY, XZ, and YZ planes can be selected as candidate dimensionality reduction planes;

[0082] Since aircraft structures are axially symmetrical, part location planning is rarely performed using the YZ plane as a cross-section. Therefore, there are two options for dimensionality reduction analysis: the XZ plane and the XY plane. Of course, it should be noted that if the YZ plane is also a symmetric plane of the aircraft structure, it can also be used as an alternative dimensionality reduction plane. However, if the XZ plane and the XY plane are not symmetric planes of the aircraft structure, they cannot be used as alternative dimensionality reduction planes.

[0083] S322. Calculate the area of each bounding box in each candidate dimensionality reduction plane based on the bounding box set;

[0084] Retrieve the bounding box set {B1(a1, b1, c1), B2(a2, b2, c2), ..., B t (a t 、b t 、c t )}, calculate the projection area of each bounding box in the selected alternative dimensionality reduction plane, that is, for the bounding box B i (a i 、b i 、c i), its projected area in the XZ plane is a i *c i , the projected area in the XY plane is a i *b i It should be noted that if the YZ plane is also used as an alternative dimensionality reduction plane, the projected area within it is b i *c i ;

[0085] The same method is used to calculate the projected area of each bounding box in the alternative dimensionality reduction plane;

[0086] S323, selecting a dimensionality reduction plane from among the candidate dimensionality reduction planes according to a dimensionality reduction plane selection formula; wherein the expression of the dimensionality reduction plane selection formula is: ∑S 0t >∑S 1t And ∑S 0t >∑S 2t , where 0 represents the number of the dimension reduction plane, 1 and 2 represent the numbers of the remaining candidate dimension reduction planes, and t represents the number of the structural component;

[0087] Based on the projected area of each bounding box in the candidate dimensionality reduction plane calculated in step S322, the sum of all projected areas in each candidate dimensionality reduction plane is calculated; and at the same time, a dimensionality reduction plane is selected from each candidate dimensionality reduction plane according to the dimensionality reduction plane selection formula;

[0088] The expression of the dimension reduction plane selection formula is: ∑S 0t >∑S 1t And ∑S 0t >∑S 2t , where 0 represents the number of the dimension reduction plane, 1 and 2 represent the numbers of the remaining candidate dimension reduction planes, and t represents the number of the structural component;

[0089] That is, the alternative dimensionality reduction plane that satisfies the above formula is the dimensionality reduction plane. If there are only two alternative dimensionality reduction planes, the one with the larger sum of areas is selected as the dimensionality reduction plane. If there are three alternative dimensionality reduction planes, the one with the largest sum of areas is selected as the dimensionality reduction plane.

[0090] S4, projecting the parts set, the structural parts set, and the bounding box set onto the dimensionality reduction surface for cluster analysis;

[0091] Cluster analysis is an unsupervised method that divides samples in a data set into multiple classes so that samples in the same class are similar to each other. In the technical solution described in this application, cluster analysis can obtain sample points corresponding to multiple parts with similar distances. These sample points enhance the generalization ability of spatial position expression and effectively reduce the complexity of expressing the spatial position of parts.

[0092] S41, retrieve the dimension reduction plane;

[0093] S42, projecting the three-dimensional center point of each part in the part set onto the dimensionality reduction plane to obtain a part projection coordinate set;

[0094] The three-dimensional center point coordinates of each part are calculated by computer, and then each three-dimensional center point is projected onto the dimensionality reduction plane;

[0095] If the calculated coordinates of the three-dimensional center point of a part are (x1, y1, z1), and the selected dimensionality reduction plane is the XY plane, then the coordinates after projection are (x1, y1);

[0096] Calculate the 3D centers of all parts separately and project them all to obtain the part projection coordinate set;

[0097] S43, projecting the three-dimensional center point of each structural component in the set of structural components onto the dimensionality reduction plane to obtain a set of structural component projection coordinates;

[0098] Perform projection according to the method described in step S42 to obtain a set of projection coordinates of the structural component;

[0099] S44, projecting the dimensional coordinates of the first vertex and the second vertex of each of the bounding boxes onto the dimensionality reduction plane to obtain a set of bounding box vertex projection coordinates;

[0100] Perform projection according to the method described in step S42 to obtain a set of projection coordinates of the bounding box vertices;

[0101] S45, projecting the sizes of the bounding boxes onto the dimensionality reduction plane to obtain a set of bounding box size projections;

[0102] The bounding box set {B1(a1, b1, c1), B2(a2, b2, c2), ..., B t (a t 、b t 、c t )} choose a bounding box size B i (a i 、b i 、c i ), and assuming that the selected dimensionality reduction plane is the XY plane, the size of the bounding box after projection is (a i 、b i );

[0103] Repeat the above steps to obtain the bounding box sizes after all projections to create a bounding box size projection set;

[0104] S46, determining a number of random initial center points according to the size of each component in the set of structural components;

[0105] Retrieve the bounding box size projection set obtained in step S45 and analyze the size parameters in two analysis directions of the dimensionality reduction plane (e.g., if the XY plane is selected, the X and Y directions are the two analysis directions); classify each structural component according to the size parameters and count the number of each type of structural component; finally, calculate the number of random initial center points;

[0106] The number of random initial center points satisfies Where V q Indicates a structural member whose dimension in the m direction is not less than that in the n direction, V p It represents a structural member whose size in the m direction is smaller than that in the n direction. m and n represent the analysis directions of the dimensionality reduction plane, and x represents the V of the structural member. q The number of y represents the structural member V p The number of

[0107] S47, respectively calculating the initial distance between the projection coordinates of each part and each of the random initial center points;

[0108] Obtain the part projection coordinate set calculated in step S42, and randomly generate a corresponding number of random initial center points by the computer according to the number of random initial center points calculated in step S46;

[0109] According to the distance calculation formula, the initial distance between each part projection coordinate and each of the random initial center points is calculated respectively.

[0110] It should be noted that if the parts involved are D1, D2, ..., D n , the random initial center points are E1, E2, ..., E k , then the calculated part D1 involves initial distances including D1E1, D1E2, ..., D1E k , the initial distances of other parts can be obtained in the same way; where D1E1 represents the initial distance between part D1 and the random initial center point E1;

[0111] S48, grouping the parts according to the initial distance, and obtaining a number of calculation center points based on the grouping results;

[0112] S481, retrieve the initial distances of any part;

[0113] S482, extracting a minimum value from each of the initial distances as the minimum initial distance of the part;

[0114] For example, when retrieving part D1, the initial distances D1E1, D1E2, ..., D1E k , obtain the minimum initial distance from the above initial distances as the minimum initial distance, such as D1E kis the minimum initial distance;

[0115] S483, dividing the parts into a set of random initial center points corresponding to the minimum initial distance, calculating the mean point of the projection coordinates of each part in the same set as the new center point of the set;

[0116] The minimum initial distance of all parts can be obtained based on the division result in step S482. Based on the minimum initial distance, the parts corresponding to the same random initial center point are divided into the same set, and the set also includes the random initial center point.

[0117] If the minimum initial distance obtained is D1E k , D2E2, D3E2, D4E k 、D5E3、...、D n E k , then parts D1, D4, ..., D n and a random initial center point E k Divide into the same set;

[0118] S484, repeat the steps to retrieve the initial distances of any part until all parts are grouped;

[0119] S485, calculating the mean point of the projection coordinates of each part in the same set, taking the mean point as the new calculation center point, and repeating the above calculation until the center point no longer changes;

[0120] Calculate the mean point of the projection coordinates of each part in the same set by a computer, and use the mean point as the calculation center point;

[0121] During the assembly process, parts are assembled on structural parts. During assembly, it is necessary to pay attention to the spatial position relationship between structural parts and parts. This application uses clustering analysis technology to objectively and accurately construct the spatial position relationship between structural parts and parts, which is conducive to improving the accuracy of position expression.

[0122] S5. Output the spatial position expression results of the parts based on the cluster analysis results.

[0123] S51, retrieve any calculation center point and its corresponding part sample;

[0124] S52, searching the bounding box size projection set for a structural component closest to the calculation center point as a reference structural component;

[0125] Obtain the projection coordinate set of the structural component calculated in step S43, and simultaneously obtain the various calculation center points calculated in step S485;

[0126] Calculate the distance between each structural member and each calculation center point respectively, and select the structural member with the shortest distance to the center point as the reference structural member;

[0127] For example, for the calculation center point O1, the distances between each structural member and it are O1V1, O1V2, O1V3, ..., O1V r , where the structural part O1V3 is the smallest, then the structural part V3 is selected as the reference structural part corresponding to the calculation center point O1; each part in the same set as the calculation center point O1 uses the structural part V3 as the reference structure to output the spatial position expression result;

[0128] S53, outputting a spatial position expression result based on the reference structural member as a direction reference;

[0129] The general expression of the spatial position expression result is: part Di is located above / below / left / right of the structural part Vi.

[0130] It's important to note that an aircraft coordinate system typically consists of three orthogonal axes: the horizontal (X), vertical (Y), and vertical (Z) axes. Therefore, the general formula is: Part Di is located above / below / left / right / front / back of structural component Vi. The direction is determined by the components of the direction vector from the structural component to the part along the coordinate axes, with the largest component being used to describe the direction. The X direction represents left / right, the Y direction represents front / back, and the Z direction represents up / down.

[0131] In conjunction with the dimensionality reduction plane, the specific general formula is as follows: If the dimensionality reduction plane is the XY plane, then part Di is located in front of / back of / left of / right of structural member Vi, with the X direction representing left / right and the Y direction representing front / back. Similarly, if the dimensionality reduction plane is the YZ plane, part Di is located in front of / back of / upper / lower of structural member Vi, with the Y direction representing front / back and the Z direction representing top / bottom. If the dimensionality reduction plane is the XZ plane, part Di is located in left / right of / upper / bottom of structural member Vi, with the X direction representing left / right and the Z direction representing top / bottom.

[0132] S54, repeat the steps of retrieving any calculation center point and its corresponding part sample until the spatial position expression results of all parts are obtained;

[0133] Compared with the existing technology, first of all, this application processes each part and structural member in a unified and standardized method, and outputs the corresponding spatial position expression results. On the one hand, it avoids the differences in position expression results caused by personal experience and understanding differences, realizes the unification and standardization of spatial position expression, and improves the accuracy of position expression; on the other hand, the above method can be completed by computer, which not only has a simple operation method, but also effectively improves the efficiency of spatial position output.

[0134] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for expressing the spatial position of a part, characterized in that: The following steps are involved: Get the parts set T and the structural parts set V; Acquire a bounding box set of structural components according to the structural component set; Performing dimensionality reduction on the bounding box set and the structural component set to obtain a dimensionality reduction plane; Projecting the parts set, the structural parts set, and the bounding box set onto the dimensionality reduction surface for cluster analysis; Output the spatial position expression results of the parts based on the cluster analysis results.

2. A method for expressing the spatial position of a part according to claim 1, characterized in that: The step of obtaining a bounding box set of structural components according to the structural component set includes the following steps: Obtain the bounding boxes B1, B2, ..., B of each structural part in the set of structural parts in the aircraft global coordinate system by computer. t , where t represents the number of structural parts; From the bounding box B i Select a first vertex and a second vertex from among the vertices of , wherein the first vertex is the point with the smallest coordinate among the vertices, and the second vertex is the point with the largest coordinate among the vertices; Calculate the bounding box size B based on the coordinates of the first vertex and the second vertex i (a i 、b i 、c i ), where i represents the number of the structural member; Repeat from the bounding box B i The steps of selecting the first and second vertices from each vertex of the vertices are repeated until all bounding box sizes are obtained, and the bounding box sizes are aggregated and a bounding box set {B1(a1, b1, c1), B2(a2, b2, c2), ..., B t (a t 、b t 、c t )}.

3. A method for expressing the spatial position of a part according to claim 2, characterized in that: The calculation formula of the bounding box size Bi(ai, bi, ci) is a i =|x i1 -x i2 |,b i =|y i1 -y i2 |,c i =|z i1 -z i2 |; where x i1 、y i1 、z i1 is the coordinate of the first vertex, x i2 、y i2 、z i2 are the coordinates of the second vertex.

4. A method for expressing the spatial position of a part according to claim 1, characterized in that: The performing dimensionality reduction according to the bounding box set and the structural component set to obtain a dimensionality reduction plane includes the following steps: According to the bounding box size B i (a i 、b i 、c i ), selecting a calibration structural part from the set of structural parts; In combination with the bounding box set, a dimension reduction plane is selected from each face of the calibration structure in the three-dimensional direction.

5. A method for expressing the spatial position of a part according to claim 4, characterized in that: The calibration structure satisfies L=max(a j ,b j ,c j ), S=min(a j ,b j ,c j ),and And the name of the calibration structure contains the target keyword; j 、b j 、c j They represent the dimensional parameters of the calibrated structural parts in each three-dimensional direction, and j represents the number of the calibrated structural parts; the target keywords include beam, frame and floor.

6. A method for expressing the spatial position of a part according to claim 4, characterized in that: The step of combining the bounding box set and selecting a dimension reduction plane from the symmetry plane of the calibration structure comprises the following steps: Selecting a symmetric plane from among the three-dimensional faces of the calibration structure as a candidate dimensionality reduction plane; According to the set of bounding boxes, respectively calculating the area of each bounding box in each of the candidate dimensionality reduction planes; A dimensionality reduction plane is selected from each candidate dimensionality reduction plane according to a dimensionality reduction plane selection formula; wherein the expression of the dimensionality reduction plane selection formula is: ∑S 0t >∑S 1t And ∑S 0t >∑S 2t , where 0 represents the number of the dimensionality reduction plane, 1 and 2 represent the numbers of the remaining candidate dimensionality reduction planes, and t represents the number of the structural component.

7. A method for expressing the spatial position of a part according to claim 1, characterized in that: Projecting the parts set, the structural parts set, and the bounding box set onto the dimensionality reduction surface for cluster analysis comprises the following steps: Retrieve the dimension reduction plane; Projecting the three-dimensional center point of each part in the part set onto the dimensionality reduction plane to obtain a part projection coordinate set; Projecting the three-dimensional center point of each structural component in the set of structural components onto the dimensionality reduction plane to obtain a set of structural component projection coordinates; Projecting the first and second vertex coordinates of each of the bounding boxes onto the dimensionality reduction plane to obtain a set of bounding box vertex projection coordinates; Projecting each of the bounding box sizes onto the dimensionality reduction plane to obtain a bounding box size projection set; Determining a number of random initial center points according to the size of each component in the set of structural components; Calculating the initial distance between the projection coordinates of each part and each of the random initial center points respectively; The parts are grouped according to the initial distance, and a number of calculation center points are obtained according to the grouping results.

8. A method for expressing the spatial position of a part according to claim 7, characterized in that: The number of random initial center points satisfies Where V q Indicates a structural member whose dimension in the m direction is not less than that in the n direction, V p It represents a structural member whose size in the m direction is smaller than that in the n direction. m and n represent the analysis directions of the dimensionality reduction plane, and x represents the V of the structural member. q The number of y represents the structural member V p The number of .

9. A method for expressing the spatial position of a part according to claim 7, characterized in that: The method of grouping the parts according to the initial distance and obtaining a plurality of calculation center points according to the grouping results includes the following steps: Retrieve the initial distances of any part; Extracting a minimum value from each of the initial distances as the minimum initial distance of the part; Dividing the parts into a set of random initial center points corresponding to the minimum initial distance; Repeat the steps to retrieve the initial distances of any part until all parts are grouped; Calculate the mean point of the projection coordinates of each part in the same set, use the mean point as the calculation center point, and repeat the above calculation until all calculation center points are obtained.

10. A method for expressing the spatial position of a part according to claim 9, characterized in that: Outputting the spatial position expression result of the part according to the cluster analysis result includes the following steps: Retrieve any calculation center point and its corresponding parts sample; Searching for a structural component closest to the calculation center point in the bounding box size projection set as a reference structural component; Outputting a spatial position expression result based on the reference structural member as a direction reference; Repeat the steps of calling any calculation center point and its corresponding part sample until the spatial position expression results of all parts are obtained.

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