Sea target tracking method and system based on double platforms

Abstract

The application provides a sea target tracking method and system based on a double platform, which comprises the following steps: acquiring position information of an observation platform at a first time t c , observing position information of a cooperative platform, observing information of the cooperative platform, and acquiring position information of the observation platform at a second time t f , observing position information, attitude information and observing information of a target; determining a position change amount of the observation platform within a time interval according to the position information; determining first position information of the cooperative platform at the second time t f according to the position change amount and the position information; correcting the attitude information according to the first position information and the second position information; acquiring corrected position information of the target according to the corrected attitude information; and tracking the target by using the corrected position information. The application reduces the requirement for a navigation radar and input information, and improves the accuracy of sea target tracking.

Description

Technical Field

[0001] This invention relates to the field of target tracking technology, and in particular to a method and system for tracking maritime targets based on a dual-platform architecture. Background Technology

[0002] Maritime target tracking is a key technology in fields such as ocean surveillance and maritime search and rescue. Traditional radar tracking systems are mostly based on continuous observation from a single platform, using algorithms such as Kalman filtering and particle filtering to predict and update target trajectories.

[0003] However, the marine environment presents challenges such as complex multipath effects, sea clutter interference, and low-observable targets (such as stealth ships and small fast boats), which limit the target positioning accuracy, anti-jamming capabilities, and data reliability of single-platform radars.

[0004] Existing methods involve using sensors mounted on an aerial platform to simultaneously observe both the cooperative platform and the target, and then using attitude correction algorithms to correct navigation errors on the aerial platform and track maritime targets. However, these methods rely on specific sensors and have high real-time data requirements, making them difficult to apply in real-world scenarios. Summary of the Invention

[0005] This invention provides a dual-platform method and system for tracking maritime targets, which addresses the shortcomings of inaccurate tracking of maritime targets by single-platform radar in existing technologies. It enables tracking of maritime targets based on a single-cycle observation of dual platforms using navigation radar, reducing the requirements for navigation radar and input information, and improving the accuracy of maritime target tracking.

[0006] This invention provides a dual-platform-based method for tracking maritime targets, comprising:

[0007] The observation platform obtains the data at the first moment t. c Location information when observing the cooperative platform and observation information of the cooperative platform And the observation platform at the second time t f Position information when observing the target Attitude information and observation information of the target ;

[0008] According to the location information and location information The position change of the observation platform within the time interval between the first and second time moments is determined, and the position change is determined based on the position change and the observation information of the cooperative platform. Determine the cooperative platform at the second time t f First location information;

[0009] According to the cooperation platform at the second time t f The first position information and the second position information, and the attitude information of the observation platform. Correction is performed based on the corrected attitude information and the observation information of the target. The target is obtained at the second time t. f The corrected position information is used to track the target.

[0010] According to the present invention, a dual-platform-based method for tracking maritime targets is provided, wherein at a second time t, the method is based on the cooperative platform. f The first position information and the second position information, and the attitude information of the observation platform. Before performing the calibration, the following also applies:

[0011] The cooperative platform will be at the second time t f The second position information is used for coordinate transformation, which is then converted to the coordinates of the observation platform at the second time t. f Coordinates in the local geographic coordinate system.

[0012] According to a dual-platform-based method for tracking maritime targets provided by the present invention, the cooperative platform at the second time t is calculated using the following formula. f The second position information is used for coordinate transformation:

[0013]

[0014] in, This is the second position information after coordinate transformation. For the cooperative platform at the second time t f Second location information, This is the transformation matrix from the Earth coordinate system to the local geographic coordinate system. This is the transformation matrix from the geodetic coordinate system to the Earth coordinate system.

[0015] According to the present invention, a dual-platform-based method for tracking maritime targets is provided, wherein the position change of the observation platform during the time interval between the first and second time moments is equal to the position change of the observation platform during the second time moment t. f Location information Located at the observation platform at the first time t c The location information in the local geographic coordinate system is given by the formula:

[0016]

[0017] in, The change in position, This is the transformation matrix from the Earth coordinate system to the local geographic coordinate system. This is the transformation matrix from the geodetic coordinate system to the Earth coordinate system.

[0018] According to the present invention, a dual-platform-based method for tracking maritime targets utilizes the following formula based on the position change and the observation information of the cooperative platform. Determine the cooperative platform at the second time t f First location information:

[0019]

[0020] in, For the cooperative platform at the second time t f The observation platform is located at the second time t f The first location information in the local geographic coordinate system. Let h be the change in position, and h be the transformation from spherical coordinates to rectangular coordinates.

[0021] According to the present invention, a dual-platform-based method for tracking maritime targets is provided. and The formula is:

[0022]

[0023]

[0024] Among them, X g for , or B and L are the latitude and longitude of the observation platform, respectively, and N is the radius of curvature of the ramusoidal circle of the observation platform. ; and Here, represents the major radius and first eccentricity of the Earth's ellipsoid, respectively; H is the geodetic height.

[0025] According to the present invention, a dual-platform-based method for tracking maritime targets is provided, which, based on the cooperative platform at the second time t, achieves the following: f The first position information and the second position information, and the attitude information of the observation platform. Perform correction:

[0026]

[0027] in, and The cooperative platform at the second time t f The observation platform is located at the second time t f The first and second location information in the local geographic coordinate system. For transformations from an unstable coordinate system to a stable coordinate system, The attitude information of the observation platform after correction.

[0028] According to the present invention, a dual-platform-based method for tracking maritime targets is provided. The formula is:

[0029]

[0030] in, The attitude information of the observation platform. , and These are the yaw angle, pitch angle, and roll angle of the observation platform, respectively.

[0031] According to the present invention, a dual-platform-based method for tracking maritime targets is provided, which uses the following formula based on the corrected attitude information and the observation information of the target. The target is obtained at the second time t. f Correction position information:

[0032]

[0033] in, For the target at the second time t f The corrected position information.

[0034] This invention also provides a dual-platform-based maritime target tracking system, comprising:

[0035] The acquisition module is used to acquire the data from the observation platform at time t. c Location information when observing the cooperative platform and observation information of the cooperative platform And the observation platform at the second time t f Position information when observing the target Attitude information and observation information of the target ;

[0036] The calculation module is used to calculate based on the location information. and location information The position change of the observation platform within the time interval between the first and second time moments is determined, and the position change is determined based on the position change and the observation information of the cooperative platform. Determine the cooperative platform at the second time t f First location information;

[0037] The correction module is used to adjust the parameters based on the cooperative platform at the second time t.f The first position information and the second position information, and the attitude information of the observation platform. Correction is performed based on the corrected attitude information and the observation information of the target. The target is obtained at the second time t. f The corrected position information is used to track the target.

[0038] The present invention provides a dual-platform-based method and system for tracking maritime targets. By replacing the simultaneous observation of dual target information by the radar with single-cycle observation of dual-platform information by the navigation radar, attitude correction is achieved, reducing the performance requirements of the navigation radar. Attitude correction is achieved by using the output information of the existing navigation radar system, namely the target position information in the stable carrier coordinate system, which reduces the requirements of the attitude correction algorithm on the input information, is more in line with actual use needs, and improves the accuracy of tracking maritime targets. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0040] Figure 1 This is one of the flowcharts of the dual-platform-based maritime target tracking method provided by the present invention;

[0041] Figure 2 This is a schematic diagram of the parameters in the dual-platform-based maritime target tracking method provided by the present invention;

[0042] Figure 3 This is the second flowchart of the dual-platform-based maritime target tracking method provided by the present invention;

[0043] Figure 4 This is a schematic diagram of the field test scenario in the dual-platform-based maritime target tracking method provided by the present invention;

[0044] Figure 5 This is a schematic diagram of the maritime target tracking error in the dual-platform maritime target tracking method provided by the present invention;

[0045] Figure 6 This is a schematic diagram of the structure of the dual-platform maritime target tracking system provided by the present invention. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0047] The following is combined with Figure 1 The present invention describes a dual-platform-based method for tracking maritime targets, comprising:

[0048] Step 101, obtain the observation platform at the first time t c Location information when observing the cooperative platform and observation information of the cooperative platform And the observation platform at the second time t f Position information when observing the target Attitude information and observation information of the target ;

[0049] Step 102, based on the location information and location information The position change of the observation platform within the time interval between the first and second time moments is determined, and the position change is determined based on the position change and the observation information of the cooperative platform. Determine the cooperative platform at the second time t f First location information;

[0050] Step 103, according to the cooperation platform at the second time t f The first position information and the second position information, and the attitude information of the observation platform. Correction is performed based on the corrected attitude information and the observation information of the target. The target is obtained at the second time t. f The corrected position information is used to track the target.

[0051] like Figure 2 As shown, the input information for the precise tracking method of maritime targets based on a single-cycle observation dual-platform navigation radar includes: the position information of the observation platform when observing the cooperative platform. Location information of the observation platform when observing the target Observational information from the observation platform to the cooperative platform Observational information of the observation platform on the target Attitude information of the observation platform when observing the target Location information of partner platforms (The location of the cooperation platform remains fixed).

[0052] Define the observation information of the observation platform to the cooperative platform and the target. , From the observed true value , Observational system error , and observation random error , The composition has the following relationship:

[0053]

[0054]

[0055] in, , , , , , These are the true values ​​of the observation distance, azimuth, and elevation angles of the observation platform to the cooperative platform and the target, respectively. , , , , , These are the systematic errors of the observation platform's observation range, azimuth, and elevation angles to the cooperative platform and the target, respectively. , , , , , Do not include random errors in the observation distance, azimuth, and elevation angles of the observation platform to the cooperative platform and the target.

[0056] like Figure 3 As shown, the cooperative platform's first and second position information at the second time step are obtained based on the input information. The first position information is the predicted position (approximate position) of the cooperative platform at the second time step. The second position information is the precise position of the cooperative platform at the second time step. Attitude correction is performed based on the predicted and precise positions of the cooperative platform at the second time step. Target position correction is then performed based on the corrected attitude information. Target tracking is then performed using the corrected target position to obtain the precise position of the target.

[0057] This embodiment achieves attitude correction by replacing the radar's simultaneous observation of dual target information with single-cycle observation of dual-platform information by the navigation radar, thus reducing the performance requirements of the navigation radar. It also achieves attitude correction by using the output information of the existing navigation radar system, namely the target position information in the stable carrier coordinate system, which reduces the requirements of the attitude correction algorithm on the input information, making it more in line with actual usage needs and improving the accuracy of tracking sea targets.

[0058] Based on the above embodiments, in this embodiment, according to the cooperative platform at the second time t f The first position information and the second position information, and the attitude information of the observation platform. Before performing the calibration, the following also applies:

[0059] The cooperative platform will be at the second time t f The second position information is used for coordinate transformation, which is then converted to the coordinates of the observation platform at the second time t. f Coordinates in the local geographic coordinate system.

[0060] Based on the above embodiments, this embodiment uses the following formula to calculate the cooperative platform at the second time t. f The second position information is used for coordinate transformation:

[0061]

[0062] in, This is the second position information after coordinate transformation. For the cooperative platform at the second time t f Second location information, This is the transformation matrix from the Earth coordinate system to the local geographic coordinate system. This is the transformation matrix from the geodetic coordinate system to the Earth coordinate system.

[0063] Based on the above embodiments, in this embodiment, the change in position of the observation platform during the time interval between the first and second moments is the change in position of the observation platform at the second moment t. f Location information Located at the observation platform at the first time t c The location information in the local geographic coordinate system is given by the formula:

[0064]

[0065] in, The change in position, This is the transformation matrix from the Earth coordinate system to the local geographic coordinate system. This is the transformation matrix from the geodetic coordinate system to the Earth coordinate system.

[0066] Based on the above embodiments, this embodiment uses the following formula to calculate the position change and the observation information of the cooperative platform. Determine the cooperative platform at the second time t f First location information:

[0067]

[0068] in, For the cooperative platform at the second time t f The observation platform is located at the second time t f The first location information in the local geographic coordinate system. Let h be the change in position, and h be the transformation from spherical coordinates to rectangular coordinates.

[0069] Based on the above embodiments, this embodiment and The formula is:

[0070]

[0071]

[0072] Among them, X g for , or B and L are the latitude and longitude of the observation platform, respectively, and N is the radius of curvature of the ramusoidal circle of the observation platform. ; and Here, represents the major radius and first eccentricity of the Earth's ellipsoid, respectively; H is the geodetic height.

[0073] Based on the above embodiments, this embodiment uses the following method according to the cooperative platform at the second time t. f The first position information and the second position information, and the attitude information of the observation platform. Perform correction:

[0074]

[0075] in, and The cooperative platform at the second time t f The observation platform is located at the second time t f The first and second location information in the local geographic coordinate system. For transformations from an unstable coordinate system to a stable coordinate system, The attitude information of the observation platform after correction.

[0076] When there is no error, theoretically there is However, due to the influence of observation errors and the attitude errors of the observation platform, it is necessary to construct the above formula and use an attitude correction algorithm to reduce the above errors.

[0077] Based on the above embodiments, this embodiment The formula is:

[0078]

[0079] in, The attitude information of the observation platform. , and These are the yaw angle, pitch angle, and roll angle of the observation platform, respectively.

[0080] Based on the above embodiments, this embodiment uses the following formula to calculate the corrected attitude information and the observation information of the target. The target is obtained at the second time t. f Correction position information:

[0081]

[0082] in, For the target at the second time t f The corrected position information.

[0083] Finally, the target's corrected position information is used to track the target using a target tracking algorithm such as the Kalman filter. This embodiment does not limit the target tracking algorithm. The formula for the Kalman filter algorithm is:

[0084]

[0085] in, Let be the target state estimate, k be the time, P be the target state estimate covariance matrix, F be the state transition matrix, Q be the state noise covariance matrix, H be the observation matrix, R be the observation noise covariance matrix, I be the 6th order identity matrix, and z be the observation vector.

[0086] To verify the effectiveness of the method, a field test was conducted in an open water area, using navigation radar to observe two unmanned surface vessels and collect data. Figure 4 This is a schematic diagram of the field test. The specific test procedure is as follows:

[0087] (1) The unmanned surface vessel's navigation control and RTK (Real Time Kinematic) data transmission and reception are activated, and it enters the designated sea area to navigate and perform semi-autonomous control;

[0088] (2) The RTK equipment is powered on to receive high-precision geodetic coordinate information from the observation equipment;

[0089] (3) The inertial navigation system is powered on to receive attitude information from the observation platform;

[0090] (4) The radar is turned on to search for and stably track the cooperative platform and target, and obtain the corresponding range, azimuth and elevation information;

[0091] (5) The location information, inertial navigation information and radar observation information of the unmanned surface vessel and observation platform are transmitted back to the information processor to realize the tracking of maritime targets.

[0092] Using the method proposed in this invention to track targets, the tracking error of maritime targets is as follows: Figure 5 As shown, the tracking accuracy is significantly improved compared to direct filtering, which has certain practical application value.

[0093] The following describes the dual-platform-based maritime target tracking system provided by the present invention. The dual-platform-based maritime target tracking system described below can be referred to in correspondence with the dual-platform-based maritime target tracking method described above.

[0094] like Figure 6 As shown, the system includes an acquisition module 601, a calculation module 602, and a correction module 603, wherein:

[0095] The acquisition module 601 is used to acquire the observation platform at the first time t. c Location information when observing the cooperative platform and observation information of the cooperative platform And the observation platform at the second time t f Position information when observing the target Attitude information and observation information of the target ;

[0096] The calculation module 602 is used to calculate based on the location information. and location information The position change of the observation platform within the time interval between the first and second time moments is determined, and the position change is determined based on the position change and the observation information of the cooperative platform. Determine the cooperative platform at the second time t f First location information;

[0097] The correction module 603 is used to adjust the compensation module according to the second time t of the cooperative platform. f The first position information and the second position information, and the attitude information of the observation platform. Correction is performed based on the corrected attitude information and the observation information of the target. The target is obtained at the second time t. f The corrected position information is used to track the target.

[0098] This embodiment achieves attitude correction by replacing the radar's simultaneous observation of dual target information with single-cycle observation of dual-platform information by the navigation radar, thus reducing the performance requirements of the navigation radar. It also achieves attitude correction by using the output information of the existing navigation radar system, namely the target position information in the stable carrier coordinate system, which reduces the requirements of the attitude correction algorithm on the input information, making it more in line with actual usage needs and improving the accuracy of tracking sea targets.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for tracking maritime targets based on a dual-platform architecture, characterized in that, include: The observation platform obtains the data at the first moment t. c Location information when observing the cooperative platform and observation information of the cooperative platform And the observation platform at the second time t f Position information when observing the target Attitude information and observation information of the target ; According to the location information and location information The position change of the observation platform within the time interval between the first and second time moments is determined, and the position change is determined based on the position change and the observation information of the cooperative platform. Determine the cooperative platform at the second time t f First location information; According to the cooperation platform at the second time t f The first position information and the second position information, and the attitude information of the observation platform. Correction is performed based on the corrected attitude information and the observation information of the target. The target is obtained at the second time t. f The corrected position information is used to track the target; The change in position of the observation platform during the time interval between the first and second moments is the change in position of the observation platform at the second moment t. f Location information Located at the observation platform at the first time t c The location information in the local geographic coordinate system is given by the formula: ; in, The change in position, This is the transformation matrix from the Earth coordinate system to the local geographic coordinate system. This is the transformation matrix from the geodetic coordinate system to the Earth coordinate system; The following formula is used to describe the cooperative platform at the second time t. f The first position information and the second position information, and the attitude information of the observation platform. Perform correction: ; in, and The cooperative platform at the second time t f The observation platform is located at the second time t f The first and second location information in the local geographic coordinate system. For transformations from an unstable coordinate system to a stable coordinate system, The attitude information of the observation platform after correction; The formula is: ; in, The attitude information of the observation platform. , and These are the yaw angle, pitch angle, and roll angle of the observation platform, respectively. The following formula is used based on the corrected attitude information and the observation information of the target. The target is obtained at the second time t. f Correction position information: ; in, For the target at the second time t f The corrected position information.

2. The method for tracking maritime targets based on a dual-platform architecture according to claim 1, characterized in that, At the second time t, according to the aforementioned cooperative platform f The first position information and the second position information, and the attitude information of the observation platform. Before performing the calibration, the following also applies: The cooperative platform will be at the second time t f The second position information is used for coordinate transformation, which is then converted to the coordinates of the observation platform at the second time t. f Coordinates in the local geographic coordinate system.

3. The method for tracking maritime targets based on a dual-platform architecture according to claim 2, characterized in that, The cooperative platform at the second time t is expressed by the following formula. f The second position information is used for coordinate transformation: ; in, This is the second position information after coordinate transformation. For the cooperative platform at the second time t f Second location information, This is the transformation matrix from the Earth coordinate system to the local geographic coordinate system. This is the transformation matrix from the geodetic coordinate system to the Earth coordinate system.

4. The method for tracking maritime targets based on a dual-platform architecture according to claim 1, characterized in that, The following formula is used based on the location change and the observation information from the cooperative platform. Determine the cooperative platform at the second time t f First location information: ; in, For the cooperative platform at the second time t f The observation platform is located at the second time t f The first location information in the local geographic coordinate system. Let h be the change in position, and h be the transformation from spherical coordinates to rectangular coordinates.

5. The method for tracking maritime targets based on a dual-platform architecture according to claim 3, characterized in that, and The formula is: ; ; Among them, X g for , or B and L are the latitude and longitude of the observation platform, respectively, and N is the radius of curvature of the ramusoidal circle of the observation platform. ; and Here, represents the major radius and first eccentricity of the Earth's ellipsoid, respectively; H is the geodetic height.

6. A dual-platform-based maritime target tracking system, characterized in that, The method for tracking maritime targets based on a dual platform as described in any one of claims 1-5 includes: The acquisition module is used to acquire the data from the observation platform at time t. c Location information when observing the cooperative platform and observation information of the cooperative platform And the observation platform at the second time t f Position information when observing the target Attitude information and observation information of the target ; The calculation module is used to calculate based on the location information. and location information The position change of the observation platform within the time interval between the first and second time moments is determined, and the position change is determined based on the position change and the observation information of the cooperative platform. Determine the cooperative platform at the second time t f First location information; The correction module is used to adjust the parameters based on the cooperative platform at the second time t. f The first position information and the second position information, and the attitude information of the observation platform. Correction is performed based on the corrected attitude information and the observation information of the target. The target is obtained at the second time t. f The corrected position information is used to track the target.

Images