CN114782315B

CN114782315B - Shaft hole assembly pose precision detection method, device, equipment and storage medium

Info

Publication number: CN114782315B
Application number: CN202210266335.2A
Authority: CN
Inventors: 吴丹; 盖宇航; 张继文; 徐静; 王国磊
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Filing date: 2022-03-17
Publication date: 2024-07-09
Anticipated expiration: 2042-03-17

Abstract

The application discloses a detection method and device for shaft hole assembly pose precision, electronic equipment and a storage medium, wherein the method comprises the following steps: firstly, carrying out space three-dimensional shape detection and axle center fitting on the hole and the axle; thereafter, the hole and the shaft surface are pre-coated with a photo-curable resin before assembly. After the assembly is performed, the resin is solidified by ultraviolet irradiation, and the fixed connection of the hole and the shaft is ensured. Selecting a specific section as a section plane according to the three-dimensional shape detection result of the hole and shaft space, and milling a section plane of the assembled shaft hole along the selected section plane; detecting the plane two-dimensional shape of the hole and the shaft in the section; and finally, recovering the inner hole of the section and the axis of the shaft, and detecting the assembly accuracy. Thus, closely matched mating surface type data is accurately detected. Therefore, the problems of shaft hole assembly precision detection and the like are solved.

Description

Shaft hole assembly pose precision detection method, device, equipment and storage medium

Technical Field

The application relates to the technical field of precision detection, in particular to a method and a device for detecting shaft hole assembly pose precision, electronic equipment and a storage medium.

Background

Shaft hole assembly is one of the most common types of assembly in industrial products. For the high-precision shaft hole assembly task, the axiality and the axis inclination between the shaft and the hole are required to be strictly ensured in the assembly process.

In the related art, the contact type detection method (a probe type three-coordinate measuring machine) can accurately detect the data of the outer surface of an object, but cannot detect the data of the matched surface after the assembly is completed; non-contact type detection methods (e.g., industrial CT, ultrasound) cannot accurately detect mating surface type data of a close fit (gap amount <5 microns), and are in need of solution.

Disclosure of Invention

The application provides a method and a device for detecting shaft hole assembly pose precision, electronic equipment and a storage medium, and aims to solve the problems of shaft hole assembly precision detection and the like.

An embodiment of a first aspect of the present application provides a method for detecting shaft hole assembly pose accuracy, including the following steps: constructing a space three-dimensional shape of a hole and a shaft by utilizing pre-acquired hole inner side wall surface shape point cloud data and shaft outer side wall surface shape point cloud data of the shaft hole assembly, and performing axis fitting on the space three-dimensional shape of the hole and the shaft to obtain a first axis; a first shaft hole section is obtained by cutting a section of the assembled shaft hole according to the space three-dimensional shapes of the hole and the shaft, and a first hole section and a first shaft section with highest similarity with the first shaft hole section in the space three-dimensional shapes of the hole and the shaft are respectively determined through data alignment; and respectively obtaining the coordinates of a second axis corresponding to the first hole section and the coordinates of a third axis corresponding to the first shaft section through the coordinate relation of the first axis, and calculating the inclination and coaxiality between the second axis and the third axis according to the coordinates of the second axis and the coordinates of the third axis so as to determine the shaft hole assembly pose precision of the shaft hole assembly.

Optionally, in an embodiment of the present application, the performing axis fitting on the spatial three-dimensional shapes of the hole and the shaft to obtain a first axis includes: when the side wall of a hole or a shaft assembled in the shaft hole is a cylindrical surface, constructing a cylindrical space three-dimensional shape according to the point cloud data of the surface shape of the inner side wall of the hole and the point cloud data of the surface shape of the outer side wall of the shaft, and taking the cylindrical axis as the first axis; and when part of the side wall of the hole or the shaft assembled in the shaft hole is a cylindrical surface, screening point cloud data with the side wall being the cylindrical surface from the point cloud data of the surface shape of the inner side wall of the hole and the point cloud data of the surface shape of the outer side wall of the shaft, and constructing a cylindrical space three-dimensional shape according to the screened point cloud data, wherein the cylindrical axis is used as the first axis.

Optionally, in an embodiment of the present application, after the axis fitting the spatial three-dimensional shapes of the hole and the shaft to obtain the first axis, the method further includes: constructing an initial equation of the first axis in a shaft hole assembly coordinate system, and determining initial parameters of the initial equation according to a fitting process; constructing an error equation of the initial equation, and solving the error equation by using a linearization least square method to obtain a linearized error equation; bringing the point cloud data of the surface shape of the inner side wall of the hole into the linearized error equation to obtain a parameter adjustment quantity of the initial equation, adjusting the initial parameter according to the parameter adjustment quantity, and updating the initial equation; and iterating for a plurality of times until the iteration ending condition is met, outputting a current initial equation, and obtaining the coordinate relation of the first axis.

Optionally, in an embodiment of the present application, the determining, by data alignment, a first hole section and a first shaft section in the spatial three-dimensional shapes of the hole and the shaft, respectively, which have the highest similarity to the first shaft hole section, includes: for any section in the three-dimensional shape of the space, determining boundary distances between the curves of the holes and the shafts on the left side and the right side of the any section and the curves of the holes and the shafts in the section of the first shaft hole respectively based on a dynamic time normalization method; and respectively selecting the left and right boundary distances and the smallest cross section as the first hole cross section and the first shaft cross section.

Optionally, in an embodiment of the present application, the obtaining, by the coordinate relationship of the first axis, coordinates of a second axis corresponding to the first hole section and coordinates of a third axis corresponding to the first axis section, and calculating the inclination and coaxiality between the second axis and the third axis according to the coordinates of the second axis and the coordinates of the third axis, includes: obtaining hole axis projection and hole point projection of the second axis according to the coordinate relation of the first axis; obtaining an axial axis projection and an on-axis point projection of the third axis according to the coordinate relation of the first axis; calculating an included angle between the second axis and the third axis by using an included angle calculation formula according to the point projection on the hole and the point projection on the shaft, and obtaining the inclination between the second axis and the third axis according to the included angle; and calculating the axis distance of the axis thickness center between the second axis and the third axis by using an axis distance calculation formula according to the hole axis projection, the axis projection, the point projection on the hole and the point projection on the axis, and obtaining the coaxiality between the second axis and the third axis according to the axis distance of the axis thickness center.

An embodiment of a second aspect of the present application provides a device for detecting precision of shaft hole mounting pose, including: the fitting module is used for constructing the spatial three-dimensional shapes of the hole and the shaft by utilizing the pre-acquired point cloud data of the inner side wall surface shape of the hole assembled by the shaft hole and the point cloud data of the outer side wall surface shape of the shaft, and performing axis fitting on the spatial three-dimensional shapes of the hole and the shaft to obtain a first axis; the intercepting module is used for intercepting a section of the shaft hole after the shaft hole is assembled according to the space three-dimensional shapes of the hole and the shaft to obtain a first shaft hole section, and respectively determining a first hole section and a first shaft section which are highest in similarity with the first shaft hole section in the space three-dimensional shapes of the hole and the shaft through data alignment; the precision detection module is used for respectively obtaining the coordinate of the second axis corresponding to the first hole section and the coordinate of the third axis corresponding to the first hole section through the coordinate relation of the first axis, and calculating the inclination and coaxiality between the second axis and the third axis according to the coordinate of the second axis and the coordinate of the third axis so as to determine the shaft hole assembly pose precision of the shaft hole assembly.

Optionally, in one embodiment of the present application, the fitting module includes: the construction unit is used for constructing a cylindrical space three-dimensional shape according to the point cloud data of the inner side wall surface of the hole and the point cloud data of the outer side wall surface of the shaft when the side wall of the hole or the shaft assembled in the shaft hole is a cylindrical surface, and taking the cylindrical axis as the first axis; and the screening unit is used for screening the point cloud data with the side wall being the cylindrical surface from the point cloud data of the inner side wall surface of the hole and the point cloud data of the outer side wall surface of the shaft when the side wall of the hole or the shaft assembled in the shaft hole is the cylindrical surface, and constructing a cylindrical space three-dimensional shape according to the screened point cloud data, wherein the cylindrical axis is used as the first axis.

Optionally, in an embodiment of the present application, after the axis fitting the spatial three-dimensional shapes of the hole and the shaft to obtain the first axis, the method further includes: the parameter determining module is used for constructing an initial equation of the first axis in a shaft hole assembly coordinate system after performing axis fitting on the spatial three-dimensional shapes of the hole and the shaft to obtain the first axis, and determining initial parameters of the initial equation according to a fitting process; the solving module is used for constructing an error equation of the initial equation and solving the error equation by using a linearization least square method to obtain a linearized error equation; the adjustment module is used for bringing the point cloud data of the inner wall surface shape of the hole into the linearized error equation to obtain the parameter adjustment quantity of the initial equation, adjusting the initial parameter according to the parameter adjustment quantity and updating the initial equation; and the iteration module is used for iterating for a plurality of times until the iteration ending condition is met, outputting a current initial equation and obtaining the coordinate relation of the first axis.

Optionally, in one embodiment of the present application, the intercepting module includes: a distance determining unit, configured to determine, for any section in the three-dimensional spatial profile, boundary distances between a hole and shaft curve on the left and right sides of the any section and a hole and shaft curve in the first shaft hole section, respectively, based on a dynamic time alignment method; and the selecting unit is used for selecting the left and right boundary distances and the smallest cross section as the first hole cross section and the first shaft cross section respectively.

Optionally, in one embodiment of the present application, the precision detection module includes: the first projection unit is used for obtaining hole axis projection and point projection on the hole of the second axis according to the coordinate relation of the first axis; the second projection unit is used for obtaining the axial axis projection and the on-axial point projection of the third axis according to the coordinate relation of the first axis; the first calculation unit is used for calculating an included angle between the second axis and the third axis by using an included angle calculation formula according to the point projection on the hole and the point projection on the shaft, and obtaining the inclination between the second axis and the third axis according to the included angle; and the second calculation unit is used for calculating the axis distance of the axis thickness center between the second axis and the third axis according to the axis projection of the hole, the axis projection of the axis, the point projection on the hole and the point projection on the axis by using an axis distance calculation formula, and obtaining the coaxiality between the second axis and the third axis according to the axis distance of the axis thickness center.

An embodiment of a third aspect of the present application provides an electronic device, including: the device comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, wherein the processor executes the program to execute the shaft hole assembly pose precision detection method according to the embodiment.

An embodiment of the fourth aspect of the present application provides a computer-readable storage medium having stored thereon a computer program that is executed by a processor to perform the shaft hole mounting posture accuracy detection method as described in the above embodiment.

Therefore, the application has at least the following beneficial effects:

The method comprises the steps of constructing space three-dimensional shapes of a hole and a shaft by utilizing pre-acquired hole inner side wall surface shape point cloud data and shaft outer side wall surface shape point cloud data of shaft hole assembly, and performing axis fitting on the space three-dimensional shapes of the hole and the shaft to obtain a first axis; a first shaft hole section is obtained by cutting a section of the assembled shaft hole according to the space three-dimensional shapes of the hole and the shaft, and a first hole section and a first shaft section which have the highest similarity with the first shaft hole section in the space three-dimensional shapes of the hole and the shaft are respectively determined through data alignment; and respectively obtaining the coordinates of a second axis corresponding to the first hole section and the coordinates of a third axis corresponding to the first shaft section through the coordinate relation of the first axis, and calculating the inclination and coaxiality between the second axis and the third axis according to the coordinates of the second axis and the coordinates of the third axis so as to determine the shaft hole assembly pose precision of the shaft hole assembly. Thus, closely matched mating surface type data is accurately detected. Therefore, the problems of shaft hole assembly precision detection and the like are solved.

Additional aspects and advantages of the application 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 application.

Drawings

The foregoing and/or additional aspects and advantages of the application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a flow chart of a method for detecting shaft hole assembly pose accuracy according to an embodiment of the application;

fig. 2 is a schematic diagram of measurement space surface shape point cloud data of a contact three-coordinate measurement device according to an embodiment of the present application;

FIG. 3 is a schematic diagram of screening cylindrical surface areas from an overall point cloud according to one embodiment of the present application;

FIG. 4 is a schematic view of a spatial cylindrical surface fit provided in accordance with one embodiment of the present application;

FIG. 5 is a flow chart of a fitting spatial cylinder based on a nonlinear least squares method according to an embodiment of the present application;

FIG. 6 is a schematic diagram of execution logic of a method for detecting accuracy of shaft hole assembly pose according to an embodiment of the present application;

fig. 7 is an exemplary diagram of a detection device for shaft hole mounting pose accuracy according to an embodiment of the present application;

Fig. 8 is a schematic structural diagram of an electronic device according to an embodiment of the application.

Reference numerals illustrate: the device comprises a fitting module-100, an intercepting module-200, a precision detection module-300, a memory-801, a processor-802 and a communication interface-803.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present application and should not be construed as limiting the application.

The method, the device, the electronic equipment and the storage medium for detecting the axle hole assembly pose accuracy according to the embodiment of the application are described below with reference to the accompanying drawings. In order to solve the problems in the prior art, the application provides a detection method for shaft hole assembly pose precision, in the method, the detection method is used for detecting mating surface type data of close fit (the clearance is less than 5 microns). The assembly error is measured indirectly by cutting along a specific section after the assembled objects are fixed to each other. Specifically, constructing the spatial three-dimensional shapes of the hole and the shaft by utilizing the pre-acquired point cloud data of the inner side wall surface shape of the hole assembled by the shaft hole and the point cloud data of the outer side wall surface shape of the shaft, and performing axis fitting on the spatial three-dimensional shapes of the hole and the shaft to obtain a first axis; a first shaft hole section is obtained by cutting a section of the assembled shaft hole according to the space three-dimensional shapes of the hole and the shaft, and a first hole section and a first shaft section which have the highest similarity with the first shaft hole section in the space three-dimensional shapes of the hole and the shaft are respectively determined through data alignment; and respectively obtaining the coordinates of a second axis corresponding to the first hole section and the coordinates of a third axis corresponding to the first shaft section through the coordinate relation of the first axis, and calculating the inclination and coaxiality between the second axis and the third axis according to the coordinates of the second axis and the coordinates of the third axis so as to determine the shaft hole assembly pose precision of the shaft hole assembly. Thereby accurately detecting the mating surface type data of the close fit. Therefore, the problems of shaft hole assembly precision detection and the like are solved.

Specifically, fig. 1 is a flowchart of a method for detecting shaft hole assembly pose accuracy according to an embodiment of the present application.

As shown in fig. 1, the method for detecting the precision of the shaft hole assembly pose comprises the following steps:

In step S101, spatial three-dimensional shapes of the hole and the shaft are constructed by using the point cloud data of the inner wall surface of the hole assembled in the shaft hole and the point cloud data of the outer wall surface of the shaft acquired in advance, and the spatial three-dimensional shapes of the hole and the shaft are subjected to axis fitting to obtain a first axis.

It will be appreciated that the definition of the assembly accuracy depends on the axis of the bore and the shaft. For the detection task, it is necessary to find the axis of the hole and the shaft accurately. During production, the actual axis of the bore and shaft is not directly measured, and therefore it is necessary to estimate the axis of the object from its profile. Due to manufacturing errors, there is a certain difference in the actual shape of the hole and the shaft from the theoretical shape of the corresponding digital-to-analog. And such manufacturing errors tend to be random. Depending on the profile of the single section of the bore and shaft, the estimated axis is not accurate.

Therefore, the embodiment of the application adopts the contact type three-measuring machine to detect the complete space three-dimensional shape of the hole and the shaft, and the complete space three-dimensional shape of the hole and the shaft is relied on to fit the axis of the object, so that the axis estimation of the hole and the shaft is more accurate.

It should be noted that, in the embodiment of the present application, the assembly of the hole and the single shaft in the group of shafts is taken as an example, and the detection method of the shaft hole assembly pose accuracy is described in detail.

Optionally, in one embodiment of the present application, performing axis fitting on the spatial three-dimensional shape of the hole and the shaft to obtain a first axis includes: when the side wall of a hole or a shaft assembled in the shaft hole is a cylindrical surface, constructing a cylindrical space three-dimensional shape according to the point cloud data of the surface shape of the inner side wall of the hole and the point cloud data of the surface shape of the outer side wall of the shaft, and taking a cylindrical axis as a first axis; when the side wall of a hole or a part of the side wall of a shaft hole assembly is a cylindrical surface, screening the point cloud data with the side wall being the cylindrical surface from the point cloud data of the inner side wall surface of the hole and the point cloud data of the outer side wall surface of the shaft, constructing a cylindrical space three-dimensional shape according to the screened point cloud data, and taking a cylindrical axis as a first axis.

Specifically, on the basis of detecting the external surface type point cloud, the measured data are further fitted into a space cylinder, and the axis of the cylinder is obtained, namely the axis of the hole or the shaft. As shown in fig. 2, first, using a contact three-coordinate measuring apparatus, hole inner side wall surface shape point cloud data and shaft outer side wall surface shape point cloud data are obtained. The surface shape point cloud data of the inner side wall of the hole is recorded as

C＝{c_i|c_i＝(x_c,i,y_c,i,z_c,i),i＝1,2,K,m}

The surface shape point cloud data of the outer side wall surface of the shaft is recorded as

G＝{g_i|g_i＝(x_g,i,y_g,i,z_g,i),i＝1,2,K,n}

Then, based on the measured results, the actual axes of the hole and the shaft are fitted with reference to the theoretical digital-analog of the hole shaft.

Aiming at a hole or a shaft with a cylindrical side wall, the cylindrical axis can be directly fitted by using complete point cloud data without screening the point cloud data; aiming at a hole or a shaft with a main body part being a cylindrical surface and a small part being a non-cylindrical surface, the point cloud data corresponding to the cylindrical surface area needs to be screened out, and then the cylindrical axis is fitted by using the point cloud data corresponding to the cylindrical surface area.

Further, in the embodiment of the present application, the specific implementation manner of screening the cylindrical surface area from the whole point cloud is as follows:

Taking a hole as an example, as shown in fig. 3, each point C _i in the point cloud data C sequentially obtains a plurality of adjacent points, fits the adjacent points into a plane, and obtains a plane normal n _c,i. The normals corresponding to each point in the point cloud data obtained according to the method are approximately coplanar with each other. The normal n _c,ax to the approximate plane in which all of these normals lie is an approximation of the bore axis. All point clouds are projected to the floor along normal n _c,ax. In the bottom surface, the dot after projection is designated pc _i. All the projected point clouds are mostly distributed in a circular shape, and a small part is distributed in a straight line. And fitting all the point clouds projected to the bottom surface into a circle. The region with the largest fitting error appears at the point cloud distributed in a straight line, and the corresponding point with the largest fitting error is marked as pc _max. And taking pc _max as a center, solving a plurality of adjacent points to fit to straight lines on two sides, judging the distance d _i between all projected points pc _i and the straight lines, setting a threshold d _lim, and judging the boundary of a straight line area, so as to screen out all points pc _i distributed in a circular shape, and further screen out all points c _i distributed in a cylindrical shape.

Optionally, in an embodiment of the present application, after the axis fitting is performed on the spatial three-dimensional shapes of the hole and the shaft to obtain the first axis, the method further includes: constructing an initial equation of a first axis in a shaft hole assembly coordinate system, and determining initial parameters of the initial equation according to a fitting process; constructing an error equation of the initial equation, and solving the error equation by using a linearization least square method to obtain a linearized error equation; bringing the point cloud data of the surface shape of the inner side wall of the hole into a linearized error equation to obtain a parameter adjustment quantity of an initial equation, adjusting initial parameters according to the parameter adjustment quantity, and updating the initial equation; and iterating for a plurality of times until the iteration ending condition is met, outputting a current initial equation, and obtaining the coordinate relation of the first axis.

Specifically, in the embodiment of the present application, the manner of fitting the axis from the cylindrical surface region described above is as follows: as shown in figure 4 of the drawings,

The spatial cylinder is characterized by an equation with x ₀,y₀,z₀, r, l, m, n as parameters:

(x-x₀)²+(y-y₀)²+(z-z₀)²-r²＝[l(x-x₀)+m(y-y₀)+n(z-z₀)]²

Where x ₀,y₀,z₀ is the intersection point of the cylindrical axis and the bottom surface, r is the radius of the cylindrical section, (l, m, n), | (l, m, n) || ₂ =1 is the unit normal vector parallel to the cylindrical axis.

One specific implementation method for the parameters x ₀,y₀,z₀, r, l, m, n is the nonlinear least squares method. Taking a hole as an example, firstly, obtaining an approximate axis n _c,ax by combining a point cloud screening process, and determining initial values of parameters l, m and nSelecting the intersection point of the bottom surface obtained in the point cloud screening process and the approximate axis n _c,ax as the initial value of the parameter x ₀,y₀,z₀ Selecting the radius of all the point fitting circles projected to the bottom surface, which are obtained in the point cloud screening process, as the initial value of the parameter r

The construction error equation is as follows:

e(x,y,z)＝(x-x₀)²+(y-y₀)²+(z-z₀)²-r²-[l(x-x₀)+m(y-y₀)+n(z-z₀)]²

For least squares fitting, it is desirable that the fit residuals for all points c _i＝(x_c,i,y_c,i,z_c,i) be minimal. Since the error equation presents a nonlinear structural form to the parameters x ₀,y₀,z₀, r, l, m, n, an iterative linearization least square is used to solve the optimal parameters. As shown in fig. 5, note:

The error equation is linearized and then written as:

Wherein, the partial derivatives are respectively developed for the parameters x ₀,y₀,z₀, r, l, m and n. So far, the problem has been converted into a linear least squares problem. And taking all the screened points in the point set C into a linearized error equation at one time, and obtaining parameter adjustment amounts delta x ₀,Δy₀,Δz₀, delta r, delta l, delta m and delta n. The parameter adjustment amounts Deltax ₀,Δy₀,Δz₀, deltar, deltal, deltam, deltan are added to the parameter initial value And obtaining updated parameters.

And continuing to take the updated parameters as initial values, and repeating the linearization and least square processes until the parameter adjustment amounts delta x ₀,Δy₀,Δz₀, delta r, delta l, delta m and delta n are smaller than a certain threshold value, wherein the parameters x ₀,y₀,z₀, r, l, m and n are considered to be converged.

In step S102, a first shaft hole section is obtained by cutting a section of the assembled shaft hole according to the spatial three-dimensional shapes of the hole and the shaft, and a first hole section and a first shaft section with highest similarity with the first shaft hole section in the spatial three-dimensional shapes of the hole and the shaft are respectively determined through data alignment.

It will be appreciated that by detecting an external surface type point cloud, the measurement data is fitted to a spatial cylinder, thereby obtaining a fitted axis of the hole or shaft. However, since the definition of the fitting error depends on the relative positional relationship of the hole and the axis of the shaft, it is also necessary to separately detect the outer shapes of the hole and the shaft.

Since the hole and the shaft are in an assembled state and are in a contact or micro-gap state (micrometer level) with each other, a general non-contact type measurement method (industrial CT, ultrasonic detection, etc.) cannot accurately obtain the shape data of the required hole and shaft. Therefore, in the embodiment of the application, a more accurate detection mode is adopted, namely, the assembled shaft hole is filled and solidified by photosensitive resin and then is split, and the plane two-dimensional shape of the section inner hole and the shaft is measured by a high-power microscope (1000 times).

It should be noted that the holes and shaft surfaces are pre-coated with a photo-curable resin prior to assembly. After the assembly is performed, the resin is solidified by ultraviolet irradiation, and the fixed connection of the hole and the shaft is ensured. And (3) selecting a specific section as a section plane according to the detection result of the three-dimensional shape of the hole and the shaft space, and milling the assembled shaft hole into a section plane along the selected section plane. Thereby obtaining the first shaft hole section and the first shaft section.

Alternatively, in one embodiment of the present application, determining a first hole section and a first shaft section in the spatial three-dimensional shapes of the hole and the shaft, respectively, that have the highest similarity to the first shaft hole section by data alignment includes: for any section in the three-dimensional shape of the space, determining boundary distances between the curves of the holes and the shafts on the left side and the right side of the any section and the curves of the holes and the shafts in the section of the first shaft hole respectively based on a dynamic time normalization method; and respectively selecting the left and right boundary distances and the smallest cross section as a first hole cross section and a first shaft cross section.

Since the boundary between the hole and the axis can be detected at the same time under the microscope inspection screen after the assembly is completed. Due to the limitations of the microscope's field of view, it is often difficult to simultaneously space the left and right boundaries within the field of view. The boundaries of the hole and the shaft on the left and right sides of the cross-section will be measured separately.

In the coordinate system on one side, the boundary of the hole and the axis is defined. The boundary of the hole with the axis is in the form of a two-dimensional point cloud. The surface shape point cloud data of the inner side walls of the holes at the left side and the right side are recorded as follows:

The surface shape point cloud data of the outer side wall surface of the shaft at the left side and the right side are recorded as follows:

It is noted that the point cloud data on the left and right sides are independent of each other. The point cloud data The relative position relation is unknown, and the point cloud data is obtainedThe relative positional relationship is also unknown. But is provided withIn the same coordinate system, has a known mutual position relationship,In the same coordinate system, has a known mutual positional relationship.

Because the actual cutting plane deviates from the selected theoretical cutting plane, the theoretical cutting plane and the actual cutting plane are directly used for data alignment, and the estimation of the hole in the actual cutting plane and the axis of the shaft is inaccurate. Therefore, it is necessary to search for a section most similar to a planar two-dimensional shape corresponding to an actual section among three-dimensional shapes of a space by a certain search algorithm.

Specifically, in the embodiment of the present application, a specific implementation method of data alignment is as follows:

Taking a hole as an example, in the three-dimensional point cloud data C, taking an initial theoretical section as a center, searching a section which is most similar to an actual section within a certain angle range and a certain displacement range.

Further, a specific implementation method of similarity determination is based on a dynamic time warping (DYNAMIC TIME WARPING, DTW) method. In a section cf in a three-dimensional shape of a certain space, the surface shape point cloud data of the inner side walls of the holes at the left side and the right side are recorded as follows:

C^l＝{c^l _i|c^l _i＝(x^l _c,i,z^l _c,i),i＝1,2,K,p}

C^r＝{c^r _i|c^r _i＝(x^r _c,i,z^r _c,i),i＝1,2,K,q}

in the same section, the surface shape point cloud data of the shaft outer side wall surfaces at the left side and the right side are recorded as follows:

G^l＝{g^l _i|g^l _i＝(x^l _g,i,z^l _g,i),i＝1,2,K,r}

G^r＝{g^r _i|g^r _i＝(x^r _g,i,z^r _g,i),i＝1,2,K,s}

It is noted that the point cloud data of the hole and the shaft are independent of each other. The relative positional relationship of the point cloud data C ^l,G^l is unknown, and the relative positional relationship of the point cloud data C ^r,G^r is also unknown. However, C ^l,C^r is located in the same coordinate system, has a known mutual positional relationship, and G ^l,G^r is located in the same coordinate system, and has a known mutual positional relationship.

The detected amount includes a spatial three-dimensional shape of the hole and the shaft before assembly, and a planar two-dimensional shape of the hole and the shaft after assembly. By manually controlling the sectioned cross section, the correspondence between the planar two-dimensional shape in the cross section and the spatial three-dimensional shape of the hole and the shaft can be roughly determined, but is not accurate. Therefore, the more accurate data alignment method is to take the manual control section as a search center, and search the section which is the most similar to the planar two-dimensional shape corresponding to the actual section in the three-dimensional shape of the space in a certain angle and displacement variation range.

The data alignment process of the hole and the shaft is performed separately. A cross-section is selected within the search range of the spatial three-dimensional shape of the hole or axis. And respectively calculating the similarity between the boundaries of the left side hole and the right side hole or the axis of the cross section and the boundaries of the left side hole and the right side hole or the axis corresponding to the actual cross section. Taking a section with the highest total similarity of the left side and the right side as a section with the most similar planar two-dimensional appearance corresponding to the actual section.

Specifically, taking the alignment of the hole data as an example, one of the most suitable cross sections cf in the three-dimensional shape C of the hole space needs to be found, so that the point cloud data C ^l,C^r on the left and right sides are respectively matched with the actual measurement data on the left and right sidesMost similar. The distance between the two curves is judged by using a DTW mode, and the distances between the boundaries on the left side and the right side are respectively recorded as:

one of the most suitable cross-sections cf in the three-dimensional profile C of the hole space found satisfies:

Correspondingly, the surface shape point cloud data of the inner side wall surfaces of the holes on the left side and the right side in the cross section cf are recorded as In this plane, the hole axis (l, m, n) is projected asThe point on the hole (x ₀,y₀,z₀) is projected as

Likewise, using a similar approach, one can find an optimal cross-section gf in the spatial three-dimensional profile G of the axis. Correspondingly, the point cloud data of the outer side wall surface shape of the shaft on the left side and the right side in the cross section gf are recorded asIn this plane, the shaft axis (l, m, n) is projected asThe on-axis point (x ₀,y₀,z₀) is projected as

In step S103, the coordinates of the second axis corresponding to the first hole section and the coordinates of the third axis corresponding to the first hole section are obtained through the coordinate relationship of the first axis, and the inclination and coaxiality between the second axis and the third axis are calculated according to the coordinates of the second axis and the coordinates of the third axis, so as to determine the shaft hole assembly pose precision of the shaft hole assembly.

After the first hole section and the first shaft section are obtained, the data of the left side and the right side of the section inner hole and the shaft are respectively measured due to the limited visual field in the high magnification state, the measurement results are respectively positioned in two independent coordinate systems, and the mutual relation of the data of the left side and the right side is unknown. The definition of the assembly accuracy however depends on the axis of the bore and the shaft. In a planar section, the inclination and coaxiality between the axis of the hole and the shaft are shown. The two independent coordinate systems are converted to detect the accuracy of the assembly pose.

It will be appreciated that the planar two-dimensional shape obtained by the above search is optimally matched to the planar two-dimensional shape of the measured profile for the hole and axis, respectively. At this time, the axes of the planar two-dimensional shapes obtained by searching the respective spatial three-dimensional shapes of the hole and the shaft are the axes of the assembled hole and shaft. And further calculate the tilt error and the coaxial error of the two axes.

Optionally, in an embodiment of the present application, the obtaining, by the coordinate relationship of the first axis, the coordinates of the second axis corresponding to the first hole section and the coordinates of the third axis corresponding to the first axis section respectively, and calculating the inclination and coaxiality between the second axis and the third axis according to the coordinates of the second axis and the coordinates of the third axis includes: obtaining hole axis projection and hole upper point projection of the second axis according to the coordinate relation of the first axis; obtaining the axis projection and the on-axis point projection of the third axis according to the coordinate relation of the first axis; calculating an included angle between the second axis and the third axis by using an included angle calculation formula according to the point projection on the hole and the point projection on the shaft, and obtaining the inclination between the second axis and the third axis according to the included angle; and calculating the axis distance of the axis thickness center between the second axis and the third axis according to the hole axis projection, the axis projection, the point projection on the hole and the point projection on the axis by using an axis distance calculation formula, and obtaining the coaxiality between the second axis and the third axis according to the axis distance of the axis thickness center.

Specifically, in the embodiment of the present application, the mutual positions of the coordinate systems where the two planar point cloud data are located are defined as follows:

wherein, P and Q are two planar point cloud data, and d _x,d_z,θ_y is the translational and rotational relationship of two coordinate systems.

In the above-mentioned steps of the method,Is known, and therefore needs to be determined in order to restore the axisOr (b)Are the same, i.e Thereby determining the relative relation between the hole and the shaft fitting cylindrical surface under the same coordinate system, and further determining the relative relation between the hole and the shaft axis.

Is provided with

Wherein d_x ¹,d_z ¹,θ_y ¹,d_x ²,d_z ²,θ_y ²,d_x ³,d_z ³,θ_y ³ is the relative positional relationship between the point clouds to be determined.

Cloud the pointsThrough the known relative position relationship between the point clouds Relative positional relationship between point clouds to be determined Conversion toA coordinate system in which the object is located. The specific conversion method comprises the following steps:

In the formula, the function P is a translational rotation function of the point cloud, the first parameter is original data, and the second parameter is the relative position relation among the point clouds.

All point cloud transitions toAfter the coordinate system is located, an optimization problem is constructed, and d_x ¹,d_z ¹,θ_y ¹,d_x ²,d_z ²,θ_y ²,d_x ³,d_z ³,θ_y ³. optimization targets to be determined are solved as follows:

Due to Is the result of the measurement by the microscope,Is the detection result of the coordinate machine,Is less thanIs a point of (3). The nearest point search function c is used in the equation for sequential searchingMiddle ANDThe Euclidean distance of each point is the closest point.

Parameters d_x ¹,d_z ¹,θ_y ¹,d_x ²,d_z ²,θ_y ²,d_x ³,d_z ³,θ_y ³. can be obtained through nonlinear optimization, and after the assembly, the plane two dimensions of the left side and the right side of the hole and the shaft are registered with the space three-dimensional data. At this time, the liquid crystal display device,It can be considered that the hole is bordered on the left and right sides of the shaft after assembly. The plane sf is the projection of the central hole axisProjection onto the spot on the holePlane gf center axis projectionProjection from an on-axis pointTogether switch toA coordinate system in which the object is located. The axis of the converted hole is noted asThe hole point projection is recorded asThe axis of the converted shaft is noted asThe axial point projection is recorded as

The assembly errors of the application can be based onThe specific implementation method is as follows:

Axis tilt error is defined as the angle between two axes:

Axis tilt coaxial error is defined as the axis spacing of the shaft thickness centers:

Where l is the thickness of the shaft.

The method for detecting the accuracy of the mounting pose of the shaft hole will be described below with reference to the accompanying drawings. Fig. 6 is a schematic execution logic diagram of a method for detecting shaft hole assembly pose accuracy according to an embodiment of the present application. The specific execution logic is as follows:

S1: hole and shaft space three-dimensional shape detection and shaft center fitting:

the complete spatial three-dimensional shape of the hole and the shaft is detected by a contact three-measuring machine, and the complete spatial three-dimensional shape of the hole and the shaft is relied on to fit the axis of the object. On the basis of detecting the external surface type point cloud, the measured data are further fitted into a space cylinder, and the axis of the cylinder is obtained and is regarded as the axis of the hole or the shaft.

S2: hole and shaft assembly, curing and sectioning:

the hole and the shaft surface are pre-coated with a photo-curable resin prior to assembly. After the assembly is performed, the resin is solidified by ultraviolet irradiation, and the fixed connection of the hole and the shaft is ensured. And (3) selecting a specific section as a section plane according to the detection result of the three-dimensional shape of the hole and the shaft space, and milling the assembled shaft hole into a section plane along the selected section plane.

S3: and (3) detecting the two-dimensional shape of the hole and the axial plane in the section:

And (3) filling the assembled shaft hole with photosensitive resin, curing, cutting, and measuring the plane two-dimensional shape of the section inner hole and the shaft by a high-power microscope (1000 times). Because the visual field is limited in the high magnification state, the data of the left side and the right side of the cross section inner hole and the shaft are respectively measured, the measurement results are respectively positioned in two independent coordinate systems, and the mutual relation between the data of the left side and the data of the right side is unknown.

S4: the plane two-dimensional profile in the section is aligned with the spatial three-dimensional profile data:

And taking the manual control section as a search center, and searching a section which is the most similar to a planar two-dimensional shape corresponding to the actual section in the three-dimensional shape of the space within a certain angle and displacement change range. The data alignment process of the hole and the shaft is performed separately. Taking the hole as an example, a section is selected in the search range of the spatial three-dimensional shape of the hole. And respectively calculating the similarity between the hole boundaries at the left and right sides of the cross section and the hole boundaries at the left and right sides corresponding to the actual cross section. Taking a section with the highest total similarity of the left side and the right side as a section with the most similar planar two-dimensional appearance corresponding to the actual section.

S5: and (3) recovering and assembling accuracy detection of the profile inner hole and the shaft axis:

at this time, the axes of the planar two-dimensional shapes obtained by searching the respective spatial three-dimensional shapes of the hole and the shaft are the axes of the assembled hole and shaft. And further calculate the tilt error and the coaxial error of the two axes.

According to the detection method for the axle hole assembly pose accuracy, which is provided by the embodiment of the application, the spatial three-dimensional shapes of the hole and the axle are constructed by utilizing the pre-acquired point cloud data of the inner side wall surface shape of the axle hole assembly and the point cloud data of the outer side wall surface shape of the axle, and the spatial three-dimensional shapes of the hole and the axle are subjected to axis fitting to obtain a first axis; a first shaft hole section is obtained by cutting a section of the assembled shaft hole according to the space three-dimensional shapes of the hole and the shaft, and a first hole section and a first shaft section which have the highest similarity with the first shaft hole section in the space three-dimensional shapes of the hole and the shaft are respectively determined through data alignment; and respectively obtaining the coordinates of a second axis corresponding to the first hole section and the coordinates of a third axis corresponding to the first shaft section through the coordinate relation of the first axis, and calculating the inclination and coaxiality between the second axis and the third axis according to the coordinates of the second axis and the coordinates of the third axis so as to determine the shaft hole assembly pose precision of the shaft hole assembly. Thus, closely matched mating surface type data is accurately detected.

Next, a detection device for shaft hole assembly pose accuracy according to an embodiment of the present application is described with reference to the accompanying drawings.

Fig. 7 is a block diagram of a device for detecting shaft hole mounting pose accuracy according to an embodiment of the present application.

As shown in fig. 7, the shaft hole mounting posture accuracy detection device 10 includes: fitting module 100, clipping module 200, and accuracy detection module 300.

The fitting module 100 is configured to construct a spatial three-dimensional shape of the hole and the shaft by using the pre-acquired point cloud data of the inner side wall surface shape of the hole and the point cloud data of the outer side wall surface shape of the shaft hole assembled in advance, and perform axis fitting on the spatial three-dimensional shape of the hole and the shaft to obtain a first axis; the intercepting module is used for intercepting a section of the first shaft hole according to the space three-dimensional shape of the hole and the shaft after the shaft hole is assembled to obtain a section of the first shaft hole, and respectively determining a section of the first hole and a section of the first shaft with the highest similarity with the section of the first shaft hole in the space three-dimensional shape of the hole and the shaft through data alignment; the precision detection module 300 is configured to obtain, through a coordinate relationship of the first axis, a coordinate of a second axis corresponding to the first hole section and a coordinate of a third axis corresponding to the first axis section, and calculate, according to the coordinate of the second axis and the coordinate of the third axis, an inclination and coaxiality between the second axis and the third axis, so as to determine an axle hole assembly pose precision of the axle hole assembly.

Alternatively, in one embodiment of the present application, the fitting module 100 includes: the construction unit is used for constructing a cylindrical space three-dimensional shape according to the point cloud data of the inner side wall surface of the hole and the point cloud data of the outer side wall surface of the shaft when the side wall of the hole or the shaft assembled in the shaft hole is a cylindrical surface, and taking a cylindrical axis as a first axis; and the screening unit is used for screening the point cloud data with the side wall being the cylindrical surface from the point cloud data of the inner side wall surface of the hole and the point cloud data of the outer side wall surface of the shaft when the side wall of the hole or the part of the shaft assembled in the shaft hole is the cylindrical surface, constructing a cylindrical space three-dimensional shape according to the screened point cloud data, and taking the cylindrical axis as a first axis.

Optionally, in an embodiment of the present application, after the axis fitting is performed on the spatial three-dimensional shapes of the hole and the shaft to obtain the first axis, the method further includes: the parameter determining module is used for constructing an initial equation of the first axis in the shaft hole assembly coordinate system after the axis fitting is carried out on the spatial three-dimensional shapes of the hole and the shaft to obtain the first axis, and determining initial parameters of the initial equation according to the fitting process; the solving module is used for constructing an error equation of the initial equation and solving the error equation by using a linearization least square method to obtain a linearized error equation; the adjustment module is used for bringing the point cloud data of the surface shape of the inner side wall of the hole into a linearized error equation to obtain a parameter adjustment quantity of an initial equation, adjusting the initial parameter according to the parameter adjustment quantity, and updating the initial equation; and the iteration module is used for iterating for a plurality of times until the iteration ending condition is met, outputting a current initial equation and obtaining the coordinate relation of the first axis.

Optionally, in one embodiment of the present application, the interception module 200 includes: the distance determining unit is used for determining boundary distances between the curves of the holes and the shafts on the left side and the right side of any section and the curves of the holes and the shafts in the section of the first shaft hole respectively for any section in the three-dimensional shape of the space based on a dynamic time sorting method; and the selecting unit is used for respectively selecting the left and right boundary distances and the smallest cross section as a first hole cross section and a first shaft cross section.

Optionally, in one embodiment of the present application, the precision detection module 300 includes: the first projection unit is used for obtaining hole axis projection and point projection on the hole of the second axis according to the coordinate relation of the first axis; the second projection unit is used for obtaining the axial line projection and the on-axis point projection of the third axis according to the coordinate relation of the first axis; the first calculation unit is used for calculating an included angle between the second axis and the third axis according to the point projection on the hole and the point projection on the shaft by using an included angle calculation formula, and obtaining the inclination between the second axis and the third axis according to the included angle; and the second calculation unit is used for calculating the axis distance of the axis thickness center between the second axis and the third axis according to the hole axis projection, the axis projection, the point projection on the hole and the point projection on the axis by using an axis distance calculation formula, and obtaining the coaxiality between the second axis and the third axis according to the axis distance of the axis thickness center.

It should be noted that, the explanation of the foregoing embodiment of the method for detecting the precision of the shaft hole assembly pose is also applicable to the device for detecting the precision of the shaft hole assembly pose in this embodiment, and will not be repeated here.

According to the detection device for the axle hole assembly pose precision provided by the embodiment of the application, firstly, the space three-dimensional shape detection and axle center fitting are carried out on the axle and the axle; thereafter, the hole and the shaft surface are pre-coated with a photo-curable resin before assembly. After the assembly is performed, the resin is solidified by ultraviolet irradiation, and the fixed connection of the hole and the shaft is ensured. Selecting a specific section as a section plane according to the three-dimensional shape detection result of the hole and shaft space, and milling a section plane of the assembled shaft hole along the selected section plane; detecting the plane two-dimensional shape of the hole and the shaft in the section; and finally, recovering the inner hole of the section and the axis of the shaft, and detecting the assembly accuracy. Thus, closely matched mating surface type data is accurately detected.

Fig. 8 is a schematic structural diagram of an electronic device according to an embodiment of the present application. The electronic device may include:

a memory 801, a processor 802, and a computer program stored on the memory 801 and executable on the processor 802.

The processor 802 implements the method for detecting the shaft hole mounting pose accuracy provided in the above-described embodiment when executing a program.

Further, the electronic device further includes:

a communication interface 803 for communication between the memory 801 and the processor 802.

A memory 801 for storing a computer program executable on the processor 802.

The memory 801 may include high-speed RAM memory or may further include non-volatile memory (non-volatile memory), such as at least one magnetic disk memory.

If the memory 801, the processor 802, and the communication interface 803 are implemented independently, the communication interface 803, the memory 801, and the processor 802 may be connected to each other through a bus and perform communication with each other. The bus may be an industry standard architecture (Industry Standard Architecture, abbreviated ISA) bus, an external device interconnect (PERIPHERAL COMPONENT, abbreviated PCI) bus, or an extended industry standard architecture (Extended Industry Standard Architecture, abbreviated EISA) bus, among others. The buses may be divided into address buses, data buses, control buses, etc. For ease of illustration, only one thick line is shown in fig. 8, but not only one bus or one type of bus.

Alternatively, in a specific implementation, if the memory 801, the processor 802, and the communication interface 803 are integrated on a chip, the memory 801, the processor 802, and the communication interface 803 may communicate with each other through internal interfaces.

The processor 802 may be a central processing unit (Central Processing Unit, abbreviated as CPU), or an Application SPECIFIC INTEGRATED Circuit, abbreviated as ASIC, or one or more integrated circuits configured to implement embodiments of the present application.

The present embodiment also provides a computer-readable storage medium having stored thereon a computer program, characterized in that the program, when executed by a processor, implements the shaft hole mounting pose accuracy detection method as described above.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or N embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, "N" means at least two, for example, two, three, etc., unless specifically defined otherwise.

Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more N executable instructions for implementing specific logical functions or steps of the process, and further implementations are included within the scope of the preferred embodiment of the present application in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the embodiments of the present application.

It is to be understood that portions of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, the N steps or methods may be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. As with the other embodiments, if implemented in hardware, may be implemented using any one or combination of the following techniques, as is well known in the art: discrete logic circuits having logic gates for implementing logic functions on data signals, application specific integrated circuits having suitable combinational logic gates, programmable Gate Arrays (PGAs), field Programmable Gate Arrays (FPGAs), and the like.

Those of ordinary skill in the art will appreciate that all or a portion of the steps carried out in the method of the above-described embodiments may be implemented by a program to instruct related hardware, where the program may be stored in a computer readable storage medium, and where the program, when executed, includes one or a combination of the steps of the method embodiments.

Claims

1. The detection method for the axle hole assembly pose precision is characterized by comprising the following steps of:

constructing a space three-dimensional shape of a hole and a shaft by utilizing pre-acquired hole inner side wall surface shape point cloud data and shaft outer side wall surface shape point cloud data of the shaft hole assembly, and performing axis fitting on the space three-dimensional shape of the hole and the shaft to obtain a first axis;

a first shaft hole section is obtained by cutting a section of the assembled shaft hole according to the space three-dimensional shapes of the hole and the shaft, and a first hole section and a first shaft section with highest similarity with the first shaft hole section in the space three-dimensional shapes of the hole and the shaft are respectively determined through data alignment;

The coordinate relationship of the first axis is used for respectively obtaining the coordinate of a second axis corresponding to the first hole section and the coordinate of a third axis corresponding to the first shaft section, and the inclination and coaxiality between the second axis and the third axis are calculated according to the coordinate of the second axis and the coordinate of the third axis so as to determine the shaft hole assembly pose precision of the shaft hole assembly;

The axis fitting of the spatial three-dimensional shape of the hole and the shaft to obtain a first axis comprises:

When the side wall of a hole or a shaft assembled in the shaft hole is a cylindrical surface, constructing a cylindrical space three-dimensional shape according to the point cloud data of the surface shape of the inner side wall of the hole and the point cloud data of the surface shape of the outer side wall of the shaft, and taking the cylindrical axis as the first axis;

When a part of the side wall of a hole or a shaft assembled in the shaft hole is a cylindrical surface, screening point cloud data with the side wall being the cylindrical surface from the point cloud data of the surface shape of the inner side wall of the hole and the point cloud data of the surface shape of the outer side wall of the shaft, constructing a cylindrical space three-dimensional shape according to the screened point cloud data, and taking the cylindrical axis as the first axis;

After the axis fitting is performed on the spatial three-dimensional shapes of the hole and the shaft to obtain a first axis, the method further comprises the following steps:

constructing an initial equation of the first axis in a shaft hole assembly coordinate system, and determining initial parameters of the initial equation according to a fitting process;

Constructing an error equation of the initial equation, and solving the error equation by using a linearization least square method to obtain a linearized error equation;

Bringing the point cloud data of the surface shape of the inner side wall of the hole into the linearized error equation to obtain a parameter adjustment quantity of the initial equation, adjusting the initial parameter according to the parameter adjustment quantity, and updating the initial equation;

iterating for a plurality of times until the iteration ending condition is met, outputting a current initial equation, and obtaining the coordinate relation of the first axis;

The determining, by data alignment, a first hole section and a first shaft section in the spatial three-dimensional shapes of the hole and the shaft, respectively, the first hole section and the first shaft section having the highest similarity with the first shaft section, includes:

For any section in the three-dimensional shape of the space, determining boundary distances between the curves of the holes and the shafts on the left side and the right side of the any section and the curves of the holes and the shafts in the section of the first shaft hole respectively based on a dynamic time normalization method;

Respectively selecting the left and right boundary distances and the smallest cross section as the first hole cross section and the first shaft cross section;

the step of obtaining the coordinates of the second axis corresponding to the first hole section and the coordinates of the third axis corresponding to the first axis section through the coordinate relation of the first axis, and calculating the inclination and coaxiality between the second axis and the third axis according to the coordinates of the second axis and the coordinates of the third axis, includes:

obtaining hole axis projection and hole point projection of the second axis according to the coordinate relation of the first axis;

obtaining an axial axis projection and an on-axis point projection of the third axis according to the coordinate relation of the first axis;

Calculating an included angle between the second axis and the third axis by using an included angle calculation formula according to the point projection on the hole and the point projection on the shaft, and obtaining the inclination between the second axis and the third axis according to the included angle;

And calculating the axis distance of the axis thickness center between the second axis and the third axis by using an axis distance calculation formula according to the hole axis projection, the axis projection, the point projection on the hole and the point projection on the axis, and obtaining the coaxiality between the second axis and the third axis according to the axis distance of the axis thickness center.

2. The utility model provides a detection device of shaft hole dress gesture precision which characterized in that includes:

The fitting module is used for constructing the spatial three-dimensional shapes of the hole and the shaft by utilizing the pre-acquired point cloud data of the inner side wall surface shape of the hole assembled by the shaft hole and the point cloud data of the outer side wall surface shape of the shaft, and performing axis fitting on the spatial three-dimensional shapes of the hole and the shaft to obtain a first axis;

The intercepting module is used for intercepting a section of the shaft hole after the shaft hole is assembled according to the space three-dimensional shapes of the hole and the shaft to obtain a first shaft hole section, and respectively determining a first hole section and a first shaft section which are highest in similarity with the first shaft hole section in the space three-dimensional shapes of the hole and the shaft through data alignment;

The precision detection module is used for respectively obtaining the coordinate of a second axis corresponding to the first hole section and the coordinate of a third axis corresponding to the first hole section through the coordinate relation of the first axis, and calculating the inclination and coaxiality between the second axis and the third axis according to the coordinate of the second axis and the coordinate of the third axis so as to determine the shaft hole assembly pose precision of the shaft hole assembly;

the fitting module comprises:

The construction unit is used for constructing a cylindrical space three-dimensional shape according to the point cloud data of the inner side wall surface of the hole and the point cloud data of the outer side wall surface of the shaft when the side wall of the hole or the shaft assembled in the shaft hole is a cylindrical surface, and taking the cylindrical axis as the first axis;

The screening unit is used for screening the point cloud data with the side wall being the cylindrical surface from the point cloud data of the inner side wall surface of the hole and the point cloud data of the outer side wall surface of the shaft when the side wall of the hole or the shaft assembled in the shaft hole is the cylindrical surface, constructing a cylindrical space three-dimensional shape according to the screened point cloud data, and taking the cylindrical axis as the first axis;

The parameter determining module is used for constructing an initial equation of the first axis in a shaft hole assembly coordinate system after performing axis fitting on the spatial three-dimensional shapes of the hole and the shaft to obtain the first axis, and determining initial parameters of the initial equation according to a fitting process;

The solving module is used for constructing an error equation of the initial equation and solving the error equation by using a linearization least square method to obtain a linearized error equation;

the adjustment module is used for bringing the point cloud data of the inner wall surface shape of the hole into the linearized error equation to obtain the parameter adjustment quantity of the initial equation, adjusting the initial parameter according to the parameter adjustment quantity and updating the initial equation;

The iteration module is used for iterating for a plurality of times until the iteration ending condition is met, outputting a current initial equation, and obtaining the coordinate relation of the first axis;

the intercepting module comprises:

A distance determining unit, configured to determine, for any section in the three-dimensional spatial profile, boundary distances between a hole and shaft curve on the left and right sides of the any section and a hole and shaft curve in the first shaft hole section, respectively, based on a dynamic time alignment method;

A selecting unit for selecting the left and right boundary distances and the smallest cross section as the first hole cross section and the first shaft cross section, respectively;

the precision detection module comprises:

The first projection unit is used for obtaining hole axis projection and point projection on the hole of the second axis according to the coordinate relation of the first axis;

the second projection unit is used for obtaining the axial axis projection and the on-axial point projection of the third axis according to the coordinate relation of the first axis;

The first calculation unit is used for calculating an included angle between the second axis and the third axis by using an included angle calculation formula according to the point projection on the hole and the point projection on the shaft, and obtaining the inclination between the second axis and the third axis according to the included angle;

and the second calculation unit is used for calculating the axis distance of the axis thickness center between the second axis and the third axis according to the axis projection of the hole, the axis projection of the axis, the point projection on the hole and the point projection on the axis by using an axis distance calculation formula, and obtaining the coaxiality between the second axis and the third axis according to the axis distance of the axis thickness center.

3. An electronic device, comprising: the device comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, wherein the processor executes the program to realize the detection method of the axle hole assembly pose precision according to claim 1.

4. A computer-readable storage medium having stored thereon a computer program, characterized in that the program is executed by a processor for realizing the shaft hole mounting pose accuracy detection method according to claim 1.