Method for determining uncertainty of rotation measurement system based on optical image measurement method

Abstract

The invention discloses a method for determining the uncertainty of a rotation measurement system based on an optical image measurement method, and the method comprises the steps: determining a measurement repeatability error and a size measurement resolution error of the rotation measurement system, and introducing a quantization error uncertainty component # imgabs0 # to the rotation measurement system according to the measurement repeatability error and the size measurement resolution error; determining an uncertainty component # imgabs1 # introduced by the temperature error to the rotation measurement system; determining an uncertainty component # imgabs2 # introduced by the part surface measurement error to the rotation measurement system; determining a depth measurement error of a workpiece measurement characteristic, and determining an uncertainty component # imgabs4 # introduced by the measurement error of the surface measurement depth characteristic of the part to a rotation measurement system in combination with an axial run-out error # imgabs3 # of a rotating shaft; and obtaining the uncertainty of the rotation measurement system according to the mathematical model in combination with each uncertainty component. According to the method, the uncertainty of the specific equipment can be accurately evaluated.

Description

Technical Field

[0001] The present invention relates to the field of metrology and detection, and in particular to a method for determining the uncertainty of a rotation measurement system based on an optical image measurement method. Background Art

[0002] The measurement accuracy of measuring instruments is usually described by measurement precision. When describing the measurement accuracy of measuring instruments with simple structures, measurement precision has the technical characteristics of easy operation. However, when describing some complex test systems, a single parameter description is difficult to make a clear statement about the measurement accuracy of the entire system. This results in inaccurate description of the measurement accuracy of complex systems. Especially in some new types of combined mechanical actions or multiple measurement methods, the existing concept of measurement accuracy is difficult to accurately describe the degree of conformity between the measurement results and the true value.

[0003] For example, the rotation measurement system based on the optical image measurement method includes an optical image measurement device and a mechanical rotation device. The mechanical rotation device clamps and rotates the workpiece, and the optical image measurement device measures the workpiece. When measuring the circumferential characteristic position and geometric dimensions of parts in the shape of shafts and cylinders, it is necessary to rotate the parts axially and calculate the measurement results by synthesizing the optical results with the rotation angle of the shaft, the diameter of the measuring surface and other parameters. The accurate evaluation of the measurement results is difficult. It is not conducive to the analysis of the test results and the determination of the accuracy of the test results. In addition, since there are many optional measuring devices for the above-mentioned measurement tasks, the parameters such as the rotation runout of the part axis of different measuring devices, the detection accuracy of the optical measuring equipment, and the control accuracy of the rotation angle of the rotating machine are not the same. There is a lack of unified means to compare and determine the ability and level of different systems to complete the measurement task. Therefore, it is necessary to design a method to determine the uncertainty of the measurement system to evaluate the accuracy of the measurement system itself. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a method for determining the uncertainty of a rotation measurement system based on an optical image measurement method, which can accurately reflect the accuracy of the measurement results of the evaluated measurement system.

[0005] The present invention is achieved through the following technical solutions: A method for determining the uncertainty of a rotation measurement system based on an optical image measurement method comprises the following steps: When the mechanical rotating device is in a static state, error parameters of the optical measuring device are obtained; Determine the axial runout error of the rotating shaft of a mechanical rotating device using a standard circular measuring tool ; Use the target to determine the horizontal displacement error of the rotating axis ; Using Polyhedron to Determine the Angle Control Error of Rotation Axis ; Determine the measurement repeatability error and dimensional measurement resolution error of the rotation measurement system, and quantify the error uncertainty component introduced by the measurement repeatability error and dimensional measurement resolution error to the rotation measurement system. ; After the rotating measurement system and the workpiece are subjected to constant temperature treatment, the expected limit value of the temperature difference between the rotating measurement system and the workpiece is determined based on the temperature difference between the rotating measurement system and the workpiece. The uncertainty component introduced by the temperature error to the rotating measurement system is determined based on the expected limit value of the temperature difference between the rotating measurement system and the workpiece, the maximum size of the part, and the difference in the linear expansion coefficient between the rotating measurement system and the workpiece. ; According to the workpiece feature size, error parameters of the optical measuring device, horizontal displacement error of the rotating axis and rotation axis angle control error , determine the uncertainty component introduced by the part surface measurement error to the rotation measurement system ; Determine the depth measurement error of the workpiece measurement feature combined with the axial runout error of the rotating axis , determine the uncertainty component introduced by the measurement error of the depth characteristic of the part surface to the rotation measurement system ; Establish the uncertainty data model of the rotation measurement system, based on the mathematical model and combined with the uncertainty components , uncertainty components , uncertainty components and uncertainty components , and obtain the uncertainty of the rotation measurement system.

[0006] Preferably, the determination of the error parameter of the optical measuring device includes: The measurement method in "JJF1318-2011 Image Measuring Instrument Calibration Specification" is used to obtain the error parameters of the optical measuring device, including the detection error. , XY plane measurement error , vertical dimension measurement error , consistency error of measurement results of each section , Image side head detection error , Image probe size measurement error and zoom detection error .

[0007] Preferably, the axial runout error of the rotating shaft is The determination includes: The standard circular measuring tool is made coaxial with the rotation axis of the mechanical rotating device, a plurality of measuring sections are set on the standard circular measuring tool, a plurality of measuring points are set at circumferential intervals on each measuring section, the standard circular measuring tool is rotated, and a first measurement value of each measuring point is obtained by an optical measuring device; Rotate the standard circular measuring tool in the opposite direction and repeat the above process to obtain a second measurement value at each measuring point; The runout error of each measuring section is determined according to the measurement value corresponding to each measuring section, and the axial runout error of the rotating shaft is determined according to the runout errors of all measuring sections.

[0008] Preferably, the horizontal displacement error of the rotation axis is The determination includes: The target and the mechanical rotating device are coaxial with each other so that each edge of the square target in the target forms an angle of 45° with the axis of the rotating shaft; Determine the first minimum circumscribed circle radius of the square target according to the intersection of the edge lines of the square target, and repeat multiple times to obtain a first minimum circumscribed circle radius group; Rotate the square target forward and backward respectively, and repeat the above process to obtain the second minimum circumscribed circle radius group and the third minimum circumscribed circle radius group; The horizontal displacement error of the rotating axis is determined based on the three groups of minimum circumscribed circle radius groups and combined with the detection error of the optical measuring device.

[0009] Preferably, the multifaceted prism is used to determine the rotation axis angle control error ,include: The polyhedron is mounted on the rotating shaft of the mechanical rotating device, and the laser light is reflected to the optical measuring device through the reflecting surface of the polyhedron, and a point light spot is formed in the optical measuring device, and the polyhedron is rotated to obtain a first measurement value of the point light spot position corresponding to each prism face in the direction perpendicular to the rotating shaft; Then the polyhedron is rotated in the opposite direction, and the above process is repeated to obtain a second measurement value of the position of the point-shaped light spot corresponding to each facet along the direction perpendicular to the rotation axis; The angle control errors corresponding to different angles of the polyhedron are calculated according to the first measurement value and the second measurement value, and the maximum angle control error is taken as the rotation axis angle control error.

[0010] Preferably, the quantization error uncertainty component The determination includes: Determine the uncertainty component introduced by the dimensional measurement resolution error based on the minimum dimensional measurement resolution of the rotation measurement system ; Fix the glass line ruler on the center line of the rotating shaft of the rotating measuring device, and when the glass line ruler is leveled, repeatedly measure the set measuring points and calculate the average value, and determine the error between the average value and the standard value of the measuring point; Rotate the glass scale 180° and repeat the above process. Determine the standard deviation of the error according to the Bessel method and use it as the uncertainty component introduced by the measurement repeatability. ; Comparison of uncertainty components introduced by resolution error in dimensional measurement and the uncertainty component introduced by measurement repeatability , the value with large uncertainty component is taken as the uncertainty component of quantization error .

[0011] Preferably, the method for calculating the expected value of the temperature difference limit between the rotation measurement system and the measured workpiece is as follows:

[0012] The uncertainty component introduced by the temperature error to the rotation measurement system is The calculation method is as follows:

[0013] Where: is the uncertain component of temperature error factor; The expected limit value of the temperature difference between the rotating measuring system and the workpiece after constant temperature, .The larger of the length and diameter of the measured object during actual measurement; .The difference between the linear expansion coefficient of the equipment reference scale and the material of the measured object during the actual measurement process.

[0014] Preferably, the uncertainty component introduced by the part surface measurement error to the rotation measurement system is The method of determining is as follows:

[0015] in, is the uncertainty component of the part surface measurement error, is the maximum radius of the feature of the part to be measured, is the nominal radius of the polyhedron, is the maximum length of the feature distribution of the part to be measured, . is the standard round rod sampling length, is the measurement error in the XY plane; is the distribution angle of the feature to be measured on the part surface, is the image probe size measurement error, is the image head tilt detection error, It is the magnification detection error.

[0016] Preferably, the uncertainty component introduced by the characteristic measurement error of the part surface measurement depth into the rotation measurement system is The method of determining is as follows:

[0017] in, is the vertical dimension measurement error; is the consistency error of the measurement results of each section; is the axial runout error.

[0018] Preferably, the mathematical model is as follows:

[0019] Where: is the spatial position measurement uncertainty; is the uncertain component of temperature error factor; Uncertainty components introduced for resolution and repeatability; is the uncertainty component of the part surface measurement error; is the uncertainty component of depth measurement error; k is the expanded uncertainty calculation factor.

[0020] Compared with the prior art, the present invention has the following beneficial technical effects: The present application provides a method for determining the uncertainty of a rotation measurement system based on an optical image measurement method, which performs multi-dimensional measurement on the rotation measurement system, determines the uncertainty components of each dimension, and then establishes a digital-analog model to couple the uncertainty components to obtain the uncertainty of the rotation measurement system; this method can calculate the measurement uncertainty of a device with a mechanical rotation device when detecting the circumferential characteristic position of a part. The uncertainty has a reproducible experimental process and calculation flow, and the uncertainty can be rechecked at any time. The expressed uncertainty has a corresponding confidence probability, which facilitates the introduction of the result into other data calculation processes; through the scientific and detailed description of the overall accuracy of the measurement system through uncertainty, the confidence probability of each measurement result given by the measurement system can be significantly improved, thereby improving the data value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0022] Figure 1It is a schematic diagram of the structure of the measurement system of the present invention; Figure 2 is a distribution diagram of the measurement points of the present invention; Figure 3 This is a schematic diagram of the target position angle of the present invention; Figure 4 It is a schematic diagram of measuring the rotation axis angle control error of the present invention.

[0023] In the figure: a, chuck; b, optical measurement module; c, marked round rod; d, bed; e, rotating shaft; f, inductive micrometer; g, Z-axis projection of the central axis of the rotating shaft; h, field of view of the imaging system; i, square target; (j, k), target edge; (m, n, o, p.), target vertex; q, photoelectric autocollimator; r, laser line; s, 24-sided prism. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0026] See also Figure 1 A rotation measurement system based on optical image measurement method includes a mechanical rotating device and an optical measuring device arranged thereon.

[0027] The mechanical rotating device comprises a bed d, on which a driving box is arranged, the driving box is connected to a rotating shaft e, the rotating shaft e is connected to a chuck a, the chuck is used to clamp a workpiece or a standard measuring tool, and the card can adopt a three-jaw chuck.

[0028] The optical measuring device comprises an optical measuring module b and an electrical sensing micrometer f.

[0029] During the measurement process, the measurement accuracy of the rotation measurement system is affected by the coupling between the optical measurement device and the mechanical rotation device. Therefore, it is necessary to determine the uncertainty of the measurement system and evaluate the measurement accuracy of the measurement system. The specific process is as follows.

[0030] A method for determining the uncertainty of a rotation measurement system based on an optical image measurement method comprises the following steps: Step 1: When the mechanical rotating device is in a static state, the error parameters of the optical measuring device are obtained; Step 2: Use a standard circular measuring tool to determine the axial runout error of the rotating shaft of the mechanical rotating device ; Use the target to determine the horizontal displacement error of the rotating axis ; Step 3: Use a polyhedron to determine the rotation axis angle control error ; Step 4: Determine the measurement repeatability error and dimensional measurement resolution error of the rotation measurement system, and quantify the error uncertainty component introduced by the measurement repeatability error and dimensional measurement resolution error to the rotation measurement system. ; Step 5: After the rotating measurement system and the workpiece are subjected to constant temperature treatment, the expected limit value of the temperature difference between the machine body and the workpiece to be measured is determined based on the temperature difference between the rotating measurement system and the workpiece. The uncertainty component introduced by the temperature error to the rotating measurement system is determined based on the expected limit value of the temperature difference between the machine body and the workpiece to be measured, the maximum size of the part, and the difference in the linear expansion coefficient between the machine body and the workpiece to be measured. ; Step 6: Determine the uncertainty component introduced by the part surface measurement error to the rotation measurement system based on the workpiece feature size, the error parameters of the optical measurement device and the rotation axis angle control error. ; Step 7: Determine the depth measurement error of the workpiece measurement feature and combine it with the axial runout error of the rotating axis to determine the uncertainty component introduced by the depth feature measurement error of the part surface to the rotating measurement system. ; Step 8: Establish the uncertainty data model of the rotation measurement system, based on the mathematical model and combined with the uncertainty components , uncertainty components , uncertainty components and uncertainty components , and obtain the uncertainty of the rotation measurement system.

[0031] The uncertainty determination method of the rotation measurement system performs multi-dimensional measurement on the rotation measurement system to determine the uncertainty components of each dimension, then establishes a digital-analog model to couple the uncertainty components to obtain the uncertainty of the rotation measurement system, and evaluates the performance of the rotation measurement system when completing the measurement task based on the final uncertainty to improve the accuracy of the measurement.

[0032] Example 1 A method for determining the uncertainty of a rotation measurement system based on an optical image measurement method comprises the following steps: Step 1: Perform compliance check on the rotation measurement system; S1.1. Confirm that the rotation measurement system uses an optical or laser measurement solution as the core measurement method. The measurement results related to the measurement results are directly or indirectly derived from the measurement results collected by the optical or laser measurement system.

[0033] It should be noted that if the rotation measurement system has measurement functions such as a contact measurement probe, this method is not applicable to the determination of its uncertainty, and other evaluation methods must be used to determine its uncertainty.

[0034] S1.2. Determine that the part clamping platform of the rotation measurement system includes at least one axial rotation structure.

[0035] S1.3. Confirm that the mechanical rotating device of the rotation measurement system has angle feedback functions such as code disk, circular grating or dividing disk, and the rotation of the rotating structure can be manual or CNC.

[0036] S1.4. Determine the axial position and number of the rotating structure of the rotation measurement system. When multiple rotating axes are involved, the uncertainty calculation can be performed independently for each rotating axis according to the actual usage scenario.

[0037] Step 2: When the mechanical rotating device is in a static state, an error parameter of the optical measuring device is obtained, and an uncertainty component A of the optical measuring device is determined according to the error parameter; When the mechanical rotating device is stationary, the measurement method in "JJF1318-2011 Image Measuring Instrument Calibration Specification" is used to obtain the detection error of the optical measuring device through corresponding operations. , XY plane measurement error , vertical dimension measurement error , consistency error of measurement results of each section , Image side head detection error , Image probe size measurement error and zoom detection error .

[0038] The uncertainty component A of the optical measuring device in the static state of the mechanical rotating device is determined based on the above error parameters.

[0039] Step 3: Use a standard circular measuring tool to determine the axial runout error of the rotating shaft of the mechanical rotating device; use a target to determine the horizontal displacement error of the rotating shaft; The axial runout error of the rotating shaft is determined as follows: In this embodiment, the standard circular measuring tool is a standard round rod c, a standard round rod (diameter ≥ 20 mm, length ≥ 200 mm, straightness better than 2 μm, axial runout better than 1 μm).

[0040] S3.1. Fix the standard round rod to the rotating shaft through a chuck so that the axial direction of the round rod is coaxial with the rotating shaft and the axis of the round rod coincides with the axis of the rotating shaft.

[0041] It should be noted that in the clamping process of the standard round bar, only the built-in clamp of the rotation measurement system can be used, and other auxiliary clamps cannot be used to avoid the influence of the auxiliary clamp on the measurement accuracy.

[0042] S3.2 Fix the inductive micrometer on the optical measurement module, and the accuracy of the inductive micrometer is better than 0.5μm; When the inductive micrometer f is difficult to fix in the above position, it is fixed to the guide rail or other stable part of the mechanical rotating device.

[0043] S3.3 Adjust the standard round rod according to the data of the inductive micrometer so that the axis of the round rod is consistent with the axis of the rotating shaft, and the axis of the round rod and the axis of the rotating shaft coincide as much as possible.

[0044] S3.4 Select an effective length of not less than 150mm on the standard round bar .

[0045] 3.4.1 Select 5 measurement sections on the effective length .

[0046] 3.4.2 Set multiple measuring points at intervals along the circumference on each measuring section.

[0047] In this embodiment, a measuring point is set every 30° rotation, and each measuring section has a total of 12 measuring points. During the measurement process, the rotation direction of the rotating axis is ensured to remain unchanged, and each measuring point is measured in turn.

[0048] 3.4.3 The measurement method is: the probe of the inductive micrometer is pointed and perpendicular to the axis of the round bar, and the measurement value of each measuring point is obtained by the inductive micrometer. , the measurement point uniform distribution method is shown in Figure 2 .

[0049] 3.4.4 Repeat 3.4.3 to obtain all measurement data of the 5 measurement sections ; 3.4.5 Repeat steps 3.4.2 to 3.4.4 and rotate the rotation axis in the opposite direction to obtain the measurement data of all measurement points of the 5 measurement sections. .

[0050] After completing 3.5.4, continue to rotate the standard round bar for more than 360° in the sampling rotation direction of 3.4.2. Start to rotate back to the 0° position in the opposite direction of the sampling rotation direction of 3.4.2 and repeat the measurement steps from 3.4.2 to 3.4.4. During this measurement, the rotation direction of the standard round bar is opposite to the previous rotation direction. Do not change the rotation direction during the measurement. Obtain all measurement data of the 5 axial measurement positions .

[0051] 3.4.6. Determine the axial runout error of each measuring section based on the measurement data of each measuring point on the measuring section , calculate the axial runout error using formula 1 ,

[0052] in, for Axial runout error of position.

[0053] 3.4.7. Determine the axial runout error of the rotating axis based on the axial runout error of each measuring section and calculate the axial runout error using Formula 2.

[0054] ; in, . is the maximum value of the axial runout error of the rotating shaft; The method of using a target to determine the horizontal displacement error of the rotating axis is as follows: The minimum original radius of the target is determined by the optical measuring device, and the process is repeated for multiple times. The horizontal displacement error of the rotating axis is determined based on the multiple minimum radii obtained and the detection error of the optical measuring device.

[0055] S3.5 Fix the special target on the rotating shaft. A square target is formed in the target. Adjust the target position so that the edges of the square target in the target form a 45° angle with the axis of the rotating shaft, and the projection of the center of the square target along the Z axis is as close to the central axis of the rotating shaft as possible. The field of view of the optical measurement module can be zoomed without moving the X and Y axes so that the entire square target is within the field of view. See the schematic diagram of the target position and angle. Figure 3 . Record the side length of the square target , when the target is a rectangle with an aspect ratio less than 2, the length of the long side is recorded as .Require ≥5mm.

[0056] 3.5.1 Use the optical measuring device to measure the four edges of the target, such as straight lines j and k, and calculate the positions of points m, n, o, and p according to the intersection of the four straight lines. Repeat the measurement 5 times and use the minimum circle covering method to calculate the minimum covering circle radius of the five measuring points at the positions of m, n, o, and p, which is recorded as .

[0057] 3.5.2 Repeat the operation in 3.5.1 by rotating the target 360° clockwise along the square of the front view chuck. The measured result is recorded as .

[0058] 3.5.3 Repeat the operation in 3.6.1 by rotating the target 360° counterclockwise along the square of the front view chuck. The measured result is recorded as .

[0059] 3.5.4 Based on the minimum coverage circle radius , , , and combined with the detection error to determine the horizontal displacement error of the rotating axis , calculated according to Formula 4

[0060]

[0061] in, For detection error.

[0062] Step 4: Use a polyhedron to determine the rotation axis angle control error ; S4.1. Install the 24-hedron prism on the rotating shaft and perform the alignment operation on the photoelectric autocollimator. Then move the rotating shaft to make the laser light reflect through the 45° angle of the 24-hedron prism and enter the optical measuring device. Adjust the position until a point-like light spot can be observed in the optical measuring device. The position of the 24-hedron prism after adjustment is as follows: Figure 4 The nominal radius of the 24-hedron is .

[0063] S4.2. The value of the point light spot position in the field of view of the optical measuring device along the vertical direction of the rotation axis is recorded as , rotate the 24-hedron 15°, and measure the position of the light spot in the field of view along the vertical direction of the rotation axis again , continue to rotate the 24-hedron by 15° each time, and measure . Back Position, reverse rotation of 24-hedron 15° each time, measured .

[0064] S4.3. Determine the angle control error corresponding to different angles based on the measured value .

[0065]

[0066] Where: .Angle control error of the i-th measurement point; , .24-hedron at 0 degree rotation position and The reading of the light spot along the vertical direction of the rotation axis during the rotation position (in μm); .24-hedron certified deviation value at this angle (unit"); .The distance between the center of the 24-hedron and the imaging system (in μm).

[0067] S4.3 takes the maximum angle control error as the rotation axis angle control error (unit"); Step 5: Determine the measurement repeatability error and dimensional measurement resolution error of the rotation measurement system, and quantify the error uncertainty component introduced by the measurement repeatability error and dimensional measurement resolution error to the rotation measurement system. .

[0068] S5.1 Determine the dimensional measurement resolution of the rotation measurement system. The error introduced by the dimensional measurement resolution obeys a uniform distribution. Determine the minimum dimensional measurement resolution It is the effective resolution, that is, the effective resolution of the length sensor used in the rotation measurement system. It is not possible to use software subdivision resolution higher than the sensor's own resolution. The uncertainty component introduced by the dimensional measurement resolution error is determined based on the minimum dimensional measurement resolution. ,

[0069] in, .Uncertainty introduced by resolution; The minimum resolution for measuring the size of the device under test, in μm.

[0070] S5.2 To determine the uncertainty component introduced by measurement repeatability, the method is to fix the glass linear ruler at the center line of the rotating shaft. After alignment and leveling, select 10 test points evenly distributed over a length of ≥15cm. Take the average value of each point reading 3 times, and calculate the indication error of the point by comparing it with the standard value of the scale of the linear ruler. Rotate the linear ruler 180° along the axis and repeat the above measurement process, rotate it 180° in the opposite direction, and repeat the above process. A total of 30 indication error results are obtained. The standard deviation is calculated using the Bessel formula, and the result is the uncertainty component introduced by measurement repeatability. .

[0071] S5.3 Take , The larger value of the two is used as the uncertainty component of the quantization error of the rotation measurement system .

[0072] Step 6: After the rotating measurement system and the workpiece are subjected to constant temperature treatment, the expected limit value of the temperature difference between the machine body and the workpiece to be measured is determined based on the temperature difference between the rotating measurement system and the workpiece. The uncertainty component introduced by the temperature error to the rotating measurement system is determined based on the expected limit value of the temperature difference between the machine body and the workpiece to be measured, the maximum size of the part, and the difference in the linear expansion coefficient between the machine body and the workpiece to be measured. .

[0073] The uncertainty component introduced by the temperature error due to factors such as ambient temperature fluctuations, differences in the linear expansion coefficient of the measured material and the length reference scale of the rotating measurement system .

[0074] After the rotating measuring system is fully kept at a constant temperature, the temperature difference between the reference scale and the measured part It falls within the range of (-0.3~0.3)℃, obeys uniform distribution, and determines the uncertainty component caused by temperature change according to the temperature difference ; When the on-site ambient temperature fluctuates greatly or the constant temperature is not sufficient, it is necessary to re-evaluate according to the actual situation value:

[0075]

[0076] Where: is the uncertain component of temperature error factor; The expected limit value of the temperature difference between the machine body and the workpiece after constant temperature, .The larger of the length and diameter of the measured object during actual measurement; .The difference between the linear expansion coefficient of the equipment reference scale and the material of the measured object during the actual measurement process.

[0077] Step 7: Determine the uncertainty component introduced by the part surface measurement error to the rotation measurement system based on the workpiece feature size, the error parameters of the optical measurement device and the rotation axis angle control error. ; The rotating body to be measured in the actual measurement process is referred to as a part, and the dimensional error of the part surface measurement ; Determine the measurement size error based on the part's topographic features, and the distribution angle of the features of the part's surface to be measured , the maximum length of the distribution , maximum feature radius .

[0078]

[0079] in, is the uncertainty component of the part surface measurement error; is the maximum radius value of the feature of the part to be measured; is the nominal radius of the 24-hedron prism, ; The maximum length of the feature distribution of the part to be measured; . is the standard round rod sampling length; is the measurement error in the XY plane; is the distribution angle of the feature to be measured on the part surface; is the image probe size measurement error; is the image side head detection error; is the magnification detection error, The component is only introduced when variable magnification detection is involved in the actual measurement of parts, and is taken as 0 if it is not involved.

[0080] Step 8: Determine the depth measurement error of the workpiece measurement feature and combine it with the axial runout error of the rotating axis to determine the uncertainty component introduced by the depth feature measurement error of the part surface to the rotating measurement system. ; Depth feature measurement error of part surface ;

[0081] in is the uncertainty component of depth measurement error; is the vertical dimension measurement error; is the consistency error of the measurement results of each section; is the axial runout error.

[0082] Step 9: Establish the uncertainty data model of the rotation measurement system, based on the mathematical model and combined with the uncertainty components , uncertainty components , uncertainty components and uncertainty components , and obtain the uncertainty of the rotation measurement system.

[0083] The mathematical model of uncertainty is as follows: ( k =2) Where: is the spatial position measurement uncertainty; is the uncertain component of temperature error factor; Uncertainty components introduced for resolution and repeatability; is the uncertainty component of the part surface measurement error; is the uncertainty component of depth measurement error; k is the expanded uncertainty calculation factor.

[0084] Step 10: Verification of uncertainty S10.1 The final spatial position measurement uncertainty value determined by the above steps includes the measurement uncertainty components introduced by various factors in the measurement process, and the result data should satisfy Formula 11.

[0085] Formula 11. U. Uncertainty of measurement result; MPEV. Absolute value of maximum permissible error of equipment; Step 11: Application of uncertainty The results of the present invention can be applied to equipment with mechanical rotating devices to quantify the accuracy of measurement results when detecting the circumferential characteristic position of parts. This method can also be used to evaluate the performance of different measurement systems when completing measurement tasks, providing data support for the selection of measurement equipment and the decision-making of measurement plans.

[0086] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for determining the uncertainty of a rotation measurement system based on optical image measurement, characterized in that: The following steps are involved: When the mechanical rotating device is in a static state, error parameters of the optical measuring device are obtained; Determine the axial runout error of the rotating shaft of a mechanical rotating device using a standard circular measuring tool ; Use the target to determine the horizontal displacement error of the rotating axis ; Using Polyhedron to Determine the Angle Control Error of Rotation Axis ; Determine the measurement repeatability error and dimensional measurement resolution error of the rotation measurement system, and quantify the error uncertainty component introduced by the measurement repeatability error and dimensional measurement resolution error to the rotation measurement system. ; After the rotating measurement system and the workpiece are subjected to constant temperature treatment, the expected limit value of the temperature difference between the rotating measurement system and the workpiece is determined based on the temperature difference between the rotating measurement system and the workpiece. The uncertainty component introduced by the temperature error to the rotating measurement system is determined based on the expected limit value of the temperature difference between the rotating measurement system and the workpiece, the maximum size of the part, and the difference in the linear expansion coefficient between the rotating measurement system and the workpiece. ; According to the workpiece feature size, error parameters of the optical measuring device, horizontal displacement error of the rotating axis and rotation axis angle control error , determine the uncertainty component introduced by the part surface measurement error to the rotation measurement system ; Determine the depth measurement error of the workpiece measurement feature combined with the axial runout error of the rotating axis , determine the uncertainty component introduced by the measurement error of the depth characteristic of the part surface to the rotation measurement system ; Establish the uncertainty data model of the rotation measurement system, based on the mathematical model and combined with the uncertainty components , uncertainty components , uncertainty components and uncertainty components , and obtain the uncertainty of the rotation measurement system.

2. The method for determining the uncertainty of a rotation measurement system based on optical image measurement according to claim 1, characterized in that: Determining the error parameters of the optical measuring device includes: The measurement method in "JJF1318-2011 Image Measuring Instrument Calibration Specification" is used to obtain the error parameters of the optical measuring device, including the detection error. , XY plane measurement error , vertical dimension measurement error , consistency error of measurement results of each section , Image side head detection error , Image probe size measurement error and zoom detection error .

3. The method for determining the uncertainty of a rotation measurement system based on optical image measurement according to claim 1, characterized in that: The axial runout error of the rotating axis The determination includes: The standard circular measuring tool is made coaxial with the rotation axis of the mechanical rotating device, a plurality of measuring sections are set on the standard circular measuring tool, a plurality of measuring points are set at circumferential intervals on each measuring section, the standard circular measuring tool is rotated, and a first measurement value of each measuring point is obtained by an optical measuring device; Rotate the standard circular measuring tool in the opposite direction and repeat the above process to obtain a second measurement value at each measuring point; The runout error of each measuring section is determined according to the measurement value corresponding to each measuring section, and the axial runout error of the rotating shaft is determined according to the runout errors of all measuring sections.

4. The method for determining the uncertainty of a rotation measurement system based on optical image measurement according to claim 1, characterized in that: The horizontal displacement error of the rotation axis The determination includes: The target and the mechanical rotating device are coaxial with each other so that each edge of the square target in the target forms an angle of 45° with the axis of the rotating shaft; Determine the first minimum circumscribed circle radius of the square target according to the intersection of the edge lines of the square target, and repeat multiple times to obtain a first minimum circumscribed circle radius group; Rotate the square target forward and backward respectively, and repeat the above process to obtain the second minimum circumscribed circle radius group and the third minimum circumscribed circle radius group; The horizontal displacement error of the rotating axis is determined based on the three groups of minimum circumscribed circle radius groups and combined with the detection error of the optical measuring device.

5. The method for determining the uncertainty of a rotation measurement system based on optical image measurement according to claim 1, characterized in that: The method of using a polyhedron to determine the rotation axis angle control error ,include: The polyhedron is mounted on the rotating shaft of the mechanical rotating device, and the laser light is reflected to the optical measuring device through the reflecting surface of the polyhedron, and a point light spot is formed in the optical measuring device, and the polyhedron is rotated to obtain a first measurement value of the point light spot position corresponding to each prism face in the direction perpendicular to the rotating shaft; Then the polyhedron is rotated in the opposite direction, and the above process is repeated to obtain a second measurement value of the position of the point-shaped light spot corresponding to each facet along the direction perpendicular to the rotation axis; The angle control errors corresponding to different angles of the polyhedron are calculated according to the first measurement value and the second measurement value, and the maximum angle control error is taken as the rotation axis angle control error.

6. The method for determining the uncertainty of a rotation measurement system based on optical image measurement according to claim 1, characterized in that: The quantization error uncertainty component The determination includes: Determine the uncertainty component introduced by the dimensional measurement resolution error based on the minimum dimensional measurement resolution of the rotation measurement system ; Fix the glass line ruler on the center line of the rotating shaft of the rotating measuring device, and when the glass line ruler is leveled, repeatedly measure the set measuring points and calculate the average value, and determine the error between the average value and the standard value of the measuring point; Rotate the glass scale 180° and repeat the above process. Determine the standard deviation of the error according to the Bessel method and use it as the uncertainty component introduced by the measurement repeatability. ; Comparison of uncertainty components introduced by resolution error in dimensional measurement and the uncertainty components introduced by measurement repeatability , the value with large uncertainty component is taken as the uncertainty component of quantization error .

7. The method for determining the uncertainty of a rotation measurement system based on optical image measurement according to claim 1, characterized in that: The calculation method of the expected value of the temperature difference limit between the rotating measurement system and the measured workpiece is as follows: The uncertainty component introduced by the temperature error to the rotation measurement system is The calculation method is as follows: Where: is the uncertain component of temperature error factor; The expected limit value of the temperature difference between the rotating measuring system and the workpiece after constant temperature, .The larger of the length and diameter of the measured object during actual measurement; .The difference between the linear expansion coefficient of the equipment reference scale and the material of the measured object during the actual measurement process.

8. The method for determining the uncertainty of a rotation measurement system based on optical image measurement according to claim 1, characterized in that: The uncertainty component introduced by the surface measurement error of the part to the rotation measurement system The method of determining is as follows: in, is the uncertainty component of the part surface measurement error, is the maximum radius of the feature of the part to be measured, is the nominal radius of the polyhedron, is the maximum length of the feature distribution of the part to be measured, . is the standard round rod sampling length, is the measurement error in the XY plane; is the distribution angle of the feature to be measured on the part surface, is the image probe size measurement error, is the image head tilt detection error, It is the magnification detection error.

9. The method for determining the uncertainty of a rotation measurement system based on optical image measurement according to claim 1, characterized in that: The uncertainty component introduced by the characteristic measurement error of the part surface measurement depth to the rotation measurement system The method of determining is as follows: in, is the vertical dimension measurement error; is the consistency error of the measurement results of each section; is the axial runout error.

10. The method for determining the uncertainty of a rotation measurement system based on optical image measurement according to claim 1, characterized in that: The mathematical model is as follows: Where: is the spatial position measurement uncertainty; is the uncertain component of temperature error factor; Uncertainty components introduced for resolution and repeatability; is the uncertainty component of the part surface measurement error; is the uncertainty component of depth measurement error; k is the expanded uncertainty calculation factor.

Images