Electrostatic lunar surface vector gravimeter

Abstract

The present application belongs to the field of gravity acceleration measurement, and specifically discloses an electrostatic lunar surface vector gravimeter. The present application first makes it approximately horizontal through the attitude adjustment and control platform subsystem, and then obtains three-axis acceleration data through the electrostatic acceleration sensor subsystem, thereby realizing the gravity value vector output under tilt measurement conditions, and has strong environmental adaptability. In addition, the attitude adjustment and control platform subsystem directly reuses the three-axis acceleration data of the sensitive mass for attitude adjustment, which not only discards the gyroscope and accelerometer in the attitude adjustment and control platform subsystem, but also realizes the lightweight, miniaturization and low power consumption of the lunar surface gravity vector measurement device; it also avoids the differences in acceleration data from different sources and improves the accuracy of the measurement results. The measurement device designed in the present application has a relative measurement accuracy of up to ten microgammas and a miniaturized size.

Description

Technical Field

[0001] The present application belongs to the field of gravity acceleration measurement, and more specifically, to an electrostatic lunar surface vector gravimeter. Background Art

[0002] With the continuous advancement of human space technology, deep space exploration missions targeting the Moon are gradually entering the surface sampling and survey phase, preparing for the next phase of landing missions. Accurately determining the lunar gravity field is crucial for studying the Moon's internal structure and determining the lunar elevation datum and geoid.

[0003] Existing gravimeters are primarily used on the Earth's surface. They are categorized as absolute and relative. Absolute gravimeters can meet the accuracy requirements for lunar gravity measurements, but they are bulky. Relative gravimeters, such as small spring-loaded MEMS gravimeters, are susceptible to temperature fluctuations, making bias stability difficult to control. They can only measure in a single vertical direction and require a stable horizontal platform. Superconducting gravimeters require extremely low temperatures, which are difficult to achieve on the lunar surface.

[0004] In addition, there are also some accelerometers used in space stations, but their main design direction is high resolution, and their range is low, generally 10 -7 -10 -5 m / s 2 , and the weight measurement requirement on the moon is 2m / s 2 , so it cannot be satisfied.

[0005] Therefore, it is urgent to develop a gravimeter that can measure gravitational acceleration on the lunar surface. Summary of the Invention

[0006] In response to the defects of the existing technology, the purpose of this application is to provide an electrostatic lunar surface vector gravimeter, which aims to solve the problem that the existing gravimeters cannot meet the measurement accuracy and volume of the lunar surface.

[0007] A first aspect of the present application relates to an electrostatic lunar surface vector gravimeter, comprising:

[0008] An electrostatic acceleration sensor subsystem is used to measure the three-axis acceleration data of the sensitive mass through differential capacitance and transmit it to the data fusion processing subsystem;

[0009] The attitude adjustment and control platform subsystem is used to obtain the three-axis acceleration data of the sensitive mass from the data fusion subsystem, adjust the installation plane of the electrostatic acceleration sensor subsystem to make it approximately horizontal during the measurement of gravity acceleration on the lunar surface, and transmit the attitude data to the data fusion subsystem;

[0010] The data fusion processing subsystem is used to decompose the vertical component of the three-axis acceleration data and vector synthesize it into gravity acceleration; compare and analyze the three-axis acceleration data and attitude data to evaluate the stability of the gravimeter measurement results, and output the gravity acceleration when stable as the final result.

[0011] In some embodiments, the electrostatic acceleration sensor subsystem includes:

[0012] A sensitive probe module comprising a sensitive mass and a capacitor plate, wherein the sensitive mass is configured to move away from an equilibrium position due to the gravitational acceleration of the lunar surface after release, and the capacitor plate is configured to cause a corresponding change in differential capacitance when the distance between the sensitive mass and the capacitor plate changes;

[0013] A locking and releasing module is used to keep the sensitive mass in a balanced position in the locked state and release the sensitive mass in the released state;

[0014] The servo control module includes a high-voltage control module and a normal-voltage control module. The high-voltage control module is used to detect the electrical signal corresponding to the differential capacitance change of the upper and lower capacitor plates, generate an electrostatic force acting on the sensitive mass, and return it to a vertical equilibrium position. The normal-voltage control module is used to respectively detect the electrical signal corresponding to the differential capacitance change of the left and right capacitor plates and the front and rear capacitor plates, generate an electrostatic force acting on the sensitive mass, and return it to a horizontal equilibrium position.

[0015] It should be noted that this application adds a high-voltage control module to detect the electrical signal corresponding to the change in differential capacitance between the upper and lower capacitor plates, generating an electrostatic force on the sensitive mass to return it to its vertical equilibrium position. Compared to existing technologies, this solves the problem of using electrostatic accelerometers in gravity environments by balancing gravity with electrostatic force.

[0016] In some embodiments, the electrostatic acceleration sensor subsystem further includes:

[0017] The temperature control module is symmetrically arranged relative to the sensitive mass and is used to detect and control the working environment temperature fluctuation of the sensitive probe module to not exceed 0.1°C.

[0018] It should be noted that if the temperature fluctuation range exceeds 0.1°C, it will cause slight expansion or contraction of the sensitive mass, affecting measurement accuracy. This application uses a temperature control module to control the temperature fluctuation range of the sensitive probe module's working environment to within 0.1°C, reducing the measurement instability of the sensitive mass caused by changes in the lunar environment temperature.

[0019] In some embodiments, the sensitive mass and the capacitor plate frame are both made of glass-ceramic.

[0020] It should be noted that the present application preferably uses glass-ceramic to make the sensitive mass and capacitor plate frame, and its expansion coefficient is 10 -7 / K level, high stability, and reduced sensitivity of sensitive mass deformation to changes in lunar ambient temperature.

[0021] In some embodiments, the sensitive mass surface is gold plated, and the vertical axis is insulated from the horizontal axis.

[0022] It should be noted that the present application prefers the sensitive mass of the above design to achieve the application of bias voltage on its surface and separation of normal pressure and high pressure control to achieve high-pressure suspension.

[0023] In some embodiments, the electrostatic acceleration sensor subsystem further includes:

[0024] The closed cavity is used to enclose the remaining part of the electrostatic acceleration sensor subsystem to prevent dust from falling on the sensitive mass surface; the closed cavity is non-vacuum.

[0025] It should be noted that there is no need to provide a vacuum cavity for the sensitive probe module, which can further reduce the volume and weight of the gravimeter.

[0026] In some embodiments, the data fusion processing subsystem evaluates the stability of the gravimeter measurement results by:

[0027] According to the triaxial acceleration data, calculate the two inclination angles between the sensitive mass and the horizontal plane;

[0028] Extracting two inclination angles between the installation plane of the electrostatic acceleration sensor subsystem and the horizontal plane from the attitude data;

[0029] An F test is performed on the two groups of corresponding inclination angle data of the electrostatic acceleration sensor subsystem and the attitude adjustment and control platform subsystem. If the P values ​​of both groups of tests are greater than 0.05, the gravimeter measurement results are judged to be stable; otherwise, they are judged to be unstable.

[0030] It should be noted that this application preferably uses the above-mentioned indicators and means to judge stability. Compared with the traditional gravimeter that evaluates stability through the Allan variance of long-term measurement data, it solves the stability evaluation of gravity measurement results with small sample data and realizes rapid evaluation of weight measurement results.

[0031] In some embodiments, the area of ​​the selected single capacitor plate is greater than 150 mm 2 The distance between the capacitor plate and the sensitive mass is less than 30μm, the weight of the sensitive mass is less than 25g, and the bias voltage and feedback voltage of the sensitive mass are within 100V, making the relative measurement accuracy of the electrostatic lunar surface vector gravimeter at the level of ten microgal and the range of 2m / s 2 .

[0032] In some embodiments, the volume of each component in the electrostatic acceleration sensor subsystem does not exceed 10 cubic centimeters, and the total volume of the electrostatic acceleration sensor subsystem does not exceed 10 cubic centimeters.

[0033] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the existing technologies:

[0034] Compared to the existing technology that requires the gravimeter to be equipped with a completely independent stable platform, this application proposes an electrostatic lunar surface vector gravimeter, which is first made approximately horizontal through the attitude adjustment and control platform subsystem, and then obtains three-axis acceleration data through the electrostatic acceleration sensor subsystem, thereby realizing the gravity value vector output under tilt measurement conditions, and has strong environmental adaptability. In addition, the attitude adjustment and control platform subsystem directly reuses the three-axis acceleration data of the sensitive mass for attitude adjustment, which not only discards the gyroscope and accelerometer in the attitude adjustment and control platform subsystem, but also realizes the lightweight, miniaturization and low power consumption of the lunar surface gravity vector measurement device; it also avoids the differences in acceleration data from different sources and improves the accuracy of the measurement results. The measurement device designed in this application has a relative measurement accuracy of up to ten microgammas and a miniaturized size. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic structural diagram of the electrostatic lunar surface vector gravimeter provided in an embodiment of the present application.

[0036] Figure 2 It is a structural diagram of the data fusion processing subsystem provided in an embodiment of the present application.

[0037] Figure 3 This is a structural diagram of the attitude adjustment and control platform subsystem provided in an embodiment of the present application.

[0038] Figure 4 This is a schematic diagram of the three-axis gravity acceleration vector output provided in an embodiment of the present application.

[0039] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0040] 1 is the electrostatic acceleration sensor subsystem, 2 is the attitude adjustment and control platform subsystem, 3 is the data fusion processing subsystem, and 4 is the power module;

[0041] 11 is a sensitive probe module, 11-1 is a sensitive mass, and 11-2 is a capacitor plate;

[0042] 12 is a locking and releasing module;

[0043] 13 is a servo control module, 13-1 is a high-pressure control module, and 13-2 is a normal-pressure control module;

[0044] 14 is a temperature control module;

[0045] 15 is a closed cavity;

[0046] 21 is the frame and installation module, 21-1 is the pitch axis frame, 21-2 is the roll axis frame, 21-3 is the stable platform bracket, and 21-4 is the vibration isolation base;

[0047] 22 is the sensing and driving module, 22-1 is the tilt sensor, 22-2 is the DC torque motor,

[0048] 31 is a digital-to-analog conversion module, 32 is a data fusion processor, 33 is a data storage module, and 34 is a display and operation panel. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0050] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0051] like Figure 1 As shown, the present application provides an electrostatic lunar surface vector gravimeter, comprising: an electrostatic acceleration sensor subsystem 1, an attitude adjustment and control platform subsystem 2, a data fusion processing subsystem 3 and a power module 4.

[0052] The electrostatic acceleration sensor subsystem 1 is used to measure the three-axis acceleration data of the sensitive mass through differential capacitance and transmit it to the data fusion processing subsystem 3;

[0053] Attitude adjustment and control platform subsystem 2 is used to obtain triaxial acceleration data of the sensitive mass from the data fusion subsystem, adjust the installation plane of the electrostatic acceleration sensor subsystem to make it approximately horizontal during the measurement of gravity acceleration on the lunar surface, and transmit the attitude data to data fusion subsystem 3;

[0054] The data fusion processing subsystem 3 is used to decompose the vertical component of the three-axis acceleration data and vector synthesize it into gravity acceleration; compare and analyze the three-axis acceleration data and attitude data to evaluate the stability of the gravimeter measurement results, and output the gravity acceleration when stable as the final result.

[0055] like Figure 1As shown, the electrostatic acceleration sensor subsystem 1 is installed above the attitude adjustment and control platform subsystem 2, the data fusion processing subsystem 3 is suspended above the electrostatic acceleration sensor subsystem 1 through a stable platform bracket, and the power module 4 is installed on the vibration isolation base of the attitude adjustment and control platform subsystem.

[0056] In some embodiments, the electrostatic acceleration sensor subsystem 1 includes:

[0057] Sensitive probe module 11, comprising a sensitive mass 11-1 and a capacitor plate 11-2. The sensitive mass is configured to move away from its equilibrium position due to the gravitational acceleration of the lunar surface after release, and the capacitor plate is configured to change its differential capacitance accordingly when the distance between the sensitive mass and the capacitor plate changes.

[0058] A locking and releasing module 12, used to keep the sensitive mass in a balanced position in a locked state and release the sensitive mass in a released state;

[0059] The servo control module 13 includes a high-voltage control module 13-1 and a normal-voltage control module 13-2. The high-voltage control module is used to detect the electrical signal corresponding to the differential capacitance change of the upper and lower capacitor plates, generate an electrostatic force acting on the sensitive mass, and return it to a vertical equilibrium position. The normal-voltage control module is used to detect the electrical signal corresponding to the differential capacitance change of the left and right capacitor plates and the front and rear capacitor plates, respectively, and generate an electrostatic force acting on the sensitive mass, and return it to a horizontal equilibrium position.

[0060] like Figure 1 As shown, the sensitive probe module is installed within the enclosed cavity 15 and includes a sensitive mass, capacitor plates, and a probe frame 11-3. The sensitive mass is placed between the capacitor plates; three sets of capacitor plates are fixed to the probe frame, one set for each axis, and each set includes at least one pair of plates. The temperature control module is symmetrically mounted on the upper and lower surfaces of the enclosed cavity 15; the locking and release modules are mounted on opposite sides of the enclosed cavity 15; and the high-pressure control module and the normal-pressure control module are mounted on opposite sides of the enclosed cavity 15.

[0061] In some embodiments, the shape of the sensitive mass can be a solid (hollow) cube, a cuboid or a sphere, and is designed as a replaceable component, which can be selected according to the gravity acceleration value on the lunar surface. The sensitive probe is designed to be miniaturized, taking a cube as an example, the size is 2cm 3 The sensitive mass and the capacitor plate frame are both made of glass-ceramic.

[0062] In some embodiments, the sensitive mass surface is gold-plated, and the vertical and horizontal axes are insulated. Different bias voltages are applied via gold wires. The capacitor plate frame is also made of microcrystalline glass, and the capacitor plate contour (three axes are perpendicular and orthogonal) is milled and then gold-plated.

[0063] In some embodiments, the locking and releasing module locks the sensitive mass when not in a measurement state, for example, during transportation, and releases the sensitive mass at the start of a measurement operation.

[0064] In some embodiments, the electrostatic acceleration sensor subsystem further includes a temperature control module 14 symmetrically arranged relative to the sensitive mass, for detecting and controlling the working environment temperature fluctuation of the sensitive probe module to not exceed 0.1°C.

[0065] In some embodiments, the electrostatic acceleration sensor subsystem further includes a closed cavity 15 for enclosing the remaining portion of the electrostatic acceleration sensor subsystem to prevent dust from settling on the sensitive mass surface. The closed cavity is non-vacuum-free and can be a cubic, rectangular, or cylindrical structure.

[0066] The servo control module utilizes thick-film integration for miniaturization. The high-voltage control module generates a strong electrostatic force (generated by a suspension voltage of approximately 200V) to balance the gravitational acceleration of the lunar surface. It includes a capacitive displacement sensor, a control unit, and a high-voltage feedback actuator. The constant-voltage control module generates a weak electrostatic force (generated by a 0-90V voltage) for capacitor plate servo control. It also includes a capacitive displacement sensor, a control unit, and a constant-voltage feedback actuator.

[0067] Attitude adjustment and control platform subsystem 2 is used to adjust the attitude of the cavity and provide high precision level (10 -7 m / s 2 / Hz 1 / 2 )Measure attitude and low vibration (noise less than 10 -7 m / s 2 / Hz 1 / 2 ) Measurement environment, such as Figure 3 As shown, it includes a frame and mounting module 21 and a sensing and driving module 22.

[0068] The frame and mounting module 21 is used to provide a system mounting frame and contact the lunar surface to provide a low-vibration measurement environment. It includes: a pitch-axis frame 21-1, a roll-axis frame 21-2, a stable platform bracket 21-3, and a vibration isolation base 21-4. The vibration isolation base is located at the bottom of the entire subsystem and contacts the lunar surface. The stable platform bracket is mounted on the vibration isolation base. The pitch-axis frame and the roll-axis frame are mounted on the two horizontal axes of the stable platform bracket and are in the same plane.

[0069] The sensing and driving module 22 includes an inclination sensor 22-1 and a DC torque motor 22-2. A DC torque motor and an inclination sensor are respectively installed on the pitch axis frame and the roll axis frame to provide high-precision horizontal measurement posture.

[0070] like Figure 2 As shown, the data fusion processing subsystem 3 includes: a digital-to-analog conversion module 31, a data fusion processor 32, a data storage module 33 and a display and operation panel 34.

[0071] The digital-to-analog conversion module 31 is used for data conversion and transmission between the three subsystems;

[0072] A data fusion processor 32 is used to fuse and analyze the three-axis acceleration data with the attitude adjustment and control platform attitude information, and output the gravity measurement value;

[0073] A data storage module 33 is used to store gravity measurement data to meet long-term measurement needs;

[0074] The display and operation panel 34 is used to provide visual information and convenient operations.

[0075] The electrostatic acceleration sensor subsystem 1 transmits the measured three-axis acceleration data of the sensitive mass to the digital-to-analog conversion module 31. The attitude adjustment and control platform subsystem 2 transmits the attitude data to the data fusion processing subsystem 3 and obtains the three-axis acceleration data of the sensitive mass from the data fusion processing subsystem 3.

[0076] The power supply module 4 is used to meet the power requirements of various systems of the gravimeter.

[0077] In actual operation, the sensitive mass in the electrostatic acceleration sensor subsystem applies a high-frequency carrier signal V through the metal wire. p and a DC bias voltage V b , where V b The purpose is to linearize the normal pressure and high pressure feedback execution units, and their stability is directly related to the resolution of the accelerometer; V p The purpose is to make the capacitive displacement sensing unit operate at a high frequency, so as to effectively suppress the low-frequency flicker noise of semiconductor devices such as the operational amplifier in the capacitive displacement sensing unit.

[0078] When the electrostatic lunar surface vector gravimeter proposed in this application is placed on the lunar surface for gravity measurement, the working process is as follows: the attitude adjustment and control platform subsystem performs attitude adjustment, and when the two tilt sensor readings in the display and operation panel are near 0, the sensitive mass is released, causing it to displace relative to the capacitor plate and leave the equilibrium position. The capacitance balance between the capacitor plate and the sensitive mass is destroyed at this time, and the capacitance displacement sensing unit tests the offset, and obtains the carrier signal containing the movement of the sensitive mass in different directions through the pre-amplification and AC amplification and signal combination therein, and then multiplies and demodulates it with the excitation signal, and performs low-pass filtering to obtain the low-frequency motion signal of the capacitor plate relative to the sensitive mass movement direction. Subsequently, the feedback control signal V is obtained through the feedback execution unit. fed , using the feedback execution unit to V fed applied to the corresponding capacitor plates, pulling the sensitive mass back to its equilibrium position.

[0079] like Figure 4 As shown, in this closed-loop operating mode, the sensitive mass is always maintained in its equilibrium position. Due to errors in the attitude control and tilt sensor angles of the control platform, the gravitational acceleration on the lunar surface can be derived from the three-axis acceleration data vector of the electrostatic acceleration sensor subsystem. Furthermore, the inclination data is calculated from the three-axis acceleration data of the electrostatic acceleration sensor subsystem and fused with the inclination sensor data (formula shown below) to evaluate the stability of the gravimeter measurement data.

[0080] cos 2 α+cos 2 β+cos 2 γ=1

[0081]

[0082] Among them, F x , F y , F z are the electrostatic forces in the left-right, front-back, and up-down directions of the sensitive mass, respectively; α is the angle between the left-right axis of the sensitive mass and the horizontal plane; β is the angle between the front-back axis of the sensitive mass and the horizontal plane; and γ is the angle between the up-down axis of the sensitive mass and the vertical direction.

[0083] The stability analysis of the vector lunar gravity acceleration and gravimeter data is output through the display and operation panel in the data fusion processing subsystem and stored in the data storage module.

[0084] It should be understood that expressions such as "include" and "may include" used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "include" and / or "have" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0085] In addition, in this application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.

[0086] The directional terms mentioned in the embodiments of the present application, such as "top", "bottom", "inside", "outside", "left", "right", etc., are only references to the directions in the drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0087] In addition, in the embodiments of the present application, the mathematical concepts mentioned include symmetry, equality, parallelism, and perpendicularity. These limitations are all for the current state of the art, rather than being absolutely strict definitions in a mathematical sense. A small amount of deviation is allowed, and it is possible to be approximately symmetric, approximately equal, approximately parallel, or approximately perpendicular. For example, A and B are parallel, which means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 and 10 degrees. A and B are perpendicular, which means that A and B are perpendicular or approximately perpendicular, and the angle between A and B can be between 80 and 100 degrees.

[0088] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An electrostatic lunar surface vector gravimeter, characterized in that: include: An electrostatic acceleration sensor subsystem is used to measure the three-axis acceleration data of the sensitive mass through differential capacitance and transmit it to the data fusion processing subsystem; The attitude adjustment and control platform subsystem is used to obtain the three-axis acceleration data of the sensitive mass from the data fusion subsystem, adjust the installation plane of the electrostatic acceleration sensor subsystem to make it approximately horizontal during the measurement of gravity acceleration on the lunar surface, and transmit the attitude data to the data fusion subsystem; The data fusion processing subsystem is used to decompose the vertical component of the three-axis acceleration data and synthesize it into gravity acceleration; Compare and analyze the three-axis acceleration data and attitude data to evaluate the stability of the gravimeter measurement results, and output the gravitational acceleration when stable as the final result.

2. The electrostatic lunar surface vector gravimeter according to claim 1, wherein: The electrostatic acceleration sensor subsystem includes: A sensitive probe module comprising a sensitive mass and a capacitor plate, wherein the sensitive mass is configured to move away from an equilibrium position due to the gravitational acceleration of the lunar surface after release, and the capacitor plate is configured to cause a corresponding change in differential capacitance when the distance between the sensitive mass and the capacitor plate changes; A locking and releasing module is used to keep the sensitive mass in a balanced position in the locked state and release the sensitive mass in the released state; The servo control module includes a high-voltage control module and a normal-voltage control module. The high-voltage control module is used to detect the electrical signal corresponding to the differential capacitance change of the upper and lower capacitor plates, generate an electrostatic force acting on the sensitive mass, and return it to a vertical equilibrium position. The normal-voltage control module is used to respectively detect the electrical signal corresponding to the differential capacitance change of the left and right capacitor plates and the front and rear capacitor plates, generate an electrostatic force acting on the sensitive mass, and return it to a horizontal equilibrium position.

3. The electrostatic lunar surface vector gravimeter according to claim 2, wherein: The electrostatic acceleration sensor subsystem further includes: The temperature control module is symmetrically arranged relative to the sensitive mass and is used to detect and control the working environment temperature fluctuation of the sensitive probe module to not exceed 0.1°C.

4. The electrostatic lunar surface vector gravimeter according to claim 2, wherein: The sensitive mass and the capacitor plate frame are both made of microcrystalline glass.

5. The electrostatic lunar surface vector gravimeter according to claim 4, wherein: The sensitive mass surface is gold plated and the vertical and horizontal axes are insulated.

6. The electrostatic lunar surface vector gravimeter according to claim 2, wherein: The electrostatic acceleration sensor subsystem further includes: A closed cavity is used to enclose the remaining parts of the electrostatic acceleration sensor subsystem to prevent dust from settling on the sensitive mass surface; The closed cavity is non-vacuum.

7. The electrostatic lunar surface vector gravimeter according to claim 1, wherein: The data fusion processing subsystem evaluates the stability of the gravimeter measurement results in the following ways: According to the triaxial acceleration data, calculate the two inclination angles between the sensitive mass and the horizontal plane; Extracting two inclination angles between the installation plane of the electrostatic acceleration sensor subsystem and the horizontal plane from the attitude data; An F test is performed on the two groups of corresponding inclination angle data of the electrostatic acceleration sensor subsystem and the attitude adjustment and control platform subsystem. If the P values ​​of both groups of tests are greater than 0.05, the gravimeter measurement results are judged to be stable; otherwise, they are judged to be unstable.

8. The electrostatic lunar surface vector gravimeter according to claim 1, wherein: The area of ​​the selected single capacitor plate is greater than 150mm 2 The distance between the capacitor plate and the sensitive mass is less than 30μm, the weight of the sensitive mass is less than 25g, and the bias voltage and feedback voltage of the sensitive mass are within 100V, making the relative measurement accuracy of the electrostatic lunar surface vector gravimeter at the level of ten microgal and the range of 2m / s 2 .

9. The electrostatic lunar surface vector gravimeter according to claim 1, wherein: The volume of each component in the electrostatic acceleration sensor subsystem does not exceed 10 cubic centimeters, and the total volume of the electrostatic acceleration sensor subsystem does not exceed 10 cubic centimeters.

Images