Industrial CT measurement calibration method, measurement method, and readable medium for blades

Abstract

The present invention relates to an industrial CT measurement calibration method and a measurement method for blades. The calibration method comprises the following steps: A. selecting at least one blade from a plurality of blades to be measured as a standard part, selecting a typical wall thickness part of the standard part, and obtaining the wall thickness of the typical wall thickness part; B. cutting at least one slice from the standard part, with the cutting direction being the chord direction of the blade; C. manufacturing a gauge block according to the wall thickness of the typical wall thickness part obtained in step A, the width of the gauge block corresponding to the wall thickness, and the height of the gauge block being at least the height of the slice in step B; D. hollowing out the typical wall thickness part corresponding to the slice, filling the gauge block obtained in step C into the hollowed-out position to obtain a filled slice, and then filling the filled slice back into the standard part from its cutting position in step B; and E. performing industrial CT scanning and measurement on the standard part obtained in step D.

Description

Technical Field

[0001] The present invention relates to the field of measurement, and in particular to an industrial CT measurement calibration method, a measurement method, and a readable medium for a blade. Background Art

[0002] Blades are key components of high-performance power systems such as aircraft engines and gas turbines. Due to their complex internal cooling structure and long-term service in complex cyclic thermal stress environments, high requirements are placed on their aerodynamic shape, performance strength and dimensional accuracy. Blade dimensions such as wall thickness, inner cavity size, and profile size are important parameters related to their performance and assembly accuracy and need to be accurately measured.

[0003] Conventional non-destructive blade wall thickness measurement methods mainly include ultrasonic method, eddy current method, and industrial CT method. The eddy current method is affected by factors such as the normal alignment of the eddy current thickness gauge, probe radius compensation, and workpiece size. The measurement accuracy is low, and the eddy current probe needs to be in contact with the measured part, which is difficult to automate and has low efficiency. The ultrasonic detection method, due to the limitations of the detection principle, can only detect single-layer wall structures. At the same time, since the probe and blade need to be coupled, the measurement results are greatly affected by the curvature of the blade and the error is large. These shortcomings limit its scope of use.

[0004] In recent years, with the development of industrial CT detection technology, especially the progress of industrial CT hardware, advanced algorithms and measurement software, CT measurement of engine and gas turbine blade size has become possible. At the same time, because industrial CT technology can clearly and intuitively display the internal structure, composition, defects, etc. of the inspected object in the form of two-dimensional tomographic images or three-dimensional stereo images under non-destructive conditions, compared with ultrasonic testing and eddy current testing that can only measure wall thickness, it can not only obtain the internal structural characteristics of the object but also measure the internal dimensions and surfaces, and has been increasingly used and paid attention to.

[0005] Industrial CT detection technology has obvious advantages over ultrasonic and eddy current methods. However, due to its complex measurement process and many influencing factors, its measurement accuracy and uncertainty evaluation methods are still immature compared to mature measurement methods such as three-coordinate measurement. In particular, it is necessary to use applicable measurement standards to control the measurement process and evaluate the measurement accuracy and uncertainty.

[0006] In the prior art, the standard parts used for measurement by CT detection technology are conventional standard parts of regular geometric size, such as hollow cylinders, stepped parts, multiple balls strung on rod-shaped parts, etc. (cited from Welkenhuyzen, Frank, et al. "Industrial computer tomography for dimensional metrology: Overview of influence factors and improvement strategies." Proceedings of the 4th international conference on optical measurement techniques for structures and systems: Optimess 2009. Shaker Publishing BV, 2009).

[0007] However, the inventors found that the materials used for aircraft engine and gas turbine blades often have large linear attenuation coefficients and complex blade shapes in structure. The wall thickness distribution on different sections is different. The ray penetration thickness varies greatly in different directions during CT scanning. The reconstructed image is prone to beam hardening and scattered line artifacts, which interfere with boundary selection during measurement, resulting in large measurement errors. When using conventional regular geometric body size standard parts for size calibration, the correction effect is often poor because the influence of the material and structure of the parts themselves is not considered. Therefore, it is necessary to design special size standard parts to calibrate the measurement and evaluate the measurement accuracy and uncertainty.

[0008] In view of the shortcomings of the above-mentioned industrial CT technology in the detection of aircraft engine and gas turbine blade size, such as the lack of applicable measurement standards and measurement accuracy and uncertainty evaluation methods, the art needs an industrial CT measurement calibration method and measurement method for blades to achieve CT measurement accuracy calibration and uncertainty evaluation of aircraft engine and gas turbine blade size. Summary of the invention

[0009] The object of the present invention is to provide an industrial CT measurement and calibration method for blades.

[0010] The object of the present invention is to provide an industrial CT measurement method for blades.

[0011] An object of the present invention is to provide a computer readable medium.

[0012] According to one aspect of the present invention, an industrial CT measurement and calibration method for blades includes: step A. selecting at least one blade from a plurality of blades to be measured as a standard part, selecting a typical wall thickness part of the standard part, and obtaining the wall thickness of the typical wall thickness part; step B. cutting at least one slice from the standard part, with the cutting direction being the chord direction of the blade; step C. manufacturing a gauge block according to the wall thickness of the typical wall thickness part obtained in step A, wherein the width of the gauge block corresponds to the wall thickness, and the height of the gauge block is at least the height of the slice in step B; step D. hollowing out the typical wall thickness part corresponding to the slice, filling the gauge block obtained in step C into the hollowed-out position to obtain a filled slice, and then filling the filled slice back into the standard part from its cutting position in step B; step E. performing industrial CT scanning and measurement on the standard part obtained in step D to obtain the uncertainty corresponding to the typical wall thickness part of the standard part corresponding to the test conditions of the CT scan.

[0013] In one or more embodiments of the calibration method, in step D, it also includes hollowing out the angle position of the slice, manufacturing a corresponding angle gauge block, and filling the hollowed-out angle position; in step E, it also includes obtaining the uncertainty corresponding to the angle of the standard part corresponding to the test conditions of the CT scan.

[0014] In one or more embodiments of the calibration method, in the step D, the angle of the angular position is measured to obtain an angle measurement value and an uncertainty.

[0015] In one or more embodiments of the calibration method, in the step D, it also includes punching holes in the slice, including at least two groups of holes, the direction of the first group of holes is the height direction of the slice, and the direction of the second group of holes is perpendicular to the direction of the first group of holes; each group of holes includes holes of at least three sizes, corresponding to the maximum value, minimum value and intermediate value of the aperture of the blade to be measured; in the step E, it also includes obtaining the uncertainty corresponding to the hole of the standard part corresponding to the test conditions of the CT scan.

[0016] In one or more embodiments of the calibration method, in step D, the hole is measured to obtain the measured values ​​of the hole diameter, cylindricity and position, and the corresponding uncertainties.

[0017] In one or more embodiments of the calibration method, in step C, the gauge blocks are measured to obtain width measurement values ​​of each gauge block, parallelism measurement values ​​of two surfaces in the height direction of each gauge block, and corresponding uncertainties.

[0018] In one or more embodiments of the calibration method, in step E, the calculation of uncertainty includes the standard uncertainty introduced by the measurement method, the uncertainty introduced by the pixel size, the standard uncertainty introduced by the standard part calibration uncertainty, the uncertainty introduced by the temperature difference, and the standard uncertainty introduced by the systematic error.

[0019] In one or more embodiments of the calibration method, in step A, the typical wall thickness locations of the standard part are selected to include locations where the structure of the standard part changes, and locations where artifacts of the CT pre-scan image are distributed when the standard part is CT pre-scanned.

[0020] In one or more embodiments of the calibration method, in the step B, a plurality of slices are included, and the distribution direction of the plurality of slices is along the length direction of the standard part.

[0021] According to one aspect of the present invention, an industrial CT measurement method for a blade includes:

[0022] S1. Obtaining the uncertainty obtained by the calibration method described in any one of the above as the measurement uncertainty of the blade;

[0023] S2. Use the CT scanning test conditions of step E of the calibration method as the CT scanning test conditions for industrial CT measurement of the blade to perform a CT scanning test on the blade to obtain a measurement result of the blade, and the measurement uncertainty of the measurement result adopts the measurement uncertainty of S1.

[0024] According to one aspect of the present invention, a computer readable medium has a computer program thereon, and the program is executed by a processor to implement the following steps:

[0025] S10. Obtaining the uncertainty obtained by the calibration method described in any one of the above as the measurement uncertainty of the blade;

[0026] S20. Obtaining the CT scanning test conditions of step E of the calibration method as the CT scanning test conditions for industrial CT measurement of the blade, and performing a CT scanning test on the blade to measure the value of the blade;

[0027] S30. Use the measurement uncertainty obtained in S10 as the uncertainty of the measurement value obtained in S20, and output the measurement result.

[0028] In summary, the improved effects of the present invention include but are not limited to:

[0029] By selecting blades from the batch of blades to be tested as standard parts, and using slicing, hollowing out and then filling the standard parts as the structure of the standard parts, the CT measurements of different sizes of different parts of the blades are calibrated, so that the uncertainty results of the industrial CT measurement of the blades are accurate, avoiding the problem of large CT measurement errors of different types of parts in different parts when conventional regular geometric size standard parts are used for size calibration in the prior art, and the measurement accuracy can reach ±0.05mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments. It should be noted that the drawings are only examples and are not drawn to scale, and should not be used as a limitation on the actual scope of protection required by the present invention, wherein:

[0031] Figure 1 It is a flowchart of a calibration method for industrial CT measurement of a blade according to an embodiment.

[0032] Figure 2 It is a schematic flow chart of an industrial CT measurement method for a blade according to an embodiment.

[0033] Figure 3 is a schematic structural diagram of a standard component and a slice position according to a calibration method of an embodiment.

[0034] Figure 4 4 is a schematic diagram of a cross-sectional structure of a slice of a standard component according to a calibration method of an embodiment.

[0035] Figure 5 is a schematic structural diagram of a gauge block of a calibration method according to an embodiment.

[0036] Figure 6 It is a schematic diagram of execution steps of a program of a computer-readable medium according to an embodiment. DETAILED DESCRIPTION

[0037] The following discloses a variety of different implementation methods or embodiments of the subject technical solution. To simplify the disclosure, specific examples of each element and arrangement are described below. Of course, these are merely examples and are not intended to limit the scope of protection of the present invention. "One embodiment", "one embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic associated with at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of the present application may be appropriately combined.

[0038] Flowcharts are used in this application to illustrate the operations performed by the system according to the embodiments of the application. It should be understood that the preceding or following operations are not necessarily performed precisely in order. Other operations may also be added to these processes, or one or more operations may be removed from these processes.

[0039] The blades in the following embodiments are made of nickel-based high-temperature alloy single crystal turbine blades as an example, but the present invention is not limited thereto.

[0040] refer to Figure 1 , Figure 2 As shown, in one embodiment, in the industrial CT measurement method of the blade, it is necessary to calibrate through a calibration piece to obtain accurate measurement uncertainty. Figure 1 , calibration methods include:

[0041] Step A. selecting at least one blade from a plurality of blades to be measured as a standard part, selecting a typical wall thickness portion of the standard part, and obtaining the wall thickness of the typical wall thickness portion;

[0042] Specifically, refer to Figure 3 , based on the blade 10 as a standard part, the blade 10 is pre-scanned by CT, and according to the structure and blade shape characteristics of the blade 10, combined with the distribution of artifacts such as beam hardening and scattering of the CT image of the actual X-ray detection parts, the typical wall thickness parts are selected. The typical wall thickness parts generally include the leading edge 101, the trailing edge 102 and other parts of the blade 10 where the structure changes suddenly, and the parts with poor image quality found by the CT pre-scan, that is, the parts where the artifacts are distributed. The typical wall thickness parts are numbered as (T1, T2, T3, ..., TN), and the approximate size of the corresponding parts is measured on the real object or model diagram to obtain the wall thickness (t1, t2, t3, ..., tN) at the corresponding position.

[0043] Step B. cutting at least one slice from the standard part, with the cutting direction being the chord direction of the blade;

[0044] Specifically, refer to Figure 3 The number of slices cut from the blade 10 is at least one, Figure 3 For example, the three slices 1, 2, and 3 are included, but not limited thereto. The cutting direction of the slices is the chord direction, that is, the direction from the leading edge 101 to the trailing edge 102 of the blade 10. The distribution direction of the slices 1, 2, and 3 is the length direction of the blade 10.

[0045] Step C. According to the wall thickness of the typical wall thickness portion obtained in step A, a gauge block is manufactured, the width of the gauge block corresponds to the wall thickness, and the height of the gauge block is at least the height of the slice in step B;

[0046] Specifically, please refer to Figure 5As shown, the width W of the gauge block 20 corresponds to the wall thickness of the typical wall thickness part, that is, (t1, t2, t3, ..., tN), and the height is H. Among them, H is selected according to the corresponding CT detection parameters, but is not less than the thickness of the slice, generally not less than 1mm. The material of the gauge block 20 is the same as that of the part to be tested to avoid the influence of the linear attenuation coefficient of different materials on the CT detection results.

[0047] Measure the gauge block 20, for example, using a vernier caliper, to obtain the standard gauge block width value W and the measurement uncertainty ±δ W , and the parallelism PL of the upper and lower surfaces of each gauge block and its uncertainty ±δ PL .

[0048] Step D. hollowing out the typical wall thickness portion corresponding to the slice, filling the gauge block obtained in step C into the hollowed-out position to obtain a filled slice, and then filling the filled slice back into the standard part from the cutting position in step B;

[0049] For details, please refer to Figure 4 As shown, the hollowed-out part may include typical wall thickness parts numbered (T1, T2, T3, ..., T18), but it is not limited thereto, and the hollowed-out position corresponding to the typical wall thickness part may be determined according to the measurement requirements. After hollowing out, the gauge block 20 of step C is filled into the hollowed-out position. The specific filling method may be to use bonding to obtain a hollowed-out and filled slice structure. Taking slice 1 as an example, after hollowing out and filling, it is a filled slice. After obtaining the filled slice, the corresponding slice 1 is filled with the filled slice at the cutting position of the blade 10. Similarly, slices 2 and 3 are also filled back into the corresponding cutting positions of the blade 10 after hollowing out and filling.

[0050] In one embodiment, twelve typical wall thickness locations (T1, T2, T3, ..., T18) of slice 1 are selected for hollowing out and filling with gauge blocks 20. The design values ​​of the typical wall thickness locations and the measurement values ​​of the gauge blocks 20 are shown in Table 1 below.

[0051] Table 1 Design values ​​of turbine blade section wall thickness

[0052]

[0053] Continue to refer Figure 4 As shown, in some embodiments, in addition to the typical wall thickness portion, a hole and angle structure can also be set in the slice 1 to provide calibration for the hole and angle measurement results of the actual blade CT measurement results. Figure 4As shown, in one embodiment, a hollowed-out area at an angle position is set in slice 1, including the angle θ1 between T4-T17 and the angle θ2 between T5-T18. And similar to the operation of a typical wall thickness part, the angle gauge blocks corresponding to the angles θ1 and θ2 are designed, and the design values ​​of the angles θ1 and θ2 are set according to the actual angle structure to be measured. For example, the design values ​​of the angles θ1 and θ2 shown in the figure are 45° and 28° respectively, and the hollowed-out part is filled. Before filling, the angle gauge blocks are measured, and common devices can be used, such as an angle ruler, to obtain the measurement values ​​of the angles θ1 and θ2, as well as the uncertainty.

[0054] Continue to refer Figure 4 In one embodiment, the measurement structure of the hole punched in the slice 1 can also be used to calibrate the CT measurement results of the actual leaf. Figure 4 As shown, the holes punched in slice 1 include two hole structures, one hole direction is perpendicular to the cross section, that is, the thickness direction of slice 1, such as the first group of holes 11, and the other hole direction is parallel to the upper and lower surfaces of slice 1, that is, perpendicular to the direction of the first group of holes 11, such as the second group of holes 12. Each group of holes includes at least three sizes of holes, corresponding to the maximum, minimum and intermediate values ​​of the aperture of the blade to be measured, such as Φmin = 0.3mm, Φmid = 0.5mm and Φmax = 0.8mm shown in the figure. Similarly, the holes are measured to obtain the measured values ​​of the hole diameter Φ, cylindricity C, and position P, as well as the measurement uncertainty ±δ of the corresponding measurement results. Φ , ±δ C , ±δ P When measuring the position, the center point of a gauge block on the slice can be selected as the reference point. Unlike the typical wall thickness and angle structure, there is no need to set a gauge block to fill the punched area after drilling. The reason is that the purpose of drilling is to calibrate the measurement of the film cooling holes and internal channels of the actual blade, so there is no need to fill the punched area.

[0055] Step E: Perform industrial CT scanning and measurement on the standard part obtained in step D to obtain the uncertainty corresponding to the typical wall thickness position of the standard part corresponding to the test conditions of the CT scanning.

[0056] Specifically, the following steps may be included:

[0057] E1. Perform a CT scanning test on the standard part of the blade 10 after the slices have been filled back into it, obtain the best scanning parameters through the test, and obtain the best CT two-dimensional and three-dimensional images of the standard part.

[0058] E2. Perform CT image analysis and measurement on the design dimensions of each slice corresponding to the CT two-dimensional and three-dimensional images obtained in E1 to obtain the CT measurement values ​​of the design dimensions. For example, obtain the CT measurement value of the wall thickness. And repeat the CT image analysis and measurement, the number of times can be more than 10 times. The CT measurement values ​​include the CT measurement values ​​of the gauge blocks except for the typical wall thickness parts, the parallelism of the gauge blocks, the angle, the aperture, the cylindricity of the holes, and the position of the holes. In order to make the measurement more objective, when repeated measurements are made, it is advisable to use different inspectors, at different times, in the same inspection environment and under the same inspection parameters. Each measurement dimension should be measured at least 3 times for each measurement, and the average value is taken as the CT value of this measurement.

[0059] For uncertainty analysis, in some embodiments, a mathematical model can be established:

[0060] The error formed in the data acquisition and image reconstruction process is regarded as the system error b, which represents the measurement uncertainty formed in the two processes of data acquisition and image reconstruction. The measurement mathematical model of the industrial CT measurement result Y can be expressed as:

[0061] Y=yb; (1).

[0062] The measured dimension y is affected by the measurement method, pixel size, calibration accuracy of the calibration piece, and environmental factors. Therefore:

[0063] y=f(y i ,y v ,y cal ,y Δt ) (2)

[0064] In the formula, y i Indicates the measured value; y v represents the pixel (voxel) size; α represents the thermal expansion coefficient; Δt represents the temperature difference.

[0065] The sensitivity coefficient of each influencing factor can be expressed as: αΔt

[0066]

[0067] According to the propagation law formula,

[0068]

[0069] The measurement result is expressed as: Y = (yb) ± U, where the inclusion factor of U is k and the inclusion probability is P.

[0070] The uncertainty of measurement includes the standard uncertainty introduced by the measurement method, the uncertainty introduced by the pixel size, the standard uncertainty introduced by the calibration uncertainty of the standard parts, the uncertainty introduced by the temperature difference, and the standard uncertainty introduced by the system error. Specifically, it can be:

[0071] Measurement uncertainty calculation: Based on the classification and evaluation methods of general metrological technical specifications such as ISO 15530-3:2011 and ISO / IEC Guide 98-2008, combined with the above mathematical model, uncertainty calculation is performed.

[0072] 1) Standard uncertainty u(y) introduced by the measurement method i )

[0073] The standard uncertainty component introduced by repeated measurements is calculated by the Class A uncertainty assessment method. The measured dimension (such as wall thickness) is measured n times (n ≥ 10), and the i-th measurement result is expressed as y i , the average value of n measurements is The standard deviation of the measurement result represents the uncertainty component introduced by repeated measurements, that is:

[0074]

[0075] Its sensitivity coefficient is:

[0076] 2) Uncertainty introduced by pixel (voxel) size u(y v )

[0077] If the pixel size of the CT system detector is a and the magnification during detection is M, the pixel (voxel) size of the industrial CT reconstructed image can be calculated to be a / M. Therefore, assuming that the effect of the pixel (voxel) size on the measurement result satisfies a rectangular distribution with an error limit of ±a / M, its standard uncertainty is:

[0078]

[0079] Its sensitivity coefficient is:

[0080] 3) Standard uncertainty u introduced from the calibration uncertainty of the calibration component cal

[0081] When measuring the size of a certain dimension element on the calibration piece, the calibration uncertainty given is recorded as u cal .

[0082] Its sensitivity coefficient is:

[0083] 4) Uncertainty u(y) introduced by temperature difference Δt)

[0084] Assuming the temperature distribution is uniform, the standard uncertainty of the temperature difference is

[0085]

[0086] Its sensitivity coefficient is:

[0087] 5) Standard uncertainty u(b) introduced by system error

[0088] For a calibration block, a certain calibration dimension x cal Perform multiple measurements and record the result of each measurement as y i ′,n(n≥10) times of measurement results to calculate the average value The system error is:

[0089]

[0090] According to the evaluation method and formula of Class A uncertainty, the Class A standard uncertainty component introduced by the systematic error is calculated and obtained as follows:

[0091]

[0092] Its sensitivity coefficient is:

[0093] Calculate the combined uncertainty.

[0094]

[0095] Calculate the extended certainty.

[0096] Taking the confidence probability P = 95% and the confidence factor k = 2, the expanded uncertainty can be calculated by the following formula:

[0097]

[0098] The final result of industrial CT measurement of the measured dimension at a certain position of the blade is expressed as:

[0099]

[0100] The following is an example of CT measurement of the wall thickness of a typical wall thickness area T1 of slice 1:

[0101] 1) Standard uncertainty u(y) introduced by the measurement method i )

[0102] The standard uncertainty component introduced by repeated measurements is calculated by the Class A uncertainty assessment method. The wall thickness dimension to be measured is measured n times (n ≥ 10), and the result of the i-th measurement is expressed as yi , the average value of n measurements is

[0103] Its standard uncertainty is:

[0104]

[0105] Its sensitivity coefficient is:

[0106] 2) Uncertainty introduced by pixel (voxel) size u(y v )

[0107] According to formula (6), the uncertainty u(y v )for:

[0108]

[0109] Its sensitivity coefficient is:

[0110] 3) Standard uncertainty u introduced from the calibration uncertainty of the calibration component cal

[0111] When measuring the size of a certain dimension element on the calibration piece, the calibration uncertainty given is recorded as u cal =0.002.

[0112] Its sensitivity coefficient is:

[0113] 4) Uncertainty u(y) introduced by temperature difference Δt )

[0114] The linear expansion coefficient of the sample material is α = 13.3 × 10 -6 ℃ -1 , the temperature difference is 2℃, k is According to formula (7), the standard uncertainty of the calculated temperature difference is:

[0115]

[0116] Its sensitivity coefficient is:

[0117] 5) Standard uncertainty u(b) introduced by system error

[0118] Typical wall thickness T1 calibration dimension x cal Perform multiple measurements (measurement results are shown in Table 2), and each measurement result is recorded as y i ′,n(n≥10) times of measurement results to calculate the average value The system error is:

[0119]

[0120] According to formula (9), the type A standard uncertainty component introduced by the system error is calculated as follows:

[0121]

[0122] Its sensitivity coefficient is:

[0123] Calculate the combined uncertainty.

[0124] According to formula (9), the combined uncertainty is:

[0125]

[0126] Calculate the extended certainty.

[0127] Assuming the confidence probability P = 95% and the confidence factor k = 2, the expanded uncertainty can be calculated by formula (11):

[0128]

[0129] The industrial CT measurement results of the typical wall thickness area T1 of slice 1 are:

[0130]

[0131] The CT measurement values ​​and measurement results are shown in Table 2:

[0132] Table 2: CT measurement results of T1 at typical wall thickness locations in slice 1

[0133]

[0134]

[0135] CT measurements were performed on other typical wall thickness locations of slice 1, as well as typical wall thickness locations of slices 2 and 3. The CT measurement results are shown in the following table:

[0136] Table 3: CT measurement results of T1 at typical wall thickness locations of slices 1, 2, and 3

[0137]

[0138] Similar to the above steps, the CT measurement results of the aperture and angle of the holes in some embodiments are obtained. The position, cylindricity, parallelism and other measurement values ​​of the remaining holes are also calculated by the mathematical model of uncertainty above, and are not listed here one by one due to space limitations.

[0139] Table 4 CT measurement results of hole size

[0140]

[0141] Table 5 CT measurement results of angles

[0142]

[0143] The obtained uncertainty can be applied to the CT measurement values ​​of the blades in the same batch as the uncertainty of the blade measurement.

[0144] That is, for the industrial CT measurement of the blade, it is only necessary to measure the calibration result of the standard part, that is, the uncertainty result, and then the industrial CT measurement of other blades under the CT scanning parameters can be applied. That is, there is no need to measure each blade and perform the calibration method steps, and it is only necessary to obtain the uncertainty of the CT measurement obtained by the calibration method.

[0145] As mentioned above, Figure 2 As shown, the industrial CT measurement method of the blade may include:

[0146] S1. Obtaining the uncertainty obtained by the calibration method described in the above embodiment as the measurement uncertainty of the blade;

[0147] S2. Use the CT scanning test conditions of step E of the calibration method as the CT scanning test conditions for industrial CT measurement of the blade to perform a CT scanning test on the blade, and obtain the CT measurement result of the blade. The measurement uncertainty of the measurement result adopts the measurement uncertainty of S1.

[0148] According to another aspect of the present invention, in some embodiments, the present invention further provides a computer-readable medium, such as a storage medium, on which a computer program is stored, in combination with Figure 6 As shown, the program is executed by the processor to implement the following steps:

[0149] S10. Obtain the uncertainty obtained by the calibration method described in the above embodiment as the CT measurement uncertainty of the blade;

[0150] S20. Obtaining the CT scanning test conditions of step E of the calibration method as the CT scanning test conditions for industrial CT measurement of the blade, and performing a CT scanning test on the blade to measure the value of the blade;

[0151] S30. Use the measurement uncertainty obtained in S10 as the uncertainty of the measurement value obtained in S20, and output the CT measurement result.

[0152] Those skilled in the art can understand that the program can also be used to execute additional steps, such as the steps in the above calibration method and measurement method that can be executed by the program.

[0153] In some embodiments, the storage medium may be integrated into the processor. The processor and the storage medium may reside in an application specific integrated circuit (ASIC). The ASIC may reside in a user terminal. In one or more embodiments, the processor and the storage medium may reside in a user terminal as discrete components.

[0154] Computer readable medium includes both computer storage medium and communication medium, and it includes any medium that facilitates computer program to transfer from one place to another place. Storage medium can be any available medium that can be accessed by computer. As an example and not limitation, such computer readable medium can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage device, or can be used to carry or store the desired program code of instruction or data structure form and any other medium that can be accessed by computer. Any connection is also properly referred to as computer readable medium. For example, if software is transmitted from website, server or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL or wireless technology such as infrared, radio and microwave are just included in the definition of medium. Disk and disc as used herein include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, wherein disk often reproduces data magnetically, while disc reproduces data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0155] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

[0156] In summary, the beneficial effects of the calibration method and CT measurement method provided in the above embodiments include but are not limited to, by selecting blades from the batch of blades to be tested as standard parts, and slicing, hollowing out and then filling the standard parts as the structure of the standard parts, calibrating the CT measurement of different sizes of different parts of the blades, so that the uncertainty results of the industrial CT measurement of the blades are accurate, avoiding the problem of large CT measurement errors of different parts and types of parts caused by the use of conventional regular geometric size standard parts for size calibration in the prior art, and the measurement accuracy can reach ±0.05mm.

[0157] Although the present invention is disclosed as above with the above embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. An industrial CT measurement and calibration method for blades, characterized in that: include: Step A. selecting at least one blade from a plurality of blades to be measured as a standard part, selecting a typical wall thickness portion of the standard part, and obtaining the wall thickness of the typical wall thickness portion; Step B. cutting at least one slice from the standard part, with the cutting direction being the chord direction of the blade; Step C. According to the wall thickness of the typical wall thickness portion obtained in step A, a gauge block is manufactured, the width of the gauge block corresponds to the wall thickness, and the height of the gauge block is at least the height of the slice in step B; Step D. hollowing out the typical wall thickness portion corresponding to the slice, filling the gauge block obtained in step C into the hollowed-out position to obtain a filled slice, and then filling the filled slice back into the standard part from the cutting position in step B; Step E: Perform industrial CT scanning and measurement on the standard part obtained in step D to obtain the uncertainty corresponding to the typical wall thickness position of the standard part corresponding to the test conditions of the CT scanning.

2. The calibration method according to claim 1, characterized in that: In the step D, it also includes hollowing out the angle position of the slice, manufacturing a corresponding angle gauge block, and filling the hollowed-out angle position; in the step E, it also includes obtaining the uncertainty corresponding to the angle of the standard part corresponding to the test conditions of the CT scan.

3. The calibration method according to claim 2, characterized in that: In step D, the angle of the angular position is measured to obtain an angle measurement value and an uncertainty.

4. The calibration method according to claim 1, characterized in that: In the step D, it also includes punching holes in the slice, including at least two groups of holes, the direction of the first group of holes is the height direction of the slice, and the direction of the second group of holes is perpendicular to the direction of the first group of holes; each group of holes includes holes of at least three sizes, corresponding to the maximum value, minimum value and intermediate value of the aperture of the blade to be measured; in the step E, it also includes obtaining the uncertainty corresponding to the hole of the standard part corresponding to the test conditions of the CT scan.

5. The calibration method according to claim 4, characterized in that: In the step D, the hole is measured to obtain the measured values ​​of the hole diameter, cylindricity and position, as well as the corresponding uncertainties.

6. The calibration method according to claim 1, characterized in that: In the step C, the gauge blocks are measured to obtain the width measurement value of each gauge block, the parallelism measurement value of two surfaces in the height direction of each gauge block, and the corresponding uncertainty.

7. The calibration method according to claim 1, characterized in that: In step E, the calculation of uncertainty includes the standard uncertainty introduced by the measurement method, the uncertainty introduced by the pixel size, the standard uncertainty introduced by the standard part calibration uncertainty, the uncertainty introduced by the temperature difference, and the standard uncertainty introduced by the system error.

8. The calibration method according to claim 1, characterized in that: In the step A, the typical wall thickness parts of the standard part are selected including the structural mutation parts of the standard part, and the parts where the artifacts of the CT pre-scan image are distributed when the standard part is CT pre-scanned.

9. The calibration method according to claim 1, characterized in that: In the step B, a plurality of slices are included, and the distribution direction of the plurality of slices is along the length direction of the standard part.

10. An industrial CT measurement method for blades, characterized in that: include: S1. Obtaining the uncertainty obtained by the calibration method according to any one of claims 1 to 9 as the measurement uncertainty of the blade; S2. Use the CT scanning test conditions of step E of the calibration method as the CT scanning test conditions for industrial CT measurement of the blade to perform a CT scanning test on the blade to obtain a measurement result of the blade, and the measurement uncertainty of the measurement result adopts the measurement uncertainty of S1.

11. A computer readable medium having a computer program thereon, characterized in that The program is executed by the processor to implement the following steps: S10. Obtaining the uncertainty obtained by the calibration method according to any one of claims 1 to 9 as the measurement uncertainty of the blade; S20. Obtaining the CT scanning test conditions of step E of the calibration method as the CT scanning test conditions for industrial CT measurement of the blade, and performing a CT scanning test on the blade to measure the value of the blade; S30. Use the measurement uncertainty obtained in S10 as the uncertainty of the measurement value obtained in S20, and output the measurement result.

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