Continuous wind tunnel balance calibration data processing method

Abstract

The invention belongs to the technical field of multi-component aerodynamic load measurement sensors, and discloses a continuous wind tunnel balance calibration data processing method, which comprises the steps of configuring calibration parameters; carrying out continuous wind tunnel balance ground calibration; carrying out ground calibration data processing; and screening a working matrix set, and selecting a continuous wind tunnel balance working matrix and an alternative matrix. According to the method, multiple bridge circuits are recombined to form a plurality of calibration data combinations according to the multi-bridge circuit characteristic of the continuous wind tunnel balance and an existing balance ground calibration system, data processing is performed according to a unit calibration method or a multivariate calibration method to obtain a working matrix set, error values of working matrixes are calculated according to test loads, and the continuous wind tunnel balance is calibrated according to the error values. And screening out a working matrix with the minimum error value as a continuous wind tunnel balance working matrix, and determining an alternative matrix. According to the continuous wind tunnel balance calibration data processing method, continuous wind tunnel balance calibration is achieved, a good technical effect is achieved, and the method has engineering practical value.

Description

Technical Field

[0001] The present invention belongs to the technical field of multi-component aerodynamic load measurement sensors, and particularly relates to a method for processing calibration data of a continuous wind tunnel balance. Background Art

[0002] A wind tunnel balance is a multi-dimensional force sensor. The aerodynamic force components measured by the wind tunnel balance are: drag X, lift Y, and side force Z; the moment components are: roll moment Mx, yaw moment My, and pitch moment Mz. Generally, the six components of the wind tunnel balance correspond to six Wheatstone full bridges. Each force and moment corresponds to a Wheatstone full bridge. The Wheatstone full bridge is composed of 4 identical strain gauges connected in series in pairs and then in parallel, and the Wheatstone full bridge is excited by a constant voltage. During the blowing process of the wind tunnel test, the Wheatstone full bridge senses the load and generates a weak deformation. The weak deformation changes the resistance value of the strain gauges of the Wheatstone full bridge, thereby generating a voltage change value △U. The working matrix of the balance obtained through the ground calibration of the balance can calculate the aerodynamic load received by the balance.

[0003] The ground calibration of the balance, also known as static calibration, simulates the stress state of the balance during the wind tunnel test according to the established coordinate axis system, applies a static load to it, and obtains the working matrix of the output voltage signal of each component of the balance and the calibration load for use when calculating the aerodynamic load in the wind tunnel test. The calibration method can be divided into the unit calibration method and the multi-element calibration method according to the loading method. The unit calibration method refers to independently loading each component of the balance, and the other components are zero or constant values at this time. The corresponding data processing method is generally the least squares method. The multi-element calibration method refers to simultaneously loading the combined values formed by each component of the balance according to a certain rule, and the corresponding data processing method is generally the multi-element linear regression algorithm.

[0004] Compared with the blowdown wind tunnel, the continuous wind tunnel has the advantages of stable air flow, long running time, wide range of test conditions, and high test efficiency. However, compared with the running time of about 1 minute for the blowdown wind tunnel once, the continuous wind tunnel runs for a long time in hours after startup, which puts higher requirements on its core measurement equipment - the wind tunnel balance. During the long-term operation of the continuous wind tunnel, once a certain bridge circuit in the wind tunnel balance is damaged, the operation must be stopped, resulting in losses of more than 100,000 yuan. Therefore, the continuous wind tunnel puts forward the requirement for a spare bridge circuit in the development of the wind tunnel balance.

[0005] Therefore, in order to meet the high requirements of the continuous wind tunnel for balance measurement, it is necessary to design and manufacture a continuous wind tunnel balance. The continuous wind tunnel balance has a redundant design for the six components, that is, each component is provided with a main and a spare Wheatstone full bridge. If a certain Wheatstone full bridge is damaged during the blowing process of the continuous wind tunnel test, the corresponding spare Wheatstone full bridge can continue to measure to ensure the high robustness of the measurement of the continuous wind tunnel balance.

[0006] At present, there is an urgent need to develop a continuous wind tunnel balance calibration data processing method. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a continuous wind tunnel balance calibration data processing method to overcome the defects of the prior art.

[0008] The continuous wind tunnel balance calibration data processing method of the present invention includes the following steps: S10. Configure calibration parameters; S20. Perform ground calibration; S30. Perform ground calibration data processing; S40. Screen the working matrix set and select the continuous wind tunnel balance working matrix and alternative matrix.

[0009] Further, the configuration of calibration parameters in S10 includes the following steps: S11. Fill in the calibration loads according to the design loads of the continuous wind tunnel balance, and each calibration load is 90% - 110% of the designed range of the corresponding component; S12. Perform calibration settings on the balance ground calibration system, including moment arm, loading step, and loading tool; S13. Set the bridge circuit information of the wind tunnel balance, compile the load group, determine the unit items, cross items, and multi - item terms, and determine the corresponding inspection loads.

[0010] Further, the performance of ground calibration in S20 includes the following steps: [[ID=3၁]]S21. Load, reset, and collect and record the corresponding original calibration data according to the load group; S22. Load the unit items and cross items using the unit calibration method; load the multi - item terms using the multi - calibration method; S23. Load the inspection load.

[0011] Further, the performance of ground calibration data processing in S30 includes the following steps: S31. Perform six - component combinations in the order of drag X, lift Y, side force Z, roll moment Mx, yaw moment My, and pitch moment Mz. For drag X, the corresponding measurement bridge circuits are M11 and M12. Use M11, M12, and M11 + M12 as the calibration data for drag X respectively to perform ground calibration data processing. Similarly, lift Y, side force Z, roll moment Mx, yaw moment My, and pitch moment Mz each have corresponding three options. There are 3×3×3×3×3×3 = 3 6 = 729 combinations for the 6 components of the continuous wind tunnel balance; The unit calibration method uses the least squares method for data processing, and the multi - variable calibration method uses the multi - variable linear regression algorithm for data processing to fit out the working matrix set of the continuous wind tunnel balance. The working matrix set includes 729 working matrices. S33. Substitute the 729 working matrices in the working matrix set into the test load respectively to obtain 729 corresponding error values, and each error value is characterized by the standard deviation.

[0012] Further, the screening of the working matrix set in S40 includes the following steps: S41. Screen out the working matrix with the smallest error value as the working matrix of the continuous wind tunnel balance. S42. Select alternative matrices. The Wheatstone full - bridges corresponding to the working matrices with the smallest error values of the drag X, lift Y, side force Z, roll moment Mx, yaw moment My, and pitch moment Mz are respectively named M1 - M6. If the Wheatstone full - bridge of one component in M1 - M6 is damaged, then enable the corresponding standby bridge circuit. The working matrix of the standby bridge circuit is the working matrix with the smallest error value among the remaining 5 components of the 3 5 = 243 working matrices, and calculate the aerodynamic load of the damaged component through the standby bridge circuit.

[0013] According to the multi - bridge - circuit characteristics of the continuous wind tunnel balance, the calibration data processing method of the continuous wind tunnel balance of the present invention recombines the multi - bridge circuits based on the existing balance ground calibration system to form multiple calibration data combinations, performs data processing according to the unit calibration method or the multi - variable calibration method to obtain the working matrix set, then calculates the error values of each working matrix according to the test load, screens out the working matrix with the smallest error value as the working matrix of the continuous wind tunnel balance, and determines the alternative matrices.

[0014] The calibration data processing method of the continuous wind tunnel balance of the present invention improves the quality of wind tunnel test data. Based on the existing balance ground calibration system hardware, there is no need to add any supporting facilities or any calibration links; based on the existing balance ground calibration system software, screen out the working matrix with the smallest error value among the 729 working matrices of 6 components as the working matrix of the continuous wind tunnel balance, and then screen out the working matrix with the smallest error value among the 243 working matrices of the remaining 5 components as the standby bridge circuit, which improves the balance calibration accuracy and the quality of wind tunnel test data.

[0015] The continuous wind tunnel balance calibration data processing method of the present invention improves the efficiency of wind tunnel tests. For continuous wind tunnels, especially large-scale continuous wind tunnels, the test preparation cycle is very long. Once a failure such as damage to the balance bridge circuit occurs during the test, resulting in the interruption of the test, it takes at least dozens of hours to resume the test after the problem is solved. If the continuous wind tunnel balance calibration data processing method of the present invention is adopted, even if one or several Wheatstone full bridges in the continuous wind tunnel balance fail, it is still possible to select the calculation matrix after combining the normal bridge circuits without interrupting the test, thus improving the efficiency of continuous wind tunnel tests and having engineering practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1a FIG. is a top view of the Wheatstone full bridge paste positions for the Y and Mz elements of a continuous wind tunnel balance; Figure 1b FIG. is a front view of the Wheatstone full bridge paste positions for the X, Z, Mx, and My elements of a continuous wind tunnel balance; Figure 2a FIG. is a schematic diagram of the paste positions of Wheatstone full bridge strain gauges (partial front view); Figure 2b FIG. is a schematic diagram of the Wheatstone full bridge measurement principle; Figure 3a FIG. is a schematic diagram of the Wheatstone full bridge paste positions of a continuous wind tunnel balance (front view); Figure 3b FIG. is a schematic diagram of the Wheatstone full bridge paste positions of a continuous wind tunnel balance (top view); Figure 3c FIG. is a schematic diagram of the strain gauge connections of the Wheatstone full bridge of a continuous wind tunnel balance; Figure 4a FIG. is a schematic diagram of the recombination of the Wheatstone full bridge of a continuous wind tunnel balance (overall view); Figure 4b FIG. is a schematic diagram of the recombination of the Wheatstone full bridge of a continuous wind tunnel balance (Part I); Figure 4c FIG. is a schematic diagram of the recombination of the Wheatstone full bridge of a continuous wind tunnel balance (Part II); Figure 5 FIG. is a ground calibration flow chart of a continuous wind tunnel balance.

[0017] In the figures, 1 to 48 are strain gauge numbers. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The present invention will be described in detail below with reference to the drawings and embodiments.

[0019] Embodiment: The paste positions of the Wheatstone full bridges of the continuous wind tunnel balance in this embodiment and the corresponding balance coordinate system are shown in Figure 1a 、 Figure 1b。The Wheatstone full bridge is shown in Figure 2a 、 Figure 2b , where the Wheatstone full bridge uses four identical strain gauges, which are connected in series in pairs and then in parallel. R1, R2, R3, and R4 are the resistance values of the bridge arms, U is the bridge excitation voltage, and ΔU is the output voltage. The pasting positions of the Wheatstone full bridge of the continuous wind tunnel balance are shown in Figure 3a 、 Figure 3b , and the corresponding schematic diagram of the strain gauge connection is shown in Figure 3c 。

[0020] As Figure 5 shown, the method for processing calibration data of the continuous wind tunnel balance in this embodiment includes the following steps: S10. Configure calibration parameters; S20. Perform ground calibration; S30. Process the ground calibration data; S40. Screen the working matrix set and select the working matrix and alternative matrix of the continuous wind tunnel balance.

[0021] Further, the configuration of calibration parameters in S10 includes the following steps: S11. Fill in the calibration loads according to the design loads of the continuous wind tunnel balance, and each calibration load is 90% - 110% of the designed range of the corresponding component; S12. Perform calibration settings for the balance ground calibration system, including moment arm, loading step, and loading appliance; S13. Set the bridge circuit information of the wind tunnel balance, compile the load group, determine the unit items, cross items, and multi - variable items, and determine the corresponding inspection loads.

[0022] Further, the performance of ground calibration in S20 includes the following steps: S21. Load, reset, and collect and record the corresponding original calibration data according to the load group; S22. Use the unit calibration method to load the unit items and cross items; use the multi - variable calibration method to load the multi - variable items; S23. Load the inspection loads.

[0023] Further, the processing of ground calibration data in S30 includes the following steps: S31. Perform six-component combinations in the order of drag X, lift Y, side force Z, rolling moment Mx, yaw moment My, and pitch moment Mz. For the drag X, there are two corresponding measurement bridge circuits, M11 and M12. Treat M11, M12, and M11 + M12 as calibration data for drag X respectively to process the ground calibration data. Similarly, lift Y, side force Z, rolling moment Mx, yaw moment My, and pitch moment Mz each have three corresponding options. There are a total of 3×3×3×3×3×3 = 3 6 = 729 combinations for the 6 components of the continuous wind tunnel balance. The combination method is shown in Figures 4a to 4c ; S32. The unit calibration method uses the least squares method for data processing, and the multi - calibration method uses the multiple linear regression algorithm for data processing to fit out the working matrix set of the continuous wind tunnel balance. The working matrix set includes 729 working matrices. Some of the working matrices are shown in Table 1; S33. Substitute the 729 working matrices in the working matrix set into the test load respectively to obtain 729 corresponding error values. Each error value is characterized by the standard deviation.

[0024] Furthermore, the screening of the working matrix set in S40 includes the following steps: S41. Screen out the working matrix with the smallest error value as the working matrix of the continuous wind tunnel balance; S42. Select alternative matrices; Name the Wheatstone full bridges corresponding to the working matrices with the smallest error values of drag X, lift Y, side force Z, rolling moment Mx, yaw moment My, and pitch moment Mz as M1 - M6 respectively. If one of the Wheatstone full bridges of a component in M1 - M6 is damaged, then enable the corresponding spare bridge circuit. The working matrix of the spare bridge circuit is the working matrix with the smallest error value among the remaining 5 components' 3 5 = 243 working matrices to calculate the aerodynamic load of the damaged component through the spare bridge circuit. The working matrices of the spare bridge circuit are shown in Table 2.

[0025] Table 1 Working Matrices of the Continuous Wind Tunnel Balance (Partial)

[0026] Table 2 Spare Bridge Circuits of the Working Matrices

[0027] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. For those skilled in the art, without departing from the principles of the present invention, all features disclosed in the present invention, or steps in all methods or processes disclosed, except for mutually exclusive features and / or steps, can be combined in any way. The present invention is not limited to specific details and the illustrated examples herein.

Claims

1. A method for processing calibration data of a continuous wind tunnel balance, characterized in that, Including the following steps: S10. Configure calibration parameters; S20. Conduct ground calibration; S30. Process ground calibration data; S40. Screen the working matrix set, and select the working matrix and alternative matrix of the continuous wind tunnel balance.

2. The continuous wind tunnel balance calibration data processing method according to claim 1, wherein The configuration of calibration parameters in S10 includes the following steps: S11. According to the design load of the continuous wind tunnel balance, fill in the calibration load, and each calibration load is 90% - 110% of the designed range of the corresponding component; S12. Conduct calibration settings for the ground calibration system of the balance, including moment arm, loading step, and loading device; S13. Set the bridge circuit information of the wind tunnel balance, compile the load group, determine the unit term, cross term, and multi - variable term, and determine the corresponding test load.

3. The continuous wind tunnel balance calibration data processing method according to claim 2, characterized in that, The conduct of ground calibration in S20 includes the following steps: S21. Load, reset, and collect and record the corresponding original calibration data according to the load group; S22. Use the unit calibration method to load the unit term and cross term; use the multi - variable calibration method to load the multi - variable term; S23. Load the test load.

4. The continuous wind tunnel balance calibration data processing method according to claim 3, wherein The process of ground calibration data in S30 includes the following steps: S31. Perform six-component combinations in the order of drag X, lift Y, side force Z, rolling moment Mx, yaw moment My, and pitch moment Mz. For the drag X, there are two corresponding measuring bridge circuits, M11 and M12. Treat the three options of M11, M12, and M11 + M12 as the calibration data for drag X respectively to process the ground calibration data. Similarly, each of the lift Y, side force Z, rolling moment Mx, yaw moment My, and pitch moment Mz has three corresponding options. There are a total of 3×3×3×3×3×3 = 3 6 = 729 combinations for the 6 components of the continuous wind tunnel balance; S32. Use the least - squares method for data processing in the unit calibration method, and use the multi - variable linear regression algorithm for data processing in the multi - variable calibration method to fit out the working matrix set of the continuous wind tunnel balance, and the working matrix set includes 729 working matrices; S33. Substitute the 729 working matrices in the working matrix set into the test load respectively to obtain 729 corresponding error values, and each error value is characterized by the standard deviation.

5. The continuous wind tunnel balance calibration data processing method according to claim 4, wherein The screening of the working matrix set in S40 includes the following steps: S41. Screen out the working matrix with the smallest error value as the working matrix of the continuous wind tunnel balance; S42. Select the alternative matrix; The Wheatstone full bridges corresponding to the working matrices with the smallest error values for the drag X, lift Y, side force Z, roll moment Mx, yaw moment My, and pitch moment Mz are respectively named M1 to M6. If the Wheatstone full bridge of one component among M1 to M6 is damaged, then the corresponding standby bridge circuit is enabled. The working matrix of the standby bridge circuit is the one with the smallest error value among the remaining 5 components other than the damaged component, and there are 3 5 = 243 working matrices. Calculate the aerodynamic load of the damaged component through the standby bridge circuit.

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