Post-processing method and device for AUV positioning data, medium and program product

Abstract

The invention discloses a post-processing method and device for AUV positioning data, a medium and a program product. The method comprises the following steps: acquiring a first measuring point sequence and a second measuring point sequence of the AUV; wherein the first measuring point sequence is a positioning data set determined by a strapdown inertial navigation system, and the second measuring point sequence is a positioning data set determined by an ultra-short baseline underwater positioning system; performing jump point deletion on the second measuring point sequence, performing trajectory fitting, and determining a virtual control point based on a fitting trajectory; constructing a measurement section based on two adjacent virtual control points, and matching the measurement section with each first measurement point in the first measurement point sequence according to time; and for each measurement section, correcting the first measurement point in the measurement section according to the virtual control point to obtain a corrected measurement point, and determining a correction track of the AUV based on each corrected measurement point. According to the technical scheme, the correction of the AUV positioning data is realized by constructing the virtual control point, and the precision of the AUV positioning data is improved, so that the accuracy and applicability of an underwater task are met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of data processing, and in particular to an AUV positioning data post-processing method, device, medium and program product. BACKGROUND

[0002] Underwater high-precision navigation positioning technology is the key to the successful execution of underwater tasks by an autonomous underwater vehicle (AUV). A strap-down inertial navigation system (SINS) has been widely used due to its complete autonomy, concealment and comprehensive output of navigation information. However, SINS can only output high-precision navigation information for a short time, and the positioning error will gradually diverge with the increase of the navigation distance, resulting in error accumulation and poor absolute accuracy.

[0003] Currently, an ultra short baseline positioning system (USBL) is usually carried on the AUV to assist the SINS in AUV positioning or monitoring. The USBL is a base array installed on a mother ship and a beacon carried on the AUV, which sends and receives acoustic signals through the acoustic array and obtains the absolute position of the AUV based on the distance method. However, due to the working principle of the USBL and the error of the underwater acoustic environment, the USBL has a long positioning time interval, a large number of wild values in the positioning data, and even a large number of continuous observation data with poor positioning accuracy, thereby affecting the accuracy of the AUV positioning data.

[0004] Therefore, how to provide a technical solution capable of improving the accuracy of AUV positioning data is a technical problem to be solved by those skilled in the art. SUMMARY

[0005] The present application provides an AUV positioning data post-processing method, device, medium and program product, which constructs a virtual control point by utilizing the characteristics of high azimuth angle accuracy of the first measuring point and high absolute accuracy of the second measuring point, so as to correct the AUV positioning data and improve the accuracy of the AUV positioning data, thereby meeting the accuracy and applicability of underwater tasks.

[0006] According to an aspect of the present application, an AUV positioning data post-processing method is provided, which comprises: obtaining a first measuring point sequence and a second measuring point sequence of the AUV in a target time period; wherein the first measuring point sequence is a positioning data set of a first measuring point determined by a strap-down inertial navigation system carried on the AUV, and the second measuring point sequence is a positioning data set of a second measuring point determined by an ultra short baseline underwater positioning system carried on the AUV; fitting a trajectory according to the second sequence of measurement points, and determining at least two virtual control points based on the fitted trajectory; constructing a measurement section based on two adjacent virtual control points, and matching the measurement section with each first measurement point in the first sequence of measurement points according to time to determine a first measurement point corresponding to the measurement section; for each measurement section, correcting the first measurement points in the measurement section according to the virtual control points to obtain corrected measurement points, and determining a corrected trajectory of the AUV based on the corrected measurement points.

[0007] According to another aspect of the present application, an electronic device is provided, which comprises at least one processor, and a memory connected to the at least one processor in communication; wherein the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to perform the post-processing method of AUV positioning data according to any embodiment of the present application.

[0008] According to another aspect of the present application, a computer readable storage medium is provided, which stores computer instructions for enabling a processor to implement the post-processing method of AUV positioning data according to any embodiment of the present application when executed by the processor.

[0009] According to another aspect of the present application, a computer program product is provided, which comprises a computer program for implementing the post-processing method of AUV positioning data according to any embodiment of the present application when executed by a processor.

[0010] The technical solution provided by the present application comprises the following steps: obtaining a first sequence of measurement points and a second sequence of measurement points of an AUV; wherein the first sequence of measurement points is a set of positioning data determined by a strapdown inertial navigation system, and the second sequence of measurement points is a set of positioning data determined by an ultra-short baseline underwater positioning system; fitting a trajectory according to the second sequence of measurement points, and determining at least two virtual control points based on the fitted trajectory; constructing a measurement section based on two adjacent virtual control points, and matching the measurement section with each first measurement point in the first sequence of measurement points according to time; for each measurement section, correcting the first measurement points in the measurement section according to the virtual control points to obtain corrected measurement points, and determining a corrected trajectory of the AUV based on the corrected measurement points. The technical solution constructs virtual control points to correct the positioning data of the AUV, improves the accuracy of the positioning data of the AUV, and thus meets the accuracy and applicability of underwater tasks.

[0011] It should be appreciated that the description set forth in this section is not intended to identify key or essential features of the application, and the scope of the application is not to be limited to any of the features set forth in this section. Other features, aspects, and advantages of the application will become apparent from a review of the following description. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative effort.

[0013] Figure 1 A flow chart of an AUV positioning data post-processing method provided for the first embodiment of the present application.

[0014] Figure 2 An AUV track line layout schematic diagram provided for the first embodiment of the present application.

[0015] Figure 3 A flow chart of an AUV positioning data post-processing method provided for the second embodiment of the present application.

[0016] Figure 4 A flow chart of an AUV positioning data post-processing method provided for the third embodiment of the present application.

[0017] Figure 5 An AUV observation track schematic diagram provided for the third embodiment of the present application.

[0018] Figure 6 An AUV fitting track schematic diagram provided for the third embodiment of the present application.

[0019] Figure 7 A matching point distance deviation schematic diagram provided for the third embodiment of the present application.

[0020] Figure 8 An AUV correction measurement point schematic diagram provided for the third embodiment of the present application.

[0021] Figure 9 An AUV correction measurement point and detection point deviation schematic diagram provided for the third embodiment of the present application.

[0022] Figure 10 A structure schematic diagram of an AUV positioning data post-processing method device for implementing the embodiments of the present application. DETAILED DESCRIPTION

[0023] In the following, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application, so that those skilled in the art can better understand the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present application.

[0024] It should be noted that the terms "first", "second", "correction", "other" and the like in the description, claims, and drawings of the present application are used to distinguish similar objects, and do not necessarily have to be used to describe a particular order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0025] Embodiment one Figure 1 A flowchart of an AUV positioning data post-processing method provided by Embodiment one of the present application is provided. The present embodiment can be applied to the post-processing of acquired AUV positioning data. The method can be executed by an AUV positioning data post-processing device, which can be realized in the form of hardware and / or software, and can be configured in a device with data processing capability. As shown in Figure 1 The method includes the following steps.

[0026] S110, acquiring a first measurement point sequence and a second measurement point sequence of the AUV in a target time period.

[0027] The first measurement point sequence is a set of positioning data of the first measurement point determined by a strapdown inertial navigation system carried on the AUV, and the second measurement point sequence is a set of positioning data of the second measurement point determined by an ultra-short baseline underwater positioning system carried on the AUV.

[0028] During AUV operations, the strapdown inertial navigation system (SINS) onboard the AUV measures the angular and linear motion of the AUV relative to inertial space using inertial sensors. A computer then continuously integrates and transforms the measurement data to calculate the AUV's attitude, velocity, and position in real time. The azimuth information determined by this system has high absolute accuracy, resulting in accurate timing during sharp turns and approximately constant azimuth error during straight-line operations. However, since all navigation parameters are obtained based on integration, the small, inherent constant biases and random noise of the sensors accumulate over time after integration, leading to a continuous increase in positioning error.

[0029] The ultra-short baseline underwater positioning system (ULS) consists of an acoustic array mounted on a mother ship and a beacon mounted on an AUV. It transmits and receives acoustic signals via the acoustic array, determines the relative position of the array and the beacon using a distance method, and then determines the absolute position of the AUV through coordinate transformation. While the positioning data it provides is highly accurate, the data has many jumps and some observation points are continuously unstable.

[0030] The target time period can be a single operation of the AUV, or a time period selected according to actual needs. The first measurement point sequence can be a set of positioning data from multiple first measurement points calculated by the strapdown inertial navigation system in a time sequence within the target time period. This positioning data may include timestamps, longitude, latitude, depth, east coordinates, north coordinates, velocity, attitude, positioning accuracy, etc. The second measurement point sequence can be a set of positioning data from multiple second measurement points determined by the ultra-short baseline underwater positioning system in a time sequence within the target time period. This positioning data may include timestamps, AUV relative position, AUV absolute position, depth, mother ship information, etc.

[0031] Specifically, after the AUV operation is completed and the vessel is recovered, the first measurement point sequence can be read through the AUV's built-in memory, and the second measurement point sequence can be exported through the mother ship's underwater positioning system software.

[0032] S120. Perform trajectory fitting based on the second measurement point sequence to obtain a fitted trajectory, and determine at least two virtual control points based on the fitted trajectory.

[0033] Understandably, the second measurement point sequence determined by the ultra-short baseline underwater positioning system has many jump points and some continuous but unstable observation points, although most will fluctuate around the actual location. Therefore, this application processes the second measurement point sequence and determines more accurate measurement points from it as virtual control points to correct the first measurement point sequence and improve the accuracy of AUV positioning data.

[0034] In this application, a trajectory fitting can be performed on the sequence of second measuring points to reconstruct a series of discrete second measuring points into a continuous and smooth trajectory curve. Specifically, the latitude and longitude of the second measuring points in the geodetic coordinate system, or the northeast coordinates of the second measuring points in the plane projected coordinate system, can be used to fit the trajectory using methods such as polynomial fitting, spline fitting, sliding window fitting, or recursive fitting based on Kalman filtering to obtain the fitted trajectory.

[0035] Virtual control points can be trajectory points in the fitted trajectory that correspond to the observation times of the second measurement point sequence. For example, the second measurement point sequence... The observation times are as follows: The fitted trajectory obtained after fitting the second measurement point sequence is a curve. In the curve Find the observation time on the top Corresponding trajectory points .

[0036] Before obtaining the fitted trajectory by fitting the trajectory based on the second measurement point sequence, outlier deletion can be performed on the second measurement point sequence to remove second measurement points that significantly deviate from the normal range.

[0037] In some embodiments, optionally, the second measuring point sequence includes at least a time series, an east coordinate series, and a north coordinate series of the second measuring point; correspondingly, the trajectory fitting based on the second measuring point sequence to obtain a fitted trajectory includes: fitting the time series and the east coordinate series to obtain a first fitted curve; fitting the time series and the north coordinate series to obtain a second fitted curve; and determining the fitted trajectory based on the first fitted curve, the second fitted curve, and the time series.

[0038] Among them, the east and north coordinates can be used to represent the location of ground points in a Cartesian coordinate system, which is a two-dimensional Cartesian coordinate system established by projecting the Earth's surface onto a plane. The second measurement point sequence includes a time series. East coordinate sequence and the North Coordinate Sequence In this context, the elements in the time series, the eastern coordinate series, and the northern coordinate series correspond sequentially, that is, in The second measuring point observed at time [time] The track coordinates are , Indicates the second measuring point The eastern coordinates, Indicates the second measuring point The north coordinates.

[0039] Specifically, the moving least squares method can be used to fit the second measurement point sequence. The function model can be a quadratic polynomial. Moving least squares fitting is performed on the eastern coordinate series and the time series to obtain the first fitting curve, and moving least squares fitting is performed on the eastern coordinate series and the time series to obtain the second fitting curve. Finally, based on the time values ​​in the time series, the corresponding coordinate values ​​are determined in the first and second fitting curves, and the coordinate values ​​are paired to obtain the coordinates of the fitted trajectory points. That is, the first fitting curve is... The second fitted curve is Determine the first fitted curve Medium time value The coordinates are And determine the second fitted curve Medium time value The coordinates are and time value Pair the coordinates of time to obtain .

[0040] By fitting the east and north coordinates separately, the accuracy of the measurement point coordinates determined by USBL was improved.

[0041] In some embodiments, optionally, the first measuring point sequence includes at least the azimuth sequence of the first measuring point; correspondingly, after obtaining the fitted trajectory by fitting the trajectory according to the second measuring point sequence, the method further includes: determining the trajectory attributes of the AUV according to the azimuth sequence of the first measuring point; wherein, the trajectory attributes include turning segments and straight segments; and deleting trajectory segments in the fitted trajectory that are different from the trajectory attributes.

[0042] In projects such as seabed topographic mapping or underwater archaeology, AUV tracks are often laid out as multiple parallel straight lines. For example... Figure 2 As shown, the AUV travels from one end of a survey line to the other, and then turns to an adjacent survey line to continue its work. The azimuth angles of the two adjacent survey lines differ by 180°.

[0043] The azimuth angle determined by SINS has high absolute accuracy. Therefore, the azimuth angle and the rate of change of the azimuth angle determined by SINS can be used to determine whether the AUV is currently traveling in a straight line or turning. Especially when the AUV is making a sharp turn, the timing of the turn can be considered accurate, thereby determining the trajectory attributes of the AUV.

[0044] Specifically, if the AUV track's trajectory attribute shows a straight line segment, while the fitted trajectory's trajectory attribute shows a turning segment, then that trajectory segment data can be deleted; conversely, if the AUV track's trajectory attribute shows a turning segment, while the fitted trajectory's trajectory attribute shows a straight line segment, then that trajectory segment data can be deleted. Furthermore, if the second measurement point determined by USBL is relatively divergent before fitting, and the fitted trajectory after fitting is serpentine, then all trajectory segment data can be deleted.

[0045] Based on this, the virtual control points determined from the fitted trajectory will be closer to the actual trajectory points of the AUV, thereby improving the accuracy of subsequent correction of the first measurement point using virtual control points.

[0046] S130. Construct a measurement segment based on two adjacent virtual control points, and match the measurement segment with each first measurement point in the first measurement point sequence according to time to determine the first measurement point corresponding to the measurement segment.

[0047] It is understandable that the data sampling frequency determined by SINS is higher, while the data sampling frequency determined by USBL is lower. Therefore, this application constructs a measurement segment by sequentially arranging adjacent virtual control points according to time sequence. For example, according to time sequence, let the first measurement point be... The observation time is Virtual control point is The observation time is Two adjacent virtual control points are used to construct a measurement segment. , , ..., , ..., .

[0048] Specifically, the time period to be matched can be determined first based on the observation time corresponding to the two virtual control points within the measurement segment. Then, the first measurement point contained in the first measurement point sequence within the time period to be matched can be determined as the first measurement point corresponding to the measurement segment. Alternatively, two first measurement points corresponding to two virtual control points can be determined first, and other first measurement points between these two first measurement points can also be taken as the first measurement points corresponding to the measurement segment.

[0049] Because the AUV travels slowly on the seabed, while the sampling frequency of the first measuring point is high, the time difference between the first measuring point and the virtual control point can be set to be within 0.1 seconds for matching. That is, when At that time, it is assumed that the first measuring point and the virtual control point are matched, and the serial number of the first measuring point and the serial number of the virtual control point are recorded. For example, the first measuring point... With virtual control points Matching, first measurement point With virtual control points If it matches, then it is related to the test segment. The first matching measurement point is .

[0050] S140. For each of the measurement segments, the first measurement point within the measurement segment is corrected according to the virtual control point to obtain a corrected measurement point, and the correction trajectory of the AUV is determined based on each of the corrected measurement points.

[0051] The virtual control point is a reference point determined by fitting the second measurement point sequence, and its coordinate position is relatively accurate. In this application, the first measurement point in the measurement segment can be corrected sequentially using the first and last virtual control points within the measurement segment to obtain the corrected measurement point.

[0052] Specifically, a calibration model can be established based on the coordinates of the first and last virtual control points within the measurement section. The calibration model is then used to calibrate the first measurement point to obtain the calibrated measurement point. The calibration method may include one or more of translation calibration, rotation calibration, and scaling calibration.

[0053] Furthermore, the calibration trajectory can be obtained by connecting the calibration points corrected by the first calibration point. For example, for simple trajectories, the calibration trajectory can be obtained by connecting the calibration points using interpolation or by fitting the calibration points using a fitting method. For complex trajectories, the calibration trajectory can be obtained by connecting the calibration points using a parametric fitting method.

[0054] This invention provides a post-processing method for AUV positioning data. The method involves acquiring a first measurement point sequence and a second measurement point sequence for the AUV. The first measurement point sequence is a positioning data set determined by a strapdown inertial navigation system, and the second measurement point sequence is a positioning data set determined by an ultra-short baseline underwater positioning system. A trajectory is fitted based on the second measurement point sequence to obtain a fitted trajectory, and virtual control points are determined based on the fitted trajectory. Measurement segments are constructed based on two adjacent virtual control points, and each measurement segment is matched with each first measurement point in the first measurement point sequence according to time. For each measurement segment, the first measurement points within the segment are corrected based on the virtual control points to obtain corrected measurement points, and the corrected trajectory of the AUV is determined based on each corrected measurement point. This technical solution improves the accuracy of AUV positioning data by constructing virtual control points to correct the AUV positioning data, thereby meeting the accuracy and applicability requirements of underwater missions.

[0055] Example 2 Figure 3 This is a flowchart of a post-processing method for AUV positioning data provided in Embodiment 2 of this application. This embodiment is an optimization based on the above embodiment, specifically optimizing the process of correcting the first measuring point within the measuring segment according to the virtual control point. Figure 3 As shown, the method in this embodiment specifically includes the following steps.

[0056] S210. Obtain the first measurement point sequence and the second measurement point sequence of the AUV within the target time period. The first measurement point sequence is a set of positioning data for the first measurement point determined by the strapdown inertial navigation system mounted on the AUV, and the second measurement point sequence is a set of positioning data for the second measurement point determined by the ultra-short baseline underwater positioning system mounted on the AUV.

[0057] S220. Perform trajectory fitting based on the second measurement point sequence to obtain a fitted trajectory, and determine at least two virtual control points based on the fitted trajectory.

[0058] S230. Construct a measurement segment based on two adjacent virtual control points, and match the measurement segment with each first measurement point in the first measurement point sequence according to time to determine the first measurement point corresponding to the measurement segment.

[0059] S240. For each of the measured segments, the translation deviation is determined based on the first virtual control point within the measured segment and the first measured point that matches the first virtual control point.

[0060] The translation deviation can be the systematic deviation between the virtual control point and the first measuring point within the measurement section in the translation direction, used to perform translation processing on the first measuring point. In this application, for ease of calculation, the deviation between the first virtual control point and the first measuring point matching the first virtual control point on each coordinate axis is taken as the translation deviation of each first measuring point within the measurement section.

[0061] Specifically, assuming virtual control points With the first measuring point match, The coordinates are , The coordinates are Virtual control point With the first measuring point Matching, and segment testing The corresponding first measuring point is Then the translation deviation can be used and The difference in planar coordinates is used to represent: ; In the formula, Represents virtual control points With the first measuring point Translation deviation on the eastern coordinate system Represents virtual control points With the first measuring point Translation deviation on the north coordinate.

[0062] S250. Determine the azimuth deviation based on the virtual control point within the measurement section and the first measurement point.

[0063] The azimuth deviation can be the deviation between the virtual control point and the first measuring point in the trajectory heading angle within the measurement segment, used to perform rotation processing on the first measuring point. In this application, the difference between the azimuth angle of the line segment formed by the two virtual control points and the azimuth angle of the line segment formed by the first and last two first measuring points can be used as the azimuth deviation.

[0064] Specifically, assuming virtual control points With the first measuring point match, The coordinates are , The coordinates are Virtual control point With the first measuring point match, The coordinates are , The coordinates are , and the measurement section The corresponding first measuring point is ,but line segment and Angle between line segments As an azimuth deviation: .

[0065] S260. Based on the translation deviation, the first first measuring point in the measuring segment is corrected to obtain a corrected measuring point; and based on the translation deviation and the azimuth deviation, the other first measuring points in the measuring segment are corrected to obtain corrected measuring points.

[0066] As can be seen from the azimuth deviation calculation formula in step S250, there is no azimuth deviation at the first measuring point in the measuring section. Therefore, the first measuring point in the measuring section only needs to be corrected by translation deviation, while the other first measuring points in the measuring section are corrected by translation deviation and azimuth deviation.

[0067] For the first measuring point within the measuring section, its correction measuring point can be determined using the following formula: ; In the formula, This indicates the east coordinates of the correction measuring point corresponding to the first measuring point. This indicates the north coordinates of the calibration measuring point corresponding to the first measuring point.

[0068] For the first measuring point other than the first measuring point in the measuring section, the coordinates can be translated based on the translation deviation, and then the coordinates after translation can be rotated based on the azimuth deviation to eliminate the azimuth deviation.

[0069] In some embodiments, optionally, correcting other first measuring points within the measuring segment based on the translational deviation and the azimuth deviation to obtain corrected measuring points includes: correcting the first measuring points within the measuring segment using the following formula to obtain corrected measuring points: ; In the formula, Indicates the first section within the measurement segment The east coordinates of the calibration measuring point corresponding to the first measuring point , Indicates the first section within the measurement segment The north coordinates of the calibration measuring point corresponding to the first measuring point This indicates the east coordinates of the first measuring point within the measurement section. This indicates the north coordinates of the first measuring point within the measurement section. This indicates the translation deviation of the east coordinate. This indicates the translation deviation of the north coordinate. Indicates the distance from the first measurement point to the... The azimuth angle of the line segment between the first measuring points Indicates azimuth deviation. Indicates the first measuring point and the first measuring point within the measuring section. The distance between the first measuring points This represents the distance between the first and last measuring points within the measured section. This indicates the distance between two adjacent virtual control points within the measurement section.

[0070] Because the first measuring point calculated by SINS has accumulated errors, the distance between the first and last measuring points in the measuring segment is inconsistent with the distance between the first and last virtual control points. Therefore, this application uses the first measuring point in the measuring segment as the base point and distributes the distance difference of other first measuring points proportionally, i.e., stretching processing.

[0071] Specifically, assuming virtual control points With the first measuring point match, The coordinates are , The coordinates are Virtual control point With the first measuring point match, The coordinates are , The coordinates are , and the measurement section The corresponding first measuring point is The distance between the first and last virtual control points within the measured section is... : ; Distance between the first and last measuring points within the measuring section : ; Other first measuring points within the measuring section and the first measurement point Distance between : ; The first measuring point within the measuring section To other first measurement points azimuth : .

[0072] In conclusion, Used to indicate other first measurement points The difference is assigned distance.

[0073] In some embodiments, optionally, before determining the correction trajectory of the AUV based on each of the correction measurement points, the method further includes: for a first measurement point before the first virtual control point or after the last virtual control point, correcting the first measurement point according to the translation deviation, and determining a correction measurement point corresponding to the first measurement point.

[0074] It is understandable that, in addition to the first measuring point included within the measuring segment, there may also be a first measuring point before the first virtual control point or after the last virtual control point. For such first measuring points, the above steps cannot be used to calculate the azimuth deviation and stretching within that segment. Moreover, for the first measuring point before the first virtual control point, if the time interval between the first and second pairs of matching points is very short, the azimuth deviation calculated by the first and second pairs of matching points will have relatively low accuracy. For the first measuring point after the last virtual control point, if the azimuth deviation and stretching of the previous segment of virtual control points are used for correction, it will be greatly affected by the distance and time interval between control points, and the corrected data may be severely distorted.

[0075] Therefore, this application sets the portion before the first virtual control point as a measurement segment and the portion after the last virtual control point as a measurement segment, and corrects the first measurement point within the measurement segment only by translation deviation.

[0076] Specifically, for the first measurement point before the first virtual control point, let's assume the first measurement point before the first virtual control point is... Virtual control point With the first measuring point Matching, then virtual control point With the first measuring point The difference in plane coordinates is : .

[0077] Based on the difference in planar coordinates, the first measuring point is... Perform a translation, for example, the first measuring point. Correction measurement point coordinates for: .

[0078] The first measurement point after the last virtual control point, assuming the first measurement point after the last virtual control point is... Virtual control point With the first measuring point Matching, then virtual control point With the first measuring point The difference in plane coordinates is : .

[0079] Based on the difference in planar coordinates, the first measuring point is... Perform a translation, for example, the first measuring point. Correction measurement point coordinates for: .

[0080] S270. Determine the correction trajectory of the AUV based on each of the correction measurement points.

[0081] This invention provides a post-processing method for AUV positioning data, particularly optimizing the correction process for the first measuring point. The method involves determining the translational deviation based on the first virtual control point within the measurement segment and the first measuring point matching it; determining the azimuth deviation based on the virtual control point and the first measuring point within the measurement segment; correcting the first measuring point within the measurement segment based on the translational deviation to obtain a corrected measuring point; and correcting other first measuring points within the measurement segment based on the translational deviation and the azimuth deviation to obtain corrected measuring points. This technical solution, based on the virtual control point, performs translational and rotational processing on the first measuring point to correct the AUV positioning data, improving its accuracy and thus meeting the accuracy and applicability requirements of underwater missions.

[0082] Example 3 Figure 4This is a flowchart of a post-processing method for AUV positioning data provided in Embodiment 2 of this application. This embodiment is based on the above embodiment but with optimizations, specifically optimizing the process for determining the correction trajectory. Figure 4 As shown, the method in this embodiment specifically includes the following steps.

[0083] S310. Obtain the first measurement point sequence and the second measurement point sequence of the AUV within the target time period. The first measurement point sequence is a set of positioning data for the first measurement point determined by the strapdown inertial navigation system mounted on the AUV, and the second measurement point sequence is a set of positioning data for the second measurement point determined by the ultra-short baseline underwater positioning system mounted on the AUV.

[0084] S320. Perform trajectory fitting based on the second measurement point sequence to obtain a fitted trajectory, and determine at least two virtual control points based on the fitted trajectory.

[0085] S330. Construct a measurement segment based on two adjacent virtual control points, and match the measurement segment with each first measurement point in the first measurement point sequence according to time to determine the first measurement point corresponding to the measurement segment.

[0086] S340. For each of the aforementioned measurement segments, the first measurement point within the measurement segment is corrected according to the virtual control point to obtain the corrected measurement point.

[0087] S350. Based on a preset time window, the sliding least squares method is used to fit each of the calibration measurement points to determine the calibration trajectory of the AUV.

[0088] Understandably, due to the influence of the virtual control point time interval, within the same measurement section, the smaller the time interval between two virtual control points, the larger the calculated azimuth error will be for the same point accuracy. Specifically, let the virtual control points within the measurement section... arrive The azimuth is The azimuth error is ,but: ; In the formula, , .

[0089] Assumption , , and The errors are independent of each other. The standard deviations are all ,but: .

[0090] set up for arrive The planar distance between them, right and The derivative is as follows: .

[0091] According to the first-order error propagation formula, we can obtain: ; Substituting into the relevant formula, we get: .

[0092] Therefore, we can obtain .

[0093] Assuming AUV in Click The motion between the points is uniform, with a velocity of... After time After AUV from Point movement to Point, that is Click The planar distance between the points is: .but Relative to the time difference between two points The function is .

[0094] As can be seen from the above formula, the shorter the time difference and the smaller the distance between two adjacent virtual control points within a measurement section, the greater the azimuth error. Therefore, the calculated AUV correction measurement point position will be offset. Furthermore, because the time intervals between measurement sections vary, a broken line phenomenon is prone to occur.

[0095] Therefore, this application sets a certain time window based on the data to fit the calibration measurement points using the sliding least squares method, thereby obtaining the calibration trajectory of the AUV.

[0096] This invention provides a post-processing method for AUV positioning data, particularly optimizing the determination of the correction trajectory. By using a preset time window, the moving least squares method is applied to fit each correction measurement point to determine the AUV's correction trajectory. This technical solution improves the smoothness of the AUV correction trajectory by setting a preset time window and limiting the range of fitted data, thereby meeting the applicability requirements for underwater missions.

[0097] Based on the above embodiments, this application utilizes measured data from an AUV used in an underwater resource survey project in a certain sea area for verification. The AUV operating in this sea area was equipped with an ultra-short baseline underwater positioning system, which simultaneously recorded USBL beacon positioning data on the mother ship.

[0098] Figure 5 This application provides an AUV observation track map in Embodiment 3, such as... Figure 5 As shown, the light gray dashed lines represent the track lines determined by the strapdown inertial navigation system, and the dark gray dotted lines represent the track lines determined by the ultra-short baseline underwater positioning system. The track diagram reveals a significant deviation between the first measurement point position determined by the strapdown inertial navigation system and the second measurement point position determined by the ultra-short baseline underwater positioning system. The first measurement point exhibits relatively stable bearing, while the second measurement point shows data jumps and discontinuous, unstable positioning points. Therefore, jump points in the second measurement point are deleted, as are portions of the second measurement point with unstable bearing angles or bearing angles significantly deviating from the first measurement point at the same time, or consecutive second measurement points.

[0099] A 20-second time window was used to perform sliding least squares fitting on the second measurement point sequence. The processed fitted trajectory is as follows: Figure 6 As shown. The virtual control points in the fitted trajectory are matched with the first measurement point according to time. Figure 7 This is a schematic diagram illustrating a matching point distance deviation provided in Embodiment 3 of this application. Figure 7 As shown, the matching point number is the virtual control point number, and the distance deviation of a group of points is large at the same time.

[0100] To facilitate better data comparison, the processed second measuring point is divided into two parts. One part is used to correct the first measuring point to obtain a corrected measuring point, which is set as a virtual control point. The other part is used to compare with the corrected measuring point to determine the correction accuracy of the measuring point, which is set as a detection point. Figure 8 This is a schematic diagram of an AUV calibration measurement point provided in Embodiment 3 of this application. Figure 8 As shown, the light gray lines represent calibration measurement points, and the dark gray dots represent virtual control points.

[0101] The positioning deviation is calculated by time matching the calibration measuring point and the detection point. The deviation is as follows: Figure 9 As shown. By comparison Figure 7 and Figure 9 It can be seen that the AUV positioning data post-processing method based on virtual control points in this application can greatly improve the accuracy of AUV measurement point positioning, provide accurate positioning for subsequent underwater missions, and ensure the reliability and applicability of survey data observed by AUVs.

[0102] Example 4 Figure 10A schematic diagram of the structure of a device 10 that can be used to implement embodiments of this application is shown. The device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The device may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the application described and / or claimed herein.

[0103] like Figure 10 As shown, device 10 includes at least one processor 11 and a memory, such as read-only memory (ROM) 12, random access memory (RAM) 13, etc., communicatively connected to at least one processor 11. The memory stores computer programs executable by at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded into the RAM 13 from storage unit 18. The RAM 13 may also store various programs and data required for the operation of device 10. The processor 11, ROM 12, and RAM 13 are interconnected via bus 14. Input / output (I / O) interface 15 is also connected to bus 14.

[0104] Multiple components in device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of monitors, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0105] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as post-processing methods for AUV positioning data.

[0106] In some embodiments, the AUV positioning data post-processing method can be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the AUV positioning data post-processing method described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to perform the AUV positioning data post-processing method by any other suitable means (e.g., by means of firmware).

[0107] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0108] Computer programs used to implement the methods of this application may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0109] In the context of this application, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium can be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0110] To provide interaction with a user, the systems and techniques described herein can be implemented on a device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0111] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or middleware components (e.g., application servers), or frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0112] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0113] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication unit 19, or installed from storage unit 18, or installed from ROM 12. When the computer program is executed by processor 11, it performs the functions defined in the methods of the embodiments of the present invention.

[0114] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this application can be achieved, and this is not limited herein.

[0115] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method of post-processing AUV positioning data, characterized in that, The method comprises: obtaining a first measurement point sequence and a second measurement point sequence of the AUV in a target time period; wherein the first measurement point sequence is a positioning data set of a first measurement point determined by a strapdown inertial navigation system carried on the AUV, and the second measurement point sequence is a positioning data set of a second measurement point determined by an ultra-short baseline underwater positioning system carried on the AUV; performing trajectory fitting according to the second measurement point sequence to obtain a fitted trajectory, and determining at least two virtual control points based on the fitted trajectory; constructing a measurement section based on two adjacent virtual control points, and matching each first measurement point in the first measurement point sequence with the measurement section according to time to determine a first measurement point corresponding to the measurement section; for each measurement section, correcting the first measurement points in the measurement section according to the virtual control points to obtain corrected measurement points, and determining a corrected trajectory of the AUV based on the corrected measurement points.

2. The method of claim 1, wherein, The second measurement point sequence at least comprises a time sequence, an east coordinate sequence and a north coordinate sequence of the second measurement point; Correspondingly, performing trajectory fitting according to the second measurement point sequence to obtain a fitted trajectory comprises: fitting the time sequence and the east coordinate sequence to obtain a first fitted curve; fitting the time sequence and the north coordinate sequence to obtain a second fitted curve; determining a fitted trajectory according to the first fitted curve, the second fitted curve and the time sequence.

3. The method of claim 1, wherein, The first measurement point sequence at least comprises an azimuth angle sequence of the first measurement point; Correspondingly, after performing trajectory fitting according to the second measurement point sequence to obtain a fitted trajectory, the method further comprises: determining a trajectory attribute of the AUV according to the azimuth angle sequence of the first measurement point; wherein the trajectory attribute comprises a turning section and a straight line section; deleting a trajectory section in the fitted trajectory which is different from the trajectory attribute.

4. The method of claim 1, wherein, For each measurement section, correcting the first measurement points in the measurement section according to the virtual control points to obtain corrected measurement points comprises: for each measurement section, determining a translation deviation according to a first virtual control point in the measurement section and a first measurement point matched with the first virtual control point; determining an azimuth angle deviation according to the virtual control points in the measurement section and the first measurement points; correcting a first first measurement point in the measurement section according to the translation deviation to obtain a corrected measurement point, and correcting other first measurement points in the measurement section according to the translation deviation and the azimuth angle deviation to obtain corrected measurement points.

5. The method of claim 4, wherein, Correcting other first measurement points in the measurement section according to the translation deviation and the azimuth angle deviation to obtain corrected measurement points comprises: correcting the first measurement points in the measurement section to obtain corrected measurement points by using the following formula: ； In the formula, Indicates the first section within the measurement segment The east coordinates of the calibration measuring point corresponding to the first measuring point , Indicates the first section within the measurement segment The north coordinates of the calibration measuring point corresponding to the first measuring point This indicates the east coordinates of the first measuring point within the measurement section. This indicates the north coordinates of the first measuring point within the measurement section. This indicates the translation deviation of the east coordinate. This indicates the translation deviation of the north coordinate. Indicates the distance from the first measurement point to the... The azimuth angle of the line segment between the first measuring points Indicates azimuth deviation. Indicates the first measuring point and the first measuring point within the measuring section. The distance between the first measuring points This represents the distance between the first and last measuring points within the measured section. This indicates the distance between two adjacent virtual control points within the measurement section.

6. The method of claim 4, wherein, Before determining the corrected trajectory of the AUV based on the corrected measurement points, the method further comprises: for a first measurement point before a first virtual control point or after a last virtual control point, correcting the first measurement point according to the translation deviation to determine a corrected measurement point corresponding to the first measurement point.

7. The method of claim 1, wherein, Determining the corrected trajectory of the AUV based on the corrected measurement points comprises: Based on a preset time window, a sliding least square method is used to fit each correction measurement point to determine the correction trajectory of the AUV.

8. An electronic device, comprising: The device comprises: at least one processor; and a memory connected to the at least one processor in communication; wherein the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to perform the post-processing method of AUV positioning data according to any one of claims 1-7.

9. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer instructions for causing the processor to implement the post-processing method of AUV positioning data according to any one of claims 1-7 when executed.

10. A computer program product, characterised in that, The computer program product comprises a computer program which, when executed by a processor, implements the post-processing method of AUV positioning data according to any one of claims 1-7.

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