Electrostatic accelerometer attitude-adjusting vibration isolation test swing table

Abstract

The application relates to a static electrodynamic accelerometer attitude adjusting vibration isolation test swing table, which solves the problem that the attitude of a static electrodynamic accelerometer cannot be adjusted in a test swing table in an experiment, and the swing table comprises a closed chamber, the closed chamber is fixedly installed on the ground and internally fixedly installed with a suspension frame, the suspension frame is installed at the top with a flexible deflection, and the other end of the flexible deflection is installed with a rigid swing table frame, the bottom of the rigid swing table frame is fixedly installed with a bearing swing table, and the top surface of the bearing swing table is fixedly installed with a static electrodynamic accelerometer attitude adjusting device; the bearing swing table can freely swing around a suspension point, the inclination angle of the swing table can be adjusted by adjusting the position of a counterweight on the swing table, the inclination angle of the swing table is changed, the attitude position of a to-be-tested static electrodynamic accelerometer is adjusted, the position of the to-be-tested static electrodynamic accelerometer on the swing table is adjusted through a three-dimensional displacement adjusting platform, a better swing table vibration isolation effect is obtained, and the ground performance test demand of a high-precision static electrodynamic accelerometer is met.

Description

Technical Field

[0001] This invention relates to the field of ground vibration isolation systems and ground research technology of electrostatic accelerometers, specifically to an electrostatic accelerometer attitude adjustment vibration isolation test platform. Background Technology

[0002] Electrostatic accelerometers, based on capacitive displacement sensing and electrostatic feedback control technology, are characterized by high accuracy, small size, and the ability to simultaneously measure six degrees of freedom, and are widely used in various space programs. Since the 1990s, electrostatic accelerometers have been successfully used as important payloads in space projects such as satellite gravity measurement, testing of Newton's inverse square law, and gravitational wave detection. Their technology has matured continuously, and they have become one of the important payloads for space science missions. Currently, the resolution level of electrostatic accelerometers has increased from 10^-3 Å in the early days to... -10 m / s 2 / Hz 1 / 2 The level of magnitude has been continuously improved to 10. -15 m / s 2 / Hz 1 / 2 The scale is significant. To ensure the reliability of such high-precision electrostatic accelerometers, ground-based resolution testing and sensitivity calibration are crucial. During testing, the impact of ambient vibration noise on ground-based electrostatic accelerometer measurements must be considered. Ground-based scientific experiments are inevitably affected by ground pulsations; even in quiet areas, ground pulsation noise can still reach as high as 10⁻⁶ Hz within the sub-Hertz measurement frequency band of the electrostatic accelerometer. -8 m / s 2 / Hz 1 / 2 This noise level is on the order of magnitude higher than the inherent noise level of the electrostatic accelerometer itself, which poses a significant limitation to ground performance testing of electrostatic accelerometers. Therefore, developing a ground vibration isolation system is essential for ground-based research on electrostatic accelerometers.

[0003] For traditional vibration isolation systems, the isolation frequency band depends on its natural frequency, offering almost no isolation effect for frequencies below this band. Currently, the natural frequencies of commercial vibration isolation platforms are unlikely to reach the operating frequency band of electrostatic accelerometers, failing to meet the resolution testing requirements of electrostatic accelerometers with measurement frequency bands as low as millihertz. Furthermore, in ground performance testing of electrostatic accelerometers, due to their extremely high resolution and very small range, the electrostatic accelerometer must be mounted on the test platform with a high degree of horizontality. It is highly sensitive to the tilt angle of the test platform; the acceleration component of gravity introduced by the platform's tilt along the platform surface can easily cause the electrostatic accelerometer to exceed its range and malfunction, thus hindering further ground-based research such as electrostatic accelerometer resolution testing. While test platforms such as suspended composite vibration isolation pendulum tables and locally optimized high-precision electrostatic accelerometer test pendulum tables possess some ability to isolate ground vibrations, they lack the ability to adjust the installation attitude of the electrostatic accelerometer and cannot be used for electrostatic accelerometer sensitivity calibration experiments. Therefore, it is necessary to explore new methods, break through the limitations of traditional vibration isolation systems, consider the needs of test platform tilt angle adjustment, and develop a test platform system that can provide vibration isolation effects over a wide frequency band while also enabling precise adjustment of the electrostatic accelerometer mounting attitude.

[0004] In view of the above, we provide an electrostatic accelerometer attitude adjustment vibration isolation test platform to solve the above problems. Summary of the Invention

[0005] To address the above issues and overcome the shortcomings of existing technologies, this invention provides an electrostatic accelerometer attitude adjustment and vibration isolation test platform. It employs a flexible, flexural suspension platform, allowing the platform to swing in response to horizontal ground vibrations. The horizontal component of gravity introduced by the platform's tilt balances these vibrations. A three-dimensional displacement adjustment platform on the platform adjusts the accelerometer's position, aligning the accelerometer's measuring point with the platform's center of mass. This reduces the coupling of torsional acceleration to horizontal acceleration. Simultaneously, the height of the measuring point is adjusted to fall at the impact center of the platform, achieving high-frequency vibration suppression at that point. This allows for the identification of a measuring point where horizontal acceleration noise remains low across a wide frequency band, enabling electrostatic accelerometer performance testing. Furthermore, based on the center-of-mass adjustment method, a linear displacement stage is installed on the platform. Adjusting the mass of the counterweight alters the mass distribution of the platform system, changing its tilt angle and allowing for precise attitude adjustment of the electrostatic accelerometer under test, ensuring it operates normally within its measurement range. Meanwhile, by quantitatively adjusting the position of the counterweight, the tilt angle of the pendulum is also quantitatively adjusted. This tilt angle signal can be used as a calibration signal for the electrostatic accelerometer, thereby enabling the electrostatic accelerometer sensitivity calibration experiment.

[0006] An electrostatic accelerometer attitude adjustment vibration isolation test platform is characterized by comprising a sealed chamber, a flexible flexure, a suspension frame, a rigid platform frame, a load-bearing platform, and an electrostatic accelerometer attitude adjustment device. The sealed chamber is rigidly connected to the ground, and the bottom of the sealed chamber is rigidly connected to the bottom of the suspension frame. The top of the suspension frame is rigidly connected to one end of the flexible flexure, and the other end of the flexible flexure is rigidly connected to the platform frame. The bottom of the platform frame is rigidly connected to the load-bearing platform, and the electrostatic accelerometer attitude adjustment device is fixedly installed on the top surface of the load-bearing platform.

[0007] Preferably, the electrostatic accelerometer attitude adjustment device includes an angle measuring device, an electrostatic accelerometer to be measured, a three-dimensional displacement adjustment platform, a monitoring and control platform, a counterweight, and a linear displacement stage; the angle measuring device is fixedly installed on one side of the top wall of the bearing pendulum, the three-dimensional displacement adjustment platform is fixedly installed at the center of the bearing pendulum and the electrostatic accelerometer to be measured is fixedly installed on the top wall of the three-dimensional displacement adjustment platform, the linear displacement stage is fixedly installed on the side of the bearing pendulum away from the angle measuring device, and a counterweight is fixedly installed on the top of the linear displacement stage.

[0008] Preferably, the three-dimensional displacement adjustment platform includes three sets of displacement stages that can move in three directions: horizontal, orthogonal, and vertical. The displacement stages are precisely adjusted using a guide rail and lead screw type movement adjustment method.

[0009] Preferably, the mass of the counterweight is less than the total mass of the load-bearing pendulum, the angle measuring device, the electrostatic accelerometer to be measured, the three-dimensional displacement adjustment platform, and the linear displacement stage.

[0010] Preferably, the monitoring and control platform is connected to the electrostatic accelerometer under test, the three-dimensional displacement adjustment platform, and the linear displacement stage via wires.

[0011] Preferably, the sealed chamber is a closed cavity.

[0012] The beneficial effects of the above technical solution are as follows:

[0013] The electrostatic accelerometer attitude adjustment vibration isolation test platform of the present invention consists of mechanical components, an angle measuring device, a three-dimensional displacement adjustment platform, a linear displacement stage, and a monitoring and control platform. Its structure is relatively simple and easy to implement. The entire device adopts a passive vibration isolation scheme, eliminating the need for control circuitry and avoiding the introduction of additional noise. The present invention utilizes the three-dimensional displacement adjustment platform to adjust the position of the accelerometer on the platform, ensuring that the accelerometer measuring point is located at the impact center on the vertical line of the platform's center of mass, thereby achieving the optimal acceleration noise level. Simultaneously, it incorporates the principle of balancing the horizontal vibration noise of the ground by utilizing the horizontal component of gravitational acceleration generated by the platform's tilt, resulting in a weak response of the electrostatic accelerometer under test to horizontal ground vibrations across a wide frequency range. Furthermore, by using a linear displacement stage to adjust the position of the counterweight on the bearing pendulum, the tilt angle of the pendulum is changed, thereby adjusting the attitude position of the electrostatic accelerometer under test. At the same time, by quantitatively adjusting the position of the counterweight, the tilt angle of the pendulum can be quantitatively adjusted. The tilt angle of the pendulum can be recorded by an angle measuring device. This tilt angle signal can be used as a tilt calibration signal for the sensitivity calibration of the electrostatic accelerometer, thus realizing the sensitivity calibration function of the electrostatic accelerometer. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0015] 1. Sealed chamber; 2. Flexible bending; 3. Suspension frame; 4. Rigid pendulum frame; 5. Bearing pendulum; 6. Electrostatic accelerometer attitude adjustment device; 61. Angle measuring device; 62. Electrostatic accelerometer under test; 63. Three-dimensional displacement adjustment platform; 64. Monitoring and control platform; 65. Counterweight; 66. Linear displacement stage. Detailed Implementation

[0016] The foregoing and other technical contents, features and effects of the present invention are described in conjunction with the appendix below. Figure 1 The detailed description of the embodiments will make this clear. All structural details mentioned in the following embodiments are based on the accompanying drawings.

[0017] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings.

[0018] This embodiment provides a vibration isolation test platform for electrostatic accelerometer attitude adjustment, as shown in the attached figure. Figure 1 As shown, the system includes a sealed chamber 1, a flexible flexure 2, a suspension frame 3, a rigid pendulum frame 4, a load-bearing pendulum 5, and an electrostatic accelerometer attitude adjustment device 6. The sealed chamber 1 is rigidly connected to the ground, and the bottom of the sealed chamber 1 is rigidly connected to the bottom of the suspension frame 3. The top of the suspension frame 3 is rigidly connected to one end of the flexible flexure 2, and the other end of the flexible flexure 2 is rigidly connected to the pendulum frame 4. The bottom of the pendulum frame 4 is rigidly connected to the load-bearing pendulum 5. The electrostatic accelerometer attitude adjustment device 6 is fixedly installed on the top surface of the load-bearing pendulum 5. The flexible flexure 2 allows the load-bearing pendulum 5 and the electrostatic accelerometer attitude adjustment device 6 installed on it to swing freely in the vertical plane. The sealed chamber 1 is a closed cavity, forming a sealed frame system to reduce the influence of airflow on low-frequency vibrations.

[0019] The electrostatic accelerometer attitude adjustment device 6 includes an angle measuring device 61, an electrostatic accelerometer under test 62, a three-dimensional displacement adjustment platform 63, a monitoring and control platform 64, a counterweight 65, and a linear displacement stage 66. The angle measuring device 61 is fixedly installed on one side of the top wall of the bearing pendulum 5. The three-dimensional displacement adjustment platform 63 is fixedly installed at the center of the bearing pendulum 5, and the electrostatic accelerometer under test 62 is fixedly installed on the top wall of the three-dimensional displacement adjustment platform 63. The three-dimensional displacement adjustment platform 63 can be used as a three-axis flexible displacement stage. The three-dimensional displacement adjustment platform 63 is rigidly connected to the bearing pendulum 5 and the electrostatic accelerometer under test 62. The linear displacement stage 66 is fixedly installed on the side of the bearing pendulum 5 away from the angle measuring device 61. The counterweight 65 is fixedly installed on the top of the linear displacement stage 66. The linear displacement stage 66 is rigidly connected to the bearing pendulum 5 and the counterweight 65.

[0020] The linear displacement stage 66 can drive the counterweight 65 to move along the surface of the bearing platform 5, change the mass distribution within the entire bearing platform 5, adjust the tilt angle of the bearing platform 5, and thus adjust the installation posture of the electrostatic accelerometer 62 to be measured installed on the bearing platform 5.

[0021] The three-dimensional displacement adjustment platform 63 includes three sets of displacement stages that can move in three directions: horizontal, orthogonal, and vertical. The displacement stages are precisely adjusted using a guide rail and lead screw type movement adjustment method.

[0022] The mass of the counterweight 65 is less than the total mass of the bearing platform 5, the angle measuring device 61, the electrostatic accelerometer under test 62, the three-dimensional displacement adjustment platform 63, and the linear displacement stage 66; the mass of the counterweight 65 is more than three orders of magnitude smaller than the bearing platform 5 and the load on it, and can be adjusted to a sub-micro-radius attitude angle, so as to realize the function of adjusting the attitude angle of the installation platform by the electrostatic accelerometer in ground testing.

[0023] The linear displacement stage 66 can quantitatively move the position of the counterweight 65 on the supporting pendulum platform 5, thereby quantitatively changing the tilt angle of the supporting pendulum platform 5. The angle measuring device 61 measures and records the change in tilt angle of the supporting pendulum platform 5 caused by the movement of the counterweight 65. This tilt angle change signal is used as the calibration signal in the calibration experiment of the electrostatic accelerometer 62 under test, realizing the sensitivity calibration function of the electrostatic accelerometer.

[0024] The monitoring and control platform 64 is connected to the electrostatic accelerometer 62 under test, the three-dimensional displacement adjustment platform 63, and the linear displacement stage 66 via wires. The monitoring and control platform 64 can read the real-time data of the electrostatic accelerometer 62 under test and control the movement of the three-dimensional displacement adjustment platform 63 and the linear displacement stage 66. The monitoring and control platform 64 reads the real-time output data of the electrostatic accelerometer 62 under test through data cables, obtains the attitude position of the accelerometer, and then adjusts the position of the counterweight 65 through the linear displacement stage 66 to change the tilt angle of the supporting pendulum 5, thereby adjusting the electrostatic accelerometer 62 under test to a suitable attitude position.

[0025] The monitoring and control platform 64 reads the real-time output data of the electrostatic accelerometer 62 under test through the data cable, and obtains the distance of the electrostatic accelerometer 62 under test from the vertical line of the center of mass of the pendulum. Then, through the three-dimensional displacement adjustment platform 63, the measuring point of the electrostatic accelerometer 62 under test can be adjusted to the vertical line of the center of mass of the pendulum to suppress the coupling noise of the torsional motion of the pendulum.

[0026] The monitoring and control platform 64 reads the real-time output data of the electrostatic accelerometer 62 under test through the data cable, and obtains the distance of the electrostatic accelerometer 62 under test from the impact center of the pendulum. Then, through the three-dimensional displacement adjustment platform 63, the measuring point of the electrostatic accelerometer 62 under test can be adjusted to the impact center of the pendulum to suppress high-frequency vibration coupling noise.

[0027] When the ground vibrates horizontally, the suspension frame 3 vibrates with the ground. The rigid pendulum frame 4, the bearing pendulum 5, and the electrostatic accelerometer attitude adjustment device 6 will be subjected to an inertial force in the opposite direction to the horizontal vibration of the ground, causing them to swing around the suspension point. As a result, the bearing pendulum 5 will tilt. The horizontal component of gravitational acceleration generated by the tilt of the pendulum itself will be used to balance the noise of the horizontal vibration of the ground.

[0028] Because of the flexible flexure suspension method, when the rigid pendulum frame 4, the supporting pendulum platform 5, and the electrostatic accelerometer attitude adjustment device 6 are subjected to external disturbances, in addition to swinging around the suspension point, they will also rotate around the vertical line of the pendulum platform's center of mass. The rotational acceleration will be coupled to the horizontal direction through centripetal acceleration. By reading the data measured by the electrostatic accelerometer 62 under test through the monitoring and control platform 64, the three-dimensional displacement adjustment platform 63 is controlled to move in two horizontal orthogonal directions according to the accelerometer data, adjusting the horizontal position of the accelerometer on the supporting pendulum platform 5 so that the measuring point of the electrostatic accelerometer 62 under test coincides with the vertical line of the pendulum platform's center of mass. This can suppress the rotational acceleration coupling noise and improve the noise test level of the electrostatic accelerometer.

[0029] Meanwhile, the monitoring and control platform 64 reads the data measured by the electrostatic accelerometer 62 under test, and controls the three-dimensional displacement adjustment platform 63 to move in the vertical direction according to the accelerometer data, adjusting the height of the accelerometer on the bearing pendulum 5 so that the measurement point of the electrostatic accelerometer 62 under test coincides with the impact center of the pendulum, which can greatly reduce the response to high-frequency vibration and improve the noise test level of the electrostatic accelerometer.

[0030] Electrostatic accelerometers are highly sensitive to the tilt angle of the test platform. Due to their extremely high resolution and very small measurement range, the electrostatic accelerometer must be mounted on the test platform with a high degree of horizontality. The gravitational acceleration component along the test platform surface introduced by the tilt of the test platform can easily cause the electrostatic accelerometer to exceed its measurement range and malfunction, thus preventing further ground-based research such as electrostatic accelerometer resolution testing. In ground-based testing of electrostatic accelerometers, the monitoring and control platform 64 reads the data measured by the electrostatic accelerometer 62 under test. Based on the real-time data of the accelerometer, the attitude position of the accelerometer is determined. The position of the counterweight 65 is adjusted by the linear displacement stage 66, and the tilt angle of the supporting pendulum stage 5 is precisely adjusted to adjust the electrostatic accelerometer 62 under test to a suitable attitude position, ensuring its normal operation on the ground for further ground-based research.

[0031] Besides the resolution test of the electrostatic accelerometer, the sensitivity calibration experiment is equally important, as it determines the accuracy of the acceleration signal measured by the electrostatic accelerometer. For conducting ground calibration experiments of the electrostatic accelerometer, it is necessary to be able to precisely apply a quantitative external acceleration signal to the electrostatic accelerometer. The position of the counterweight 65 on the supporting pendulum platform 5 can be quantitatively moved using the linear displacement stage 66, thereby quantitatively changing the tilt angle of the supporting pendulum platform 5, and thus applying a quantitative gravitational acceleration component signal to the electrostatic accelerometer. The change in the tilt angle of the supporting pendulum platform 5 caused by the movement of the counterweight 65 is then measured and recorded using the angle measuring device 61. This tilt angle change signal can be used as the calibration signal in the calibration experiment of the electrostatic accelerometer 62 under test, conducting the electrostatic accelerometer sensitivity calibration experiment.

[0032] The above is merely for illustrating the present invention. It should be understood that the present invention is not limited to the above embodiments, and various modifications that conform to the spirit of the present invention are within the protection scope of the present invention.

Claims

1. A vibration isolation test platform for electrostatic accelerometer attitude adjustment, characterized in that, The device includes a sealed chamber (1), a flexible flexure (2), a suspension frame (3), a rigid pendulum frame (4), a load-bearing pendulum (5), and an electrostatic accelerometer attitude adjustment device (6). The sealed chamber (1) is rigidly connected to the ground and the bottom of the sealed chamber (1) is rigidly connected to the bottom of the suspension frame (3). The top of the suspension frame (3) is rigidly connected to one end of the flexible flexure (2) and the other end of the flexible flexure (2) is rigidly connected to the pendulum frame (4). The bottom of the pendulum frame (4) is rigidly connected to the load-bearing pendulum (5). The electrostatic accelerometer attitude adjustment device (6) is fixedly installed on the top surface of the load-bearing pendulum (5). The electrostatic accelerometer attitude adjustment device (6) includes an angle measuring device (61), an electrostatic accelerometer to be measured (62), a three-dimensional displacement adjustment platform (63), a monitoring and control platform (64), a counterweight (65), and a linear displacement stage (66); the angle measuring device (61) is fixedly installed on one side of the top wall of the bearing pendulum (5), the three-dimensional displacement adjustment platform (63) is fixedly installed at the center of the bearing pendulum (5), and the electrostatic accelerometer to be measured (62) is fixedly installed on the top wall of the three-dimensional displacement adjustment platform (63), the linear displacement stage (66) is fixedly installed on the side of the bearing pendulum (5) away from the angle measuring device (61), and the counterweight (65) is fixedly installed on the top of the linear displacement stage (66); The linear displacement stage (66) adjusts the attitude of the electrostatic accelerometer (62) under test by changing the tilt angle of the supporting pendulum stage (5) by quantitatively moving the position of the counterweight (65); The counterweight (65) is moved quantitatively on the bearing platform (5) by the linear displacement stage (66), thereby quantitatively changing the tilt angle of the bearing platform (5), and thus applying a quantitative gravitational acceleration component signal to the electrostatic accelerometer (62) under test. The angle measuring device (61) records the tilt angle change signal for the sensitivity calibration of the electrostatic accelerometer (62) under test.

2. The electrostatic accelerometer attitude adjustment vibration isolation test platform according to claim 1, characterized in that, The three-dimensional displacement adjustment platform (63) includes three sets of displacement stages that can move in three directions: horizontal, orthogonal, and vertical.

3. The electrostatic accelerometer attitude adjustment vibration isolation test platform according to claim 1, characterized in that, The mass of the counterweight (65) is less than the total mass of the bearing pendulum (5), the angle measuring device (61), the electrostatic accelerometer to be tested (62), the three-dimensional displacement adjustment platform (63) and the linear displacement stage (66).

4. The electrostatic accelerometer attitude adjustment vibration isolation test platform according to claim 1, characterized in that, The monitoring and control platform (64) is connected to the electrostatic accelerometer (62), the three-dimensional displacement adjustment platform (63), and the linear displacement stage (66) respectively via wires.

5. The electrostatic accelerometer attitude adjustment vibration isolation test platform according to claim 1, characterized in that, The sealed chamber (1) is a closed cavity.

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