A three-coordinate position detection method and system

Abstract

The present application relates to the technical field of wheel hub bolt hole detection, and in particular to a three-coordinate position detection method and system, the method comprising: combining manual point taking and central axis hole to establish a detection coordinate system; collecting bolt hole data; calculating the position and coordinate deviation of the bolt hole; if the position deviation of all bolt holes is less than or equal to the first set allowable threshold, and the absolute value of the aperture deviation of all bolt holes is less than or equal to the second set allowable threshold, the output is qualified, otherwise, if any bolt hole aperture deviation is greater than the second set allowable threshold and / or any bolt hole position deviation is greater than the first set upper limit threshold, it is handed over to the staff for processing, otherwise, turning correction is performed. The system comprises a benchmark establishment module, a center calibration module, a dynamic measurement point allocation module, a position calculation module, a compensation decision module, a coordinate system recalibration module, a true roundness detection module, a collaborative finishing module and a turning control module. The present application has the effect of reducing the distortion of the bolt hole position.

Description

Technical Field

[0001] The present application relates to the technical field of wheel hub bolt hole position detection, and in particular to a three-coordinate position detection method and system. Background Art

[0002] Currently, the wheel hub manufacturing industry widely uses three-dimensional coordinate measuring machines (CMMs) to inspect the position of multiple holes. Traditionally, four reference points are manually selected on the wheel hub end face. The CMM then establishes a coordinate system based on these reference points, automatically identifying the coordinates of the five bolt holes and the center bearing hole. Four points are measured evenly spaced around each hole, and the deviation between the measured coordinates and the theoretical design coordinates is calculated to determine product conformity. If the deviation exceeds the specified limit, the part is either partially repaired or scrapped.

[0003] In the prior art, a Chinese patent with publication number CN115060212A discloses a spiral groove measurement method, which manually measures and establishes a rough reference coordinate system of the workpiece plane using a three-coordinate measuring machine. The three-coordinate measuring machine then automatically measures the workpiece plane based on the rough reference coordinate system and establishes a fine reference coordinate system. The spiral groove is then multi-point detected and the position accuracy of each spiral groove detection is calculated.

[0004] It realizes the automated measurement of spiral grooves through the conversion of coarse / fine reference coordinate systems. However, in wheel hub inspection, the relative position accuracy of the center hole and the bolt hole directly affects the assembly performance. The deviation of the reference coordinate system or the failure to consider the center hole can easily lead to a mismatch between the bolt hole position and the center hole position, resulting in distortion of the bolt hole position and affecting the subsequent turning and trimming of the bolt hole, leading to repeated trimming or even scrapping. Summary of the Invention

[0005] The present application provides a three-coordinate position detection method and system, which can at least partially solve the above technical problems.

[0006] In the first aspect, the present application provides a three-coordinate position detection method, which adopts the following technical solution:

[0007] A three-coordinate position detection method comprises the following steps:

[0008] Manual point selection: Manually select four points on the hub end face as reference points, and establish the initial three-coordinate system with the four reference points;

[0009] Center point acquisition: Control the probe to evenly collect data from multiple points on the central axis hole as calibration points. Use multiple calibration points to determine the center of the central axis hole, and combine them with the initial coordinate system to establish the detection coordinate system.

[0010] Bolt hole collection: collect data at 4 points evenly around the circumference of each bolt hole;

[0011] Position calculation: calculate the coordinates of multiple bolt holes, calculate the position, and calculate the coordinate deviation of each bolt hole based on the theoretical coordinates;

[0012] Deviation judgment: If the position deviations of all bolt holes are less than or equal to the first set allowable threshold, and the absolute values ​​of the diameter deviations of all bolt holes are less than or equal to the second set allowable threshold, the output is qualified. Otherwise, the over-limit judgment step is executed;

[0013] Over-limit judgment: If the diameter deviation of any bolt hole is greater than the second set allowable threshold and / or the position deviation of any bolt hole is greater than the first set upper limit threshold, the scrapping step is triggered; otherwise, the compensation step is executed;

[0014] Compensation: According to the coordinate deviation of the bolt hole, the lathe performs turning correction;

[0015] Scrap: The wheel hub has irreparable hole defects and will be handed over to staff for subsequent processing.

[0016] By adopting the above technical solution, the reference point is manually determined to establish an initial coordinate system, and then a point is taken at the center axis hole, combined with the initial coordinate system, to establish a detection coordinate system, and then a probe test is performed on the bolt hole to detect the coordinates of the bolt hole and calculate the position. The coordinate deviation of the bolt hole is calculated in combination with the theoretical coordinates, and then it is determined whether it needs to be qualified, and whether the unqualified one needs to be corrected or scrapped; the detection coordinate system is established through the center hole calibration point to ensure that the bolt hole position is based on the center hole, solving the assembly deviation caused by ignoring the center hole in the traditional method; the coordinate system is formed with the assistance of the center hole to reduce the mismatch between the bolt hole position and the center hole position, reduce the distortion of the bolt hole position, and reduce the impact on the subsequent bolt hole turning and trimming, which leads to repeated trimming or even scrapping; the over-limit judgment layered mechanism (allowable threshold, upper limit threshold) reduces false rejections, and the compensation step reduces rework costs.

[0017] Optionally, in the center point selection step:

[0018] The number of collection points is ≥6;

[0019] When the measured center of the center hole With the theoretical center Offset When , the coordinate system recalibration is triggered:

[0020] by Reconstruct the detection coordinate system for the origin;

[0021] According to the formula , the corrected bolt hole theoretical coordinates are , where k is the bolt hole number.

[0022] By adopting the above technical solution, when the center hole offset is greater than 0.05mm, the coordinate system is rebuilt with the measured center O' to avoid the reference transfer error; the theoretical coordinate correction formula compensates for the systematic offset, so that the bolt hole position calculation is closer to the actual assembly state, and then probe detection is performed, which can improve the accuracy of detection, reduce errors, and reduce error transmission, thereby reducing the production of unqualified products or reducing the production of unqualified products caused by further processing.

[0023] Optionally, the bolt hole collection step includes dynamic measurement point allocation:

[0024] Get the center hole offset angle ;

[0025] exist The number of measurement points for bolt holes within the interval is increased to 6;

[0026] The remaining bolt holes maintain 4 measuring points.

[0027] By adopting the above technical solution, the number of bolt hole measuring points is increased to 6 within the range of ±30° in the center hole offset direction, thereby improving the detection accuracy in high stress areas; 4 measuring points are maintained in the remaining areas to balance efficiency and accuracy; by obtaining the offset direction of the center hole (a reasonable offset within the specification), the detection points for the bolt hole detection probe are enhanced to better detect the actual situation of the corresponding bolt hole, thereby improving detection accuracy and reducing the possibility of undetected bolt hole position offset.

[0028] Optionally, after the coordinate system recalibration is triggered, a center hole roundness detection step is added: ≥12 measuring points are evenly collected around the circumference of the center hole;

[0029] Calculate each measuring point to The radial distance set ;

[0030] If the radial distance standard deviation , determine that the center hole is unevenly turned and perform center hole compensation: identify the three points with the largest distance deviation and generate a correction vector group;

[0031] Output center hole turning amount: .

[0032] By adopting the above technical solution, the coordinate system is recalibrated and 12-point roundness detection is added to identify uneven turning of the center hole ( The turning amount Δr is calculated based on the maximum radial deviation, and the correction amount is limited to ≤0.15mm to prevent over-cutting. The above calibration facilitates targeted detection of the actual situation of the center hole, and then the center hole is trimmed according to the actual situation, while reducing the amount of trimming, improving efficiency, and facilitating the subsequent accurate detection of the bolt hole position.

[0033] Optionally, the turning path for center hole compensation is: As the center of the circle, a non-uniform turning trajectory is generated according to the correction vector group; the maximum turning depth is located at the point with the maximum distance deviation, and the depth is distributed according to Δr×(1+cosθ);

[0034] The turning path of the center hole compensation satisfies the hub assembly constraints:

[0035] Turning depth control: maximum turning depth satisfy: ;

[0036] Continuous gradient requirement: The turning depth function is: ;in, Indicates the circumference angle, is the maximum deviation direction angle;

[0037] Verification: Perform a roundness recheck after turning.

[0038] By adopting the above technical solution, non-constant depth turning trajectories can be accurately corrected for deformed areas; combined with assembly requirements, the turning depth is limited to less than or equal to 30% of the designed interference to ensure assembly strength; virtual interference simulation verifies assembly feasibility in advance and reduces the possibility of secondary scrap.

[0039] Optionally, the compensation step further includes: when only the position deviation of a single bolt hole is less than or equal to a first set upper limit threshold, performing collaborative trimming: adjusting the position of multiple bolt holes at the same time to achieve multi-hole collaborative offset compensation.

[0040] By adopting the above technical solution, when a single bolt hole exceeds the limit, all the bolt holes are corrected, reducing the excessive excess of a single hub, and remedying it by correcting other holes, thereby reducing the possibility of hub scrapping, and at the same time reducing the scrapping caused by a single bolt hole exceeding the limit, thereby improving resource utilization.

[0041] Optionally, the compensation step further includes:

[0042] If the angle difference of all bolt hole coordinate deviations is less than or equal to the angle deviation threshold, and the deviation mean μ>0.1mm, and the deviation vector synthesis modulus length >0.9, it is judged as overall offset;

[0043] Then perform center offset verification and measure the radial runout of the hub mounting surface ;

[0044] like , then execute the correction of the center hole position ,in is the deviation direction unit vector, is the compensation coefficient;

[0045] like , then no center hole correction is performed;

[0046] Then with Re-execute bolt hole collection and position calculation as the benchmark.

[0047] By adopting the above technical solution, the overall offset is determined by the consistency of the deviation direction angle, the mean value and the synthetic modulus length of the deviation vector; the radial runout verification: if (such as 0.1mm), correct the center hole position, solve the batch tolerance caused by the eccentricity of the installation surface, reduce the chance of false rejection, improve the detection accuracy, and reduce the waste of resources caused by scrapping.

[0048] Optionally, in the center point selection step, the measurement points are collected using a spiral progressive path:

[0049] Measuring point height coordinates: , where H is the center hole height, j=1, 2, ..., M;

[0050] Angular coordinates: ;when When the axial bending detection is triggered: calculate the center offset of each height layer , Represents the average center of each altitude layer, if If the maximum value is greater than the preset maximum allowable eccentricity value, it is determined that the axis of the center hole is bent.

[0051] By adopting the above technical solution, the bending of the center hole may cause distortion in the establishment of the coordinate system and distortion in the detection of the bolt hole position. Through this detection method, it is possible to preliminarily determine whether there is a benchmark error and then decide whether to continue with subsequent detection, thereby reducing waste of resources.

[0052] Optionally, when the central hole axis is determined to be curved, the curvature gradient is calculated: ,

[0053] like When the gradient threshold is less than or equal to the value, the turning amount is corrected. Otherwise, execute the scrapping steps.

[0054] By adopting the above technical solution, the progressive acquisition path can realize axial multi-layer scanning, and the center offset When the value is greater than the threshold, the axis is judged to be curved, and the gradient If the limit is exceeded, it will be scrapped, which reduces unnecessary compensation and repairs and reduces waste of resources.

[0055] In a second aspect, the present application provides a system that adopts the following technical solutions:

[0056] A system includes the following modules:

[0057] Datum establishment module: used to manually select four points on the hub end face to establish the initial three-coordinate system;

[0058] Center calibration module: The input end is connected to the output end of the reference establishment module for electrical signal connection. The probe is controlled to uniformly collect data from multiple points in the central axis hole, calculate the measured center of the circle, and compare it with the theoretical center of the circle.

[0059] Dynamic measuring point allocation module: The input end is connected to the output end of the center calibration module for electrical signal connection, and the number of measuring points of the bolt hole is adjusted according to the offset direction angle of the center hole;

[0060] Position calculation module: The input end is connected to the output end electrical signal of the dynamic measurement point allocation module to calculate the coordinate deviation of each bolt hole and trigger the over-limit judgment based on the set threshold;

[0061] Compensation decision module: The input end is connected to the electrical signal of the output end of the position calculation module. When the bolt hole deviation is greater than the allowable threshold but less than or equal to the upper threshold, a turning correction instruction is generated; when the deviation is greater than the upper threshold, a scrapping instruction is triggered;

[0062] Coordinate system recalibration module: The input end is connected to the output end of the center calibration module. When the measured center of the circle deviates greatly from the theoretical center of the circle, the detection coordinate system is rebuilt with the measured center of the circle as the origin, and the theoretical coordinates of the bolt hole are corrected.

[0063] Roundness detection module: The input end is connected to the output end of the coordinate system recalibration module. After the coordinate system is recalibrated, multiple measurement points are collected at the center hole to calculate the radial distance standard deviation.

[0064] Collaborative finishing module: The input end is connected to the electrical signal of the output end of the position calculation module. When a single bolt hole exceeds the limit, the turning plan is optimized with the global minimum turning amount as the goal;

[0065] Turning control module: The input end is connected to the output end of the supplementary decision module and performs turning operations according to the compensation instructions.

[0066] By adopting the above technical solution, the dynamic measuring point allocation module receives the center hole offset angle and adjusts the number of bolt hole measuring points in real time; the compensation decision module is linked to the turning control module to output non-equal depth turning instructions; the roundness detection module and the collaborative dressing module are combined to reduce the scrap rate of single-hole over-limit wheels, and through the cooperation of multiple modules, the probe detection of bolt hole position is realized.

[0067] In summary, this application includes at least one of the following beneficial technical effects:

[0068] 1. The center hole assists in forming a coordinate system, reducing mismatches between bolt hole positions and center hole positions, reducing bolt hole position distortion, and minimizing the impact on subsequent bolt hole turning and trimming, which can lead to repeated trimming or even scrap. A hierarchical mechanism for over-limit judgment (allowable threshold and upper threshold) reduces false rejections, and compensation steps reduce rework costs.

[0069] 2. Non-constant depth turning trajectories allow for precise correction of deformation areas. Based on assembly requirements, the turning depth is limited to 30% or less of the designed interference to ensure assembly strength. Virtual interference simulation verifies assembly feasibility in advance, reducing the possibility of secondary scrap.

[0070] 3. When a single bolt hole exceeds the limit, all bolt holes will be corrected to reduce the excessive excess of a single hub. The correction of other holes can be used to remedy the situation, reduce the possibility of hub scrapping, and at the same time reduce the scrapping caused by a single bolt hole exceeding the limit, thereby improving resource utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 It is a flow chart of the coordinate position detection method in an embodiment of the present application. DETAILED DESCRIPTION

[0072] The following combination Figure 1 This application is described in further detail.

[0073] This embodiment discloses a three-coordinate position detection method.

[0074] Example 1: Reference Figure 1 , a three-coordinate position detection method includes the following steps:

[0075] Manual point selection: Manually select four points on the hub end face as reference points, and establish the initial three-coordinate system with the four reference points;

[0076] Specifically, the operator uses the stylus of a coordinate measuring machine (CMM) and manually adjusts the remote control to manually select four non-collinear points on the wheel hub end face (usually located on the wheel hub mounting surface), which are recorded as to .

[0077] Coordinate system establishment: Use the least squares method to fit the plane equation Ax + By + Cz + D = 0 to determine the reference plane;

[0078] by The connecting line is the X-axis direction, the plane normal vector is the Z-axis, and the initial coordinate system is established. (The origin is the centroid of the four points);

[0079] Center point acquisition: Control the probe to evenly collect data from multiple points on the central axis hole as calibration points. Use multiple calibration points to determine the center of the central axis hole, and combine them with the initial coordinate system to establish the detection coordinate system.

[0080] Specifically, the control probe uniformly collects n points (usually n ≥ 4) on the inner wall of the central axis hole. In this embodiment, 4 points are preferably collected, which are recorded as , i=1, 2, ..., n; coordinates of the center of the fitting center hole : ;

[0081] Detection coordinate system establishment: with the center of the center hole As the new origin, the reference plane normal vector is the Z axis, the initial X axis direction is rotated and aligned, and the final detection coordinate system is established ;

[0082] Bolt hole collection: collect data at 4 points evenly around the circumference of each bolt hole;

[0083] Specifically, for each bolt hole, four points (0°, 90°, 180°, and 270°) are evenly distributed around the hole wall and recorded as ,in, (indicates the hole number), (indicates the measuring point number);

[0084] Bolt hole center coordinates : ;

[0085] Position calculation: calculate the coordinates of multiple bolt holes, calculate the position, and calculate the coordinate deviation of each bolt hole based on the theoretical coordinates;

[0086] Specifically, the position deviation of the kth hole is , ,in, , ; Radial deviation , angular deviation ;

[0087] Aperture deviation : ,in ,in Indicates the distance from the measuring point to the center of the bolt hole;

[0088] Deviation judgment: If the position deviations of all bolt holes are less than or equal to the first set allowable threshold, and the absolute values ​​of the diameter deviations of all bolt holes are less than or equal to the second set allowable threshold, the output is qualified. Otherwise, the over-limit judgment step is executed;

[0089] Specifically, the first setting permission threshold It can be adjusted according to the size of the bolt hole and the reference standard. The larger the bolt hole, the larger the first setting threshold. It is related to the hub load level. The higher the load level, the smaller the value. The second setting threshold , can be adjusted according to the size of the bolt hole combined with the reference standard. The larger the bolt hole, the greater the second setting allowable threshold; when the position deviation of all bolt holes is less than or equal to , and the absolute value of the diameter deviation of all bolt holes Less than or equal to , then it is a qualified product, otherwise, the out-of-limit judgment step is executed.

[0090] Over-limit judgment: If the diameter deviation of any bolt hole is greater than the second set allowable threshold and / or the position deviation of any bolt hole is greater than the first set upper limit threshold, the scrapping step is triggered; otherwise, the compensation step is executed;

[0091] Specifically, the first upper limit threshold is set It can be adjusted according to the size of the bolt hole in combination with the reference standard. The larger the bolt hole, the larger the first set upper limit threshold, which is related to the yield strength of the hub material. The thicker the hub, the larger the value. When any bolt hole diameter deviation is greater than the second set allowable threshold (that is, the measured bolt hole diameter is much larger than the theoretical value), it is an unqualified product and the scrapping step is executed; when any bolt hole position deviation is greater than the first set upper limit threshold, it is an unqualified product and the scrapping step is executed; otherwise, the compensation step is executed.

[0092] Compensation: According to the coordinate deviation of the bolt hole, the lathe performs turning correction;

[0093] Specifically, the lathe is operated according to the deviation vector Fine-tune the hole position and expand the hole to the theoretical diameter .

[0094] Scrap: The wheel hub has irreparable hole defects and will be handed over to staff for subsequent processing.

[0095] For example, wheel parameters: wheel model: 18×8J PCD 5×114.3, bolt hole theoretical positions (detection coordinate system): (0, 50.0), (49.2, 15.4), (30.4, -40.4), (-30.4, -40.4), (-49.2, 15.4) (unit: mm); hole diameter theoretical value: ;

[0096] The test data and calculations are shown in Table 1 below:

[0097] Table 1 Test data

[0098]

[0099] Deviation judgment: If the position deviations of all bolt holes are greater than the first set allowable threshold, the qualification condition is not met and the process enters the over-limit judgment step;

[0100] Over-limit judgment: The aperture deviation of bolt hole 3 is greater than the second set allowable threshold, and the position deviations of bolt holes 1-4 are all greater than the first set upper limit threshold, which triggers both aperture over-tolerance and position serious over-tolerance, and executes the scrapping step.

[0101] Scrap analysis: Aperture out of tolerance: The measured aperture of hole 3 is 14.12mm, which is greater than the upper limit of 14.10mm; Position out of tolerance: The deviation direction angle of hole 3 , radial deviation 0.361mm, the actual hole center exceeds the theoretical position tolerance zone ;Handling: The wheel hub is handed over to the quality inspector and marked as "hole position out of tolerance and cannot be repaired", and enters the scrap recycling process.

[0102] Example 2: The difference from Example 1 is that in the center point selection step:

[0103] The number of collection points is ≥6;

[0104] When the measured center With the theoretical center Offset When , the coordinate system recalibration is triggered:

[0105] by Reconstruct the detection coordinate system for the origin;

[0106] According to the formula , the corrected bolt hole theoretical coordinates are ,in Number the bolt holes.

[0107] The bolt hole collection step includes dynamic measurement point allocation: defining the center hole offset direction angle ;exist For bolt holes within the interval, the number of measuring points is increased to 6; the remaining bolt holes remain at 4 measuring points.

[0108] Specifically, control the CMM probe to collect n ≥ 6 points (preferably 8 points, 45° apart) on the inner wall of the central axis hole, and fit the measured center coordinates :

[0109] ;

[0110] Calculate the center hole offset:

[0111] ;

[0112] in, represents the theoretical center of the circle;

[0113] when When , the detection coordinate system is rebuilt and the new origin is , Z axis: normal vector of the reference plane (same as the initial coordinate system); X axis: the initial X axis is rotated around the Z axis by an angle a to align, ;

[0114] Correction of bolt hole theoretical coordinates: The coefficient of 0.7 is set based on the sensitivity coefficient of the hub bolt hole position to the center offset (obtained through finite element analysis, the transmission rate is 70%).

[0115] Specifically, ;

[0116] For each bolt hole k, calculate its theoretical position angle: ;

[0117] Number of measuring points: ;

[0118] The measuring point allocation angle is distributed at equal intervals around the circumference. The basis for setting the 30° interval is: the sector area where the center hole offset has the greatest impact on the position of the adjacent bolt holes (verified by vibration testing).

[0119] Position calculation: for bolt hole k measuring points :

[0120] ;

[0121] Position deviation: ;

[0122] Angle deviation: .

[0123] In other embodiments, after the coordinate system recalibration is triggered, a center hole roundness detection step is added: ≥12 measurement points are evenly collected around the circumference of the center hole;

[0124] Calculate each measuring point to The radial distance set ;

[0125] If the distance standard deviation , determine that the center hole is unevenly turned and perform center hole compensation: identify the three points with the largest distance deviation and generate a correction vector group;

[0126] Output center hole turning amount: .

[0127] Specifically, the number of measuring points is preferably 16. By increasing the measuring points, the true situation of the center hole is clearly displayed, and by calculating the radial distance and setting the distance standard deviation threshold, the possibility of the center hole having problems can be screened; wherein, , ;

[0128] Generation of correction vector set: Identification of the point of maximum deviation: , generate the correction vector group , (j=1, 2, 3), where express Point the unit vector to the measured point and calculate the turning amount.

[0129] in The setting of 0.02mm is determined according to the standard specifications. In the calculation formula of the center hole turning amount, the setting of 0.8 reserves a safety margin of 0.2 to reduce excessive cutting; 0.15mm is the maximum allowable cutting amount for the interference fit of the hub center hole.

[0130] For example, wheel parameters: Vehicle type: Commercial vehicle wheel hub (6-level load), center hole design radius: , measured center of circle: , some test data are shown in Table 2 below:

[0131] Table 2 Data of measuring points of center hole

[0132]

[0133] Standard Deviation: , , compensation is required, and the maximum point of identification deviation is: 180° direction: , 270° direction deviation is 0.22, 90° direction deviation is 0.18, correction vector group: measuring point angle 180°, ; Measuring point angle 270°, ; Measuring point angle 90°, ; Turning amount calculation: .

[0134] The turning path of the center hole compensation is: As the center of the circle, a non-uniform turning trajectory is generated according to the correction vector group; the maximum turning depth is located at the point with the maximum distance deviation, and the depth is distributed according to Δr×(1+cosθ);

[0135] The turning path of the center hole compensation satisfies the hub assembly constraints:

[0136] Turning depth control: maximum turning depth satisfy: ;

[0137] Continuous gradient requirement: The turning depth function is: ;in, Indicates the circumference angle, is the maximum deviation direction angle;

[0138] Verification: Perform a roundness recheck after turning.

[0139] Specifically, for example, if the maximum deviation angle is 55°, , the design interference is 0.4mm, the design radius is 150mm, then the calculated safety depth is ; The turning depth function is: , the maximum cutting amount is 0.12mm.

[0140] In other embodiments, when only a single bolt hole position deviation is less than or equal to the first set upper limit threshold , greater than the first set allowable threshold When performing collaborative trimming: the position of multiple bolt holes is adjusted simultaneously to achieve multi-hole collaborative offset compensation:

[0141] Calculate the machining allowance of this single bolt hole, , ;

[0142] Coordinated adjustment solution: Objective: Minimize the total adjustment ;

[0143] Constraints: Bias compensation equation: ,satisfy ; Adjust the border: ; Directional coupling coefficient: ,in, is the deviation vector of hole i, represents the position adjustment vector of hole j, represents the polar angle of hole j in the hub coordinate system;

[0144] Correction position for turning hole j: new center coordinate = original center coordinate + ;Synchronous expansion of aperture: ,in, .

[0145] The compensation step further comprises:

[0146] If the angle difference of all bolt hole coordinate deviations is less than or equal to the angle deviation threshold (10°) and the deviation mean μ>0.1mm, and the deviation vector composite modulus length >0.9, it is judged as overall offset;

[0147] Then perform center offset verification and measure the radial runout of the hub mounting surface ;

[0148] like , then execute the correction of the center hole position ,in is the unit vector of the deviation direction, K is the compensation coefficient;

[0149] like , then no center hole correction is performed;

[0150] Then with Re-execute bolt hole collection and position calculation as the benchmark.

[0151] Specifically, the angle deviation threshold is set to 10°, the value of a is 0.2 mm, and the value of the compensation coefficient K is 0.8 (to reduce the safety factor of overcorrection);

[0152] For example, wheel hub parameters: Model: Commercial Vehicle 22.5×10.00 (Load Level 8); PCD: 8×200 mm; Bolt hole diameter: φ22.0±0.1 mm; Center hole theoretical center ; Theoretical coordinates of bolt holes: bolt hole 1 (0, 100), bolt hole 2 (70.71, 70.71), bolt hole 3 (100, 0), bolt hole 4 (70.71, -70.71), bolt hole 5 (0, -100), bolt hole 6 (-70.71, -70.71), bolt hole 7 (-100, 0), bolt hole 8 (-70.71, 70.71).

[0153] The test data is shown in Table 3 below:

[0154] Table 3 Measured bolt hole data

[0155]

[0156] Among them, the position degree of bolt hole 3 satisfies the requirement of being greater than the first set allowable threshold and less than the first set upper limit threshold, and the position degree of the remaining bolt holes is less than the first set upper limit threshold; triggering the collaborative correction process;

[0157] Calculate the machining allowance of the bolt hole as shown in Table 3, and then solve it based on the coordinated adjustment amount: ,satisfy ; Adjust the border: ; Directional coupling coefficient: , the calculated position adjustment vector of bolt hole 1 is (0.08, -0.06), the position adjustment vector of bolt hole 7 is (-0.07, 0.05), and the other bolt holes are not adjusted; , .

[0158] The corrected coordinates of bolt hole 1 are , the corrected coordinates of bolt hole 7 are ; Expanded aperture: , .

[0159] The angle difference of the bolt holes is 22.7°, which is greater than 10° and does not trigger the center offset verification.

[0160] For example, model: high-performance passenger car wheel hub 20×9.0J (load level 6), PCD: 5×120 mm, bolt hole theoretical coordinates (the origin of the detection coordinate system is the hub center):

[0161] The measured bolt hole center coordinates and deviations are shown in Table 4:

[0162] Table 4 Actual bolt hole detection data

[0163]

[0164] Overall deviation judgment: the maximum direction angle is 169.4°, the minimum deviation direction angle is 161.6°; the deviation direction angle difference = 169.4° - 161.6 = 7.8°, which is less than the angle deviation threshold of 10°;

[0165] Deviation from the mean ;

[0166] Vector synthesis ratio: deviation vector sum: ;

[0167] , and the modulus length: , the deviation vector synthesizes the modulus , which is determined to be an overall offset.

[0168] To detect the runout of the mounting surface, you can use a probe to directly measure or use a dial indicator to measure, or use a laser displacement sensor to measure. , allowing center hole correction;

[0169] Center hole position correction: Unit vector calculation: ; The compensation coefficient is 0.8, and the corrected center coordinates are: , and then Re-execute bolt hole collection and position calculation as the benchmark.

[0170] In other embodiments, in the center point selection step, the measurement points are collected using a spiral progressive path:

[0171] Measuring point height coordinates: , where H is the center hole height, j=1, 2, ..., M;

[0172] Angular coordinates: ;when When the axial bending detection is triggered: calculate the center offset of each height layer , Represents the average center of each altitude layer, if If the maximum value is greater than the preset maximum allowable eccentricity value, it is determined that the axis of the center hole is bent.

[0173] When the center hole axis is determined to be curved, calculate the curvature gradient: ,

[0174] like Less than or equal to the gradient threshold, then the turning vector is corrected Otherwise, execute the scrapping steps.

[0175] Specifically, the maximum value allowed for eccentricity is , gradient threshold ;

[0176] For example, wheel hub parameters: Model: Commercial Vehicle 22.5×12.00 (Load Level 10), center hole design radius: ; Center hole height: H = 60;

[0177] The spiral progressive measurement point collection is adopted: the measurement point distribution is as shown in Table 5:

[0178] Table 5 Measurement point distribution collection

[0179]

[0180] Axial bending test: Calculate the average center of the circle: ;

[0181] ; ;

[0182] Then calculate the offset of each layer: ;

[0183] Maximum offset: ; Determine whether the center hole axis is curved, and then perform gradient calculation: , , then compensation is made;

[0184] The compensated turning vector is , , , , the calculation of other layers is omitted, at height At, along the vector Turning is performed in the direction, and the turning depth is the measured center and vector The absolute value of .

[0185] In other embodiments, after determining that the step is scrapped, detection data is obtained, and when it is determined that only a single bolt hole has a position deviation greater than the first set upper limit threshold, collaborative trimming is also adopted: the position of multiple bolt holes is adjusted simultaneously to achieve multi-hole collaborative offset compensation, and the steps adopted are the same as when only a single bolt hole has a position deviation less than or equal to the first set upper limit threshold.

[0186] The present invention also provides a system comprising the following modules:

[0187] Datum establishment module: used to manually select four points on the hub end face to establish the initial three-coordinate system;

[0188] Center calibration module: The input end is connected to the output end of the reference establishment module for electrical signal connection. The probe is controlled to uniformly collect data from multiple points in the central axis hole, calculate the measured center of the circle, and compare it with the theoretical center of the circle.

[0189] Dynamic measuring point allocation module: The input end is connected to the output end of the center calibration module for electrical signal connection, and the number of measuring points of the bolt hole is adjusted according to the offset direction angle of the center hole;

[0190] Position calculation module: The input end is connected to the output end electrical signal of the dynamic measurement point allocation module to calculate the coordinate deviation of each bolt hole and trigger the over-limit judgment based on the set threshold;

[0191] Compensation decision module: The input end is connected to the electrical signal of the output end of the position calculation module. When the bolt hole deviation is greater than the allowable threshold but less than or equal to the upper threshold, a turning correction instruction is generated; when the deviation is greater than the upper threshold, a scrapping instruction is triggered;

[0192] Coordinate system recalibration module: The input end is connected to the output end of the center calibration module. When the measured center of the circle deviates greatly from the theoretical center of the circle, the detection coordinate system is rebuilt with the measured center of the circle as the origin, and the theoretical coordinates of the bolt hole are corrected.

[0193] Roundness detection module: The input end is connected to the output end of the coordinate system recalibration module. After the coordinate system is recalibrated, multiple measurement points are collected at the center hole to calculate the radial distance standard deviation.

[0194] Collaborative finishing module: The input end is connected to the electrical signal of the output end of the position calculation module. When a single bolt hole exceeds the limit, the turning plan is optimized with the global minimum turning amount as the goal;

[0195] Turning control module: The input end is connected to the output end of the supplementary decision module and performs turning operations according to the compensation instructions.

[0196] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A three-coordinate position detection method, characterized in that: The following steps are involved: Manual point selection: Manually select four points on the hub end face as reference points, and establish the initial three-coordinate system with the four reference points; Center point acquisition: Control the probe to evenly collect data from multiple points on the central axis hole as calibration points. Use multiple calibration points to determine the center of the central axis hole, and combine them with the initial coordinate system to establish the detection coordinate system. Bolt hole collection: collect data at 4 points evenly around the circumference of each bolt hole; Position calculation: calculate the coordinates of multiple bolt holes, calculate the position, and calculate the coordinate deviation of each bolt hole based on the theoretical coordinates; Deviation judgment: If the position deviations of all bolt holes are less than or equal to the first set allowable threshold, and the absolute values ​​of the diameter deviations of all bolt holes are less than or equal to the second set allowable threshold, the output is qualified. Otherwise, the over-limit judgment step is executed; Over-limit judgment: If the diameter deviation of any bolt hole is greater than the second set allowable threshold and / or the position deviation of any bolt hole is greater than the first set upper limit threshold, the scrapping step is triggered; otherwise, the compensation step is executed; Compensation: According to the coordinate deviation of the bolt hole, the lathe performs turning correction; Scrap: The wheel hub has irreparable hole defects and will be handed over to staff for subsequent processing.

2. The three-coordinate position detection method according to claim 1, characterized in that: In the center point selection step: The number of collection points is ≥6; When the measured center of the center hole With the theoretical center Offset When , the coordinate system recalibration is triggered: by Reconstruct the detection coordinate system for the origin; According to the formula , the corrected bolt hole theoretical coordinates are , where k is the bolt hole number.

3. The three-coordinate position detection method according to claim 2, characterized in that: The bolt hole acquisition step includes dynamic measurement point allocation: Get the center hole offset angle ; exist The number of measurement points for bolt holes within the interval is increased to 6; The remaining bolt holes maintain 4 measuring points.

4. The three-coordinate position detection method according to claim 2 or 3, characterized in that: When the coordinate system recalibration is triggered, the center hole roundness detection step is added: ≥12 measuring points are evenly collected around the circumference of the center hole; Calculate each measuring point to The radial distance set ; If the radial distance standard deviation , determine that the center hole is unevenly turned and perform center hole compensation: identify the three points with the largest distance deviation and generate a correction vector group; Output center hole turning amount: .

5. The three-coordinate position detection method according to claim 4, characterized in that: The turning path of the center hole compensation is: As the center of the circle, a non-uniform turning trajectory is generated according to the correction vector group; the maximum turning depth is located at the point with the maximum distance deviation, and the depth is distributed according to Δr×(1+cosθ); The turning path of the center hole compensation satisfies the hub assembly constraints: Turning depth control: maximum turning depth satisfy: ; Continuous gradient requirement: The turning depth function is: ;in, Indicates the circumference angle, is the maximum deviation direction angle; Verification: Perform a roundness recheck after turning.

6. The three-coordinate position detection method according to claim 4, characterized in that: The compensation step further includes: when only a single bolt hole position deviation is less than or equal to a first set upper limit threshold, performing collaborative trimming: adjusting the position of multiple bolt holes simultaneously to achieve multi-hole collaborative offset compensation.

7. The three-coordinate position detection method according to claim 6, characterized in that: The compensation step further comprises: If the angle difference of all bolt hole coordinate deviations is less than or equal to the angle deviation threshold, and the deviation mean μ>0.1mm, and the deviation vector synthesis modulus length >0.9, it is judged as overall offset; Then perform center offset verification and measure the radial runout of the hub mounting surface ; like , where the value of a is 0.2mm, then the center hole position is corrected ,in is the deviation direction unit vector, is the compensation coefficient; like , then no center hole correction is performed; Then with Re-execute bolt hole collection and position calculation as the benchmark.

8. The three-coordinate position detection method according to claim 4, characterized in that: In the center point selection step, the measurement points are collected using a spiral progressive path: Measuring point height coordinates: , where H is the center hole height, j=1, 2, ..., M; Angular coordinates: ;when When the axial bending detection is triggered: calculate the center offset of each height layer , Represents the average center of each altitude layer, if If the maximum value is greater than the preset maximum allowable eccentricity value, it is determined that the axis of the center hole is bent.

9. The three-coordinate position detection method according to claim 8, characterized in that: When the center hole axis is determined to be curved, calculate the curvature gradient: , like When the gradient threshold is less than or equal to the value, the turning amount is corrected. Otherwise, execute the scrapping steps.

10. A system for implementing the three-coordinate position detection method according to any one of claims 1 to 9, characterized in that: Includes the following modules: Datum establishment module: used to manually select four points on the hub end face to establish the initial three-coordinate system; Center calibration module: The input end is connected to the output end of the reference establishment module for electrical signal connection. The probe is controlled to uniformly collect data from multiple points in the central axis hole, calculate the measured center of the circle, and compare it with the theoretical center of the circle. Dynamic measuring point allocation module: The input end is connected to the output end of the center calibration module for electrical signal connection, and the number of measuring points of the bolt hole is adjusted according to the offset direction angle of the center hole; Position calculation module: The input end is connected to the output end electrical signal of the dynamic measurement point allocation module to calculate the coordinate deviation of each bolt hole and trigger the over-limit judgment based on the set threshold; Compensation decision module: The input end is connected to the electrical signal of the output end of the position calculation module. When the bolt hole deviation is greater than the allowable threshold but less than or equal to the upper threshold, a turning correction instruction is generated; when the deviation is greater than the upper threshold, a scrapping instruction is triggered; Coordinate system recalibration module: The input end is connected to the output end of the center calibration module. When the measured center of the circle deviates greatly from the theoretical center of the circle, the detection coordinate system is rebuilt with the measured center of the circle as the origin, and the theoretical coordinates of the bolt hole are corrected. Roundness detection module: The input end is connected to the output end of the coordinate system recalibration module. After the coordinate system is recalibrated, multiple measurement points are collected at the center hole to calculate the radial distance standard deviation. Collaborative finishing module: The input end is connected to the electrical signal of the output end of the position calculation module. When a single bolt hole exceeds the limit, the turning plan is optimized with the global minimum turning amount as the goal; Turning control module: The input end is connected to the output end of the supplementary decision module and performs turning operations according to the compensation instructions.

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