A blade surface accuracy measurement system and its error analysis method

Abstract

The present application discloses a blade profile precision measurement system and an error analysis method thereof, which relate to the field of blade measurement technology. The system includes an automatic detection integrated application platform, a computer platform and a controller. The automatic detection integrated application platform includes a high-precision actuator, a wide-area mobile platform and an end effector, wherein the high-precision actuator and the wide-area mobile platform are both connected to the controller, the end effector is connected to the computer platform, and the computer platform is connected to the controller. Through the coordinated operation of the high-precision actuator, the wide-area mobile platform and the end effector, the mobile scanning measurement of the blade surface is realized, and the efficiency of the blade measurement is improved. At the same time, by constructing a measurement uncertainty mathematical model to calculate the measurement uncertainty and the expanded uncertainty, combined with the surface point cloud data of the blade to be measured, the external dimensions of the blade to be measured are finally determined. The present application can improve the accuracy of blade parameter measurement and accurately reflect the true processing quality of the blade.

Description

Technical Field

[0001] The present application relates to the field of blade measurement technology, and in particular to a blade profile accuracy measurement system and an error analysis method thereof. Background Art

[0002] The rotor system is the source of a helicopter's lift. Composite blades, as core components of the rotor system, are manufactured with precision that impacts the system's flight performance, safety, and service life. Blade surface accuracy directly impacts the blade's aerodynamic shape and performance. Blades are primarily characterized by large size, low rigidity, and high precision. Currently, traditional blade measurement methods rely on manual operation using measuring instruments such as tape measures, vernier calipers, micrometers, and quadrants to measure key blade characteristics. However, due to the blade's large size, it's impossible to measure dimensions at any given location. Therefore, the only way to control the overall blade quality is by selecting a few key dimensions and then using these key dimensions to assess their machining quality. However, this traditional manual measurement method is inefficient and susceptible to human error, resulting in low blade measurement accuracy and an inability to accurately reflect the blade's true machining quality.

[0003] Therefore, how to improve the accuracy of blade parameter measurement so as to accurately reflect the actual processing quality of the blades has become a technical problem that needs to be solved urgently in this field. Summary of the Invention

[0004] The purpose of this application is to provide a blade profile accuracy measurement system and an error analysis method thereof, which can improve the accuracy of blade parameter measurement and accurately reflect the actual processing quality of the blade.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In the first aspect, the present application provides a blade profile accuracy measurement system, which includes an automatic detection integrated application platform, a computer platform and a controller, and the automatic detection integrated application platform includes a high-precision actuator, a wide-area mobile platform and an end effector, wherein the high-precision actuator and the wide-area mobile platform are both connected to the controller, the end effector is connected to the computer platform, and the computer platform is connected to the controller.

[0007] The end effector is used to scan and measure the surface of the blade to be measured, obtain surface point cloud data of the blade to be measured, and send the surface point cloud data of the blade to be measured to the computer platform.

[0008] The high-precision actuator is used to clamp the end effector to work in coordination with the end effector, so as to expand the reachable space and scanning measurement range of the end effector.

[0009] The wide-area mobile platform is used to carry the high-precision actuator and the end effector, and provide a mobile platform for the high-precision actuator and the end effector, so that the end effector can perform mobile scanning measurement on the blade to be measured.

[0010] The controller is used to control the movement of the wide-area mobile platform and the movement of the high-precision actuator.

[0011] The computer platform is used to construct a mathematical model of measurement uncertainty, and based on the mathematical model of measurement uncertainty, calculate the measurement uncertainty of each error source; and based on the measurement uncertainty, calculate the expanded uncertainty; and determine the external dimensions of the blade to be measured based on the expanded uncertainty and the surface point cloud data of the blade to be measured; wherein, the mathematical model of measurement uncertainty is a mathematical model of all error sources existing in the mobile scanning measurement process of the automatic detection integrated application platform; the error sources include the movement error of the high-precision actuator on the wide-area mobile platform, the positioning error of the high-precision actuator, the installation error when clamping the end effector, the measurement error of the end effector and the calculation error of the algorithm based on the mathematical model of measurement uncertainty; the measurement uncertainty is a parameter that characterizes the error size of the error source, and the expanded uncertainty is a parameter that takes into account the expansion factor and is related to the confidence level of the measurement uncertainty.

[0012] Optionally, the blade profile accuracy measurement system further includes a herringbone fixture, and the high-precision actuator clamps the end effector through the herringbone fixture.

[0013] Optionally, the expression of the measurement uncertainty mathematical model is:

[0014]

[0015] Where u represents the measurement uncertainty; i and j represent the error source i and error source j respectively, u i and u jdenote the measurement uncertainty of error source i and error source j, i = 1, 2, 3, 4, j = 1, 2, 3, 4, respectively; u1 denotes the movement uncertainty of the high-precision actuator on the wide-area mobile platform; u2 denotes the positioning uncertainty of the high-precision actuator; u3 denotes the installation uncertainty of the herringbone fixture holding the end effector during the measurement process; u4 denotes the measurement uncertainty of the end effector; u5 denotes the uncertainty of the algorithm based on the mathematical model itself; Cov(·) denotes the covariance;

[0016] The expression of the expanded uncertainty is:

[0017] U = k × u;

[0018] Where U represents the expanded uncertainty and k is the expansion factor;

[0019] The expression of the outer dimensions of the blade to be measured is:

[0020] X=x l ±U;

[0021] Among them, X represents the final size of the blade to be tested, x l It represents the external dimensions obtained by directly measuring the surface point cloud data of the blade to be tested.

[0022] Optionally, the automatic detection integrated application platform also includes a global positioning reference, which is used to use the cross-section of the central axis of the two boring holes at the root of the blade to be measured as a reference plane, and unify the high-precision actuator, the wide-area mobile platform and the end effector into the same global coordinate system corresponding to the reference plane for measurement operations.

[0023] Optionally, the end effector is a laser scanner or a line laser measuring instrument.

[0024] Optionally, the line laser measuring instrument is a line laser measuring instrument of model LJ-X8900.

[0025] Optionally, the wide-area mobile platform is an AGV trolley or a mobile guide rail.

[0026] Optionally, the high-precision actuator is an ABB industrial robot.

[0027] In a second aspect, the present application proposes an error analysis method based on the blade profile accuracy measurement system described in the first aspect. The error analysis method for the blade profile accuracy measurement system includes:

[0028] Performing mobile scanning measurement on the surface of the blade to be measured to obtain surface point cloud data of the blade to be measured;

[0029] Constructing a mathematical model of measurement uncertainty;

[0030] Calculating the measurement uncertainty of each error source according to the measurement uncertainty mathematical model;

[0031] Based on the measurement uncertainty, the expanded uncertainty is calculated;

[0032] The outer dimensions of the blade to be measured are determined according to the expanded uncertainty and the surface point cloud data of the blade to be measured.

[0033] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0034] The present application provides a blade profile precision measurement system and its error analysis method. By designing an automatic detection integrated application platform including a high-precision actuator, a wide-area mobile platform, and an end effector, and through the coordinated cooperation between the high-precision actuator, the wide-area mobile platform, and the end effector, it is possible to realize that the wide-area mobile platform carries the high-precision actuator, and the high-precision actuator clamps the end effector for mobile scanning measurement, thereby realizing mobile scanning measurement of large-sized and large-volume blades, thereby improving measurement efficiency. At the same time, a measurement uncertainty mathematical model is constructed through a computer platform, and the measurement uncertainty of each error source is calculated based on the measurement uncertainty mathematical model, and then the expanded uncertainty is calculated. Therefore, the final external dimensions of the blade to be measured can be determined by combining the expanded uncertainty and the surface point cloud data of the blade to be measured collected by the end effector. By constructing a mathematical model of measurement uncertainty and introducing parameters such as measurement uncertainty and expanded uncertainty, the influence of various error sources in the measurement process on the system measurement results is fully considered, thereby effectively improving the accuracy of blade parameter measurement and accurately reflecting the true processing quality of the blades, solving the problems of low efficiency, low accuracy and inability to accurately reflect the true processing quality of the blades in traditional manual measurement methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 A schematic diagram of the structure of an automatic detection integrated application platform provided in one embodiment of the present application.

[0037] Figure 2 A schematic structural diagram of a blade profile accuracy measurement system provided in one embodiment of the present application.

[0038] Figure 3 A flowchart of an error analysis method for a blade profile accuracy measurement system provided in one embodiment of the present application.

[0039] Figure 4 A schematic diagram of an error analysis method for a blade profile accuracy measurement system provided in one embodiment of the present application.

[0040] Figure 5 A schematic diagram of the reference plane position provided in one embodiment of the present application. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0042] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0043] like Figure 1 and Figure 2 As shown, this embodiment provides a blade profile accuracy measurement system, which includes an automatic detection integrated application platform, a computer platform and a controller. Figure 1 As shown, the automatic detection integrated application platform includes a high-precision actuator, a wide-area mobile platform and an end effector, wherein the high-precision actuator and the wide-area mobile platform are both connected to the controller, the end effector is connected to the computer platform, and the computer platform is connected to the controller.

[0044] In this embodiment, the end effector is used to scan and measure the surface of the blade to be measured, obtain surface point cloud data of the blade to be measured, and send the surface point cloud data of the blade to be measured to the computer platform.

[0045] In this embodiment, the high-precision actuator is used to clamp the end effector to work in coordination with the end effector, so as to expand the reachable space and scanning measurement range of the end effector.

[0046] In this embodiment, the blade profile accuracy measurement system further includes a herringbone-shaped fixture. Specifically, the high-precision actuator clamps the end effector through the herringbone-shaped fixture.

[0047] In this embodiment, the wide-area mobile platform is used to carry the high-precision actuator and the end effector, and provide a mobile platform for the high-precision actuator and the end effector, so that the end effector can perform mobile scanning measurement on the blade to be measured.

[0048] In this embodiment, the controller is used to control various actions of the wide-area mobile platform and various actions of the high-precision actuator, etc.

[0049] In this embodiment, the computer platform is mainly used to construct a mathematical model of measurement uncertainty, and calculate the measurement uncertainty of each error source based on the mathematical model of measurement uncertainty; and calculate the expanded uncertainty based on the measurement uncertainty; and determine the external dimensions of the blade to be measured based on the expanded uncertainty and the surface point cloud data of the blade to be measured; wherein, the mathematical model of measurement uncertainty is a mathematical model of all error sources existing in the mobile scanning measurement process of the automatic detection integrated application platform; the error sources include the movement error of the high-precision actuator on the wide-area mobile platform, the positioning error of the high-precision actuator, the installation error when clamping the end effector, the measurement error of the end effector and the calculation error of the algorithm based on the mathematical model of measurement uncertainty; the measurement uncertainty is a parameter that characterizes the error size of the error source, and the expanded uncertainty is a parameter that takes into account the expansion factor and is related to the confidence level of the measurement uncertainty.

[0050] In this embodiment, the automatic detection integrated application platform also includes a global positioning reference, which is used to use the cross-section of the central axis of the two boring holes at the root of the blade to be measured as a reference plane, and unify the high-precision actuator, the wide-area mobile platform and the end effector into the same global coordinate system corresponding to the reference plane for measurement operations.

[0051] In this embodiment, the end effector may be a laser scanner or a line laser measuring instrument, etc. The line laser measuring instrument is preferably a line laser measuring instrument of the LJ-X8900 model.

[0052] In this embodiment, the high-precision actuator is preferably an ABB industrial robot.

[0053] In this embodiment, the wide-area mobile platform may be an AGV or a mobile guide rail, etc. In this embodiment, a mobile guide rail dedicated to industrial robots with a specification model of IRBT 2005 is preferred.

[0054] In this embodiment, an automatic detection integrated application platform is designed to meet the automatic measurement needs of large-size composite blades. It specifically includes four parts: a high-precision actuator, a wide-area mobile platform, an end effector, and a global positioning reference. The first three parts are combined into an intelligent measurement component, and the global positioning reference ensures the high accuracy of the overall measurement.

[0055] In this embodiment, the end effector primarily includes various optical non-contact measurement devices, such as laser scanners, line laser measuring instruments, and line laser sensors, which acquire surface information of the object being measured and perform measurements in a non-contact manner. High-precision actuators, such as various industrial robots or collaborative industrial robots, clamp the end effector and work in conjunction with it. Their flexibility in movement within a certain spatial range expands the reach of the end effector and thus the scanning and measurement range. Wide-area mobile platforms, such as AGVs and mobile guides, possess more powerful planar motion capabilities. Equipped with high-precision actuators and end effectors, they can perform automated scanning and measurement of large-scale objects such as aircraft fuselages and rotor blades. Relying on a global positioning reference, the wide-area mobile platform, high-precision actuator, and end effector are unified in a global coordinate system, allowing the overall measurement results of large-scale objects to be obtained by compositing local measurements.

[0056] In this embodiment, the rotor blade is long and narrow as a whole, and can reach 7 to 8 meters in a single direction, which is a large-scale product. A series of specific sections of the blade are selected for blade shape detection, and the overall shape quality is controlled by cross-section shape detection. Based on the characteristics of the long and narrow blade shape and the fact that blade shape detection is based on cross-sections, an automatic measurement system for blade shape detection is built. Figure 2 As shown, the blade profile accuracy measurement system of this embodiment mainly includes an industrial robot moving guide rail, an ABB industrial robot, a herringbone fixture and an LJ-X8900 line laser measuring instrument. The instrument error is composed of the instrument errors of the four components of the measurement system.

[0057] In this embodiment, an LJ-X8900 line laser measuring instrument emits a line laser. A sensor receives the return laser signal, generating a series of point coordinates to determine the distance between the sensor and the blade being measured. An ABB industrial robot serves as a high-precision actuator. A herringbone-shaped tool is mounted at the end of the robot, with a line laser measuring instrument attached at each end to measure the cross-sectional shape of both sides of the blade. The robot's movable guide rails carry the robot along the length of the blade, capturing the cross-sectional shape at different locations. Finally, automated measurement is achieved through the integration of a controller and a computer platform.

[0058] In an exemplary embodiment, based on the above-mentioned blade profile accuracy measurement system, an error analysis method corresponding to the blade profile accuracy measurement system is provided, such as Figure 3As shown in FIG, the error analysis method mainly includes the following steps:

[0059] Step S1: Perform mobile scanning measurement on the surface of the blade to be measured to obtain surface point cloud data of the blade to be measured.

[0060] Step S2: Construct a mathematical model of measurement uncertainty.

[0061] Step S3: Calculate the measurement uncertainty of each error source according to the measurement uncertainty mathematical model.

[0062] Step S4: Calculate the expanded uncertainty based on the measurement uncertainty.

[0063] Step S5: determining the outer dimensions of the blade to be measured according to the expanded uncertainty and the surface point cloud data of the blade to be measured.

[0064] like Figure 4 As shown, the error analysis method corresponding to the blade profile accuracy measurement system in this embodiment includes the following steps:

[0065] (1) Identify the main error sources.

[0066] In this embodiment, according to the blade measurement and size extraction process, it can be seen that the main error sources are instrument errors in the process of measuring and obtaining the blade point cloud and algorithm errors in extracting the size based on the point cloud model template.

[0067] The meaning of measurement uncertainty is a parameter that evaluates the degree of uncertainty in a measurement result. It is also a reasonable assessment of the range within which the theoretical value of the measurement result lies. It links the ultimate rationality of the measured result with the measurement uncertainty.

[0068] During the measurement process, five main factors affect the standard uncertainty of measurement: the industrial robot's guide rails, the industrial robot, the herringbone fixture, the line laser measuring instrument, and the algorithm's computational errors. The measurement uncertainty of each component was specifically analyzed to construct a measurement system error model.

[0069] (2) Construct a mathematical model of measurement uncertainty.

[0070] In this embodiment, the uncertainty of measurement is determined by the method of synthetic standard uncertainty. Considering the correlation between the components of the automatic measurement system and the relative independence of the algorithm uncertainty, the covariance between the components of the measurement system is introduced when calculating the uncertainty of measurement.

[0071] According to the above analysis, the mathematical model expression of measurement uncertainty is as follows:

[0072]

[0073] Where u represents the measurement uncertainty; i and j represent the error source i and error source j respectively, u i and u j represents the measurement uncertainty of error source i and error source j, respectively, where i = 1, 2, 3, 4, and j = 1, 2, 3, 4; u1 represents the motion uncertainty of the high-precision actuator on the wide-area mobile platform, which in this embodiment is the motion uncertainty of the industrial robot on the mobile guideway; u2 represents the positioning uncertainty of the high-precision actuator, which in this embodiment is the positioning uncertainty of the industrial robot; u3 represents the installation uncertainty of the zigzag fixture holding the end effector during measurement, which in this embodiment is the installation uncertainty of the zigzag fixture holding the line laser measuring instrument; and u4 represents the measurement uncertainty of the end effector, which in this embodiment is the measurement uncertainty of the line laser measuring instrument. Covariance represents the influence of the relationship between two error sources on the measurement uncertainty. This influence is mutual, meaning that while considering the influence of error source i on error source j, the influence of error source j on error source i must also be considered. Error sources include the industrial robot mobile guideway, the industrial robot, the zigzag fixture, the line laser measuring instrument, and the computational errors of the algorithm. When this bidirectional effect is incorporated into the mathematical model of measurement uncertainty, the total contribution of the covariance term is doubled. u5 represents the uncertainty of the algorithm based on the mathematical model, and Cov(·) represents the covariance.

[0074] (3) Uncertainty analysis of each component.

[0075] In this embodiment, the uncertainty of each component of the blade automatic measurement system is analyzed based on the tasks each component performs in the overall measurement scheme. The blade measurement scheme is as follows: The blade shape detection requirement is to use the cross section Z0 of the center axis passing through the two boring holes at the root of the blade as the reference plane. The specific position of the reference plane is as follows: Figure 5 The Z0 section is the plane passing through the center lines of the two boring holes at the blade tip, and the span direction of the blade is the Z axis direction. Figure 5 The Z8430 section, defined as the section 8430mm from the Z0 plane in the Z-axis direction, uses the industrial robot's mobile guideway as the spanwise reference axis. Prior to measurement, the Z0 plane is calibrated on the industrial robot's guideway. A herringbone fixture mounted on the end of the industrial robot clamps two linear laser measuring instruments, which move linearly along the guideway to scan and measure specific sections relevant to blade profile accuracy. Because the two linear laser measuring instruments operate simultaneously, a complete cross-sectional point cloud can be acquired from a single station. This acquired cross-sectional point cloud is analyzed and processed to ultimately obtain the required dimensional data.

[0076] According to the above solution provided in this embodiment, further analysis of each component may produce the following errors during the measurement process:

[0077] 1) The movement uncertainty u1 of the high-precision actuator on the wide-area mobile platform, that is, the movement uncertainty u1 of the mobile guide rail.

[0078] In this embodiment, an industrial robot is used as the high-precision actuator, and a mobile guide rail is used as the wide-area mobile platform. The movement uncertainty u1 of the mobile guide rail is mainly composed of the calibration error during the installation of the mobile guide rail and the repeat positioning error of the mobile guide rail itself. The main reason for the installation and calibration error is that the solution is to clamp the blades with a fixed tool and calibrate the installation of the industrial robot's mobile guide rail to ensure that the direction of the industrial robot's mobile guide rail is parallel to the blade span direction (i.e., the normal direction of the reference plane Z0). The error generated during the installation and calibration process is represented by v1. At the same time, when the industrial robot moves on the mobile guide rail, considering the accuracy of the repeat positioning of the guide rail itself, the positioning error generated is represented by v2.

[0079] In this embodiment, the movement uncertainty u1 of the moving guide rail can be further refined into the following expression:

[0080] u1=v1+v2 (2).

[0081] Among them, u1 represents the movement uncertainty of the high-precision actuator on the wide-area mobile platform, that is, the movement uncertainty of the industrial robot on the mobile guide rail, v1 represents the error generated during the installation and calibration process, and v2 represents the positioning error caused by the accuracy of the guide rail's own repeated positioning when the industrial robot moves on the mobile guide rail.

[0082] 2) The positioning uncertainty u2 of the high-precision actuator, that is, the positioning uncertainty u2 of the industrial robot.

[0083] In this embodiment, the industrial robot maintains a consistent linear position on the movable guide rail during measurement. Since the industrial robot must return to a safe position when not in operation, each measurement task requires moving to the initial point on the guide rail and adjusting to the working position. Positioning errors in the industrial robot primarily occur during the transition from the safe position to the initial working position and can be directly represented by u2.

[0084] 3) The installation uncertainty u3 of the herringbone fixture that clamps the end effector during the measurement process, that is, the installation uncertainty u3 of the herringbone fixture.

[0085] In this embodiment, a herringbone fixture is fixedly connected to the end of the industrial robot, with two line laser measuring instruments installed at each end to perform scanning tasks. The cross-sectional point cloud of the blade is composed of point clouds scanned by the two line laser measuring instruments, and most dimensional features involve point clouds from both cross-sectional areas. Therefore, errors from both line laser measuring instruments are cumulative and affect the final result.

[0086] In this embodiment, the installation uncertainty u3 of the herringbone fixture can be further refined into the following expression:

[0087] u3=w1+w2 (3).

[0088] Among them, u3 represents the installation uncertainty of the herringbone fixture holding the end effector during the measurement process, that is, the installation uncertainty of the herringbone fixture holding the line laser measuring instrument during the measurement process, and w1 and w2 represent the installation errors of the left and right side line laser measuring instruments, respectively.

[0089] 4) The measurement uncertainty u4 of the end effector, that is, the measurement uncertainty u4 of the line laser measuring instrument.

[0090] In this embodiment, the end effector uses a line laser measuring instrument. The line laser measuring instruments on both sides are of the same model and have the same measurement uncertainty when operating normally. Since the cross-sectional point cloud of the blade is composed of point clouds scanned by the left and right line laser measuring instruments respectively, and most of the dimensional features involve the point clouds of the cross-sections on both sides at the same time, the measurement errors of the line laser measuring instruments on both sides will be superimposed and affect the final result at the same time.

[0091] In this embodiment, the measurement uncertainty u4 of the line laser measuring instrument is actually twice the measurement uncertainty of a single line laser measuring instrument, and is expressed as follows:

[0092] u4=2x (4).

[0093] Wherein, u4 represents the measurement uncertainty of the end effector, which is the measurement uncertainty of the line laser measuring instrument in this embodiment, and x represents the measurement uncertainty of a single end effector.

[0094] (4) Determine the expanded uncertainty.

[0095] For the combined standard uncertainty of measurement, the expanded uncertainty of measurement is further calculated. The expanded uncertainty is a quantity that determines the interval of the measurement result, which provides the confidence range of the measurement result. Specifically, the expanded uncertainty can be defined as:

[0096] U=k×u (5).

[0097] Where U represents the expanded uncertainty, u represents the measurement uncertainty, and k is the expansion factor, which is related to the confidence level of the measurement uncertainty. In this embodiment, the confidence level of the measurement uncertainty is taken as 95%, and the corresponding expansion factor k=2. Therefore, the mathematical model of the expanded uncertainty of the measurement is expressed as:

[0098]

[0099] Where U represents the expanded uncertainty, i and j represent the error source i and error source j respectively, u i and u j They represent the measurement uncertainty of error source i and the measurement uncertainty of error source j respectively, and u5 represents the uncertainty of the algorithm based on the mathematical model itself.

[0100] (5) Reflect measurement uncertainty in the evaluation report results and analyze the impact of measurement uncertainty on the results.

[0101] In this embodiment, the evaluation report is a report that evaluates the results of the measurement system's measurement of the blade's shape. In the final evaluation report, the influence of measurement uncertainty is taken into account. The evaluation report reflects the final measured blade's shape dimension results with measurement uncertainty, which should be expressed as:

[0102] X=x l ±U (7).

[0103] Where X represents the final dimensional result of the blade to be tested, that is, the dimensional result presented in the final evaluation report taking into account various errors. The evaluation report directly reflects the expanded uncertainty and indirectly reflects the measurement uncertainty. l It represents the external dimensions obtained by directly measuring the surface point cloud data of the blade to be measured, that is, the external dimensions obtained by extracting the measurement point cloud through an algorithm. This is actually the external dimensions result directly measured by mobile scanning measurement without considering various errors. U represents the expanded uncertainty.

[0104] This embodiment not only proposes a blade profile accuracy measurement system, but also provides a corresponding error analysis method. First, based on the solution for large-scale composite blade profile accuracy measurement, the components of the measurement system are analyzed. The measurement system refers to the blade profile accuracy measurement system. Then, all links in the blade profile accuracy measurement system that may cause errors during the measurement process are analyzed and determined, thereby determining all existing error sources and constructing a mathematical model of the system measurement uncertainty. Then, the impact of each error source on the overall measurement uncertainty is analyzed separately, and the variables and expressions that need to be considered are given. Finally, the impact of the uncertainty of the system measurement on the measurement results is analyzed and summarized.

[0105] This embodiment designs an integrated automatic detection application platform and builds a digital automatic measurement system for the application scenario of large-scale composite blade surface precision measurement. Compared with traditional measurement methods, it improves measurement efficiency and stability while ensuring accuracy. The system measurement error sources are determined based on the specific components of the system, and a mathematical model of the system measurement uncertainty is constructed. By analyzing the measurement uncertainty of each error source one by one, the overall measurement accuracy is controlled and the reliability of the measurement results is guaranteed.

[0106] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0107] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A blade profile accuracy measurement system, characterized in that: The blade profile accuracy measurement system includes an automatic detection integrated application platform, a computer platform, and a controller. The automatic detection integrated application platform includes a high-precision actuator, a wide-area mobile platform, and an end effector. The high-precision actuator and the wide-area mobile platform are both connected to the controller, the end effector is connected to the computer platform, and the computer platform is connected to the controller. The end effector is used to scan and measure the surface of the blade to be measured, obtain surface point cloud data of the blade to be measured, and send the surface point cloud data of the blade to be measured to the computer platform; The high-precision actuator is used to clamp the end effector to work in coordination with the end effector to expand the reachable space and scanning measurement range of the end effector; The wide-area mobile platform is used to carry the high-precision actuator and the end effector, and provide a mobile platform for the high-precision actuator and the end effector, so that the end effector can perform mobile scanning measurement on the blade to be measured; The controller is used to control the movement of the wide-area mobile platform and the movement of the high-precision actuator; The computer platform is used to construct a mathematical model of measurement uncertainty, and based on the mathematical model of measurement uncertainty, calculate the measurement uncertainty of each error source; and based on the measurement uncertainty, calculate the expanded uncertainty; and determine the external dimensions of the blade to be measured based on the expanded uncertainty and the surface point cloud data of the blade to be measured; wherein, the mathematical model of measurement uncertainty is a mathematical model of all error sources existing in the mobile scanning measurement process of the automatic detection integrated application platform; the error sources include the movement error of the high-precision actuator on the wide-area mobile platform, the positioning error of the high-precision actuator, the installation error when clamping the end effector, the measurement error of the end effector and the calculation error of the algorithm based on the mathematical model of measurement uncertainty; the measurement uncertainty is a parameter that characterizes the error size of the error source, and the expanded uncertainty is a parameter that takes into account the expansion factor and is related to the confidence level of the measurement uncertainty.

2. The blade profile accuracy measurement system according to claim 1, characterized in that: The blade profile accuracy measurement system further includes a herringbone-shaped fixture, and the high-precision actuator clamps the end effector through the herringbone-shaped fixture.

3. The blade profile accuracy measurement system according to claim 2, characterized in that: The expression of the measurement uncertainty mathematical model is: Where u represents the measurement uncertainty; i and j represent the error source i and error source j respectively, u i and u j denote the measurement uncertainty of error source i and error source j, i = 1, 2, 3, 4, j = 1, 2, 3, 4, respectively; u1 denotes the movement uncertainty of the high-precision actuator on the wide-area mobile platform; u2 denotes the positioning uncertainty of the high-precision actuator; u3 denotes the installation uncertainty of the herringbone fixture holding the end effector during the measurement process; u4 denotes the measurement uncertainty of the end effector; u5 denotes the uncertainty of the algorithm based on the mathematical model itself; Cov(·) denotes the covariance; The expression of the expanded uncertainty is: U = k × u; Where U represents the expanded uncertainty and k is the expansion factor; The expression of the outer dimensions of the blade to be measured is: X=x l ±U; Among them, X represents the final size of the blade to be tested, x l It represents the external dimensions obtained by directly measuring the surface point cloud data of the blade to be tested.

4. The blade profile accuracy measurement system according to claim 1, characterized in that: The automatic detection integrated application platform also includes a global positioning reference, which is used to use the cross-section of the central axis of the two boring holes at the root of the blade to be measured as a reference plane, and unify the high-precision actuator, the wide-area mobile platform and the end effector into the same global coordinate system corresponding to the reference plane for measurement operations.

5. The blade profile accuracy measurement system according to claim 1, characterized in that: The end effector is a laser scanner or a line laser measuring instrument.

6. The blade profile accuracy measurement system according to claim 5, characterized in that: The line laser measuring instrument is a line laser measuring instrument of the LJ-X8900 model.

7. The blade profile accuracy measurement system according to claim 1, characterized in that: The wide-area mobile platform is an AGV trolley or a mobile guide rail.

8. The blade profile accuracy measurement system according to claim 1, characterized in that: The high-precision actuator is an ABB industrial robot.

9. An error analysis method based on the blade profile accuracy measurement system according to any one of claims 1 to 8, characterized in that: The error analysis method comprises: Performing mobile scanning measurement on the surface of the blade to be measured to obtain surface point cloud data of the blade to be measured; Constructing a mathematical model of measurement uncertainty; Calculating the measurement uncertainty of each error source according to the measurement uncertainty mathematical model; Based on the measurement uncertainty, the expanded uncertainty is calculated; The outer dimensions of the blade to be measured are determined according to the expanded uncertainty and the surface point cloud data of the blade to be measured.

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