A high frequency dynamic thrust test system

Abstract

This invention relates to a high-frequency dynamic thrust testing system capable of testing dynamic thrust performance and thrust vector performance. The system mainly consists of a thrust test bench, a force vector testing device, a calibration system, and a testing system. The test apparatus is fixedly mounted on the thrust test bench. The thrust generated during operation is transmitted to the force vector testing device. The thrust and pressure signals, after conditioning and amplification, are input along with control signals to the acquisition and processing system for recording the test process. The acquired test data is processed to obtain corresponding engine performance indicators. An in-situ calibration system, composed of a standard strain sensor and a load measuring instrument, is used to calibrate the thrust transmission characteristics of the test bench to obtain the thrust transmission coefficient. This invention enables multi-component force testing of thrust vector control engines, with large test thrust, high test frequency, multiple test directions, and high testing accuracy.

Description

Technical Field

[0001] This invention relates to the field of solid rocket motor technology, and more specifically to a high-frequency dynamic thrust testing system. Background Technology

[0002] The thrust vector control tester achieves thrust vector control by altering the flow of combustion gases within the tester. The thrust vector control tester is characterized by high dynamic performance testing requirements, fast response time, and high testing accuracy. Based on these testing needs, a high-frequency dynamic thrust testing system was designed.

[0003] The existing technical solution uses a solid attitude control tester with a six-component force sensor to test the thrust vector. This test method uses an integrated six-component force sensor in conjunction with software to test the thrust vector. Due to the use of an integrated six-component force sensor, the test flexibility and accuracy are both low, and it is impossible to achieve a large frequency of thrust testing.

[0004] The thrust vector control test chamber achieves thrust vectoring control by altering the flow of combustion gases within the chamber. Compared to traditional test chambers, the thrust variation process of the thrust vector control test chamber is more complex, and the testing requirements for its dynamic performance are also higher. Currently, the thrust vectoring control thrust ranges from a few Newtons to tens of kilonewtons, with response times required to be in the millisecond range. Current testing systems have low accuracy in measuring dynamic characteristics, making it impossible to accurately test the dynamic characteristics of the thrust vector control test chamber. Furthermore, the thrust vector control test chamber involves testing thrust in multiple directions, requiring high testing accuracy. Currently used integrated six-component force sensors have a low testing frequency, making it impossible to evaluate the overall performance of the thrust vector control test chamber. Summary of the Invention

[0005] Based on the above-mentioned technical problems, this invention proposes a high-frequency dynamic thrust testing system to solve the problems of low dynamic characteristic testing accuracy of the currently used testing systems, which cannot accurately test the dynamic characteristics of the thrust vector control tester; and the problem that the current integrated six-component force sensor has a low testing frequency, which cannot evaluate the overall performance of the thrust vector control tester.

[0006] To address the aforementioned technical problems, one objective of this invention is to provide a high-frequency dynamic thrust testing system. This system comprises a calibration system 1, a thrust vector measurement device 2, a thrust test bench 3, a measurement and control system 4, and an industrial control computer 5. The thrust test bench 3 is divided into two layers. The lower layer provides a support platform for installing the main thrust calibration device, and the upper layer provides an installation support platform for the entire thrust test system, which is used to install the thrust vector test device, tester, calibration system and other auxiliary structures. The thrust vector measuring device 2 includes a lower plate 6, a three-part piezoelectric sensor 7, an upper plate 8, and a transition flange 9. The lower plate 6 is connected to the thrust test bench (3) by screws. The three-part piezoelectric sensor 7 is located on the lower plate 6 and is arranged symmetrically. The three-part piezoelectric sensor 7 is connected to the lower plate 6 and the upper plate 8 by screws respectively. The transition flange 9 is fixedly connected to the upper plate 8 by screws. The test instrument for testing is connected to the thrust vector measuring device 2 through the transition flange 9. The measurement and control system 4 uses a data acquisition board to realize multi-channel and different sampling frequency test requirements, and acquires and outputs the electrical signal output by the thrust vector test device 2 to obtain a standard voltage signal that can be recognized by the industrial control computer 5. The calibration system 1 uses a standard force source sensor to calibrate the thrust vector testing device 2 in the X, Y, and Z directions. The internal software of the industrial control computer 5 is used to match the standard voltage signal output by the thrust vector testing device 2 with the force value output by the quasi-force source sensor. The corresponding values ​​form a 3D coefficient matrix. When the multi-dimensional force tester is tested using this invention, the correct force value can be obtained by multiplying the voltage signal output by the thrust vector testing device 2 with the 3D coefficient matrix.

[0007] Furthermore, the thrust test bench has an open interface on its surface to prevent damage to the test bench from the flame of the tester during thrust testing; process holes are designed on the side of the thrust test bench to reduce the impact of stress concentration on the reliability of the test bench; and a T-slot interface with the ground is provided on the lower surface of the thrust test bench.

[0008] Furthermore, the three-force piezoelectric sensor 7 is composed of a preload nut 10, a preload bolt 11, a sensor 12, and a pressure block 13. The combination of the preload nut 10 and the preload bolt 11 is used to apply a preload to the three-force piezoelectric sensor 7 to improve the testing performance of the piezoelectric sensor 7. The application of the preload force releases the charge generated by the three-force piezoelectric sensor 7, so that the three-force piezoelectric sensor 7 can work in the preload state. The sensor 12, as the sensitive element of the force measuring unit, converts the force signal into an electrical signal based on the piezoelectric positive effect. Each sensor 12 in the three-force piezoelectric sensor 7 must be able to measure the three forces to achieve the measurement of multidimensional forces. The pressure block 13 is used to connect with the lower plate 6 and the upper plate 8, and the connection method is bolt fastening.

[0009] Furthermore, in the three-part force piezoelectric sensor 7, one unit crystal group is composed of two piezoelectric quartz crystal wafers assembled together. The three-part force piezoelectric sensor 7 serves as the sensitive element of the force measuring unit, and converts the force signal into an electrical signal based on the piezoelectric positive effect.

[0010] Furthermore, the three-component piezoelectric sensor consists of two yx unit crystal groups capable of measuring tangential force, with their maximum sensitivity axes at 90° to each other, and an xy unit crystal group capable of measuring axial force, thereby realizing the measurement of thrust.

[0011] The above-described one or more technical solutions of the present invention have at least one or more of the following technical effects: This invention enables multi-component force testing of the thrust vector control tester, with large test thrust, high test frequency, multiple test directions, and high test accuracy.

[0012] This invention enables force measurement in the X, Y, and Z directions using different quartz crystal cuts, achieving high accuracy and large measured force values. The invention employs an open structure, allowing for diverse test apparatus shapes and enabling the measurement of thrust values ​​in multiple directions. Attached Figure Description

[0013] Figure 1 Schematic diagram of high-frequency dynamic thrust testing system: Figure 2 Schematic diagram of the thrust vector measurement device: Figure 3 Schematic diagram of a three-force piezoelectric sensor; Figure 4 A schematic diagram of the wafer cutting shape commonly used in piezoelectric sensors; Figure 5 Schematic diagram of the three-part force piezoelectric sensor; Among them: 1-calibration system, 2-thrust vector measuring device, 3-thrust test bench, 4-measurement and control system, 5-industrial computer, 6-lower plate, 7-three-part force piezoelectric sensor, 8-upper plate, 9-adapter flange, 10-preload nut, 11-preload bolt, 12-sensor, 13-pressure block. Detailed Implementation

[0014] This invention relates to a high-frequency dynamic thrust testing system, capable of testing dynamic thrust performance and thrust vector performance. The system mainly consists of a thrust test bench, a force vector testing device, a calibration system, and a testing system. It can meet the testing requirements of large thrust and high testing frequency. Its working principle is as follows: the test instrument is fixedly mounted on the thrust test bench. The thrust generated by the instrument during operation is transmitted to the force vector testing device. The thrust and pressure signals, after conditioning and amplification, are input along with control signals to the acquisition and processing system to record the test process. The acquired test data is processed to obtain the corresponding performance indicators of the test instrument. An in-situ calibration system composed of a standard strain sensor and a load measuring instrument is used to calibrate the thrust transmission characteristics of the test bench to obtain the thrust transmission coefficient.

[0015] The test apparatus is mounted on the upper surface of the thrust test bench. The thrust generated during operation is transmitted to the force vector testing device. The thrust signal, after conditioning and amplification, is input to the acquisition and processing system. The acquired test data is processed to obtain the thrust values ​​on the corresponding coordinate axes (X, Y, Z axes) of the test apparatus. System calibration was completed before the thrust test, using standard force sensors to calibrate the thrust values ​​on different coordinate axes (X, Y, Z axes). Calibration yielded force value matrices in different directions, i.e., force matrices obtained by applying standard forces in different directions (X, Y, Z axes). During the test, physical quantities in different directions (X, Y, Z axes) are measured. Multiplying the measured physical quantities by the inverse of the force value matrix yields the thrust values ​​in different directions (X, Y, Z axes).

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments obtained. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0017] like Figure 1 As shown, the high-frequency dynamic thrust testing system consists of a calibration system 1, a thrust vector measurement device 2, a thrust test bench 3, a measurement and control system 4, and an industrial control computer 5. The thrust test bench 3 has a two-layer structure: the lower layer provides a support platform for installing the main thrust calibration device, and the upper layer provides an installation support platform for the entire thrust testing system, used to install the thrust vector measurement device, the test apparatus, the calibration system, and other auxiliary structures (standard force sensor support, thrust device). To accommodate subsequent dimensional changes to the test apparatus, the thrust test bench has an open interface. To prevent damage to the test bench from the test apparatus's flame during thrust testing, there are no other auxiliary components on the thrust test bench. Process holes are designed on the side of the thrust test bench to reduce the impact of stress concentration on the bench's reliability. The lower surface of the thrust test bench has a T-slot interface for connecting to the ground, and the upper surface of the test bench has a flange interface for connecting to the test apparatus. The thrust test bench has dimensions of 940mm × 940mm, and multiple threaded holes are pre-drilled on the surface for connection to the test apparatus. To ensure testing accuracy, the flatness of the test platform surface must not exceed 0.2 mm. The dimensions of the lower platform of the thrust test bench are 1200mm × 1200mm. The upper panel of the test bench is bolted to the thrust vector measuring device 2.

[0018] The thrust vector measuring device 2 includes a lower plate 6, three-component piezoelectric sensors 7, an upper plate 8, and a connecting flange 9. The lower plate 6 is connected to the thrust test bench 3 by screws. The three-component piezoelectric sensors 7 are located on the lower plate 6 and arranged symmetrically. The three-component piezoelectric sensors 7 are connected to both the lower plate 6 and the upper plate 8 by screws. The connecting flange 9 is fixedly connected to the upper plate 8 by screws. The connecting flange 9 allows the test apparatus to be connected to the thrust vector measuring device 2. The connecting flange 9 has an open structure, allowing for fixed connections with test apparatuses of different structural shapes.

[0019] The three-force piezoelectric sensor 7 consists of a preload nut 10, a preload bolt 11, a sensor 12, and a pressure block 13. The preload nut 10 and preload bolt 11 are used to apply a preload to the three-force piezoelectric sensor 7 to improve its testing performance. Applying the preload releases the charge generated by the three-force piezoelectric sensor 7, allowing it to operate in a preloaded state. The sensor 12, as the sensitive element of the force measuring unit, converts the force signal into an electrical signal based on the piezoelectric positive effect. Each sensor 12 in the three-force piezoelectric sensor 7 must be able to measure the three forces to achieve multi-dimensional force measurement. The pressure block 13 is used to connect to the lower plate 6 and the upper plate 8 using bolt fastening.

[0020] A redundant design approach is employed for thrust vector measurement, using a four-point support test method for the four three-force piezoelectric sensors 7. The three-force piezoelectric sensors 7 are arranged in a square configuration on the horizontal plane (the sensors operate within the same coordinate system). As the core component of the thrust vector measurement device 2, the three-force piezoelectric sensors 7 utilize the piezoelectric effect of quartz crystals to measure the three forces, thereby achieving multi-dimensional force measurement.

[0021] Different cuts of quartz crystals result in different force-to-electric conversion methods and piezoelectric coefficients, leading to variations in the sensitivity, natural frequency, and force measured by the resulting sensors. Quartz crystals can be classified into X-cut and Y-cut families based on their position in the Cartesian coordinate system. Two commonly used crystal cuts in piezoelectric sensors are the xy-cut (also known as the x0º cut) and the yx-cut (also known as the y0º cut), such as... Figure 4 As shown, xy-cut crystals are suitable for measuring loads acting perpendicularly to the crystal's bearing surface, while yx-cut crystals are used to measure external forces acting parallel to the bearing surface. Furthermore, the piezoelectric coefficient of the xy-cut piezoelectric quartz crystal is d11 = 2.31 × 10⁻¹² (C / N), while that of the yx-cut crystal is d26 = 2d11. With the same number of crystals, the sensor composed of yx-cut crystals has twice the sensitivity of the xy-cut sensor.

[0022] In the three-part force piezoelectric sensor 7, one unit crystal group is composed of two piezoelectric quartz crystal wafers mounted together, which not only simplifies the structure but also doubles the sensitivity. As the sensitive element of the force measuring unit, the three-part force piezoelectric sensor 7 converts force signals into electrical signals based on the piezoelectric positive effect. To achieve thrust measurement, each piezoelectric sensor in the force measuring instrument must be able to measure the three parts of the force. Therefore, each sensor consists of two yx unit crystal groups capable of measuring tangential force, with their maximum sensitivity axes at 90° to each other, and one xy unit crystal group capable of measuring axial force, as shown below. Figure 5 As shown.

[0023] The thrust vector testing device 2 and the thrust test bench 3 form an assembly during testing. After assembly, they must also meet the requirement of not resonating at frequencies of (0-150) Hz. Therefore, modal analysis of the assembly of the test bench and thrust vector testing device was performed using the finite element software ANSYS. The material was defined as Q235 structural steel; the lower surface of the test bench's lower plate was fixed with constraints, and automatic mesh generation was used for modal analysis. The first natural frequency was found to be 244.79 Hz, and the second natural frequency was 244.83 Hz. Since the natural frequencies of the high-frequency dynamic thrust testing system are very high, this ensures that the high-frequency dynamic thrust testing system can meet the thrust testing requirements at higher switching frequencies.

[0024] The measurement and control system 4 uses a data acquisition board to achieve multi-channel, different sampling frequency testing requirements. It acquires and outputs the electrical signal from the thrust vector testing device 2 to obtain a standard voltage signal that the industrial control computer 5 can recognize. The calibration system 1 uses a standard force source sensor to calibrate the thrust vector testing device 2 in the X, Y, and Z directions. Using the internal software of the industrial control computer 5, it maps the standard voltage signal output by the thrust vector testing device 2 to the force value output by the quasi-force source sensor. The mapped values ​​form a 3D coefficient matrix. When using this invention to test the multi-dimensional force tester, multiplying the voltage signal output by the thrust vector testing device 2 by the 3D coefficient matrix yields the correct force value.

[0025] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present invention without departing from the spirit and scope of the embodiments of the present invention. Thus, if these modifications and variations to the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

[0026] The initial setup and testing of this invention have been completed, and the test results meet the expectations.

Claims

1. A high-frequency dynamic thrust testing system, characterized in that, The system consists of a calibration system (1), a thrust vector measurement device (2), a thrust test bench (3), a measurement and control system (4), and an industrial control computer (5). The thrust test bench (3) is divided into two layers. The lower layer provides a support platform for installing the main thrust calibration device, and the upper layer provides an installation support platform for the entire thrust test system, which is used to install the thrust vector test device, test instrument, calibration system and other auxiliary structures. The thrust vector measuring device (2) includes a lower plate (6), a three-part piezoelectric sensor (7), an upper plate (8), and a transition flange (9). The lower plate (6) is connected to the thrust test bench (3) by screws. The three-part piezoelectric sensor (7) is located on the lower plate (6) and arranged symmetrically. The three-part piezoelectric sensor (7) is connected to the lower plate (6) and the upper plate (8) by screws respectively. The transition flange (9) is fixedly connected to the upper plate (8) by screws. The test engine is connected to the thrust vector measuring device (2) through the transition flange (9). The measurement and control system (4) uses a data acquisition board to realize the test requirements of multiple channels and different sampling frequencies, and acquires the electrical signal output by the thrust vector test device (2) to obtain the standard voltage signal that the industrial control computer (5) can recognize. The calibration system (1) uses a standard force source sensor to calibrate the thrust vector test device (2) in the X, Y and Z directions. The internal software of the industrial control computer (5) is used to match the standard voltage signal output by the thrust vector test device (2) with the force value output by the quasi-force source sensor. The corresponding values ​​form a (3) dimension coefficient matrix. When the multi-dimensional force engine is tested using the present invention, the correct force value can be obtained by multiplying the voltage signal output by the thrust vector test device (2) with the (3) dimension coefficient matrix.

2. The high-frequency dynamic thrust testing system according to claim 1, characterized in that: The thrust test bench has an open interface on its surface to prevent damage to the test bench from the flame of the tester during thrust testing; process holes are designed on the side of the thrust test bench to reduce the impact of stress concentration on the reliability of the test bench; and a T-slot interface is provided on the lower surface of the thrust test bench for connection with the ground.

3. The high-frequency dynamic thrust testing system according to claim 1, characterized in that: The three-force piezoelectric sensor (7) consists of a preload nut (10), a preload bolt (11), a sensor (12), and a pressure block (13). The combination of the preload nut (10) and the preload bolt (11) is used to apply a preload to the three-force piezoelectric sensor (7) to improve the test performance of the piezoelectric sensor (7). The loading of the preload force releases the charge generated by the three-force piezoelectric sensor (7), so that the three-force piezoelectric sensor (7) can work in the preload state. The sensor (12) is the sensitive element of the force measuring unit. Based on the piezoelectric positive effect, it converts the force signal into an electrical signal. Each sensor (12) in the three-force piezoelectric sensor (7) must be able to measure the three-dimensional force to achieve the measurement of multi-dimensional force. The pressure block (13) is used to connect with the lower plate (6) and the upper plate (8). The connection method is bolt fastening.

4. The high-frequency dynamic thrust testing system according to claim 3, characterized in that: In the three-part force piezoelectric sensor (7), one unit crystal group is composed of two piezoelectric quartz crystal wafers assembled together. The three-part force piezoelectric sensor (7) serves as the sensitive element of the force measuring unit and converts the force signal into an electrical signal based on the piezoelectric positive effect.

5. The high-frequency dynamic thrust testing system according to claim 4, characterized in that: The three-component piezoelectric sensor consists of two yx unit crystal groups capable of measuring tangential force, with their maximum sensitivity axes at 90° to each other, and an xy unit crystal group capable of measuring axial force, thereby realizing the measurement of thrust.

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