A gravity vector measurement method, system, medium, device and terminal

Abstract

The present invention belongs to the field of gravity measurement technology, and discloses a gravity vector measurement method, system, medium, equipment and terminal. According to the reference selection principle, the gravity scalar data is two-dimensionally decomposed along the direction of the earth's rotation axis, and the gravity scalar data is the composite quantity of the three-dimensional measurement results of the gravimeter; through the two-dimensional decomposition, a part of the components is the projection of gravity in the direction of the earth's rotation axis, and the remaining components are determined according to the vector triangle decomposition. The gravity vector measurement method of the present invention uses the rotation axis direction as the reference for gravity projection, and the rotation axis direction is a physical quantity with physical measurability. The present invention has a unified reference, which is conducive to the comparison and monitoring of gravity information at different locations. However, in the local geographic coordinate system, it is also necessary to consider the problem of attitude accuracy interfering with the measurement of gravity deviation. From the observable dimension of the reference vector, the present invention increases the signal strength in this direction, while reducing the noise intensity in this direction, thereby improving the signal-to-noise ratio.

Description

Technical Field

[0001] The present invention belongs to the field of gravity measurement technology, and in particular relates to a gravity vector measurement method, system, medium, equipment and terminal. Background Art

[0002] The gravity field reflects the inherent and essential properties of the Earth and is an important research direction in geophysics. Its military value is particularly prominent: (1) High-precision Earth gravity field is an important basic data for the construction of the national comprehensive PNT (positioning, navigation, and timing) system and the construction of gravity matching fields in strategic value areas; (2) High-precision gravity field is an important support for improving weapon guidance, inertial navigation, underwater matching navigation, etc.; (3) High-precision gravity field can provide a covert detection method for submarine underwater target detection.

[0003] Current gravity measuring instruments can be categorized as platform-based and strapdown-based, depending on whether a stable platform is required. Platform-based gravimeters utilize a stable platform system that isolates the carrier from motion and vibration, typically using the geoid as a physical reference. They can generally only measure gravity. Strapdown gravimeters simulate platform rotation through mathematical calculations, accurately measuring the resultant acceleration in real time. These instruments then deduct the carrier's motion acceleration to obtain the gravity value. These instruments place high demands on the dynamic range of the gravity sensor and struggle to precisely correct for complex dynamic effects.

[0004] However, in the current mainstream methods, both platform-type gravimeters and strapdown gravimeters use the local geographic coordinate system as the reference system for the gravity vector, with the vertical deviation from the celestial axis of the geographic coordinate system and gravity anomaly as specific indicators. Traditional gravity vector measurement has the following main problems:

[0005] 1. Inertial elements cannot observe the local geographical system from a mechanistic perspective.

[0006] The local geographic system is a rectangular coordinate system defined on a reference ellipsoid with its three axes pointing to the "northeast sky". The geoid is affected by the topography and density of the earth's surface and is a smooth, slightly undulating, closed, irregular surface, such as Figure 5 The gravimeter can only obtain an approximate geographic coordinate system through initial alignment using its own inertial sensors, which meets the requirements of navigation applications but does not meet the requirements of gravity disturbance measurement.

[0007] 2. In principle, the "horizontal" and "vertical" gravity decomposition methods cannot increase the observation dimension of gravity.

[0008] Using the local geographic coordinate system as the reference frame, the gravity vector is largely decomposed into the vertical component. The horizontal component contains very little gravity information and is easily lost in the horizontal measurement noise. Currently, the attitude accuracy of most gravity-stabilized platforms is no better than 1", and a 1" attitude error can cause 6-8 mGal of horizontal gravity component noise, making this decomposition method inherently only one-dimensional.

[0009] This viewpoint can be easily proved theoretically: Take g = 10m / s 2 , based on the attitude error of 1", the measurement error of the horizontal component of gravity is:

[0010] δg 水平 =g·sin(1”)=5mGal (1)

[0011] Equation (1) shows that if there is an attitude error of 1", even if the horizontal component of gravity is measured by a Bell XI accelerometer with a resolution of 0.1 mGal, its reliability will not be higher than 5 mGal. The amount of gravity information decomposed in the horizontal direction is too small and is submerged in the measurement noise caused by the attitude error.

[0012] 3. Plumb line deviation and normal gravity are not suitable as measurement indicators of gravity vector.

[0013] Methods for measuring vertical deviation primarily include astro-geodesy, GNSS / leveling, gravity perturbation calculation, and gravity gradient measurement. However, these methods are difficult to measure and have limited accuracy, making it difficult to accurately determine vertical deviation. During navigation, vertical deviation is inevitably incorporated into attitude calculations. Gravity is both an input and a measurement, leading to coupling issues between gravity and attitude in the solution. Summary of the Invention

[0014] In response to the problems existing in the prior art, the present invention provides a gravity vector measurement method, system, medium, device and terminal, and in particular relates to a gravity vector measurement method, system, medium, device and terminal based on earth axis projection.

[0015] The present invention is implemented as follows: a gravity vector measurement method, the gravity vector measurement method comprising:

[0016] According to the benchmark selection principle, the gravity scalar data is decomposed two-dimensionally along the direction of the Earth's rotation axis from the perspective of improving the signal-to-noise ratio of the gravity component measurement data. The gravity scalar data is the composite of the three-dimensional measurement results of the gravimeter, denoted as g;

[0017] Through two-dimensional decomposition, one component is the projection of gravity toward the direction of the earth's rotation axis, denoted as g ω , the remaining components are determined by vector triangle decomposition and are denoted as grest .

[0018] Furthermore, the benchmark selection principles include benchmark measurability, stability and benchmark vector observability.

[0019] Furthermore, the gravity vector measurement method further includes:

[0020] In the gravity measurement environment, the inertial measurement component determines the direction of the Earth's rotation axis. The projection measurement algorithm is based on the two-dimensional decomposition of the gravity vector of the Earth's axis to obtain the projection relationship of the gravity vector under the load system to the Earth's axis, thereby realizing the two-dimensional representation of the gravity vector based on the Earth's axis.

[0021] Furthermore, the gravity vector measurement method includes the following steps:

[0022] Step 1: The gravity sensitive mechanism measures the gravity data value g in real time;

[0023] Step 2: The strapdown inertial measurement unit detects the acceleration and angular velocity in the inertial frame to determine the direction of the Earth's rotation axis.

[0024] Step 3: Decompose the gravity value measured in step 1 toward the direction of the earth's rotation axis to obtain the decomposed gravity value g ω and g rest ;

[0025] Step 4: According to the decomposed gravity value g ω and g rest Perform two-dimensional gravity matching navigation.

[0026] Another object of the present invention is to provide a gravity vector measurement system using the gravity vector measurement method. The gravity vector measurement system consists of four parts: an inertial stabilization platform, a strapdown gravimeter, a control system chassis, and a data acquisition and processing module.

[0027] The inertial stabilization platform includes an inertial measurement unit (IMU) and a platform control system, which is used to provide a stable measurement environment for the strapdown gravimeter.

[0028] The strapdown gravimeter includes a constant temperature box, a strapdown inertial measurement unit and a gravity sensitive mechanism;

[0029] The high-precision three-axis gyroscope installed in the strapdown gravimeter is used to sense the earth's axis and project the three-axis accelerometer measurement value onto the earth's axis. The core is the gravity vector decomposition algorithm;

[0030] The control system chassis is connected to the strapdown gravimeter and the inertial stabilization platform, and is used to control the inertial stabilization platform and the temperature of the strapdown gravimeter;

[0031] The data acquisition and processing module is connected to the control system chassis and includes a projection measurement algorithm, a driver, a development environment and a data interface.

[0032] Furthermore, the inertial stabilization platform is also used to track the geoid, and the stability of the geoid is monitored by a level device.

[0033] Furthermore, the strapdown inertial measurement unit is the core of the strapdown gravimeter;

[0034] Bell XI accelerometer and Honeywell QA3000 quartz flexure accelerometer were selected.

[0035] Another object of the present invention is to provide a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the following steps:

[0036] According to the benchmark selection principle, the gravity scalar data is decomposed two-dimensionally along the direction of the Earth's rotation axis from the perspective of improving the signal-to-noise ratio of the gravity component measurement data. The gravity scalar data is the composite of the three-dimensional measurement results of the gravimeter, denoted as g;

[0037] Through two-dimensional decomposition, one component is the projection of gravity toward the direction of the earth's rotation axis, denoted as g ω , the remaining components are determined by vector triangle decomposition and are denoted as g rest .

[0038] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor performs the following steps:

[0039] According to the benchmark selection principle, the gravity scalar data is decomposed two-dimensionally along the direction of the Earth's rotation axis from the perspective of improving the signal-to-noise ratio of the gravity component measurement data. The gravity scalar data is the composite of the three-dimensional measurement results of the gravimeter, denoted as g;

[0040] Through two-dimensional decomposition, one component is the projection of gravity toward the direction of the earth's rotation axis, denoted as g ω , the remaining components are determined by vector triangle decomposition and are denoted as g rest .

[0041] Another object of the present invention is to provide an information data processing terminal, which is used to implement the gravity vector measurement system.

[0042] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are analyzed from the following aspects:

[0043] First, in view of the technical problems existing in the above-mentioned prior art and the difficulty of solving these problems, this paper closely combines the technical solutions to be protected by the present invention and the results and data during the research and development process, and analyzes in detail and in depth how the technical solutions of the present invention solve the technical problems and some creative technical effects brought about by solving the problems. The specific description is as follows:

[0044] (1) The method proposed in the present invention can accurately establish the mathematical conversion relationship between the carrier system and the reference system, improve the measurability of the reference, and thus improve the credibility of the gravity measurement value. The Earth's rotation axis is a physical quantity with physical measurability. The gravity projection is performed based on the direction of the rotation axis, and the projection relationship between the reference and the carrier system can be accurately obtained. In the traditional projection method based on the local geographic system, the local geographic system is an ideal mathematical coordinate system, which is essentially a statistical quantity and cannot be directly measured. This will inevitably lead to conversion errors between the carrier system and the reference system.

[0045] (2) The method proposed in this invention has stronger physical significance and is more suitable for two-dimensional characterization of measured gravity. The rotation axis is the inherent axis of the Earth. At any location on the Earth, the rotation axis has a stable orientation and a unified reference, which facilitates the comparison and monitoring of gravity information at different locations. In traditional methods, however, the error caused by attitude measurement must also be considered, which affects the accuracy of the two-dimensional decomposition of gravity.

[0046] (3) The method proposed in this invention realizes the advancement of gravity observation from one dimension to two dimensions, and improves the observability of gravity vector. By projecting gravity onto the Earth's rotation axis, except for the equator and the polar regions, all other regions can ensure that there is sufficient gravity information in the direction of the Earth's axis and the residual component. Take g = 10m / s 2 Gravity is decomposed near a latitude of 45°, with the vertical deviation recorded as 3". The attitude error is random noise with an amplitude of 1". Equation (2) is the signal-to-noise ratio in the horizontal direction of the technology proposed by the present invention, and Equation (3) is the signal-to-noise ratio in the horizontal direction based on the traditional local geographic system. It can be seen that the technical solution of the present invention not only increases the signal strength in the horizontal direction, but also reduces the noise intensity in this direction. The signal-to-noise ratio is improved from approximately 12dB of the traditional method to approximately 106dB of the present invention.

[0047]

[0048]

[0049] Second, considering the technical solution as a whole or from the perspective of the product, the technical effects and advantages of the technical solution to be protected by the present invention are described in detail as follows:

[0050] The gravity vector measurement method provided by the present invention improves the measurability of the gravity projection benchmark, facilitates the comparison and monitoring of gravity information at different locations, increases the signal strength in that direction, and simultaneously reduces the noise intensity in that direction, thereby improving the signal-to-noise ratio, achieving the advancement of gravity observation from one dimension to two dimensions, and improving the observability of the gravity vector.

[0051] Third, as auxiliary evidence for the inventiveness of the claims of the present invention, it is also reflected in the following important aspects:

[0052] The technical solution of this invention fills a technological gap in the industry both domestically and internationally. High-precision vector gravity fields are a major national strategic resource, and their research is of great significance. However, existing gravity reference maps are scalar gravity maps, with low accuracy and very limited utility. The technical solution proposed in this invention improves gravity measurement accuracy while providing a two-dimensional representation of gravity vectors. This allows the gravity reference map to be constructed as a two-dimensional vector field map, thus filling the gap in the Earth's vector gravity field reference map.

[0053] Does the technical solution of the present invention solve a technical problem that people have long desired but have never been able to solve: high-precision dynamic gravity vector measurement has always been a difficult problem in the field of geodesy. The traditional decomposition method of gravity into "vertical" and "horizontal" components causes most of the gravity vector information to be concentrated in the vertical direction. The gravity information contained in the horizontal component is very small and easily submerged in the measurement noise in the horizontal direction. As a result, this decomposition method is essentially still a scalar measurement of gravity in the vertical direction. The technical solution proposed by the present invention decomposes gravity along the Earth's rotation axis, ensuring that gravity has sufficient information in two dimensions, advancing gravity from one-dimensional to two-dimensional observation, and improving the observability of the gravity vector. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0055] Figure 1 is a flow chart of a gravity vector measurement method provided by an embodiment of the present invention;

[0056] Figure 2 This is an overall block diagram of a gravity vector measurement system provided by an embodiment of the present invention;

[0057] Figure 3 is a schematic diagram of two-dimensional gravity decomposition provided by an embodiment of the present invention;

[0058] Figure 4 is a schematic diagram comparing the gravity matching effects provided by an embodiment of the present invention;

[0059] Figure 5 It is a diagram of the earth's geoid and reference ellipsoid provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0061] In order to solve the problems existing in the prior art, the present invention provides a gravity vector measurement method, system, medium, device and terminal. The present invention is described in detail below with reference to the accompanying drawings.

[0062] 1. Explanatory Examples In order to enable those skilled in the art to fully understand how to implement the present invention, this section provides an illustrative example that expands upon the technical solutions of the claims.

[0063] like Figure 1 As shown, the gravity vector measurement method provided by the embodiment of the present invention includes the following steps:

[0064] S101, the gravity sensitive mechanism measures the gravity data value g in real time;

[0065] S102, the strapdown inertial measurement unit detects the acceleration and angular velocity in the sensitive inertial frame to determine the direction of the Earth's rotation axis;

[0066] S103, decompose the gravity value measured in S101 toward the direction of the earth's rotation axis to obtain the decomposed gravity value g ω and g rest ;

[0067] S104, according to the decomposed gravity value g ω and g rest Perform two-dimensional gravity matching navigation.

[0068] like Figure 2 As shown, the gravity vector measurement system provided by the embodiment of the present invention consists of four parts: an inertial stabilization platform, a strapdown gravimeter, a control system chassis, and a data acquisition and processing module.

[0069] Among them, the inertial stabilization platform, including the inertial measurement unit IMU and the platform control system, is used to provide a stable measurement environment for the strapdown gravimeter;

[0070] Strapdown gravimeter, including a constant temperature chamber, a strapdown inertial measurement unit and a gravity-sensitive mechanism;

[0071] The high-precision three-axis gyroscope installed in the strapdown gravimeter is used to sense the earth's axis and project the three-axis accelerometer measurement value onto the earth's axis. The core is the gravity vector decomposition algorithm;

[0072] The control system chassis is connected to the strapdown gravimeter and the inertial stabilization platform to realize the control of the inertial stabilization platform and the temperature control of the strapdown gravimeter;

[0073] The data acquisition and processing module is connected to the control system chassis and includes projection measurement algorithms, drivers, development environment and data interface.

[0074] The technical solution of the present invention is further described below with reference to specific embodiments.

[0075] Currently, based on the local geographic system, the core problem is that gravity information is decomposed into gravity vectors according to the local geographic system. Most gravity information is decomposed into vertical components, and only a very small amount of gravity information is decomposed into horizontal components. As a result, the small amount of horizontal component information is submerged in the measurement noise caused by measurement noise and attitude error, making the observation dimension of the gravity vector still a one-dimensional scalar.

[0076] Based on this, the following datum selection principles are proposed for the selection of gravity vector datums:

[0077] 1. The selected benchmark should be measurable

[0078] Mathematically, if measurement errors are not considered, gravity can be represented using any coordinate system as a reference. This is especially true for matching applications, where accurate measurement of gravity, as an inherent property of the Earth, is crucial. Therefore, based on the sensor's performance characteristics, a coordinate system with high accuracy should be selected, ensuring the accurate determination of the attitude transformation matrix between the reference and measurement systems.

[0079] 2. The selected benchmark should have good stability

[0080] The direct data measured by a gravimeter on a moving base is the gravity vector under the carrier. However, the carrier is in complex, time-varying, and unpredictable motion, which is not conducive to monitoring and comparing the gravity vector. To represent the gravity vector at different locations, it is necessary to represent the gravity vector in a known, stable reference frame using an attitude rotation matrix. Therefore, the selected reference should have stability characteristics.

[0081] 3. The selected benchmark should consider vector observability

[0082] Gravity is vector data, so the distribution of valid information should be carefully considered when selecting a benchmark. Measurement noise is inherent in all measurements, so the gravity information should be decomposed as evenly as possible within the selected benchmark to avoid the problem of too little gravity information in a particular component, resulting in a low signal-to-noise ratio. When gravity is decomposed within the selected benchmark, if a component has some physical significance and can be observed through other means, it will be beneficial for gravity accuracy assessment and gravity anomaly monitoring.

[0083] According to the above-mentioned principle of selecting benchmarks, it is proposed to decompose the gravity scalar data into two dimensions along the direction of the Earth's rotation axis from the perspective of improving the signal-to-noise ratio of the gravity component measurement data, such as Figure 3 As shown, the gravity scalar data is the composite of the three-dimensional measurement results of the gravimeter, denoted as g. Through two-dimensional decomposition, one component is the projection of gravity toward the direction of the earth's rotation axis, denoted as g. ω , the remaining components are determined by vector triangle decomposition and are denoted as g rest .

[0084] like Figure 2 As shown in the figure, the implementation of the gravity vector measurement method based on the earth axis projection mainly consists of four parts: a stable platform, a strapdown inertial component, a control chassis and a measurement algorithm.

[0085] "Inertial stabilization platform": The role of the platform is to provide a stable measurement environment for the gravimeter. From the perspective of stability, the platform should track the geoid, which can be monitored for stability by equipment such as a level to avoid various unstable factors that may cause reliability problems with a single benchmark.

[0086] Strapdown Gravimeter: The strapdown inertial measurement unit (IMU) is the core of the gravimeter. It uses Bell XI accelerometers and Honeywell QA3000 quartz flexure accelerometers. The gravimeter is equipped with a high-precision triaxial gyroscope to sense the Earth's axis and project triaxial accelerometer measurements onto the Earth's axis. The core of the gravimeter is the gravity vector decomposition algorithm.

[0087] "Projection measurement algorithm": In the gravity measurement environment, the inertial measurement component can only determine the direction of the Earth's rotation axis. The algorithm focuses on the "two-dimensional decomposition of the gravity vector based on the Earth's axis" and aims to obtain the projection relationship of the gravity vector under the carrier system to the Earth's axis, thereby realizing the two-dimensional representation of the gravity vector based on the Earth's axis.

[0088] Step 1: The gravity sensitive mechanism measures the gravity data value g in real time.

[0089] Step 2: The strapdown inertial measurement unit (SIMU) senses the acceleration and angular velocity in the inertial frame and determines the direction of the Earth's rotation axis.

[0090] Step 3: Decompose the gravity value measured in step 1 toward the direction of the Earth's rotation axis to obtain the decomposed gravity value g ωand g rest .

[0091] Step 4: According to the decomposed gravity value g ω and g rest Perform two-dimensional gravity matching navigation.

[0092] The present invention proposes the advantages of decomposing the gravity measurement vector under the carrier system toward the Earth's rotation axis:

[0093] ① From the perspective of benchmark measurability, gravity projection is performed based on the direction of the rotation axis. The direction of the rotation axis is a physical quantity and is physically measurable, while the local geographic system is an ideal mathematical coordinate system, which is essentially a statistical quantity and cannot be directly measured.

[0094] ② From the perspective of benchmark stability, gravity is an inherent property of the Earth, and the rotation axis is the Earth's inherent axis. At any location on the Earth, the rotation axis points stably and the benchmark is unified, which is conducive to the comparison and monitoring of gravity information at different locations. When using the local geographic coordinate system as the benchmark, the impact of attitude measurement errors on gravity measurements must also be considered.

[0095] ③ From the observable dimension of the reference vector, compared with the "vertical" and "horizontal" decomposition methods, projecting gravity onto the earth's axis can ensure that all regions except the equator and the polar regions have sufficient gravity information in the direction of the earth's axis and the residual component. Take g = 10m / s 2 Gravity is decomposed near a latitude of 45°, with the vertical deviation recorded as 3". The attitude error is random noise with an amplitude of 1". Equation (4) is the signal-to-noise ratio in the horizontal direction of the technology proposed by the present invention, and Equation (5) is the signal-to-noise ratio in the horizontal direction based on the traditional local geographic system. It can be seen that the technical solution of the present invention not only increases the signal strength in the horizontal direction, but also reduces the noise intensity in this direction. The signal-to-noise ratio is improved from approximately 12dB of the traditional method to approximately 106dB of the present invention.

[0096]

[0097]

[0098] 2. Application Examples: In order to demonstrate the creativity and technical value of the technical solution of the present invention, this section provides application examples of the claimed technical solution on specific products or related technologies.

[0099] Gravity is an inherent property of the Earth. Traditional gravity vector measurement methods have little information about the horizontal component, which is easily lost in measurement noise, resulting in poor observability of the gravity vector. The technical solution of the present invention projects gravity along the Earth's rotation axis, ensuring sufficient gravity information in both the rotation axis and the direction perpendicular to the rotation axis. This improves the signal-to-noise ratio of gravity measurements and truly achieves a two-dimensional representation of the gravity vector. The technical value of the invention is particularly outstanding. The technical solution of the present invention includes, but is not limited to, the following application examples:

[0100] 1. The present invention can be applied to construct a two-dimensional earth gravity vector background field.

[0101] Gravity varies across the Earth's surface, possessing distinct local characteristics that reflect the physical properties and structure of objects at their locations. Gravity matching navigation can be achieved by matching gravity parameters. However, traditional gravity background fields are all scalar gravity background fields. Gravity matching algorithms achieve gravity matching navigation by exploring or improving search and matching strategies. However, using only the gravity magnitude parameter for matching navigation is not very effective in practice. Furthermore, due to limitations in sensor accuracy, feature separability is also limited. Using a two-dimensional vector representation of gravity projected onto the rotation axis to construct a gravity vector background field, and then matching using two-dimensional gravity measurements, this increases the feature dimension and inevitably improves matching results.

[0102] 2. The present invention can be applied to geological exploration.

[0103] Gravity can reflect geophysical characteristics and structures. The technical solution of the present invention projects gravity toward the direction of the Earth's rotation axis. By comparing the two-dimensional gravity vector measurement data of the gravimeter with the satellite gravity measurement data, it is beneficial to extract subtle changes in gravity and improve the efficiency of geological exploration.

[0104] 3. The present invention can be applied to any application field using gravity scalar data.

[0105] The technical solution of the present invention realizes the two-dimensional measurement of the gravity vector and realizes the normalization of global gravity through the rotation axis. The rotation axis can be used as a unified reference benchmark for global gravity, facilitating the comparison of gravity differences between different locations, and can be applied to any field currently using gravity scalar data.

[0106] 3. Evidence of the effects of the embodiments: The embodiments of the present invention have achieved some positive effects during the development or use process, and indeed have great advantages over the existing technology. The following content describes them with reference to the data, charts, etc. of the experimental process.

[0107] The effects of traditional gravity measurement technology and the gravity vector measurement technology based on earth axis projection proposed in this invention are simulated and analyzed using the ICCP gravity matching algorithm. Figure 4 As shown in the figure The line is the reference trajectory, The line is the trajectory calculated by inertial navigation. The line is the trajectory obtained by the traditional method. The line is the trajectory obtained by the present invention. It can be seen that the method of the present invention is superior to the traditional method, as shown in Table 1.

[0108] Table 1 Analysis of matching errors in simulation experiments

[0109]

[0110] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware portion can be implemented using dedicated logic; the software portion can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. Those skilled in the art will appreciate that the above-mentioned devices and methods can be implemented using computer-executable instructions and / or contained in processor control code, for example, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, or can be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0111] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A gravity vector measurement method, characterized in that: The gravity vector measurement method comprises: According to the benchmark selection principle, the gravity scalar data is decomposed two-dimensionally along the direction of the earth's rotation axis from the perspective of improving the signal-to-noise ratio of the gravity component measurement data. The gravity scalar data is the composite of the three-dimensional measurement results of the gravimeter. Through two-dimensional decomposition, one part of the component is the projection of gravity in the direction of the earth's rotation axis, and the remaining component is determined by vector triangle decomposition; The gravity vector measurement method comprises the following steps: Step 1: The gravity sensitive mechanism measures the gravity data value g in real time; Step 2: The strapdown inertial measurement unit detects the acceleration and angular velocity in the inertial system to determine the direction of the Earth's rotation axis; Step 3: Decompose the gravity value measured in step 1 toward the direction of the earth's rotation axis to obtain the decomposed gravity value g ω and g rest ; Step 4: According to the decomposed gravity value g ω and g rest Perform two-dimensional gravity matching navigation.

2. The gravity vector measurement method according to claim 1, characterized in that: The benchmark selection principles include benchmark measurability, stability and benchmark vector observability.

3. The gravity vector measurement method according to claim 1, characterized in that: The gravity vector measurement method further includes: In the gravity measurement environment, the inertial measurement component determines the direction of the Earth's rotation axis. The projection measurement algorithm is based on the two-dimensional decomposition of the gravity vector of the earth's axis to obtain the projection relationship of the gravity vector under the load system to the earth's axis, thereby realizing the two-dimensional representation of the gravity vector based on the earth's axis.

4. A gravity vector measurement system using the gravity vector measurement method according to any one of claims 1 to 3, characterized in that: The gravity vector measurement system consists of four parts: an inertial stabilization platform, a strapdown gravimeter, a control system chassis, and a data acquisition and processing module; The inertial stabilization platform includes an inertial measurement unit (IMU) and a platform control system, which is used to provide a stable measurement environment for the strapdown gravimeter. The strapdown gravimeter comprises a constant temperature box, a strapdown inertial measurement assembly and a gravity sensitive mechanism; The high-precision three-axis gyroscope installed in the strapdown gravimeter is used to sense the earth's axis and project the three-axis accelerometer measurement value onto the earth's axis. The core is the gravity vector decomposition algorithm; The control system chassis is connected to the strapdown gravimeter and the inertial stabilization platform, and is used to control the inertial stabilization platform and the temperature of the strapdown gravimeter; The data acquisition and processing module is connected to the control system chassis and includes a projection measurement algorithm, a driver, a development environment and a data interface.

5. The gravity vector measurement system according to claim 4, characterized in that: The inertial stabilized platform is also used to track the geoid, which is monitored for stability by a level device.

6. The gravity vector measurement system according to claim 4, characterized in that: The strapdown inertial measurement unit is the core of the strapdown gravimeter; Bell XI accelerometer and Honeywell QA3000 quartz flexure accelerometer were selected.

7. A computer device, characterized in that: The computer device includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the following steps: According to the benchmark selection principle, the gravity scalar data is decomposed two-dimensionally along the direction of the earth's rotation axis from the perspective of improving the signal-to-noise ratio of the gravity component measurement data. The gravity scalar data is the composite of the three-dimensional measurement results of the gravimeter, denoted as g; Through two-dimensional decomposition, one component is the projection of gravity toward the direction of the earth's rotation axis, denoted as g ω , the remaining component is determined by the vector triangle decomposition and is denoted as g rest .

8. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the following steps: According to the benchmark selection principle, the gravity scalar data is decomposed two-dimensionally along the direction of the earth's rotation axis from the perspective of improving the signal-to-noise ratio of the gravity component measurement data. The gravity scalar data is the composite of the three-dimensional measurement results of the gravimeter, denoted as g; Through two-dimensional decomposition, one component is the projection of gravity toward the direction of the earth's rotation axis, denoted as g ω , the remaining component is determined by the vector triangle decomposition and is denoted as g rest .

9. An information data processing terminal, characterized in that: The information data processing terminal is used to implement the gravity vector measurement system as described in any one of claims 4 to 6.

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