Vision-guided method for determining a phase coupling of a measurement shaft system

Abstract

The application relates to the technical field of reducer visual assembly, and discloses a method for determining phase coupling of a measuring shaft system based on visual guidance. A coupling shaft is measured at an input end of a reducer, and a coupling shaft is measured at an output end of the reducer, T-shaped marks are engraved respectively, the length of the horizontal side of the T-shaped mark, the length of the vertical side of the T-shaped mark, the width of the T-shaped mark, the outer diameter of the spline and the pitch of the spline satisfy a required relationship, the accuracy during camera image recognition is improved, and therefore the assembly accuracy of the reducer is improved; in addition, the phase of a high-speed end measuring shaft system under standard state conditions and actual state conditions, the included angle between the horizontal side of the T-shaped mark of the input end measuring coupling shaft of the reducer and the positive direction of the X axis under the camera coordinate system are used to determine the rotation angle of the high-speed end measuring shaft system, the phase accurate coupling of the high-speed end and the input end measuring coupling shaft of the reducer is realized, and the phase accurate coupling of the low-speed end and the output end measuring coupling shaft of the reducer is realized. Therefore, the accurate automatic assembly of the reducer is realized.

Description

Technical Field

[0001] This application relates to the field of visual assembly technology for speed reducers, and in particular to a method for determining phase connection of a measurement shaft system based on visual guidance. Background Technology

[0002] Speed ​​reducers are critical components in manufacturing, and their accurate performance testing requires high-precision testing instruments. While manual assembly of speed reducers can handle some complex situations, the sheer number of speed reducers and the fatigue caused by manual operation significantly reduce efficiency and accuracy, making it difficult to meet the demands of large-scale industrial testing. Adopting an automated assembly system can avoid the inefficiency caused by manual assembly. It also improves safety during handling, effectively reducing the possibility of worker accidents during assembly.

[0003] To achieve automated assembly of the reducer, a spline is used as the connection method between the input and output ends of the reducer's transmission chain and the high- and low-speed measuring shafts, enabling quick-change connections between the high-speed and low-speed shafts.

[0004] However, how to achieve precise phase connection between the reducer and the high-speed and low-speed ends when using spline connections has become an urgent problem to be solved. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides a vision-guided method for determining phase connection of a measurement axis system, comprising the following steps:

[0006] S1: Measure the connecting shaft at the input end and the connecting shaft at the output end of the reducer, and etch T-shaped markings on each; the dimensions of the T-shaped markings satisfy the following relationship:

[0007] L h = k1×D;

[0008] L v = k2×D, and L v / L h = m;

[0009] W = k3×(D / P) n ×D;

[0010] |L v - L h |≤ΔL;

[0011] Among them, L h L represents the length of the horizontal side of the T-shaped sign. vThe vertical side length of the T-shaped mark is represented by D, the outer diameter of the spline is represented by P, the tooth pitch of the spline is represented by k1, k2, and k3, respectively, the proportional coefficients are represented by m, the proportional constant is represented by n, the exponential factor is represented by W, the horizontal side width of the T-shaped mark is represented by ΔL, and the preset length difference threshold is represented by ΔL.

[0012] S2: Under the standard connection phase state, measure the shaft phase φ1 at the high-speed end, and the angle α1 between the horizontal side of the T-shaped mark at the reducer input end and the positive X-axis direction in the camera coordinate system; measure the shaft phase φ2 at the low-speed end, and the angle α2 between the horizontal side of the T-shaped mark at the reducer output end and the positive X-axis direction in the camera coordinate system; the standard connection phase state is the state in which the high-speed end is connected to the reducer input end and the low-speed end is connected to the reducer output end at the test station;

[0013] S3: Move the high-speed end to the preparatory position and obtain the angle β1 between the phase γ1 of the high-speed end measurement axis and the horizontal side of the T-shaped mark at the input end of the reducer and the positive direction of the X-axis in the camera coordinate system.

[0014] S4: Calculate the rotation angle Δ1 of the high-speed end measuring shaft system based on γ1, β1, φ1, and α1;

[0015] S5: After rotating the high-speed end measuring shaft by Δ1 and connecting it to the input end of the reducer, move it to the test station;

[0016] S6: Obtain the phase γ2 of the low-speed end measurement axis in the camera coordinate system, and the angle β2 between the horizontal side of the T-shaped mark at the reducer output end and the positive X-axis in the camera coordinate system.

[0017] S7: Calculate the rotation angle Δ2 of the low-speed end measuring shaft system based on γ2, β2, φ2, and α2;

[0018] S8: Rotate the low-speed end measuring shaft by Δ2 and connect it to the output end of the reducer to complete the phase connection.

[0019] Furthermore, the formula for calculating the rotation angle Δ1 of the high-speed end measuring shaft system is as follows:

[0020] Δ1= ( γ 1-φ1) - ( β 1- α 1);

[0021] If Δ1 is negative, it indicates that the high-speed end measuring shaft system rotates counterclockwise by the angle |Δ1|.

[0022] If Δ1 is a non-negative value, it indicates that the high-speed end measuring shaft system rotates clockwise by the angle |Δ1|.

[0023] Furthermore, the formula for calculating the rotation angle Δ2 of the shaft system at the low-speed end is as follows:

[0024] Δ2= ( γ 2-φ2) - ( β 2- α 2).

[0025] If Δ2 is negative, it indicates that the high-speed end measuring shaft system rotates counterclockwise by the angle |Δ2|.

[0026] If Δ2 is a non-negative value, it represents the clockwise rotation angle |Δ2| of the high-speed end measuring shaft system.

[0027] Furthermore, under standard connection phase conditions, the method for obtaining the angle α1 between the horizontal side of the T-shaped mark at the input end of the reducer and the positive X-axis in the camera coordinate system is as follows:

[0028] The first image is obtained by taking a picture of the T-shaped mark at the input end of the reducer using a camera vision measurement system;

[0029] Identify the edges of the T-shaped marker in the first image, perform binarization processing, obtain the edges of the horizontal and vertical sides of the T-shaped marker, and fit the linear equations of the two sides in the camera coordinate system respectively;

[0030] Select two points A and B on the same side of the vertical edge of the T-shaped mark, and calculate the difference δ between the two points in the Y direction;

[0031] Based on the slope k and δ of the vertical straight line equation of the T-shaped mark and the acute angle θ between the horizontal side of the T-shaped mark and the positive X-axis direction (zero phase) in the camera coordinate system, determine the angle α1 between the horizontal side of the T-shaped mark at the input end of the reducer and the positive X-axis direction in the camera coordinate system.

[0032] Furthermore, based on the slope k and δ of the vertical straight line equation of the T-shaped marker and the acute angle θ between the horizontal side of the T-shaped marker and the positive X-axis direction (zero phase) in the camera coordinate system, the angle α1 between the horizontal side of the T-shaped marker at the input end of the reducer and the positive X-axis direction in the camera coordinate system is determined as follows:

[0033] If the slope k of the vertical line equation of the T-shaped marker is less than 0 and δ > 0, then α1 = θ;

[0034] If the slope k of the equation of the vertical line of the T-shaped marker is less than 0 and δ < 0, then α1 = 180º + θ;

[0035] If the slope k of the vertical line equation of the T-shaped marker is greater than 0 and δ > 0, then α1 = 360º - θ;

[0036] If the slope k of the vertical line equation of the T-shaped marker is greater than 0 and δ < 0, then α1 = 180º - θ.

[0037] Furthermore, obtaining the angle β1 between the horizontal side of the T-shaped mark at the input end of the reducer and the positive X-axis in the camera coordinate system includes:

[0038] A second image is obtained by taking a picture of the T-shaped mark at the input end of the reducer using a camera vision measurement system;

[0039] Identify the edges of the T-shaped marker in the second image, perform binarization processing, obtain the edges of the horizontal and vertical sides of the T-shaped marker, and fit the linear equations of the two sides in the camera coordinate system respectively;

[0040] Select two points A' and B' on the same side of the vertical edge of the T-shaped mark, and calculate the difference δ' between the two points in the Y direction;

[0041] Based on the slopes k` and δ` of the vertical straight line equation of the T-shaped marker and the acute angle θ` between the horizontal side of the T-shaped marker and the positive X-axis direction (zero phase) in the camera coordinate system, determine the angle β1 between the horizontal side of the T-shaped marker at the input end of the reducer and the positive X-axis direction in the camera coordinate system.

[0042] Furthermore, based on the slopes k` and δ` of the vertical straight line equation of the T-shaped marker and the acute angle θ` between the horizontal side of the T-shaped marker and the positive X-axis direction (zero phase) in the camera coordinate system, the angle β1 between the horizontal side of the T-shaped marker at the input end of the reducer and the positive X-axis direction in the camera coordinate system is determined as follows:

[0043] If the slope k` of the vertical line equation of the T-shaped marker is less than 0 and δ`>0, then β1=θ`;

[0044] If the slope k` of the vertical line equation of the T-shaped marker is less than 0 and δ` < 0, then β1 = 180º + θ`;

[0045] If the slope k` of the vertical line equation of the T-shaped marker is greater than 0 and δ`>0, then β1=360º-θ`;

[0046] If the slope k` of the vertical line equation of the T-shaped marker is greater than 0 and δ` < 0, then β1 = 180º - θ`.

[0047] Furthermore, the slots at the high-speed end, the splines at the input end of the reducer, the slots at the low-speed end, and the splines at the output end of the reducer are numbered respectively.

[0048] When the high-speed end is connected to the input end of the reducer in phase, the slot number of the high-speed end is consistent with the number of the spline teeth of the input end of the reducer.

[0049] When the low-speed end is connected to the output end of the reducer in phase, the slot number of the low-speed end is consistent with the number of the spline tooth of the output end of the reducer.

[0050] Furthermore, the width W of the horizontal side of the T-shaped sign is not less than a preset width threshold W. min .

[0051] The embodiments of this application have the following technical effects:

[0052] 1. The vision-guided measurement axis system phase connection determination method provided in this application etches T-shaped marks at the input and output ends of the reducer, respectively. The horizontal side length, vertical side length, and width of the T-shaped mark meet the required relationship with the outer diameter of the spline and the tooth pitch of the spline, thereby improving the accuracy of camera image recognition and thus improving the assembly accuracy of the reducer.

[0053] 2. Measure shaft phase at high speed under standard and actual conditions. 、 The angle between the horizontal side of the T-shaped mark at the input end of the reducer and the positive X-axis in the camera coordinate system determines the rotation angle of the measurement axis at the high-speed end, achieving precise phase connection between the high-speed end and the input end of the reducer; similarly, precise phase connection between the low-speed end and the output end of the reducer is achieved. This enables precise and automated assembly of the reducer. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0055] Figure 1 This is a flowchart of a vision-guided measurement axis system phase connection determination method provided in an embodiment of this application;

[0056] Figure 2 This is a schematic diagram showing the angle between the horizontal side of the T-shaped mark at the high-speed end measurement axis phase and the reducer input end in the camera coordinate system and the positive X-axis direction under the standard connection phase state provided in the embodiments of this application.

[0057] Figure 3 This is a schematic diagram showing the angle between the phase of the high-speed end measurement shaft system and the horizontal side of the T-shaped mark at the input end of the reducer in the camera coordinate system and the positive direction of the X-axis in the actual assembly state provided in the embodiments of this application.

[0058] Figure 4 This is a schematic diagram of the internal structure of the system and the position of the first camera vision measurement system at the high-speed end, as provided in the embodiments of this application.

[0059] Figure 5 This is a schematic diagram of the external structure of the detection system (excluding the camera vision measurement system) provided in the embodiments of this application;

[0060] Figure 6 This is a schematic diagram showing the position of the second camera vision measurement system and the worktable provided in the embodiments of this application;

[0061] Figure 7 This is a schematic diagram of the structure of the first camera vision measurement system connected to a high-speed terminal, as provided in an embodiment of this application.

[0062] Figure 8 This is a schematic diagram of the structure of the second camera vision measurement system installed on the workbench, as provided in an embodiment of this application.

[0063] 1. T-shaped marker; 2. Horizontal edge of the T-shaped marker; 3. Vertical edge of the T-shaped marker; 4. External spline end face; 5. High-speed end motor; 6. High-speed end barrel-shaped stand; 7. High-speed end measuring axis system; 8. Object being transported (tested reducer and adapter); 9. Low-speed end barrel-shaped stand; 10. Low-speed end measuring axis system; 11. Low-speed end motor; 12. First set of camera vision measurement system; 13. Workbench body; 14. Preparatory station; 15. Guide rail system; 16. Test station; 17. Second set of camera vision measurement system; 18. Extension plate; 19. Camera mounting bracket I; 20. Camera system I; 21. Camera system II; 22. Camera mounting bracket II. Detailed Implementation

[0064] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0065] As attached Figures 4 to 8 As shown, a vision-guided measurement axis system phase connection determination method is described. The detection instrument involved is existing technology and includes a worktable 13, a guide rail system 15, a high-speed end, a low-speed end, and a transported object (the measured reducer and adapter) 8. The high-speed end includes a high-speed end motor 5, a high-speed end barrel-shaped platform 6, a high-speed end measurement axis system 7 (including a high-speed end torque sensor and a high-speed end circular grating angle sensor), etc. The low-speed end includes a low-speed end barrel-shaped platform 9, a low-speed end measurement axis system 10 (including a low-speed end torque sensor and a low-speed end circular grating angle sensor), a low-speed end motor 11, etc. The guide rail system 15 includes a two-dimensional motion guide rail system and can move within its plane.

[0066] A system for determining phase connection of a measurement axis based on vision guidance includes a first camera vision measurement system 12 and a second camera vision measurement system 17. The first camera vision measurement system 12 includes an extension plate 18, a camera mounting bracket I19, and a camera system I20. The camera system I20 is fixed to the camera mounting bracket I19 and requires its own light source or an external light source to ensure the shooting quality of the T-shaped mark under the field of view. The camera mounting bracket I19 is fixed to the extension plate 18, which is fixed to the outside of the high-speed end barrel 6. The second camera vision measurement system 17 includes a camera mounting bracket II22 and a camera system II21. The camera mounting bracket II22 is fixed to the workbench and its structure is adapted according to the structural characteristics of the workbench and the test station. The camera system II21 is fixed to the camera mounting bracket II22, and its shooting field of view is directly facing the center of the preparatory station 14.

[0067] The application provides a vision-guided measurement axis system method for determining phase connection, such as... Figure 1 As shown, it includes the following steps:

[0068] S1: T-shaped markings 1 are etched at the input and output ends of the reducer, respectively;

[0069] T-shaped markings are etched on the external spline end faces 4 at both the input and output ends of the reducer. These T-shaped markings have clear horizontal and vertical edges, making them more visually prominent and easier for camera vision measurement systems to capture and identify. In contrast, while the I-shaped marking also has vertical and horizontal structures, its vertical portion is divided into two segments, potentially increasing the complexity and uncertainty during recognition. The edges of the T-shaped markings are more defined, especially during binarization and edge extraction, allowing for more accurate acquisition of the horizontal and vertical edge position information. The edges of the I-shaped marking may become more complex due to segmentation, increasing the difficulty of recognition.

[0070] Furthermore, calculating the angle of a T-shaped marker is relatively simple. The angle with the positive X-axis (zero phase) in the camera coordinate system can be quickly determined using the equations of the horizontal side 2 and the vertical side 3 of the T-shaped marker, reducing errors in angle calculation. In contrast, the I-shaped marker, due to its complex structure, may require more calculation steps and more complex algorithms to determine its angle, potentially introducing more uncertainty and errors in angle calculation.

[0071] Therefore, this application etches T-shaped markings at the input and output ends of the reducer, which helps to improve the accuracy and stability of phase identification.

[0072] However, the dimensions of the T-shaped mark satisfy the following relationship:

[0073] L h= k1×D;

[0074] L v = k2×D, and L v / L h = m; By using the proportional constant m, the shape ratio of the T-shaped sign is controlled to maintain the clarity of the sign and improve the accuracy of camera recognition.

[0075] W = k3×(D / P) n ×D; The influence of tooth pitch on width has been taken into account, so that when the tooth pitch is large, the width of the horizontal side of the T-shaped mark can be appropriately increased to maintain the clarity of the mark.

[0076] |L v - L h |≤ΔL; The length difference threshold ΔL is used to control the shape of the T-shaped sign so that it is not too long or too short or too flat.

[0077] Among them, L h L represents the length of the horizontal side of the T-shaped sign. v The vertical side length of the T-shaped mark is represented by D, the outer diameter of the spline is represented by P, the tooth pitch of the spline is represented by k1, k2, and k3, respectively, the proportional coefficients are represented by m, the proportional constant is represented by n, the exponential factor is represented by W, the horizontal side width of the T-shaped mark is represented by ΔL, and the preset length difference threshold is represented by ΔL.

[0078] Furthermore, the width W of the horizontal side of the T-shaped sign is not less than a preset width threshold W. min Width threshold W min This is the minimum width threshold used to ensure the clarity of the identifier in image recognition.

[0079] In practical applications, it is necessary to determine these proportional coefficients k1, k2, k3, proportional constant (m), exponential factor (n), and minimum width threshold W through experiments and debugging, based on the specific reducer model, measurement system accuracy, and image recognition algorithm requirements. min The specific values ​​for the length difference threshold ΔL are determined. These values ​​should ensure that the T-shaped marker has sufficient clarity and stability in image recognition, while also meeting the accuracy requirements of the measurement system.

[0080] The vision-guided measurement axis system phase connection determination method provided in this application etches T-shaped markings at the input and output ends of the reducer. The horizontal side length, vertical side length, and width of the T-shaped markings are related to the outer diameter and tooth pitch of the spline, which improves the accuracy of camera image recognition and thus improves the assembly precision of the reducer.

[0081] S2: Under the standard connection phase state, the high-speed end measures the shaft phase φ1, and the angle α1 between the horizontal side of the T-shaped mark at the reducer input end and the positive X-axis in the camera coordinate system; the low-speed end measures the shaft phase φ2, and the angle α2 between the horizontal side of the T-shaped mark at the reducer output end and the positive X-axis in the camera coordinate system. The standard connection phase state refers to the state where the high-speed end is connected to the reducer input end and the low-speed end is connected to the reducer output end at the test station. This application first obtains the above angles under the standard connection phase state. These angles are the angles when the high-speed end measuring shaft, reducer, and low-speed end are placed at the test station for assembly.

[0082] It should be noted that the angles obtained in step S2 only need to be calibrated and measured once. When assembling multiple reducers in the future, although the phase of each reducer is placed randomly in the preparation position, it is only necessary to repeat steps S3-S8. The rotation angles of the high-speed and low-speed end shafts are calculated based on the included angles under the same standard connection phase state during each assembly.

[0083] Place the reducer under test in the test position without changing the phase state of the high and low speed end measuring shaft system and the reducer under test. Move the reducer under test and the adapter to a suitable position for camera shooting.

[0084] Furthermore, under standard connection phase conditions, the method for obtaining the angle α1 between the horizontal side of the T-shaped mark at the input end of the reducer and the positive X-axis in the camera coordinate system is as follows:

[0085] The first image is obtained by taking a picture of the T-shaped mark at the input end of the reducer using a camera vision measurement system;

[0086] Identify the edges of the T-shaped marker in the first image, perform binarization processing, obtain the edges of the horizontal and vertical sides of the T-shaped marker, and fit the linear equations of the two sides in the camera coordinate system respectively;

[0087] Select two points A and B on the same side of the vertical edge of the T-shaped sign, and calculate the difference δ between the two points in the Y direction. δ = Y A -Y B The positions of points A and B are shown in the diagram. Figure 3 .

[0088] Based on the slope k and δ of the vertical straight line equation of the T-shaped mark and the acute angle θ between the horizontal side of the T-shaped mark and the positive X-axis direction (zero phase) in the camera coordinate system, determine the angle α1 between the horizontal side of the T-shaped mark at the input end of the reducer and the positive X-axis direction in the camera coordinate system.

[0089] Furthermore, based on the slope k and δ of the vertical straight line equation of the T-shaped marker and the acute angle θ between the horizontal side of the T-shaped marker and the positive X-axis direction (zero phase) in the camera coordinate system, the angle α1 between the horizontal side of the T-shaped marker at the input end of the reducer and the positive X-axis direction in the camera coordinate system is determined as follows:

[0090] If the slope k of the vertical line equation of the T-shaped marker is less than 0 and δ > 0, then α1 = θ;

[0091] If the slope k of the equation of the vertical line of the T-shaped marker is less than 0 and δ < 0, then α1 = 180º + θ;

[0092] If the slope k of the vertical line equation of the T-shaped marker is greater than 0 and δ > 0, then α1 = 360º - θ;

[0093] If the slope k of the vertical line equation of the T-shaped marker is greater than 0 and δ < 0, then α1 = 180º - θ.

[0094] Similarly, under the standard connection phase state, the method for obtaining the angle α2 between the horizontal side of the T-shaped mark at the output end of the reducer and the positive X-axis in the camera coordinate system is the same as α1, and will not be repeated here.

[0095] For example, at test station 16, the reducer and adapter under test are positioned and assembled with the high- and low-speed end measurement systems using a manual adjustment method, and this measurement shaft connection state is taken as the standard connection phase state, such as... Figure 2 As shown. Using the circular grating angle measurement system within the high-speed and low-speed end measurement systems, the phase φ1 of the high-speed end measurement axis and the phase φ2 of the low-speed end measurement axis are recorded. Using the first set of camera vision measurement systems 12 and the second set of camera vision measurement systems 17, the angle α1 between the horizontal side of the T-shaped mark at the reducer input end and the positive X-axis in the camera coordinate system, and the angle α1 between the horizontal side of the T-shaped mark at the reducer output end and the positive X-axis in the camera coordinate system are obtained, respectively. 2。

[0096] S3: Move the high-speed end to the preparatory position and obtain the angle β between the phase γ1 of the high-speed end's measuring axis and the horizontal side of the T-shaped mark at the reducer input end in the camera coordinate system and the positive X-axis direction. 1。

[0097] To enable rapid replacement of the reducer under test, the shaft system is connected using involute splines, including the high-speed measuring shaft system connected to the input end of the reducer under test, and the low-speed measuring shaft system connected to the output end of the reducer under test. During actual assembly, the reducer is placed in a pre-assembly position. The states of the input and output ends are random before assembly, therefore the phase of the external spline connecting to the measuring shaft system is also random.

[0098] like Figure 3As shown, the object to be transported (the reducer and adapter under test) 8 is placed in the preparatory position 14 of the tester to form the component to be tested. The high-speed end, under the movement of the tester guide rail system, carries the first set of camera measurement system 12 to directly above the input shaft of the reducer (directly above the preparatory position 14), and photographs the T-shaped mark on the spline shaft end face of the reducer input end and obtains the angle β1 between the T-shaped mark of the input end spline and the zero phase in the camera coordinate system at this time.

[0099] The specific methods for calculating β1 include:

[0100] A second image is obtained by taking a picture of the T-shaped mark at the input end of the reducer using a camera vision measurement system;

[0101] Identify the edges of the T-shaped marker in the second image, perform binarization processing, obtain the edges of the horizontal and vertical sides of the T-shaped marker, and fit the linear equations of the two sides in the camera coordinate system respectively;

[0102] Select two points A' and B' on the same side of the vertical edge of the T-shaped sign, and calculate the difference δ' between the two points in the Y direction. δ` = Y A `-Y B ` ;

[0103] Based on the slopes k` and δ` of the vertical straight line equation of the T-shaped marker and the acute angle θ` between the horizontal side of the T-shaped marker and the positive X-axis direction (zero phase) in the camera coordinate system, determine the angle β1 between the horizontal side of the T-shaped marker at the input end of the reducer and the positive X-axis direction in the camera coordinate system.

[0104] Furthermore, based on the slopes k` and δ` of the vertical straight line equation of the T-shaped marker and the acute angle θ` between the horizontal side of the T-shaped marker and the positive X-axis direction (zero phase) in the camera coordinate system, the angle β1 between the horizontal side of the T-shaped marker at the input end of the reducer and the positive X-axis direction in the camera coordinate system is determined as follows:

[0105] If the slope k` of the vertical line equation of the T-shaped marker is less than 0 and δ`>0, then β1=θ`;

[0106] If the slope k` of the vertical line equation of the T-shaped marker is less than 0 and δ` < 0, then β1 = 180º + θ`;

[0107] If the slope k` of the vertical line equation of the T-shaped marker is greater than 0 and δ`>0, then β1=360º-θ`;

[0108] If the slope k` of the vertical line equation of the T-shaped marker is greater than 0 and δ` < 0, then β1 = 180º - θ`.

[0109] S4: Calculate the rotation angle Δ1 of the high-speed end measuring shaft system based on γ1, β1, φ1, and α1;

[0110] Furthermore, the formula for calculating the rotation angle Δ1 of the high-speed end measuring shaft system is as follows:

[0111] Δ1= ( γ 1-φ1) - ( β 1- α 1);

[0112] If Δ1 is negative, it indicates that the high-speed end measuring shaft system rotates counterclockwise by the angle |Δ1|.

[0113] If Δ1 is a non-negative value, it indicates that the high-speed end measuring shaft system rotates clockwise by the angle |Δ1|.

[0114] The high-speed end measuring shaft rotates by an angle Δ1, ensuring that the high-speed end measuring shaft and the reducer input shaft are in a phase-aligned state under calibration conditions. Here, (γ1-φ1) represents the phase difference between the high-speed end measuring shaft in its random state (i.e., actual state) and its standard connection phase state. β 1- α 1) is the phase difference between the random state and the standard connection phase state at the input end of the reducer.

[0115] S5: After rotating the high-speed end measuring shaft by Δ1 and connecting it to the input end of the reducer, move it to the test station 16; the high-speed end is positioned and connected to the input side of the reducer adapter under the drive of the guide rail system 15, and is pressed together and in a non-separated state, and then moved to the test station 16.

[0116] S6: Obtain the phase γ2 of the low-speed end measurement axis in the camera coordinate system, and the angle β2 between the horizontal side of the T-shaped mark at the reducer output end and the positive X-axis in the camera coordinate system.

[0117] Similarly, the calculation method for β2 is the same as that for β1, and will not be repeated here.

[0118] S7: Calculate the rotation angle Δ2 of the low-speed end measuring shaft system based on γ2, β2, φ2, and α2;

[0119] Furthermore, the formula for calculating the rotation angle Δ2 of the shaft system at the low-speed end is as follows:

[0120] Δ2= ( γ 2-φ2) - ( β 2- α 2).

[0121] If Δ2 is negative, it indicates that the high-speed end measuring shaft system rotates counterclockwise by the angle |Δ2|.

[0122] If Δ2 is a non-negative value, it represents the clockwise rotation angle |Δ2| of the high-speed end measuring shaft system.

[0123] S8: Rotate the low-speed end measuring shaft by Δ2 and connect it to the output end of the reducer to complete the phase connection.

[0124] The guide rail moving system 15 drives the high-speed end and the transported object (the reducer and adapter under test) 8 to move to the test station 16 and position and clamp it with the low-speed end measuring component to realize the phase connection process of the measuring axis system.

[0125] The high-speed end, which has rotatable power, is moved from the testing station to the preparation station for assembly with the input end of the reducer. Since the reducer and its connecting parts do not have rotational power, the high-speed end shaft is rotated for assembly. The assembled high-speed end and reducer are then moved back to the testing station to obtain the rotation angle of the low-speed end shaft before rotating the low-speed end to complete the entire assembly process.

[0126] Furthermore, the slots at the high-speed end, the splines at the input end of the reducer, the slots at the low-speed end, and the splines at the output end of the reducer are numbered respectively.

[0127] When the high-speed end is connected to the input end of the reducer, the slot number of the high-speed end is consistent with the spline number of the input end of the reducer: for example, slot 1 of the high-speed end is connected to spline 1 of the input end of the reducer, slot 2 of the high-speed end is connected to spline 2 of the input end of the reducer, and so on.

[0128] When the low-speed end is connected to the output end of the reducer in phase, the slot number of the low-speed end is consistent with the spline number of the output end of the reducer. For example, slot 1 of the low-speed end is connected to spline 1 of the output end of the reducer, slot 2 of the low-speed end is connected to spline 2 of the output end of the reducer, and so on.

[0129] After the reducer is assembled, it may be necessary to test the assembly accuracy and perform calibration after inspection. Since spline connections inevitably have clearances, and the connection of different numbered internal and external spline teeth and spline slots (i.e., the connection of the measuring shaft system under different phases) results in inconsistent angular measurement error clearances, this causes inconvenience for angular measurement error compensation. Furthermore, if the shaft connection phases are inconsistent, the measurement state of the reducer under test will differ each time. Therefore, it is necessary to implement a "name system" for the teeth and slots of the internal and external splines. That is, when the high-speed end is connected to the reducer input end, the slot number of the high-speed end must match the spline tooth number of the reducer input end; when the low-speed end is connected to the reducer output end, the slot number of the low-speed end must match the spline tooth number of the reducer output end. This ensures the connection under a specific phase and achieves the uniqueness of the measuring shaft system connection. By ensuring the uniqueness of the connection state between the measuring shaft system in the instrument and the input and output measuring shafts of the reducer under test, the spline tooth and slot clearance is determined and unique in each assembly and disassembly process, further ensuring the accuracy of the measured parameters of the reducer under test.

[0130] The phase of the internal spline in the measurement system is fixed relative to the phase of the circular grating angle measurement system. Therefore, an additional measurement method is needed to correlate the phase of the external spline with that of the internal spline. The transmission effect produced by the engagement of the internal and external teeth differs under different phases, with significant differences in its impact on angle measurement accuracy, especially given the presence of transmission backlash. Therefore, it is necessary to "name" the internal and external splines to ensure the uniqueness of the shaft connection under specific phases.

[0131] In this application, the shaft phase is measured at high speed under standard and actual conditions. 、 The technical solution for determining the rotation angles of the high-speed and low-speed measuring shaft systems, based on the angle between the horizontal side of the T-shaped mark at the input end of the reducer and the positive X-axis in the camera coordinate system, is not limited to spline connections. Theoretically, it can also be applied to assemblies with other connection methods.

[0132] It should be noted that the terminology used in this application is for the purpose of describing specific embodiments only and is not intended to limit the scope of this application. As shown in this specification, unless the context clearly indicates otherwise, words such as "a," "an," "an," and / or "the" do not specifically refer to the singular and may include the plural. The terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element.

[0133] It should also be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," "linked," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of this application.

Claims

1. A method for determining phase connection of a measurement axis system based on vision guidance, characterized in that, Includes the following steps: S1: T-shaped markings are etched at the input and output ends of the reducer, respectively; the dimensions of the T-shaped markings satisfy the following relationship: L h = k1×D; L v = k2×D, and L v / L h = m; W = k3×(D / P) n ×D; |L v - L h |≤ΔL; Among them, L h L represents the length of the horizontal side of the T-shaped sign. v The vertical side length of the T-shaped mark is represented by D, the outer diameter of the spline is represented by P, the tooth pitch of the spline is represented by k1, k2, and k3, respectively, the proportional coefficients are represented by m, the proportional constant is represented by n, the exponential factor is represented by W, the horizontal side width of the T-shaped mark is represented by ΔL, and the preset length difference threshold is represented by ΔL. S2: Under the standard connection phase state, measure the shaft phase φ1 at the high speed end, and the angle α1 between the horizontal side of the T-shaped mark at the input end of the reducer and the positive X-axis in the camera coordinate system. Measure the shaft phase φ2 at the low speed end, and the angle α2 between the horizontal side of the T-shaped mark at the output end of the reducer and the positive X-axis in the camera coordinate system. Under standard connection phase conditions, the method for obtaining the angle α1 between the horizontal side of the T-shaped mark at the input end of the reducer and the positive X-axis in the camera coordinate system is as follows: The first image is obtained by taking a picture of the T-shaped mark at the input end of the reducer using a camera vision measurement system; Identify the edges of the T-shaped marker in the first image, perform binarization processing, obtain the edges of the horizontal and vertical sides of the T-shaped marker, and fit the linear equations of the two sides in the camera coordinate system respectively; Select two points A and B on the same side of the vertical edge of the T-shaped mark, and calculate the difference δ between the two points in the Y direction; Based on the slope k and δ of the vertical straight line equation of the T-shaped marker and the acute angle θ between the horizontal side of the T-shaped marker and the positive X-axis in the camera coordinate system, determine the angle α1 between the horizontal side of the T-shaped marker at the input end of the reducer and the positive X-axis in the camera coordinate system; specifically including: If the slope k of the vertical line equation of the T-shaped marker is less than 0 and δ > 0, then α1 = θ; If the slope k of the equation of the vertical line of the T-shaped marker is less than 0 and δ < 0, then α1 = 180º + θ; If the slope k of the vertical line equation of the T-shaped marker is greater than 0 and δ > 0, then α1 = 360º - θ; If the slope k of the vertical line equation of the T-shaped marker is greater than 0 and δ < 0, then α1 = 180º - θ; S3: Move the high-speed end to the preparatory position and obtain the angle β1 between the phase γ1 of the high-speed end measurement axis and the horizontal side of the T-shaped mark at the input end of the reducer and the positive direction of the X-axis in the camera coordinate system. S4: Calculate the rotation angle Δ1 of the high-speed end measuring shaft system based on γ1, β1, φ1, and α1; S5: After rotating the high-speed end measuring shaft by Δ1 and connecting it to the input end of the reducer, move it to the test station; S6: Obtain the phase γ2 of the low-speed end measurement axis in the camera coordinate system, and the angle β2 between the horizontal side of the T-shaped mark at the reducer output end and the positive X-axis in the camera coordinate system. S7: Calculate the rotation angle Δ2 of the low-speed end measuring shaft system based on γ2, β2, φ2, and α2; S8: Rotate the low-speed end measuring shaft by Δ2 and connect it to the output end of the reducer to complete the phase connection.

2. The method for determining phase connection of a measurement axis system based on vision guidance according to claim 1, characterized in that, The formula for calculating the rotation angle Δ1 of the shaft system at the high-speed end is: Δ1= ( γ 1-φ1) - ( β 1- α 1); If Δ1 is negative, it indicates that the high-speed end measuring shaft system rotates counterclockwise by the angle |Δ1|. If Δ1 is a non-negative value, it indicates that the high-speed end measuring shaft system rotates clockwise by the angle |Δ1|.

3. The method for determining phase connection of a measurement axis system based on vision guidance according to claim 1, characterized in that, The formula for calculating the rotation angle Δ2 of the shaft system at the low speed end is: Δ2= ( γ 2-φ2) - ( β 2- α 2); If Δ2 is negative, it indicates that the measuring shaft system at the low speed end rotates counterclockwise by the angle |Δ2|. If Δ2 is a non-negative value, it indicates that the measuring shaft system at the low speed end rotates clockwise by the angle |Δ2|.

4. The method for determining phase connection of a measurement axis system based on vision guidance according to claim 1, characterized in that, In the camera coordinate system, the angle β1 between the horizontal side of the T-shaped mark at the input end of the reducer and the positive X-axis includes: A second image is obtained by taking a picture of the T-shaped mark at the input end of the reducer using a camera vision measurement system; Identify the edges of the T-shaped marker in the second image, perform binarization processing, obtain the edges of the horizontal and vertical sides of the T-shaped marker, and fit the linear equations of the two sides in the camera coordinate system respectively; Select two points A' and B' on the same side of the vertical edge of the T-shaped mark, and calculate the difference δ' between the two points in the Y direction; Based on the slopes k` and δ` of the vertical straight line equation of the T-shaped marker and the acute angle θ` between the horizontal side of the T-shaped marker and the positive X-axis in the camera coordinate system, determine the angle β1 between the horizontal side of the T-shaped marker at the input end of the reducer and the positive X-axis in the camera coordinate system.

5. The method for determining phase connection of a measurement axis system based on vision guidance according to claim 4, characterized in that, Based on the slopes k` and δ` of the vertical straight line equation of the T-shaped marker and the acute angle θ` between the horizontal side of the T-shaped marker and the positive X-axis in the camera coordinate system, the angle β1 between the horizontal side of the T-shaped marker at the input end of the reducer and the positive X-axis in the camera coordinate system is determined as follows: If the slope k` of the vertical line equation of the T-shaped marker is less than 0 and δ`>0, then β1=θ`; If the slope k` of the vertical line equation of the T-shaped marker is less than 0 and δ` < 0, then β1 = 180º + θ`; If the slope k` of the vertical line equation of the T-shaped marker is greater than 0 and δ`>0, then β1=360º-θ`; If the slope k` of the vertical line equation of the T-shaped marker is greater than 0 and δ` < 0, then β1 = 180º - θ`.

6. The method for determining phase connection of a measurement axis system based on vision guidance according to claim 1, characterized in that, Also includes: Number the slots at the high-speed end, the splines at the input end of the reducer, the slots at the low-speed end, and the splines at the output end of the reducer, respectively. When the high-speed end is connected to the input end of the reducer in phase, the slot number of the high-speed end is consistent with the number of the spline teeth of the input end of the reducer. When the low-speed end is connected to the output end of the reducer in phase, the slot number of the low-speed end is consistent with the number of the spline tooth of the output end of the reducer.

7. The method for determining phase connection of a measurement axis system based on vision guidance according to claim 1, characterized in that, The horizontal width W of the T-shaped sign shall not be less than the preset width threshold W. min .

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