阅读说明：本技术 一种涡轮工作叶片最终检验自动检测测量方法 (Automatic detection and measurement method for final inspection of turbine working blade ) 是由 田灿 孙维彬 查继林 李扬 杨劲松 韩丹 于 2020-06-20 设计创作，主要内容包括：本发明公开了一种涡轮工作叶片最终检验自动检测测量方法,所述测量方法基于三坐标测量机和计算机实现,所述计算机用于控制三坐标测量机和处理测量数据,测量方法包括有确定测量尺寸、坐标系建立、坐标数据读取、测量稳定性评价、测量系统分析、测量程序编制、测量不确定度分析与评价和测量数据一致性验证。采用本发明所述的测量方法,可有效地降低操作者的劳动强度,减少了测具的设计与制造费用,降低了加工测量的成本,提高了测量精度,减少了测量误差,提高了测量效率,满足批量生产的需求；具有自动测量、测量精度高、测量成本低、无需辅助设备及二次操作等优点,实现测量精度高和测量效率高的双重优势。(The invention discloses an automatic detection and measurement method for final inspection of a turbine working blade, which is realized based on a three-coordinate measuring machine and a computer, wherein the computer is used for controlling the three-coordinate measuring machine and processing measurement data, and the measurement method comprises the steps of determining measurement size, establishing a coordinate system, reading coordinate data, evaluating measurement stability, analyzing a measurement system, compiling a measurement program, analyzing and evaluating measurement uncertainty and verifying consistency of the measurement data. By adopting the measuring method, the labor intensity of an operator can be effectively reduced, the design and manufacturing cost of a measuring tool is reduced, the processing and measuring cost is reduced, the measuring precision is improved, the measuring error is reduced, the measuring efficiency is improved, and the requirement of batch production is met; the method has the advantages of automatic measurement, high measurement precision, low measurement cost, no need of auxiliary equipment and secondary operation and the like, and has the dual advantages of high measurement precision and high measurement efficiency.)

1. A turbine working blade final inspection automatic detection measuring method is characterized in that: the measuring method is realized based on a three-coordinate measuring machine and a computer, the computer is used for controlling the three-coordinate measuring machine and processing measured data, the measuring method comprises the steps of determining a measuring size, establishing a coordinate system, reading coordinate data, evaluating measuring stability, analyzing a measuring system, compiling a measuring program, analyzing and evaluating the uncertainty of measurement and verifying the consistency of the measured data, and the measuring method specifically comprises the following steps:

(1) determining the measurement size: identifying the final inspection and measurement size of the turbine working blade in the pre-programmed process rules through a three-coordinate measuring machine;

(2) establishing a coordinate system: establishing a coordinate system on a special measuring chuck in a three-coordinate measuring machine, and converting the coordinate system into a blade coordinate system through corresponding conversion;

(3) reading coordinate data: reading the reference measurement coordinate data, the size measurement point coordinate data and the size tolerance data in a circulating way through high-level programming software of a computer;

(4) and (3) measurement programming: measuring and evaluating the size of a measuring point by using a computer advanced programming assignment statement, and outputting measuring result data;

(5) analyzing a measuring system: selecting 10 parts processed by 3 operators for the programmed measuring program, and analyzing and comparing the parts by a measuring system;

(6) evaluation of measurement stability: carrying out statistical process stability evaluation on the unstable measurement size according to the measurement system meeting the use requirement and the final inspection measurement size condition;

(7) measurement uncertainty analysis and evaluation: selecting the dimension with the strictest tolerance requirement control for measurement uncertainty analysis and evaluation, including evaluation of A-type and B-type measurement uncertainty;

(8) and (3) verifying the consistency of the measured data: and selecting a small batch of parts to verify the consistency of the automatic detection measurement data and the data of the traditional measurement method.

2. The method as claimed in claim 1, wherein the method comprises the following steps: in the process of determining and measuring the dimension, the three-coordinate measuring machine is used for identifying the final inspection and measurement dimension of the turbine working blade in the pre-programmed process rules, except the tooth form and the transfer radius in the turbine working blade, all dimensions of a blade edge plate, a tenon, a blade crown and a blade body need to be identified, wherein the dimension of the tooth form part needs to be used for clamping and positioning and does not need to be detected; the transfer radius size cannot be detected in real time by the measurement software in the three-coordinate measuring machine.

3. The method as claimed in claim 1, wherein the method comprises the following steps: in the process of establishing the coordinate system in the step (2), when a reference coordinate system is established, the reference A surface and the upper end surface of the positioning block are required to be aligned, so that the direction limitation of the Y axis and the Z axis of the blade is realized, namely the degrees of freedom in three directions of XYZ axis can be limited, corresponding values are offset to the YZ center according to the measured values of the reference A surface and the upper end surface of the positioning block, the positions of the Y axis and the Z axis can be limited, corresponding reference points are constructed through the reference of the tenon direction of the blade, the X axis of the reference points is offset to the center of the X axis according to corresponding calculated values, and six degrees of freedom are all limited, namely the establishment of the coordinate system of the blade is finished; when the batch detection is carried out, the blades need to be arranged in a special measuring chuck, and the front position and the rear position do not exceed 2mm, so that the program in the three-coordinate measuring machine can realize automatic error compensation and measurement.

4. The method as claimed in claim 1, wherein the method comprises the following steps: in the coordinate data reading process of the step (3), the dimension measuring point coordinate, the reference measuring point coordinate, the dimension theoretical value and the tolerance data measured by the blade are respectively stored in corresponding data files HIT.TXT, JZHIT.TXT and NOMTOL.TXT, DMIS measuring software is adopted in a computer to carry out assignment programming, the path where the corresponding data file is located is assigned to the corresponding variable, then a command for opening the file to read is carried out, and the data file is circularly read line by using a WHILE/END WHILE flow control command until all data are read.

5. The method as claimed in claim 1, wherein the method comprises the following steps: in the measuring program compiling process of the step (4), measuring points and evaluating sizes and outputting measuring result data by adopting a computer advanced programming assignment statement; in the whole measuring process of the blade, only one time of circularly reading the file and the high-level statement of the assignment variable is needed to be executed when the program is started, and the corresponding data coordinate is input into the corresponding measuring element, so that the batch detection operation can be realized; in addition, program statements are clear, stable and reliable, and only data file modification can be performed when modification is needed, so that program misoperation is prevented.

6. The method as claimed in claim 1, wherein the method comprises the following steps: in the analysis process of the measuring system, 3 operators are selected for the programmed measuring program to respectively measure 10 parts for 3 times, and meanwhile, according to the characteristics of the structure of the blade, the typical sizes of a tenon part, a blade body part and a blade crown part are selected for analyzing the measuring system, and Minitab software is utilized and the operation is carried out according to the following steps: the statistical/quality tool/gauge research/gauge R & R research, the analysis method selects variance analysis, sets the process tolerance of the corresponding size, selects part number, operator, measurement data, and clicks to determine the corresponding analysis result.

7. The method as claimed in claim 1, wherein the method comprises the following steps: in the measurement stability evaluation process of the step (6), for the measurement system which meets the use requirement, the statistical process stability evaluation is carried out on the measurement unstable size according to the final inspection and measurement size condition; verifying the influence degree of the measurement system and the environment related factors on the data: selecting a part, measuring 2 data every day, respectively performing in the morning and afternoon, wherein the temperature and humidity requirement during the measurement period meets the regulation, the stability condition is described by using the measurement data of 10 days, and performing mean value-range control chart analysis, wherein all points of the sample mean value and the sample range are required to be within the control limit, and the control chart is stable without large fluctuation.

8. The method as claimed in claim 1, wherein the method comprises the following steps: in the measurement uncertainty analysis and evaluation process of (7), the dimension with the worst tolerance control is selected for measurement uncertainty analysis and evaluation, including evaluation of A-type and B-type measurement uncertainty: calculating the uncertainty of the measurement according to the measurement data, wherein the result data can be calculated by a probability statistical method, the A-type evaluation of standard uncertainty can be carried out, when the times are enough, the distribution of the measured values should meet normal distribution, but in the actual test measurement process, the times are limited so that the measured values cannot completely meet the normal distribution, but follow t distribution, and in order to achieve the same confidence probability, the measurement deviation range should be expanded and multiplied by the corresponding t distribution t factor; wherein the class A rating for standard uncertainty is:

average value:

the standard deviation of the mean value adopts Bessel formula:

following t distribution, confidence probability 95%, 9 times, looking up table to obtain t_0.95＝2.26

Class a uncertainty:

class B rating of standard uncertainty:

the type B evaluation is calculated by taking the indicating value error of the measuring machine, the measuring machine has a temperature compensation function, and the influence of temperature on the uncertainty is small and can be ignored;

Representation of the synthetic standard uncertainty:

when verifying that the uncertainty of the type B and the tolerance ratio meet the relevant requirements, the uncertainty of the measurement of the measuring instrument is specified to meet 1/4, 1/6 and 1/10 grades of the tolerance of the measured part;

and verifying that the ratio of the product tolerance to the measurement uncertainty of the synthesis standard meets relevant requirements, wherein the ratio of the product tolerance to the measurement uncertainty is required to be more than 4: 1.

9. The method as claimed in claim 1, wherein the method comprises the following steps: in the process of verifying the consistency of the measured data, selecting a small batch of parts, measuring the final inspection size by using an automatic detection method, verifying the consistency of the automatically detected measured data and the data of the traditional measuring method, and analyzing the distribution condition of the deviation values of the two measuring methods.

Technical Field

The invention belongs to the technical field of aeroengine measurement, and particularly relates to a final inspection automatic detection measurement method for a turbine working blade.

Background

The development of aerospace technology has higher and higher requirements on the performance of engines, turbine working blades of the aero-engines are important components of turbine parts and important key parts of the whole engines, and precision machining equipment and processes of the turbine working blades are leading-edge subjects of the national manufacturing field. Because the number of parts is large, the requirement on the precision of the machining size is high, the machining angles are large and complex, the final inspection process mainly depends on a plurality of sets of special measuring tools, sample plates and general measuring tools to carry out manual inspection, and the device has the characteristics of high requirement on the skill level of inspectors, high labor intensity and large number of people. The measuring technology of the working blade is an important step of operations such as reverse engineering, quality detection, blade design, maintenance guidance and the like, blade measurement is an important means for analyzing blade machining allowance and detecting finished product quality, but due to the inherent contradiction between measuring efficiency and measuring precision, efficient and accurate blade measurement is one of the difficulties in the blade machining process.

Along with the increase of the structure and the profile complexity of the turbine working blade, the difficulty of realizing the high-efficiency and rapid measurement of the blade on the premise of ensuring the shape precision of the working blade is increased. Therefore, how to detect accurately and efficiently is an important means for ensuring the manufacturing quality and delivery quality of the blade, but the blade detection has a series of problems, and how to realize rapid measurement based on the measurement advantages of a three-coordinate measuring machine, the method not only has high measurement precision and high measurement efficiency, but also can reduce the labor intensity of operators, reduce the design and manufacturing cost of measuring tools, reduce the processing and measurement cost, improve the measurement precision, reduce the measurement error, and improve the measurement efficiency, and the measurement method is a hotspot of research. In view of the above, the present invention provides a method for automatically detecting and measuring final inspection of turbine working blades.

Disclosure of Invention

The invention aims to provide a more direct and convenient rapid measuring method aiming at the defects of the prior art, so as to solve the problems of difficult improvement of measuring precision and low measuring efficiency and reliability in the final inspection process of the traditional turbine working blade, thereby meeting the requirement of batch production, in particular to an automatic detection and measurement method for the final inspection of the turbine working blade.

In order to solve the technical problems, the invention adopts the technical scheme that: a turbine working blade final inspection automatic detection measuring method is realized based on a three-coordinate measuring machine and a computer, the computer is used for controlling the three-coordinate measuring machine and processing measured data, the measuring method comprises the steps of determining measurement size, establishing a coordinate system, reading coordinate data, evaluating measurement stability, analyzing a measuring system, programming a measuring program, analyzing and evaluating measurement uncertainty and verifying consistency of the measured data, and the method specifically comprises the following steps:

(1) determining the measurement size: identifying the final inspection and measurement size of the turbine working blade in the pre-programmed process rules through a three-coordinate measuring machine;

(2) establishing a coordinate system: establishing a coordinate system on a special measuring chuck in a three-coordinate measuring machine, and converting the coordinate system into a blade coordinate system through corresponding conversion;

(3) reading coordinate data: reading the reference measurement coordinate data, the size measurement point coordinate data and the size tolerance data in a circulating way through high-level programming software of a computer;

(4) and (3) measurement programming: measuring and evaluating the size of a measuring point by using a computer advanced programming assignment statement, and outputting measuring result data;

(5) analyzing a measuring system: selecting 10 parts processed by 3 operators for the programmed measuring program, and analyzing and comparing the parts by a measuring system;

(6) evaluation of measurement stability: carrying out statistical process stability evaluation on the unstable measurement size according to the measurement system meeting the use requirement and the final inspection measurement size condition;

(7) measurement uncertainty analysis and evaluation: selecting the dimension with the strictest tolerance requirement control for measurement uncertainty analysis and evaluation, including evaluation of A-type and B-type measurement uncertainty;

(8) and (3) verifying the consistency of the measured data: and selecting a small batch of parts to verify the consistency of the automatic detection measurement data and the data of the traditional measurement method.

Further, in the final inspection automatic detection measuring method of the turbine working blade, in the process of (1) determining the measurement size, the three-coordinate measuring machine is used for identifying the final inspection measurement size of the turbine working blade in a pre-programmed process rule, except for the tooth form and the transfer radius in the turbine working blade, all sizes of a blade flange plate, a tenon, a blade crown and a blade body need to be identified, wherein the size of the tooth form part needs to be used for clamping and positioning and does not need to be detected; the transfer radius size cannot be detected in real time by the measurement software in the three-coordinate measuring machine.

Furthermore, in the process of establishing the coordinate system in the step (2), when the reference coordinate system is established, the alignment of the reference A surface and the upper end surface of the positioning block is needed, so that the direction limitation of the Y axis and the Z axis of the blade is realized, that is, the degrees of freedom in three directions of an XYZ axis can be limited, the corresponding values are offset to the YZ center according to the measured values of the reference A surface and the upper end surface of the positioning block, that is, the positions of the Y axis and the Z axis can be limited, the corresponding reference points are constructed through the reference of the tenon direction of the blade, the corresponding calculated value of the X axis of the reference point is offset to the X axis center, and the six degrees of freedom are all limited, namely, the establishment of the coordinate system of the blade is finished; when the batch detection is carried out, the blades need to be arranged in a special measuring chuck, and the front position and the rear position do not exceed 2mm, so that the program in the three-coordinate measuring machine can realize automatic error compensation and measurement.

Further, in the automatic detection and measurement method for final inspection of the turbine working blade, in the coordinate data reading process of the step (3), the dimension measurement point coordinate, the reference measurement point coordinate, the dimension theoretical value and the tolerance data measured by the blade are respectively stored in corresponding data files of HIT.TXT, JZHIT.TXT and NOMTOL.TXT, a DMIS measurement software is adopted in a computer for assignment programming, the path where the corresponding data file is located is assigned to the corresponding variable, then a command for opening the file for reading is carried out, and a WHILE/END WHILE flow control command is used for circularly reading the data files line by line until all data reading is finished.

Further, in the method for automatically detecting and measuring the final inspection of the turbine working blade, a computer advanced programming assignment statement is adopted to measure the measuring points and evaluate the dimension and output the measuring result data in the measuring program programming process (4); in the whole measuring process of the blade, only one time of circularly reading the file and the high-level statement of the assignment variable is needed to be executed when the program is started, and the corresponding data coordinate is input into the corresponding measuring element, so that the batch detection operation can be realized; in addition, program statements are clear, stable and reliable, and only data file modification can be performed when modification is needed, so that program misoperation is prevented.

Further, in the final inspection automatic detection measurement method for the turbine working blade, 3 operators are selected from the programmed measurement program to respectively measure 10 parts for 3 times in the analysis process of the measurement system (5), and the typical sizes of a tenon part, a blade body part and a blade shroud part are selected according to the characteristics of the structure of the blade to analyze the measurement system, and the method is operated according to the following steps by utilizing Minitab software: the statistical/quality tool/gauge research/gauge R & R research, the analysis method selects variance analysis, sets the process tolerance of the corresponding size, selects part number, operator, measurement data, and clicks to determine the corresponding analysis result.

Further, in the final inspection automatic detection measuring method for the turbine working blade, in the (6) measurement stability evaluation process, for the measuring system meeting the use requirement, according to the final inspection measurement size condition, the statistical process stability evaluation is performed on the measurement unstable size; verifying the influence degree of the measurement system and the environment related factors on the data: selecting a part, measuring 2 data every day, wherein the data are measured earlier than the morning and the afternoon, the temperature and humidity requirements during the measurement period meet the requirements, the stability condition of the part is described by using the measurement data of 10 days, and the analysis of a mean value-range control chart is carried out, wherein all points of the mean value and the range of the sample are required to be within the control limit, and the control chart is stable and has no large fluctuation.

Further, in the final inspection automatic detection measurement method for the turbine working blade, in the measurement uncertainty analysis and evaluation process of the step (7), the dimension with the worst tolerance control is selected for the measurement uncertainty analysis and evaluation, and the method comprises the following steps of A-type measurement uncertainty evaluation and B-type measurement uncertainty evaluation: calculating the uncertainty of the measurement according to the measurement data, wherein the result data can be calculated by a probability statistical method, the A-type evaluation of standard uncertainty can be carried out, when the times are enough, the distribution of the measured values should meet normal distribution, but in the actual test measurement process, the times are limited so that the measured values cannot completely meet the normal distribution, but follow t distribution, and in order to achieve the same confidence probability, the measurement deviation range should be expanded and multiplied by the corresponding t distribution t factor; wherein the class A rating for standard uncertainty is:

average value:

the standard deviation of the mean value adopts Bessel formula:

following t distribution, confidence probability 95%, 9 times, looking up table to obtain t_0.95＝2.26

Class a uncertainty:

class B rating of standard uncertainty:

the type B evaluation is calculated by taking the indicating value error of the measuring machine, the measuring machine has a temperature compensation function, and the influence of temperature on the uncertainty is small and can be ignored;

taking the error distribution clothes of the three-coordinate measuring machine with the confidence probability p of 95 percent and the kp of 1.96From uniform distribution, take

Representation of the synthetic standard uncertainty:

when verifying that the uncertainty of the type B and the tolerance ratio meet the relevant requirements, the uncertainty of the measurement of the measuring instrument is specified to meet 1/4, 1/6 and 1/10 grades of the tolerance of the measured part;

and verifying that the ratio of the product tolerance to the measurement uncertainty of the synthesis standard meets relevant requirements, wherein the ratio of the product tolerance to the measurement uncertainty is required to be more than 4: 1.

Further, in the final inspection automatic detection measuring method for the turbine working blade, in the (8) measuring data consistency verification process, a small batch of parts are selected to measure the final inspection size by using an automatic detection method, the consistency of the automatic detection measuring data and the data of the traditional measuring method is verified, and the deviation value distribution conditions of the two measuring modes are analyzed.

Compared with the prior art, the method for automatically detecting and measuring the final inspection of the turbine working blade has the beneficial effects that: the three-coordinate measuring machine and the computer are utilized to realize automatic detection, the turbine working blade is finally inspected and measured in a full size mode, the measuring efficiency can be effectively improved, the operation of a measuring program is stable and reliable, the repeatability, the reproducibility and the consistency of a measuring result are superior to those of a traditional measuring method, and the requirement of batch production is met. Meanwhile, through a large amount of demonstration analysis, tests and summarization, the measuring method is discovered, the problem that the number of inspectors for inspecting the working blades of the turbine is reduced from 5-6 to only 1-2 is solved, and the measuring efficiency is improved by at least 70%. The measuring method can effectively reduce the labor intensity of operators, reduce the design and manufacturing cost of measuring tools, reduce the processing and measuring cost, improve the measuring precision, reduce the measuring error, improve the measuring efficiency and meet the requirement of batch production. The method has the advantages of automatic measurement, high measurement precision, low measurement cost, no need of auxiliary equipment and secondary operation and the like, and has the dual advantages of high measurement precision and high measurement efficiency.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings.

FIG. 1 is a flow chart of the measurement method of the present invention.

Detailed Description

In order to more fully explain the practice of the invention, the invention is further described with reference to the following specific examples. The examples are given solely for the purpose of illustration and are not intended to limit the scope of the invention.

As shown in fig. 1, the automatic detection and measurement method for final inspection of turbine working blades according to the present invention is implemented based on a three-coordinate measuring machine and a computer, wherein the computer is used for controlling the three-coordinate measuring machine and processing measurement data, the measurement method includes determining measurement dimensions, establishing a coordinate system, reading coordinate data, evaluating measurement stability, analyzing a measurement system, programming a measurement program, analyzing and evaluating measurement uncertainty, and verifying consistency of the measurement data, and the specific measurement method includes the following steps:

(1) determining the measurement size: identifying the final inspection and measurement size of the turbine working blade in a pre-programmed process procedure through a three-coordinate measuring machine, wherein except the tooth form and the switching radius in the turbine working blade, all sizes of a blade flange plate, a tenon, a blade crown and a blade body need to be identified, wherein the size of the tooth form part needs to be used for clamping and positioning and does not need to be detected; the transfer radius size cannot be detected in real time by the measurement software in the three-coordinate measuring machine.

(2) Establishing a coordinate system: establishing a coordinate system on a special measuring chuck in a three-coordinate measuring machine, converting the coordinate system to a blade coordinate system through corresponding conversion, aligning through a reference A surface and an upper end surface of a positioning block when establishing a reference coordinate system, so as to realize direction limitation on a Y axis and a Z axis of a blade, namely limiting the degrees of freedom in three directions of an XYZ axis, offsetting corresponding values to a YZ center according to the measured values of the reference A surface and the upper end surface of the positioning block, namely limiting the positions of the Y axis and the Z axis, constructing a corresponding reference point through the reference in the tenon direction of the blade, offsetting a reference point X axis by a corresponding calculated value to the X axis center, and limiting six degrees of freedom, namely finishing the establishment of the coordinate system of the blade; when the batch detection is carried out, the blades need to be arranged in a special measuring chuck, and the front position and the rear position do not exceed 2mm, so that the program in the three-coordinate measuring machine can realize automatic error compensation and measurement.

(3) Reading coordinate data: the method comprises the steps of circularly reading reference measurement coordinate data, dimension measurement point coordinate data and dimension tolerance data through computer high-level programming software, namely, respectively storing the dimension measurement point coordinate, the reference measurement point coordinate, a dimension theoretical value and the tolerance data measured by a blade into corresponding data files HIT.TXT, JZHIT.TXT and NOMTOL.TXT, assigning and programming in a computer by adopting DMIS measurement software, assigning a path where the corresponding data file is located to a corresponding variable, then carrying out a command of opening the file for reading, and circularly reading the data files line by utilizing a WHILE/END WHILE flow control command until all data are read.

(4) And (3) measurement programming: measuring and evaluating the size of a measuring point by using a computer advanced programming assignment statement, and outputting measuring result data; measuring points and evaluating sizes and outputting measurement result data by adopting a computer advanced programming assignment statement; in the whole measuring process of the blade, only one time of circularly reading the file and the high-level statement of the assignment variable is needed to be executed when the program is started, and the corresponding data coordinate is input into the corresponding measuring element, so that the batch detection operation can be realized; in addition, program statements are clear, stable and reliable, and only data file modification can be performed when modification is needed, so that program misoperation is prevented.

(5) Analyzing a measuring system: selecting 3 operators from the compiled measuring program to respectively measure 10 parts for 3 times, simultaneously selecting typical sizes of a tenon part, a blade body part and a blade crown part according to the characteristics of the structure of the blade to analyze the measuring system, utilizing Minitab software, and operating according to the following steps: the statistical/quality tool/gauge research/gauge R & R research, the analysis method selects variance analysis, sets the process tolerance of the corresponding size, selects part number, operator, measurement data, and clicks to determine the corresponding analysis result.

(6) Evaluation of measurement stability: carrying out statistical process stability evaluation on the unstable measurement size according to the measurement system meeting the use requirement and the final inspection measurement size condition; verifying the influence degree of the measurement system and the environment related factors on the data: selecting a part, measuring 2 data every day, wherein the data are measured earlier than the morning and the afternoon, the temperature and humidity requirements during the measurement period meet the requirements, the stability condition of the part is described by using the measurement data of 10 days, and the analysis of a mean value-range control chart is carried out, wherein all points of the mean value and the range of the sample are required to be within the control limit, and the control chart is stable and has no large fluctuation. Carrying out statistical process stability evaluation on the unstable measurement size according to the measurement system meeting the use requirement and the final inspection measurement size condition;

(7) measurement uncertainty analysis and evaluation: selecting the dimension with the strictest tolerance requirement control for measurement uncertainty analysis and evaluation, including evaluation of A-type and B-type measurement uncertainty: calculating the uncertainty of the measurement according to the measurement data, wherein the result data can be calculated by a probability statistical method, the A-type evaluation of standard uncertainty can be carried out, when the times are enough, the distribution of the measured values should meet normal distribution, but in the actual test measurement process, the times are limited so that the measured values cannot completely meet the normal distribution, but follow t distribution, and in order to achieve the same confidence probability, the measurement deviation range should be expanded and multiplied by the corresponding t distribution t factor; wherein the class A rating for standard uncertainty is:

average value:

the standard deviation of the mean value adopts Bessel formula:

following t distribution, confidence probabilityAt 95%, times 9 times, look-up table to obtain t_0.95＝2.26

Class a uncertainty:

class B rating of standard uncertainty:

the type B evaluation is calculated by taking the indicating value error of the measuring machine, the measuring machine has a temperature compensation function, and the influence of temperature on the uncertainty is small and can be ignored;

taking the confidence probability p as 95 percent, kp as 1.96, uniformly distributing the error distribution of the three-coordinate measuring machine, and taking

Representation of the synthetic standard uncertainty:

when verifying that the uncertainty of the type B and the tolerance ratio meet the relevant requirements, the uncertainty of the measurement of the measuring instrument is specified to meet 1/4, 1/6 and 1/10 grades of the tolerance of the measured part;

and verifying that the ratio of the product tolerance to the measurement uncertainty of the synthesis standard meets relevant requirements, wherein the ratio of the product tolerance to the measurement uncertainty is required to be more than 4: 1.

(8) And (3) verifying the consistency of the measured data: and selecting a small batch of parts, measuring the final inspection size by using an automatic detection method, verifying the consistency of the automatic detection measurement data and the data of the traditional measurement method, and analyzing the distribution condition of the deviation values of the two measurement modes.

The protection scope of the present invention is not limited to the technical solutions disclosed in the specific embodiments, the above description is only a preferred embodiment of the present invention, and the present invention is not limited thereto, and any minor modifications, equivalent substitutions and improvements made according to the technical solutions of the present invention should be included in the protection scope of the technical solutions of the present invention.