High-precision propeller mass center position measuring device and method

Abstract

The invention provides a high-precision propeller mass center position measuring device and method.The device comprises a supporting platform assembly, a propeller lifting mechanism and a measuring assembly, the supporting platform assembly comprises a platform supporting base and a supporting seat, and a center hole is formed in the top of the supporting seat; the propeller lifting mechanism is fixed on the inner side of the supporting seat, and the output end of the propeller lifting mechanism can extend upwards along the center hole and is matched with a to-be-tested propeller; the measuring assembly comprises three high-precision force measuring units which are distributed on the same circumference of the top of the supporting seat in a regular triangle shape, and the propeller blades make contact with the three high-precision force measuring units by lifting the propeller to be measured. By measuring the force distribution data of the propeller in different spatial orientations, establishing a measurement model based on the statics equilibrium principle and solving the center-of-mass coordinates by using an optimization algorithm, full-automatic high-precision measurement of the propeller center-of-mass is realized, the method has the advantages of reliability, high measurement efficiency and the like, and a reliable means is provided for static equilibrium adjustment and performance evaluation of the propeller.

Description

Technical Field

[0001] This invention relates to the field of aircraft component testing and precision measurement technology, and in particular to a high-precision propeller center of mass position measurement device and method. Background Technology

[0002] As a key component of an aircraft, the accurate measurement of the propeller's center of mass is crucial for ensuring the aircraft's dynamic balance performance. Traditional propeller center of mass measurement primarily employs the guide rail static balancing method. While simple and easy to implement, this method has the following significant technical limitations: 1. Measurement accuracy is greatly affected by mechanical friction, making it difficult to meet the high-precision requirements of modern aerospace industry; 2. The measurement process relies on the operator's experience, resulting in poor repeatability of the results; 3. For large or specially structured propellers, there are safety hazards during installation and measurement.

[0003] With the development of aviation technology, higher requirements have been placed on the accuracy and efficiency of propeller center of mass measurement, and there is an urgent need to develop a device and method that can achieve high-precision and automated measurement of the propeller center of mass position. Summary of the Invention

[0004] The purpose of this invention is to provide a high-precision propeller centroid position measuring device and method, which can solve the problems of low measurement accuracy and poor efficiency of traditional measuring devices and methods.

[0005] On one hand, the present invention provides a high-precision propeller center of mass position measuring device, characterized in that it includes: a support platform assembly, a propeller lifting mechanism, and a measuring assembly. The support platform assembly includes a platform support base and a support seat fixed to its surface, and the top of the support seat has a central hole; The propeller lifting mechanism is fixed to the inner side of the support base, and its output end can extend upward along the central hole and be adapted to the mounting part of the propeller to be tested. The measuring component includes three high-precision force measuring units, which are fixed in an equilateral triangle on the same circumference concentric with the central hole on the top of the support base. The propeller under test can be raised and lowered by the propeller lifting mechanism so that the roots of its three blades contact the heads of the three high-precision force measuring units respectively.

[0006] Preferably, the support base includes a base plate, two vertical plates arranged at intervals, and a top plate. The base plate is fixed to the surface of the platform support base. The bottom ends of the two vertical plates are perpendicularly connected to the base plate. The bottom of the top plate is perpendicularly connected to the top ends of the two vertical plates. The central hole is opened at the center of the top plate. The propeller lifting mechanism is fixed to the surface of the base plate and located between the two vertical plates. Its output end can extend upward through the central hole.

[0007] Preferably, the propeller lifting mechanism includes a housing, a servo motor, a drive assembly, and a lifting column. The two sides of the housing are fixed to the base plate, and the drive assembly can output the rotation of the servo motor around the horizontal axis as the lifting motion of the lifting column relative to the support base.

[0008] Preferably, the lifting column is a threaded column, and a limiting groove is formed on the surface of the lifting column along its length. The driving assembly includes a worm and a worm wheel that meshes with it, with their axes of rotation perpendicular to each other. The worm is connected to the output shaft of the servo motor and rotates with it. The two ends of the worm wheel are rotatably engaged with the housing through bearings, thereby enabling the worm wheel to rotate with the worm. The inner wall of the central hole of the worm wheel is provided with an internal thread that engages with the lifting column, and a limiting key is provided between the two to engage with the limiting groove, so that the lifting column can only rise and fall relative to the worm wheel.

[0009] Preferably, the top of the lifting column is provided with a transition plane, and the edge of the transition plane is provided with multiple screw holes.

[0010] Preferably, the mounting part of the propeller to be tested can be connected to the adapter plane through an adapter flange, one end of which is a flange with a screw hole, and the other end face is provided with a protruding conical opening.

[0011] Preferably, the bottom of the platform support base is equipped with 4 to 6 leveling supports for adjusting the levelness of the platform support base surface.

[0012] Preferably, the top plate surface has an annular groove concentric with the central hole, and the annular groove has three evenly spaced mounting holes, the bottom ends of the three high-precision force measuring units are respectively fixed in the mounting holes.

[0013] Preferably, it also includes a data acquisition and processing module, which includes a 24-bit high-precision data acquisition card and an industrial computer, which are used for signal acquisition and centroid coordinate calculation, respectively.

[0014] On the other hand, the present invention also provides a high-precision propeller centroid position measurement method based on the above-mentioned device, comprising the following steps: S1: System initial calibration S11: Accurately determine the spatial coordinates of the measuring components to ensure the accurate initial position of the high-precision force measuring unit and the propeller lifting mechanism; S12: Perform zero-point calibration and sensitivity calibration on three high-precision force measuring units, and trace the force value through a standard mass block to ensure measurement accuracy; S13: Force values ​​are calibrated using standard mass blocks to ensure accurate and reliable data acquisition; S2: Specimen Installation and Positioning S21: Install the propeller to be tested at the output end of the propeller lifting mechanism via an adapter flange; S22: Adjust the position of the three propeller blades so that they are respectively within the support range of the three high-precision force measurement units; S23: Check the contact status between each force measuring unit and the propeller to ensure measurement reliability; S3: Measurement Data Acquisition and Processing S31: After the contact between each blade of the propeller is stable, the output data of all high-precision force measurement units are collected synchronously, the collected data is uploaded to the calculation software, and the dedicated analysis software is run for data processing. S32: Record the environmental temperature and humidity parameters that affect the measurement results; S4: Centroid Coordinate Calculation S41: Based on the principle of static equilibrium, the measurement equations are established, where the total gravity equilibrium equation is: F a + F b + F c = G, Among them, a, b, and c are three high-precision force measuring units. A virtual three-dimensional coordinate system is established on the top plane of the support base, and the contact position (X) of the three high-precision force measuring units is accurately measured. a Y a ), (X) b Y b ), (X) c Y c G is the total weight of the propeller, F is the total weight of the propeller. a F b F c Readings for each force measuring unit; S42: The least squares method is used to solve the system of equations to obtain the best estimate of the centroid coordinates. After conversion, the final centroid coordinate formula is obtained, including the torque balance equation: F a ·X a + F b ·X b + F c ·X c = G·Xc F a ·Y a + F b ·Y b + F c ·Y c = G·Y c , centroid coordinates (X) g Y g ),but X g =(F a ·X a +F b ·X b +F c ·X c ) / (F a + F b + F c ) Y g =(F a ·Y a +F b ·Y b +F c ·Y c ) / (F a + F b + F c ); S5: Measurement Result Verification and Output S51: Perform multiple repeated measurements and calculate measurement repeatability; S52: Cross-comparison verification by changing the measurement orientation; S53: Generate a detailed measurement report, including centroid coordinates, uncertainty analysis, and data quality assessment; S54: Outputs a 3D centroid location diagram and a measurement data table.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. Automated measurement process: Traditional methods require multiple manual adjustments and repeated trials, which is cumbersome and time-consuming. A single measurement usually takes more than 30 minutes. This invention realizes a fully automated measurement process, from data acquisition to result analysis, which can be completed automatically. The time for a single measurement is shortened to less than 10 minutes, which significantly improves the detection efficiency and reduces the technical threshold for operators. (2) High measurement accuracy: Traditional methods are limited by the frictional resistance of mechanical guide rails and human reading errors, and their measurement accuracy can usually only reach the millimeter level. This invention adopts a high-precision force measuring unit, and through digital acquisition and automatic processing, it eliminates the influence of human error and mechanical friction, and improves the measurement accuracy to ±0.1mm, which is an order of magnitude higher. (3) Wide applicability to engineering: Traditional methods have strict requirements on the installation posture of propellers and are not suitable for large or special propellers. This invention adopts a vertical measurement method, which can adapt to propellers of different specifications and structures through flexible support and automatic leveling. It solves the limitations of traditional methods in terms of application scope and provides a universal solution for the measurement of the center of mass of various propellers.

[0016] Through the above three technical improvements, this invention not only significantly improves measurement accuracy and efficiency, but also greatly expands the engineering applicability of the method, providing a more advanced and reliable technical means for the precise balancing of propellers. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a three-dimensional structural diagram of the device of the present invention; Figure 2 This is a schematic diagram of the structure of the support platform component in the device of the present invention; Figure 3 This is a schematic diagram of the overall structure of the propeller lifting mechanism in the device of the present invention; Figure 4 This is an exploded view of the internal structure of the propeller lifting mechanism in the device of the present invention; Figure 5 This is a schematic diagram showing the installation of the worm gear, worm, and lifting rod in the device of the present invention; Figure 6 This is a schematic diagram of the transition flange in the device of the present invention; Figure 7 This is an application effect diagram of using the device of the present invention to measure the position of the propeller's center of mass; Explanation of reference numerals in the attached figures: 1: Support platform assembly; 11: Platform support base; 12: Support seat; 121: Base plate; 122: Vertical plate; 123: Top plate; 124: Annular groove; 125: Mounting hole; 13: Center hole; 14: Leveling support; 2: Measuring assembly; 3: Propeller lifting mechanism; 31: Lifting column; 32: Adapter platform; 33: Servo motor; 34: Housing; 35: Limiting groove; 36: Worm gear; 37: Worm wheel; 38: Flexible coupling; 39: Bearing; 4: Propeller under test; 5: Adapter flange; 51: Conical opening. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] like Figure 1-7As shown, the present invention provides a high-precision propeller center of mass position measuring device, comprising: a support platform assembly 1, a propeller lifting mechanism 3, and a measuring component 2. The support platform assembly 1 is assembled from a high-strength steel structure and includes a platform support base 11 and a support seat 12 fixed to its surface. The top of the support seat 12 has a central hole 13. The propeller lifting mechanism 3 is fixed to the inner side of the support seat 12, and its output end can extend upward along the central hole 13 and be adapted to the mounting part of the propeller 4 to be measured. The measuring component 2 includes three high-precision force measuring units, which are arranged in an equilateral triangle and fixed on the same circumference concentric with the central hole 13 on the top of the support seat 12. The propeller lifting mechanism 3 can lift and lower the propeller 4 to be measured so that the roots of its three blades contact the heads of the three high-precision force measuring units respectively.

[0023] Specifically, the support base 12 includes a base plate 121, two vertical plates 122 arranged at intervals, and a top plate 123. The base plate 121 is fixed to the surface of the platform support base 11. The bottom ends of the two vertical plates 122 are vertically connected to the base plate 121 by screws. The bottom of the top plate 123 is vertically connected to the top ends of the two vertical plates 122 by screws. A central hole 13 is opened in the center of the top plate 123. The propeller lifting mechanism 3 is fixed to the surface of the base plate 121 and located between the two vertical plates 122. Its output end can extend upward through the central hole 13 to adjust the height and blade angle of the propeller 4 to be tested, so that it can contact the heads of the three high-precision force measuring units.

[0024] In this embodiment, the high-precision force measuring unit adopts a six-dimensional force sensor, which can measure the force in each direction in the XYZ three-dimensional space and the torque around that direction. Its accuracy level can reach ±0.5%FS (full scale) standard. It contacts the blade through the ball joint at the top and is equipped with a laser tracker, which can accurately capture the deformation after being subjected to force in each direction. Through digital acquisition and automatic processing, the influence of human error and mechanical friction is eliminated, and the measurement accuracy is improved to ±0.1mm.

[0025] This device also includes a data acquisition and processing module, which consists of a 24-bit high-precision data acquisition card and an industrial computer. The two are used for signal acquisition and centroid coordinate calculation, respectively. The sampling frequency can reach up to 10kHz, and it is equipped with dedicated measurement and analysis software.

[0026] like Figure 3-5As shown, in this embodiment, the propeller lifting mechanism 3 includes a housing 34, a servo motor 33, a drive assembly, and a lifting column 31. The lifting column 31 is a threaded column, and a limiting groove 35 is formed on its surface along its length. The two sides of the housing are fixed to the base plate 121. The output shaft axis of the servo motor 33 is located in a horizontal plane parallel to the base plate 121. The drive assembly can output the rotation of the servo motor 33 around the horizontal axis as the vertical lifting motion of the lifting column 31, thereby realizing the precise vertical positioning of the propeller 4 to be measured by the measuring unit 2. The drive assembly includes a worm gear 36 and a worm wheel 37 that meshes with it. The shafts of the two are perpendicular. The worm gear 36 is connected to the output shaft of the servo motor 33 via a flexible coupling 38 and rotates with it. Both ends of the worm wheel 37 are rotatably engaged with the housing 34 via bearings 39. The end of the worm gear 36 away from the servo motor 33 is also rotatably engaged with the housing 34 via bearings 39, thereby enabling the worm wheel 37 to rotate relative to the housing 34 with the worm gear 36. The inner wall of the center hole of the worm wheel 37 is provided with an internal thread that engages with the lifting column 31, and a limit key is provided between the two to engage with the limit groove 35. The engagement of the limit key with the limit groove 35 restricts the rotation of the lifting column 31, so that the lifting column 31 can only move vertically relative to the worm wheel 37.

[0027] Its specific implementation method is as follows: After receiving the control signal, the servo motor 33 drives the worm gear 36 to rotate through the flexible coupling 38. The worm gear 36 meshes with the worm wheel 37 to convert high speed and low torque into low speed and high torque to meet heavy load requirements. The worm wheel 37 and the lifting rod 31 are connected by a thread to convert the rotational motion into the axial linear motion of the lifting rod 31. The lifting rod 31 is restricted from rotation by the keyway and only moves up and down in the vertical direction, thereby realizing the height adjustment of the propeller 4 under test. In addition, after the servo motor 33 stops, the worm gear 36 and the worm wheel 37 self-lock to ensure the stable position of the lifting rod 31.

[0028] like Figure 3 , 6 As shown in Figure 7, in this embodiment, the top of the lifting column 31 is provided with a transition plane 32, and the edge of the transition plane 32 is provided with multiple screw holes. The mounting part of the propeller 4 under test can be connected to the transition plane 32 through the transition flange 5. One end of the transition flange 5 is a flange with screw holes, which can be fixedly connected to the transition plane 32 by bolts. The other end face is provided with a protruding conical opening 51, which can be installed with the mounting part of the propeller 4 under test, increasing the propeller center positioning and adapting to the installation requirements of different types of propellers.

[0029] In this embodiment, the platform support base 11 is a rectangular flat plate with 4 to 6 leveling supports 14 installed at its bottom. These supports are used to adjust the levelness of the surface of the platform support base 11, ensuring that it is in a horizontal plane before measurement and thus ensuring stability during the measurement process.

[0030] In this embodiment, the surface of the top plate 123 is also provided with an annular groove 124 concentric with the central hole 13. The annular groove 124 is provided with three evenly spaced mounting holes 125. The bottom ends of the three high-precision force measuring units are respectively fixed in the mounting holes 125.

[0031] On the other hand, the present invention also provides a high-precision propeller centroid position measurement method based on the above-mentioned device, comprising the following steps: The device was installed and debugged. The support platform assembly 1 was horizontally installed on a stable foundation. The levelness of the support platform assembly 1 was adjusted using an electronic level and leveling support 14 to ensure that its horizontal error was less than 0.01 mm / m. The three high-precision force measuring units were then precisely fixed on the measuring platform. S1: System initial calibration S11: The spatial position coordinates of the three high-precision force measuring units of the measuring component 2 are accurately determined by a coordinate measuring machine and their spatial coordinates are recorded. This process needs to be repeated three times, and the average value is taken as the final calibration result to ensure that the initial position of the high-precision force measuring unit and the propeller lifting mechanism is accurate. S12: Perform zero-point calibration and sensitivity calibration on three high-precision force measuring units, and trace the force value through a standard mass block to ensure measurement accuracy; S13: Force values ​​are calibrated using standard mass blocks to ensure accurate and reliable data acquisition; S2: Specimen Installation and Positioning S21: Install the propeller 4 to be tested 4 at the output end of the propeller lifting mechanism 3 through the adapter flange 5, so that it is located at the center of the support platform assembly 1; S22: The height of the propeller 4 under test is slowly lowered by the propeller lifting mechanism 3, and the position of the three blades of the propeller is adjusted so that they are respectively within the support range of the three high-precision force measuring units, that is, in contact with the preset measurement point on the propeller. S23: Check the contact status between each force measuring unit and the propeller to ensure measurement reliability; S3: Measurement Data Acquisition and Processing S31: After the contact between each blade of the propeller is stable, the output data of all high-precision force measurement units are collected synchronously through the data acquisition card, and the collected data is uploaded to the calculation software and the dedicated analysis software is run for data processing. S32: Record the environmental temperature and humidity parameters that affect the measurement results; S4: Centroid Coordinate Calculation S41: Based on the principle of static equilibrium, the measurement equations are established, where the total gravity equilibrium equation is: F a + F b + F c = G, Among them, a, b, and c are three high-precision force measuring units. A virtual three-dimensional coordinate system is established on the top plane of the support base, and the contact position (X) of the three high-precision force measuring units is accurately measured by a coordinate measuring machine. a Y a ), (X) b Y b ), (X) c Y c G is the total weight of the propeller, F is the total weight of the propeller. a F b F c Readings for each force measuring unit; S42: The least squares method is used to solve the system of equations to obtain the best estimate of the centroid coordinates. After conversion, the final centroid coordinate formula is obtained, including the torque balance equation: F a ·X a + F b ·X b + F c ·X c = G·X c F a ·Y a + F b ·Y b + F c ·Y c = G·Y c , centroid coordinates (X) g Y g ),but X g =(F a ·X a +F b ·X b +F c ·X c ) / (F a + F b + F c ) Y g =(F a ·Y a +F b ·Y b +F c ·Y c ) / (Fa + F b + F c ); S5: Measurement Result Verification and Output S51: By changing the combination of measurement point positions, perform multiple (at least three) repeated measurements and calculate the repeatability error of the measurement results; S52: Cross-comparison verification by changing the measurement orientation; S53: Generate a detailed measurement report, including centroid coordinates, uncertainty analysis, and data quality assessment; S54: Outputs a three-dimensional centroid location map and a measurement data table. The former includes a three-dimensional distribution map of the propeller centroid and a curve showing the change of the centroid position over time.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-precision propeller center-of-mass position measuring device, characterized in that, include: Support platform components, propeller lifting mechanism, and measurement components. The support platform assembly includes a platform support base and a support seat fixed to its surface, and the top of the support seat has a central hole; The propeller lifting mechanism is fixed to the inner side of the support base, and its output end can extend upward along the central hole and be adapted to the mounting part of the propeller to be tested. The measuring component includes three high-precision force measuring units, which are fixed in an equilateral triangle on the same circumference concentric with the central hole on the top of the support base. The propeller under test can be raised and lowered by the propeller lifting mechanism so that the roots of its three blades contact the heads of the three high-precision force measuring units respectively.

2. The high-precision propeller centroid position measuring device according to claim 1, characterized in that, The support base includes a base plate, two vertical plates arranged at intervals, and a top plate. The base plate is fixed to the surface of the platform support base. The bottom ends of the two vertical plates are perpendicularly connected to the base plate. The bottom of the top plate is perpendicularly connected to the top ends of the two vertical plates. The central hole is opened in the center of the top plate. The propeller lifting mechanism is fixed to the surface of the base plate and located between the two vertical plates. Its output end can extend upward through the central hole.

3. The high-precision propeller centroid position measuring device according to claim 2, characterized in that, The propeller lifting mechanism includes a housing, a servo motor, a drive assembly, and a lifting column. The housing is fixed to the base plate, and the drive assembly can output the rotation of the servo motor around the horizontal axis as the lifting motion of the lifting column relative to the support base.

4. The high-precision propeller centroid position measuring device according to claim 3, characterized in that, The lifting column is a threaded column, and a limiting groove is formed on its surface along its length. The drive assembly includes a worm and a worm wheel that meshes with it, with their axes of rotation perpendicular to each other. The worm is connected to the output shaft of the servo motor and rotates with it. The two ends of the worm wheel are rotatably engaged with the housing through bearings, thereby enabling the worm wheel to rotate with the worm. The inner wall of the central hole of the worm wheel is provided with an internal thread that engages with the lifting column, and a limiting key is provided between the two to engage with the limiting groove, so that the lifting column can only move up and down relative to the worm wheel.

5. The high-precision propeller centroid position measuring device according to claim 3, characterized in that, The top of the lifting column is provided with a transition plane, and the edge of the transition plane is provided with multiple screw holes.

6. The high-precision propeller centroid position measuring device according to claim 5, characterized in that, The mounting part of the propeller under test can be connected to the adapter plane through an adapter flange. One end of the adapter flange is a flange with a screw hole, and the other end face is provided with a protruding conical opening.

7. The high-precision propeller centroid position measuring device according to claim 1, characterized in that, The bottom of the platform support base is equipped with 4 to 6 leveling supports for adjusting the levelness of the platform support base surface.

8. The high-precision propeller centroid position measuring device according to claim 2, characterized in that, The top plate has an annular groove concentric with the central hole. The annular groove has three evenly spaced mounting holes, and the bottom ends of the three high-precision force measuring units are respectively fixed in the mounting holes.

9. The high-precision propeller centroid position measuring device according to claim 1, characterized in that, It also includes a data acquisition and processing module, which includes a 24-bit high-precision data acquisition card and an industrial computer, which are used for signal acquisition and centroid coordinate calculation, respectively.

10. A high-precision propeller centroid position measurement method based on the device described in claims 1-9, characterized in that, Includes the following steps: S1: System initial calibration S11: Accurately determine the spatial coordinates of the measuring components to ensure the accurate initial position of the high-precision force measuring unit and the propeller lifting mechanism; S12: Perform zero-point calibration and sensitivity calibration on three high-precision force measuring units, and trace the force value through a standard mass block to ensure measurement accuracy; S13: Force values ​​are calibrated using standard mass blocks to ensure accurate and reliable data acquisition; S2: Specimen Installation and Positioning S21: Install the propeller to be tested at the output end of the propeller lifting mechanism via an adapter flange; S22: Adjust the position of the three propeller blades so that they are respectively within the support range of the three high-precision force measurement units; S23: Check the contact status between each force measuring unit and the propeller to ensure measurement reliability; S3: Measurement Data Acquisition and Processing S31: After the contact between each blade of the propeller is stable, the output data of all high-precision force measurement units are collected synchronously, the collected data is uploaded to the calculation software, and the dedicated analysis software is run for data processing. S32: Record the environmental temperature and humidity parameters that affect the measurement results; S4: Centroid Coordinate Calculation S41: Based on the principle of static equilibrium, the measurement equations are established, where the total gravity equilibrium equation is: F a + F b + F c = G, Among them, a, b, and c are three high-precision force measuring units. A virtual three-dimensional coordinate system is established on the top plane of the support base, and the contact position (X) of the three high-precision force measuring units is accurately measured. a Y a ), (X) b Y b ), (X) c Y c G is the total weight of the propeller, F is the total weight of the propeller. a F b F c Readings for each force measuring unit; S42: The least squares method is used to solve the system of equations to obtain the best estimate of the centroid coordinates. After conversion, the final centroid coordinate formula is obtained, including the torque balance equation: F a ·X a + F b ·X b + F c ·X c = G·X c F a ·Y a + F b ·Y b + F c ·Y c = G·Y c , centroid coordinates (X) g Y g ),but X g =(F a ·X a +F b ·X b +F c ·X c ) / (F a + F b + F c ) Y g =(F a ·Y a +F b ·Y b +F c ·Y c ) / (F a + F b + F c ); S5: Measurement Result Verification and Output S51: Perform multiple repeated measurements and calculate measurement repeatability; S52: Cross-comparison verification by changing the measurement orientation; S53: Generate a detailed measurement report, including centroid coordinates, uncertainty analysis, and data quality assessment; S54: Outputs a 3D centroid location diagram and a measurement data table.

Images