Underwater glider dead reckoning method and system

Abstract

The invention discloses an underwater glider dead reckoning method and system, and belongs to the technical field of underwater glider navigation. S1, obtaining basic data; s2, performing position calculation by using a gliding slope; s201, calculating the vertical speed of the underwater glider according to the change rate of the depth data; s202, constructing a mathematical relationship between the vertical velocity and the marine environment parameters; s203, calculating the gliding slope through the mathematical relationship and the glider kinetic equation; s204, calculating east and north horizontal velocity components by using the gliding slope and the vertical velocity in combination with the course angle; s205, calculating a position increment through an integral algorithm according to the east horizontal velocity component and the north horizontal velocity component, and updating the position according to the position increment; s3, compensating the ocean current; and correcting and updating the position by using the ocean current speed. According to the method, underwater dead reckoning is performed by using multiple types of data, and the navigation performance of the underwater glider is improved by means of an ocean current compensation mechanism, so that the requirement of high-precision positioning is met.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater glider navigation, and in particular relates to an underwater glider dead reckoning method and system. Background Art

[0002] As an advanced underwater detection device, underwater gliders play an increasingly important role in many fields such as marine scientific research, marine resource exploration, and marine environmental monitoring. They can operate autonomously for a long time in the vast ocean and collect a large amount of valuable data. However, accurate navigation and positioning underwater has always been a major challenge in this field. Traditional positioning methods, such as those based on a single fluid dynamics model or simple dead reckoning methods, often have large errors and cannot meet the needs of high-precision positioning.

[0003] Although the Global Positioning System (GPS) can provide relatively accurate location information in the water environment, the GPS signal cannot be effectively transmitted in the underwater environment, which makes it difficult for underwater gliders to directly obtain high-precision positioning data when operating underwater. In order to solve this problem, researchers have been exploring and developing various alternative positioning technologies, such as acoustic positioning systems, inertial navigation systems, and underwater acoustic communication technologies. These technologies have made up for the shortcomings of GPS to a certain extent, but there are still some limitations.

[0004] For example, existing gliding slope models have certain limitations in practical applications. These models usually assume that the impact of ocean currents on gliders is uniform and consistent, but in reality, the complexity and variability of ocean currents make this assumption often untenable. In addition, the existing error correction mechanism is not perfect enough and cannot fully consider the impact of various environmental factors on positioning accuracy. These factors restrict the further improvement of underwater glider positioning accuracy and affect its performance in practical applications.

[0005] Therefore, in order to improve the positioning accuracy of underwater gliders, researchers need to further optimize and improve existing positioning models and algorithms, fully consider the influence of multiple environmental factors such as ocean currents, water temperature, salinity, and combine advanced sensor technology to achieve more accurate underwater positioning. Only in this way can underwater gliders play a greater role in fields such as marine scientific research and resource exploration, and provide humans with more accurate and rich marine data. Summary of the invention

[0006] Technical solution, in order to solve the technical problems in the above-mentioned background technology, a method and system for underwater glider dead reckoning is proposed, which uses a variety of sensor data to perform underwater dead reckoning and uses an innovative current compensation mechanism to reduce the impact of various error factors on positioning accuracy, thereby improving the navigation performance of the underwater glider to meet the needs of the ocean field for high-precision positioning of underwater gliders.

[0007] The first object of the present invention is to provide a method for dead reckoning of an underwater glider, comprising:

[0008] S1. Acquire basic data, wherein the basic data includes attitude angle, heading angle, depth data, ocean environment parameters, ocean current speed, dynamic pressure and position information of the underwater glider at different times when the glider is on the water surface;

[0009] S2. Position estimation using glide slope; specifically including:

[0010] S201, calculating the vertical speed of the underwater glider according to the change rate of the depth data;

[0011] S202, constructing a mathematical relationship between vertical velocity and ocean environment parameters;

[0012] S203, calculating the gliding slope by using the mathematical relationship and the glider dynamics equation;

[0013] S204, using the glide slope and the vertical velocity, combined with the heading angle, to calculate the eastward and northward horizontal velocity components;

[0014] S205, calculating the position increment by an integral algorithm according to the eastward and northward horizontal velocity components, and updating the position according to the position increment;

[0015] S3, ocean current compensation; use ocean current speed to correct and update position.

[0016] Preferably, the attitude angle includes a pitch angle and a roll angle.

[0017] Preferably, the ocean environment parameters include seawater density and seawater temperature.

[0018] Preferably, in S1, pressure data of the underwater glider is acquired by using a pressure sensor, and depth data is calculated according to the pressure data;

[0019] In S202, the mathematical relationship is expressed as: Where: q is the dynamic pressure, v is the z is the vertical velocity, ρ is the seawater density, and γ is the glide angle.

[0020] Preferably, the glider dynamics equation is:

[0021] (ql2 ) 2 bq -(1 / 4) -Bql 2 sin(γ)+B 2 cα -2 cos 2 (γ)=0

[0022] cα 2 +aαtan(γ)+bq -(1 / 4) =0

[0023] Where a, b, c are hydrodynamic coefficients, l is the length of the glider, B is the buoyancy, and α is the angle of attack;

[0024] The relationship between the pitch angle θ, the glide angle γ and the angle of attack α is: γ = θ - α;

[0025] The glide angle γ can be solved by iteration; the glide slope is tanγ.

[0026] Preferably, the eastward horizontal velocity component v x The expression is:

[0027] Northward horizontal velocity component v y The expression is:

[0028] in, It refers to the heading angle;

[0029] The expression of position increment is: Δx=v x Δt; Δy=v y Δt;

[0030] The expression for updating the position is: n+1 =x n +Δx;y n+1 =y n +Δy.

[0031] Preferably, in S3, a VMD-LSTM neural network is used for current compensation;

[0032] Measure the ocean current velocity v around the glider current , decomposed into levels (v current,x ,v current,y ) and the vertical component v current,z ;

[0033] VMD-LSTM neural network ocean current impact prediction model:

[0034] Δx current =f(v current,x ,…);

[0035] Δy current =g(v current,y ,…);

[0036] f, g are prediction functions; in dead reckoning, the influence of ocean currents is compensated in real time:

[0037] x compensated =x calc +Δx current ;

[0038] y compensated =y calc +Δy current .

[0039] A second object of the present invention is to provide an underwater glider dead reckoning system, comprising:

[0040] A basic data acquisition module, wherein the basic data includes the attitude angle, heading angle, depth data, ocean environment parameters, ocean current speed, dynamic pressure of the underwater glider at different times, and the position information of the glider when it is on the water surface;

[0041] The dead reckoning module uses the glide slope to perform dead reckoning. Specifically, it includes:

[0042] Calculate the vertical speed of the underwater glider based on the rate of change of depth data;

[0043] Construct mathematical relationships between vertical velocity and ocean environment parameters;

[0044] Calculate the glide slope by using the mathematical relationship and the glider dynamics equation;

[0045] The glide slope and vertical velocity are used to calculate the east and north horizontal velocity components in combination with the heading angle;

[0046] According to the eastward and northward horizontal velocity components, the position increment is calculated by an integration algorithm, and the position is updated according to the position increment;

[0047] The ocean current compensation module uses ocean current speed to correct and update the position.

[0048] The third invention objective of this patent is to provide a computer program product, including a computer program, which implements the above-mentioned underwater glider dead reckoning method when executed by a processor.

[0049] The fourth invention objective of this patent is to provide a computer-readable storage medium, including instructions, which, when run on a computer, enables the computer to execute the above-mentioned underwater glider dead reckoning method.

[0050] The advantages and positive effects of the present invention are:

[0051] The core of the present invention is the integration of a variety of cutting-edge technical means, which include but are not limited to multi-source satellite positioning systems (such as GPS and Beidou systems), high-precision sensor data processing technology, and innovative current compensation algorithms. Through the comprehensive application of these technologies, the present invention can significantly improve the positioning accuracy of underwater gliders in complex and changeable marine environments. This improved positioning accuracy is crucial for the precise navigation of underwater gliders, and also provides more reliable technical support for the collection and monitoring of marine data. In this way, underwater gliders can more accurately locate their own positions when performing tasks, effectively collect marine environmental data, and provide a solid technical foundation for marine scientific research and related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A flowchart of a preferred embodiment of the present invention;

[0053] Figure 2 This is a flow chart of position estimation using glide slope in a preferred embodiment of the present invention;

[0054] Figure 3 It is a flowchart of a method for calculating when the system is running in a preferred embodiment of the present invention;

[0055] Figure 4 It is a schematic diagram of the main angles of the underwater glider motion model in the preferred embodiment of the present invention;

[0056] Figure 5 This is a flow chart of the VMD-LSTM neural network prediction method in a preferred embodiment of the present invention;

[0057] Figure 6 This is a diagram showing an example of dead reckoning results in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0058] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings.

[0059] Table 1 is the parameter definition table

[0060]

[0061]

[0062] See also Figures 1 to 6 , the specific plan is:

[0063] In the first embodiment, a method for dead reckoning of an underwater glider comprises the following steps:

[0064] S1. Acquire basic data, which includes attitude angle, heading angle, depth data, ocean environment parameters, current speed, dynamic pressure and position information of the underwater glider at different times when the glider is on the water surface; specifically:

[0065] High-precision attitude sensors can be used to directly obtain attitude angles (pitch angle θ, roll angle ) and heading angle The attitude sensor should have high stability and low noise characteristics, and its measurement accuracy should be able to meet the requirements of the underwater glider for attitude and heading measurement in complex motion states. When installing the attitude sensor, it needs to be accurately installed in the appropriate position inside the underwater glider to ensure that the attitude changes of the glider can be accurately measured. After installation, the attitude sensor is strictly calibrated using professional calibration equipment to eliminate measurement deviations caused by the installation process or the sensor itself.

[0066] Use high-precision pressure sensors to obtain the depth information of underwater gliders. The pressure sensor should have high resolution and good linearity, and be able to accurately measure the changes in water pressure of the glider at different depths and convert it into accurate depth data. The pressure sensor is installed in a position on the glider that is not disturbed by the water flow and can accurately reflect the depth changes of the glider. Strict accuracy testing is required before installation, and regular calibration is required after installation to ensure the accuracy and reliability of depth measurement.

[0067] The ocean environment parameters mainly include seawater density and seawater temperature, and the ocean environment parameters are collected through density sensors and temperature sensors.

[0068] The ocean current velocity is collected by a current velocity sensor;

[0069] The dynamic pressure is collected by a pressure sensor;

[0070] The position information of the glider when it is on the water surface is obtained through the global positioning system (GPS) or the Beidou positioning system. When the underwater glider is on the water surface, the initial position information (x0, y0, z0) is obtained through the GPS or Beidou satellite positioning system. The positioning system should have fast positioning and high-precision positioning capabilities, and be able to obtain accurate position coordinates in a short time after the glider surfaces. At the same time, the timestamp when the positioning information is obtained is recorded to facilitate the subsequent calculation of the surface drift error.

[0071] S2. Position estimation using glide slope; specifically including:

[0072] S201, calculating the vertical speed of the underwater glider according to the change rate of the depth data;

[0073] Set the initial velocity v0 = 0, and the initial position (x0, y0, z0) is determined by the surface GPS or Beidou positioning system. Use the precise attitude angle and heading angle obtained by the attitude sensor for initialization to ensure that the glider has accurate initial attitude and heading information when starting dead reckoning.

[0074] Depth change rate measured by pressure sensor Calculate the vertical velocity v z .

[0075] S202, constructing a mathematical relationship between vertical velocity and ocean environment parameters;

[0076] Introducing real-time ocean environment parameters (such as seawater density ρ) to optimize the glide slope calculation. Dynamic pressure q and vertical velocity v z The relationship is:

[0077]

[0078] S203, calculating the gliding slope by using the mathematical relationship and the glider dynamics equation;

[0079] The dynamic equation of the glider is:

[0080] (ql 2 ) 2 bq -(1 / 4) -Bql 2 sin(γ)+B 2 cα -2 cos 2 (γ)=0

[0081] cα 2 +aαtan(γ)+bq -(1 / 4) =0

[0082] Where a, b, c are the hydrodynamic coefficients, l is the length of the glider, B is the buoyancy, and α is the angle of attack.

[0083] Combined with the relationship between pitch angle, glide angle and angle of attack:

[0084] γ=θ-α

[0085] The glide angle γ can be solved by iteration;

[0086] The glide slope is tanγ.

[0087] S204, using the glide slope and the vertical velocity, combined with the heading angle, to calculate the eastward and northward horizontal velocity components;

[0088] Using the glide angle γ and vertical velocity v z , combined with the heading angle to calculate the eastward horizontal velocity component v x The expression is:

[0089] Using the glide angle γ and vertical velocity v z , combined with the heading angle to calculate the north horizontal velocity component v y The expression is:

[0090] S205, calculating the position increment and updating the position by an accurate integration algorithm according to the eastward and northward horizontal velocity components;

[0091] The expression of position increment is: Δx=v x Δt; Δy=v y Δt;

[0092] The expression for updating the position is: n+1 =x n +Δx;y n+1 =y n +Δy.

[0093] S3, ocean current compensation; use ocean current speed to correct and update position.

[0094] Install electromagnetic current meter to measure the current velocity v around the glider current , decomposed into levels (v current,x ,v current,y ) and the vertical component v current,z .

[0095] For the horizontal component, a current impact prediction model based on VMD-LSTM neural network is established:

[0096] Δx current =f(v current,x ,…)

[0097] Δy current =g(v current,y ,…)

[0098] f, g are prediction functions. In dead reckoning, the influence of ocean currents is compensated in real time:

[0099] x compensated =x calc +Δx current

[0100] y compensated =y calc +Δy current

[0101] For the vertical component, the buoyancy adjustment system and depth control algorithm are combined. According to the size of the vertical component of the ocean current, the buoyancy is automatically adjusted to make the glider resist the influence of the ocean current in the vertical direction, maintain a stable depth, ensure accurate depth measurement, and indirectly improve the accuracy of dead reckoning.

[0102] The VMD-LSTM neural network prediction method adopted in the present invention combines the advantages of VMD and LSTM, and uses VMD to decompose the original time series to obtain multiple intrinsic mode functions. Each intrinsic mode function represents the components of the original signal at different frequencies and amplitudes, and has better local feature representation. These intrinsic mode functions are used as input sequences, and an LSTM prediction model is constructed for each mode for learning and prediction, thereby improving the prediction performance of the model. The prediction results of each mode are then superimposed and reconstructed to finally obtain an ideal output value.

[0103] A second embodiment is an underwater glider dead reckoning system, which is used to implement the method of the first embodiment. The system includes:

[0104] A basic data acquisition module, wherein the basic data includes the attitude angle, heading angle, depth data, ocean environment parameters, ocean current speed, dynamic pressure of the underwater glider at different times, and the position information of the glider when it is on the water surface;

[0105] The dead reckoning module uses the glide slope to perform dead reckoning. Specifically, it includes:

[0106] Calculate the vertical speed of the underwater glider based on the rate of change of depth data;

[0107] Construct mathematical relationships between vertical velocity and ocean environment parameters;

[0108] Calculate the glide slope by using the mathematical relationship and the glider dynamics equation;

[0109] The glide slope and vertical velocity are used to calculate the east and north horizontal velocity components in combination with the heading angle;

[0110] According to the eastward and northward horizontal velocity components, the position increment is calculated by an integration algorithm, and the position is updated according to the position increment;

[0111] The ocean current compensation module uses ocean current speed to correct and update the position.

[0112] In this embodiment, sensor selection and installation:

[0113] When choosing an attitude sensor with excellent performance and accuracy on the market, make sure it is installed near the center of gravity of the underwater glider or other position that can accurately capture the glider's attitude changes. The installation process must strictly follow the installation guidelines provided by the manufacturer to ensure the accuracy of the installation. After installation, the attitude sensor should be calibrated using professional calibration equipment and procedures. The calibration process must cover all measurement axes of the sensor to ensure the accuracy of attitude and heading angle measurements.

[0114] Select a pressure sensor with high accuracy and excellent resolution, and install it in a position on the glider that is not directly impacted by the water flow and can accurately reflect the depth change, such as an appropriate position on the bottom or side of the glider. Before installation, the pressure sensor should be fully tested for accuracy, including key indicators such as linearity, repeatability, and hysteresis to ensure that the sensor performance meets the standards. Calibration should be performed regularly after installation. The calibration cycle should be determined based on the stability of the sensor and the use environment. It is usually recommended to calibrate once every certain period of time (such as one month or after a mission cycle).

[0115] Select an electromagnetic current meter with high resolution and strong sensitivity, and install it at an appropriate position on the glider to ensure that the ocean current information at different depths around the glider can be fully measured. During installation, care should be taken to avoid electromagnetic interference or physical shielding of the electromagnetic current meter from other equipment to ensure the accuracy of ocean current measurement.

[0116] For GPS or Beidou satellite positioning systems, ensure that the receiving equipment has good signal reception capability and fast positioning performance, and install it on the top of the glider or other locations with good signal reception. At the same time, take protective measures such as waterproofing and anti-collision.

[0117] Data processing and model calculation

[0118] Optimize the frequency of sensor data collection and dynamically adjust the frequency according to the motion state of the underwater glider. When the glider moves smoothly, appropriately reduce the frequency of sensor data collection to reduce data processing and energy consumption; when the glider is in acceleration, turning or complex current environment, the frequency of sensor data collection is increased to ensure that the state changes of the glider can be captured in time to provide accurate data support for dead reckoning.

[0119] In the calculation of the glide slope, accurate ocean environmental parameters are obtained in real time, such as measuring seawater temperature, salinity, density and other parameters through the temperature-salinity-depth sensor (CTD) carried by the glider, or obtaining environmental parameters through wireless data communication with nearby ocean buoys, seabed observatories and other ocean monitoring equipment. These environmental parameters are accurately applied to the glide slope calculation model to improve the accuracy of the glide slope calculation. In the process of speed and position calculation, the speed correction factor and the parameters of the integral algorithm are reasonably adjusted according to the actual hydrodynamic characteristics and motion state of the glider to ensure the accuracy of speed and position calculation.

[0120] The training of the current compensation model should use a large amount of representative historical current data, glider motion data and corresponding dead reckoning error data. The training data should cover different ocean regions, different seasons, different current conditions and other situations to improve the generalization ability of the model. The training data should be updated regularly so that the model can adapt to changes in the marine environment. In practical applications, the current data measured by the electromagnetic current meter is obtained in real time and accurately input into the current compensation model for calculation and compensation.

[0121] Performance evaluation and optimization

[0122] Actual tests of underwater gliders should be carried out under a variety of different marine environmental conditions. The test area should cover different ocean depths, different current strengths and directions, different ocean terrains, etc., to simulate various scenarios of underwater gliders in actual ocean operations and obtain comprehensive and accurate test data.

[0123] The dead reckoning results calculated by the method of the present invention are compared with a high-precision acoustic positioning system or other reliable positioning reference systems. The comparison indicators include statistical indicators such as the mean, standard deviation, and maximum error of the position error. At the same time, the distribution of the errors at different depths, different positions, and different motion states is analyzed, the causes of the errors are deeply analyzed, and the performance advantages and disadvantages of the method of the present invention are evaluated.

[0124] According to the performance evaluation results, the algorithm parameters, sensor configuration or data processing strategy can be adjusted in a targeted manner. For example, if it is found that the current compensation effect in a certain area is not ideal, the parameters of the current compensation model can be further optimized or the training data of the area can be increased; if abnormal fluctuations are found in the sensor data, the sensor installation can be checked to see if it is firmly installed, whether it is disturbed, etc., and corresponding improvement measures can be taken; if it is found that the error correction model is inaccurate in some cases, the model structure can be adjusted or new feature inputs can be added to continuously optimize the dead reckoning method to improve the positioning accuracy and navigation reliability of the underwater glider.

[0125] Figure 6 The numerical simulation results of dead reckoning under two different conditions for actual sea trial data are shown. The specific description is as follows:

[0126] The solid line indicates the estimated trajectory of the device without current compensation. The dotted line indicates the estimated trajectory of the device with real-time current compensation. The square mark indicates the actual water entry position of the device. The triangle mark indicates the actual water exit position of the device. The diamond mark indicates the theoretical water exit position estimated by the device without current compensation. The star mark indicates the theoretical water exit position estimated by the device with real-time current compensation.

[0127] By comparing the actual entry and exit points with the theoretical exit points under two different conditions, it can be seen that the total navigation distance (the distance from the actual entry point to the actual exit point) is 2281.39m, the distance from the actual entry point to the theoretical exit point of the dead reckoning without current compensation is 159.63m, and the distance from the actual entry point to the theoretical exit point of the dead reckoning with real-time current compensation is 6.5m; the exit point errors of the dead reckoning under the two different conditions are 159.63m and 6.5m, and the calculation accuracy is 93% and 99.7% respectively. Therefore, the accuracy of dead reckoning can be significantly improved through real-time current compensation.

[0128] The system works as follows:

[0129] 1. Start the underwater glider, initialize the sensor and model parameters, and obtain various sensor data at the initial moment (including attitude angle, depth, GPS or Beidou positioning information, etc.).

[0130] 2. Enter the main loop, at each time step:

[0131] (1) Collect the latest sensor data, including attitude angle and heading angle data from the attitude sensor, depth data from the pressure sensor, and ocean current data measured by the electromagnetic current meter (if on the water surface, obtain GPS or Beidou positioning data).

[0132] (2) Calculate the glide slope and velocity position based on the glide slope model.

[0133] (3) Perform depth constraint checks and adjustments to ensure the accuracy of glider depth calculations.

[0134] (4) Apply the ocean current compensation mechanism to correct the position calculation results and offset the influence of ocean current on the glider position.

[0135] (5) Record the current dead reckoning result.

[0136] 3. Continue the cycle until the diving mission is completed or the termination condition is met.

[0137] A third embodiment is a computer program product, comprising a computer program, which implements the above-mentioned underwater glider dead reckoning method when executed by a processor.

[0138] A fourth embodiment is an information data processing terminal for an underwater glider dead reckoning method.

[0139] A fifth embodiment is a computer-readable storage medium, comprising instructions, which, when executed on a computer, enable the computer to execute the above-mentioned underwater glider dead reckoning method.

[0140] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When the use is implemented in whole or in part in the form of a computer program product, the computer program product includes one or more computer instructions. When the computer program instructions are loaded or executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL) or wireless (e.g., infrared, wireless, microwave, etc.) mode) to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state hard disk SolidState Disk (SSD)), etc.

[0141] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are within the scope of the technical solution of the present invention.

Claims

1. A method for dead reckoning of an underwater glider, characterized in that: include: S1. Acquire basic data, wherein the basic data includes attitude angle, heading angle, depth data, ocean environment parameters, ocean current speed, dynamic pressure and position information of the underwater glider at different times when the glider is on the water surface; S2. Position estimation using glide slope; specifically including: S201, calculating the vertical speed of the underwater glider according to the change rate of the depth data; S202, constructing a mathematical relationship between vertical velocity and ocean environment parameters; S203, calculating the gliding slope by using the mathematical relationship and the glider dynamics equation; S204, using the glide slope and the vertical velocity, combined with the heading angle, to calculate the eastward and northward horizontal velocity components; S205, calculating the position increment by an integral algorithm according to the eastward and northward horizontal velocity components, and updating the position according to the position increment; S3, ocean current compensation; use ocean current speed to correct and update position.

2. The underwater glider dead reckoning method according to claim 1, characterized in that: The attitude angle includes a pitch angle and a roll angle.

3. The underwater glider dead reckoning method according to claim 1, characterized in that: The ocean environment parameters include seawater density and seawater temperature.

4. The underwater glider dead reckoning method according to claim 1, characterized in that: In S1, the pressure data of the underwater glider is obtained by using a pressure sensor, and the depth data is calculated according to the pressure data; In S202, the mathematical relationship is expressed as: Where: q is the dynamic pressure, v is the z is the vertical velocity, ρ is the seawater density, and γ is the glide angle.

5. The underwater glider dead reckoning method according to claim 4, characterized in that: The glider dynamics equation is: (ql 2 ) 2 bq -(1 / 4) -Bql 2 sin(γ)+B 2 cα -2 cos 2 (γ)=0 cα 2 +aαtan(γ)+bq -(1 / 4) =0 Where a, b, c are hydrodynamic coefficients, l is the length of the glider, B is the buoyancy, and α is the angle of attack; The relationship between the pitch angle θ, the glide angle γ and the angle of attack α is: γ=θ-α; The glide angle γ can be solved by iteration; The glide slope is tanγ.

6. The underwater glider dead reckoning method according to claim 5, characterized in that: Eastward horizontal velocity component v x The expression is: Northward horizontal velocity component v y The expression is: in, It refers to the heading angle; The expression of position increment is: Δx=v x Δt; Δy=v y Δt; The expression for updating the position is: n+1 =x n +Δx;y n+1 =y n +Δy.

7. The underwater glider dead reckoning method according to claim 6, characterized in that: In S3, VMD-LSTM neural network is used for current compensation; Measure the ocean current velocity v around the glider current , decomposed into levels (v current,x ,v current,y ) and the vertical component v current,z ; VMD-LSTM neural network ocean current impact prediction model: Δx current =f(v current,x ,…); Δy current =g(x current,y ,…); f, g are prediction functions; in dead reckoning, the influence of ocean currents is compensated in real time: x compensated =x calc +Δx current ; y compensated =y calc +Δy current 。 8. An underwater glider dead reckoning system, characterized in that: include: A basic data acquisition module, wherein the basic data includes the attitude angle, heading angle, depth data, ocean environment parameters, ocean current speed, dynamic pressure of the underwater glider at different times, and the position information of the glider when it is on the water surface; The dead reckoning module uses the glide slope to perform dead reckoning. Specifically, it includes: Calculate the vertical speed of the underwater glider based on the rate of change of depth data; Construct mathematical relationships between vertical velocity and ocean environment parameters; Calculate the glide slope by using the mathematical relationship and the glider dynamics equation; The glide slope and vertical velocity are used to calculate the east and north horizontal velocity components in combination with the heading angle; According to the eastward and northward horizontal velocity components, the position increment is calculated by an integration algorithm, and the position is updated according to the position increment; The ocean current compensation module uses ocean current speed to correct and update the position.

9. A computer program product, comprising a computer program, characterized in that The computer program is executed by a processor as the underwater glider dead reckoning method according to any one of claims 1 to 7.

10. A computer-readable storage medium comprising instructions, which, when executed on a computer, enables the computer to execute the underwater glider dead reckoning method according to any one of claims 1 to 7.

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