CN114626602A

CN114626602A - Method and system for improving precision of assembly interference magnitude

Info

Publication number: CN114626602A
Application number: CN202210241666.0A
Authority: CN
Inventors: 秦小森; 吕国艳; 黄鹏; 支运龙; 王庆磊
Original assignee: CRRC Qingdao Sifang Co Ltd
Current assignee: CRRC Qingdao Sifang Co Ltd
Priority date: 2022-03-11
Filing date: 2022-03-11
Publication date: 2022-06-14

Abstract

The invention discloses a method and a system for improving precision of assembly interference, which comprises the following steps: acquiring an interference magnitude value of each component A and each component B which need to be subjected to interference assembly; constructing a first matrix of component A and component B interference magnitudes; setting an expected interference magnitude value, subtracting the expected interference magnitude value from each element value in the first matrix, and taking an absolute value to obtain a second matrix; respectively carrying out row specification and column specification on the second matrix to obtain a third matrix; marking the zero elements in the third matrix according to a set rule, and if the number of the marked zero elements is equal to the number of the components A or the components B, determining the data of the corresponding position in the first matrix corresponding to the marked zero elements as the optimal solution for assembling the components A and the components B; otherwise, after the third matrix is processed, marking the zero elements again until the number of the marked zero elements is equal to that of the parts A or B, and further obtaining the optimal assembly solution of the parts A and B.

Description

Method and system for improving precision of assembly interference magnitude

Technical Field

The invention relates to the technical field of component assembly, in particular to a method and a system for improving assembly interference accuracy.

Background

The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.

During the assembly process of the rail vehicle, a large number of parts are often required to be assembled in an interference manner; such as: in the assembling process of the vehicle bogie, the press mounting of the axle and the wheel, the axle and the bearing, various rubber nodes and ends and the like are required to be subjected to interference assembly.

In the existing assembly process, under the condition that the requirement of an interference range is met, most of parts A, B are selected manually, so that the random selection has strong randomness, the press-fitting interference distribution of parts in the same batch is easily uneven, the repeatability is poor, the manual matching workload is large, unqualified products are occasionally generated, and the matching efficiency and quality are difficult to guarantee.

The Hungarian algorithm is widely used for solving the assignment problem, wherein the assignment problem refers to the problem that m persons need to complete n tasks, how to assign the relationship between the persons and the tasks leads to the lowest cost for completing the tasks or the largest task amount within the same time, and if m is n, the problem is a balance problem; if m ≠ n, the problem is unbalanced.

At present, a technical scheme for solving the problem of the matching relationship between two parts by using the Hungarian algorithm is not found.

Disclosure of Invention

In order to solve the problems, the invention provides a method and a system for improving the precision of assembly interference, and the assignment problem is generalized to the matching relation between the component A and the component B based on the design idea of Hungarian algorithm, so that the assignment problem which tends to be a specified value can be solved; the qualification rate of the press-fitting components in the same batch can be improved, and meanwhile, the magnitude of interference can be accurately controlled, so that the assembling quality is improved.

According to a first aspect of the embodiments of the present invention, there is provided a method for improving accuracy of assembly interference, including:

acquiring an interference magnitude value of each component A and each component B which need to be subjected to interference assembly; increasing the number of the parts to be less, so that the number of the parts A and B is the same;

constructing a first matrix of component A and component B interference magnitudes; setting an expected interference magnitude value, subtracting the expected interference magnitude value from each element value in the first matrix, and taking an absolute value to obtain a second matrix;

performing row specification and column specification on the second matrix respectively to obtain a third matrix;

marking the zero elements in the third matrix according to a set rule, and if the number of the marked zero elements is equal to the maximum number of the components A or the components B, determining the data of the corresponding position in the first matrix corresponding to the marked zero elements as the optimal assembly solution of the components A and the components B; otherwise, after the third matrix is processed, marking the zero elements again until the number of the marked zero elements is equal to that of the parts A or B, and further obtaining the optimal assembly solution of the parts A and B.

According to a second aspect of the embodiments of the present invention, there is provided a system for improving accuracy of assembly interference, including:

the data acquisition module is used for acquiring the interference magnitude of each component A and each component B which need to be subjected to interference assembly; increasing the number of the parts to be less, so that the number of the parts A and B is the same;

a data processing module for constructing a first matrix of component A and component B interference magnitudes; setting an expected interference magnitude value, subtracting the expected interference magnitude value from each element value in the first matrix, and taking an absolute value to obtain a second matrix; performing row specification and column specification on the second matrix respectively to obtain a third matrix;

the optimal solution matching module is used for marking the zero elements in the third matrix according to a set rule, and if the number of the marked zero elements is equal to the maximum number of the components A or B, the data of the corresponding position in the first matrix corresponding to the marked zero elements is the optimal solution for assembling the components A and B; otherwise, after the third matrix is processed, marking the zero elements again until the number of the marked zero elements is equal to that of the parts A or B, and further obtaining the optimal assembly solution of the parts A and B.

According to a third aspect of the embodiments of the present invention, there is provided a terminal device, which includes a processor and a memory, the processor being configured to implement instructions; the memory is used for storing a plurality of instructions which are suitable for being loaded by the processor and executing the method for improving the precision of the assembly interference.

According to a fourth aspect of the embodiments of the present invention, there is provided a computer-readable storage medium, in which a plurality of instructions are stored, the instructions being adapted to be loaded by a processor of a terminal device and to perform the above-mentioned method for improving accuracy of assembly interference.

Compared with the prior art, the invention has the beneficial effects that:

(1) the assembly problem of parts is equivalent to an assignment problem through an improved Hungarian algorithm, an operator can manually set an expected interference magnitude value (the value is in an interference range of process requirements), and the system performs optimal matching association on all current parts A, B, so that the average value of all A, B assembly interference magnitudes is closest to an artificial set value.

(2) The method improves the precision of the assembly process, ensures that the press-fitting interference magnitude of the whole batch of parts can have artificial guidance on the premise of meeting the process requirements, and improves the quality of the assembly operation.

(3) The method of the present invention facilitates operator determination of the fitting relationship for the component A, B and the fitting relationship can be recorded and traced.

Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

Fig. 1 is a flowchart of a method for improving accuracy of assembly interference in an embodiment of the present invention.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise, and it should be understood that the terms "comprises" and "comprising", and any variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The embodiments and features of the embodiments of the present invention may be combined with each other without conflict.

Example one

In one or more embodiments, a method for improving accuracy of assembly interference is disclosed, and with reference to fig. 1, the method specifically includes the following steps:

s101: acquiring an interference magnitude value of each component A and each component B which need to be subjected to interference assembly; in this embodiment, the size values of the component a and the component B that need to be subjected to interference fit are measured, and the difference between the sizes of the two is the interference magnitude. As shown in table 1, assuming that the dimension B of the component B is larger than the dimension a of the component a, the interference is (B-a). The interference values are solved for each of the components a and B to form table 1, and for the convenience of describing the embodiment of the present invention, specific values of the interference, in mm, are given in parentheses.

TABLE 1

In addition, if the number of components a and B is not equal, the imbalance problem needs to be first converted to a balance problem; the method specifically comprises the following steps: increasing the number of the parts to be less, so that the number of the parts A and B is the same;

in table 1, the number of parts B is less than the number of parts a, and therefore, the virtual part B5 is added, and the interference value of B5 with each part a is 0; as shown in table 2.

TABLE 2

Similarly, if the number of the components a is smaller than that of the components B, a virtual component a is added, and the interference value with each component B is 0.

S102: constructing a first matrix of component A and component B interference magnitudes; setting an expected interference magnitude value, subtracting the expected interference magnitude value from each element value in the first matrix, and taking an absolute value to obtain a second matrix;

specifically, using the above interference magnitudes for part a and part B, which translate into a balance problem, a first matrix is constructed, as in table 2; in this embodiment, the expected interference value is set as c (0.1), and then the expected interference value is subtracted from each element value in the first matrix, and the absolute value is taken to obtain the second matrix, as shown in table 3.

TABLE 3

S103: performing row specification and column specification on the second matrix respectively to obtain a third matrix;

in this embodiment, row reduction and column reduction are performed on the second matrix, which specifically includes: subtracting the minimum value of each row element in the second matrix; the minimum value for each column is then subtracted from the elements of that column.

In this embodiment, the minimum value of each row in table 3 is subtracted from the element value of the row to obtain table 4; then row and column specifications, for each column element value subtracting the minimum value of the column; because the minimum value in each column in table 4 is zero, the value of the element in each column is unchanged.

TABLE 4

S104: marking the zero elements in the third matrix according to a set rule, and if the number of the marked zero elements is equal to the maximum number of the components A or B, determining the data of the corresponding position in the first matrix corresponding to the marked zero elements as the optimal assembly solution of the components A and B; otherwise, after the third matrix is processed, marking the zero elements again until the number of the marked zero elements is equal to that of the parts A or B, and further obtaining the optimal assembly solution of the parts A and B.

Marking zero elements in the third matrix according to a set rule, specifically: finding the row with the least zero elements in the third matrix, marking the zero elements in the row, and scratching out the zero elements of the row and the column where the marked zero elements are located; and repeating the process until all the zero elements in the third matrix are processed.

The process of processing the third matrix specifically includes:

labeling the rows without the marked zero elements in a set form;

marking the columns with the drawn zero elements in the rows without the marked zero elements in a set form;

in the marked column, marking the line where the marked zero element is positioned in a set form;

scratching out elements in rows which are not marked and scratching out elements in marked columns; thereby achieving coverage of all zero elements with the least number of lines.

Then, the elements in the marked rows and columns are adjusted, specifically: finding the minimum of the non-zero elements in the labeled row and column; subtracting the minimum value from each non-zero element in the labeled row, and adding the minimum value to each non-zero element in the labeled column; and finally obtaining a processed third matrix.

As a specific embodiment, in table 4, all the zero elements in rows 2 to 4 are 1, and all the zero elements are the rows with the least zero elements, where row 2 is selected; marking the zero elements in the row (in the embodiment, a circling mode is selected for marking, and the circling action is shown in a background color; and a person skilled in the art can select other marking modes as required); zero elements in the rows and columns (shown underlined) where the marked zero element is located are scribed; this step is repeated until all zero elements in the matrix have been processed. Table 5 was obtained, and the numbers in the circles in table 5 represent the order of the loops.

TABLE 5

If the number of 0 is equal to the maximum number of the components A (or B), the data in the original table (table 2) corresponding to the element 0 is the optimal solution; otherwise (number 4 ≠ 5 of 0 in table 5), the following steps are performed:

(1) marking the rows without marking zero elements (i.e. the rows without circles) in a set form (marking is performed in a manner of v √ in this embodiment, and those skilled in the art can select other marking manners as needed);

(2) marking the columns of the zero elements with the drawn lines in the rows without the marked zero elements by V-shaped marks;

(3) marking V-shaped marks on rows with marked zero elements in the V-shaped marked columns;

(4) straight lines (represented here by double-dashed lines) are drawn for the elements in the rows without a check mark and the columns with a check mark, as shown in table 6. The numbers of circles in table 6 indicate the order of marking by √ marks.

TABLE 6

Adjusting the element values in the rows and columns marked by the squares in the table 6, wherein the specific adjustment strategy is as follows:

(1) finding the minimum of all non-zero elements in the circled rows and columns (bold values 0.01 in table 6);

(2) subtracting the minimum value from all non-zero elements in the marked rows;

(3) this minimum value is added to all non-zero elements in the circled columns.

Table 7 was finally obtained:

TABLE 7

Taking the matrix in the table 7 as a new third matrix, and repeating the above processing of the elements in the third matrix until the number of marked zero elements is equal to the maximum one of the numbers of the parts a or B; at this time, the obtained actual data of the zero element in the matrix corresponding to the corresponding position in table 2 is the optimal solution.

In this embodiment, the looping and scribing process is performed on the matrix elements of table 7 to obtain table 8, the number of zero elements of the matrix marks in table 8 is 4, and the adjustment needs to be continued to obtain table 9, at this time, the number of zero elements of the matrix marks in table 9 is 5, and is the same as the number of the components a, and the actual data in table 2 corresponding to the zero elements of the marks in table 9 is the optimal solution. At this time, the average value of the interference is [ (0.12+0.09+0.12+0.1) -0.4]/4 ═ 0.1125, which is the combination closest to the expected value of interference of 0.1 in the size database of the current component A, B; the optimal solution is stored, and later-period tracing is facilitated.

TABLE 8

TABLE 9

The method of the embodiment can ensure that the interference magnitude of a certain batch of two parts participating in assembly has artificial guidance; based on the method, the mean value of the interference of the parts to be assembled in a certain batch is closest to an artificial set value, so that the assembly quality is improved; the matching of the parts can be rapidly carried out, and the part numbers and the interference values participating in assembly can be recorded and traced.

Example two

In one or more embodiments, a system for improving accuracy of assembly interference is disclosed, comprising:

the optimal solution matching module is used for marking the zero elements in the third matrix according to a set rule, and if the number of the marked zero elements is equal to the number of the components A or the components B, the data of the corresponding positions in the first matrix corresponding to the marked zero elements is the optimal solution for assembling the components A and the components B; otherwise, after the third matrix is processed, marking the zero elements again until the number of the marked zero elements is equal to that of the parts A or B, and further obtaining the optimal assembly solution of the parts A and B.

It should be noted that, the specific implementation of each module described above has been described in the first embodiment, and is not described in detail here.

EXAMPLE III

In one or more embodiments, a terminal device is disclosed, which includes a server including a memory, a processor, and a computer program stored on the memory and executable on the processor, and the processor executes the computer program to implement the method for improving accuracy of assembly interference in the first embodiment. For brevity, no further description is provided herein.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described in terms of flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.

Claims

1. A method for improving precision of assembly interference magnitude is characterized by comprising the following steps:

2. The method for improving the precision of the assembly interference magnitude according to claim 1, wherein the sizes of all the parts A and B needing interference assembly are measured, and the interference magnitude of each part A and each part B is calculated; the added component is taken as a virtual component, and the interference magnitude with each other component is zero.

3. The method for improving accuracy of assembly interference according to claim 1, wherein said second matrix is row-wise and column-wise specified, respectively, by: subtracting the minimum value of the corresponding row from each row element in the second matrix; the minimum value of the corresponding column is then subtracted from each column element.

4. The method for improving the accuracy of the assembly interference magnitude according to claim 1, 2 or 3, wherein the zero elements in the third matrix are marked according to a set rule, specifically:

finding the row with the least zero elements in the third matrix, marking the zero elements in the row, and scratching out the zero elements of the row and the column where the marked zero elements are located;

and repeating the process until all the zero elements in the third matrix are processed.

5. The method for improving the accuracy of the assembly interference according to claim 4, wherein otherwise, the processing of the third matrix specifically comprises:

labeling the rows without the marked zero elements in a set form;

scratching out elements in rows which are not marked and scratching out elements in marked columns;

and adjusting elements in the marked rows and columns to obtain a processed third matrix.

6. The method for improving accuracy of assembly interference according to claim 4, wherein the elements in the labeled rows and columns are adjusted by:

finding the minimum of the non-zero elements in the labeled row and column;

subtracting the minimum value from each non-zero element in the labeled row and adding the minimum value to each non-zero element in the labeled column.

7. The method for improving the accuracy of the assembly interference according to claim 4, further comprising: and storing the optimal assembly solution of the component A and the component B.

8. A system for improving assembly interference accuracy, comprising:

9. A terminal device comprising a processor and a memory, the processor being arranged to implement instructions; the memory is configured to store a plurality of instructions adapted to be loaded by the processor and to perform the method of improving accuracy of fit interference according to any of claims 1-7.

10. A computer-readable storage medium having stored thereon a plurality of instructions, wherein the instructions are adapted to be loaded by a processor of a terminal device and to perform the method for improving accuracy of fit interference according to any one of claims 1 to 7.