A ship dynamic high-precision positioning and abnormal behavior identification method

Abstract

The application discloses a kind of ship dynamic high-precision positioning and abnormal behavior identification method, specifically related to navigation positioning technical field;It is through satellite signal propagation time ranging data received by ship, carrier phase data and ship attitude data are time series synchronized and noise is removed;Through the time-varying coupling relationship of the analysis ship body roll and pitch state and sea surface mirror reflection path, output reflection path coupling relationship parameter;Through establishing multipath deviation correction model, the error correction value of satellite signal propagation time ranging data and carrier phase data is calculated;Through extracting ship spatial attitude change characteristics and track geometric shape characteristics, output ship track motion state data;The satellite signal propagation time ranging data and carrier phase data after correction are used to update ship track motion state data, obtain ship positioning track data, output ship abnormal behavior identification result;It improves the detection accuracy and reliability of ship abnormal behavior.

Description

Technical Field

[0001] This invention relates to the field of navigation and positioning technology, and more specifically, to a method for dynamic high-precision positioning and abnormal behavior identification of ships. Background Technology

[0002] In existing ship positioning and monitoring technologies, ships mainly rely on global navigation satellite systems to obtain positioning information and monitor their real-time motion trajectory and attitude. However, the actual marine environment is complex, and the ship's attitude undergoes frequent and significant dynamic changes during navigation. This causes the satellite signals received by the ship to be affected by the specular reflection path of the sea surface, severely reducing the accuracy of real-time trajectory positioning and attitude monitoring.

[0003] Existing technologies lack effective mechanisms to eliminate the impact of multipath effects on satellite signal positioning accuracy under dynamic ship motion, resulting in ships being unable to achieve accurate high-precision positioning and effective identification of abnormal behavior under complex dynamic conditions. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present invention provide a method for high-precision dynamic positioning and abnormal behavior identification of ships to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for high-precision dynamic positioning and abnormal behavior identification of ships includes the following steps:

[0007] S1: Collect satellite signal propagation time ranging data, carrier phase data and ship attitude data received by the ship, perform timing synchronization and noise removal, and output synchronized ship navigation observation data;

[0008] S2: Based on ship navigation observation data, analyze the time-varying coupling relationship between the ship's roll and pitch states and the sea surface mirror reflection path, and output the reflection path coupling relationship parameters;

[0009] S3: Establish a multipath deviation correction model based on the reflection path coupling relationship parameters, calculate the error correction values ​​of satellite signal propagation time ranging data and carrier phase data, and output the corrected satellite signal propagation time ranging data and carrier phase data;

[0010] S4: Based on ship navigation observation data, extract the spatial attitude change characteristics and track geometry characteristics of the ship, and output the ship trajectory motion state data;

[0011] S5: Using the corrected satellite signal propagation time ranging data and carrier phase data, update the ship trajectory motion state data and obtain the ship positioning trajectory data;

[0012] S6: Based on the ship's positioning trajectory data, identify the characteristics of abnormal ship behavior and output the results of abnormal ship behavior identification.

[0013] In a preferred embodiment, S1 specifically refers to:

[0014] Collect satellite signal propagation time ranging data, carrier phase data, and ship attitude data received by the ship;

[0015] The satellite signal propagation time ranging data and carrier phase data are synchronized with the ship attitude data under a unified time reference.

[0016] The satellite signal propagation time ranging data, carrier phase data, and ship attitude data after synchronization processing are subjected to noise removal processing to remove random errors, and the ship navigation observation data after time synchronization and noise removal processing is output.

[0017] In a preferred embodiment, S2 specifically refers to:

[0018] A three-dimensional spatial geometric coordinate system is established based on the ship roll angle, ship pitch angle, satellite incident azimuth angle and satellite incident elevation angle in the ship navigation observation data;

[0019] Calculate the normal vector of the reflection plane formed by the satellite signal and the sea surface mirror in a three-dimensional spatial geometric coordinate system, and determine the incident angle and reflection angle between the original propagation path of the satellite signal and the reflection path of the sea surface mirror.

[0020] Based on the ship's roll angle and pitch angle, a time-varying mapping function for the incident angle and reflection angle is constructed, and the changes in the satellite signal reflection path length and propagation delay are calculated.

[0021] The time-varying mapping function, the change in reflection path length, and the change in propagation delay are parameterized to generate the reflection path coupling parameters.

[0022] In a preferred embodiment, S3 specifically refers to:

[0023] A multipath deviation correction model is constructed based on the reflection path coupling relationship parameters;

[0024] Based on the correction function for satellite signal propagation path length and the correction function for satellite signal propagation delay based on roll and pitch angles, the error correction value for satellite signal propagation time ranging data is calculated by combining roll and pitch angles.

[0025] Using the correction function of roll angle and pitch angle for satellite signal carrier phase, the error correction value of carrier phase data is calculated;

[0026] The error correction values ​​are applied to the satellite signal propagation time ranging data and carrier phase data respectively, and the corrected satellite signal propagation time ranging data and carrier phase data are output.

[0027] In a preferred embodiment, the multipath deviation correction model includes correction functions for the length of the satellite signal propagation path by roll and pitch angles, correction functions for the propagation delay of the satellite signal by roll and pitch angles, and correction functions for the carrier phase of the satellite signal by roll and pitch angles.

[0028] In a preferred embodiment, S4 specifically refers to:

[0029] Determine the spatial attitude change characteristics of a ship based on its attitude data;

[0030] Based on satellite signal propagation time ranging data and carrier phase data, the geometric characteristics of the ship's track are determined by the trajectory curve fitting method;

[0031] Based on the spatial attitude change characteristics and track geometry characteristics of the ship, the motion state data of the ship's motion trajectory is output.

[0032] In a preferred embodiment, S5 specifically refers to:

[0033] Based on the corrected satellite signal propagation time ranging data and carrier phase data, a joint state equation including position coordinate vector, velocity vector and attitude angle vector is established;

[0034] Perform prediction operations on the joint state equations to generate a predicted state vector;

[0035] The predicted state vector is updated by observing and updating the ship trajectory motion state data, calculating the residual vector and correcting the state covariance matrix to obtain the updated state vector.

[0036] The updated state vector is output in latitude and longitude coordinate system format to form ship positioning trajectory data.

[0037] In a preferred embodiment, S6 specifically refers to:

[0038] Based on ship positioning trajectory data, calculate trajectory curvature, heading change amplitude, and turning rate change, and extract trajectory anomaly indicators;

[0039] Calculate the magnitude of changes in hull roll, pitch and yaw based on ship trajectory motion data, and extract attitude anomaly indicators;

[0040] The trajectory anomaly index and attitude anomaly index are compared with preset anomaly thresholds to output the ship's abnormal behavior identification results.

[0041] The technical effects and advantages of the present invention, a method for high-precision dynamic positioning and abnormal behavior identification of ships, are as follows:

[0042] By unifying the timing synchronization and noise removal of satellite signal propagation time ranging data, carrier phase data, and attitude data, high precision and consistency of the data are achieved. By analyzing the time-varying coupling relationship between the ship's roll and pitch states and the specular reflection path of the sea surface, the sources of multipath errors can be accurately extracted. By establishing a multipath deviation correction model, error correction values ​​for satellite signal propagation time ranging data and carrier phase data are calculated, effectively eliminating pseudorange and carrier phase errors caused by attitude changes and ensuring high precision of positioning input. By extracting the spatial attitude change characteristics and track geometry characteristics of the ship, ship trajectory motion state data is obtained, enabling multi-dimensional situational awareness of the ship's motion state. Using the corrected satellite signal propagation time ranging data and carrier phase data, the ship trajectory motion state data is updated to obtain a high-precision ship positioning trajectory, enhancing short-term dynamic tracking capabilities. Based on the ship positioning trajectory data, abnormal ship behavior characteristics are identified, improving the ability to detect abnormal states. High-reliability and high-precision dynamic positioning and abnormal behavior monitoring can be achieved in complex sea conditions. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of a method for high-precision dynamic positioning and abnormal behavior identification of ships according to the present invention. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0045] Example

[0046] Figure 1 This invention presents a method for high-precision dynamic positioning and abnormal behavior identification of ships, which includes the following steps:

[0047] S1: Collect satellite signal propagation time ranging data, carrier phase data and ship attitude data received by the ship, perform timing synchronization and noise removal, and output synchronized ship navigation observation data;

[0048] S2: Based on ship navigation observation data, analyze the time-varying coupling relationship between the ship's roll and pitch states and the sea surface mirror reflection path, and output the reflection path coupling relationship parameters;

[0049] S3: Establish a multipath deviation correction model based on the reflection path coupling relationship parameters, calculate the error correction values ​​of satellite signal propagation time ranging data and carrier phase data, and output the corrected satellite signal propagation time ranging data and carrier phase data;

[0050] S4: Based on ship navigation observation data, extract the spatial attitude change characteristics and track geometry characteristics of the ship, and output the ship trajectory motion state data;

[0051] S5: Using the corrected satellite signal propagation time ranging data and carrier phase data, update the ship trajectory motion state data and obtain the ship positioning trajectory data;

[0052] S6: Based on the ship's positioning trajectory data, identify the characteristics of abnormal ship behavior and output the results of abnormal ship behavior identification.

[0053] S1: Collects satellite signal propagation time ranging data, carrier phase data, and ship attitude data received by the ship; performs timing synchronization and noise removal; and outputs synchronized ship navigation observation data, including:

[0054] Collect satellite signal propagation time ranging data, carrier phase data, and ship attitude data received by the ship;

[0055] Satellite signal propagation time ranging data refers to the satellite navigation signal received by the global satellite navigation receiving equipment on a ship. After the satellite navigation signal is emitted from the satellite navigation signal transmitter, it propagates through space and is received by the global satellite navigation receiving equipment on the ship. The global satellite navigation receiving equipment records the total time required for the satellite navigation signal to travel from the satellite navigation signal transmitter to the global satellite navigation receiving equipment. Based on the speed of electromagnetic waves in a vacuum, the time taken for the propagation process is calculated to obtain the length of the spatial propagation path corresponding to the electromagnetic wave. The length of the spatial propagation path is called satellite signal propagation time ranging data, which reflects the spatial distance between the satellite navigation signal transmitter and the global satellite navigation receiving equipment. Due to various error factors such as atmospheric delay effect and ionospheric effect generated when the electromagnetic wave signal propagates in the atmosphere, the spatial distance differs from the actual distance and is not a true distance measurement value.

[0056] Carrier phase data is the carrier signal phase measurement value of the satellite navigation signal received by the global satellite navigation receiving equipment on the ship. The carrier signal phase measurement value refers to the measurement value obtained by the global satellite navigation receiving equipment by continuously measuring the phase change of the electromagnetic wave carrier carrying position information in the satellite navigation signal. High-precision position information of satellite signal propagation can be obtained through the carrier signal phase measurement value. The carrier phase data reflects the cumulative change trend of the carrier phase change of the global satellite navigation receiving equipment relative to the satellite navigation signal transmitting device during the propagation process.

[0057] Ship attitude data is the three-dimensional rotational attitude data of the ship relative to the geographic spatial coordinate system, which is collected in real time by attitude measurement sensors installed on the ship. It includes roll angle data, pitch angle data, and yaw angle data. Roll angle data is the angle change value of the ship's left and right rotation around the central axis of the direction of travel. Pitch angle data is the angle change value of the ship's pitch rotation around the transverse axis perpendicular to the direction of travel. Yaw angle data is the angle change value of the ship's horizontal rotation around the vertical axis. Ship attitude data can accurately describe the real-time spatial rotational state of the ship during navigation.

[0058] The satellite signal propagation time ranging data and carrier phase data are synchronized with the ship attitude data under a unified time reference.

[0059] Synchronization processing with a unified time reference refers to using the standard Global Navigation Satellite System (GNSS) timing signal as the time reference. The ship's GNSS receiver and attitude measurement sensors both receive and synchronize with the timing signal, ensuring consistency in the time dimension of satellite signal propagation time ranging data, carrier phase data, and ship attitude data. This means that each moment of data acquisition has a completely consistent time stamp. Synchronization processing with a unified time reference includes: the GNSS receiver receiving and processing the time synchronization signal emitted by the GNSS to obtain standard time information; and the attitude measurement sensors simultaneously receiving standard time information and recording the acquisition time corresponding to the current ship attitude data when acquiring ship roll angle, pitch angle, and yaw angle data. Through these methods, a one-to-one correspondence is achieved between satellite signal propagation time ranging data, carrier phase data, and ship attitude data in the time dimension.

[0060] The satellite signal propagation time ranging data, carrier phase data and ship attitude data after synchronization are subjected to noise removal processing to remove random errors, and the ship navigation observation data after time synchronization and noise removal processing is output.

[0061] Noise removal is the process of identifying and removing random interference errors in the time-of-flight ranging data, carrier phase data, and ship attitude data after synchronization. Random interference errors include random electronic noise generated by the receiving electronic components of global satellite navigation equipment, random fluctuations caused by short-term changes in the atmospheric propagation path, and random errors caused by antenna swaying, among other random factors. Specifically, noise removal involves comparing the difference between each data point at each sampling time after synchronization and its adjacent data points. If the difference exceeds a preset statistical threshold, the data point is considered to have a random error, and the erroneous data point is corrected using linear interpolation or a nonlinear smoothing algorithm. The correction method involves taking the data values ​​of adjacent normal data points before and after the erroneous data point and recalculating the normal, reasonable data value using an interpolation algorithm to replace the original erroneous data point. Through this method, random noise and errors in the time-of-flight ranging data, carrier phase data, and ship attitude data can be effectively eliminated, resulting in ship navigation observation data that has undergone time synchronization and noise removal processing.

[0062] S2: Based on ship navigation observation data, analyze the time-varying coupling relationship between the ship's roll and pitch states and the specular reflection path of the sea surface, and output the reflection path coupling relationship parameters, including:

[0063] A three-dimensional spatial geometric coordinate system is established based on the ship roll angle, ship pitch angle, satellite incident azimuth angle and satellite incident elevation angle in the ship navigation observation data;

[0064] The satellite incident azimuth angle refers to the angle along the propagation path of a satellite navigation signal from a navigation satellite to a ship's navigation receiving equipment on the horizontal plane. It is measured using the ship's local geographic coordinate system, with the ship's direction of travel as the reference direction. The angle between the satellite signal's incident direction and the ship's direction of travel is measured clockwise. The accuracy of this angle measurement can be achieved with a high-precision angle measuring device on the ship's antenna array, resulting in a precise satellite incident azimuth angle. The satellite incident elevation angle refers to the angle between the satellite navigation signal's propagation path from a navigation satellite to a ship's navigation receiving equipment and the horizontal plane. This angle is measured using an antenna array mounted on the ship, with the horizontal plane as the reference plane. The angle reflects the satellite's incidence characteristics relative to the ship's position in the vertical direction. Based on the ship's roll angle, pitch angle, satellite incident azimuth angle, and satellite incident elevation angle, a three-dimensional spatial geometric coordinate system is established as follows: the origin of the geographical coordinate system is taken as the origin of the coordinate system; the horizontal axis of the ship's forward direction is taken as the forward axis of the three-dimensional spatial geometric coordinate system; the horizontal axis of the ship perpendicular to the forward direction is taken as the transverse axis of the three-dimensional spatial geometric coordinate system; and the vertical axis perpendicular to the forward and transverse directions is taken as the vertical axis of the three-dimensional spatial geometric coordinate system. The three-dimensional spatial geometric coordinate system during the ship's motion is formed in the above manner.

[0065] Calculate the normal vector of the reflection plane formed by the satellite signal and the sea surface mirror in a three-dimensional spatial geometric coordinate system, and determine the incident angle and reflection angle between the original propagation path of the satellite signal and the reflection path of the sea surface mirror.

[0066] The normal vector of the reflection plane formed by the satellite navigation signal and the sea surface in a three-dimensional geometric coordinate system is calculated as follows: During the propagation of the satellite navigation signal from the satellite navigation signal transmitter to the ship's navigation receiver, the satellite navigation signal undergoes specular reflection with the sea surface. The reflecting surface is the local sea level corresponding to the incident area of ​​the satellite navigation signal. The spatial position of the local sea level is obtained through geometric calculation based on the installation height of the ship's navigation receiver, the incident azimuth angle of the satellite navigation signal, and the incident elevation angle of the satellite navigation signal. Specifically, the installation position of the ship's navigation receiver is taken as the origin of the three-dimensional geometric coordinate system; based on the installation height of the ship's navigation receiver, the incident area of ​​the satellite navigation signal is determined downwards along the vertical axis. The vertical position coordinates of the corresponding local sea level in a three-dimensional geometric coordinate system are determined. Based on the incident elevation angle of the satellite navigation signal, the tangent value corresponding to the incident elevation angle is calculated, and the vertical position coordinates are divided by the tangent value to obtain the horizontal position coordinates of the satellite navigation signal incident area in the three-dimensional geometric coordinate system. Then, based on the incident azimuth angle of the satellite navigation signal, the sine and cosine values ​​corresponding to the incident azimuth angle are calculated to determine the position coordinates of the satellite navigation signal incident area along the forward axis and the horizontal axis of the three-dimensional geometric coordinate system. By determining the vertical and horizontal position coordinates, the spatial position of the local sea level corresponding to the satellite navigation signal incident area is obtained.

[0067] After determining the spatial location of the local sea level, the normal vector of the reflecting plane is calculated. The method for calculating the normal vector is as follows: using the vertical axis direction in the three-dimensional spatial geometric coordinate system as a reference, the incident direction of the satellite navigation signal is determined and expressed in the three-dimensional spatial geometric coordinate system. The process of determining the incident direction of the satellite navigation signal is as follows: taking the straight path formed by the satellite navigation signal from the satellite navigation signal transmitter to the ship navigation receiver as the direction line segment, the extension direction of the direction line segment is defined as the incident direction of the satellite navigation signal, and the spatial angle formed between the incident direction and the vertical axis direction is calculated; then the spatial angle is bisected to obtain the bisected angle; the direction of the normal vector is determined by the bisected angle, specifically, the direction of the normal vector is determined along the bisecting line of the angle formed by the incident direction and the vertical axis direction, specifically starting from the intersection of the local sea level and determining the direction vector upward along the bisecting line of the angle; the direction of the normal vector is determined through the above process.

[0068] After determining the normal vector, calculate the angle of incidence and the angle of reflection between the original propagation path of the satellite navigation signal and the specular reflection path of the sea surface. The angle of incidence is the spatial angle formed between the incident direction of the satellite navigation signal and the normal vector in the three-dimensional geometric coordinate system. The angle of reflection is the spatial angle formed between the reflection path of the satellite navigation signal after specular reflection at the local sea surface and the normal vector. According to the basic principles of optical and electromagnetic wave specular reflection laws, the angle of incidence and the angle of reflection are equal. Therefore, only the angle of incidence needs to be calculated and determined, and the angle of reflection can be directly determined based on the angle of incidence. The angle of incidence is calculated as follows: the normal vector of the reflection plane is used as the reference vector in the three-dimensional geometric coordinate system; the incident direction vector of the satellite navigation signal is used as the measured vector; the direction of the normal vector of the reflection plane is the direction component on the forward direction axis, the lateral direction axis, and the vertical direction axis in the three-dimensional geometric coordinate system; the incident direction vector of the satellite navigation signal is the direction from the position of the navigation satellite to the ship's navigation receiver. The orientation of the receiving device is determined by the components along the three coordinate axes in a three-dimensional geometric coordinate system. The forward direction axis component of the reflection plane normal vector is multiplied by the forward direction axis component of the satellite navigation signal incident direction vector, the lateral direction axis component is multiplied by the lateral direction axis component, and the vertical direction axis component is multiplied by the vertical direction axis component. The results are then summed to obtain the dot product between the reflection plane normal vector and the satellite navigation signal incident direction vector. The lengths of the reflection plane normal vector and the satellite navigation signal incident direction vector are calculated by summing the squares of the forward direction axis component, the lateral direction axis component, and the vertical direction axis component of each vector, obtaining the square root of the sum, which is the length of each vector. The dot product between the two vectors is divided by the product of the lengths of the two vectors to obtain the cosine value of the angle between the vectors. The inverse cosine function is used to calculate the angle corresponding to the cosine value, which is the angle of incidence. According to the law of specular reflection, the reflection angle is set to be the same as the angle of incidence.

[0069] Based on the ship's roll angle and pitch angle, a time-varying mapping function for the incident angle and reflection angle is constructed, and the changes in the satellite signal reflection path length and propagation delay are calculated.

[0070] The ship's roll angle and pitch angle data are used as input variables for a time-varying mapping function, with the incident angle and reflection angle as output variables. Multiple sets of input and output data samples are constructed by collecting roll angle data, pitch angle data, and corresponding incident and reflection angles during ship navigation. A nonlinear fitting method is used to fit the data samples to a function, using the ship's roll angle as the first input variable, the ship's pitch angle as the second input variable, and the incident angle as the output variable. A time-varying mapping function expression is constructed, where the incident angle equals a constant term, plus the linear coefficient of the roll angle variable multiplied by the roll angle, plus the linear coefficient of the pitch angle variable multiplied by the pitch angle, plus the quadratic coefficient of the roll angle multiplied by the square of the roll angle, plus the quadratic coefficient of the pitch angle multiplied by the square of the pitch angle, and plus the interaction coefficient of the roll and pitch angles multiplied by the product of the roll and pitch angles. All these coefficients are obtained from the actual collected data samples using the least squares method. Since the incident angle and reflection angle are equal, the function expression for the reflection angle is completely consistent with that for the incident angle.

[0071] Based on the determined incident angle, the actual propagation path length of the satellite navigation signal from the navigation satellite to the sea surface reflection point and then to the ship's navigation receiving equipment is calculated: The path length from the satellite navigation signal transmitter to the sea surface reflection point is calculated by the spatial distance between the satellite's spatial coordinates and the sea surface reflection point's spatial coordinates; the path length from the sea surface reflection point to the ship's navigation receiving equipment is calculated by the spatial distance between the ship's navigation receiving equipment and the sea surface reflection point; the sum of these spatial distances gives the actual propagation path length of the satellite navigation signal. The ideal propagation path length of the satellite navigation signal is the straight-line path length from the satellite navigation signal transmitter to the ship's navigation receiving equipment without reflection, obtained by calculating the direct spatial distance between the satellite's spatial coordinates and the ship's navigation receiving equipment's position; the change in the satellite signal reflection path length is obtained by subtracting the ideal propagation path length from the actual propagation path length; the change in the satellite signal reflection path length is divided by the propagation speed of electromagnetic waves in a vacuum to obtain the change in propagation delay.

[0072] The time-varying mapping function, the change in reflection path length, and the change in propagation delay are parameterized to generate reflection path coupling parameters.

[0073] The time-varying mapping function expression between the incident angle and the reflection angle is decomposed into a function expression consisting of a constant term, a first-order roll angle term, a first-order pitch angle term, a squared roll angle term, a squared pitch angle term, and an interaction term between roll and pitch angles. The coefficients corresponding to each term are defined as constant parameters, first-order roll coefficients, first-order pitch coefficients, second-order roll coefficients, second-order pitch coefficients, and roll-pitch interaction coefficients, respectively. These coefficients are the coupling relationship parameters of the reflection path to be determined.

[0074] The changes in reflection path length and propagation delay are parameterized: the change in reflection path length is the first output variable, the change in propagation delay is the second output variable, and the ship's roll angle and pitch angle are the input variables. The same nonlinear function fitting method as the incident angle function is used for parameterization. The changes in reflection path length and propagation delay are expressed as functional expressions, each containing a constant term, and first-order terms of roll angle and pitch angle, second-order terms of roll angle and pitch angle, and interaction terms of roll angle and pitch angle.

[0075] Each of the above items has corresponding function coefficients, called the reflection path length variation coefficient and the propagation delay variation coefficient. These function coefficients characterize the correspondence between changes in the ship's roll and pitch angles and the changes in reflection path length and propagation delay. They are obtained by fitting data collected during actual ship navigation using the nonlinear least squares method: the ship's roll and pitch angles are used as input data, and the corresponding changes in reflection path length and propagation delay are used as output data. Construct the above nonlinear function expression, using the undetermined function coefficients as parameters, calculate the difference between the input data and the fitted function expression, and use the nonlinear least squares method to find a set of function coefficients that minimizes the sum of squared differences. Specifically, establish an error sum of squares function, using each undetermined function coefficient as an unknown, calculate the partial derivative of the error sum of squares function with respect to each undetermined function coefficient, and make the obtained partial derivatives equal to zero to obtain a system of nonlinear equations; then solve the system of nonlinear equations to obtain the function coefficients; all the function coefficients obtained through the above process are the parameters of the reflection path coupling relationship.

[0076] S3: Establish a multipath deviation correction model based on the reflection path coupling parameters, calculate the error correction values ​​for satellite signal propagation time ranging data and carrier phase data, and output the corrected satellite signal propagation time ranging data and carrier phase data, including:

[0077] A multipath deviation correction model is constructed based on the reflection path coupling relationship parameters;

[0078] The multipath deviation correction model uses reflection path coupling parameters to mathematically model the interaction between ship roll angle data, ship pitch angle data, and the satellite navigation signal propagation path, thereby correcting errors caused by multipath effects during satellite signal propagation. The multipath deviation correction model includes correction functions for roll and pitch angles on satellite signal propagation path length, roll and pitch angles on satellite signal propagation delay, and roll and pitch angles on satellite signal carrier phase. These three functions respectively demonstrate the direct influence of roll and pitch angles on propagation path length, propagation delay, and carrier phase, enabling precise quantification and effective compensation of multipath effects generated during ship dynamic motion.

[0079] The output of the correction function for the satellite signal propagation path length based on roll and pitch angles is the error value of the satellite navigation signal propagation path length. The function is constructed as follows: based on the reflection path coupling parameters, a function expression is established including a constant term, a first-order term for roll angle, a first-order term for pitch angle, a second-order term for roll angle, a second-order term for pitch angle, and an interaction term between roll and pitch angles. The coefficients corresponding to each term are set according to the reflection path coupling parameters. For example, the constant term coefficient represents the basic error of the satellite signal propagation path length under conditions of no attitude change, and the first-order roll term coefficient represents the error value per unit change in roll angle. The path length error increment caused by the position, the first term coefficient of the pitch angle represents the path length error increment caused by each unit change in pitch angle; the second term coefficients of the roll angle and the second term coefficients of the pitch angle represent the higher-order nonlinear effects of changes in roll angle and pitch angle, respectively; the interaction term coefficients of roll angle and pitch angle reflect the composite effect produced when roll and pitch change simultaneously; each of the above coefficients is assigned a value by the reflection path coupling relationship parameter; by inputting the ship's roll angle and pitch angle collected at any time, the error in the satellite signal propagation path length at the corresponding time can be calculated, and then the satellite signal propagation path length can be corrected;

[0080] The output of the correction function for the satellite signal propagation delay caused by roll and pitch angles is the satellite signal propagation delay error value. This error value is the propagation time difference caused by the change in the actual propagation path length due to changes in ship roll and pitch. The function also establishes functional expressions for constant terms, first-order roll angle terms, first-order pitch angle terms, second-order roll angle terms, second-order pitch angle terms, and interaction terms between roll and pitch angles, based on the reflection path coupling parameters. The coefficients of each term represent the fundamental error, linear error increment, and nonlinear error increment of the propagation delay caused by ship roll and pitch, respectively. For example, the constant term represents the satellite navigation signal... The propagation delay error is the fundamental error that exists when the ship's motion attitude is not affected by changes. The first-order roll term coefficient represents the change in propagation delay corresponding to each unit change in roll angle, and the first-order pitch term coefficient represents the change in propagation delay corresponding to each unit change in pitch angle. The second-order roll and second-order pitch term coefficients represent the higher-order nonlinear effects on propagation delay caused by changes in roll and pitch angles. The interaction term coefficient represents the combined effect on propagation delay when roll and pitch angles change together. By inputting the real-time measured roll and pitch angles, the satellite signal propagation delay error value at the corresponding moment can be calculated, thereby correcting the satellite signal propagation delay.

[0081] The output of the correction function for the satellite signal carrier phase caused by roll and pitch angles is the satellite navigation signal carrier phase error value. The satellite navigation signal carrier phase error value refers to the difference between the measured carrier phase value and the ideal value caused by changes in ship attitude and satellite signal reflection. The function expression includes a constant term, a first-order roll angle term, a first-order pitch angle term, a second-order roll angle term, a second-order pitch angle term, and a roll-pitch interaction term. The coefficients of each term have the following meanings: for example, the constant term represents the basic error of the satellite navigation signal carrier phase error when it is not affected by changes in ship attitude; the first-order roll angle coefficient represents the order of magnitude of the increase in carrier phase error per unit increase in roll angle; the first-order pitch angle coefficient represents the increment of carrier phase error caused by each unit increase in pitch angle; and the second-order and interaction term coefficients reflect more complex nonlinear error characteristics. By inputting the ship's roll and pitch angles measured at any given time, the carrier phase error at that time can be calculated, thus achieving carrier phase data correction.

[0082] Based on the correction function for satellite signal propagation path length and the correction function for satellite signal propagation delay based on roll and pitch angles, the error correction value for satellite signal propagation time ranging data is calculated by combining roll and pitch angles.

[0083] Input the real-time measured roll and pitch angles to obtain the satellite signal propagation path length error and satellite signal propagation delay error; the error correction values ​​of the above satellite signal propagation time ranging data include the satellite signal propagation path length error and satellite signal propagation delay error.

[0084] Using the correction function of roll angle and pitch angle for satellite signal carrier phase, the error correction value of carrier phase data is calculated;

[0085] Input the real-time measured roll and pitch angles to obtain the satellite navigation signal carrier phase error value, and then use the satellite navigation signal carrier phase error value to correct the original carrier phase data.

[0086] The error correction values ​​are applied to the satellite signal propagation time ranging data and carrier phase data respectively, and the corrected satellite signal propagation time ranging data and carrier phase data are output.

[0087] The original satellite signal propagation time ranging data is corrected by subtracting the satellite signal propagation path length error value from the original satellite signal propagation time ranging data to eliminate the error caused by the satellite signal propagation path length. At the same time, the satellite signal propagation delay error value is subtracted from the original satellite signal propagation time corresponding to the original satellite signal propagation time ranging data to obtain the actual satellite signal propagation time after propagation time correction. Then, the actual satellite signal propagation time after propagation time correction is multiplied by the propagation speed of electromagnetic wave signals in a vacuum to obtain the satellite signal propagation time ranging data after propagation delay error correction. Finally, the satellite navigation signal carrier phase error value is subtracted from the original carrier phase data to obtain the corrected carrier phase data.

[0088] The error correction values ​​are applied to the satellite signal propagation time ranging data and carrier phase data respectively, and the corrected satellite signal propagation time ranging data and carrier phase data are output. After the above error correction, the satellite signal propagation time ranging data and carrier phase data are no longer affected by the multipath effect caused by changes in ship roll and pitch attitude, and can reflect the true situation of satellite navigation signal propagation path and carrier phase.

[0089] S4: Based on ship navigation observation data, extract the ship's spatial attitude change characteristics and track geometry characteristics, and output the ship's trajectory motion state data, including:

[0090] Determine the spatial attitude change characteristics of a ship based on its attitude data;

[0091] Spatial attitude change characteristics include the trends of ship roll, pitch, and yaw. Roll angle represents the left-right rotation angle of the ship around its central axis in the direction of travel; pitch angle represents the pitch rotation angle of the ship around a transverse axis perpendicular to the direction of travel; yaw angle represents the horizontal rotation angle of the ship around its vertical axis. By comparing the roll, pitch, and yaw angles over consecutive time periods, the time-dimensional change trends of each angle are calculated. A time window of a certain length is set, and multiple consecutive attitude measurement moments within the time window are selected sequentially. The roll, pitch, and yaw angles at each attitude measurement moment are extracted, and adjacent moments are compared. The roll angle, pitch angle, and yaw angle between attitude measurement moments are calculated to obtain the instantaneous attitude angle change value within each time interval. All instantaneous attitude angle change values ​​are summed in chronological order and then divided by the total duration of the time window to obtain the average rate of change of the roll angle, the average rate of change of the pitch angle, and the average rate of change of the yaw angle. The obtained average rate of change is defined as the trend of change of the corresponding attitude angle, thereby determining the trend of change of the ship's roll angle, the trend of change of the ship's pitch angle, and the trend of change of the ship's yaw angle. For example, when a ship encounters waves during a certain period of time, the ship's hull may exhibit an increasing trend of roll angle and a periodic trend of change of pitch angle.

[0092] Based on satellite signal propagation time ranging data and carrier phase data, the geometric characteristics of the ship's track are determined by the trajectory curve fitting method;

[0093] The geometric characteristics of a ship's trajectory include the curvature of the trajectory, the direction of travel, and the turning rate. Satellite signal propagation time ranging (STM) data and carrier phase data are measured in real-time by the shipborne global satellite navigation system (GPS) receiving equipment and undergo error correction processing, accurately reflecting the ship's actual spatial position. Taking STM data as an example, the corrected STM data represents the ship's position measurement data in the GPS coordinate system, recorded in latitude, longitude, and elevation. Carrier phase data improves the accuracy of position measurement and eliminates atmospheric propagation errors. By arranging the ship's position measurement data from multiple sampling times within a continuous time period in chronological order, an initial discrete trajectory point set is obtained. Then, a trajectory curve fitting method is used to mathematically model the discrete trajectory point set. The fitting method is a cubic spline curve fitting algorithm: selecting multiple consecutive trajectory points, using the latitude and longitude coordinates of each trajectory point as function fitting points, and establishing a piecewise cubic polynomial function, with the starting point and... The endpoints all pass through the positions of two adjacent trajectory points. By satisfying the conditions that the function is continuous and its derivative is continuous at the trajectory points, the coefficients of each term of the polynomial function are determined, thus forming a continuous and smooth ship motion trajectory curve. Through the above calculation process of the fitted curve, the actual navigation path of the ship during the measurement period is determined. Then, the geometric characteristics of the track are calculated based on the fitted curve: the curvature of the curve is calculated to determine the curvature of the motion trajectory. The calculation method is to determine the tangent direction and normal direction at any trajectory point of the curve, and obtain the trajectory curvature by dividing the change in the angle between the tangent directions of adjacent trajectory points on the curve by the change in the curve length between the trajectory points. The method for determining the navigation direction of the motion trajectory is to calculate the difference in latitude and longitude between consecutive trajectory points on the trajectory curve, and use this to determine the navigation direction of the trajectory curve in the local geographic coordinate system. The navigation direction is the angle formed by the line connecting adjacent trajectory points on the trajectory curve and the north axis of the geographic coordinate system. The method for calculating the turning rate of the motion trajectory is to divide the angle of change in the navigation direction of the ship trajectory by the time consumed during the navigation process to determine the trajectory turning rate.

[0094] Based on the spatial attitude change characteristics and track geometry characteristics of the ship, output the motion state data of the ship's motion trajectory;

[0095] The motion state data includes the trends of ship roll, pitch, and yaw, as well as the curvature, direction, and turning rate of the motion trajectory. The calculated spatial attitude change characteristics and track geometry features are used as independent feature vectors to form a set of state data for the ship's motion trajectory. This set is labeled with a unified timestamp to ensure temporal consistency between the attitude change characteristics and track geometry features. The data output format is a structured table, with each record containing the trends of ship roll, pitch, and yaw at the sampling time, along with the curvature, direction, and turning rate of the motion trajectory.

[0096] S5: Using the corrected satellite signal propagation time ranging data and carrier phase data, update the ship trajectory motion state data to obtain ship positioning trajectory data, including:

[0097] Based on the corrected satellite signal propagation time ranging data and carrier phase data, a joint state equation including position coordinate vector, velocity vector and attitude angle vector is established;

[0098] The corrected satellite signal propagation time ranging data and carrier phase data reflect the ship's accurate position in the real space coordinate system. The joint state equation is a mathematical equation established by the motion law between the ship's position, velocity, and attitude angles in the three-dimensional geographic coordinate system, which can simultaneously reflect the changes in position, velocity, and attitude angles. The position coordinate vector includes the ship's position on the Earth's surface, with latitude and longitude coordinates representing the ship's horizontal position and elevation coordinates representing the ship's vertical position. The velocity vector includes the ship's velocity components along the longitude, latitude, and vertical directions in the geographic coordinate system, reflecting the ship's real-time dynamic characteristics. The attitude angle vector includes the ship's angular changes in the roll, pitch, and yaw directions, reflecting the real-time motion changes in the ship's attitude. When establishing the joint state equation, the ship's position coordinate vector and velocity vector at the previous measurement time are used as the basis for the equation. The initial state value is the attitude angle vector. Based on the kinematic changes of the current measurement time relative to the previous measurement time, the state is derived using mathematical relationships such as the change in position equals the integral of the velocity vector over the corresponding time interval, the change in velocity equals the integral of the acceleration caused by the attitude change over time, and the change in attitude angle equals the integral of the attitude angular velocity over time. A joint state equation including position, velocity, and attitude is established. The joint state equation is expressed as follows: the position coordinate of the next moment equals the position coordinate of the previous moment plus the integral of the velocity vector of the previous moment; the velocity vector of the next moment equals the velocity vector of the previous moment plus the integral of the acceleration caused by the change in ship attitude; the attitude angle of the next moment equals the attitude angle of the previous moment plus the integral of the rate of change of attitude angle. Through the above relationships, position, velocity, and attitude angle are linked to form a unified mathematical expression that reflects the dynamic relationship of the ship's motion state.

[0099] Perform prediction operations on the joint state equations to generate a predicted state vector;

[0100] Predictive calculation refers to extrapolating the state values ​​determined at the current measurement moment forward in time based on the motion laws of the joint state equation. The calculation method involves substituting the position coordinates, velocity vector, and attitude angle vector from the previous moment into the joint state equation, and then calculating the predicted position coordinate vector, velocity vector, and attitude angle vector for the next moment. For example, taking a measurement period as an example, if the latitude and longitude coordinates and velocity vector at the current measurement moment are already determined, and the roll, pitch, and yaw angles in the attitude angle vector are also determined, then the position coordinate vector for the next measurement moment is obtained by multiplying the current position coordinate vector by the velocity vector at the current measurement moment by the corresponding time interval; the velocity vector for the next moment is calculated based on the acceleration determined by the velocity vector and attitude angle vector at the current measurement moment; and the attitude angle vector for the next moment is calculated by multiplying the current attitude angle vector by the attitude angular velocity by the corresponding time interval. Through the above calculation process, a predicted state vector for the next moment is formed. The predicted state vector includes the ship's position coordinates, velocity, and attitude angle state at the next measurement moment, reflecting the predicted state trend over a short period of time based on the actual state values ​​at the current measurement moment.

[0101] The predicted state vector is updated by observing and updating the ship trajectory motion state data, calculating the residual vector and correcting the state covariance matrix to obtain the updated state vector.

[0102] The predicted state vector reflects the trend of the ship's state changes, while the ship's trajectory motion state data is the actual measured state value obtained by calculating from the ship's navigation observation data. To eliminate the error between the predicted state vector and the actual measured state value, observation update processing is required. This process involves comparing the predicted state vector with the ship's trajectory motion state data and calculating the difference to obtain a residual vector, which is the difference between the actual measured state value and the predicted state value. The state covariance matrix is ​​then corrected based on the residual vector. The state covariance matrix represents the mathematical representation of the errors between position, velocity, and attitude angles during the ship's state prediction process. The diagonal elements of the matrix represent the variance of the prediction error for each state parameter, while the non-diagonal elements represent the variance of the prediction error for each state parameter. The diagonal elements represent the mutual influence relationship of errors between different state parameters. The state covariance matrix is ​​corrected by calculating the residual vector. The residual vector is multiplied by itself to obtain the matrix of error influence. This matrix is ​​then added to the original state covariance matrix to complete the correction. The corrected state covariance matrix reflects the error relationship after the improvement in the prediction accuracy of each state parameter. The predicted state vector is then adjusted according to the corrected state covariance matrix. Specifically, the predicted state vector is added to the residual vector and weighted by the corrected covariance matrix to obtain the updated state vector. Compared with the original predicted state vector, the updated state vector has higher accuracy and better reflects the changing trend of the actual ship motion state.

[0103] The updated state vector is output in latitude and longitude coordinate system format to form ship positioning trajectory data;

[0104] The updated state vector contains more accurate ship position coordinates, velocity vector, and attitude angles after observation and updates. To intuitively represent the ship's true trajectory and position, the position coordinate vector is extracted from the updated state vector and output in a latitude and longitude coordinate system format. The latitude and longitude coordinate system format is output in the form of North or South latitude representing latitude position and East or West longitude representing longitude position, with latitude and longitude coordinates expressed in degrees, minutes, and seconds, respectively. By continuously outputting the updated position coordinate vectors at multiple consecutive measurement times, accurate and continuous positioning trajectory data of the ship during navigation is formed. The ship positioning trajectory data accurately reflects the ship's true spatial motion trajectory.

[0105] S6: Based on the ship's positioning trajectory data, identify abnormal ship behavior characteristics and output the abnormal ship behavior identification results, including:

[0106] Based on ship positioning trajectory data, calculate trajectory curvature, heading change amplitude, and turning rate change, and extract trajectory anomaly indicators;

[0107] Ship positioning trajectory data represents the continuous navigation position of a ship in latitude and longitude coordinates, reflecting the continuity and accuracy of the ship's actual movement trajectory. Trajectory curvature reflects the degree of curvature of the ship's trajectory during navigation. The calculation method for trajectory curvature is as follows: Select three consecutive trajectory position points from the ship positioning trajectory data, forming a triangle. First, calculate the side lengths of the triangle using the coordinates of the three position points. Then, calculate the area of ​​the triangle with the three position points as vertices. Calculate the trajectory curvature using the proportional relationship between the triangle area and the product of the three side lengths. This proportional relationship is expressed as follows: enlarge the triangle area by four times and then divide by the product of the three side lengths to obtain the trajectory curvature. The heading change amplitude is the magnitude of the change in the ship's navigation direction angle during continuous navigation. The calculation method is as follows: Select two consecutive trajectory position points from the ship positioning trajectory data, and calculate the navigation direction at each position point. The navigation direction is obtained by calculating the difference in latitude and longitude coordinates between the preceding and following positions. That is, first calculate the difference in latitude coordinates... The standard deviation value and the difference in longitude coordinates are used to calculate the heading inclination ratio between the position points. Then, the arctangent function is calculated to obtain the corresponding navigation direction angle. The difference between adjacent navigation direction angle values ​​is then calculated to obtain the heading change amplitude. The turning rate change reflects the speed of change of the ship's navigation direction per unit time. The calculation method is as follows: using the heading change amplitude, divide it by the time interval between adjacent trajectory position points during the navigation process. The time interval is determined by the difference in timestamps of the positioning trajectory data to obtain the turning rate change. Taking the ship's navigation through a specific sea area as an example, if the heading change amplitude is large in a short period of time, the trajectory curvature increases, and the turning rate changes rapidly, it indicates that the ship's trajectory motion state is abnormal during the navigation phase. Select a certain length of continuous navigation trajectory points, and calculate the trajectory curvature, heading change amplitude, and turning rate change in sequence. Then, calculate the average value of the trajectory curvature, the maximum value, the minimum value, and the average value of the heading change amplitude, and the maximum value and the average value of the turning rate change, which are defined as trajectory anomaly indicators.

[0108] Calculate the magnitude of changes in hull roll, pitch and yaw based on ship trajectory motion data, and extract attitude anomaly indicators;

[0109] Ship trajectory motion data reflects the spatial attitude changes of a ship during navigation. To accurately determine whether the ship's attitude changes are abnormal, it is necessary to calculate the amplitudes of roll, pitch, and yaw changes. Specifically, a certain length of continuous measurement time period is selected from the ship trajectory motion data. The difference between the maximum and minimum values ​​of the roll angle, pitch angle, and yaw angle at each continuous attitude measurement moment is calculated to obtain the amplitudes of roll change, pitch change, and yaw change, respectively. For example, when a ship is in a complex navigation environment, if a large change in roll angle is measured in a short period of time, exceeding the range of change during normal navigation, it indicates that the amplitude of roll change is abnormal. The amplitudes of pitch change and yaw change are obtained in the same way and defined as attitude anomaly indicators. Attitude anomaly indicators directly reflect whether the ship's attitude changes are abnormal during navigation.

[0110] The trajectory anomaly index and attitude anomaly index are compared with the preset anomaly threshold, and the ship's abnormal behavior identification results are output.

[0111] The results of abnormal ship behavior identification reflect the identification and judgment of abnormal behaviors occurring during navigation. To identify abnormal behavior, trajectory anomaly thresholds and attitude anomaly thresholds are pre-set. Trajectory anomaly thresholds include trajectory curvature thresholds, heading change amplitude thresholds, and turning rate change thresholds. Attitude anomaly thresholds include roll change amplitude thresholds, pitch change amplitude thresholds, and yaw change amplitude thresholds. The thresholds are determined by analyzing historical navigation data to determine the range of trajectory and attitude changes during normal navigation, and setting thresholds for deviations exceeding the normal range by a certain percentage as anomaly thresholds. In the actual abnormal behavior identification process, the extracted trajectory anomaly indicators are compared item by item with their corresponding trajectory anomaly thresholds: if the trajectory curvature is flat... If the mean value exceeds the trajectory curvature threshold, the maximum value of the heading change exceeds the heading change threshold, or the maximum value of the turning rate change exceeds the turning rate change threshold, then the ship's trajectory is defined as abnormal. Similarly, the attitude abnormality indicators are compared with the corresponding attitude abnormality thresholds. If the roll change exceeds the roll change threshold, the pitch change exceeds the pitch change threshold, or the yaw change exceeds the yaw change threshold, then the ship's attitude is defined as abnormal. Finally, the abnormal behavior identification results are output, recording the time, position coordinates, abnormal trajectory, and attitude characteristic indicators of the ship's abnormal behavior. The abnormal behavior identification results serve as an important basis for navigation safety management and accident early warning, and can effectively support the dynamic monitoring of ship navigation safety.

[0112] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. The semiconductor medium can be a solid-state drive.

[0113] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0114] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and modules described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0115] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or modules may be electrical, mechanical, or other forms.

[0116] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0117] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0118] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0119] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0120] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for high-precision dynamic positioning and abnormal behavior identification of ships, characterized in that, Includes the following steps: S1: Collect satellite signal propagation time ranging data, carrier phase data and ship attitude data received by the ship, perform timing synchronization and noise removal, and output synchronized ship navigation observation data; S2: Based on ship navigation observation data, analyze the time-varying coupling relationship between the ship's roll and pitch states and the specular reflection path of the sea surface, and output the coupling relationship parameters of the reflection path, specifically: A three-dimensional spatial geometric coordinate system is established based on the ship roll angle, ship pitch angle, satellite incident azimuth angle and satellite incident elevation angle in the ship navigation observation data; Calculate the normal vector of the reflection plane formed by the satellite signal and the sea surface mirror in a three-dimensional spatial geometric coordinate system, and determine the incident angle and reflection angle between the original propagation path of the satellite signal and the reflection path of the sea surface mirror. Based on the ship's roll angle and pitch angle, a time-varying mapping function for the incident angle and reflection angle is constructed, and the changes in the satellite signal reflection path length and propagation delay are calculated. The time-varying mapping function, the change in reflection path length, and the change in propagation delay are parameterized to generate reflection path coupling parameters. S3: Establish a multipath deviation correction model based on the reflection path coupling relationship parameters, calculate the error correction values ​​of satellite signal propagation time ranging data and carrier phase data, and output the corrected satellite signal propagation time ranging data and carrier phase data; S4: Based on ship navigation observation data, extract the spatial attitude change characteristics and track geometry characteristics of the ship, and output the ship trajectory motion state data; S5: Using the corrected satellite signal propagation time ranging data and carrier phase data, update the ship trajectory motion state data and obtain the ship positioning trajectory data; S6: Based on the ship's positioning trajectory data, identify the characteristics of abnormal ship behavior and output the results of abnormal ship behavior identification.

2. The method for high-precision dynamic positioning and abnormal behavior identification of ships according to claim 1, characterized in that, S1, specifically: Collect satellite signal propagation time ranging data, carrier phase data, and ship attitude data received by the ship; The satellite signal propagation time ranging data and carrier phase data are synchronized with the ship attitude data under a unified time reference. The satellite signal propagation time ranging data, carrier phase data, and ship attitude data after synchronization processing are subjected to noise removal processing to remove random errors, and the ship navigation observation data after time synchronization and noise removal processing is output.

3. The method for high-precision dynamic positioning and abnormal behavior identification of ships according to claim 2, characterized in that, S3, specifically: A multipath deviation correction model is constructed based on the reflection path coupling relationship parameters; Based on the correction function for satellite signal propagation path length and the correction function for satellite signal propagation delay based on roll and pitch angles, the error correction value for satellite signal propagation time ranging data is calculated by combining roll and pitch angles. Using the correction function of roll angle and pitch angle for satellite signal carrier phase, the error correction value of carrier phase data is calculated; The error correction values ​​are applied to the satellite signal propagation time ranging data and carrier phase data respectively, and the corrected satellite signal propagation time ranging data and carrier phase data are output.

4. The method for high-precision dynamic positioning and abnormal behavior identification of ships according to claim 3, characterized in that, The multipath bias correction model includes correction functions for the length of the satellite signal propagation path due to roll and pitch angles, correction functions for the propagation delay of the satellite signal due to roll and pitch angles, and correction functions for the carrier phase of the satellite signal due to roll and pitch angles.

5. The method for high-precision dynamic positioning and abnormal behavior identification of ships according to claim 4, characterized in that, S4, specifically: Determine the spatial attitude change characteristics of a ship based on its attitude data; Based on satellite signal propagation time ranging data and carrier phase data, the geometric characteristics of the ship's track are determined by the trajectory curve fitting method; Based on the spatial attitude change characteristics and track geometry characteristics of the ship, the motion state data of the ship's motion trajectory is output.

6. The method for high-precision dynamic positioning and abnormal behavior identification of ships according to claim 5, characterized in that, S5, specifically: Based on the corrected satellite signal propagation time ranging data and carrier phase data, a joint state equation including position coordinate vector, velocity vector and attitude angle vector is established; Perform prediction operations on the joint state equations to generate a predicted state vector; The predicted state vector is updated by observing and updating the ship trajectory motion state data, calculating the residual vector and correcting the state covariance matrix to obtain the updated state vector. The updated state vector is output in latitude and longitude coordinate system format to form ship positioning trajectory data.

7. The method for high-precision dynamic positioning and abnormal behavior identification of ships according to claim 6, characterized in that, S6, specifically: Based on ship positioning trajectory data, calculate trajectory curvature, heading change amplitude, and turning rate change, and extract trajectory anomaly indicators; Calculate the magnitude of changes in hull roll, pitch and yaw based on ship trajectory motion data, and extract attitude anomaly indicators; The trajectory anomaly index and attitude anomaly index are compared with preset anomaly thresholds to output the ship's abnormal behavior identification results.

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