Device and method for calibrating inclination angle of thrust measurement balance
By setting up a calibration device on the thrust measurement balance, zero point calibration and sensitivity coefficient calculations are performed, the problem of the initial zero point change under the inclination angle cannot be effectively calibrated by traditional methods, achieving higher measurement accuracy and reliability.
Patent Information
- Application Number
- CN202411886708.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-02-14
AI Technical Summary
The traditional thrust measurement balance calibration method mainly targets vertical or horizontal states, and cannot effectively calibrate the initial zero point change when used at an inclination angle, resulting in the accuracy and reliability of the measurement results being affected.
By determining the inclination angle of the thrust measurement balance, setting up a calibration device, and performing zero point calibration without external force, recording the initial zero point value. Then, a known force is applied, the output value is recorded, the sensitivity coefficients in each direction are calculated, and the calibration measured value is obtained based on the sensitivity coefficient and the initial zero point value.
Eliminates the initial zero point change caused by tilt use, improves measurement accuracy and ensures the accuracy and reliability of thrust measurement at tilt angles.
Smart Images
Figure CN119437542A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of thrust measurement, and in particular to a device and method for calibrating the tilt angle of a thrust measurement balance. Background Art
[0002] In high-precision measurement fields such as aircraft engine testing and automobile collision experiments, the thrust measurement balance is a key measurement device, and its accuracy and reliability are of vital importance. Tests in these fields often need to be carried out under complex environmental conditions, including the need for the thrust measurement balance to be used in a non-vertical state, such as at an inclined angle. However, most traditional thrust measurement balance calibration methods are designed and implemented only for vertical or horizontal states, and lack effective means and methods for calibration in an inclined state. This situation leads to the initial zero point being offset when the thrust measurement balance is used at an inclined angle due to the change in the direction of the force-bearing surface, which seriously affects the accuracy of the measurement results. In aircraft engine testing, accurate measurement of thrust is of great significance for evaluating engine performance, optimizing design, and ensuring safe operation. The thrust generated by the engine is a vector in three-dimensional space, and its magnitude and direction may change with changes in operating conditions. In order to accurately measure these thrusts, the thrust measurement balance needs to be able to maintain high precision at various angles and positions. However, when the balance is in a tilted state, the initial zero point will shift due to the influence of the gravity component and the slight deformation of the internal mechanical structure of the balance. If this shift is not calibrated and corrected, it will directly lead to an increase in the error of the measurement result, and may even mislead engine performance evaluation and optimization decisions. Similarly, in car collision tests, accurate measurement of thrust is also crucial; collision tests are designed to evaluate the safety performance of cars, including the crashworthiness of the car body structure, the effectiveness of airbags, and the performance of passenger protection systems. In these tests, cars are subject to impact forces from different directions and magnitudes, and thrust measurement balances are key equipment for measuring these impact forces. However, since collision tests often involve complex dynamic processes and impact forces at multiple angles, traditional calibration methods in vertical or horizontal states can no longer meet experimental requirements. If the thrust measurement balance is used in an inclined state without being calibrated, the accuracy of the measurement results will be seriously affected, which in turn affects the accurate evaluation of the safety performance of the car. However, traditional calibration methods often ignore the existence of these factors or fail to effectively compensate and correct them; this results in the accuracy and reliability of the measurement results cannot be guaranteed when using a thrust measurement balance at an inclined angle; In summary, the problem of initial zero point change faced by a thrust measuring balance when used at an inclined angle needs to be solved urgently; therefore, a thrust measuring balance inclination angle calibration device and method are proposed, by calculating the sensitivity coefficient of the thrust measuring balance in each direction according to the output value and the known force, and correcting the thrust measuring balance according to the sensitivity coefficient and the initial zero point value to obtain a calibrated measurement value, so as to eliminate the initial zero point change caused by inclined use and improve the measurement accuracy. Summary of the invention
[0003] In order to overcome the problem that the thrust measurement balance calibration method under the existing technology is often only performed for vertical or horizontal states, there is a lack of effective means for calibration in an inclined state, which leads to errors in the measurement results. When the thrust measurement balance is used at an inclined angle, the initial zero point changes due to the change in the direction of the force surface.
[0004] The technical solution of the present invention is: a method for calibrating the tilt angle of a thrust measuring balance, comprising the following steps: S1: Determine the tilt angle of the thrust measuring balance and set the calibration device according to the tilt angle; S2: Install the thrust measuring balance on the calibration device and adjust it to a predetermined tilt angle; S3: Under no external force, perform zero point calibration on the thrust measurement balance and record the initial zero point value; S4: Apply a known force to the thrust measuring balance and record the output values in each direction; S5: Calculate the sensitivity coefficient of the thrust measuring balance in each direction according to the output value and the known force; S6: According to the sensitivity coefficient and the initial zero point value, the thrust measurement balance is corrected to obtain a calibrated measurement value.
[0005] Preferably, the calibration device in step S1 comprises a support frame and an angle adjustment mechanism, the support frame is used to support the thrust measurement balance, and the angle adjustment mechanism is used to adjust the tilt angle of the thrust measurement balance.
[0006] Preferably, the angle adjustment mechanism includes a rotating shaft and a locking device, the rotating shaft is connected to the support frame, the thrust measuring balance is installed on the rotating shaft, and the locking device is used to lock the rotating shaft after adjusting to a predetermined tilt angle to ensure that the thrust measuring balance remains stable during the calibration process.
[0007] Preferably, in step S3, the zero point calibration includes performing zero point calibration in each measuring direction of the thrust measurement balance and recording the initial zero point value in each direction; the specific steps are as follows: S301: Determine a measurement direction that needs to be calibrated for zero point, where the measurement direction includes three orthogonal directions: X, Y, and Z; S302: For each measuring direction, a zero point calibration operation is performed respectively; wherein, in the X direction, it is ensured that no external force acts on the thrust measuring balance, and the initial zero point value in this direction is recorded; the direction is switched to the Y direction, and it is also ensured that no external force acts, and the initial zero point value in the Y direction is recorded; the same zero point calibration operation is performed in the Z direction, and the initial zero point value in the Z direction is recorded; S303: Accurately record the initial zero point value obtained in each measuring direction.
[0008] Preferably, the known force application method in step S4 includes applying a known force in each measuring direction of the thrust measurement balance and recording the output value in each direction; the specific steps are as follows: S401: Determine the magnitude of the known force applied in each measuring direction (X, Y, Z directions) according to the measuring range and calibration requirements of the thrust measuring balance; S402: Selecting the force applying device as a standard weight; S403: installing a force-applying device at a measuring point in the X direction of the thrust measuring balance, applying a known force, and maintaining the force for a period of time to ensure that the thrust measuring balance can respond stably; S404: Record the output value of the thrust measurement balance in the X direction; S405: Move the force-applying device to the Y-direction measuring point of the thrust measuring balance, repeat steps S403-S404, apply a known force, and record the output value in the Y direction; S406: Move the force-applying device to the Z-direction measuring point of the thrust measuring balance, repeat steps S403-S404, apply a known force, and record the output value in the Z direction.
[0009] Preferably, the sensitivity coefficient calculation method in step S5 includes: calculating the sensitivity coefficient in each direction by least square method according to the output value in each direction and the known force; the specific steps are as follows: S501: The output value in each direction and the corresponding known force value are combined into data pairs, forming n data pairs (F_xi, O_xi), (F_yi, O_yi) and (F_zi, O_zi); where O is the output value and F is the applied force; S502: It is assumed that there is a linear relationship between the output value of the thrust measurement balance and the applied force, that is, O=K*F+b; wherein K is the sensitivity coefficient and b is the offset; S503: Perform linear regression analysis on the data pairs in each direction using the least square method, input the data pair (F_i, O_i), output the sensitivity coefficient K and the offset b, and find a straight line (i.e., determine the values of K and b) so that the sum of the squares of the vertical distances (i.e., residuals) from all data points to the straight line is minimized; S504: extracting a sensitivity coefficient K from the calculation result as the sensitivity coefficient in the direction; S505: Perform the above calculations on the three directions of X, Y, and Z respectively to obtain their respective sensitivity coefficients K_x, K_y, and K_z.
[0010] Preferably, the correction method in step S6 includes: establishing a correction formula according to the sensitivity coefficient and the initial zero point value, substituting the original output value of the thrust measurement balance into the correction formula to obtain a calibrated measurement value.
[0011] Preferably, the correction formula in step S6 is: ; in, is the measured value after calibration, is the original output value, is the initial zero value, is the sensitivity coefficient.
[0012] Preferably, the method further includes the step of verifying the calibrated thrust measuring balance, specifically, applying a known force to the thrust measuring balance, comparing the difference between the calibrated measurement value and the known force, and if the difference is within the allowable range, the calibration is successful; otherwise, the calibration step is repeated.
[0013] A thrust measuring balance tilt angle calibration device comprises a calibration assembly for executing any of the calibration methods described above and a three-component measuring balance; the three-component measuring balance comprises an upper plate, a lower plate and a three-component force sensor; a three-component sensor is arranged below the upper plate, a lower plate is arranged below the three-component sensor, eight groups of three-component sensors are arranged, and the eight groups of three-component force sensors are arranged in a symmetrical ring shape; mounting screw holes are provided on the upper plate, and the centers of the mounting screw holes are respectively distributed in a ring structure between the upper plate and the lower plate at a position relationship of 22.5° with the centers of the eight three-component force sensors; the three-component force sensor is used to decompose force and torque into three components in a Cartesian coordinate system; a cross beam loading fixture is arranged above the upper plate.
[0014] Beneficial effects of the present invention: The method comprises the following steps: determining the tilt angle of a thrust measuring balance and setting a calibration device according to the tilt angle; installing the thrust measuring balance on the calibration device and adjusting it to a predetermined tilt angle; performing zero point calibration on the thrust measuring balance without external force and recording the initial zero point value; applying a known force to the thrust measuring balance and recording the output value in each direction; calculating the sensitivity coefficient of the thrust measuring balance in each direction according to the output value and the known force; correcting the thrust measuring balance according to the sensitivity coefficient and the initial zero point value and obtaining the calibrated measurement value; thereby eliminating the initial zero point change caused by tilted use and improving the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 Shown is a schematic flow chart of the steps of the method for calibrating the tilt angle of a thrust measurement balance of the present invention; Figure 2 Shown is a schematic diagram of the three-dimensional structure of a thrust measuring balance tilt angle calibration device of the present invention; Explanation of the reference numerals: 1. upper plate; 2. lower plate; 3. three-component sensor; 4. mounting screw holes; 5. cross beam loading fixture. DETAILED DESCRIPTION
[0016] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.
[0017] See also Figure 1-2 The present invention provides an embodiment: a method for calibrating the tilt angle of a thrust measuring balance, comprising the following steps: S1: Determine the tilt angle of the thrust measuring balance and set the calibration device according to the tilt angle; S2: Install the thrust measuring balance on the calibration device and adjust it to a predetermined tilt angle; S3: Under no external force, perform zero point calibration on the thrust measurement balance and record the initial zero point value; S4: Apply a known force to the thrust measuring balance and record the output values in each direction; S5: Calculate the sensitivity coefficient of the thrust measuring balance in each direction according to the output value and the known force; S6: According to the sensitivity coefficient and the initial zero point value, the thrust measurement balance is corrected to obtain a calibrated measurement value.
[0018] Preferably, the calibration device in step S1 comprises a support frame and an angle adjustment mechanism, the support frame is used to support the thrust measurement balance, and the angle adjustment mechanism is used to adjust the tilt angle of the thrust measurement balance.
[0019] Preferably, the angle adjustment mechanism includes a rotating shaft and a locking device, the rotating shaft is connected to the support frame, the thrust measuring balance is installed on the rotating shaft, and the locking device is used to lock the rotating shaft after adjusting to a predetermined tilt angle to ensure that the thrust measuring balance remains stable during the calibration process.
[0020] Preferably, in step S3, the zero point calibration includes performing zero point calibration in each measuring direction of the thrust measurement balance and recording the initial zero point value in each direction; the specific steps are as follows: S301: Determine a measurement direction that needs to be calibrated for zero point, where the measurement direction includes three orthogonal directions: X, Y, and Z; S302: For each measuring direction, a zero point calibration operation is performed respectively; wherein, in the X direction, it is ensured that no external force acts on the thrust measuring balance, and the initial zero point value in this direction is recorded; the direction is switched to the Y direction, and it is also ensured that no external force acts, and the initial zero point value in the Y direction is recorded; the same zero point calibration operation is performed in the Z direction, and the initial zero point value in the Z direction is recorded; S303: Accurately record the initial zero point value obtained in each measuring direction.
[0021] Preferably, the known force application method in step S4 includes applying a known force in each measuring direction of the thrust measurement balance and recording the output value in each direction; the specific steps are as follows: S401: Determine the magnitude of the known force applied in each measuring direction (X, Y, Z directions) according to the measuring range and calibration requirements of the thrust measuring balance; S402: Selecting the force applying device as a standard weight; S403: installing a force-applying device at a measuring point in the X direction of the thrust measuring balance, applying a known force, and maintaining the force for a period of time to ensure that the thrust measuring balance can respond stably; S404: Record the output value of the thrust measurement balance in the X direction; S405: Move the force-applying device to the Y-direction measuring point of the thrust measuring balance, repeat steps S403-S404, apply a known force, and record the output value in the Y direction; S406: Move the force-applying device to the Z-direction measuring point of the thrust measuring balance, repeat steps S403-S404, apply a known force, and record the output value in the Z direction.
[0022] Preferably, the sensitivity coefficient calculation method in step S5 includes: calculating the sensitivity coefficient in each direction by least square method according to the output value in each direction and the known force; the specific steps are as follows: S501: The output value in each direction and the corresponding known force value are combined into data pairs, forming n data pairs (F_xi, O_xi), (F_yi, O_yi) and (F_zi, O_zi); where O is the output value and F is the applied force; S502: It is assumed that there is a linear relationship between the output value of the thrust measurement balance and the applied force, that is, O=K*F+b; wherein K is the sensitivity coefficient and b is the offset; S503: Perform linear regression analysis on the data pairs in each direction using the least square method, input the data pair (F_i, O_i), output the sensitivity coefficient K and the offset b, and find a straight line (i.e., determine the values of K and b) so that the sum of the squares of the vertical distances (i.e., residuals) from all data points to the straight line is minimized; S504: extracting a sensitivity coefficient K from the calculation result as the sensitivity coefficient in the direction; S505: Perform the above calculations on the three directions of X, Y, and Z respectively to obtain their respective sensitivity coefficients K_x, K_y, and K_z.
[0023] Preferably, the correction method in step S6 includes: establishing a correction formula according to the sensitivity coefficient and the initial zero point value, substituting the original output value of the thrust measurement balance into the correction formula to obtain a calibrated measurement value.
[0024] Preferably, the correction formula in step S6 is: ; in, is the measured value after calibration, is the original output value, is the initial zero value, is the sensitivity coefficient.
[0025] Preferably, the method further includes the step of verifying the calibrated thrust measuring balance, specifically, applying a known force to the thrust measuring balance, comparing the difference between the calibrated measurement value and the known force, and if the difference is within the allowable range, the calibration is successful; otherwise, the calibration step is repeated.
[0026] A thrust measuring balance tilt angle calibration device comprises a calibration assembly for executing any of the calibration methods described above and a three-component measuring balance; the three-component measuring balance comprises an upper plate 1, a lower plate 2 and a three-component force sensor 3; a three-component sensor 3 is arranged below the upper plate 1, a lower plate 2 is arranged below the three-component sensor 3, eight groups of three-component sensors 3 are arranged, and the eight groups of three-component force sensors 3 are arranged in a symmetrical ring shape; mounting screw holes 4 are opened on the upper plate 1, and the centers of the mounting screw holes 4 are respectively distributed in a ring structure between the upper plate 1 and the lower plate 2 at a position relationship of 22.5° with the centers of the eight three-component force sensors 3; the three-component force sensor 3 is used to decompose force and torque into three components in a Cartesian coordinate system; a cross beam loading fixture 5 is arranged above the upper plate 1.
[0027] Example 1 Optionally, when performing the tilt angle calibration of the thrust measurement balance, the specific steps include: A1: Determine the tilt angle and set up the calibration device: First, determine the tilt angle of the thrust measuring balance to be 45° according to the test requirements, and build a calibration device, which includes a support frame and an angle adjustment mechanism; the support frame is used to stably support the thrust measuring balance, and the angle adjustment mechanism is used to accurately adjust the tilt angle of the thrust measuring balance; A2: Installation and adjustment of the tilt angle: Install the thrust measuring balance on the rotating shaft of the calibration device and fix it with a locking device to ensure that the thrust measuring balance will not shake or shift during the calibration process; use the angle adjustment mechanism to adjust the thrust measuring balance to the predetermined tilt angle of 45° and lock it with the locking device; A3: Zero point calibration: Under no external force, perform zero point calibration on the thrust measurement balance; specifically, perform zero point calibration in each measurement direction (such as X, Y, and Z directions) and record the initial zero point value in each direction; A4: Apply known force and record output value: Apply known force in each measuring direction of the thrust measuring balance through standard weights, and record the output value of the thrust measuring balance in each direction. These output values will be used for subsequent calculation of sensitivity coefficient; A5: According to the output value in each direction and the known force, the sensitivity coefficient in each direction is calculated by mathematical methods such as the least square method. The sensitivity coefficient reflects the response degree of the thrust measurement balance to the force. A6: According to the calculated sensitivity coefficient and initial zero value, establish a correction formula: ; Substitute the original output value of the thrust measuring balance into the correction formula to obtain the calibrated measurement value; A7: Apply a known force to the calibrated thrust measurement balance again, and compare the difference between the calibrated measured value and the known force; if the difference is within the allowable range (such as less than or equal to 0.5% FS), the calibration is successful; otherwise, the calibration steps need to be repeated until the accuracy requirements are met; It can be concluded from the above embodiments that the method for calibrating the tilt angle of a thrust measuring balance provided by the present invention can effectively solve the problem of initial zero point change caused by the change in the direction of the force-bearing surface when the thrust measuring balance is used at a tilt angle.
[0028] Example 2 Optionally, in high-precision measurement fields such as aircraft engine testing and automobile collision experiments, the accuracy of the thrust measurement balance is crucial; however, when the thrust measurement balance is in a tilted state, due to the change in the direction of the force-bearing surface, its initial zero point will change, thereby affecting the measurement accuracy; to solve this problem, a thrust measurement balance tilt angle calibration method proposed by the present invention is adopted; In the aircraft engine test, a thrust measuring balance with a measuring range of 1000N and a resolution requirement of 0.1N is calibrated at a tilt angle of 45°. Due to the complex environment of aircraft engine testing, the thrust measuring balance needs to withstand forces of various directions and magnitudes, so the calibration accuracy thereof is required to be extremely high. Traditional calibration methods are often only applicable to vertical or horizontal states and cannot meet the calibration requirements in a tilted state. Therefore, a thrust measuring balance tilt angle calibration method proposed in the present invention is adopted to ensure that the thrust measuring balance can maintain high accuracy even at a tilt angle of 45°. In the process of determining the tilt angle and setting the calibration device, first, according to the test requirements, the tilt angle of the thrust measuring balance is determined to be 45°; then, the calibration device is built, which includes a support frame and an angle adjustment mechanism; the support frame is made of high-strength material and can firmly support the thrust measuring balance to ensure that it does not shake or move during the calibration process; the angle adjustment mechanism is used to accurately adjust the tilt angle of the thrust measuring balance to ensure that it reaches the required 45°; when building the calibration device, the support frame is fixed to the ground by anchor bolts to ensure that it is stable and motionless; the angle adjustment mechanism adopts a worm gear structure, which can achieve fine-tuning of the tilt angle to ensure the accuracy of the calibration; When installing and adjusting the tilt angle, install the thrust measuring balance on the rotating shaft of the calibration device and fix it with a locking device; during the installation process, check the installation position and direction of the balance to ensure that it remains perpendicular to the calibration device and that the force-bearing surface is consistent with the expected direction; then, use the angle adjustment mechanism to adjust the thrust measuring balance to a 45° tilt angle and fix it with a locking device to ensure that the balance does not move or change angle during the calibration process; When performing zero point calibration, the thrust measurement balance is calibrated without external force. First, the initial zero point values in the three directions of X, Y, and Z are recorded respectively. These zero point values are the basis of the output value when the balance is not subjected to any external force. In this example, it is assumed that the initial zero point values are: 0.0N in the X direction, 0.0N in the Y direction, and 0.0N in the Z direction. These zero point values serve as the basis for subsequent calibration and correction. In order to ensure the accuracy of the zero-point calibration process, the balance is fully preheated and stabilized before the zero-point calibration to ensure that its output value is stable and reliable; at the same time, the method of taking the average value of multiple measurements is adopted to reduce the influence of random errors on the calibration results; When applying a known force and recording the output value, a known force is applied in the three directions of X, Y, and Z respectively, and the output value of the thrust measurement balance in each direction is recorded; in this example, standard weights of 100N, 200N, 300N, 400N, and 500N are applied in each direction respectively, and the output value of the balance in each direction is recorded; these output values will be used for the subsequent calculation of the sensitivity coefficient and the correction formula; when applying a known force, ensure that the applied force is perpendicular to the force-bearing surface of the balance, and the magnitude of the force is accurately controllable; at the same time, the method of multiple application and recording is adopted to reduce the influence of accidental errors on the calibration results; The known forces applied in each direction and the output value recording results are shown in the following table:
[0029] When calculating the sensitivity coefficient, the least square method is used to perform linear regression analysis on the recorded data to calculate the sensitivity coefficient in each direction; the sensitivity coefficient is an important parameter reflecting the relationship between the output value of the balance and the input force; in this example, the calculated sensitivity coefficients are as follows: Kx = 1.02, Ky = 0.98, Kz = 1.01; these sensitivity coefficients will be used to subsequently correct and calibrate the output value of the balance; When calculating the sensitivity coefficient, the least square method is used for linear regression analysis. This method can effectively reduce the impact of random errors on the calibration results and improve the accuracy and reliability of calibration. At the same time, the calculated sensitivity coefficients are verified and compared many times to ensure their accuracy and reliability. When performing correction and calibration, a correction formula is established based on the sensitivity coefficient and the initial zero point value, and the original output value of the thrust measurement balance is substituted into the correction formula for correction; the correction formula is: calibrated measurement value = (original output value - initial zero point value) / sensitivity coefficient; through the correction formula, the original output value of the balance can be corrected to a measurement value closer to the true value; Among them, for an original output value of 102N in the X direction, it can be substituted into the correction formula for correction: the calibrated measurement value = (102-0.0) / 1.02=100N; in this way, a measurement value closer to the true value is obtained; During the correction and calibration process, it is ensured that the correction formula can accurately reflect the relationship between the balance output value and the input force, and is applicable to forces of different directions and magnitudes; at the same time, the corrected measurement values are verified and compared multiple times to ensure their accuracy and reliability; Finally, a known force is applied again to the calibrated thrust measuring balance to compare the difference between the calibrated measured value and the known force. In this example, the verification results show that the difference between the calibrated measured value and the known force is within 0.5%FS, which meets the accuracy requirements. During the verification process, a variety of methods and means are used for comparison and verification, including applying and measuring forces of different sizes and directions, and comparing balances of different models and standards. Through these methods and means, the calibration effect can be comprehensively evaluated, and it is ensured that the calibrated thrust measuring balance has high accuracy and reliability. Among them, the comparison between the measured value after calibration and the known force is shown in the following table:
[0030] Comparing the method of the present invention with the prior art, it can be concluded that the method of the present invention has significant advantages; firstly, in terms of calibration angle, the method of the present invention can realize calibration at a tilt angle of 45°, while the prior art is only applicable to vertical or horizontal states; this makes the method of the present invention have a wider scope of application and higher flexibility; secondly, in terms of zero point calibration, the method of the present invention can perform zero point calibration in each direction respectively, while the prior art usually only performs single direction calibration, which makes the method of the present invention more accurately reflect the initial zero point value of the balance in each direction, and improve the accuracy and reliability of calibration; in addition, in terms of sensitivity coefficient calculation and correction method, the method of the present invention also has significant advantages. By calculating the sensitivity coefficient by the least square method and establishing a correction formula for correction, the method of the present invention can more accurately reflect the relationship between the output value of the balance and the input force, and can effectively correct and calibrate the original output value; finally, in terms of calibration accuracy, the method of the present invention has high accuracy and reliability. Through multiple verifications and comparisons, it is concluded that the difference between the calibrated measurement value and the known force is within 0.5%FS, which meets the accuracy requirements; while the prior art often has large errors and uncertainties; It can be concluded from the above application examples that the thrust measuring balance tilt angle calibration method provided by the present invention can effectively solve the problem of initial zero point change caused by change in the direction of the force surface when the thrust measuring balance is used at a tilt angle of 45°; compared with the prior art, the method of the present invention has higher calibration accuracy and a wider range of applications, and can meet the high-precision calibration requirements for thrust measuring balances in fields such as aviation engine testing and automobile collision experiments.
[0031] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of those skilled in the art without departing from the spirit of the present invention.
Claims
1. A method for calibrating the tilt angle of a thrust measuring balance, characterized in that: The following steps are included: S1: Determine the tilt angle of the thrust measuring balance and set the calibration device according to the tilt angle; S2: Install the thrust measuring balance on the calibration device and adjust it to a predetermined tilt angle; S3: Under no external force, perform zero point calibration on the thrust measurement balance and record the initial zero point value; S4: Apply a known force to the thrust measuring balance and record the output values in each direction; S5: Calculate the sensitivity coefficient of the thrust measuring balance in each direction according to the output value and the known force; S6: According to the sensitivity coefficient and the initial zero point value, the thrust measurement balance is corrected to obtain a calibrated measurement value.
2. A method for calibrating the tilt angle of a thrust measuring balance according to claim 1, characterized in that: The calibration device in step S1 includes a support frame and an angle adjustment mechanism, wherein the support frame is used to support the thrust measurement balance, and the angle adjustment mechanism is used to adjust the tilt angle of the thrust measurement balance.
3. A method for calibrating the tilt angle of a thrust measuring balance according to claim 2, characterized in that: The angle adjustment mechanism includes a rotating shaft and a locking device. The rotating shaft is connected to the support frame, and the thrust measuring balance is installed on the rotating shaft. The locking device is used to lock the rotating shaft after adjusting to a predetermined tilt angle to ensure that the thrust measuring balance remains stable during the calibration process.
4. A method for calibrating the tilt angle of a thrust measurement balance according to claim 1, characterized in that: In step S3, the zero point calibration includes performing zero point calibration in each measuring direction of the thrust measurement balance and recording the initial zero point value in each direction; the specific steps are as follows: S301: Determine a measurement direction that needs to be calibrated for zero point, where the measurement direction includes three orthogonal directions: X, Y, and Z; S302: For each measuring direction, a zero point calibration operation is performed respectively; wherein, in the X direction, it is ensured that no external force acts on the thrust measuring balance, and the initial zero point value in this direction is recorded; the direction is switched to the Y direction, and it is also ensured that no external force acts, and the initial zero point value in the Y direction is recorded; the same zero point calibration operation is performed in the Z direction, and the initial zero point value in the Z direction is recorded; S303: Accurately record the initial zero point value obtained in each measuring direction.
5. The method for calibrating the tilt angle of a thrust measuring balance according to claim 1, characterized in that: The known force application method in step S4 includes applying a known force in each measuring direction of the thrust measurement balance and recording the output value in each direction; the specific steps are as follows: S401: Determine the magnitude of the known force applied in each measuring direction (X, Y, and Z directions) according to the range and calibration requirements of the thrust measurement balance; S402: Selecting the force applying device as a standard weight; S403: installing a force-applying device at a measuring point in the X direction of the thrust measuring balance, applying a known force, and maintaining the force for a period of time to ensure that the thrust measuring balance can respond stably; S404: Record the output value of the thrust measurement balance in the X direction; S405: Move the force-applying device to the Y-direction measuring point of the thrust measuring balance, repeat steps S403-S404, apply a known force, and record the output value in the Y direction; S406: Move the force-applying device to the Z-direction measuring point of the thrust measuring balance, repeat steps S403-S404, apply a known force, and record the output value in the Z direction.
6. A method for calibrating the tilt angle of a thrust measurement balance according to claim 1, characterized in that: The sensitivity coefficient calculation method in step S5 includes: according to the output value in each direction and the known force, the sensitivity coefficient in each direction is calculated by the least square method; the specific steps are as follows: S501: The output value in each direction and the corresponding known force value are combined into data pairs, forming n data pairs (F_xi, O_xi), (F_yi, O_yi) and (F_zi, O_zi); where O is the output value and F is the applied force; S502: It is assumed that there is a linear relationship between the output value of the thrust measurement balance and the applied force, that is, O=K*F+b; wherein K is the sensitivity coefficient and b is the offset; S503: Perform linear regression analysis on the data pairs in each direction using the least square method, input the data pair (F_i, O_i), output the sensitivity coefficient K and the offset b, and find a straight line (i.e., determine the values of K and b) so that the sum of the squares of the vertical distances (i.e., residuals) from all data points to the straight line is minimized; S504: extracting a sensitivity coefficient K from the calculation result as the sensitivity coefficient in the direction; S505: Perform the above calculations on the three directions of X, Y, and Z respectively to obtain their respective sensitivity coefficients K_x, K_y, and K_z.
7. A method for calibrating the tilt angle of a thrust measurement balance according to claim 1, characterized in that: The correction method in step S6 includes: establishing a correction formula according to the sensitivity coefficient and the initial zero point value, substituting the original output value of the thrust measurement balance into the correction formula, and obtaining a calibrated measurement value.
8. A thrust measuring balance tilt angle calibration device and method according to claim 7, characterized in that: The correction formula in step S6 is: ； in, is the measured value after calibration, is the original output value, is the initial zero value, is the sensitivity coefficient.
9. A method for calibrating the tilt angle of a thrust measurement balance according to claim 1, characterized in that: The method includes the steps of verifying the thrust measuring balance after calibration, specifically: applying a known force on the thrust measuring balance, comparing the difference between the measured value after calibration and the known force, if the difference is within the allowable range, the calibration is successful; otherwise, the calibration step is repeated.
10. A thrust measuring balance tilt angle calibration device, characterized in that: The invention comprises a calibration assembly for executing the calibration method according to any one of claims 1 to 9 and a three-component measuring balance; the three-component measuring balance comprises an upper plate (1), a lower plate (2) and a three-component force sensor (3); a three-component sensor (3) is arranged below the upper plate (1), a lower plate (2) is arranged below the three-component sensor (3), eight groups of the three-component sensors (3) are arranged, and the eight groups of the three-component force sensors (3) are arranged in a symmetrical ring shape; mounting screw holes (4) are provided on the upper plate (1), and the mounting screw holes (4) are distributed in sequence in the ring structure between the upper plate (1) and the lower plate (2) at a positional relationship of 22.5° with the centers of the eight three-component force sensors (3); the three-component force sensor (3) is used to decompose force and torque into three components in a Cartesian coordinate system; a cross beam loading fixture (5) is arranged above the upper plate (1).