CN114782315A - Method, device, equipment and storage medium for detecting the accuracy of position and orientation of shaft hole assembly - Google Patents

Abstract

The application discloses a method and a device for detecting the accuracy of an axis hole assembly pose, electronic equipment and a storage medium, wherein the method comprises the following steps: firstly, carrying out spatial three-dimensional appearance detection and axis fitting on a hole and an axis; thereafter, before assembly, the hole and the shaft surface are coated with a light-curing resin in advance. After the assembly is carried out, the resin is cured through the irradiation of ultraviolet rays, and the fixed connection between the hole and the shaft is ensured. Selecting a specific section as a section according to the detection result of the three-dimensional appearance of the hole and the shaft space, and milling the assembled shaft hole into a section along the selected section; carrying out plane two-dimensional appearance detection on the holes and the shafts in the section; and aligning the two-dimensional shape of the plane in the section with the three-dimensional shape data of the space, finally, recovering the inner hole of the section and the axis of the shaft, and detecting the assembly precision. Thus, the fitting surface type data of the close fitting is accurately detected. Therefore, the problems of shaft hole assembly precision detection and the like are solved.

Description

Method, device, equipment and storage medium for detecting the accuracy of position and orientation of shaft hole assembly

technical field

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

Background technique

Shaft hole assembly is the most common form of assembly in industrial products. For high-precision shaft-hole assembly tasks, in the assembly process, it is necessary to strictly ensure the axis coaxiality and axis inclination between the shaft and the hole.

In the related art, the contact type detection method (probe type CMM) can accurately detect the external surface type data of the object, but cannot detect the mating surface type data after the assembly is completed; the non-contact type detection method (such as industrial CT, Ultrasound), cannot accurately detect the mating surface data of tight fit (gap <5 microns), which needs to be solved urgently.

SUMMARY OF THE INVENTION

The present application provides a method, device, electronic device and storage medium for detecting the position and orientation accuracy of shaft hole assembly, so as to solve the problems of shaft hole assembly accuracy detection and the like.

An embodiment of the first aspect of the present application provides a method for detecting the position and orientation accuracy of a shaft hole assembly, comprising the following steps: constructing a hole and The spatial three-dimensional shape of the shaft is obtained by performing axis fitting on the spatial three-dimensional shape of the hole and the shaft to obtain the first axis; according to the spatial three-dimensional shape of the hole and the shaft, a section plane after the assembly of the shaft hole is cut to obtain the first shaft. The hole section, the first hole section and the first shaft section with the highest similarity to the first shaft hole section in the spatial three-dimensional shape of the hole and the shaft are determined respectively through data alignment; through 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 shaft section are obtained respectively, and the second axis is calculated according to the coordinates of the second axis and the coordinates of the third axis The inclination and coaxiality between the third axis and the third axis are used to determine the position and orientation accuracy of the shaft hole assembly of the shaft hole assembly.

Optionally, in an embodiment of the present application, the first axis is obtained by performing axis fitting on the spatial three-dimensional shape of the hole and the shaft, including: the side wall of the hole or shaft assembled in the shaft hole is: In the case of a cylindrical surface, a cylindrical spatial three-dimensional shape is constructed according to the surface point cloud data of the inner side wall of the hole and the surface point cloud data of the outer side wall of the shaft, and the axis of the cylinder is used as the first axis; When part of the side wall of the hole or shaft assembled by the shaft hole is a cylindrical surface, the point cloud data of the side wall being a cylindrical surface are selected from the surface point cloud data of the inner side wall of the hole and the surface point cloud data of the outer side wall of the shaft. A cylindrical spatial three-dimensional shape is constructed according to the filtered point cloud data, and the cylindrical axis is used as the first axis.

Optionally, in an embodiment of the present application, after the first axis is obtained by performing axis fitting on the spatial three-dimensional shape of the hole and the shaft, the method further includes: constructing the first axis in a shaft hole assembly coordinate system The initial equation of the axis, the initial parameters of the initial equation are determined according to the fitting process; the error equation of the initial equation is constructed, and the linearized least squares method is used to solve the error equation to obtain a linearized error equation; The inner side wall surface point cloud data is brought into the linearized error equation to obtain the parameter adjustment amount of the initial equation, the initial parameter is adjusted according to the parameter adjustment amount, and the initial equation is updated; When the iteration end condition is satisfied, the current initial equation is output, and the coordinate relationship of the first axis is obtained.

Optionally, in an embodiment of the present application, the first hole section and the first hole section with the highest similarity to the first shaft hole section in the spatial three-dimensional shapes of the hole and the shaft are respectively determined through data alignment. Axial section, including: for any section in the three-dimensional shape of the space, the curve of the hole and the axis on the left and right sides of the any section and the curve of the hole in the first axis hole section are respectively determined based on the method of dynamic time normalization. The boundary distance between the hole and the shaft curve; the left and right boundary distances and the smallest section are respectively selected as the first hole section and the first shaft section.

Optionally, in an embodiment of the present application, the coordinates of the second axis corresponding to the first hole section and the third axis corresponding to the first axis section are obtained respectively through the coordinate relationship of the first axis. Coordinates of the axis, calculating the inclination and coaxiality between the second axis and the third axis according to the coordinates of the second axis and the third axis, including: obtaining according to the coordinate relationship of the first axis The hole axis projection and the point projection on the hole of the second axis; according to the coordinate relationship of the first axis, the axis axis projection and the point projection on the axis of the third axis are obtained; according to the point projection on the hole and the point projection The on-axis point projection uses the angle calculation formula to calculate the angle between the second axis and the third axis, and obtains the inclination between the second axis and the third axis according to the angle; The projection of the hole axis, the projection of the shaft axis, the projection of the point on the hole and the projection of the point on the shaft are used to calculate the axis distance of the shaft thickness center between the second axis and the third axis by using the axis distance calculation formula, according to The axis spacing of the center of the shaft thickness results in the coaxiality between the second axis and the third axis.

The embodiment of the second aspect of the present application provides a detection device for the position and orientation accuracy of the shaft hole assembly, including: a fitting module for using the pre-collected surface point cloud data of the inner side wall of the hole and the surface point cloud of the outer side wall of the shaft hole assembly. The data constructs the spatial three-dimensional shape of the hole and the shaft, and performs axis fitting on the spatial three-dimensional shape of the hole and the shaft to obtain the first axis; the interception module is used to intercept the shaft hole assembly according to the spatial three-dimensional shape of the hole and the shaft. The first shaft hole section is obtained from the last section, and the first hole section and the first shaft section with the highest similarity to the first shaft hole section in the spatial three-dimensional shapes of the hole and the shaft are determined through data alignment; An accuracy detection module, configured to obtain 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 relationship of the first axis, respectively, according to the second axis The coordinates of the axis and the coordinates of the third axis are used to calculate the inclination and coaxiality between the second axis and the third axis, so as to determine the accuracy of the shaft hole assembly position and orientation of the shaft hole assembly.

Optionally, in an embodiment of the present application, the fitting module includes: a construction unit for, when the side wall of the hole or the shaft to which the shaft hole is assembled is a cylindrical surface, according to the inner side wall surface of the hole The shape point cloud data and the surface shape point cloud data of the outer side wall of the shaft construct a cylindrical three-dimensional shape in space, and the axis of the cylinder is used as the first axis; the screening unit is used for the hole assembled in the shaft hole Or when part of the side wall of the shaft is a cylindrical surface, the point cloud data whose side wall is a cylindrical surface are filtered from the surface point cloud data of the inner side wall of the hole and the surface point cloud data of the outer side wall of the shaft, and the point cloud data of which the side wall is a cylindrical surface are selected according to the selected points. The cloud data constructs a cylindrical three-dimensional shape in space, and the cylindrical axis is used as the first axis.

Optionally, in an embodiment of the present application, after the first axis is obtained by performing axis fitting on the spatial three-dimensional contours of the hole and the shaft, the method further includes: a parameter determination module, used for adjusting the hole and the shaft. After the first axis is obtained by the axis fitting of the three-dimensional shape of the space, the initial equation of the first axis is constructed in the shaft hole assembly coordinate system, and the initial parameters of the initial equation are determined according to the fitting process; For the error equation of the initial equation, the linearized least squares method is used to solve the error equation to obtain a linearized error equation; an adjustment module is used to bring the surface point cloud data of the inner side wall of the hole into the linearized error equation, the parameter adjustment amount of the initial equation is obtained, the initial parameter is adjusted according to the parameter adjustment amount, and the initial equation is updated; the iterative module is used to iterate multiple times until the iteration end condition is met, and output the current initial equation , to obtain the coordinate relationship of the first axis.

Optionally, in an embodiment of the present application, the interception module includes: a distance determination unit, configured to determine, for any section in the three-dimensional shape of the space, respectively, based on a dynamic time normalization method. The boundary distance between the curve of the hole and the shaft on the left and right sides of a section and the curve of the hole and the shaft in the first shaft hole section; the selection unit is used to select the boundary distance and the smallest section on the left and right as the first A bore section and the first shaft section.

Optionally, in an embodiment of the present application, the precision detection module includes: a first projection unit, configured to obtain the hole axis projection of the second axis and the hole on the hole according to the coordinate relationship of the first axis point projection; a second projection unit for obtaining the axis axis projection and on-axis point projection of the third axis according to the coordinate relationship of the first axis; a first calculation unit for obtaining the point projection and on-axis point projection of the third axis according to the The on-axis point projection calculates the angle between the second axis and the third axis by using the angle calculation formula, and obtains the inclination between the second axis and the third axis according to the angle; 2. A calculation unit, configured to calculate the distance between the second axis and the third axis according to the hole axis projection, the axis axis projection, the point projection on the hole and the point projection on the axis by using the axis distance calculation formula The axial spacing of the center of the thickness of the shaft is obtained, and the coaxiality between the second axis and the third axis is obtained according to the axial spacing of the center of the thickness of the shaft.

An embodiment of a third aspect of the present application provides an electronic device, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor executes the program to execute The method for detecting the accuracy of the assembly position and orientation of the shaft hole as described in the above embodiments.

Embodiments of the fourth aspect of the present application provide a computer-readable storage medium on which a computer program is stored, and the program is executed by a processor to execute the method for detecting the position and orientation accuracy of an assembly of a shaft hole as described in the foregoing embodiments.

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

In this application, the spatial three-dimensional shape of the hole and the shaft is constructed by using the surface shape point cloud data of the inner side wall of the hole and the surface shape point cloud data of the outer side wall of the shaft assembled in advance, and the first three-dimensional shape of the hole and the shaft is obtained by axis fitting. Axis; according to the spatial three-dimensional shape of the hole and the shaft, take a section plane after the shaft hole is assembled to obtain the first shaft hole section, and determine the one with the highest similarity to the first shaft hole section in the spatial three-dimensional shape of the hole and the shaft through data alignment. The first hole section and the first shaft section; the coordinates of the second axis corresponding to the first hole section and the coordinates of the third axis corresponding to the first shaft section are obtained respectively through the coordinate relationship of the first axis, according to the coordinates of the second axis and The coordinates of the third axis are calculated by calculating the inclination and coaxiality between the second axis and the third axis, so as to determine the accuracy of the shaft hole assembly pose of the shaft hole assembly. Thereby, the closely fitting mating surface profile data can be accurately detected. As a result, problems such as detection of the assembly accuracy of the shaft hole are solved.

Additional aspects and advantages of the present application will be set forth, in part, in the following description, and in part will be apparent from the following description, or learned by practice of the present application.

Description of drawings

The above and/or additional aspects and advantages of the present application will become apparent and readily understood from the following description of embodiments taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a flowchart of a method for detecting the position and orientation accuracy of a shaft hole assembly provided according to an embodiment of the present application;

FIG. 2 is a schematic diagram of measuring spatial surface point cloud data provided by a contact type three-coordinate measuring device according to an embodiment of the present application;

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

4 is a schematic diagram of fitting a space cylindrical surface provided according to an embodiment of the present application;

5 is a flowchart of fitting a space cylinder based on a nonlinear least squares method provided according to an embodiment of the present application;

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

FIG. 7 is an exemplary diagram of a detection device for the accuracy of the assembly position and orientation of a shaft hole according to an embodiment of the present application;

FIG. 8 is a schematic structural diagram of an electronic device provided by an embodiment of the application.

Reference numeral description: fitting module-100, interception module-200, precision detection module-300, memory-801, processor-802, communication interface-803.

Detailed ways

The following describes in detail the embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, and are intended to be used to explain the present application, but should not be construed as a limitation to the present application.

The following describes the method, device, electronic device, and storage medium for detecting the position and orientation accuracy of the shaft hole assembly according to the embodiments of the present application with reference to the accompanying drawings. In view of the problems mentioned in the above-mentioned background art, the present application provides a method for detecting the position and orientation accuracy of shaft hole assembly. The present application adopts the partial plane detection method. By fixing the assembled objects to each other and cutting them along a specific section, the assembly error is indirectly measured. Specifically, the spatial three-dimensional shape of the hole and the shaft is constructed by using the surface shape point cloud data of the inner side wall of the hole and the surface shape point cloud data of the outer side wall of the shaft assembled in advance, and the axis fitting is performed on the spatial three-dimensional shape of the hole and the shaft to obtain the first Axis; according to the spatial three-dimensional shape of the hole and the shaft, take a section plane after the shaft hole is assembled to obtain the first shaft hole section, and determine the one with the highest similarity to the first shaft hole section in the spatial three-dimensional shape of the hole and the shaft through data alignment. The first hole section and the first shaft section; the coordinates of the second axis corresponding to the first hole section and the coordinates of the third axis corresponding to the first shaft section are obtained respectively through the coordinate relationship of the first axis, according to the coordinates of the second axis and The coordinates of the third axis calculate the inclination and coaxiality between the second axis and the third axis, so as to determine the accuracy of the shaft hole assembly position and orientation of the shaft hole assembly. So as to accurately detect the closely matched mating surface data. As a result, problems such as detection of the assembly accuracy of the shaft hole are solved.

Specifically, FIG. 1 is a flowchart of a method for detecting the accuracy of an assembly position and orientation of a shaft hole provided by an embodiment of the present application.

As shown in Figure 1, the method for detecting the position and orientation accuracy of the shaft hole assembly includes the following steps:

In step S101, using the pre-collected surface point cloud data of the hole inner side wall and the surface point cloud data of the outer side wall of the shaft, the spatial three-dimensional shape of the hole and the shaft is constructed, and the spatial three-dimensional shape of the hole and the shaft is obtained by axis fitting. first axis.

It will be appreciated that the definition of assembly accuracy depends on the axis of the hole and the shaft. For inspection tasks, it is necessary to accurately find the axis of the hole and the shaft. In the production process, the actual axis of the hole and the shaft cannot be directly measured, so it is necessary to estimate the axis of the object according to the shape of the object. Due to the existence of manufacturing errors, there is a certain difference between the actual shape of the hole and the shaft and the theoretical shape of the corresponding digital model. And this manufacturing error is often random. Relying on the shape of a single cross-section of the bore and shaft, the estimated axis is not accurate.

Therefore, in the embodiments of the present application, the contact three-dimensional measuring machine is used to detect the complete spatial three-dimensional shape of the hole and the shaft, and the axis of the object is fitted by relying on the complete spatial three-dimensional shape of the hole and the shaft, so as to estimate the axis of the hole and the shaft more efficiently. precise.

It should be noted that the embodiments of the present application take the assembly of a hole and a single shaft in a group of shafts as an example to describe in detail the above-mentioned method for detecting the assembly position and orientation accuracy of the shaft hole.

Optionally, in an embodiment of the present application, the first axis is obtained by performing axis fitting on the spatial three-dimensional shape of the hole and the shaft, including: when the hole in which the shaft hole is assembled or the side wall of the shaft is a cylindrical surface, according to the hole The surface point cloud data of the inner side wall and the surface point cloud data of the outer side wall of the shaft construct a cylindrical three-dimensional shape in space, and the cylindrical axis is used as the first axis; when the hole of the shaft hole assembly or part of the side wall of the shaft is a cylindrical surface, From the point cloud data of the surface shape of the inner side wall of the hole and the surface shape point cloud data of the outer side wall of the shaft, the point cloud data whose side wall is a cylindrical surface are screened, and the cylindrical three-dimensional shape of the space is constructed according to the screened point cloud data, and the axis of the cylinder is used as the first axis.

Specifically, on the basis of detecting the point cloud of the outer surface, the measurement data is further fitted into a space cylinder, and the axis of the cylinder obtained is regarded as the axis of the hole or the shaft. As shown in Figure 2, first use the contact type three-coordinate measuring equipment to obtain the surface point cloud data of the inner side wall of the hole and the surface point cloud data of the outer side wall of the shaft. The surface point cloud data of the inner side wall of the hole is recorded as

C={c _i | _ci =(x _c,i ,y _c,i ,z _c,i ),i=1,2,K,m}

The surface point cloud data of the outer side wall 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, according to the measured results, referring to the theoretical digital model of the hole shaft, fit the actual axis of the hole and the shaft.

For holes or shafts whose side walls are cylindrical surfaces, there is no need to filter the point cloud data, and the cylindrical axis can be directly fitted by using the complete point cloud data; for holes whose main part is a cylindrical surface and a small area is a non-cylindrical surface Or axis, you need to filter out the point cloud data corresponding to the cylindrical surface area, and then use the point cloud data corresponding to the cylindrical surface area to fit the cylindrical axis.

Further, in the embodiment of the present application, the specific implementation of the above-mentioned screening of the cylindrical surface area from the overall point cloud is as follows:

Taking a hole as an example, as shown in Figure 3, several neighboring points are sequentially obtained for each point c _i in the point cloud data C, and these neighboring points are fitted into a plane and the plane normal n _c,i is obtained. The normals corresponding to each point in the point cloud data obtained by the above method are approximately coplanar with each other. The normal n _c,ax of the approximate plane in which all these normals lie is an approximation of the hole axis. Project all point clouds to the base along the normal n _c,ax . Inside the base, the projected point is denoted pc _i . Most of the projected point clouds are distributed in circles, and a few are distributed in straight lines. Fits all point clouds after projecting to the base as a circle. The area 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 recorded as pc _max . Taking pc _max as the center, find several nearby points on both sides to fit into a straight line, judge the distance d _i between all projected points pc _i and the straight line, set the threshold d _lim to judge the boundary of the straight line area, and filter out all the circles. point pc _i distributed in a shape, and then filter out all points c _i distributed in a cylindrical shape.

Optionally, in an embodiment of the present application, after the first axis is obtained by performing axis fitting on the spatial three-dimensional shape of the hole and the shaft, the method further includes: constructing an initial equation of the first axis in the shaft hole assembly coordinate system, according to The fitting process determines the initial parameters of the initial equation; constructs the error equation of the initial equation, solves the error equation by the linearized least squares method, and obtains the linearized error equation; brings the surface point cloud data of the inner side wall of the hole into the linearized error equation, Obtain the parameter adjustment amount of the initial equation, adjust the initial parameter according to the parameter adjustment amount, and update the initial equation; iterate multiple times until the iteration end condition is satisfied, output the current initial equation, and obtain the coordinate relationship of the first axis.

Specifically, in the embodiment of the present application, the above method of fitting the axis from the cylindrical surface area is as follows: as shown in FIG. 4 ,

The space cylinder is characterized by an equation with x ₀ , y ₀ , z ₀ , r,l,m,n as parameters:

(xx ₀ ) ² +(yy ₀ ) ² +(zz ₀ ) ² -r ² =[l(xx ₀ )+m(yy ₀ )+n(zz ₀ )] ²

Among them, x ₀ , y ₀ , z ₀ are the intersection points on the axis of the cylinder and the bottom surface, r is the radius of the cylinder section, (l,m,n), ||(l,m,n)|| ₂ =1 is the Unit normal vector parallel to the cylinder axis.

选取点云筛选过程获得的底面与近似轴线n_c,ax的交点作为参数x₀,y₀,z₀的初值

选取点云筛选过程获得的所有投影至底面的点拟合圆的半径作为参数r的初值

A specific implementation method for obtaining the parameters x ₀ , y ₀ , z ₀ , r,l,m,n is the nonlinear least squares method. Taking the hole as an example, first, the approximate axis n _c,ax is obtained in combination with the point cloud screening process, and the initial values of the parameters l,m,n are determined

Select the intersection of the bottom surface obtained by the point cloud screening process and the approximate axis n _c,ax as the initial values of the parameters x ₀ , y ₀ , z ₀

Select the radius of the fitting circle of all points projected to the bottom obtained by the point cloud screening process as the initial value of the parameter r

The error equation is constructed as follows:

e(x,y,z)=(xx ₀ ) ² +(yy ₀ ) ² +(zz ₀ ) ² -r ² -[l(xx ₀ )+m(yy ₀ )+n(zz ₀ )] ²

For a least squares fit, all points ci = (x _{c,i ,} y _c,i ,z _c,i ) are expected to have the smallest fit residuals. Since the error equation has a nonlinear structure for the parameters x ₀ , y ₀ , z ₀ , r, l, m, n, an iterative linearized least squares method is used to solve the optimal parameters. As shown in Figure 5, note:

The error equation is linearized and written as:

获得更新后的参数。In the formula, the partial derivatives are expanded for the parameters x ₀ , y ₀ , z ₀ , r, l, m, and n respectively. At this point, the problem has been transformed into a linear least squares problem. All the filtered points in the point set C are brought into the linearized error equation at one time, and the parameter adjustment amounts Δx ₀ , Δy ₀ , Δz ₀ , Δr, Δl, Δm, Δn can be obtained. Add the parameter adjustment amounts Δx ₀ , Δy ₀ , Δz ₀ , Δr, Δl, Δm, Δn to the initial value of the parameter

Get the updated parameters.

Continue to use the updated parameters as the initial values, and repeat the above-mentioned process of linearization and least squares until the parameter adjustment amounts Δx ₀ , Δy ₀ , Δz ₀ , Δr, Δl, Δm, Δn are less than a certain threshold, it is considered that the parameter x ₀ , y ₀ , z ₀ , r,l,m,n converge.

In step S102, according to the spatial three-dimensional shape of the hole and the shaft, a section plane after the shaft hole is assembled is taken to obtain the first shaft hole section, and the spatial three-dimensional shapes of the hole and the shaft are respectively determined by data alignment to be similar to the first shaft hole section. The highest degree of the first hole section and the first shaft section.

It can be understood that after detecting the outer surface type point cloud and fitting the measurement data to a space cylinder, the fitting axis of the hole or shaft is obtained. However, since the definition of the assembly error depends on the relative positional relationship between the hole and the axis of the shaft, it is also necessary to detect the outer shape of the hole and the shaft respectively.

Since the hole and the shaft are in the assembled state and are in contact with each other or a small gap (micron level), the general non-contact measurement methods (industrial CT, ultrasonic testing, etc.) cannot accurately obtain the required shape data of the hole and the shaft . Therefore, in the embodiments of the present application, a more accurate detection method is adopted, that is, the assembled shaft hole is filled with photosensitive resin and then cut open after curing. The shape is measured.

It should be noted that the holes and shaft surfaces are pre-coated with light-curing resin before assembly. After the assembly is performed, the resin is cured by irradiation with UV light and the holes are securely connected to the shaft. Referring to the three-dimensional shape detection results of the hole and shaft space, a specific section is selected as the cutting plane, and a section is milled from the assembled shaft hole along the selected cutting plane. Thus, the above-mentioned first shaft hole section and first shaft section are obtained.

Optionally, in an embodiment of the present application, the first hole section and the first shaft section with the highest similarity to the first shaft hole section in the spatial three-dimensional shapes of the hole and the shaft are respectively determined by data alignment, including: for For any section in the three-dimensional shape of space, the boundary distance between the curve of the hole and the shaft on the left and right sides of any section and the curve of the hole and the shaft in the first shaft hole section is determined based on the method of dynamic time normalization; The boundary distance and the smallest section are taken as the first hole section and the first axis section.

After the assembly is completed, under the microscope inspection screen, the boundary of the hole and the shaft can be detected at the same time. Due to the limited field of view of the microscope, it is often difficult to space the left and right borders within the field of view at the same time. Therefore, the boundaries of the hole and the shaft on the left and right sides of the section will be measured separately.

In the coordinate system of one side, define the boundary of the hole and the shaft. At this time, the boundary between the hole and the shaft is in the form of a two-dimensional point cloud. The surface point cloud data of the inner side wall of the hole on the left and right sides are recorded as:

The surface point cloud data of the left and right sides of the shaft outer wall are recorded as:

相对位置关系未知，上述的点云数据

相对位置关系同样未知。但

处于同一个坐标系内，具备已知的相互位置关系，

处于同一个坐标系内，具备已知的相互位置关系。It is worth noting that the point cloud data on the left and right sides are independent of each other. The above point cloud data

The relative position relationship is unknown, the above point cloud data

The relative positional relationship is also unknown. but

are in the same coordinate system and have a known mutual positional relationship,

They are in the same coordinate system and have a known mutual positional relationship.

Due to the deviation between the actual section plane and the theoretical section plane selected above, it is inaccurate to estimate the hole and shaft axis in the actual section plane by directly using the theoretical section plane and the actual section plane for data alignment. Therefore, a certain search algorithm is required to search for the section with the most similar plane two-dimensional shape corresponding to the actual section in the three-dimensional shape of the space.

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

Taking the hole as an example, in the 3D point cloud data C, with the initial theoretical section as the center, within a certain angle range and displacement range, search for the section that is most similar to the actual section.

Further, a specific implementation method of similarity judgment is based on a dynamic time warping (Dynamic Time Warping, DTW) method. In the section cf in the three-dimensional shape of a certain space, the surface point cloud data of the inner and side walls of the hole on the left and right sides are recorded as:

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 ^rc _,i ,z ^rc _,i ),i=1,2,K,q}

In the same section, the surface point cloud data of the left and right sides of the shaft outer wall are recorded as:

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 worth noting that the point cloud data of holes and shafts are independent of each other. The relative positional relationship between the above-mentioned point cloud data C ^l , G ^l is unknown, and the relative positional relationship between the above-mentioned point cloud data C ^r , G ^r is also unknown. However, C ^l and C ^r are in the same coordinate system and have a known mutual positional relationship ^, while Gl and ^Gr are in the same coordinate system and have a known mutual positional relationship.

It should be noted that the detected quantity includes the spatial three-dimensional shape of the hole and shaft before assembly, and the plane two-dimensional shape of the hole and shaft after assembly. By manually controlling the cut section, the corresponding relationship between the plane two-dimensional shape in the section and the spatial three-dimensional shape of the hole and the shaft can be roughly determined, but it is not accurate. Therefore, a more accurate data alignment method is to take the artificial control section as the search center, and within a certain angle and displacement variation range, search for the section that is most similar to the plane two-dimensional shape corresponding to the actual section in the three-dimensional shape of the space.

The data alignment process for holes and shafts is performed separately. Select a section in the search range for the spatial 3D profile of a hole or shaft. Calculate the similarity between the left and right holes or shaft boundaries of the section and the left and right holes or shaft boundaries corresponding to the actual section respectively. The section with the highest total similarity on the left and right sides is taken as the section with the most similar plane two-dimensional shape corresponding to the actual section.

最为相似。使用DTW方式判断两条曲线的距离，左右两侧的边界的距离分别记作：Specifically, taking the data alignment of holes as an example, it is necessary to find a most suitable section cf* in the three-dimensional shape C of the hole space, so that the point cloud data C ^l and C ^r on the left and right sides are respectively the same as the measured data on the left and right sides.

most similar. Use the DTW method to judge the distance of the two curves, and the distance between the left and right sides of the boundary is recorded as:

One of the most suitable cross-sections cf* in the three-dimensional shape C of the hole space satisfies:

此平面内，孔轴线(l,m,n)投影为

孔上点(x₀,y₀,z₀)投影为

Correspondingly, the surface point cloud data of the inner side wall of the hole on the left and right sides of the section cf* is recorded as

In this plane, the projection of the hole axis (l,m,n) is

The point on the hole (x ₀ , y ₀ , z ₀ ) is projected as

此平面内，轴轴线(l,m,n)投影为

轴上点(x₀,y₀,z₀)投影为

Likewise, using a similar method, a most suitable section gf* can be found in the spatial three-dimensional shape G of the shaft. Correspondingly, the surface point cloud data of the left and right sides of the axis outside the section gf* are recorded as

In this plane, the shaft axis (l,m,n) is projected as

The point on the axis (x ₀ , y ₀ , z ₀ ) is projected as

In step S103, the coordinates of the second axis corresponding to the cross section of the first hole and the coordinates of the third axis corresponding to the cross section of the first axis are obtained through the coordinate relationship of the first axis, respectively. According to the coordinates of the second axis and the coordinates of the third axis Calculate the inclination and coaxiality between the second axis and the third axis to determine the accuracy of the shaft hole assembly pose of the shaft hole assembly.

After obtaining the above-mentioned first hole section and first shaft section, due to the limited field of view under the high magnification state, the data of the inner hole in the section and the left and right sides of the shaft were measured respectively, and the measurement results were located in two independent coordinate systems. Data interrelationships are unknown. However, the definition of assembly accuracy depends on the axis of the hole and the shaft. In a plane section, it is reflected as the inclination and coaxiality between the axis of the hole and the shaft. Therefore, it is necessary to convert the above two independent coordinate systems to detect with the accuracy of the assembly pose.

It can be understood that, for the hole and the shaft, respectively, the two-dimensional plane shape obtained by the above search is optimally matched to the plane two-dimensional shape of the measured section. At this time, the axis of the plane two-dimensional shape obtained by searching the three-dimensional shape of the respective space for the hole and the shaft is the axis of the assembled hole and the shaft. Then, the tilt error and coaxial error of the two axes are calculated.

Optionally, in an embodiment of the present application, the coordinates of the second axis corresponding to the cross section of the first hole and the coordinates of the third axis corresponding to the cross section of the first axis are obtained respectively through the coordinate relationship of the first axis. Calculate the inclination and coaxiality between the second axis and the third axis, including: obtaining the hole axis projection and the point projection on the hole of the second axis according to the coordinate relationship of the first axis; The coordinate relationship of the axes obtains the axis projection of the third axis and the projection of the point on the axis; according to the projection of the point on the hole and the projection of the point on the axis, the angle between the second axis and the third axis is calculated by the angle calculation formula, and the angle is obtained according to the angle. The inclination between the second axis and the third axis; according to the projection of the hole axis, the projection of the axis of the shaft, the projection of the point on the hole and the projection of the point on the shaft, the axis distance between the second axis and the third axis of the shaft thickness center is calculated using the axis distance calculation formula , the coaxiality between the second axis and the third axis is obtained according to the axis spacing of the center of the thickness of the shaft.

Specifically, in the embodiments of this application, the mutual positions of the coordinate systems where the two plane point cloud data are located are defined as:

In the formula, P and Q are two plane point cloud data, d _x , d _z , θ _y are the translation and rotation relationship of the two coordinate systems.

是已知的，为恢复轴线，因此需要确定

或

二者是一样的，即

从而确定孔与轴拟合圆柱面在同一个坐标系下的相对关系，进而确定孔与轴轴线的相对关系。In the above steps,

is known, in order to restore the axis, it is necessary to determine

or

Both are the same, namely

Thereby, the relative relationship between the hole and the shaft fitting cylindrical surface in the same coordinate system is determined, and then the relative relationship between the hole and the shaft axis is determined.

Assume

where 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 are the relative positional relationships between the point clouds to be determined.

通过已知的各点云间的相对位置关系

以及待确定的各点云间的相对位置关系

转化至

所在的坐标系。具体转换方法为：point cloud

Through the known relative positional relationship between each point cloud

and the relative positional relationship between the point clouds to be determined

convert to

the coordinate system in which it is located. The specific conversion method is:

In the formula, the function P is the translation and rotation function of the point cloud, the first parameter is the original data, and the second parameter is the relative positional relationship between the used point clouds.

所在的坐标系后，构建优化问题，求解待确定的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。优化目标为：Convert all point clouds to

After the coordinate system is located, the optimization problem is constructed to solve the 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 to be determined. The optimization objective is:

是显微镜的测量结果，

是坐标机检测结果，

的点数小于

的点数。因此式中使用最近点搜索函数c，用于依次搜索

中与

各点的欧氏距离最近点。because

is the measurement result of the microscope,

is the coordinate machine detection result,

points less than

of points. Therefore, the nearest point search function c is used in the formula to search sequentially

neutral

The Euclidean distance of each point is the closest point.

可以认为是装配后孔与轴左右两侧边界。上述平面sf*中孔轴线投影

与孔上点投影

平面gf*中轴轴线投影

与轴上点投影

一同转换至

所在的坐标系。转换后的孔的轴线记为

孔点投影记为

转换后的轴的轴线记为

轴点投影记为

After nonlinear optimization, 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. Correspondingly, after assembly, the plane two-dimensional numbers on the left and right sides of the hole and the shaft have been registered with the spatial three-dimensional data. at this time,

It can be considered as the boundary between the hole and the left and right sides of the shaft after assembly. Projection of the hole axis in the above plane sf*

Point projection with hole

Plane gf* central axis projection

Projected with on-axis point

convert to

the coordinate system in which it is located. The axis of the converted hole is recorded as

The hole point projection is recorded as

The axis of the transformed shaft is denoted as

The axis point projection is recorded as

进行定义，具体地实施方法如下：Assembly errors in this application can be based on

The definition is carried out, and the specific implementation method is as follows:

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

Axis tilt on-axis error is defined as the axis spacing from the center of the shaft thickness:

where l is the thickness of the shaft.

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

S1: Hole and shaft space 3D shape detection and shaft center fitting:

The complete space three-dimensional shape of the hole and the shaft is detected by the contact three-dimensional measuring machine, and the axis of the object is fitted depending on the complete space three-dimensional shape of the hole and the shaft. On the basis of detecting the point cloud of the outer surface, the measured data is further fitted to a space cylinder, and the axis of the cylinder obtained is regarded as the axis of the hole or shaft.

S2: Hole and shaft assembly, curing, sectioning:

Before assembly, the holes and shaft surfaces are pre-coated with light-curing resin. After the assembly is performed, the resin is cured by irradiation with UV light and the holes are securely connected to the shaft. Referring to the three-dimensional shape detection results of the hole and shaft space, a specific section is selected as the cutting plane, and a section is milled from the assembled shaft hole along the selected cutting plane.

S3: Two-dimensional shape detection of holes and shaft planes in the section:

The assembled shaft hole was filled with photosensitive resin, cured and cut open, and the plane two-dimensional shape of the cross-section inner hole and the shaft was measured by a high magnification microscope (1000 times). Due to the limited field of view under the high magnification state, the data on the left and right sides of the hole in the section and the shaft were measured separately. The measurement results were located in two independent coordinate systems, and the relationship between the data on the left and right sides was unknown.

S4: Alignment of the plane 2D shape and the space 3D shape data in the section:

Taking the artificial control section as the search center, within a certain angle and displacement variation range, the section in the three-dimensional shape of the space that is most similar to the plane two-dimensional shape corresponding to the actual section is searched. The data alignment process for holes and shafts is performed separately. Taking a hole as an example, select a section in the search range of the three-dimensional shape of the hole. Calculate the similarity between the hole boundaries on the left and right sides of the section and the corresponding hole boundaries on the left and right sides of the actual section respectively. The section with the highest total similarity on the left and right sides is taken as the section with the most similar plane two-dimensional shape corresponding to the actual section.

S5: Section inner hole and shaft axis recovery and assembly accuracy detection:

At this time, the axis of the plane two-dimensional shape obtained by searching the three-dimensional shape of the respective space for the hole and the shaft is the axis of the assembled hole and the shaft. Then, the tilt error and coaxial error of the two axes are calculated.

According to the method for detecting the position and orientation accuracy of the shaft hole assembly proposed by the embodiment of the present application, the spatial three-dimensional shape of the hole and the shaft is constructed by using the surface shape point cloud data of the inner side wall of the shaft hole assembly and the surface shape point cloud data of the outer side wall of the shaft, which are collected in advance. The first axis is obtained by the axis fitting of the spatial three-dimensional shape of the hole and the shaft; according to the spatial three-dimensional shape of the hole and the shaft, a section plane after the assembly of the shaft hole is cut to obtain the first shaft hole section, and the hole and the shaft are respectively determined by data alignment. The first hole section and the first shaft section with the highest similarity to the first shaft hole section in the spatial three-dimensional shape of the Corresponding to the coordinates of the third axis, the inclination and coaxiality between the second axis and the third axis are calculated according to the coordinates of the second axis and the third axis, so as to determine the position and orientation accuracy of the shaft hole assembly. Thereby, the closely fitting mating surface profile data can be accurately detected.

Next, with reference to the accompanying drawings, the device for detecting the accuracy of the assembly position and orientation of the shaft hole according to the embodiment of the present application will be described.

FIG. 7 is a schematic block diagram of an apparatus for detecting the position and orientation accuracy of a shaft hole assembly according to an embodiment of the present application.

As shown in FIG. 7 , the apparatus 10 for detecting the position and orientation accuracy of the shaft-hole assembly includes: a fitting module 100 , an intercepting module 200 and an accuracy detection module 300 .

Among them, the fitting module 100 is used to construct the spatial three-dimensional shape of the hole and the shaft by using the surface shape point cloud data of the inner side wall of the hole and the surface shape point cloud data of the outer side wall of the shaft assembled in advance. The first axis is obtained by fitting the axis; the interception module is used to intercept a section plane after the assembly of the shaft hole according to the spatial three-dimensional shape of the hole and the shaft to obtain the first shaft hole section, and determine the spatial three-dimensional shape of the hole and the shaft respectively through data alignment. The first hole section and the first shaft section with the highest similarity with the first shaft hole section; the precision detection module 300 is used to obtain the coordinates of the second axis corresponding to the first hole section and the first axis through the coordinate relationship of the first axis, respectively. The coordinates of the third axis corresponding to the cross section of a shaft, calculate the inclination and coaxiality between the second axis and the third axis according to the coordinates of the second axis and the third axis, so as to determine the shaft hole assembly posture of the shaft hole assembly precision.

Optionally, in an embodiment of the present application, the fitting module 100 includes: a construction unit for, when the hole in which the shaft hole is assembled or the side wall of the shaft is a cylindrical surface, according to the point cloud data of the surface shape of the inner side wall of the hole and the The surface point cloud data of the outer side wall of the shaft constructs a cylindrical three-dimensional shape in space, and the axis of the cylinder is used as the first axis; From the surface point cloud data of the inner side wall and the surface point cloud data of the outer side wall of the shaft, screen the point cloud data whose side wall is a cylindrical surface, and construct a cylindrical three-dimensional shape according to the screened point cloud data, with the axis of the cylinder as the first axis.

Optionally, in an embodiment of the present application, after the first axis is obtained by performing axis fitting on the spatial three-dimensional contours of the hole and the shaft, the method further includes: a parameter determination module, configured to perform an axis on the spatial three-dimensional contours of the hole and the shaft. After the first axis is obtained by fitting, the initial equation of the first axis is constructed in the shaft hole assembly coordinate system, and the initial parameters of the initial equation are determined according to the fitting process; the solving module is used to construct the error equation of the initial equation, using the linearization minimum The square method solves the error equation and obtains the linearized error equation; the adjustment module is used to bring the point cloud data of the inner side wall of the hole into the linearized error equation to obtain the parameter adjustment amount of the initial equation, and adjust the initial parameters according to the parameter adjustment amount, And update the initial equation; the iterative module is used to iterate multiple times until the iteration end condition is satisfied, output the current initial equation, and obtain the coordinate relationship of the first axis.

Optionally, in an embodiment of the present application, the interception module 200 includes: a distance determination unit, configured to determine the left and right sides of any cross section based on the method of dynamic time normalization for any section in the three-dimensional shape of the space, respectively. The boundary distance between the curve of the hole and the shaft and the curve of the hole and the shaft in the first shaft hole section; the selection unit is used to select the left and right boundary distance and the smallest section as the first hole section and the first shaft section respectively.

Optionally, in an embodiment of the present application, the accuracy detection module 300 includes: a first projection unit, configured to obtain the hole axis projection and the point projection on the hole of the second axis according to the coordinate relationship of the first axis; The projection unit is used to obtain the shaft axis projection and the on-axis point projection of the third axis according to the coordinate relationship of the first axis; the first calculation unit is used to calculate the third axis according to the point projection on the hole and the on-axis point projection using the included angle calculation formula. The angle between the second axis and the third axis is used to obtain the inclination between the second axis and the third axis according to the angle; the second calculation unit is used for the projection of the hole axis, the projection of the axis of the axis, the projection of the point on the hole and the point on the axis The projection calculates the axis distance of the shaft thickness center between the second axis and the third axis by using the axis distance calculation formula, and obtains the coaxiality between the second axis and the third axis according to the axis distance of the shaft thickness center.

It should be noted that, the foregoing explanations of the embodiment of the method for detecting the position and orientation accuracy of the shaft hole assembly are also applicable to the detection device for the position and posture accuracy of the shaft hole assembly in this embodiment, which will not be repeated here.

According to the detection device for the assembly position and orientation accuracy of the shaft hole proposed in the embodiment of the present application, firstly, the three-dimensional shape detection and shaft center fitting are performed on the hole and the shaft; then, before the assembly, the surface of the hole and the shaft is pre-coated with light curing resin. After the assembly is performed, the resin is cured by irradiation with UV light and the holes are securely connected to the shaft. And referring to the three-dimensional shape detection results of the hole and shaft space, a specific section is selected as the section plane, and the assembled shaft hole is milled out a section along the selected section plane; The two-dimensional shape of the plane is aligned with the three-dimensional shape data of the space. Finally, the inner hole of the section and the axis of the shaft are restored, and the assembly accuracy is detected. Thereby, the closely fitting mating surface profile data is accurately detected.

FIG. 8 is a schematic structural diagram of an electronic device provided by an embodiment of the present application. The electronic device may include:

Memory 801 , processor 802 , and computer programs stored on memory 801 and executable on processor 802 .

When the processor 802 executes the program, the method for detecting the position and orientation accuracy of the assembly of the shaft hole provided in the above embodiment is implemented.

Further, the electronic device also includes:

The communication interface 803 is used for communication between the memory 801 and the processor 802 .

The memory 801 is used to store computer programs that can be executed on the processor 802 .

The memory 801 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk memory.

If the memory 801, the processor 802 and the communication interface 803 are independently implemented, the communication interface 803, the memory 801 and the processor 802 can be connected to each other through a bus and complete communication with each other. The bus may be an Industry Standard Architecture (referred to as ISA) bus, a Peripheral Component (referred to as PCI) bus, or an Extended Industry Standard Architecture (referred to as EISA) bus or the like. The bus can be divided into address bus, data bus, control bus and so on. For convenience of representation, only one thick line is used in FIG. 8, but it does not mean that there is only one bus or one type of bus.

Optionally, in terms of specific implementation, if the memory 801, the processor 802 and the communication interface 803 are integrated on one chip, the memory 801, the processor 802 and the communication interface 803 can communicate with each other through an internal interface.

The processor 802 may be a central processing unit (Central Processing Unit, CPU for short), or a specific integrated circuit (Application Specific Integrated Circuit, ASIC for short), or is configured to implement one or more of the embodiments of the present application integrated circuit.

This embodiment also provides a computer-readable storage medium on which a computer program is stored, characterized in that, when the program is executed by a processor, the above method for detecting the position and orientation accuracy of an assembly of a shaft hole is implemented.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature 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 of the embodiments or examples. Furthermore, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other.

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

Any process or method description in the flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or N more executable instructions for implementing custom logical functions or steps of the process , and the scope of the preferred embodiments of the present application includes alternative implementations in which the functions may be performed out of the order shown or discussed, including performing the functions substantially concurrently or in the reverse order depending upon the functions involved, which should It is understood by those skilled in the art to which the embodiments of the present application belong.

It should be understood that various parts of this 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 memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented by any one of the following techniques known in the art, or a combination thereof: discrete with logic gates for implementing logic functions on data signals Logic circuits, application specific integrated circuits with suitable combinational logic gates, Programmable Gate Arrays (PGA), Field Programmable Gate Arrays (FPGA), etc.

Those of ordinary skill in the art can understand that all or part of the steps carried by the methods of the above embodiments can be completed by instructing the relevant hardware through a program, and the program can be stored in a computer-readable storage medium, and the program is stored in a computer-readable storage medium. When executed, one or a combination of the steps of the method embodiment is included.

Claims (12)

1. a detection method of shaft hole assembly pose accuracy, is characterized in that, comprises the following steps: Using the pre-collected surface point cloud data of the inner side wall of the hole and the surface point cloud data of the outer side wall of the shaft, the spatial three-dimensional shape of the hole and the shaft is constructed, and the first axis is obtained by the axis fitting of the spatial three-dimensional shape of the hole and the shaft. ; According to the spatial three-dimensional shape of the hole and the shaft, a section plane after assembly of the shaft hole is cut to obtain the first shaft hole section, and the spatial three-dimensional shape of the hole and the shaft is determined by data alignment to the first shaft. The first hole section and the first axis section with the highest hole section similarity; 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 are obtained through the coordinate relationship of the first axis, respectively. According to the coordinates of the second axis and the third axis The coordinates of the axis are used to calculate the inclination and coaxiality between the second axis and the third axis, so as to determine the accuracy of the shaft hole assembly position and orientation of the shaft hole assembly. 2 . The method according to claim 1 , wherein the first axis is obtained by performing axis fitting on the spatial three-dimensional shape of the hole and the shaft, comprising: 2 . When the side wall of the hole or shaft assembled by the shaft hole is a cylindrical surface, a cylindrical space three-dimensional shape is constructed according to the surface point cloud data of the inner side wall of the hole and the surface point cloud data of the outer side wall of the shaft. the axis of the cylinder as the first axis; When part of the side wall of the hole or shaft assembled by the shaft hole is a cylindrical surface, filter the points where the side wall is a cylindrical surface from the surface point cloud data of the inner side wall of the hole and the surface point cloud data of the outer side wall of the shaft From the cloud data, a cylindrical spatial three-dimensional shape is constructed according to the filtered point cloud data, and the axis of the cylindrical shape is used as the first axis. 3. The method according to claim 1, characterized in that, after the first axis is obtained by performing axis fitting on the spatial three-dimensional shape of the hole and the shaft, the method further comprises: constructing the initial equation of the first axis in the shaft hole assembly coordinate system, and determining the initial parameters of the initial equation according to the fitting process; constructing an error equation of the initial equation, and solving the error equation by using the linearized least squares method to obtain a linearized error equation; Bringing the surface point cloud data of the inner side wall of the hole into the linearized error equation to obtain the parameter adjustment amount of the initial equation, adjusting the initial parameter according to the parameter adjustment amount, and updating the initial equation; Iterates multiple times until the end condition of the iteration is satisfied, outputs the current initial equation, and obtains the coordinate relationship of the first axis. 4 . The method according to claim 1 , wherein the first hole section and the first hole section with the highest similarity to the first shaft hole section in the spatial three-dimensional shapes of the hole and the shaft are respectively determined through data alignment. 5 . The first axis section, including: For any section in the three-dimensional shape of the space, a method based on dynamic time normalization is used to determine the difference between the curve of the hole and the shaft on the left and right sides of the any section and the curve of the hole and the shaft in the first shaft hole section, respectively. border distance; The left and right boundary distances and the smallest section are respectively selected as the first hole section and the first shaft section. 5 . The method according to claim 1 , wherein the coordinates of the second axis corresponding to the cross section of the first hole and the coordinates corresponding to the cross section of the first shaft are obtained respectively through the coordinate relationship of the first axis. 6 . Coordinates of the third axis, calculating the inclination and coaxiality between the second axis and the third axis according to the coordinates of the second axis and the third axis, including: Obtain the hole axis projection and the point projection on the hole of the second axis according to the coordinate relationship of the first axis; According to the coordinate relationship of the first axis, the axis axis projection and the on-axis point projection of the third axis are obtained; Calculate the angle between the second axis and the third axis according to the projection of the point on the hole and the point on the shaft using the angle calculation formula, and obtain the second axis and the third axis according to the angle. The inclination between the third axes; Calculate the axis of the center of the shaft thickness between the second axis and the third axis according to the hole axis projection, the shaft axis projection, the point projection on the hole and the point projection on the shaft using the axis distance calculation formula The coaxiality between the second axis and the third axis is obtained according to the axis distance of the center of the thickness of the shaft. 6. A detection device for shaft hole assembly pose accuracy, characterized in that it comprises: The fitting module is used to construct the spatial three-dimensional shape of the hole and the shaft by using the pre-collected surface point cloud data of the inner side wall of the hole and the surface point cloud data of the outer side wall of the shaft, and the three-dimensional shape of the hole and the shaft. Fitting to get the first axis; The intercepting module is used for intercepting a section plane after the assembly of the shaft hole according to the three-dimensional spatial shape of the hole and the shaft to obtain the first shaft hole section, and determining the spatial three-dimensional shape of the hole and the shaft through data alignment. the first hole section and the first shaft section with the highest similarity of the first shaft hole section; An accuracy detection module, configured to obtain 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 relationship of the first axis, respectively, according to the second axis The coordinates of the axis and the coordinates of the third axis are used to calculate the inclination and coaxiality between the second axis and the third axis, so as to determine the position and orientation accuracy of the shaft hole assembly of the shaft hole assembly. 7. The device according to claim 6, wherein the fitting module comprises: The construction unit is used for constructing a cylindrical three-dimensional space according to the surface point cloud data of the inner side wall of the hole and the surface point cloud data of the outer side wall of the shaft when the side wall of the hole or the shaft of the shaft hole assembly is a cylindrical surface Outline, taking the axis of the cylinder as the first axis; The screening unit is used for screening the side wall in the surface point cloud data of the inner side wall of the hole and the surface point cloud data of the outer side wall of the shaft when the side wall of the hole or the shaft assembled by the shaft hole is a cylindrical surface is the point cloud data of the cylindrical surface, and a cylindrical three-dimensional shape in space is constructed according to the filtered point cloud data, and the axis of the cylinder is used as the first axis. 8. The apparatus of claim 6, further comprising: The parameter determination module is used to perform axis fitting on the spatial three-dimensional shape of the hole and the shaft to obtain the first axis, construct the initial equation of the first axis in the shaft hole assembly coordinate system, and determine the first axis according to the fitting process. the initial parameters of the initial equation; a solving module for constructing the error equation of the initial equation, and solving the error equation by using the linearized least squares method to obtain the linearized error equation; The adjustment module is used to bring the surface point cloud data of the inner side wall of the hole into the linearized error equation, obtain the parameter adjustment amount of the initial equation, adjust the initial parameter according to the parameter adjustment amount, and update all the parameters. Describe the initial equation; The iterative module is used to iterate multiple times until the end condition of the iteration is satisfied, output the current initial equation, and obtain the coordinate relationship of the first axis. 9. The apparatus according to claim 6, wherein the intercepting module comprises: The distance determination unit is used to determine, for any section in the three-dimensional shape of the space, the curve of the hole and the axis on the left and right sides of the any section and the hole section of the first axis based on the method of dynamic time adjustment respectively. The boundary distance of the hole and the axis curve; A selection unit is used to respectively select the left and right boundary distances and the smallest section as the first hole section and the first shaft section. 10. The device according to claim 6, wherein the precision detection module comprises: a first projection unit, configured to obtain the hole axis projection and the point projection on the hole of the second axis according to the coordinate relationship of the first axis; a second projection unit, configured to obtain the shaft axis projection and the on-axis point projection of the third axis according to the coordinate relationship of the first axis; The first calculation unit is configured to calculate the angle between the second axis and the third axis according to the projection of the point on the hole and the projection of the point on the shaft by using the angle calculation formula, and obtain the obtained value according to the angle. an inclination between the second axis and the third axis; A second calculation unit, configured to calculate the second axis and the third axis according to the projection of the hole axis, the projection of the axis of the shaft, the projection of the point on the hole and the projection of the point on the axis by using the calculation formula of the distance between the axes The axial spacing between the shaft thickness centers, and the coaxiality between the second axis and the third axis is obtained according to the axial spacing between the shaft thickness centers. 11. An electronic device, comprising: a memory, a processor, and a computer program stored on the memory and runnable on the processor, the processor executing the program to implement the program as claimed in the claim The method for detecting the position and orientation accuracy of the shaft hole assembly described in any one of the requirements 1-5. 12. A computer-readable storage medium on which a computer program is stored, characterized in that the program is executed by a processor for realizing the shaft hole assembly pose accuracy as claimed in any one of claims 1-5 detection method.

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