A method for adjusting the load center of a force application device of a mold half balance calibration system

Abstract

The present application belongs to the technical field of wind tunnel test, and discloses a method for adjusting the loading center of a force applying device of a half-model balance calibration system. The method comprises establishing a balance calibration center; comparing the size of the balance to calculate the displacement amount; adjusting the target position of the normal force applying point; and adjusting the target position of the lateral force applying point. The method takes the initial position state of the reference balance at the initial stage of the construction of the half-model balance calibration system as the reference, uses a laser tracker to determine that the loading center of the force applying device coincides with the calibration center of the initial balance, and records the original positions of the force applying points. During subsequent calibration, the size of the balance to be calibrated and the reference balance is iteratively calculated to obtain the target positions of the force applying points, and then the grating ruler and laser interferometer measurement and manual adjustment by the staff are used to adjust the force applying points to the target positions, so that the balance calibration center of the balance to be calibrated coincides with the loading center of the force applying device, and the calibration data accuracy of the balance to be calibrated is ensured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wind tunnel test, and particularly relates to a method for adjusting the loading center of a force applying device of a half-model balance calibration system. BACKGROUND

[0002] The half-model balance calibration system generally adopts a ground axis calibration mode, and the ground axis calibration mode does not reset during calibration loading, and requires that the balance calibration center and the loading center of the force applying device must be strictly consistent, otherwise the force applying devices distributed around will generate additional force and torque due to azimuth error when the load is applied, the additional force and torque acting on the balance to be calibrated will introduce an additional error source, resulting in that the finally fitted balance calibration formula is not accurate enough. Therefore, ensuring that the balance calibration center and the loading center of the force applying device coincide is one of the important works in the half-model balance calibration process.

[0003] At present, the half-model balance calibration system usually deploys one theodolite in each direction perpendicular to the horizontal plane to measure the loading center of the force applying device, and then manually adjusts to ensure that the loading center of the force applying device and the balance calibration center coincide, but the final accuracy of this method depends on the measurement accuracy of the theodolite, and in order to pursue higher measurement accuracy, the most accurate electronic theodolite must be purchased, which is very expensive and does not have cost performance in engineering applications.

[0004] At present, it is urgent to develop a method for adjusting the loading center of the force applying device of the half-model balance calibration system. SUMMARY

[0005] The technical problem to be solved by the application is to provide a method for adjusting the loading center of the force applying device of the half-model balance calibration system to overcome the defects of the prior art.

[0006] The method for adjusting the loading center of the force applying device of the half-model balance calibration system comprises the following steps:

[0007] A. establishing a balance calibration center;

[0008] B. comparing the size of the balance to calculate the displacement;

[0009] C. adjusting the target position of the normal force applying point;

[0010] D. adjusting the target position of the lateral force applying point.

[0011] Further, the A of establishing the balance calibration center comprises the following steps:

[0012] A1. installing a reference balance on the half-model balance calibration system, and installing a loading head on the reference balance;

[0013] A2. Select a robust pile foundation on the support frame of the half-mold balance calibration system, permanently deploy no less than 12 reflective target ball bases, and symmetrically install the reflective target ball bases at the upper left point, lower left point, upper right point, lower right point, front point, and rear point of the reference balance, respectively;

[0014] A3. Install a laser tracker support near the reference balance, fix the laser tracker main machine on the laser tracker support, and adjust the spatial position of the main machine to ensure that the laser tracker main machine can track all the reflective target balls;

[0015] A4. Establish a three-dimensional coordinate network, place reflective target balls on the 12 reflective target ball bases respectively, control the laser tracker main machine to align the reflective target balls in turn, record the coordinate data of each reflective target ball, and use computer software to establish a three-dimensional coordinate network I for the 12 reflective target balls;

[0016] A5. Place a reflective target ball on the reference surface of the loading head, and measure the position data of the reference balance in the three-dimensional coordinate network I according to the established three-dimensional coordinate network I;

[0017] A6. According to the position data of the reference balance in the three-dimensional coordinate network I and the three-dimensional model graph of the reference balance, calculate the position coordinates of the balance calibration center of the reference balance in the three-dimensional coordinate network I;

[0018] A7. Re-establish a three-dimensional coordinate network II with the balance calibration center of the reference balance as the coordinate origin; the coordinate origin of the three-dimensional coordinate network II is the balance calibration center, the X-axis is along the balance axis to the rear, the Y-axis is upward, and the Z-axis is to the left; manually adjust the force points of the force applying device of the half-mold balance calibration system with the coordinate origin as the reference until the force points are symmetrically up and down, left and right, front and back, and then lock the positions of the force points;

[0019] There are a total of 12 force points, of which 8 are normal force points numbered as force point Y1 to force point Y8, and 4 are lateral force points numbered as force point Z1 to force point Z4; force point Y1 is on the negative X-axis, force point Y4 is on the positive X-axis, force point Y1 and force point Y4 are symmetrically front and back, force point Y2 is on the negative Z-axis, force point Y3 is on the positive Z-axis, force point Y2 and force point Y3 are symmetrically left and right, and force point Y1 to force point Y4 realize the application of force and torque in the positive Y direction; force point Y5 to force point Y8 correspond one-to-one to force point Y1 to force point Y4 and are symmetrically up and down, and force point Y5 to force point Y8 realize the application of force and torque in the negative Y direction;

[0020] The force point Z1 is on the positive Y axis, the force point Z2 is on the negative Y axis, the force point Z1 and the force point Z2 are symmetrical up and down, the force point Z1 and the force point Z2 realize the force and torque in the positive Z direction; the force point Z3 and the force point Z4 correspond to the force point Z1 and the force point Z2 respectively, and are symmetrical left and right, the force point Z3 and the force point Z4 realize the force and torque in the negative Z direction;

[0021] A8. Read the grating ruler readings of the 12 force points as initial state values for standby.

[0022] Further, the size of the B contrast balance is calculated to calculate the displacement amount; comprising the following steps:

[0023] B1. Compare the size of the reference balance and the balance to be calibrated to calculate the X-axis displacement amount ΔL1 required for the force applying device of the half-mould balance calibration system to adjust;

[0024] B2. In the same way, calculate the Y-axis displacement amount ΔL2 required for the force applying device of the half-mould balance calibration system to adjust;

[0025] B3. In the same way, calculate the Z-axis displacement amount ΔL3 required for the force applying device of the half-mould balance calibration system to adjust.

[0026] Further, the C adjustment method of the target position of the normal force point comprises the following steps:

[0027] C1. For the normal force point Y1, use the grating ruler to measure the initial position reading L x10 and L z10 of the force point Y1;

[0028] C2. Calculate the target position (L x11 , L z11 ) of the force point Y1, L x11 =L x10 +ΔL1 / 2, L z11 =L z10+ ΔL3 / 2;

[0029] C3. Move the force point Y1 to the target position (L x11 , L z11 );

[0030] C4. Use the laser interferometer to review whether the force point Y1 reaches the target position (L x11 , L z11 ), and manually adjust the force point Y1 until the target position measurement accuracy is less than 1 μm;

[0031] C5. In the same way, move the force point Y2 to the corresponding target position to complete the target position adjustment of the normal force point.

[0032] Further, the target position of the lateral force application point of D is adjusted by the following steps:

[0033] D1. For the lateral force application point Z1, the initial position reading L of the force application point Z1 is measured by the grating ruler x90 and L z90 ;

[0034] D2. The target position (L x91 , L z91 ) of the force application point Z1 is calculated, L x91 =L x90 +ΔL1 / 2, L z91 =L z90 +ΔL3 / 2;

[0035] D3. The force application point Z1 is moved to the target position (L x91 , L z91 );

[0036] D4. The laser interferometer is used to check whether the force application point Z1 reaches the target position (L x91 , L z91 ). The force application point Z1 is manually adjusted by the operator until the measurement accuracy of the target position is less than 1 μm;

[0037] D5. The initial position Ly90 of the force application point Z1 in the normal direction is measured by the laser interferometer;

[0038] D6. The target position (Lx11, Lz11) of the force application point Y1 is measured by the laser interferometer;

[0039] D7. The Y-axis target position Ly91 of the force application point Z1 is calculated, Ly91=Ly90+ΔL2 / 2;

[0040] D8. The force application point Z1 is adjusted to the Y-axis target position to ensure that the force application point Z1 and the calibration center of the balance to be calibrated are located at the same height;

[0041] D9. In the same way, the force application points Z2~Z4 are moved to the corresponding target positions to complete the adjustment of the target positions of the lateral force application points.

[0042] The method for adjusting the loading center of the force applying device of the half-mould balance calibration system of the application takes the initial position state of the reference balance at the initial stage of the construction of the half-mould balance calibration system as the reference, determines the coincidence of the loading center of the force applying device and the calibration center of the initial balance by using a laser tracker, and records the original positions of each force applying point; during the subsequent calibration, the size of the balance to be calibrated and the reference balance is iteratively calculated to obtain the target positions of each force applying point, and then the target positions of each force applying point are adjusted to the target positions by using the grating ruler and laser interferometer measurement and manual adjustment of the staff, so that the calibration center of the balance to be calibrated coincides with the loading center of the force applying device, thereby ensuring the accuracy of the calibration data of the balance to be calibrated.

[0043] The method for adjusting the loading center of the force applying device of the half-mould balance calibration system of the application has high accuracy and cost performance, and has engineering practical value. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 It is a layout schematic diagram of the reflecting target ball base and the force applying device in the half-mould balance calibration system.

[0045] Figure 2 It is a force applying coordinate system schematic diagram of the half-mould balance calibration system.

[0046] Figure 3 It is a relative position schematic diagram of the calibration center of the reference balance and the calibration center of the balance to be calibrated.

[0047] In the figure, 11. positive Y direction force applying device; 12. positive Z direction force applying device; 13. negative Y direction force applying device; 14. negative Z direction force applying device; 15. reference balance; 16. loading head; 17. left upper point; 18. left lower point; 19. right upper point; 20. right lower point; 21. front point. DETAILED DESCRIPTION

[0048] The application will be described in detail below in combination with the drawings and examples.

[0049] Example: The method for adjusting the loading center of the force applying device of the half-mould balance calibration system of the embodiment comprises the following steps:

[0050] A. establishing the balance calibration center;

[0051] B. comparing the size of the balance to calculate the displacement;

[0052] C. adjusting the target position of the normal force applying point;

[0053] D. adjusting the target position of the lateral force applying point.

[0054] Further, the A of establishing the balance calibration center comprises the following steps:

[0055] A1. As shown in Figure 1 The reference balance 15 is installed on the upper installation reference balance 15 of the half-mold balance calibration system, and the loading head 16 is installed on the reference balance 15;

[0056] A2. Select a thick pile foundation on the support frame of the half-mold balance calibration system, and permanently deploy no less than 12 reflective target ball bases. The 12 reflective target ball bases are symmetrically installed at the left upper point 17, the left lower point 18, the right upper point 19, the right lower point 20, the front point 21, and the rear point of the reference balance 15, respectively.

[0057] A3. Install a laser tracker support near the reference balance 15, fix a laser tracker main machine on the laser tracker support, and adjust the spatial position of the main machine to ensure that the laser tracker main machine can track all the reflective target balls.

[0058] A4. Establish a three-dimensional coordinate network. Place a reflective target ball on each of the 12 reflective target ball bases, control the laser tracker main machine to align the reflective target balls in turn, record the coordinate data of each reflective target ball, and use computer software to establish a three-dimensional coordinate network I for the 12 reflective target balls.

[0059] A5. Place a reflective target ball on the reference surface of the loading head 16, and measure the position data of the reference balance 15 in the three-dimensional coordinate network I according to the established three-dimensional coordinate network I.

[0060] A6. According to the position data of the reference balance 15 in the three-dimensional coordinate network I and the three-dimensional model diagram of the reference balance 15, the position coordinates of the balance calibration center of the reference balance 15 in the three-dimensional coordinate network I are calculated.

[0061] A7. Take the balance calibration center of the reference balance 15 as the coordinate origin to re-establish a three-dimensional coordinate network II. The coordinate origin of the three-dimensional coordinate network II is the balance calibration center, the X-axis is along the balance axis to the rear, the Y-axis is upward, and the Z-axis is to the left. Take the coordinate origin as the reference, manually adjust the force points of the force applying device of the half-mold balance calibration system until the force points are symmetrically up and down, left and right, and then lock the positions of the force points.

[0062] As shown in Figure 2 There are 12 force points in total, of which 8 are normal force points numbered as force point Y1 to force point Y8, and 4 are lateral force points numbered as force point Z1 to force point Z4. Figure 1 The positive Y-direction force applying device 11 and the negative Y-direction force applying device 13 are shown in detail. Figure 1The positive Z-direction force applying device 12 and the negative Z-direction force applying device 14; the force applying point Y1 is on the negative X-axis, the force applying point Y4 is on the positive X-axis, the force applying point Y1 and the force applying point Y4 are symmetric front and back, the force applying point Y2 is on the negative Z-axis, the force applying point Y3 is on the positive Z-axis, the force applying point Y2 and the force applying point Y3 are symmetric left and right, the force applying point Y1-Y4 can apply force and torque in the positive Y direction; the force applying point Y5-Y8 correspond to the force applying point Y1-Y4 respectively, symmetric up and down, the force applying point Y5-Y8 can apply force and torque in the negative Y direction;

[0063] The force applying point Z1 is on the positive Y-axis, the force applying point Z2 is on the negative Y-axis, the force applying point Z1 and the force applying point Z2 are symmetric up and down, the force applying point Z1 and the force applying point Z2 can apply force and torque in the positive Z direction; the force applying point Z3 and the force applying point Z4 correspond to the force applying point Z1 and the force applying point Z2 respectively, symmetric left and right, the force applying point Z3 and the force applying point Z4 can apply force and torque in the negative Z direction;

[0064] A8. Read the grating ruler readings of the 12 force applying points as initial state values for standby.

[0065] Further, the size of the contrast balance of B is calculated to calculate the displacement amount; comprising the following steps:

[0066] B1. Comparing the size of the reference balance 15 with the size of the balance to be calibrated, calculating the X-axis displacement amount ΔL1 that the force applying device of the half-mould balance calibration system needs to adjust, the X-axis displacement amount ΔL1 is shown in Figure 3 ;

[0067] B2. Using the same method, calculating the Y-axis displacement amount ΔL2 that the force applying device of the half-mould balance calibration system needs to adjust;

[0068] B3. Using the same method, calculating the Z-axis displacement amount ΔL3 that the force applying device of the half-mould balance calibration system needs to adjust.

[0069] Further, the adjustment method of the target position of the normal force applying point of C comprises the following steps:

[0070] C1. For the normal force applying point Y1, the initial position readings L x10 and L z10 of the force applying point Y1 are measured by the grating ruler;

[0071] C2. The target position (L x11 , L z11 ) of the force applying point Y1 is calculated, L x11 =L x10 +ΔL1 / 2, L z11 =L z10+ ΔL3 / 2;

[0072] C3. The force applying point Y1 is moved to the target position (Lx11 , L z11 );

[0073] C4. Use the laser interferometer to review whether the force point Y1 reaches the target position (L x11 , L z11 ), and manually adjust the force point Y1 by the staff until the target position measurement accuracy is less than 1 μm; the measurement accuracy of the laser interferometer is less than 0.1 μm, and the measurement accuracy of the grating ruler is less than 3 μm; the grating ruler is convenient to use, the measurement accuracy of the laser interferometer is high, and the combination of the two can improve the measurement efficiency while improving the measurement accuracy;

[0074] C5. In the same way, move the force points Y2-Y8 to the corresponding target positions to complete the normal force point target position adjustment.

[0075] Further, the adjustment of the target position of the lateral force point of D includes the following steps:

[0076] D1. For the lateral force point Z1, use the grating ruler to measure the initial position reading L x90 and L z90 of the force point Z1;

[0077] D2. Calculate the target position (L x91 , L z91 ) of the force point Z1, L x91 =L x90 +ΔL1 / 2, L z91 =L z90 +ΔL3 / 2;

[0078] D3. Move the force point Z1 to the target position (L x91 , L z91 );

[0079] D4. Use the laser interferometer to review whether the force point Z1 reaches the target position (L x91 , L z91 ), and manually adjust the force point Z1 by the staff until the target position measurement accuracy is less than 1 μm;

[0080] D5. Use the laser interferometer to measure the initial position Ly90 of the force point Z1 in the normal direction;

[0081] D6. Use the laser interferometer to review the target position (Lx11, Lz11) of the force point Y1;

[0082] D7. Calculate the Y-axis target position Ly91 of the force point Z1 Ly91=Ly90+ΔL2 / 2;

[0083] D8. Adjust the force point Z1 to the Y axis target position to ensure that the force point Z1 and the calibration center of the balance to be calibrated are at the same height;

[0084] D9. In the same way, move the force point Z2 to the force point Z4 to the corresponding target position to complete the lateral force point target position adjustment.

[0085] Although embodiments of the present application have been disclosed in connection with the illustrative embodiments set forth above, it should be understood that there can be other embodiments which fall within the principles of the application, and that many changes can be made to the details of the above-described embodiments without departing from the scope of the application. Accordingly, the scope of the present application should not be limited to the above-described embodiments and drawings.

Claims

1. A method for adjusting the load center of a force application device of a mold half balance calibration system, characterized by, Comprising the following steps: A. Establishing a balance calibration center; Comprising the following steps: A1. Installing a reference balance (15) on the upper half of the balance calibration system, and installing a loading head (16) on the reference balance (15); A2. Selecting a robust pile foundation on the support frame of the half-mold balance calibration system, and permanently deploying 12 reflective target ball bases symmetrically installed at the upper left point (17), the lower left point (18), the upper right point (19), the lower right point (20), the front point (21), and the rear point of the reference balance (15); A3. Installing a laser tracker support near the reference balance (15), fixing a laser tracker main machine on the laser tracker support, and adjusting the spatial position of the laser tracker main machine to ensure that it can track all the reflective target balls; A4. Establishing a three-dimensional coordinate network, placing reflective target balls on the 12 reflective target ball bases, controlling the laser tracker main machine to sequentially aim at the reflective target balls, recording the coordinate data of each reflective target ball, and using computer software to establish a three-dimensional coordinate network I for the 12 reflective target balls; A5. Placing a reflective target ball on the reference surface of the loading head (16), and measuring the position data of the reference balance (15) in the three-dimensional coordinate network I according to the established three-dimensional coordinate network I; A6. Calculating the position coordinates of the balance calibration center of the reference balance (15) in the three-dimensional coordinate network I according to the position data of the reference balance (15) in the three-dimensional coordinate network I and the three-dimensional numerical model of the reference balance (15); A7. Re-establishing a three-dimensional coordinate network II with the balance calibration center of the reference balance (15) as the coordinate origin; the coordinate origin of the three-dimensional coordinate network II is the balance calibration center, the X-axis is along the balance axis to the rear, the Y-axis is upward, and the Z-axis is to the left; manually adjusting the force points of the force applying device of the half-mold balance calibration system with the coordinate origin as the reference until each force point is symmetrically arranged in the up-down, left-right, front-rear directions, and then locking the positions of each force point; There are a total of 12 force points, of which 8 are normal force points numbered as force point Y1 to force point Y8, and 4 are lateral force points numbered as force point Z1 to force point Z4; force point Y1 is on the negative X-axis, force point Y4 is on the positive X-axis, force point Y1 and force point Y4 are symmetrically arranged in the front-rear direction, force point Y2 is on the negative Z-axis, force point Y3 is on the positive Z-axis, force point Y2 and force point Y3 are symmetrically arranged in the left-right direction, and force point Y1 to force point Y4 can apply force and torque in the positive Y direction; force point Y5 to force point Y8 correspond to force point Y1 to force point Y4 one by one and are symmetrically arranged in the up-down direction, and force point Y5 to force point Y8 can apply force and torque in the negative Y direction; Force point Z1 is on the positive Y-axis, force point Z2 is on the negative Y-axis, force point Z1 and force point Z2 are symmetrically arranged in the up-down direction, and force point Z1 and force point Z2 can apply force and torque in the positive Z direction; force point Z3 and force point Z4 correspond to force point Z1 and force point Z2 one by one and are symmetrically arranged in the left-right direction, and force point Z3 and force point Z4 can apply force and torque in the negative Z direction; A8. Read the grating ruler readings of 12 force points as initial state values for standby; B. Calculate the displacement amount by comparing the sizes of the scales; C. Adjust the target positions of the normal force points; D. Adjust the target positions of the lateral force points.

2. The method for adjusting the load center of a force application device of a half die balance calibration system of claim 1, wherein, The B of calculating the displacement amount by comparing the sizes of the scales comprises the following steps: B1. Calculate the X-axis displacement amount ΔL1 that the force applying device of the half-mould scale calibration system needs to adjust by comparing the sizes of the reference scale (15) and the scale to be calibrated; B2. Calculate the Y-axis displacement amount ΔL2 that the force applying device of the half-mould scale calibration system needs to adjust by using the same method; B3. Calculate the Z-axis displacement amount ΔL3 that the force applying device of the half-mould scale calibration system needs to adjust by using the same method.

3. The method for adjusting the load center of a force application device of a half die balance calibration system of claim 2, wherein, The C of adjusting the target positions of the normal force points comprises the following steps: C1. For the normal force application point Y1, the initial position reading L of the force application point Y1 is measured using the grating ruler x10 and L z10 ; C2. Calculate the target position (L) of the force application point Y1. x11 L z11 ), L x11 =L x10 +ΔL1 / 2, L z11 =L z10+ ΔL3 / 2; C3. Move the application point Y1 to the target position (L x11 , L z11 ); C4. Check whether the force point Y1 reaches the target position (L x11 , L z11 ) using a laser interferometer, and manually adjust the force point Y1 by the staff until the measurement accuracy of the target position is less than 1 μm; C5. Move the force points Y2-Y8 to the corresponding target positions by using the same method, and complete the adjustment of the target positions of the normal force points.

4. The method for adjusting the load center of a force application device of a half die balance calibration system of claim 3, wherein, The D of adjusting the target positions of the lateral force points comprises the following steps: D1. For the lateral force application point Z1, the initial position reading L of the force application point Z1 is measured with the grating scale x90 and L z90 ; D2. Calculate the target position (L x91 , L z91 ) of the force application point Z1, L x91 = L x90 + ΔL1 / 2, L z91 = L z90 + ΔL3 / 2; D3. Move the point of application of force Z1 to the target position (L x91 , L z91 ) D4. Check whether the force point Z1 reaches the target position (L x91 , L z91 ) using a laser interferometer, and manually adjust the force point Z1 by the staff until the target position measurement accuracy is less than 1 μm; D5. Measure the initial position Ly90 of the force point Z1 in the normal direction by using the laser interferometer; D6. Review the measurement of the target position (Lx11, Lz11) of the force point Y1 by using the laser interferometer; D7. Calculate the Y-axis target position Ly91 of the force point Z1, Ly91 = Ly90 + ΔL2 / 2; D8. Adjust the force point Z1 to the Y-axis target position to ensure that the force point Z1 and the calibration center of the scale to be calibrated are located at the same horizontal height; D9. Move the force points Z2-Z4 to the corresponding target positions by using the same method, and complete the adjustment of the target positions of the lateral force points.

Images