An inertial navigation-based positioning method and system for marine resource exploration

Abstract

The application belongs to the technical field of marine exploration, and discloses a marine resource exploration positioning method and system based on inertial navigation, which comprises the following steps: determining the current depth of a marine exploration carrier according to sonar data; when the current depth of the marine exploration carrier is less than a preset depth, processing satellite positioning position and a first inertial position based on a filtering algorithm to obtain an error estimation value, correcting the first inertial position with the error estimation value to obtain a first actual position; determining an error estimation change value according to a plurality of error estimation values within a preset time length; after the current depth of the marine exploration carrier reaches the preset depth, preliminarily correcting a second inertial position with the error estimation change value, determining a secondary correction amount based on the preliminarily corrected second inertial position and a geomagnetic measurement value, and determining a second actual position based on the secondary correction amount and the preliminarily corrected second inertial position. The application has high underwater positioning precision.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of marine exploration, and particularly relates to a marine resource exploration positioning method and system based on inertial navigation. BACKGROUND

[0002] Marine resource exploration refers to the process of finding and evaluating various resources in the ocean through scientific methods and technical means. This includes but is not limited to oil, natural gas, renewable resources (such as wind energy, solar energy), and marine biological resources. The importance of marine resource exploration lies in its foundation for the development and utilization of marine resources, which has a significant impact on national energy security, economic development, and ecological civilization construction.

[0003] In marine resource exploration, accurate positioning and tracking systems are crucial as they help determine the location of resources, monitor the status of exploration equipment, and ensure the safety and efficiency of operations.

[0004] Currently, common positioning technologies include GNSS (Global Navigation Satellite System) positioning and inertial navigation positioning, as well as fusion positioning methods combining GNSS positioning and inertial navigation positioning. Due to the influence of water depth on GNSS signals, underwater exploration equipment cannot provide continuous GNSS positioning services, while inertial navigation positioning accumulates large errors as the duration of GNSS signal loss increases, making it unable to provide accurate positioning services underwater. SUMMARY

[0005] The purpose of the present application is to provide a marine resource exploration positioning method and system based on inertial navigation to solve the problem that existing positioning methods cannot provide accurate positioning services underwater.

[0006] To achieve the above purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a marine resource exploration positioning method based on inertial navigation, which comprises:

[0008] Obtaining sonar data of a marine exploration carrier, and determining the current depth of the marine exploration carrier based on the sonar data;

[0009] When the current depth of the marine exploration carrier is less than a preset depth, obtaining the satellite positioning position and the first inertial position of the marine exploration carrier;

[0010] Processing the satellite positioning position and the first inertial position based on a filtering algorithm to obtain an error estimate value, and correcting the first inertial position with the error estimate value to obtain the first actual position of the marine exploration carrier at the current depth;

[0011] a plurality of error estimation values within a preset time length are recorded, and an error estimation change value is determined according to the plurality of error estimation values within the preset time length;

[0012] after the current depth of the marine exploration carrier reaches a preset depth, a geomagnetic measurement value and a second inertial position are obtained;

[0013] the second inertial position is preliminarily corrected by using the error estimation change value, a secondary correction amount is determined based on the preliminarily corrected second inertial position and the geomagnetic measurement value, and a second actual position of the marine exploration carrier at the current depth is determined based on the secondary correction amount and the preliminarily corrected second inertial position.

[0014] Preferably, the filtering algorithm is a Kalman filtering algorithm, the satellite positioning position and the first inertial position are processed based on the filtering algorithm to obtain an error estimation value, the first inertial position is corrected by using the error estimation value to obtain a first actual position of the marine exploration carrier at the current depth, and the method comprises:

[0015] the first inertial position is used as an observation quantity of the Kalman filtering algorithm, and the satellite positioning position is used as a state quantity of a Kalman filtering model to predict an error estimation value of an error state quantity;

[0016] the first inertial position is corrected according to the error estimation value of the error state quantity to obtain a corrected first inertial position, and the corrected first inertial position is used as the first actual position of the marine exploration carrier at the current depth.

[0017] Preferably, the secondary correction amount is determined based on the preliminarily corrected second inertial position and the geomagnetic measurement value, and the method comprises:

[0018] a prediction area is constructed based on the preliminarily corrected second inertial position;

[0019] the prediction area is meshed, a plurality of meshes are determined, a central geomagnetic reference value of each mesh and a distance between the center of each mesh and the preliminarily corrected second inertial position are determined;

[0020] a distribution probability of a real position falling into each mesh is calculated according to the geomagnetic measurement value and the central geomagnetic reference value of each mesh;

[0021] the secondary correction amount is determined according to the distance between the center of each mesh and the preliminarily corrected second inertial position and the distribution probability of the real position falling into each mesh.

[0022] Preferably, the distribution probability of the real position falling into each mesh is calculated according to the geomagnetic measurement value and the central geomagnetic reference value of each mesh, and the method comprises:

[0023] Based on geomagnetic measurements and the central geomagnetic reference value of each grid, the geomagnetic normal distribution probability is calculated. The geomagnetic normal distribution probability is used to characterize the probability that the geomagnetic reference value of the grid is the geomagnetic measurement value when the actual location falls into any grid.

[0024] Calculate the initial probability of each grid cell based on the number of grid cells;

[0025] Calculate the output probability of each grid based on the initial probability and the geomagnetic normal distribution probability;

[0026] The evaluation index is calculated based on the output probability of each grid. It is then determined whether the evaluation index reaches the preset threshold. When the evaluation index reaches the preset threshold, the output probability of each grid is used as the distribution probability of the actual position falling into each grid.

[0027] When the evaluation index does not reach the preset threshold, the output probability of each grid is used as the new initial probability of each grid. The calculation of the output probability of each grid based on the initial probability and the geomagnetic normal distribution probability is repeated. The evaluation index is calculated based on the output probability of each grid. When the evaluation index reaches the preset threshold, the output probability of each grid corresponding to the evaluation index at the preset threshold is used as the distribution probability of the actual position falling into each grid.

[0028] Preferably, the expression for calculating the output probability of each grid is:

[0029] ;

[0030] In the formula, For the prediction of the region's first i row and number j The output probability of the grid of columns, For the prediction of the region's first i row and number j Column grid, I The total number of rows in the grid. J The total number of columns in the grid. I and J All are odd numbers. The probability is a geomagnetic normal distribution. g These are geomagnetic measurements. For the prediction of the region's first i row and number j The initial grid probabilities of the column, where, .

[0031] Preferably, the expression for calculating the geomagnetic normal distribution probability is:

[0032] ;

[0033] In the formula, a magnetic normal distribution probability, a first row and a first column of a grid of the estimation area, i a first row and a first column of a grid of the estimation area, j a magnetic measurement value, a first row and a first column of a grid of the estimation area, i a first row and a first column of a grid of the estimation area, j a first row and a first column of a grid of the estimation area, a first coefficient, a second coefficient, and e is a natural base.

[0034] Preferably, the calculation expression of the second actual position of the marine exploration carrier at the current depth is:

[0035] ;

[0036] wherein, the second actual position of the marine exploration carrier at the current depth, a second inertial position, a first row and a first column of a grid of the estimation area, i a first row and a first column of a grid of the estimation area, j a first row and a first column of a grid of the estimation area, an error estimation change value, a second correction amount.

[0037] Preferably, the marine exploration carrier is provided with an inertial measurement unit, the first inertial position and the second inertial position are determined by the inertial measurement unit, and the inertial measurement unit comprises: an accelerometer and a gyroscope, the accelerometer is used to collect acceleration values of the marine exploration carrier in real time, and the gyroscope is used to collect angular velocity values of the marine exploration carrier in real time.

[0038] Preferably, the marine exploration carrier is provided with a transmitting sonar probe and a plurality of receiving sonar probes, and the sonar data comprises: second echo signals received by the plurality of receiving sonar probes.

[0039] The sonar data of the marine exploration carrier is acquired, and the current depth of the marine exploration carrier is determined according to the sonar data, comprising:

[0040] The current attitude of the marine exploration carrier is acquired, and the height difference between each receiving sonar probe and the transmitting sonar probe in the vertical direction is determined according to the current attitude;

[0041] The second echo signals received by each receiving sonar probe are filtered to obtain a plurality of processed second echo signals;

[0042] The detection depths of the receiving sonar probes are calculated according to the processed second echo signals of the receiving sonar probes and the corresponding receiving interval durations.

[0043] According to the detection depth of each receiving sonar probe and the height difference between each receiving sonar probe and the transmitting sonar probe in the vertical direction, the current depth of the marine exploration carrier is determined.

[0044] In a second aspect, the present application provides a marine resource exploration positioning system based on inertial navigation, which is used to implement the marine resource exploration positioning method based on inertial navigation, and comprises:

[0045] a depth determination module, configured to acquire sonar data of the marine exploration carrier, and determine the current depth of the marine exploration carrier according to the sonar data;

[0046] a first acquisition module, configured to acquire a satellite positioning position and a first inertial position of the marine exploration carrier when the current depth of the marine exploration carrier is less than a preset depth;

[0047] a first calculation module, configured to process the satellite positioning position and the first inertial position based on a filtering algorithm to obtain an error estimation value, correct the first inertial position with the error estimation value to obtain a first actual position of the marine exploration carrier at the current depth;

[0048] an error recording module, configured to record a plurality of error estimation values within a preset time length, and determine an error estimation change value according to the plurality of error estimation values within the preset time length;

[0049] a second acquisition module, configured to acquire a geomagnetic measurement value and a second inertial position when the current depth of the marine exploration carrier reaches the preset depth;

[0050] a second calculation module, configured to preliminarily correct the second inertial position with the error estimation change value, determine a secondary correction amount based on the preliminarily corrected second inertial position and the geomagnetic measurement value, and determine a second actual position of the marine exploration carrier at the current depth based on the secondary correction amount and the preliminarily corrected second inertial position.

[0051] Beneficial effects:

[0052] The present application determines the current depth of the marine exploration carrier through sonar data, and when the water depth is shallow, the first actual position of the marine exploration carrier at the current depth can be accurately calculated by using the satellite positioning position and the first inertial position. When calculating the first actual position, a plurality of error estimation values are recorded, which are used to represent the error of the first inertial position in the positioning service. Then the error change value is determined in a period of time. When the water depth is deep, the stability of the satellite signal is poor, and the error estimation change value is used as a reference factor for the correction of the second inertial position. Then the second correction amount is determined through the geomagnetic measurement value. Finally, the second actual position of the marine exploration carrier at the current depth is calculated by combining the error estimation change value and the second correction amount, so as to improve the positioning accuracy of the marine exploration carrier in deep water. BRIEF DESCRIPTION OF DRAWINGS

[0053] The accompanying drawings are included to provide a further understanding of the embodiments of the present application, and constitute a part of the specification, and are used together with the following detailed description to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the drawings:

[0054] Figure 1 is a flow chart of a marine resource exploration positioning method based on inertial navigation provided by an embodiment of the present application;

[0055] Figure 2 is a block diagram of a marine resource exploration positioning system based on inertial navigation provided by an embodiment of the present application. DETAILED DESCRIPTION

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the present application will be briefly introduced below in combination with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the drawings structure is only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor. It should be noted that the description of these embodiment modes is used to help understand the present application, but does not constitute a limitation on the present application.

[0057] Embodiment one

[0058] Figure 1 is a flow chart of a marine resource exploration positioning method based on inertial navigation provided by an embodiment of the present application, as shown in Figure 1 The present embodiment provides a marine resource exploration positioning method based on inertial navigation, which comprises:

[0059] Step S10: Obtain the sonar data of the marine exploration carrier, and determine the current depth of the marine exploration carrier according to the sonar data.

[0060] In the embodiment, the marine exploration carrier is provided with a transmitting sonar probe and a plurality of receiving sonar probes, the receiving sonar probes are installed at different positions of the marine exploration carrier to ensure that the transmitting sonar probe can timely receive echo signals, and the sonar data include second echo signals received by the receiving sonar probes.

[0061] Since the current depth of the marine exploration carrier needs to be relied on when the water depth is deep, the depth position of the marine exploration carrier needs to be accurately calculated. Specifically, sonar data of the marine exploration carrier are acquired, and the current depth of the marine exploration carrier is determined according to the sonar data, including:

[0062] Step S101: acquiring a current attitude of the marine exploration carrier, and determining height differences between the receiving sonar probes and the transmitting sonar probe in a vertical direction respectively according to the current attitude;

[0063] Step S102: performing filtering processing on the second echo signals received by the receiving sonar probes to obtain a plurality of processed second echo signals;

[0064] Step S103: calculating detection depths of the receiving sonar probes according to the processed second echo signals of the receiving sonar probes and corresponding receiving interval durations;

[0065] Step S104: determining the current depth of the marine exploration carrier according to the detection depths of the receiving sonar probes and the height differences between the receiving sonar probes and the transmitting sonar probe in the vertical direction respectively.

[0066] Step S20: acquiring a satellite positioning position and a first inertial position of the marine exploration carrier when the current depth of the marine exploration carrier is less than a preset depth.

[0067] In the embodiment, the preset depth can be a water depth within 1 m or on the water surface. Within the preset depth, satellite signals can be acquired, and the accurate position of the marine exploration carrier is determined by using a fusion positioning mode of satellite and inertial navigation positioning.

[0068] In the embodiment, the marine exploration carrier is provided with a satellite positioning unit and an inertial measurement unit. The satellite positioning unit is configured to receive satellite signals to calculate a current satellite positioning position of the marine exploration carrier. The inertial measurement unit includes an accelerometer and a gyroscope. The accelerometer is configured to detect an acceleration value of the marine exploration carrier in real time, and the gyroscope is configured to collect an angular velocity value of the marine exploration carrier in real time. The first inertial position of the marine exploration carrier can be obtained by integrating the acceleration value and the angular velocity value. However, as the integral time increases, the error of the inertial measurement unit increases with the increase of the positioning time, resulting in a large deviation between the first inertial position calculated by the inertial measurement unit and the actual position of the marine exploration carrier. Therefore, in the fusion positioning mode, the satellite positioning position is used to correct the first inertial position, so as to improve the positioning accuracy of the marine exploration carrier.

[0069] Step S30: processing the satellite positioning position and the first inertial position based on a filtering algorithm to obtain an error estimation value, correcting the first inertial position based on the error estimation value to obtain a first actual position of the marine exploration carrier at the current depth.

[0070] Specifically, the filtering algorithm is a Kalman filtering algorithm. The satellite positioning position and the first inertial position are processed based on the filtering algorithm to obtain an error estimation value, and the first inertial position is corrected based on the error estimation value to obtain a first actual position of the marine exploration carrier at the current depth, including:

[0071] Step S301: taking the first inertial position as an observation of the Kalman filtering algorithm, and taking the satellite positioning position as a state quantity of a Kalman filtering model to predict an error estimation value of an error state quantity;

[0072] Step S302: correcting the first inertial position based on the error estimation value of the error state quantity to obtain a corrected first inertial position, and taking the corrected first inertial position as the first actual position of the marine exploration carrier at the current depth.

[0073] In the embodiment, due to the recursive nature of the Kalman filtering algorithm, its calculation complexity is relatively low, which is suitable for real-time application and systems with limited computing resources, and can improve the real-time performance and accuracy of the calculation of the first actual position of the marine exploration carrier at the current depth.

[0074] Step S40: recording a plurality of error estimation values within a preset time period, and determining an error estimation change value based on the plurality of error estimation values within the preset time period.

[0075] In the embodiment, when the marine exploration carrier needs to continuously work in the water area of the preset depth for a time period longer than a preset time period, the preset time period can be 2-5 minutes, the error estimation value calculated in the collecting step S301 is collected in the preset time period, and then the plurality of error estimation values are fitted to obtain an error function of the inertial measurement unit, the error function is used to represent the change of the error estimation value with the increase of the positioning time period; after the marine exploration carrier sinks to the water area of the water depth of 1 m or less, the satellite signal is lost at this time, and the error estimation change value can be calculated according to the lost time period of the satellite signal and the error function, the error estimation change value can be the error estimation instantaneous value calculated by bringing the current time into the error function, or can be the error estimation average value in the lost time period, and the embodiment preferably selects the error estimation average value in the lost time period as the error estimation change value.

[0076] Step S50: After the current depth of the marine exploration carrier reaches the preset depth, the geomagnetic measurement value and the second inertial position are obtained.

[0077] In the embodiment, the marine exploration carrier is provided with a geomagnetic instrument, the geomagnetic instrument is used to detect the geomagnetic signal of the marine exploration carrier at the current position to obtain the geomagnetic measurement value, and the second inertial position is also calculated by the inertial measurement unit.

[0078] Step S60: The second inertial position is preliminarily corrected by using the error estimation change value, the secondary correction amount is determined based on the preliminarily corrected second inertial position and the geomagnetic measurement value, and the second actual position of the marine exploration carrier at the current depth is determined based on the secondary correction amount and the preliminarily corrected second inertial position.

[0079] Specifically, the secondary correction amount is determined based on the preliminarily corrected second inertial position and the geomagnetic measurement value, including:

[0080] Step a10: The estimated area is constructed based on the preliminarily corrected second inertial position.

[0081] In the embodiment, the size of the estimated area can be a square area of 50m*50m, if the real position of the marine exploration carrier falls into the square area, the relative position relationship between the real position and the second inertial position can be calculated, and the real position of the marine exploration carrier can be estimated.

[0082] Step a20: The estimated area is divided into a plurality of grids, the center geomagnetic reference value of each grid and the distance between the center of each grid and the preliminarily corrected second inertial position are determined.

[0083] In the embodiment, the size of each grid can be a square lattice of 1m*1m, a square lattice of 2m*2m, or a rectangular lattice of 2m*1m; since the estimation area is constructed based on the second inertia position, the distance between the center of each grid and the second inertia position after the preliminary correction can be directly calculated; meanwhile, the geomagnetic map is matched according to the second inertia position after the preliminary correction; the geomagnetic map is a chart representing the magnetic field distribution of the earth's surface or a specific area, which shows the strength, direction, gradient, and magnetic declination angle of the earth's magnetic field; then, the central geomagnetic reference value of the center of each grid can be calculated according to the geomagnetic map.

[0084] Step a30: calculating the distribution probability of the real position falling into each grid according to the geomagnetic measurement value and the central geomagnetic reference value of each grid.

[0085] In the embodiment, the distribution probability of the real position falling into each grid is calculated according to the geomagnetic measurement value and the central geomagnetic reference value of each grid, including:

[0086] Step a301: calculating the geomagnetic normal distribution probability based on the geomagnetic measurement value and the central geomagnetic reference value of each grid, the geomagnetic normal distribution probability being used to represent the probability that the geomagnetic reference value corresponding to the grid is the geomagnetic measurement value when the real position falls into the grid.

[0087] In the embodiment, the calculation expression of the geomagnetic normal distribution probability is:

[0088] ;

[0089] In the formula, is the geomagnetic normal distribution probability, is the grid in the i-th row and the j-th column of the estimation area, g is the geomagnetic measurement value, i is the central geomagnetic reference value of the grid in the i-th row and the j-th column of the estimation area, j is the first coefficient, is the second coefficient, and e is the natural base. i j In the embodiment, the measurement error of the geomagnetic measurement value is normally distributed, the first coefficient is the mean value of the measurement error, and the second coefficient is the standard deviation of the measurement error, so the geomagnetic normal distribution probability can be determined according to the normal distribution function. Step a302: calculating the initial probability of each grid based on the number of grids.

[0090] In the embodiment, the calculation expression of the initial probability of each grid is:

[0091] Step a302: calculating the initial probability of each grid based on the number of grids.

[0092] In the embodiment, the calculation expression of the initial probability of each grid is: ​​

[0093] ;

[0094] wherein, is the initial probability of the grid in the i-th row and the j-th column of the estimated area, i is the total number of rows of the grid, j is the total number of columns of the grid, I and J are both odd numbers, I and J are both odd numbers, the second inertia position after the preliminary correction is located at the intersection of the grid lines. I J Step a303: calculating the output probability of each grid based on the initial probability and the geomagnetic normal distribution probability;

[0095] In this embodiment, the calculation expression of the output probability of each grid is as follows:

[0096]

[0097] ;

[0098] wherein, is the output probability of the grid in the i-th row and the j-th column of the estimated area, i is the grid in the i-th row and the j-th column of the estimated area, j is the total number of rows of the grid, is the total number of columns of the grid, i and j are both odd numbers, I is the geomagnetic normal distribution probability, J is the geomagnetic measurement value, I is the initial probability of the grid in the i-th row and the j-th column of the estimated area. J Step a304: calculating the evaluation index according to the output probability of each grid; judging whether the evaluation index reaches the preset threshold value, and taking the output probability of each grid as the distribution probability of the real position falling into each grid when the evaluation index reaches the preset threshold value. g wherein, the expression of the evaluation index is as follows: i j ;

[0099] wherein,

[0100] is the evaluation index, is the total area of the estimated area,

[0101] is the area of one grid.

[0102] ​​​​​​​​

[0103] Step a305: When the evaluation index does not reach the preset threshold, the output probability of each grid is used as the new initial probability of each grid, and the calculation of the output probability of each grid based on the initial probability and the geomagnetic normal distribution probability is repeated; the evaluation index is calculated according to the output probability of each grid; until the evaluation index reaches the preset threshold, the output probability of each grid corresponding to the evaluation index at the preset threshold is used as the distribution probability of the real position falling into each grid.

[0104] In this embodiment, the output probability of each grid is used as the new initial probability of each grid for iterative calculation, which can make the output probability of the grid converge to the true location, and the more likely that the location is the true location; when the evaluation index does not reach the preset threshold during iteration, the output probability of each grid is obtained.

[0105] Step a40: Determine the secondary correction amount based on the distance between the center of each grid and the initially corrected second inertial position and the probability distribution of the true position falling into each grid.

[0106] In this embodiment, after obtaining the secondary correction amount, the accurate second actual position of the marine exploration vehicle at the current depth can be obtained based on the initially corrected second inertial position and the secondary correction amount.

[0107] In this embodiment, the calculation expression for the second actual position of the ocean exploration vehicle at the current depth is:

[0108] ;

[0109] In the formula, This is the second actual location of the ocean exploration vehicle at its current depth. This is the second inertial position. For the prediction of the region's first i row and number j The distance between the center of the grid and the initially corrected second inertial position. For the error estimate change value, This is the second inertial position after preliminary correction. This is the second correction amount.

[0110] The present application determines the current depth of the marine exploration carrier through sonar data, and when the water depth is shallow, the satellite positioning position and the first inertial position are used to accurately calculate the first actual position of the marine exploration carrier at the current depth. During the calculation of the first actual position, a plurality of error estimation values are recorded, which are used to represent the error of the first inertial position in the positioning service. Then, the error change value is determined within a period of time. When the water depth is deep, the stability of the satellite signal is poor, and the error estimation change value is used as a reference factor for the correction of the second inertial position. Then, the secondary correction amount is determined through the geomagnetic measurement value. Finally, the second actual position of the marine exploration carrier at the current depth is calculated by combining the error estimation change value and the secondary correction amount, thereby improving the positioning accuracy of the marine exploration carrier in deep water.

[0111] Embodiment two

[0112] Figure 2 is a block diagram of a marine resource exploration positioning system based on inertial navigation provided by an embodiment of the present application, as Figure 2 shown, the present embodiment provides a marine resource exploration positioning system based on inertial navigation, which is used to realize the marine resource exploration positioning method based on inertial navigation of embodiment one, and the system comprises:

[0113] a depth determination module, configured to obtain sonar data of the marine exploration carrier, and determine the current depth of the marine exploration carrier according to the sonar data;

[0114] a first acquisition module, configured to, when the current depth of the marine exploration carrier is less than a preset depth, acquire a satellite positioning position and a first inertial position of the marine exploration carrier;

[0115] a first calculation module, configured to process the satellite positioning position and the first inertial position based on a filtering algorithm to obtain an error estimation value, correct the first inertial position with the error estimation value, and obtain a first actual position of the marine exploration carrier at the current depth;

[0116] an error recording module, configured to record a plurality of error estimation values within a preset time length, and determine an error estimation change value according to the plurality of error estimation values within the preset time length;

[0117] a second acquisition module, configured to, when the current depth of the marine exploration carrier reaches the preset depth, acquire a geomagnetic measurement value and a second inertial position;

[0118] a second calculation module, configured to preliminarily correct the second inertial position with the error estimation change value, determine a secondary correction amount based on the preliminarily corrected second inertial position and the geomagnetic measurement value, and determine a second actual position of the marine exploration carrier at the current depth based on the secondary correction amount and the preliminarily corrected second inertial position.

[0119] The present application determines the current depth of the marine exploration carrier through sonar data, and when the water depth is shallow, the satellite positioning position and the first inertial position are used to accurately calculate the first actual position of the marine exploration carrier at the current depth, and a plurality of error estimation values are recorded during the calculation of the first actual position, which are used to represent the error of the first inertial position in the positioning service, and then the error change value is determined in a period of time; when the water depth is deep, the stability of the satellite signal is poor, the error estimation change value is used as a reference factor for the correction of the second inertial position, and the second correction amount is determined through the geomagnetic measurement value, and finally the second actual position of the marine exploration carrier at the current depth is calculated by combining the error estimation change value and the second correction amount, so that the positioning accuracy of the marine exploration carrier in deep water can be improved.

[0120] Those skilled in the art will appreciate that embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage, etc.) containing computer usable program code.

[0121] The present application is described with reference to flowcharts and / or block diagrams according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as a combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, so that the instructions executed by the computer or other programmable data processing apparatus produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in a flow or a plurality of flows and / or blocks Figure 1 The functions specified in a flow or a plurality of flows and / or blocks

[0122] The above is only an embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the scope of claims of the present application.

Claims

1. A method for positioning in marine resource exploration based on inertial navigation, characterized in that, The method comprises: acquiring sonar data of the marine exploration carrier, and determining a current depth at which the marine exploration carrier is located according to the sonar data; when the current depth at which the marine exploration carrier is located is less than a preset depth, acquiring a satellite positioning position and a first inertial position of the marine exploration carrier; processing the satellite positioning position and the first inertial position based on a filtering algorithm to obtain an error estimation value, correcting the first inertial position with the error estimation value to obtain a first actual position of the marine exploration carrier at the current depth; recording a plurality of error estimation values within a preset time length, determining an error estimation change value according to the plurality of error estimation values within the preset time length; fitting the plurality of error estimation values to obtain an error function, the error function being used to represent a change of the error estimation value with an increase of a positioning time length; and calculating the error estimation change value according to a loss time length of a satellite signal and the error function; after the current depth at which the marine exploration carrier is located reaches the preset depth, acquiring a geomagnetic measurement value and a second inertial position; preliminarily correcting the second inertial position with the error estimation change value, determining a secondary correction amount based on the second inertial position after the preliminary correction and the geomagnetic measurement value, and determining a second actual position of the marine exploration carrier at the current depth based on the secondary correction amount and the second inertial position after the preliminary correction; determining the secondary correction amount based on the second inertial position after the preliminary correction and the geomagnetic measurement value, comprising: constructing an estimated area based on the second inertial position after the preliminary correction; grid-dividing the estimated area, determining a center geomagnetic reference value of each grid and a distance between the center of each grid and the second inertial position after the preliminary correction; calculating a geomagnetic normal distribution probability based on the geomagnetic measurement value and the center geomagnetic reference value of each grid, the geomagnetic normal distribution probability being used to represent a probability that the center geomagnetic reference value of a grid corresponding to a true position falls within the geomagnetic measurement value when the true position falls within the grid; calculating an initial probability of each grid based on the number of grids; calculating an output probability of each grid based on the initial probability and the geomagnetic normal distribution probability; calculating an evaluation index according to the output probability of each grid; determining whether the evaluation index reaches a preset threshold value; when the evaluation index reaches the preset threshold value, taking the output probability of each grid as a distribution probability of the true position falling within each grid; when the evaluation index does not reach the preset threshold value, taking the output probability of each grid as a new initial probability of each grid, and repeatedly performing the calculation of the output probability of each grid based on the initial probability and the geomagnetic normal distribution probability; calculating an evaluation index according to the output probability of each grid; until the evaluation index reaches the preset threshold value, taking the output probability of each grid corresponding to the evaluation index when the preset threshold value is reached as the distribution probability of the true position falling within each grid; determining the secondary correction amount according to the distance between the center of each grid and the second inertial position after the preliminary correction and the distribution probability of the true position falling within each grid; the calculation expression of the output probability of each grid is: ； In the formula, For the prediction of the region's first i row and number j The output probability of the grid of columns, For the prediction of the region's first i row and number j Column grid, I The total number of rows in the grid. J The total number of columns in the grid. I and J All are odd numbers. The probability is a geomagnetic normal distribution. g These are geomagnetic measurements. For the prediction of the region's first i row and number j The initial grid probabilities of the column, where, ; the calculation expression of the geomagnetic normal distribution probability is: ； wherein is a geomagnetic normal distribution probability, is a first coefficient, i is a second coefficient, and e is the natural base number. j is a grid of the estimated area, g is a geomagnetic measurement value, is a center geomagnetic reference value of the grid of the estimated area, i is a grid of the estimated area, g is a geomagnetic measurement value, j is a center geomagnetic reference value of the grid of the estimated area, is a first coefficient, is a second coefficient, and e is the natural base number. the calculation expression of the second actual position of the marine exploration carrier at the current depth is: ； wherein is a second actual position of the marine exploration vehicle at the current depth, is a second inertial position, is a first i is a second j is a distance between the center of the grid of the first row and the first column and the second inertial position after the preliminary correction, is an error estimation change, is a second correction amount.

2. The inertial navigation-based positioning method for ocean resource exploration according to claim 1, characterized in that, The filter algorithm is a Kalman filter algorithm, the satellite positioning position and the first inertial position are processed based on the filter algorithm to obtain an error estimation value, the first inertial position is corrected based on the error estimation value to obtain a first actual position of the marine exploration carrier at the current depth, and the method comprises the following steps: The first inertial position is taken as an observation value of the Kalman filter algorithm, and the satellite positioning position is taken as a state value of a Kalman filter model to predict an error estimation value of an error state value; The first inertial position is corrected based on the error estimation value of the error state value to obtain a corrected first inertial position, and the corrected first inertial position is taken as the first actual position of the marine exploration carrier at the current depth.

3. The inertial navigation-based positioning method for ocean resource exploration according to claim 1, wherein, The marine exploration carrier is provided with an inertial measurement unit, the first inertial position and the second inertial position are determined by the inertial measurement unit, and the inertial measurement unit comprises an accelerometer and a gyroscope, the accelerometer is used to collect acceleration values of the marine exploration carrier in real time, and the gyroscope is used to collect angular velocity values of the marine exploration carrier in real time.

4. The inertial navigation-based positioning method for ocean resource exploration according to claim 1, wherein, The marine exploration carrier is provided with a transmitting sonar probe and a plurality of receiving sonar probes, and the sonar data comprises second echo signals received by the receiving sonar probes; The sonar data of the marine exploration carrier is acquired, and the current depth of the marine exploration carrier is determined according to the sonar data, which comprises the following steps: The current attitude of the marine exploration carrier is acquired, and the height difference between each receiving sonar probe and the transmitting sonar probe in the vertical direction is determined according to the current attitude; The second echo signals received by each receiving sonar probe are filtered to obtain a plurality of processed second echo signals; The detection depths of the receiving sonar probes are calculated according to the processed second echo signals of the receiving sonar probes and the corresponding receiving interval lengths; The current depth of the marine exploration carrier is determined according to the detection depths of the receiving sonar probes and the height differences between the receiving sonar probes and the transmitting sonar probe in the vertical direction.

5. An inertial navigation based positioning system for marine resource exploration, the system being configured to implement the inertial navigation based positioning method for marine resource exploration according to any one of claims 1-4, characterized in that, The system comprises: a depth determination module, which is used to acquire sonar data of a marine exploration carrier and determine a current depth of the marine exploration carrier according to the sonar data; a first acquisition module, which is used to acquire a satellite positioning position and a first inertial position of the marine exploration carrier when the current depth of the marine exploration carrier is less than a preset depth; a first calculation module, which is used to process the satellite positioning position and the first inertial position based on a filter algorithm to obtain an error estimation value, correct the first inertial position based on the error estimation value, and obtain a first actual position of the marine exploration carrier at the current depth; an error recording module, which is used to record a plurality of error estimation values within a preset time length and determine an error estimation change value according to the plurality of error estimation values within the preset time length; a second acquisition module, which is used to acquire a geomagnetic measurement value and a second inertial position when the current depth of the marine exploration carrier reaches the preset depth. The second computing module is configured to preliminarily correct the second inertial position by the error estimation change value, determine a second correction quantity based on the preliminarily corrected second inertial position and the geomagnetic measurement value, and determine the second actual position of the ocean exploration carrier at the current depth based on the second correction quantity and the preliminarily corrected second inertial position.

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