Assembly optimization method, device and equipment based on contact surface shape error

Abstract

The present application provides an assembly optimization method, device and equipment based on contact surface shape error, the method adjusts the first contact surface in the specified assembly according to the target adjustment angle to obtain the adjusted first contact surface; calculates the difference between the point cloud data corresponding to the adjusted first contact surface and the second contact surface under the specified coordinate axis to obtain the reconstructed first nominal vector; under the boundary conditions of the preload increment of the minimum detectable preload and the assembly process requirements, the second nominal vector is optimized according to the reconstructed first nominal vector to obtain the preload when the vector length of the second nominal vector is the smallest; according to the correlation between the second nominal vector and the coaxiality, the coaxiality of the first connector and the second connector is obtained; according to the target adjustment angle, preload and coaxiality, the first contact surface and the second contact surface are assembled. It can be seen that the technical solution provided in this embodiment can improve the coaxiality and assembly accuracy.

Description

Technical Field

[0001] This application relates to precision assembly technology, and particularly to an assembly optimization method, device, and equipment based on the shape error of the contact surface. Background Art

[0002] With the increasing requirements for the precision and stability of precision assembly in the fields of aviation, aerospace, military, and medical, higher and higher requirements are put forward for the assembly quality of mechanical products, especially the connection assembly precision of connectors. Based on this, improving the precision and stability of precision instruments is an important guarantee for supporting the development of the industry. Taking the threaded flange connection as an example, the threaded flange connection structure is a commonly used structure in precision assembly. However, due to the large number of threaded connectors, the change in the coaxiality of the connection structure after the application of the threaded pre-tightening force is very significant, resulting in extremely difficult installation and adjustment of this connection structure.

[0003] In current actual production, the design process parameters of the pre-tightening torque of the threaded connectors in more than 99% of the threaded flange connection structures are exactly the same. However, in precision assembly, due to the shape error of the assembly surface of the connection structure, the contact state of the contact surface is very uneven, and under the action of the same screw pre-tightening force, the axis directions of the two connectors will deviate, resulting in a decrease in coaxiality and ultimately low assembly precision. Summary of the Invention

[0004] This application provides an assembly optimization method, device, and equipment based on the shape error of the contact surface to improve the assembly precision on the basis of improving the coaxiality.

[0005] In a first aspect, an embodiment of this application provides an assembly optimization method based on the shape error of the contact surface. The method includes:

[0006] Adjusting the first contact surface in a specified assembly body according to a target adjustment angle to obtain an adjusted first contact surface; wherein, the target adjustment angle is the adjustment angle corresponding to the uniform contact state obtained after the angle adjustment of the first nominal vector, and the first nominal vector is obtained by calculating the difference between the respective point cloud data of a pair of contact surfaces in a specified assembly body under a specified coordinate axis and then fitting the difference into a vector.

[0007] Calculating the difference between the respective point cloud data of the adjusted first contact surface and the second contact surface under a specified coordinate axis to obtain a reconstructed first nominal vector; wherein, the first contact surface and the second contact surface are a pair of contact surfaces; the point cloud data is the data containing shape error obtained through actual measurement.

[0008] Under the boundary conditions of the preload increment that meets the minimum detectable preload and the assembly process requirements, according to the reconstructed first nominal vector, optimize the second nominal vector representing the excellent degree of coaxiality between the first connector and the second connector to obtain the preload when the vector length of the second nominal vector is minimized; wherein, the first connector is the connector to which the first contact surface belongs, and the second connector is the connector to which the second contact surface belongs;

[0009] According to the second nominal vector and the correlation between the second nominal vector and the coaxiality, obtain the coaxiality between the first connector and the second connector;

[0010] According to the target adjustment angle, the preload and the coaxiality, assemble the first contact surface and the second contact surface.

[0011] In a second aspect, an assembly optimization device based on the shape error of the contact surface provided by an embodiment of the present application includes:

[0012] A first contact surface adjustment unit for adjusting the first contact surface in a specified assembly according to a target adjustment angle to obtain an adjusted first contact surface; wherein, the target adjustment angle is the adjustment angle corresponding to the uniform contact state obtained after the angle adjustment of the first nominal vector, and the first nominal vector is obtained by calculating the difference between the respective point cloud data of a pair of contact surfaces in the specified assembly under the specified coordinate axis and then fitting the difference into a vector;

[0013] A first nominal vector reconstruction unit for calculating the difference between the respective point cloud data of the adjusted first contact surface and the second contact surface under the specified coordinate axis to obtain a reconstructed first nominal vector; wherein, the first contact surface and the second contact surface are a pair of contact surfaces; the point cloud data is the data containing shape errors obtained through actual measurement;

[0014] A preload obtaining unit for optimizing the second nominal vector representing the excellent degree of coaxiality between the first connector and the second connector according to the reconstructed first nominal vector under the boundary conditions of the preload increment that meets the minimum detectable preload and the assembly process requirements, to obtain the preload when the vector length of the second nominal vector is minimized; wherein, the first connector is the connector to which the first contact surface belongs, and the second connector is the connector to which the second contact surface belongs;

[0015] A coaxiality obtaining unit for obtaining the coaxiality between the first connector and the second connector according to the second nominal vector and the correlation between the second nominal vector and the coaxiality;

[0016] An assembly unit for assembling the first contact surface and the second contact surface according to a target to adjust the angle, the pre-tightening force, and the coaxiality.

[0017] As can be seen from the above technical solutions, in this application, the angle of the first contact surface in the specified assembly is adjusted according to the target to obtain the adjusted first contact surface; the difference between the respective point cloud data of the adjusted first contact surface and the second contact surface under the specified coordinate axis is calculated to obtain the reconstructed first nominal vector; under the boundary conditions of the pre-tightening force increment that meets the minimum detectable pre-tightening force and the assembly process requirements, the second nominal vector is optimized according to the reconstructed first nominal vector to obtain the pre-tightening force when the vector length of the second nominal vector is minimized; according to the correlation between the second nominal vector and the coaxiality, the coaxiality of the first connector and the second connector is obtained; the first contact surface and the second contact surface are assembled according to the target adjusted angle, the pre-tightening force, and the coaxiality. It can be seen that the technical solution provided in this embodiment performs angle adjustment processing based on the point cloud data of the contact surface containing shape errors. The contact surface after angle adjustment processing can uniformly improve the contact state between the first connector and the second connector, thereby improving the connection attitude accuracy of the first connector and the second connector after assembly. On the premise of meeting the process requirements and the pre-tightening force increment, the second nominal vector is optimized to obtain the second nominal vector with the minimum vector length, and the improvement of the coaxiality is determined based on the correlation between the second nominal vector and the coaxiality, so as to improve the connection attitude accuracy of the first connector and the second connector after assembly, thereby improving the coaxiality and the assembly accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure.

[0019] Figure 1 It is a schematic flowchart of an assembly optimization method based on the shape error of the contact surface provided by this application;

[0020] Figure 2 It is a schematic diagram of a threaded flange connection structure provided by this application;

[0021] Figure 3 It is a schematic flowchart of determining the first nominal vector provided by this application;

[0022] Figure 4 It is a schematic diagram of the first nominal contact surface and the first nominal vector provided by this application;

[0023] FIG. 5(a) is a schematic diagram of coordinate system establishment and assembly angle adjustment of a threaded flange connection structure provided by this application;

[0024] Figure 5(b) is an equivalent contact model of a control area of a threaded connection member provided by the present application;

[0025] Figure 6 is a schematic structural diagram of an assembly optimization device based on a contact surface shape error provided by the present application;

[0026] Figure 7 is a schematic structural diagram of an electronic device provided by the present application. Specific embodiments

[0027] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] See Figure 1 , Figure 1 is a flowchart of an assembly optimization method based on a contact surface shape error provided by an embodiment of the present application. This method is applied to an electronic device, and the method includes the following steps:

[0029] Step 101: Adjust the first contact surface in a specified assembly according to a target adjustment angle to obtain an adjusted first contact surface.

[0030] Wherein, the target adjustment angle is the adjustment angle corresponding to a uniform contact state obtained after the first nominal vector is adjusted by an angle. The first nominal vector is obtained by calculating the difference between the respective point cloud data of a pair of contact surfaces in a specified assembly under a specified coordinate axis and then performing vector fitting on the difference.

[0031] The first nominal vector is only named for the convenience of distinguishing from the nominal vector in the following text, and is not used to limit a certain nominal vector.

[0032] The first contact surface is only named for the convenience of distinguishing from the contact surfaces in the following text, and is not used to limit a certain contact surface.

[0033] The target adjustment angle can be an adjustment angle input by a user, or obtained from other electronic devices, or an adjustment angle stored locally. The present embodiment does not limit this.

[0034] It should be noted that research shows that improving the surface contact uniformity of the contact surface and the accuracy of regional stress control of the pre-tightening force of the threaded connection member are important guarantees for improving the threaded flange connection structure.

[0035] Step 102: Calculate the difference between the respective point cloud data of the adjusted first contact surface and the second contact surface under a specified coordinate axis to obtain a reconstructed first nominal vector.

[0036] Among them, the first contact surface and the second contact surface are a pair of contact surfaces. The first contact surface and the second contact surface are a pair of assembly surfaces for assembly in the specified assembly. The point cloud data is the data containing shape errors obtained through actual measurement;

[0037] Here, the second contact surface is only named for convenience of description and is not used to define a certain contact surface.

[0038] The specified coordinate axis can be the X-axis, the Y-axis, or the Z-axis. Specifically, which axis it is can be selected according to the actual assembly. In this embodiment, the rotatable Z-axis is used as the specified axis.

[0039] In this embodiment, the coordinate values corresponding to the X-axis and Y-axis of the point cloud data of the first contact surface and the point cloud data of the second contact surface remain unchanged, and the difference processing is performed on the coordinate values corresponding to the Z-axis of the point cloud data of the first contact surface and the point cloud data of the second contact surface to obtain a difference value. The coordinate values of the X-axis and Y-axis of the first nominal vector remain unchanged, and the coordinate value of the Z-axis is the difference value.

[0040] Step 103, under the boundary conditions of the preload increment that satisfies the minimum detectable preload and the assembly process requirements, according to the reconstructed first nominal vector, optimize the second nominal vector representing the coaxiality excellence degree between the first connecting piece and the second connecting piece to obtain the preload when the vector length of the second nominal vector is minimized.

[0041] Among them, the first connecting piece is the connecting piece to which the first contact surface belongs, and the second connecting piece is the connecting piece to which the second contact surface belongs.

[0042] The first connecting piece is only named for convenience of distinguishing from the connecting pieces in the following text and is not used to define a certain connecting piece.

[0043] Here, the second connecting piece is only named for convenience of description and is not used to define a certain connecting piece. The second nominal vector is only named for convenience of description and is not used to define a certain nominal vector.

[0044] In this embodiment, the second nominal vector is an optimization model related to the first nominal vector and the preload. The boundary conditions are the preload increment that satisfies the minimum detectable preload and the assembly process requirements. The optimization objective is to minimize the vector length of the second nominal vector. Based on this, the objective optimization model is optimized to obtain the preload when the vector length of the second nominal vector is minimized.

[0045] Step 104, according to the second nominal vector and the correlation between the second nominal vector and the coaxiality, obtain the coaxiality between the first connecting piece and the second connecting piece.

[0046] There is a correlation between the second nominal vector and the coaxiality. After determining the second nominal vector, the coaxiality is determined according to this correlation.

[0047] Taking the threaded connection structure as an example, as Figure 2 shown, the first connecting member 1 and the second connecting member 2 are connected by i threaded connecting members 3. The coaxiality δ of the first connecting member 1 and the second connecting member 2 can be determined according to the expression δ = tanα·(D1 + D2), where the vector is the state of the first connecting member 1 and the second connecting member 2 in the ideal assembly state (i.e., the coaxiality is 0), and the vector is the state after actual assembly. D1 is the length of the first connecting member in the axial direction, and D2 is the length of the second connecting member in the axial direction. If the offsets of the first connecting member 1 and the second connecting member 2 perpendicular to the axial direction are not considered, α is the included angle between the vector and the vector .

[0048] Step 105, assemble the first contact surface and the second contact surface according to the target adjustment angle, pre-tightening force and coaxiality.

[0049] During actual assembly, the first contact surface and the second contact surface can be assembled according to the target adjustment angle, the pre-tightening force determined in step 103, and the coaxiality determined in step 104, so that the contact state between the assembled first contact surface and the second contact surface can be uniform, thereby improving the assembly accuracy.

[0050] Complete Figure 1 the step flow chart shown.

[0051] It can be seen that in the technical solution provided in this application, the angle adjustment is processed based on the point cloud data of the contact surface including shape errors. The contact surface after angle adjustment can improve the uniformity of the contact state between the first connecting member and the second connecting member, so that the connection attitude accuracy of the first connecting member and the second connecting member after assembly is improved. On the premise of meeting the process requirements and the pre-tightening force increment, the second nominal vector is optimized to obtain the second nominal vector with the minimum vector length, and the improvement of the coaxiality is determined according to the correlation between the second nominal vector and the coaxiality, so that the connection attitude accuracy of the first connecting member and the second connecting member after assembly is improved, thereby improving the coaxiality and the assembly accuracy.

[0052] In some embodiments, as Figure 3 shown, before completing step 101, the method further includes the following steps:

[0053] Step 106: Obtain the point cloud data of any pair of contact surfaces in the specified assembly, and calculate the difference between the point cloud data corresponding to each of the pair of contact surfaces under the specified coordinate axes to obtain the target point cloud data serving as the first nominal contact surface.

[0054] In this step, the point cloud data can be obtained by measuring the first contact surface of the actual assembly part, i.e., the first connecting part, and the second contact surface of the second connecting part using a scanner or a coordinate measuring instrument.

[0055] The first nominal contact surface is named only for the convenience of distinguishing from the nominal contact surface in the following text, and is not used to define a certain nominal contact surface.

[0056] Exemplarily, as Figure 4 shown, subtract the Z-axis data of the point cloud data (X m , Y m , Z m ) of the first contact surface 11 with shape error from the point cloud data (X n , Y n , Z n ) of the second contact surface 21 with shape error to obtain the target point cloud data (X m , Y m , Z m - Z n ) of the first nominal contact surface 4. In this embodiment, X m , Y m , Z m respectively represent the coordinate values corresponding to the point cloud data of the first contact surface 11 on the X-axis, Y-axis, and Z-axis; X n , Y n , Z n respectively represent the coordinate values corresponding to the point cloud data of the second contact surface 11 on the X-axis, Y-axis, and Z-axis.

[0057] Step 107: For each target point cloud data, perform vector fitting on the target point cloud data to obtain the first nominal vector after fitting.

[0058] As an embodiment, the implementation method of step 107 can be: for each target point cloud data, perform vector fitting on the target point cloud data in polar coordinate form to obtain the first nominal vector after fitting.

[0059] Exemplarily, perform vector fitting on the first nominal contact surface 4 with respect to the ideal plane 5 in polar coordinate form. For details, refer to Figure 4 . The ideal plane is a plane with a completely flat surface and no any shape error.

[0060] Step 108: Adjust each first nominal vector according to its corresponding set angle, and obtain the target adjustment angle corresponding to the first nominal vector used to represent a uniform contact state from the first nominal vectors after the adjustment angle.

[0061] Based on the above example, the vector is the vector at the first threaded connector in the coordinate system as shown in Figure 4 (the positive x-axis direction in Figure 4 ), and is encoded and sorted according to the positive rotation direction of the coordinate system angle (such as the arrow direction in Figure 4 ), and the assembly at this time is defined as the initial assembly state of the first connector and the second connector. The vector is the vector at the second threaded connector in the specified coordinate system, is the first nominal vector, is the vector at the i-th threaded connector, θ i is the angle of the i-th threaded connector in the coordinate system, θ i-1 is the angle of the (i - 1)-th threaded connector in the coordinate system, L(θ) is the vector length on the first nominal contact surface in the coordinate system, and n is the number of threaded connectors.

[0062] On the basis of the initial assembly state, in the direction of the arrow shown in Fig. 5(a), the first connector rotates around the Z axis with O as the center on the second connector. The rotation angle for each adjustment is β = 2π / i, that is, the incremental angle is β = 2π / i. The first connector is adjusted i - 1 times in angle, and the first nominal vector is solved for the assembly state after each adjustment. Adding the initial state, there are i assembly states and i first nominal vectors in total. Calculate Take the smallest The corresponding assembly angle, that is, the target adjustment angle, is the final assembly state after the installation angle adjustment. The adjustment angle at this time, that is, the target adjustment angle, is denoted as θ, thus completing the optimization of the assembly angle.

[0063] It can be seen that by applying the technical solution provided in this embodiment, a first nominal vector representing a uniform contact state can be obtained, so as to improve the assembly accuracy of the pair of contact surfaces.

[0064] As an embodiment, the implementation method of implementing step 108 may include the following steps:

[0065] Step A1: For each first nominal vector, adjust the first nominal vector according to its corresponding set angle.

[0066] In this step, each first nominal vector corresponds to a set angle. In other words, each first nominal vector is adjusted according to its corresponding set angle.

[0067] Step A2: Calculate the vector lengths of the first nominal vectors after each adjustment angle, and obtain the target first nominal vector with the minimum vector length from the first nominal vectors after each adjustment angle.

[0068] Calculate the vector lengths of each first nominal vector, obtain the minimum vector length from the calculated vector lengths, and then determine the adjustment angle corresponding to the minimum vector length as the target adjustment angle and the first nominal vector.

[0069] As another embodiment, the implementation method of step 108 may include the following steps:

[0070] Step B1: Obtain a first nominal vector from the first nominal vectors in a set order, adjust the first nominal vector at the initial position according to the corresponding set angle, calculate the vector length of the first nominal vector at the initial position after the angle adjustment, and determine it as the minimum vector length.

[0071] In this step, the first nominal vectors are sorted in advance. According to the sorting order of the first nominal vectors, the first nominal vector at the initial position is adjusted according to the corresponding set angle.

[0072] In this step, the minimum vector length is the vector length of the first nominal vector at the initial position.

[0073] It should be noted that there is a one-to-one correspondence between the first nominal vectors and the set angles.

[0074] Step B2: Take the next first nominal vector obtained in the set order as the current first nominal vector, adjust the current first nominal vector according to the corresponding set angle, calculate the vector length of the current first nominal vector, and compare it with the minimum vector length. If the vector length of the current first nominal vector is greater than the minimum vector length and the current first nominal vector is not the last first nominal vector, then return to execute step B2; if the vector length of the current first nominal vector is less than or equal to the minimum vector length and the current first nominal vector is not the last first nominal vector, then execute step B3. If the vector length of the current first nominal vector is less than or equal to the minimum vector length and the current first nominal vector is the last first nominal vector, then execute step B4.

[0075] In this step, adjusting the current first nominal vector according to the corresponding set angle can be understood as adjusting the current first nominal vector according to the set angle corresponding to this current first nominal vector.

[0076] Step B3: Determine the vector length of the current first nominal vector as the minimum vector length, and return to execute step B2;

[0077] Step B4: Determine the current first nominal vector as the first nominal vector representing a uniform contact state and the target adjustment angle corresponding to the current first nominal vector.

[0078] It can be seen that in this embodiment, the first nominal vector representing a uniform contact state and the target adjustment angle are determined one by one according to the sorting order of the first nominal vectors.

[0079] As an embodiment, an implementation manner of implementing step 103 may include the following steps:

[0080] Step C: Optimize the following expression to obtain the pre-tightening force when the vector length of the second nominal vector is minimized;

[0081] Optimize the following expression to obtain the pre-tightening force when the vector length of the second nominal vector is minimized;

[0082] The expression is:

[0083] Wherein, is the second nominal vector, represents the unit vector at the i-th threaded fastener on the contact surface, represents the length of the control area where the i-th threaded fastener is located in the specified coordinate axis direction after deformation under the applied pre-tightening force. i is the serial number of the i-th threaded fastener, n is the number of threaded fasteners, and ΔL i is the deformation of the i-th thread control area, is the displacement generated by the control area where the k-th threaded fastener is located on the control area where the i-th threaded fastener is located. k is the serial number of the k-th threaded fastener, λ: Specified constant, is the subsidence angle, and L i is the length of the control area where the i-th threaded fastener is located in the specified coordinate axis direction, and p i is the pressure generated by the pre-tightening force of the i-th threaded fastener in the control area where the i-th threaded fastener is located. a is the radius of the control area where the threaded fastener is located, and r i k is the distance between the center of the k-th threaded fastener and the center of the i-th threaded fastener. G represents the shear modulus of the material, and ΔH i is the elastic subsidence displacement generated by the uniformly distributed circular load in the control area, and ΔH i = F i b L i / EA i , E is the elastic modulus of the material, and F i bis the pre-tightening force of the i-th threaded fastener after the adjusted angle, A i is the area of the control region to which the i-th threaded fastener belongs, L i is the length of the control region to which the i-th threaded fastener belongs in the specified coordinate axis direction.

[0084] In this embodiment, as shown in FIG. 5(b), the control region is the region determined according to the first connection line and the second connection line. First, the reference line is determined. The reference line is formed by connecting the origin O in the coordinate system to which the first contact surface or the second contact surface belongs and the center of the i-th threaded part; the first connection line is a line starting from the reference line and rotating π / n angles in the positive direction of the polar coordinate axis with O as the center; the second connection line is a line starting from the reference line and rotating π / n angles in the negative direction of the polar coordinate axis with O as the center.

[0085] The pre-tightening force increment is the variable value of the pre-tightening force of the threaded fastener at each step in the optimization process, and the minimum detectable pre-tightening force value of the threaded fastener is used as the increment condition.

[0086] The process requirement is the change range of the pre-tightening force of the threaded fastener in the optimization process, and this change range can also be called the process range value.

[0087] The second nominal vector is the normal vector of the second nominal contact surface, and the second nominal contact surface is the contact surface after the first nominal contact surface is deformed by applying the pre-tightening force.

[0088] See Figure 6 , Figure 6 is the device structure diagram of an assembly optimization device 600 based on the contact surface shape error provided in this embodiment. The device includes:

[0089] The first contact surface adjustment unit 601 is used to adjust the first contact surface in the specified assembly according to the target adjustment angle to obtain the adjusted first contact surface; wherein, the target adjustment angle is the adjustment angle corresponding to the uniform contact state obtained after the first nominal vector is adjusted by the angle, and the first nominal vector is obtained by calculating the difference between the respective point cloud data of a pair of contact surfaces in the specified assembly in the specified coordinate axis and then fitting the difference into a vector;

[0090] The first nominal vector reconstruction unit 602 is configured to calculate the difference between the point cloud data corresponding to the adjusted first contact surface and the second contact surface under a specified coordinate axis, so as to obtain the reconstructed first nominal vector; wherein, the first contact surface and the second contact surface are a pair of contact surfaces; the point cloud data is the data containing shape errors obtained through actual measurement; the pre-tightening force acquisition unit 603 is configured to optimize the second nominal vector representing the excellent degree of coaxiality between the first connecting member and the second connecting member according to the reconstructed first nominal vector under the boundary conditions of the pre-tightening force increment that meets the detectable minimum pre-tightening force and the assembly process requirements, so as to obtain the pre-tightening force when the vector length of the second nominal vector is minimized; wherein, the first connecting member is the connecting member to which the first contact surface belongs, and the second connecting member is the connecting member to which the second contact surface belongs;

[0091] The coaxiality acquisition unit 604 is configured to obtain the coaxiality between the first connecting member and the second connecting member according to the second nominal vector and the correlation between the second nominal vector and the coaxiality;

[0092] The assembly unit 605 is configured to assemble the first contact surface and the second contact surface according to the target adjustment angle, the pre-tightening force and the coaxiality.

[0093] As an embodiment, the assembly device further includes:

[0094] The target point cloud data acquisition unit is configured to acquire the point cloud data of any pair of contact surfaces in a specified assembly, and calculate the difference between the point cloud data corresponding to each of the pair of contact surfaces under a specified coordinate axis, so as to obtain the target point cloud data as the first nominal contact surface;

[0095] The vector fitting unit is configured to perform vector fitting on each target point cloud data to obtain the fitted first nominal vector;

[0096] The target adjustment angle acquisition unit is configured to adjust each first nominal vector according to the corresponding set angle, and obtain the target adjustment angle corresponding to the first nominal vector representing uniform contact state from the first nominal vectors after the adjustment angle.

[0097] As an embodiment, the target adjustment angle acquisition unit is specifically configured to:

[0098] For each first nominal vector, adjust the first nominal vector according to the corresponding set angle;

[0099] Calculate the vector length of each first nominal vector after the adjustment angle, and obtain the target first nominal vector with the minimum vector length from the first nominal vectors after the adjustment angle.

[0100] As an embodiment, the target adjustment angle obtaining unit is specifically configured to:

[0101] Obtain a first nominal vector from the first nominal vectors in a set order, adjust the first nominal vector at the initial position by a corresponding set angle, calculate the vector length of the first nominal vector at the initial position after the angle adjustment, and determine it as the minimum vector length;

[0102] Take the next first nominal vector obtained in the set order as the current first nominal vector, adjust the current first nominal vector by a corresponding set angle, calculate the vector length of the current first nominal vector, and compare it with the minimum vector length;

[0103] If the vector length of the current first nominal vector is greater than the minimum vector length and the current first nominal vector is not the last first nominal vector, then return to execute the step of taking the next first nominal vector obtained in the set order as the current first nominal vector;

[0104] If the vector length of the current first nominal vector is less than or equal to the minimum vector length and the current first nominal vector is not the last first nominal vector, then determine the vector length of the current first nominal vector as the minimum vector length, and return to execute the step of taking the next first nominal vector obtained in the set order as the current first nominal vector; if the vector length of the current first nominal vector is less than or equal to the minimum vector length and the current first nominal vector is the last first nominal vector, then determine the current first nominal vector as the first nominal vector representing a uniform contact state and the target adjustment angle corresponding to the current first nominal vector.

[0105] As an embodiment, when a pair of contact surfaces are contact surfaces assembled by a plurality of threaded connectors, the pre-tightening force obtaining unit 603 includes a pre-tightening force determining subunit for optimizing a second nominal vector representing the excellent degree of coaxiality between the first connector and the second connector according to the reconstructed first nominal vector, to obtain the pre-tightening force when the vector length of the second nominal vector is minimized, and is configured to:

[0106] Optimize the following expression to obtain the pre-tightening force when the vector length of the second nominal vector is minimized;

[0107] Optimize the following expression to obtain the pre-tightening force when the vector length of the second nominal vector is minimized;

[0108] The expression is:

[0109] Wherein, is the second nominal vector, represents the unit vector at the \(i\)-th threaded connector on the contact surface, represents the length of the control area to which the \(i\)-th threaded connector belongs in the specified coordinate axis direction after deformation under the applied pre-tightening force. \(i\) is the serial number of the \(i\)-th threaded connector, \(n\) is the number of threaded connectors, and \(\Delta L\) i is the deformation of the \(i\)-th thread control area, is the displacement generated by the control area to which the \(k\)-th threaded connector belongs on the control area to which the \(i\)-th threaded connector belongs. \(k\) is the serial number of the \(k\)-th threaded connector, \(\lambda\): specified constant, is the subsidence angle, \(L\) i is the length of the control area to which the \(i\)-th threaded connector belongs in the specified coordinate axis direction, \(p\) i is the pressure generated by the pre-tightening force of the \(i\)-th threaded connector in the control area to which the \(i\)-th threaded connector belongs. \(a\) is the radius of the control area to which the threaded connector belongs, \(r\) i k is the distance between the center of the \(k\)-th threaded connector and the center of the \(i\)-th threaded connector. \(G\) represents the material shear modulus, \(\Delta H\) i is the elastic subsidence displacement generated by the uniformly distributed circular load in the control area, \(\Delta H\) i \( = F\) i b \(L\) i / EA i , \(E\) is the material elastic modulus, \(F\) i b is the pre-tightening force of the \(i\)-th threaded connector after the adjusted angle, \(A\) i is the area of the control area to which the \(i\)-th threaded connector belongs, \(L\) i is the length of the control area to which the \(i\)-th threaded connector belongs in the specified coordinate axis direction.

[0110] It can be seen that the technical solution provided by the embodiment of the present application performs angle adjustment processing based on the point cloud data of the contact surface including shape errors. The contact surface after angle adjustment processing uniformly improves the contact state between the first connector and the second connector. On the premise of meeting the process requirements and the pre-tightening force increment, the pre-tightening force and the second nominal vector with the minimum vector length are obtained when the vector length of the second nominal vector reaches the minimum. According to the correlation relationship between the second nominal vector and the coaxiality, the coaxiality is determined, and the assembly is carried out based on the coaxiality, the target adjustment angle and the pre-tightening force to improve the coaxiality, and further improve the assembly accuracy of the first connector and the second connector.

[0111] The implementation processes of the functions and roles of each unit in the above device are specifically described in detail in the implementation processes of the corresponding steps in the above method, and will not be repeated here.

[0112] For the electronic device provided by the embodiment of the present application, from the hardware level, the schematic diagram of the hardware architecture can be referred to Figure 7 as shown. It includes: a machine-readable storage medium and a processor, where: the machine-readable storage medium stores machine-executable instructions that can be executed by the processor; the processor is used to execute the machine-executable instructions to implement the assembly operation disclosed in the above example.

[0113] The machine-readable storage medium provided by the embodiment of the present application stores machine-executable instructions. When the machine-executable instructions are called and executed by the processor, the machine-executable instructions cause the processor to implement the assembly operation disclosed in the above example.

[0114] Here, the machine-readable storage medium can be any electronic, magnetic, optical or other physical storage device that can contain or store information, such as executable instructions, data, etc. For example, the machine-readable storage medium can be: RAM (Random Access Memory), volatile memory, non-volatile memory, flash memory, storage drives (such as hard disk drives), solid-state drives, any type of storage disk (such as optical discs, DVDs, etc.), or similar storage media, or a combination thereof.

[0115] The systems, devices, modules or units illustrated in the above embodiments can be specifically implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer, and the specific form of the computer can be a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email transceiver device, a game console, a tablet computer, a wearable device, or a combination of any several of these devices.

[0116] For the convenience of description, the above devices are described by dividing them into various units according to functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0117] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the embodiments of the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0118] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, as well as the combination of flows and / or blocks in the flowchart and / or block diagram. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a means for implementing the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 means for implementing the functions specified in one or more blocks.

[0119] Moreover, these computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0120] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0121] For the apparatus embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to the partial descriptions of the method embodiments. The apparatus embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of the present application. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0122] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. An assembly optimization method based on contact surface shape error, characterized in that: The method comprises: The first contact surface in the specified assembly is adjusted according to the target adjustment angle to obtain the adjusted first contact surface; wherein the target adjustment angle is the adjustment angle corresponding to the uniform contact state obtained after the first nominal vector is adjusted, and the first nominal vector is obtained by calculating the difference between the corresponding point cloud data of a pair of contact surfaces in the specified assembly under the specified coordinate axis and then performing vector fitting on the difference; Calculate the difference between the point cloud data corresponding to the adjusted first contact surface and the second contact surface under the specified coordinate axis to obtain a reconstructed first nominal vector; wherein the first contact surface and the second contact surface are a pair of contact surfaces; and the point cloud data are data obtained through actual measurement and contain shape errors; Under the boundary conditions of satisfying the preload increment of the minimum detectable preload and the assembly process requirements, according to the reconstructed first nominal vector, the second nominal vector representing the degree of excellence of the coaxiality of the first connector and the second connector is optimized to obtain the preload that minimizes the vector length of the second nominal vector; wherein the first connector is the connector to which the first contact surface belongs, and the second connector is the connector to which the second contact surface belongs; Obtaining the coaxiality of the first connecting member and the second connecting member according to the second nominal vector and the association relationship between the second nominal vector and the coaxiality; The first contact surface and the second contact surface are assembled according to the target adjustment angle, the preload force and the coaxiality.

2. The assembly optimization method according to claim 1, characterized in that: Before adjusting the first contact surface in the specified assembly according to the target adjustment angle, the method further includes: Obtaining point cloud data of any pair of contact surfaces in a specified assembly, and calculating the difference between the point cloud data corresponding to the pair of contact surfaces under the specified coordinate axis, to obtain target point cloud data as the first nominal contact surface; For each target point cloud data, vector fitting is performed on the target point cloud data to obtain a first nominal vector after fitting; Each first nominal vector is adjusted according to its corresponding set angle, and a target adjustment angle corresponding to the first nominal vector indicating a uniform contact state is obtained from the first nominal vector after the angle adjustment.

3. The assembly optimization method according to claim 2, characterized in that: The first nominal vectors are adjusted according to their corresponding set angles, and a target adjustment angle corresponding to the first nominal vector indicating a uniform contact state is obtained from the first nominal vectors after the angle adjustment, including: For each first nominal vector, adjusting the first nominal vector according to the corresponding set angle; The vector lengths of the first nominal vectors after each adjustment angle are calculated, and a target first nominal vector with the smallest vector length is obtained from the first nominal vectors after each adjustment angle.

4. The assembly optimization method according to claim 2, characterized in that: The first nominal vectors are adjusted according to their corresponding set angles, and a target adjustment angle corresponding to the first nominal vector indicating a uniform contact state is obtained from the first nominal vectors after the angle adjustment, including: Obtaining a first nominal vector from the first nominal vector according to a set order, adjusting the first nominal vector at the initial position according to a corresponding set angle, and calculating a vector length of the first nominal vector at the initial position after the angle adjustment, and determining it as a minimum vector length; Taking the next first nominal vector obtained in the set order as the current first nominal vector, adjusting the current first nominal vector according to the corresponding set angle, calculating the vector length of the current first nominal vector, and comparing it with the minimum vector length; If the vector length of the current first nominal vector is greater than the minimum vector length, and the current first nominal vector is not the last first nominal vector, returning to execute the step of taking the next first nominal vector obtained in the set order as the current first nominal vector; If the vector length of the current first nominal vector is less than or equal to the minimum vector length, and the current first nominal vector is not the last first nominal vector, the vector length of the current first nominal vector is determined as the minimum vector length, and the step of returning to execute the next first nominal vector obtained in the set order as the current first nominal vector; if the vector length of the current first nominal vector is less than or equal to the minimum vector length, and the current first nominal vector is the last first nominal vector, the current first nominal vector is determined as the first nominal vector indicating that the contact state is uniform and the target adjustment angle corresponding to the current first nominal vector.

5. The assembly optimization method according to claim 1, characterized in that: When a pair of contact surfaces are contact surfaces assembled by a plurality of threaded connectors, the second nominal vector representing the degree of excellence of the coaxiality between the first connector and the second connector is optimized according to the reconstructed first nominal vector to obtain the preload force when the vector length of the second nominal vector is minimized, including: The following expression is optimized to obtain the preload force that minimizes the vector length of the second nominal vector; The expression is: in, is the second nominal vector, represents the unit vector at the i-th threaded connection on the contact surface, It represents the length of the control area of ​​the i-th threaded connection after the preload is applied and deformed in the specified coordinate axis direction. i is the serial number of the i-th threaded connection, n is the number of threaded connections, and ΔL i is the deformation variable of the i-th thread control area, is the displacement of the control area of ​​the k-th threaded connection to the control area of ​​the ith threaded connection, k is the serial number of the k-th threaded connection, λ: specifies a constant, is the sinking angle, L i is the length of the control area of ​​the i-th threaded connection in the direction of the specified coordinate axis, p i is the pressure generated by the preload of the ith threaded connection in the control area of ​​the ith threaded connection, a is the radius of the control area of ​​the threaded connection, r i k is the distance between the center of the kth threaded connection and the center of the ith threaded connection, G represents the shear modulus of the material, ΔH i is the elastic settlement displacement caused by the uniformly distributed circular load in the control area, ΔH i =F i b L i / EA i , E is the elastic modulus of the material, F i b is the preload force of the ith threaded connection after adjusting the angle, A i is the area of ​​the control region to which the i-th threaded connection belongs, L i It is the length of the control area of ​​the i-th threaded connection in the direction of the specified coordinate axis.

6. An assembly optimization device based on contact surface shape error, characterized in that: The device comprises: A first contact surface adjustment unit is used to adjust the first contact surface in the specified assembly according to a target adjustment angle to obtain an adjusted first contact surface; wherein the target adjustment angle is an adjustment angle corresponding to a uniform contact state obtained after the first nominal vector is adjusted, and the first nominal vector is obtained by calculating the difference between the corresponding point cloud data of a pair of contact surfaces in the specified assembly under a specified coordinate axis and then performing vector fitting on the difference; A first nominal vector reconstruction unit is used to calculate the difference between the point cloud data corresponding to the adjusted first contact surface and the second contact surface under the specified coordinate axis to obtain a reconstructed first nominal vector; wherein the first contact surface and the second contact surface are a pair of contact surfaces; and the point cloud data are data obtained through actual measurement and contain shape errors; A preload obtaining unit is used to optimize the second nominal vector representing the degree of excellence of the coaxiality between the first connector and the second connector according to the reconstructed first nominal vector under the boundary conditions of satisfying the preload increment of the minimum detectable preload and the assembly process requirements, so as to obtain the preload that minimizes the vector length of the second nominal vector; wherein the first connector is the connector to which the first contact surface belongs, and the second connector is the connector to which the second contact surface belongs; a coaxiality obtaining unit, configured to obtain the coaxiality of the first connecting member and the second connecting member according to the second nominal vector and the association relationship between the second nominal vector and the coaxiality; An assembly unit is used to assemble the first contact surface and the second contact surface according to a target adjustment angle, the preload force and the coaxiality.

7. The assembly optimization device according to claim 6, characterized in that: The assembly optimization device also includes: A target point cloud data acquisition unit is used to acquire point cloud data of any pair of contact surfaces in a specified assembly, and calculate the difference between the point cloud data corresponding to the pair of contact surfaces under a specified coordinate axis to obtain target point cloud data as a first nominal contact surface; A vector fitting unit is used to perform vector fitting on each target point cloud data to obtain a first nominal vector after fitting; The target adjustment angle obtaining unit is used to adjust each first nominal vector according to the corresponding set angle, and obtain the target adjustment angle corresponding to the first nominal vector indicating uniform contact state from the first nominal vector after the adjustment.

8. The assembly optimization device according to claim 7, characterized in that: The target adjustment angle obtaining unit is specifically used for: For each first nominal vector, adjusting the first nominal vector according to the corresponding set angle; The vector lengths of the first nominal vectors after each adjustment angle are calculated, and a target first nominal vector with the smallest vector length is obtained from the first nominal vectors after each adjustment angle.

9. The assembly optimization device according to claim 7, characterized in that: The target adjustment angle obtaining unit is specifically used for: Obtaining a first nominal vector from the first nominal vector according to a set order, adjusting the first nominal vector at the initial position according to a corresponding set angle, and calculating a vector length of the first nominal vector at the initial position after the angle adjustment, and determining it as a minimum vector length; Taking the next first nominal vector obtained in the set order as the current first nominal vector, adjusting the current first nominal vector according to the corresponding set angle, calculating the vector length of the current first nominal vector, and comparing it with the minimum vector length; If the vector length of the current first nominal vector is greater than the minimum vector length, and the current first nominal vector is not the last first nominal vector, returning to execute the step of taking the next first nominal vector obtained in the set order as the current first nominal vector; If the vector length of the current first nominal vector is less than or equal to the minimum vector length, and the current first nominal vector is not the last first nominal vector, the vector length of the current first nominal vector is determined as the minimum vector length, and the step of returning to execute the next first nominal vector obtained in the set order as the current first nominal vector; if the vector length of the current first nominal vector is less than or equal to the minimum vector length, and the current first nominal vector is the last first nominal vector, the current first nominal vector is determined as the first nominal vector indicating that the contact state is uniform and the target adjustment angle corresponding to the current first nominal vector.

10. An electronic device, characterized in that: The electronic device includes: a processor and a memory; The memory is used to store machine executable instructions; The processor is used to read and execute the machine executable instructions stored in the memory to implement the contact surface-based assembly operation as described in any one of the methods of claims 1 to 5.

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