An efficient underwater gravity field information measurement method based on cluster collaboration

Abstract

This invention relates to a highly efficient underwater gravity field information measurement method based on swarm collaboration. It utilizes an unmanned swarm of underwater unmanned vehicles (UUVs) equipped with underwater gravimeters to simultaneously measure gravity information along multiple underwater survey lines. Using a surface vessel as a reference gravimeter, the underwater gravimeter is compared with the reference gravimeter before release and after retrieval to ensure consistency of underwater gravimeter measurement information. After release, the UUV navigates to the starting point of the survey line and, guided by a surface vessel, uses two-stage motion control to maintain the survey line's navigation and formation. Ultra-short baseline positioning and relative ranging are used to determine the UUV's precise position and velocity, enabling accurate compensation and correction of gravity measurements, acquisition of gravity anomaly information along the survey line, and construction of a gravity map. This invention achieves highly efficient underwater gravity measurement and rapid gravity map construction, improving measurement efficiency several times compared to traditional ship-based gravity measurement methods.

Description

Technical Field

[0001] This invention belongs to the field of underwater gravity field mapping, specifically relating to an efficient underwater gravity field information measurement method based on cluster collaboration. Background Technology

[0002] The gravitational field is the combined field of the Earth's gravitational field and the inertial centrifugal force field. The ocean's gravity field often has unique spatial distribution characteristics and is closely related to the local geographical location. By measuring gravity information, the precise position of a carrier can be obtained. Ocean gravity maps are the prerequisite and foundation for gravity matching positioning and navigation, and their accuracy directly affects the accuracy of matching positioning.

[0003] Currently, shipborne gravity measurement remains the primary method for obtaining high-precision ocean gravity maps. However, shipborne gravity measurement is inefficient, requiring the execution of one survey line at a time, and a gravity map can only be created after completing all survey lines in the area. Furthermore, data quality is affected by adverse weather and sea conditions. When shipborne gravity field measurements are used to construct surface gravity maps for underwater platform matching and positioning, the surface gravity map needs to be extended downwards to the depth of the platform, which introduces errors. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a highly efficient underwater gravity field information measurement method based on cluster collaboration, which can quickly construct a gravity map of a specified depth underwater in the area to be mapped.

[0005] The technical solution adopted by this invention to solve the above-mentioned technical problems is as follows: a method for efficient underwater gravity field information measurement based on cluster collaboration, comprising the following steps:

[0006] Step 1: This method is based on a cluster-based high-efficiency underwater gravity field information measurement system. The system consists of an underwater unmanned submersible cluster composed of several unmanned submersibles and a surface vessel. The underwater unmanned submersible cluster is referred to as the unmanned cluster. Each submersible is equipped with an underwater gravimeter, inertial navigation system, Doppler log, depth gauge, ultra-short baseline beacon, and underwater acoustic ranging equipment. The surface vessel is equipped with a high-precision reference gravimeter, ultra-short baseline array, and satellite navigation equipment.

[0007] Step 2: A surface vessel carries an unmanned swarm of drones to the area to be measured. The unmanned swarm consists of n submersibles Q. i Let i = 1, 2, ..., n, and the values ​​of the n underwater gravimeters on the n submersibles be G. i ′(t), i=1,2,...,n, synchronously collect the measurement values ​​of n sets of underwater gravimeters and the reference gravimeter before and after time t1, and calculate the average value. The average value of the n sets of underwater gravimeters is g. i i = 1, 2, ..., n, the mean value of the reference gravimeter is g cMeasure the height difference h between the center of n underwater gravimeter sensors and the center of the reference gravimeter sensor. i i = 1, 2, ..., n;

[0008] Step 3: Design n parallel survey lines in the area to be measured, establish a survey line coordinate system xoy, with the y-axis along the survey line direction and the x-axis on the survey line plane and pointing to the right perpendicular to the survey line. The unmanned cluster is divided into 1 central subgroup and 2 extended subgroups. The extended subgroup, central subgroup and extended subgroup are released in sequence to form the initial formation.

[0009] Step 4: The surface vessel leads the unmanned swarm along its respective survey line to begin constant speed, orientation, and depth navigation, during which the precise position information P of the n submersibles is utilized. i (t), i=1,2,...,n, a two-level nested motion control loop of submersible survey line navigation closed loop and cluster formation closed loop is adopted to realize unmanned cluster survey line navigation and cluster formation maintenance until the survey line navigation is completed;

[0010] Step 5: Utilize the Q submersible i The precise position P of i = 1, 2, ..., n i (t) Obtain the average velocity v1 of the submersible's survey line navigation. i According to the output velocity v′ of the submersible's inertial navigation / Doppler combined navigation. i (t), obtain the average velocity v2 of the submersible's survey line navigation. i Computational latent device Q i Precise speed v during survey line navigation i (t)=v′ i (t)-v2 i +v1 i ;

[0011] Step 6: After all underwater vehicles in the unmanned swarm are recovered to the surface vessel, simultaneously collect measurement data from n sets of underwater gravimeters and a reference gravimeter over a period before and after time t2, and calculate the average value. The average value of the n sets of underwater gravimeters is g. i ′, i=1,2,...,n, the mean value of the reference gravimeter is g′ c Measure the height difference h′ between the center of n underwater gravimeter sensors and the center of the reference gravimeter sensor. i i = 1, 2, ..., n;

[0012] Step 7: Calculate the measured value G of gravity anomaly along the survey line. ni (P i ), i = 1, 2, ..., n, complete the construction of the regional gravity anomaly map;

[0013] Through steps 1-7, the efficient underwater gravity field information measurement system based on cluster collaboration completes the synchronous measurement of gravity anomalies on multiple underwater survey lines at one time, supporting the direct construction of underwater gravity anomaly maps.

[0014] The method described in step 3 for sequentially releasing the extended subgroup, the central subgroup, and the extended subgroup to form the initial formation is as follows:

[0015] 1) The surface vessel completes the nearby release of one central subgroup and two extended subgroups in three separate operations. The submersible, guided by the longitude, latitude and depth information of the inertial navigation / ultra-short baseline combination positioning, hovers at the starting position of the survey line corresponding to the specified depth.

[0016] 2) n submersibles form a cluster formation with two rows along the y-axis, and the front row submersibles and the two adjacent submersibles in the back row form an equilateral triangle;

[0017] 3) After the surface vessel releases all the submersibles, it returns to the starting point of the intermediate survey line. All the submersibles in the central subgroup are within the positioning distance range of the surface vessel's ultra-short baseline array, and the two extended subgroups are located on both sides of the central subgroup.

[0018] The specific steps of the survey line navigation described in step 4 are as follows:

[0019] 1) Determine the precise position P of all unmanned swarm sub-group sub-sub ... i (t), i=1,2,...,n, the inertial navigation system of the submersible is calibrated based on this position information at the starting point of the survey line;

[0020] 2) The surface vessel and each unmanned submersible in the cluster simultaneously begin constant speed, orientation and depth navigation along their respective survey lines. The underwater vessel is guided by satellite navigation. All n submersibles navigate at constant speed, orientation and depth according to constant speed, orientation and depth commands through the control system under the guidance of inertial navigation / Doppler / depth meter combined navigation information, forming a closed-loop control loop for each submersible's survey line navigation.

[0021] 3) During the constant speed, orientation, and depth navigation of n submersibles, based on the submersibles' ultra-short baseline positioning and relative ranging positioning information, the precise position information of all submersibles is obtained through unmanned swarm collaborative positioning, thereby obtaining the unmanned swarm formation. This formation is compared with the target formation; if a deviation occurs, the formation control system adjusts the constant speed, orientation, and depth commands of the n submersibles to maintain the formation. This is the closed-loop control loop of the swarm formation. The above two-level control achieves both survey line navigation and unmanned swarm formation maintenance. The specific steps for constructing the regional gravity anomaly map as described in step 7 are as follows:

[0022] 1) After the surface vessel returns, calculate the offset correction term Δg of the reference gravimeter at times t1 and t2 based on the comparison data of the gravity reference points before and after departure. c, △g′ c ;

[0023] 2) Calculate the measurement correction value G of n sets of underwater gravimeters at time t1. t1i =g c +△g c -g i -kh i The correction value G measured at time t2 t2i =g C ′+△g C ′-g I ′ -kh i ′ ;

[0024] 3) Calculate the measurement correction values ​​during the navigation of n sets of underwater gravimeter survey lines.

[0025] 4) Utilizing the Q-series submersible i The precise position P during the navigation of the survey line, i = 1, 2, ..., n. i (t) and precise velocity v i (t) Achieve the correction value G for gravimeter measurement. i The normal gravity field correction and Etterworth correction of (t) are used to obtain the gravity anomaly value G of the survey line. ni (t), by P i (t) and G ni The time synchronization information of (t) is used to obtain the measured value of gravity anomaly G of the survey line. ni (P i ), i = 1, 2, ..., n, based on the gravity anomaly values ​​G of the n survey lines. ni (P i ), construct a regional gravity anomaly map.

[0026] The advantages and positive effects of this invention are as follows: This invention proposes a highly efficient underwater gravity field information measurement method based on cluster collaboration. Utilizing an unmanned cluster for underwater gravity measurement, it can simultaneously complete the measurement of gravity anomaly information along multiple survey lines without the need for detection lines. Gravity maps can be directly constructed after completion, improving measurement efficiency by more than 10 times compared to existing shipborne measurement methods. This invention uses reference gravimeter measurement information as the baseline information, ensuring the consistency of measurement benchmarks for all underwater gravimeters, which is beneficial for improving the accuracy of gravity measurement and gravity map construction. Simultaneously, it uses a reference gravimeter with long-term high-precision characteristics to calibrate the underwater gravimeters, solving the problem that underwater gravimeters are limited by size, weight, and operating environment, making it difficult to maintain long-term high precision. Using two-stage motion control, the unmanned cluster maintains its formation while navigating along the survey line, which is beneficial for obtaining the precise position information of all submersibles through ultra-short baseline positioning and relative ranging, ensuring the accuracy of underwater gravity measurement correction and compensation. It overcomes the limitation of the ultra-short baseline's effective distance on the number of submersibles, supporting the simultaneous measurement of multiple submersibles along multiple survey lines.

[0027] This invention employs an unmanned swarm of submersibles equipped with underwater gravimeters to achieve synchronous gravity anomaly measurements along multiple survey lines at a specified underwater depth. A single measurement result can directly support the construction of a gravity map at a specified underwater depth in a region, greatly improving the efficiency of gravity field mapping. Attached Figure Description

[0028] Figure 1 This is a diagram showing the composition of the efficient underwater gravity field information measurement system with cluster collaboration according to the present invention.

[0029] Figure 2 This is a schematic diagram of the survey line coordinate system and the initial formation of the unmanned swarm in this invention;

[0030] Figure 3 This is a schematic diagram of the two-stage motion control principle for the unmanned swarm of the present invention. Detailed Implementation

[0031] The present invention will be further described in detail below through specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0032] Step 1: This method is based on a cluster-based high-efficiency underwater gravity field information measurement system. The system consists of an underwater unmanned submersible cluster of n unmanned submersibles and a surface vessel. The underwater unmanned submersible cluster is referred to as the unmanned cluster. Each submersible is equipped with an underwater gravimeter, inertial navigation, Doppler log, depth gauge, ultra-short baseline beacon, and underwater acoustic ranging equipment. The surface vessel is equipped with a high-precision reference gravimeter, ultra-short baseline array, and satellite navigation equipment.

[0033] Underwater gravimeters, limited by size, weight, and application environment, struggle to achieve long-term, high-precision measurements. This paper utilizes the high-precision output information from a surface ship reference gravimeter to correct the drift of the underwater gravimeter, thus achieving high-precision underwater gravity measurement. The components of a cluster-coordinated, high-efficiency underwater gravity field information measurement system are described in [link to documentation]. Figure 1 .

[0034] Step 2: A surface vessel carries an unmanned swarm of drones to the area to be measured. The unmanned swarm consists of n submersibles Q. i Let i = 1, 2, ..., n. Adjust the equipment time of the n submersibles, the surface vessel reference gravimeter time, the ultra-short baseline time, and the satellite navigation time to be consistent. The measurement value of the n sets of underwater gravimeters of the n submersibles is G. i ′(t), i=1,2,...,n, synchronously collect measurements from n sets of underwater gravimeters and a reference gravimeter for a total of 20 minutes before and after time t1, and calculate the average value. The average value of the n sets of underwater gravimeters is g. i i =

[0035] 1, 2, ..., n, the mean value of the reference gravimeter is g c Measure the height difference h between the center of n underwater gravimeter sensors and the center of the reference gravimeter sensor. i i = 1, 2, ..., n, with upward values ​​being positive.

[0036] Step 3: Design n parallel survey lines in the area to be measured, establish a survey line coordinate system xoy, with the y-axis along the survey line direction and the x-axis in the survey line plane and perpendicular to the survey line pointing to the right. The design of the survey lines and coordinate system is as follows: Figure 2 As shown, the unmanned swarm is divided into one central subgroup and two extended subgroups. The central subgroup contains seven submersibles, and each extended subgroup contains four submersibles, i.e., n=15. The surface vessels successively release the three unmanned swarm subgroups to form the initial formation. The central subgroup is located in the middle of the survey line, and the two extended subgroups are positioned on the left and right sides of the central subgroup to form the initial formation. The specific method is as follows:

[0037] 1) From left to right, the surface vessel releases the extended subgroup, central subgroup, and then the next extended subgroup on the side of the survey line's starting point. Guided by inertial navigation / ultra-short baseline (USBB) positioning information (longitude, latitude, and depth gauge), the submersibles hover at the designated depth corresponding to the survey line's starting point. After releasing all submersibles in the extended subgroup, the surface vessel waits for all submersibles to reach their starting points before navigating to the central subgroup release position. After releasing all submersibles in the central subgroup, the surface vessel waits for all submersibles to reach their starting points before navigating to the second extended subgroup release position. Finally, after releasing all submersibles in the extended subgroup, the surface vessel waits for all submersibles to reach their starting points before navigating to the intermediate survey line's starting point. During the release process, it is essential to ensure that all submersibles have USBBB positioning information from the surface vessel while navigating to the starting points.

[0038] 2) n submersibles are adjusted by attitude control so that the vertical axis is parallel to the y-axis, forming a cluster formation of two rows along the y-axis. The front row of submersibles and the two adjacent submersibles in the back row form an equilateral triangle. The formation of the equilateral triangle is to ensure the accuracy of the submersible positioning using relative ranging information.

[0039] 3) After the surface vessel releases all the submersibles, it returns to the starting point of the intermediate survey line. All the submersibles in the central subgroup are within the positioning distance range of the surface vessel's ultra-short baseline array, and the two extended subgroups are located on both sides of the central subgroup.

[0040] Step 4: The surface vessel leads the unmanned swarm along its respective survey line to begin constant speed, orientation, and depth navigation, during which the precise position information P of the n submersibles is utilized. i (t), i = 1, 2, ..., n, employs a two-stage nested motion control loop—a closed-loop control loop for submersible surveying and a closed-loop control loop for cluster formation—to achieve unmanned cluster surveying and formation maintenance until surveying is complete. Maintaining the cluster formation serves two purposes: first, to ensure the accuracy of positioning the two extended sub-group submersibles based on relative ranging information; and second, to ensure measurement synchronization. The two-stage navigation motion control flow is as follows: Figure 3 As shown, the specific steps are as follows:

[0041] 1) Determine the precise position P of each unmanned swarm submersible based on the ultra-short baseline positioning of the central subgroup submersible and the relative ranging information of the unmanned swarm submersibles. i (t), i=1,2,...,15, the inertial navigation system of the submersible is calibrated based on this position information at the starting point of the survey line;

[0042] The specific method for determining the precise location of each submersible in the entire underwater unmanned swarm is as follows:

[0043] ①The central subgroup of submersibles directly uses the ultra-short baseline array positioning information of surface ships as its precise position information;

[0044] ② Extended subgroup potential Q x Precise location information determination method: Determining distance Q in an unmanned swarm x Two recently discovered underwater vehicles, Q1 and Q2, have known precise locations. x Relative ranging information len1, Q to Q1 x Given the relative distance measurement information len2 to Q2, find the coordinates of the two intersection points of the circle centered at Q1 with radius len1 and the circle centered at Q2 with radius len2. Then, based on Q... x The relative positional relationship with Q1 and Q2, that is, determining the coordinates of one of the intersection points, is Q. x Precise location information.

[0045] 2) The surface vessels and the unmanned swarm of submersibles synchronously begin constant-speed, constant-orientation, and constant-depth navigation along their respective survey lines, while the underwater vessels are guided by satellite navigation. Each of the n submersibles navigates at a constant speed, constant orientation, and constant depth according to constant-speed, constant-orientation, and constant-depth commands via its control system, guided by inertial navigation / Doppler / depthmeter integrated navigation information, forming a closed-loop control loop for each submersible's survey line navigation. Inertial navigation / Doppler / depthmeter integrated navigation information is chosen as the guidance information because it is continuous and stable. Although inertial navigation / ultra-short baseline integrated positioning has high accuracy, it has greater position and velocity noise and occasional outliers, affecting the stability of navigation control.

[0046] 3) During the constant speed, orientation, and depth navigation of n submersibles, based on the submersibles' ultra-short baseline positioning and relative ranging positioning information, the precise position information of all submersibles is obtained through unmanned swarm collaborative positioning, thereby obtaining the unmanned swarm formation. This formation is compared with the target formation; if a deviation occurs, the formation control system adjusts the constant speed, orientation, and depth commands of the n submersibles to maintain the formation. This is the closed-loop control loop of the swarm formation. The above two-level control achieves both survey line navigation and unmanned swarm formation maintenance.

[0047] Step 5: Utilize the Q submersible i The precise position P of i = 1, 2, ..., 15 i (t) Differential acquisition of the speed v″ during the submersible's survey route i (t), v″ i (t) Calculate the average speed v1 obtained from the survey line navigation. i The output velocity v′ of the submersible's inertial navigation / Doppler integrated navigation system. i (t), v′ i (t) Calculate the average speed v2 of the submersible during its survey route acquisition. i Computational latent device Q i Precise speed v during survey line navigation i (t)=v′ i (t)-v2 i +v1 i The inertial navigation / Doppler combined navigation system outputs a velocity with small fluctuations, the main error being the water current velocity, which remains relatively constant over a short period in a small area. The submersible's precise position differential velocity calculation introduces high-frequency components during the differential process, resulting in higher velocity noise, but the average velocity obtained is more accurate. Therefore, combining these two velocity calculation methods yields accurate and stable velocity information.

[0048] Step 6: All underwater vehicles in the unmanned swarm are recovered to the surface vessel. After the underwater gravimeter output stabilizes, the measurement data from 15 sets of underwater gravimeters and the reference gravimeter are simultaneously collected for 20 minutes (10 minutes before and after time t2). The average value of the 15 sets of underwater gravimeters is calculated as g. i′, i=1,2,...,n, the mean value of the reference gravimeter is g′ c The height difference h′ between the center of 15 underwater gravimeter sensors and the center of the reference gravimeter sensor was measured. i i = 1, 2, ..., n, with upward direction being positive;

[0049] Step 7: Calculate the measured value G of gravity anomaly along the survey line. ni (P i For each i = 1, 2, ..., 15, the regional gravity anomaly map is constructed. The specific steps are as follows:

[0050] 1) After the surface vessel returns, calculate the offset correction term Δg of the reference gravimeter at times t1 and t2 based on the comparison data of the gravity reference points before and after departure. c =1.2mGal, △g′ c =1.25mGal.

[0051] 2) Calculate the correction value G for measurements at time t1 using 15 sets of underwater gravimeters. t1i =g c +△g c -g i -kh i The correction value G measured at time t2 t2i =g′ c +△g′ c -g i ′-kh i ′, k=0.3086; the survey line correction includes two types of correction: one is to correct the relative gravity measurement to the absolute gravity measurement, and the other is to correct the drift of the underwater gravimeter during the measurement process based on the output of the reference gravimeter.

[0052] 3) Calculate the correction values ​​for the measurement lines of n underwater gravimeters.

[0053] 4) Utilizing the Q-series submersible i The precise location P of the survey line, where i = 1, 2, ..., n. i (t) and precise velocity v i (t) Achieve the correction value G for gravimeter measurement. i The normal gravity field correction and Etterworth correction of (t) are used to obtain the gravity anomaly value G of the survey line. ni (t). By P i (t) and G ni The time synchronization information of (t) is used to obtain the gravity anomaly value G of the survey line. ni (P i ), i = 1, 2, ..., n, based on the gravity anomaly values ​​G of 15 survey lines ni (P i ), and completed the construction of the regional gravity anomaly map.

[0054] Through steps 1-7, the efficient underwater gravity field information measurement system based on cluster collaboration completes the synchronous measurement of gravity anomaly information in the area, and realizes the rapid construction of gravity anomaly maps.

Claims

1. A highly efficient underwater gravity field information measurement method based on cluster collaboration, characterized in that: Includes the following steps: Step 1: This method is based on a cluster-based high-efficiency underwater gravity field information measurement system. The system consists of an underwater unmanned submersible cluster composed of several unmanned submersibles and a surface vessel. The underwater unmanned submersible cluster is referred to as the unmanned cluster. Each submersible is equipped with an underwater gravimeter, inertial navigation system, Doppler log, depth gauge, ultra-short baseline beacon, and underwater acoustic ranging equipment. The surface vessel is equipped with a high-precision reference gravimeter, ultra-short baseline array, and satellite navigation equipment. Step 2: A surface vessel carries an unmanned swarm of drones to the area to be measured. The unmanned swarm consists of n submersibles Q. i Let i = 1, 2, ..., n, and n be the values ​​measured by n sets of underwater gravimeters on n submersibles. Simultaneously collect measurements from n sets of underwater gravimeters and a reference gravimeter over a period before and after time t1, and calculate the average value. The average value of the n sets of underwater gravimeters is... The average value of the reference gravimeter is Measure the height difference between the center of n underwater gravimeter sensors and the center of the reference gravimeter sensor. ; Step 3: Design n parallel survey lines in the area to be measured, establish a survey line coordinate system xoy, with the y-axis along the survey line direction and the x-axis on the survey line plane and pointing to the right perpendicular to the survey line. The unmanned cluster is divided into 1 central subgroup and 2 extended subgroups. The extended subgroup, central subgroup and extended subgroup are released in sequence to form the initial formation. Step 4: The surface vessel leads the unmanned swarm along its respective survey line to begin constant speed, orientation, and depth navigation, utilizing the precise position information of the n submersibles during the process. The unmanned swarm survey navigation and swarm formation maintenance are achieved by using a two-level nested motion control loop consisting of a submersible survey navigation closed-loop control loop and a swarm formation closed-loop control loop, until the survey navigation is completed. Step 5: Utilize the Q submersible i precise location Obtain the average speed of the submersible during its survey route. Based on the output speed of the submersible's inertial navigation / Doppler combined navigation Obtain the average speed of the submersible during its survey route. Computational latent device Q i Precise speed during survey line navigation ; Step 6: After all underwater vehicles in the unmanned swarm are recovered to the surface vessel, simultaneously collect measurement data from n sets of underwater gravimeters and a reference gravimeter over a period before and after time t2, and calculate the average value. The average value of the n sets of underwater gravimeters is... , Measure the height difference between the center of n underwater gravimeter sensors and the center of the reference gravimeter sensor. ; Step 7: Calculate the measured gravity anomaly values ​​of the survey line. Complete the construction of the regional gravity anomaly map; Through steps 1-7, the efficient underwater gravity field information measurement system based on cluster collaboration completes the synchronous measurement of gravity anomalies on multiple underwater survey lines at one time, supporting the direct construction of underwater gravity anomaly maps.

2. The efficient underwater gravity field information measurement method based on cluster collaboration according to claim 1, characterized in that: The method described in step 3 for sequentially releasing the extended subgroup, the central subgroup, and the extended subgroup to form the initial formation is as follows: 1) The surface vessel completes the nearby release of one central subgroup and two extended subgroups in three separate operations. The submersible, guided by the longitude, latitude and depth information of the inertial navigation / ultra-short baseline combination positioning, hovers at the starting position of the survey line corresponding to the specified depth. 2) n submersibles form a cluster formation with two rows along the y-axis, and the front row submersibles and the two adjacent submersibles in the back row form an equilateral triangle; 3) After the surface vessel releases all the submersibles, it returns to the starting point of the middle survey line. All the submersibles in the central subgroup are within the positioning distance range of the surface vessel's ultra-short baseline array, and the two extended subgroups are located on both sides of the central subgroup.

3. The efficient underwater gravity field information measurement method based on cluster collaboration according to claim 1, characterized in that: The specific steps of the survey line navigation described in step 4 are as follows: 1) Determine the precise positions of all unmanned swarm sub-group sub-sub ... At the starting point of the survey line, the inertial navigation system of the submersible is calibrated based on this position information; 2) The surface vessel and each unmanned submersible in the cluster simultaneously begin constant speed, orientation and depth navigation along their respective survey lines. The underwater vessel is guided by satellite navigation. All n submersibles navigate at constant speed, orientation and depth according to constant speed, orientation and depth commands through the control system under the guidance of inertial navigation / Doppler / depth meter combined navigation information, forming a closed-loop control loop for each submersible's survey line navigation. 3) During the constant speed, orientation, and depth navigation of n submersibles, based on the ultra-short baseline positioning and relative ranging positioning information of the submersibles, the precise position information of all submersibles is obtained through unmanned swarm collaborative positioning, thereby obtaining the unmanned swarm formation. When compared with the target formation, if there is a deviation, the formation control system adjusts the constant speed, orientation, and depth commands of the n submersibles to maintain the formation. This is the closed-loop control loop of the swarm formation. The above two-level control realizes the survey line navigation and the maintenance of the unmanned swarm formation.

4. The efficient underwater gravity field information measurement method based on cluster collaboration according to claim 1, characterized in that: The specific steps for constructing the regional gravity anomaly map as described in step 7 are as follows: 1) After the surface vessel returns, calculate the offset correction terms of the reference gravimeter at times t1 and t2 based on the comparison data of the gravity benchmark before and after departure. , ; 2) Calculate the measurement correction values ​​of n sets of underwater gravimeters at time t1. Correction value measured at time t2 ; 3) Calculate the measurement correction values ​​during the navigation of n sets of underwater gravimeter survey lines. ; 4) Utilizing the Q-series submersible i Precise location during survey line navigation Precise speed Achieve gravimeter measurement correction values Normal gravity field correction and Ertworth correction were used to obtain gravity anomaly values ​​for the survey line. ,Depend on and Time synchronization information is used to obtain the measured values ​​of gravity anomalies along the survey line. Based on the gravity anomaly values ​​of n survey lines Construct a regional gravity anomaly map.

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