Passive detection analog simulation system based on underwater platform

Abstract

The invention provides a passive detection analog simulation system based on an underwater platform, and belongs to the technical field of analog simulation. The objective of the invention is to solve the problem that an existing analog simulation platform for underwater target tracking lacks the feasibility and reliability influence of a verification target resolving algorithm. The system comprises a laying module, a motion module, a data import module, an interface display module, a network communication module, a process control module, a data recording module, an electronic chart module and an index evaluation module, can meet the requirements of a verification algorithm, simulates the motion trails of an underwater platform and a target, fully verifies the feasibility and reliability of the algorithm, and improves the verification efficiency. And meanwhile, the influence of different maneuvering strategies on a target resolving algorithm can be verified.

Description

Technical Field

[0001] The present invention relates to the technical field of simulation, and more particularly, to a passive detection simulation system based on an underwater platform. Background Art

[0002] In underwater platform target tracking, most of the targets to be tracked should be considered maneuvering targets. Due to the characteristics of the target detection sensors carried by the underwater platform, as well as the constraints on the concealment and mobility of the underwater platform itself, there are many difficulties and problems worthy of research in underwater passive target tracking.

[0003] From a technical perspective, maneuvering target tracking has always been a difficult problem in the field of target tracking. On an underwater platform, this problem is particularly prominent because the target measurement data provided by the target detection sensors on the underwater platform (mainly various sonars) are of a single type, low data rate, large error, and unstable error statistical characteristics. The target motion information is masked in such measurement data, and its extraction is very difficult. More unfavorably, the underwater platform itself has poor maneuverability and it is difficult to improve the observation conditions of the target through large-scale maneuvers to improve the tracking efficiency. Therefore, it is worthy of research to make the target solution algorithm converge quickly in the small maneuver mode.

[0004] Underwater target passive detection technology refers to using a passive sonar detection system to receive the noise radiated by a target, extract information such as the target azimuth after processing, and then complete the tracking of the target through data processing. Since the target can be associated, located, and identified only when the azimuth information is accurate, the underwater target pure azimuth tracking technology is particularly important in the passive sonar detection system. During the process of improving, innovating, and verifying the pure azimuth target solution algorithm, it is necessary to design a simulation system that can meet the requirements of verifying the algorithm, simulate the movement trajectories of the underwater platform and the target, fully verify the feasibility and reliability of the algorithm, and at the same time verify the influence of different maneuvering strategies on the target solution algorithm. Summary of the Invention

[0005] The technical problem to be solved by the present invention is:

[0006] To solve the problem that the existing simulation platform for underwater target tracking lacks the verification of the feasibility and reliability of the target solution algorithm.

[0007] The technical solution adopted by the present invention to solve the above technical problem:

[0008] The present invention provides a passive detection simulation system based on an underwater platform, including a deployment module, a motion module, a data import module, an interface display module, a network communication module, an electronic chart module, and an index evaluation module.

[0009] The deployment module is used to input the data used in the analog simulation process, including the manual input mode and the map deployment mode;

[0010] The motion module includes dead reckoning and motion model construction. The dead reckoning is used to calculate the initial positions of the underwater platform and the target, and the motion model construction is used to establish a three-degree-of-freedom kinematic model of the underwater platform and the target in the horizontal plane; In the training mode, the underwater platform and the target obtain real-time data through model updates. During the simulation process, noise types and noise variance values are added to the heading, speed, and detection azimuth data in the simulation according to the characteristics of the actual sea trial data;

[0011] The data import module is used to import real sea trial data, simulated data generated by the simulation system, and evaluation data, and calculate the convergence effect according to the convergence criterion;

[0012] The interface display module is used to display simulation data in real time, update the motion trajectory in real time, display the solved data in real time, and display the curve in real time;

[0013] The network communication module is used for the transceiver of simulation data and the monitoring of the network connection status;

[0014] The electronic chart module is used to implement the functions of chart deployment and motion trajectory display;

[0015] The index evaluation module is used to record the solved data sent by the solver in real time, calculate the convergence time, convergence distance error, convergence speed error, and convergence heading error of each pure bearing target solving algorithm, and then update the target model according to the kinematic model of the target, and record the position information and attitude information of the target at the corresponding frequency.

[0016] Further, in the deployment module, the manual input mode is used to generate the motion route of the underwater platform and the target according to the target position, attitude information, initial distance between the underwater platform and the target, target beam, underwater platform attitude information, and underwater platform maneuvering strategy; The map deployment mode is used to interact with the electronic chart module to draw the motion route of the underwater platform and the target in the chart and update it in the electronic chart module interface, supplement the attitude information of each section of the underwater platform and the target in the electronic chart module interface, select the maneuvering mode, and generate the corresponding route.

[0017] Further, when calculating the initial position of the underwater platform under the condition of first setting the target state information, the initial coordinates of the underwater platform are calculated by the following formula:

[0018] E QT =E MB +ΔE (1)

[0019] N QT= N MB + ΔN (2)

[0020] Wherein, E MB , N MB respectively represent the target initial eastward coordinate and the initial northward coordinate; E QT , N QT respectively represent the underwater platform initial eastward coordinate and the initial northward coordinate; ΔE represents the eastward coordinate difference between the underwater platform and the target, and ΔN represents the northward coordinate difference between the underwater platform and the target. Their calculation formulas are as follows:

[0021] ΔE = L·sin(ψ MB + σ) (3)

[0022] ΔN = L·cos(ψ MB + σ) (4)

[0023] Wherein, ψ MB represents the target course, σ represents the target aspect angle, and L represents the initial distance between the underwater platform and the target;

[0024] The initial course of the underwater platform is defaulted to point to the target initial azimuth, and is obtained by calculating from the target aspect angle and the target initial course. The formula is as follows:

[0025] ψ QT = ψ MB + σ - 180° (5)

[0026] Wherein, ψ QT represents the underwater platform default course.

[0027] Furthermore, when calculating the initial position of the target after setting the underwater platform status information first, the calculation formula for the initial coordinates of the target is as follows:

[0028] E MB = E QT + ΔE' (6)

[0029] N MB = N QT + ΔN' (7)

[0030] Wherein, E MB , N MB respectively represent the target initial eastward coordinate and the initial northward coordinate; E QT , N QT respectively represent the underwater platform initial eastward coordinate and the initial northward coordinate; ΔE' represents the eastward coordinate difference between the target and the underwater platform, and ΔN' represents the northward coordinate difference between the target and the underwater platform. Their calculation formulas are as follows:

[0031] ΔE' = L·sin(φ) (8)

[0032] ΔN' = L·cos(φ) (9)

[0033] Wherein, φ represents the azimuth angle, and L represents the initial distance between the target and the underwater platform;

[0034] Then, according to the kinematic model of the target, the target is updated, and the position information and attitude information of the target at the corresponding moment are recorded.

[0035] Furthermore, in the motion module, the extraction of the sea trial data characteristics is calculated using the following formula:

[0036]

[0037] Wherein, represents the azimuth angle, represents the true value of the azimuth angle, n i represents the additive noise, N represents the total length of the data, μ represents the noise mean, σ 2 represents the noise variance, γ1 represents the noise skewness, and γ2 represents the noise kurtosis;

[0038] The noise characteristics of the sea trial data are analyzed through the above parameters, and the sea trial data noise is fitted with noises of different distribution types and applied to the simulation scenario.

[0039] Furthermore, the three-degree-of-freedom kinematic models of the underwater platform and the target constructed are both

[0040]

[0041] Wherein, u represents the ship speed along the x direction of the hull, v represents the ship speed along the y direction of the hull, r represents the rotation of the hull around the z axis, ψ represents the angle between the ship's heading and the north, represents the speed of the hull along the N axis direction, represents the speed of the hull along the E axis direction, represents the angular velocity of the angle between the ship's heading and the north.

[0042] Furthermore, the map deployment modes include the automatic turning mode and the manual turning mode. The automatic turning mode is that after the underwater platform arrives at the designated position, it automatically adopts a maneuvering strategy to switch the voyage according to the information set in the system; the manual turning mode is that the user adopts a maneuvering strategy to switch the voyage according to the requirements.

[0043] Further, in the data import module, real sea trial data and simulation data are imported through the human-computer interaction interface. After the data import is completed, corresponding route information is generated and displayed on the electronic chart for repeated simulation training or real sea trial experiments; evaluation data, including underwater platform and target data, and solution data, are imported through the human-computer interaction interface, and the system calculates the convergence effect according to the convergence criterion.

[0044] Further, in the interface display module, the real-time display of simulation data is to display the position and attitude information of the underwater platform and the target, as well as the solution data sent by the solution table, in real time during the training process; real-time display curves are used to display the underwater platform speed, underwater platform heading, target speed, target heading, difference between the solution and the real distance, difference between the solution and the real speed, and difference between the solution and the real heading curves.

[0045] Further, it also includes a process control module and a data recording module. The process control module is used to start, pause, continue, and end the training process, and modify the communication status during the training process, including navigation information status, tracker status, longitude and latitude status, communication frequency, and simulation times; the data recording module is used to store the simulation data generated by the simulation system, the sent communication data and corresponding messages, and the received communication data and corresponding messages in real time.

[0046] Compared with the prior art, the beneficial effects of the present invention are:

[0047] A passive detection simulation system based on an underwater platform of the present invention includes a deployment module, a motion module, a data import module, an interface display module, a network communication module, a process control module, a data recording module, an electronic chart module, and an index evaluation module, which can meet the requirements of verifying algorithms, simulate the motion trajectories of underwater platforms and targets, fully verify the feasibility and reliability of algorithms, and at the same time can verify the influence of different maneuvering strategies on target solution algorithms;

[0048] The present invention simulates and constructs the passive detection environment in various ways, and as much as possible approaches the sea trial environment, and can evaluate and verify the solution data, effectively solving the long-existing problems of the lack of systematic simulation environment and the lack of algorithm verification means in this field; it has functions such as full-link scenario construction, real-time situation display, and index evaluation. Its standardized communication test interface and quantitative evaluation system provide a repeatable and extensible experimental basis for the performance verification and optimization of underwater passive detection algorithms, significantly improving the R & D efficiency and engineering applicability of solution algorithms. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a framework diagram of the passive detection simulation system based on an underwater platform in an embodiment of the present invention;

[0050] Figure 2 It is the flowchart of the release mode in the embodiment of the present invention;

[0051] Figure 3 It is the dead reckoning chart of the underwater platform and the target in the embodiment of the present invention;

[0052] Figure 4 It is the coordinate rotation change chart in the embodiment of the present invention;

[0053] Figure 5 It is the flowchart of the motion module in the embodiment of the present invention;

[0054] Figure 6 It is the main interface diagram of the passive detection simulation system based on the underwater platform in the embodiment of the present invention;

[0055] Figure 7 It is the interface diagram of the map deployment mode in the embodiment of the present invention;

[0056] Figure 8 It is the interface diagram of the manual input mode in the embodiment of the present invention;

[0057] Figure 9 It is the interface diagram of importing data in the embodiment of the present invention;

[0058] Figure 10 It is the drawing interface in the embodiment of the present invention Figure 1 ;

[0059] Figure 11 It is the drawing interface in the embodiment of the present invention Figure 2 ;

[0060] Figure 12 It is the evaluation interface diagram in the embodiment of the present invention. Detailed implementation manner

[0061] To make the above objects, features and advantages of the present invention more obvious and understandable, the following will describe the specific embodiments of the present invention in detail with reference to the accompanying drawings.

[0062] Specific implementation plan one: Combined with Figures 1 to 5 As shown, the present invention provides a passive detection simulation system based on an underwater platform, including a deployment module, a motion module, an imported data module, an interface display module, a network communication module, a process control module, a data recording module, an electronic chart module and an index evaluation module,

[0063] The deployment module is used to input the data used in the simulation process, including the manual input mode and the map deployment mode;

[0064] The manual input mode is used to generate the movement route between the underwater platform and the target based on the target position, attitude information, initial distance between the underwater platform and the target, target side, underwater platform attitude information, and underwater platform maneuvering strategy; through the human-computer interaction interface, manually input the target starting position, total duration of the voyage segment, speed, course, and corresponding disturbance error, manually input the initial distance of the underwater platform, target side angle, speed, course, azimuth noise, duration and speed of each voyage segment, and maneuvering angle between voyage segments; combined with Figure 8 As shown in the manual input mode, according to the prompt information, input the required data, and corresponding voyage segments can be generated on the electronic nautical chart, waiting for the human-computer interaction command to enter the simulation mode;

[0065] The system calculates the initial position of the underwater platform according to formulas (1) to (4):

[0066] E QT = E MB + ΔE (1)

[0067] N QT = N MB + ΔN (2)

[0068] Among them, E MB , N MB represent the target's initial eastward coordinate and initial northward coordinate respectively; E QT , N QT represent the underwater platform's initial eastward coordinate and initial northward coordinate respectively; ΔE represents the eastward coordinate difference between the underwater platform and the target, and ΔN represents the northward coordinate difference between the underwater platform and the target. Their calculation formulas are as follows:

[0069] ΔE = L·sin(ψ MB + σ) (3)

[0070] ΔN = L·cos(ψ MB + σ) (4)

[0071] Among them, ψ MB represents the target course, σ represents the target side angle, and L represents the initial distance between the underwater platform and the target;

[0072] The initial course of the underwater platform is defaulted to point to the target's initial azimuth. Therefore, it can be calculated by the target side angle and the target's initial course. The formula is as follows:

[0073] ψ QT = ψ MB + σ - 180° (5)

[0074] Among them, ψ QTrepresents the default course of the underwater platform; the map deployment mode is used to draw the movement routes of the underwater platform and the target on the nautical chart by interacting with the electronic nautical chart module. The resulting information is updated in the interface, and the attitude information of each section of the underwater platform and the target is supplemented in the interface. The maneuvering mode is selected, including the automatic heading change mode and the manual heading change mode, and the corresponding route can be generated. In the automatic heading change mode, after the underwater platform reaches the specified position, it automatically adopts the maneuvering strategy to switch the section according to the information set in the system. In the manual heading change mode, the user adopts the maneuvering strategy to switch the section according to the requirements.

[0075] Through the human-machine interaction interface, the route points of the underwater platform and the target are directly deployed. Two points are connected to form a section. When deploying the route points on the electronic nautical chart, the distance, time consumption, and heading change angle between the two sections of the current section can be displayed. The speed, speed error, heading error, and azimuth error type can also be set on the deployment interface. After the deployment is completed, the deployed points and the above information can also be modified according to the requirements.

[0076] In the map deployment mode, it is necessary to call the Google Map API and monitor the mouse events of the simulation software. The two are combined to achieve the map calling function. At the same time, the information of each section deployed through the electronic nautical chart can be modified again in the deployment interface. For example, Figure 7 as shown, select the corresponding section, the interface will switch the data to the information of the corresponding section. After manually inputting the data, the data of this section can be directly updated. After confirming that it is correct, the section information is generated through the human-machine interaction interface and enters the simulation mode. After the simulation section is generated, it will return to the main interface and wait for the start of the simulation training, as Figure 6 shown;

[0077] The motion module respectively establishes a three-degree-of-freedom kinematic model of the horizontal plane for the underwater platform and the target. In the training mode, the underwater platform and the target obtain real-time data through model updates. During the simulation process, noise types and noise variance values are added to the heading, speed, and detection azimuth data in the simulation according to the characteristics of the actual sea trial data. The extraction of the characteristics of the sea trial data is calculated using the following formula:

[0078]

[0079] where, represents the azimuth angle, represents the true value of the azimuth angle, n i represents the additive noise, N represents the total length of the data, μ represents the noise mean, σ 2 represents the noise variance, γ1 represents the noise skewness, and γ2 represents the noise kurtosis. The noise characteristics of the sea trial data are analyzed through the above parameters, and the noise of the sea trial data is fitted through different distribution types of noise (such as Gaussian distribution and Laplace distribution) and applied to the simulation scenario.

[0080] including dead reckoning and motion model construction, combined with Figure 3 As shown, dead reckoning is applied to generate the initial azimuth and attitude information of the underwater platform in the manual input mode. Figure 3 In the figure, the triangle is the target position and the ellipse is the underwater platform; given the target coordinates, target bearing, target initial course, and initial distance from the underwater platform to the target, the initial coordinates of the underwater platform are calculated according to the dead reckoning formulas (1) to (4). The initial course of the underwater platform is defaulted to point to the initial azimuth of the target; combined with Figure 4 As shown, a three-degree-of-freedom kinematic model in the horizontal plane is established and applied to the model update of the motion process of the underwater platform and the target. First, the hull coordinate system of the object is rotated with the North East Down (NED) coordinate system, and then a three-degree-of-freedom kinematic model in the horizontal plane based on the NED coordinate system is established. It is used to construct the three-degree-of-freedom kinematic models of the underwater platform and the target, and the angular velocity and speed acceleration during the maneuver of the underwater platform are restricted according to the actual situation. The motion model is as follows:

[0081]

[0082] where, u represents the ship speed along the x direction of the hull, v represents the ship speed along the y direction of the hull, r represents the rotation of the hull around the z axis, and ψ represents the angle between the ship's course and the north. represents the speed of the hull along the N axis direction. represents the speed of the hull along the E axis direction. represents the angular velocity of the angle between the ship's course and the north;

[0083] The data import module is used to import real sea trial data, simulated data generated by this simulation system, and evaluation data; the specified training data text document including real sea trial data and simulation data is imported through the human-computer interaction interface. After the data import is completed, the corresponding route information is generated and displayed on the electronic chart, which is used for repeated simulation training or real sea trial tests, and helps to verify the improvement effect of the algorithm; the evaluation data including underwater platform and target data, and solution data is imported through the human-computer interaction interface, and the system calculates the convergence effect according to the convergence criterion.

[0084] Combined with Figure 9 As shown, when importing simulation data, real sea trial data can be selected for import. The system automatically generates the corresponding motion data of the underwater platform and the target, and conducts simulation according to the actual sea trial training duration; simulation data generated by this simulation platform can also be imported to repeatedly verify the improvement effect of the algorithm; combined with Figure 12As shown, the function of importing evaluation data is located in the evaluation interface, which specifically includes three parts: underwater platform data, target real data, and pure bearing target solution data. The evaluation function can quickly evaluate the algorithm convergence results of multiple simulation trainings;

[0085] The interface display module is used to display simulation data in real time, update the motion trajectory in real time, display the solution data in real time, and display curves in real time. Among them, the real-time display of simulation data is to display the position and attitude information of the underwater platform and the target, as well as the solution data sent by the solution table during the training process in real time; the real-time display of curves can be used to view the curves of the underwater platform speed, underwater platform heading, target speed, target heading, difference between the solution and the real distance, difference between the solution and the real speed, and difference between the solution and the real heading;

[0086] Combined with Figure 6 the shown interface, the simulation data can be viewed in real time and the motion trajectories of the underwater platform and the target in the nautical chart can be viewed; combined with Figure 10 the shown plotting interface, the motion curves of the underwater platform and the target can be viewed in real time, mainly the speed and heading curves; combined with Figure 11 the second shown plotting interface, the error curves of the solution data can be viewed in real time, mainly including the distance error curve, speed error curve, and heading error curve. The convergence of the solution and the convergence effect can be viewed according to these three parts of curves;

[0087] The network communication module is used for the sending and receiving of simulation data and the monitoring of the network connection status. The simulation data sending and receiving function is to simulate the real-time sending of simulation data by the simulation system, receive the solution data (i.e., the current target state data) calculated by the solution table through various different algorithms in real time, and forward it to the interface real-time display module; monitoring the network connection status is to simulate the real-time detection of the network connection status of the solution table by the simulation system. Among them, sending motion simulation data is to send the data generated during the simulation process to the solution table according to the communication protocol; receiving solution data is to receive the algorithm solution data generated by the solution table in real time, and the sending data and receiving data are in one-to-one correspondence through the data packet timestamp; monitoring the network status is to simulate the real-time detection of the online status of the solution table by the simulation system to ensure the integrity of the solution process;

[0088] The process control module is used to control the start, end, pause, continue, etc. of the simulation experiment through the human-computer interaction interface according to requirements; it can also adjust the communication frequency and can select a simulation training rate of 1 to 10 times; it can also set the number of simulation times to achieve long-term automatic continuous training; it can also directly generate the simulation data of this time into a text file to quickly generate simulation data; during the training process of this system, the communication status can be adjusted, including the status of navigation information: normal / fault, the status of the tracker: valid / invalid, the status of longitude and latitude: valid / invalid to verify the reliability and anti-interference ability of the algorithm;

[0089] The data recording module is used to store in real time the simulation data generated by this simulation platform, the communication data and corresponding messages sent by this simulation platform, and the communication data and corresponding messages received by this simulation platform;

[0090] The electronic chart module embeds the Google Map API internally in the system and realizes the function of chart placement and movement trajectory display through interaction with Google Map; during the chart placement process, by dragging the waypoints of the platform and the target on Google Map, a corresponding segment trajectory is formed on the electronic chart, and the latitude and longitude of the starting point and ending point of this segment are returned to this system and processed to generate distance and heading information, and then other data is set to finally complete the initialization of the segment. During the simulation training process, the movement trajectories of the underwater platform and the target are updated in real time on the electronic chart;

[0091] In the electronic chart module, the map placement mode allows dragging the underwater platform and target icons to be placed on the chart, and the electronic chart feeds back the latitude and longitude of the current coordinate point. When the placement points are connected to form a segment, the electronic chart will display the heading, distance, speed, and elapsed time information of the current segment in real time to assist in completing the placement operation; the movement trajectory update is that the real-time trajectories of the underwater platform and the target are updated on the chart during the training process;

[0092] The index evaluation module is used to record in real time the calculation data sent by the calculation platform, and the algorithm evaluation function strictly follows the performance evaluation method for solving the target motion elements by bearing only of underwater platforms in GJB 4328-2002; after the simulation is completed, the corresponding evaluation index values can be input, including: distance index, speed index, heading index. After formula calculation, the convergence time, convergence distance error, convergence speed error, and convergence heading error of each bearing-only target calculation algorithm are obtained; the evaluation is completed based on these four data;

[0093] In the algorithm evaluation module, underwater platform data, calculation data, target data can also be directly imported, or motion data can be generated by model calculation for the target. After the data input is completed, the bearing-only target calculation algorithm evaluation can also be carried out; among them, the dead reckoning of the target is based on: calculating according to the speed, heading, initial bearing, initial distance from the underwater platform, and initial coordinates of the underwater platform; the specific calculation method is as follows:

[0094] E MB =E QT +ΔE' (8)

[0095] N MB =N QT +ΔN' (9)

[0096] Where E MB ,N MBrespectively represent the initial eastward coordinate and the initial northward coordinate of the target; E QT , N QT respectively represent the initial eastward coordinate and the initial northward coordinate of the underwater platform; ΔE' represents the eastward coordinate difference between the target and the underwater platform, and ΔN' represents the northward coordinate difference between the target and the underwater platform. The calculation formulas are as follows:

[0097] ΔE' = L·sin(φ) (10)

[0098] ΔN' = L·cos(φ) (11)

[0099] where, φ represents the azimuth angle, and L represents the initial distance between the target and the underwater platform;

[0100] Then, according to the kinematic model of the target, the model of the target is updated, and the position information and attitude information of the target at the corresponding moment are recorded.

[0101] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art of the present invention can make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will all fall within the protection scope of the present invention.

Claims

1. A passive detection simulation system based on an underwater platform, characterized in that: It includes a deployment module, a motion module, an imported data module, an interface display module, a network communication module, an electronic chart module, and an index evaluation module. The deployment module is used to input the data used in the analog simulation process, including a manual input mode and a map deployment mode. The motion module includes dead reckoning and motion model construction. The dead reckoning is used to calculate the initial positions of the underwater platform and the target, and the motion model construction is used to establish a three-degree-of-freedom kinematic model of the underwater platform and the target in the horizontal plane. In the training mode, the underwater platform and the target obtain real-time data through model updates. During the simulation process, noise types and noise variance values are added to the heading, speed, and detection azimuth data in the simulation according to the characteristics of the actual sea trial data. The imported data module is used to import real sea trial data, simulation data generated by the simulation system, and evaluation data, and calculate the convergence effect according to the convergence criterion. The interface display module is used to display simulation data in real time, update the motion trajectory in real time, display the solved data in real time, and display the curve in real time. The network communication module is used to send and receive simulation data and monitor the network connection status. The electronic chart module is used to implement the functions of chart deployment and motion trajectory display. The index evaluation module is used to record the solved data sent by the solver in real time, obtain the convergence time, convergence distance error, convergence speed error, and convergence heading error of each bearing-only target solving algorithm after calculation, and then update the model of the target according to the kinematic model of the target, and record the position information and attitude information of the target at the corresponding frequency.

2. The passive detection simulation system based on an underwater platform according to claim 1, wherein: In the deployment module, the manual input mode is used to generate the motion route of the underwater platform and the target according to the target position, attitude information, the initial distance between the underwater platform and the target, the target beam, the underwater platform attitude information, and the underwater platform maneuvering strategy. The map deployment mode is used to interact with the electronic chart module to draw the motion route of the underwater platform and the target in the chart and update it in the interface of the electronic chart module, supplement the attitude information of each section of the underwater platform and the target in the interface of the electronic chart module, select the maneuvering mode, and generate the corresponding route.

3. The passive detection simulation system based on an underwater platform according to claim 2, wherein: When calculating the initial position of the underwater platform under the condition of pre-setting the target state information, the initial coordinates of the underwater platform are calculated by the following formula: E QT = E MB + ΔE (1) N QT = N MB + ΔN(2) Among them, E MB , N MB represent the initial eastward coordinate and the initial northward coordinate of the target respectively; E QT , N QT represent the initial eastward coordinate and the initial northward coordinate of the underwater platform respectively; ΔE represents the eastward coordinate difference between the underwater platform and the target, and ΔN represents the northward coordinate difference between the underwater platform and the target. Their calculation formulas are as follows: ΔE = L·sin(ψ MB + σ) (3) ΔN = L·cos(ψ MB + σ) (4) where ψ MB represents the target course, σ represents the target aspect angle, and L represents the initial distance between the underwater platform and the target; The initial heading of the underwater platform is defaulted to point to the initial azimuth of the target, which is obtained by calculating the target beam angle and the initial heading of the target. The formula is as follows: ψ QT = ψ MB + σ - 180° (5) Among them, ψ QT represents the default course of the underwater platform.

4. A passive detection simulation system based on an underwater platform according to claim 2, characterized in that: When calculating the initial position of the target under the condition of pre-setting the underwater platform state information, the calculation formula of the initial coordinates of the target is as follows: E MB = E QT + ΔE' (6) N MB = N QT + ΔN' (7) Among them, E MB , N MB respectively represent the initial eastward coordinate and the initial northward coordinate of the target; E QT , N QT respectively represent the initial eastward coordinate and the initial northward coordinate of the underwater platform; ΔE' represents the eastward coordinate difference between the target and the underwater platform, and ΔN' represents the northward coordinate difference between the target and the underwater platform. Their calculation formulas are as follows: ΔE' = L·sin(φ) (8) ΔN' = L·cos(φ) (9) Where, φ represents the azimuth angle, and L represents the initial distance between the target and the underwater platform. Then, according to the kinematic model of the target, the model of the target is updated, and the position information and attitude information of the target at the corresponding moment are recorded.

5. A passive detection simulation system based on an underwater platform according to claim 3 or 4, characterized in that: In the motion module, the extraction of the characteristics of the sea trial data is calculated by the following formula: Among them, represents the azimuth angle, represents the true value of the azimuth angle, n i represents the additive noise, N represents the total length of the data, μ represents the noise mean, σ 2 represents the noise variance, γ1 represents the noise skewness, and γ2 represents the noise kurtosis; Analyze the noise characteristics of the sea trial data through the above parameters, and then fit the noise of the sea trial data with different distribution types of noise and apply it to the simulation scenario.

6. The passive detection simulation system based on an underwater platform according to claim 5, wherein: The constructed three-degree-of-freedom kinematic models of the underwater platform and the target in the horizontal plane are both where \(u\) represents the hull speed in the \(x\)-direction, \(v\) represents the hull speed in the \(y\)-direction, \(r\) represents the hull rotation about the \(z\)-axis, and \(\psi\) represents the angle between the hull heading and north. represents the hull speed in the \(N\)-axis direction. represents the hull speed in the \(E\)-axis direction. represents the angular velocity of the angle between the hull heading and north.

7. A passive detection simulation system based on an underwater platform according to claim 6, characterized in that: The map deployment modes include the automatic turning mode and the manual turning mode. In the automatic turning mode, after the underwater platform reaches the designated position, it automatically adopts a maneuvering strategy to switch the navigation section according to the information set in the system; in the manual turning mode, the user adopts a maneuvering strategy to switch the navigation section according to the requirements.

8. A passive detection simulation system based on an underwater platform according to claim 7, characterized in that: In the data import module, real sea trial data and simulation data are imported through the man-machine interface. After the data import is completed, the corresponding route information is generated and displayed on the electronic chart for repeated simulation training or real sea trial tests; evaluation data, including underwater platform and target data, and solution data, are imported through the man-machine interface, and the system calculates the convergence effect according to the convergence criterion.

9. A passive detection simulation system based on an underwater platform according to claim 8, wherein: In the interface display module, the real-time display of simulation data is to display the position and attitude information of the underwater platform and the target, as well as the solution data sent by the solution table, in real time during the training process; The real-time display curve is used to display the curves of the underwater platform speed, the underwater platform heading, the target speed, the target heading, the difference between the solution and the real distance, the difference between the solution and the real speed, and the difference between the solution and the real heading.

10. A passive detection simulation system based on an underwater platform according to claim 9, characterized in that: It also includes a process control module and a data recording module. The process control module is used to start, pause, continue, and end the training process, and modify the communication status during the training process, including the navigation information status, the tracker status, the longitude and latitude status, the communication frequency, and the number of simulations; the data recording module is used to store in real time the simulation data generated by the simulation system, the sent communication data and the corresponding messages, and the received communication data and the corresponding messages.

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