A heavy-float differential vertical gravity gradiometer

Abstract

The application belongs to the technical field of gravity gradient measurement, and specifically discloses a heavy-float differential type vertical gravity gradiometer. The gravity gradiometer comprises a liquid container, a float, a connecting support, a counterweight and a measurement system. The float comprises an upper part submerged, a rod part similar to a buoy and a lower part completely submerged. The float is arranged in the liquid container, one end of the connecting support is fixedly connected to the upper surface of the rod part, the other end of the connecting support is rigidly connected with the counterweight, and the center of mass of the float and the center of mass of the counterweight are located on the same plumb line. The bottom end of the liquid container is fixed, and the liquid container contains liquid with a density greater than that of the float. The body part of the float is suspended in the liquid, the lower half of the rod part of the float is submerged in the liquid, and the upper half is exposed above the liquid surface. The measurement system measures the vertical gravity gradient change information after the gravity gradiometer is moved from a first measurement position to a second measurement position. According to the application, the portability of the instrument can be greatly improved, and the measurement cost can be reduced while ensuring high-precision measurement.

Description

Technical Field

[0001] This application belongs to the field of gravity gradient measurement technology, and more specifically, relates to a gravity gradient differential vertical gravity gradient meter. Background Technology

[0002] The gravity gradiometer is a high-precision instrument used to measure the rate of change of the Earth's gravitational field in space, and it has important applications in fields such as geological resource exploration and space mapping.

[0003] Currently, common gravity gradiometers are typically based on differential acceleration measurement or superconducting technology. The former cancels common-mode noise through symmetrically distributed accelerometers, but requires extremely high matching accuracy and is technically complex. The latter uses superconducting quantum interference devices (SQUIDs) as its core technology, featuring low noise and high sensitivity, but its core components require cryogenic environments, limiting its technological development and practical applications. However, due to technological limitations or large instrument size, these types of gravity gradiometers have not yet moved beyond the laboratory environment for convenient field use. Therefore, existing gravity gradiometers still face the challenge of balancing high accuracy and portability, as well as insufficient environmental adaptability. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, this application aims to solve the problems of existing gravity gradiometers, such as the difficulty in achieving both high accuracy and portability, and insufficient environmental adaptability.

[0005] To achieve the above objectives, in a first aspect, this application provides a gravity-buoyancy differential vertical gravity gradiometer, comprising: Liquid container, float, connecting bracket, counterweight and measuring system; the float includes an upper part submerged, a buoy-like rod and a lower part completely submerged; The float is disposed inside the liquid container. One end of the connecting bracket is vertically fixed to the upper surface of the float rod. The other end of the connecting bracket is rigidly connected to the counterweight. The center of mass of the float and the center of mass of the counterweight are located on the same vertical line. The bottom of the liquid container is fixed. The liquid container is used to hold a liquid with a density greater than that of the float, so that the body of the float is suspended in the liquid and the rod part is submerged in the liquid. The measurement system is used to measure the depth change of the float after the gravity gradient meter moves from the first measurement position to the second measurement position, and to determine the vertical gravity gradient change information between the first measurement position and the second measurement position based on the depth change.

[0006] Optionally, the cross-sectional area of ​​the float rod is smaller than the cross-sectional area of ​​the float body.

[0007] Optionally, the body of the float is a hollow structure.

[0008] Optionally, the measurement system includes a displacement sensor and a calculation module connected in sequence; The displacement sensor is used to measure the displacement change of the counterweight in the vertical direction in order to obtain the depth change of the float in the liquid. The calculation module is used to determine the vertical gravity gradient change information between the first measurement position and the second measurement position based on the depth change.

[0009] Optionally, the displacement sensor may include, but is not limited to, a capacitive displacement sensor, a photoelectric displacement sensor, or an ultrasonic displacement sensor.

[0010] Secondly, this application provides a measurement method applied to any of the aforementioned gravity gradient differential vertical gravity meters, comprising: The depth change of the float is measured after the gravity gradient meter moves from the first measurement position to the second measurement position. Based on the depth change, the vertical gravity gradient change information between the first measurement position and the second measurement position is determined.

[0011] Optionally, determining the vertical gravity gradient change information between the first measurement position and the second measurement position based on the depth change includes: The mass of the counterweight in the gravity gradiometer, the height difference between the counterweight and the center of mass of the float, the cross-sectional area of ​​the float rod, and the density and volume of the liquid in the liquid container are obtained. By using the depth change, the mass of the counterweight, the height difference, the cross-sectional area, and the density and volume of the liquid, a vertical gravity gradient change analysis is performed to determine the vertical gravity gradient change information between the first measurement position and the second measurement position.

[0012] Optionally, the vertical gravity gradient change information is calculated using a preset vertical gravity gradient change calculation model; The preset vertical gravity gradient change calculation model is as follows: ; In the formula, This indicates the information regarding the change in the vertical gravity gradient. This represents the amount of depth change. This indicates the mass of the counterweight. Represents gravitational acceleration. This indicates the height difference. This represents the cross-sectional area. , These represent the density and volume of the liquid being contained, respectively.

[0013] Overall, the technical solutions conceived in this application have the following beneficial effects compared with the prior art: (1) The gravity gradient meter provided in this application is designed by using a liquid container, a float, a connecting bracket, a counterweight and a high-precision measurement system. The vertical gravity gradient measurement is transformed into a differential measurement of the buoyancy of the float and the gravity of the counterweight. The measurement system accurately measures the depth change of the float and quickly calculates the change of the vertical gravity gradient, which can effectively improve the accuracy and efficiency of the measurement. (2) The gravity gradient meter provided in this application consists of a probe and a measurement system with rigid connection. The structure is simple and reliable, and the instrument is small in size. It can greatly improve the portability of the instrument and reduce the measurement cost while ensuring high-precision measurement. It also improves the environmental adaptability of the gravity gradient meter and facilitates its portable use in field exploration. It has a wide range of application prospects. Attached Figure Description

[0014] Figure 1 This is one of the structural schematic diagrams of the gravity differential vertical gravity gradiometer provided in the embodiments of this application; Figure 2 This is the second schematic diagram of the structure of the gravity differential vertical gravity gradiometer provided in the embodiments of this application; Figure 3 This is a flowchart illustrating the measurement method of the gravity differential vertical gravity gradient meter provided in the embodiments of this application. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0016] The terms "first" and "second," etc., used in the specification and claims of this application are used to distinguish different objects, not to describe a specific order of objects. For example, "first measurement position" and "second measurement position," etc., are used to distinguish different measurement positions, not to describe a specific order of measurement positions.

[0017] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0018] The embodiments of this application are described below with reference to the accompanying drawings.

[0019] Figure 1 This is one of the structural schematic diagrams of the gravity differential vertical gravity gradiometer provided in the embodiments of this application, such as... Figure 1 As shown, it includes: Liquid container 1, float 2, connecting bracket 3, counterweight 4 and measuring system 5; the float includes a float rod 21 that is partially submerged above and resembles a buoy and a float body 22 that is completely submerged below; The float 2 is placed inside the liquid container 1. One end of the connecting bracket 3 is vertically fixed to the upper surface of the float rod 21, and the other end of the connecting bracket 3 is rigidly connected to the counterweight 5. The center of mass of the float 2 and the center of mass of the counterweight 4 are located on the same vertical line. The bottom of the liquid container 1 is fixed. The liquid container 1 is used to hold a liquid with a density greater than that of the float 2, so that the float body 22 of the float 2 is suspended in the liquid, the lower half of the float rod 21 is submerged in the liquid, and the upper half of the float rod 21 is exposed above the liquid surface. The measurement system 5 is used to measure the depth change of the float 2 after the gravity gradient meter moves from the first measurement position to the second measurement position, and to determine the vertical gravity gradient change information between the first measurement position and the second measurement position based on the depth change.

[0020] Specifically, the first measurement location and the second measurement location described in the embodiments of this application refer to two geographical locations where the gravitational fields may differ. To facilitate the explanation of the working principle of the gravity-buoyancy differential vertical gravity gradiometer provided in the embodiments of this application, in the following specific embodiment description, it can be assumed that the gravitational fields at the first measurement location and the second measurement location are different, and that there is a change in the vertical gravity gradient.

[0021] In the embodiments of this application, the liquid container is used to hold a liquid with a density greater than that of the float. The liquid density can be much greater than the float density, meaning the float density is much less than the liquid density, allowing the float to float in the liquid. By vertically fixing one end of the connecting bracket to the upper surface of the float's rod, and rigidly connecting the other end of the connecting bracket to the counterweight, the float and the counterweight can be fixedly connected as one unit. Thus, by selecting an appropriate counterweight, the lower part of the float can be completely submerged in the liquid, while part of the rod above the float is submerged in the liquid, and the other part is exposed above the liquid surface.

[0022] It should be noted that the shape and structure of the float can be a cube or other polyhedral structure, and this application does not make any specific limitation on this.

[0023] In the embodiments of this application, the center of mass of the float and the center of mass of the counterweight are located on the same vertical line, which ensures that the float always maintains displacement in the direction of gravity.

[0024] When the vertical gravity gradiometer is used at the first measurement position, the initial force equilibrium state causes the float to float at a certain position in the liquid. When the vertical gravity gradiometer is moved from the first measurement position to the second measurement position, the vertical gravity gradient will change due to the difference in the gravitational fields at the two measurement positions, and the float and counterweight in the instrument will move.

[0025] For example, when the vertical gravitational gradient increases, the original force balance will be broken. The counterweight will cause the float to sink and displace more liquid to obtain greater buoyancy, eventually reaching a new force balance. Conversely, when the vertical gravitational gradient decreases, the float will rise to achieve a new force balance.

[0026] Furthermore, in the embodiments of this application, after the vertical gravity gradient meter is moved from the first measurement position to the second measurement position, during the movement of the counterweight and the float, the measurement system can quickly and accurately measure the height change of the counterweight, which serves as the measurement probe, using internally preset high-precision sensors, such as capacitive displacement sensors or photoelectric displacement sensors. Since the counterweight and the float are fixedly connected, the height change of the counterweight reflects the depth change of the float.

[0027] Furthermore, the measurement system can use a pre-set calculation model to perform vertical gravity gradient change analysis and calculation using the depth change, thereby obtaining vertical gravity gradient change information between the first measurement position and the second measurement position.

[0028] Here, the pre-set calculation model can be obtained by moving the vertical gravity gradient meter from the first measurement position to the second measurement position and then performing differential measurement analysis on the buoyancy of the float and the gravity of the counterweight.

[0029] The differential vertical gravity gradiometer of this application uses a liquid container, a float, a connecting bracket, a counterweight, and a high-precision measurement system to design the gravity gradiometer. It transforms the measurement of vertical gravity gradient into a differential measurement of the buoyancy of the float and the gravity of the counterweight. The measurement system accurately measures the depth change of the float and quickly calculates the change of vertical gravity gradient, which can effectively improve the accuracy and efficiency of the measurement.

[0030] The gravity gradiometer of this application embodiment consists of a rigidly connected probe and a measurement system. It has a simple and reliable structure and a small instrument size. While ensuring high-precision measurement, it can greatly improve the portability of the instrument and reduce the measurement cost. It also improves the environmental adaptability of the gravity gradiometer, making it convenient for portable use in field exploration and has broad application prospects.

[0031] Based on the above embodiments, as an optional embodiment, the cross-sectional area of ​​the float rod is smaller than the cross-sectional area of ​​the float body.

[0032] Specifically, in the embodiments of this application, the float can be optimized to adopt a variable cross-section design, so that the cross-sectional area of ​​the float rod is smaller than the cross-sectional area of ​​the float body. For example, the float rod can be a thin rod with a cross-sectional area much smaller than that of the float body.

[0033] In this way, when the instrument is measuring, the entire body of the float below is submerged in the liquid, while the thinner rod above the float is partially submerged and partially exposed above the liquid surface. When the vertical gravitational gradient changes, causing a certain change in the volume of displaced liquid, the depth of the thin rod immersed in the liquid will change significantly due to its small cross-sectional area. This can improve the sensitivity of the overall measurement and enhance the accuracy of the instrument.

[0034] Based on the above embodiments, as an optional embodiment, the body of the float is a hollow structure.

[0035] Specifically, in the embodiments of this application, the body of the float can preferably be designed as a hollow structure. This allows the float to generate sufficient buoyancy to balance the weight of the counterweight, enabling the float to float in the liquid. When the instrument performs a measurement, the entire body of the float is submerged in the liquid, with a portion of the thinner rod at its upper end submerged and the other portion protruding above the liquid surface. When the vertical gravitational gradient changes, the change in the depth of the thinner rod immersed in the liquid becomes more significant and sensitive, thereby further improving the sensitivity of the overall measurement and enhancing the measurement accuracy of the instrument.

[0036] Figure 2 This is a second schematic diagram of the structure of the gravity differential vertical gravity gradiometer provided in the embodiments of this application, as shown below. Figure 2As shown, the measurement system 5 includes a displacement sensor 51 and a calculation module 52 connected in sequence; The displacement sensor 51 is used to measure the change in displacement of the counterweight in the vertical direction in order to obtain the change in depth of the float in the liquid. The calculation module 52 is used to determine the vertical gravity gradient change information between the first measurement position and the second measurement position based on the depth change.

[0037] Specifically, in the embodiments of this application, the measurement system may include a displacement sensor and a calculation module connected in sequence. The displacement sensor may be a high-precision sensor used to accurately measure the vertical displacement change of the counterweight, thereby indirectly measuring the depth change of the float in the liquid.

[0038] Since the float and counterweight are fixedly connected as a single unit via connectors, the change in vertical displacement of the counterweight is exactly the same as the change in the float's suspended depth in the liquid. Therefore, the problem of measuring the float's depth change can be transformed into the problem of measuring the counterweight's displacement change.

[0039] Furthermore, high-precision displacement sensors can accurately measure the vertical displacement of the counterweight, thereby indirectly obtaining high-precision results of the float depth change.

[0040] Based on the above embodiments, as an optional embodiment, the displacement sensor includes, but is not limited to, a capacitive displacement sensor, a photoelectric displacement sensor, or an ultrasonic displacement sensor.

[0041] The vertical gravity gradient meter of this application uses a displacement sensor for measuring the displacement of the counterweight. This sensor can be a capacitive displacement sensor, a photoelectric displacement sensor, an ultrasonic displacement sensor, or other displacement sensors that can achieve the same measurement effect. This can improve the diversity and selectivity of the instrument design.

[0042] Furthermore, the calculation module can obtain the depth change of the float in the liquid measured by the displacement sensor, and use this depth change information to perform gravity gradient change analysis according to the preset calculation model to obtain the vertical gravity gradient change information between the first measurement position and the second measurement position.

[0043] The vertical gravity gradient meter of this application, by using a displacement sensor and a calculation module to build a measurement system, converts the change in depth of the float in the liquid into the change in displacement of the counterweight in the vertical direction. This makes it easier to design and measure the internal components of the instrument, and helps to further reduce the manufacturing cost of the instrument.

[0044] The measurement method of the buoyancy differential vertical gravity gradiometer provided in this application is described below. The measurement method described below can be referred to in correspondence with the buoyancy differential vertical gravity gradiometer described above.

[0045] Figure 3 This is a flowchart illustrating the measurement method of the gravity differential vertical gravity gradiometer provided in this application embodiment, which can be applied to any of the aforementioned gravity differential vertical gravity gradiometers, such as... Figure 3 As shown, the method includes: Step S1: Measure the change in the depth of the float after the gravity gradient meter moves from the first measurement position to the second measurement position; Step S2: Based on the depth change, determine the vertical gravity gradient change information between the first measurement position and the second measurement position.

[0046] Specifically, in the embodiments of this application, when the gravity differential vertical gravity gradient meter is in the first measurement position, the float is simultaneously subjected to the downward gravity from the counterweight and the upward buoyancy of the liquid, achieving a state of force balance. Specifically, selecting an appropriate counterweight allows the float's body to be completely submerged in the liquid, while the lower half of the float rod is submerged and the upper half of the float rod protrudes above the liquid surface.

[0047] When the differential vertical gravity gradient meter moves from the first measurement position to the second measurement position, if the vertical gravity gradient increases, the original force balance is broken. The counterweight causes the float to sink and displace more liquid to obtain greater buoyancy, eventually reaching a new force balance. Conversely, when the vertical gravity gradient decreases, the float rises to achieve a new force balance. The change in buoyancy corresponding to the newly displaced liquid is the same as the change in gravity caused by the vertical gravity gradient, thus bringing the system to a new force balance. The volume of the newly displaced liquid is equal to the product of the cross-sectional area of ​​the upper rod of the float and the change in depth. By measuring the change in the depth of the float, the change in the vertical gravity gradient can be calculated.

[0048] It is understood that detailed implementation methods for each of the above steps can be found in the description of the aforementioned vertical gravity gradiometer embodiment, and will not be repeated here.

[0049] It should also be understood that the above method can be applied to the vertical gravity gradiometer in the above embodiments. The implementation principle and technical effect of the method are similar to those described in the above instrument structure and measurement system embodiments. The corresponding process in the above instrument embodiments can be referred to, and will not be repeated here.

[0050] The measurement method of the differential vertical gravity gradiometer according to the embodiments of this application, by designing the gravity gradiometer with a liquid container, float, connecting bracket, counterweight and high-precision measurement system, provides a buoyancy environment that makes the movement of the moving carrier in the measurement platform more sensitive and stable. At the same time, by converting the vertical gravity gradient measurement into a differential measurement of the buoyancy of the float and the gravity of the counterweight, the measurement system accurately measures the depth change of the float and quickly calculates the change of the vertical gravity gradient, which can effectively improve the accuracy and efficiency of the measurement.

[0051] The measurement method of the gravity gradiometer of the present application embodiment consists of a probe and a measurement system with rigid connection. The structure is simple and reliable, and the instrument is small in size. It can greatly improve the portability of the instrument and reduce the measurement cost while ensuring high-precision measurement. It also improves the environmental adaptability of the gravity gradiometer, making it convenient for portable use in field exploration. It has a wide range of application prospects.

[0052] Based on the above embodiments, as an optional embodiment, step S2, determining the vertical gravity gradient change information between the first measurement position and the second measurement position based on the depth change, includes: The mass of the counterweight in the gravity gradiometer, the height difference between the counterweight and the center of mass of the float, the cross-sectional area of ​​the float rod, and the density and volume of the liquid in the liquid container are obtained. Vertical gravity gradient variation analysis is performed using depth change, counterweight mass, height difference, cross-sectional area, and density and volume of the liquid to determine the vertical gravity gradient variation information between the first and second measurement positions.

[0053] Specifically, in the embodiments of this application, a calculation model for the change of vertical gravity gradient can be obtained by performing differential measurement analysis on the buoyancy and gravity of the float after the vertical gravity gradient meter is moved from the first measurement position to the second measurement position.

[0054] Based on the above embodiments, as an optional embodiment, the vertical gravity gradient change information is calculated by a preset vertical gravity gradient change calculation model; The preset calculation model for vertical gravity gradient change is as follows:

[0055] In the formula, This indicates information about the vertical gravitational gradient. This indicates the change in the depth of the float. Indicates the mass of the counterweight. Represents gravitational acceleration. This indicates the height difference between the counterweight and the float's center of mass. This represents the cross-sectional area of ​​the float rod. , These represent the density and volume of the liquid being held, respectively.

[0056] Specifically, for ease of understanding, the measurement principle of the vertical gravity gradient meter provided in this application is described below.

[0057] Assuming the mass of the counterweight is m and the acceleration due to gravity is g, then the gravitational force acting on it is... The height difference between the counterweight and the center of mass of the buoy is H, and the vertical gravitational gradient is... Then there is the difference in gravitational acceleration from one location to another. The volume of the float immersed in the liquid is V, and the density of the liquid is ρ. Then the buoyant force acting on the float is... .

[0058] If the vertical gravity gradient at the second measurement location is This disrupts the force balance within the instrument at the first measurement position. To achieve a new force balance, the float freely rises or sinks to adjust the buoyancy, with the depth change being... Because the float is designed this way, the depth change here occurs entirely within the thinner section of the upper part of the float, which has a smaller cross-section. Assuming the cross-sectional area of ​​the float rod is S, the volume change of the float immersed in the liquid... The buoyancy of the float Relative vertical gravitational gradient, i.e., information on changes in the vertical gravitational gradient. By performing force equilibrium analysis and substituting the above equations into... and This allows us to obtain a pre-defined calculation model for the vertical gravity gradient change, namely:

[0059] Based on the above model expression, it can be seen that the change in the depth of the float after the vertical gravity gradient meter moves from the first measurement position to the second measurement position is obtained through displacement detection. This allows for the calculation of the vertical gravity gradient change between the first and second measurement positions. .

[0060] The method in this application embodiment, based on the vertical gravity gradiometer structure designed in this application, transforms the vertical gravity gradient measurement into a differential measurement of the buoyancy of the float and the gravity of the counterweight. By analyzing the force balance of the front and rear floats, a calculation model for the change of vertical gravity gradient is obtained, which can ensure the accuracy and effectiveness of the vertical gravity gradiometer measurement results.

[0061] Furthermore, in the embodiments of this application, the pre-designed counterweight mass m, the height difference H between the counterweight and the center of mass of the float, and the cross-sectional area of ​​the float rod are obtained in the gravity gradiometer. and the density of the liquid contained in the liquid container and volume ; Furthermore, the depth change measured using the aforementioned high-precision displacement sensor Combined with the preset counterweight mass m, the height difference H between the counterweight and the center of mass of the float, and the cross-sectional area of ​​the float rod... and the density of the liquid contained in the liquid container and volume To perform vertical gravity gradient variation analysis, the above parameters are substituted into a preset vertical gravity gradient variation calculation model, and the vertical gravity gradient variation information between the first measurement position and the second measurement position can be calculated.

[0062] The method in this application embodiment utilizes a preset vertical gravity gradient change calculation model, combined with the depth change measured by a high-precision displacement sensor, and the pre-designed counterweight mass, the height difference between the counterweight and the center of mass of the float, the cross-sectional area of ​​the float rod, and the density and volume of the liquid in the liquid container to perform vertical gravity gradient change analysis. This method can effectively calculate the vertical gravity gradient change information between the first measurement position and the second measurement position, ensuring the high measurement accuracy and efficiency of the gravity gradiometer.

[0063] The method steps in this application embodiment can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can reside in a custom integrated circuit (ASIC).

[0064] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0065] It is understood that the various numerical designations used in the embodiments of this application are merely for the convenience of description and are not intended to limit the scope of the embodiments of this application.

[0066] It should be understood that expressions such as “comprising” 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 “comprising” and / or “having” are to be interpreted as indicating a particular characteristic, number, operation, constituent element, component, or combination thereof, but not to exclude the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0067] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. "Fixed connection" refers to a connection where the relative positional relationship remains unchanged after connection. "Rotary connection" refers to a connection where the components can rotate relative to each other after connection. "Sliding connection" refers to a connection where the components can slide relative to each other after connection. The directional terms mentioned in the embodiments of this application, such as "top," "bottom," "inner," "outer," "left," and "right," are only for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of this application, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0068] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A gravity gradient meter with differential gravity, characterized in that, include: Liquid container, float, connecting bracket, counterweight and measuring system; the float includes an upper part submerged, a float rod similar to a buoy and a lower part completely submerged; The float is disposed inside the liquid container, one end of the connecting bracket is vertically fixed to the upper surface of the rod, the other end of the connecting bracket is rigidly connected to the counterweight, and the center of mass of the float and the center of mass of the counterweight are located on the same vertical line. The bottom of the liquid container is fixed. The liquid container is used to hold a liquid with a density greater than that of the float, so that the body of the float is suspended in the liquid, the lower half of the float rod is submerged in the liquid, and the upper half of the float rod is exposed above the liquid surface. The measurement system is used to measure the depth change of the float after the gravity gradient meter moves from a first measurement position to a second measurement position, and to determine the vertical gravity gradient change information between the first measurement position and the second measurement position based on the depth change.

2. The gravity gradient meter with differential gravity according to claim 1, characterized in that, The cross-sectional area of ​​the float rod is smaller than the cross-sectional area of ​​the float body.

3. The gravity differential vertical gravity gradient instrument according to claim 2, characterized in that, The body of the float is a hollow structure.

4. The gravity differential vertical gravity gradient instrument according to any one of claims 1-3, characterized in that, The measurement system includes a displacement sensor and a calculation module connected in sequence; The displacement sensor is used to measure the displacement change of the counterweight in the vertical direction in order to obtain the depth change of the float in the liquid. The calculation module is used to determine the vertical gravity gradient change information between the first measurement position and the second measurement position based on the depth change.

5. The gravity gradient meter with differential gravity according to claim 4, characterized in that, The displacement sensor includes, but is not limited to, a capacitive displacement sensor, a photoelectric displacement sensor, or an ultrasonic displacement sensor.

6. A measurement method applied to a gravity differential vertical gravity gradient meter as described in any one of claims 1-5, characterized in that, include: The depth change of the float is measured after the gravity gradient meter moves from the first measurement position to the second measurement position. Based on the depth change, the vertical gravity gradient change information between the first measurement position and the second measurement position is determined.

7. The measurement method according to claim 6, characterized in that, The step of determining the vertical gravity gradient change information between the first measurement position and the second measurement position based on the depth change includes: The mass of the counterweight in the gravity gradiometer, the height difference between the counterweight and the center of mass of the float, the cross-sectional area of ​​the float rod, and the density and volume of the liquid in the liquid container are obtained. By using the depth change, the mass of the counterweight, the height difference, the cross-sectional area, and the density and volume of the liquid, a vertical gravity gradient change analysis is performed to determine the vertical gravity gradient change information between the first measurement position and the second measurement position.

8. The measurement method according to claim 7, characterized in that, The vertical gravity gradient change information is calculated using a preset vertical gravity gradient change calculation model; The preset vertical gravity gradient change calculation model is as follows: ; In the formula, This indicates the information regarding the change in the vertical gravity gradient. This represents the amount of depth change. This indicates the mass of the counterweight. Represents gravitational acceleration. This indicates the height difference. This represents the cross-sectional area. , These represent the density and volume of the liquid being contained, respectively.

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