A real-time prediction system for survey ship's elevation angle based on trajectory integral extrapolation

Abstract

The present invention relates to a system for real-time prediction of target jet elevation angle based on ballistic integral extrapolation. The system designs a universal target jet elevation angle real-time prediction calculation framework, realizes the simultaneous calculation of target jet elevation angle using multiple guidance source trajectory data and ship position data, and solves the problem of jet elevation angle prediction when the target flight deviation is large. The display view of the real-time prediction of jet elevation angle designed by the present invention includes a table display and a graphic display. The table display can observe the detailed information of the forecast in real time; the graphic display can intuitively show the changing trend of the forecast result. The present invention adopts a method of separating data and display, designs a universal database table, realizes the configurability of guidance source trajectory, ship posture and position data, and is suitable for various different types of tasks.

Description

Technical Field

[0001] The present invention belongs to the field of aerospace measurement and control data processing, and specifically relates to a real-time prediction system for the elevation angle of a survey ship based on ballistic integral extrapolation. The system is mainly used for real-time calculation of the elevation angle (highest elevation angle) of a measurement and control target during tracking, and for real-time graphical display of historical prediction data, thereby providing decision-making information for variable heading measurement during low-elevation-angle tracking of the survey ship and high-elevation-angle tracking plus target feedforward of a pulse radar. Background Art

[0002] Aerospace measurement vessels are equipped with numerous devices on their decks, including multiple radar antennas used for space tracking and control missions. Each of these devices is subject to varying degrees of obstruction when the target is at low elevation angles. To ensure optimal performance of the tracking and control equipment, measurement vessels are generally required to maintain a straight and constant speed when performing aerospace tracking and control missions. When designing navigation conditions, the overall tracking and control system must fully consider the target elevation angle and equipment obstruction. At low target elevation angles, it is impossible to achieve both straight-line navigation and unobstructed tracking of the equipment. To ensure continuous tracking, the vessel must turn and perform variable-course measurements. Since turning is a process, implementing variable-course measurements requires advance decision-making based on target elevation angle prediction.

[0003] When tracking highly dynamic targets at high elevation angles, pulse radars installed on survey vessels require target feedforward to be superimposed before the target reaches the high elevation angle to ensure stable tracking. In other cases, superimposing target feedforward is detrimental to stable tracking. Therefore, real-time prediction of the target's elevation angle is crucial for pulse radars to stably track highly dynamic targets.

[0004] To meet the requirements of ship course control and pulse radar coupled with target feedforward decision-making, a real-time target elevation angle prediction system was developed. This system integrates and extrapolates trajectory data from various available target guidance sources, combined with the survey vessel's position information, to determine the elevation angle at the target's elevation angle. The system then graphically displays the real-time prediction results.

[0005] To calculate the target's elevation angle, the target's position (i.e., the target guidance source's trajectory data) and the survey vessel's position are required. Data transmission and reception utilizes a group-addressed broadcast method, with identification codes within the data packets distinguishing between different types of data. All survey vessel display data is broadcast over the network via a display broadcast group. This broadcast group address allows the acquisition of target position information (such as external trajectory data and equipment-measured trajectory data) and the survey vessel's position (inertial navigation data). Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a real-time prediction software system for the elevation angle of a ship based on ballistic integral extrapolation. After receiving the ballistic data of the target guidance source and the ship position information, the system uses a data-driven method to calculate the elevation angle of the target ship in real time and display it in real time.

[0007] The technical solution adopted by the present invention to solve the above problems is: a real-time prediction system for aircraft elevation angle based on trajectory data integral extrapolation, which includes three parts: a parameter configuration module, a data receiving and processing module, and a data display module, wherein:

[0008] 1. Parameter configuration module. The parameter configuration module is used to configure the parameters used by the system, mainly including ship position information and guidance source trajectory information. Two database tables are designed: "Target Guidance Source Description Table" and "Ship Attitude and Position Data Table".

[0009] The target guidance source description table stores target guidance source trajectory data information used to predict the target elevation angle, and the table structure is defined as shown in Table 1.

[0010] Table 1 Target boot source description table

[0011]

[0012] The Ship Attitude and Position Data Table stores basic information about the ship attitude and position equipment on a spacecraft. A survey ship may have multiple sets of ship attitude and position measurement equipment, and the data from one set should be used for actual calculations.

[0013] Table 2 Ship attitude and position data

[0014]

[0015] Sort the "Guidance Source Identification Number" in ascending order by "Calculation Flag" and read the records in the "Target Guidance Source Description Table" where the "Calculation Flag" is TRUE. Based on the "Ship Attitude and Position Identification Number" in each row, read the corresponding information from the "Ship Attitude and Position Data Table." For each record in the "Target Guidance Source Description Table" where the "Calculation Flag" is TRUE, create a trajectory prediction processing class object. This class contains the "Guidance Source Name," "Guidance Source Trajectory Identification Code," "Inertial Navigation Identification Code," "Inertial Navigation Source Identification," trajectory data, ship position data, and the corresponding trajectory prediction function.

[0016] 2. Data Receiving and Processing Module. This module primarily receives ship position data, guidance source trajectory data, and calculates the elevation angle of the aircraft. It first determines the type of data received, identifies the guidance source trajectory data using the identification code, and then determines the ship position using the identification code and source identifier. If the guidance source trajectory data and corresponding inertial navigation data configured in the database are received, the corresponding trajectory data processing objects are updated after dimensional conversion, and the elevation angle prediction function is activated. If the prediction is successful, the results are displayed on the main interface of the software.

[0017] 3. Data display module. The data display module is used to display the current time scale, current elevation angle and predicted time scale, elevation angle, azimuth angle and other information of various ballistics in real time. The screen is displayed in the form of tables and curves. The upper half of the view is a tabular display of the real-time prediction results of the ballistics of each guidance source; the lower half of the view is a graphical display of the real-time prediction results of the ballistics of each guidance source, such as Figure 1 The number of boot sources in the tabular and graphical displays is consistent with the number of records with the "Calculation Flag" set to TRUE in the user-configured "Target Boot Source Description Table."

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. The present invention realizes a real-time prediction and calculation method for target elevation angle. The method can simultaneously calculate the target elevation angle using trajectory data and ship position data of multiple guidance sources, providing key decision-making information for ship course measurement and pulse radar plus target feedforward.

[0020] 2. The present invention designs a method for real-time display of Hangjie elevation angle forecast results. This method can not only display detailed information of the current forecast source and forecast results in a tabular form, but also display historical forecast data curves to intuitively reflect the changing trend of the forecast results.

[0021] 3. The present invention provides a universal method for real-time prediction of target elevation angle. This method can flexibly configure the trajectory source and ship position data used to predict the elevation angle of the target through database parameter settings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the main interface of the Hangjie elevation angle real-time prediction system developed based on this invention. The Hangjie elevation angle real-time prediction system receives various guidance source trajectory data and ship inertial navigation data in real time, calculates the target Hangjie elevation angle, and displays the results in tables and graphics.

[0023] Figure 2 This is the system composition block diagram of this system.

[0024] Figure 3 This is the data receiving and processing flow chart of this system. DETAILED DESCRIPTION

[0025] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0026] 1. Data initialization.

[0027] Read database tables according to certain orders and rules, and perform validity checks on the data in the database tables, including:

[0028] The "Calculation Flag" is set to "TRUE" in the "Target Guidance Source Description Table" and reads the corresponding information from the "Ship Attitude and Position Data Table" based on the "Guidance Source Identification Number" in each row. For each valid record, a trajectory prediction processing class object is created. This class contains the "Guidance Source Name," "Guidance Source Trajectory Identification Code," "Inertial Navigation Identification Code," "Inertial Navigation Source Identification," trajectory data, ship position data, and the corresponding trajectory prediction function.

[0029] 2. View initialization.

[0030] Count the number of records in the "Target Guidance Source Description Table" whose "Calculation Flag" field is TRUE. Draw a tabular display of the trajectory prediction results of each guidance source in the upper half of the view in ascending order of "Guidance Source Identification Number"; add a graphical display of the trajectory prediction results of each guidance source in the lower half of the view.

[0031] 3. Data reception.

[0032] The software runs on the ship's measurement and control data business network and receives two types of data according to the communication protocol: ① ballistic data of various guidance sources, from which the target trajectory time scale, Earth-centered fixed position vector and velocity vector are extracted; ② ship attitude and position data of the inertial navigation equipment, from which the current ship position information is obtained.

[0033] 4. Calculation of the aircraft elevation angle forecast.

[0034] The specific description is as follows:

[0035] (1) The collected geocentric II trajectory data DD_DX2_0 is converted to the inertial navigation horizontal system, and the time scale t0, azimuth angle A0, and elevation angle E0 of the original trajectory are recorded.

[0036] Convert geocentric fixed rectangular coordinates to inertial navigation horizontal rectangular coordinates

[0037] Location:

[0038] Speed ​​(including ship speed):

[0039] speed:

[0040] in

[0041] Parameter Description

[0042] The geodetic latitude and longitude, geodetic altitude of the inertial navigation origin (ship position)

[0043] Position coordinates of the inertial navigation origin in the Earth-centered fixed system

[0044] Inertial navigation horizontal rectangular coordinates

[0045] Geocentric rectangular coordinates

[0046] Inertial navigation north velocity

[0047] Inertial navigation eastward speed

[0048] Meridian and zodiac components of the vertical deviation of the inertial navigation origin

[0049]

[0050]

[0051]

[0052] Approximately, there are

[0053]

[0054] Convert rectangular coordinates to polar coordinates:

[0055]

[0056]

[0057]

[0058] Parameter Description

[0059] Rectangular coordinate parameters

[0060] Polar coordinate parameters

[0061] (2) The collected geocentric II trajectory data DD_DX2_0 is converted into the geocentric inertial system trajectory DD_dxgx_0.

[0062] The conversion from the Earth-fixed coordinate system to the Earth-centered inertial system is expressed by the following formula:

[0063]

[0064] in

[0065]

[0066] Convert the required data:

[0067] Parameter Description

[0068] Geocentric rectangular coordinates

[0069] Geocentric rectangular coordinates

[0070] Earth's angular velocity of rotation

[0071] From a certain moment Time interval counted from

[0072] (3) Runge-Kutta integration extrapolation for the geocentric inertial system trajectory DD_dxgx_0, with an integration extrapolation step size of 1 second, and extrapolate to obtain the geocentric inertial system trajectory I DD_dxgx_1; convert the geocentric inertial system trajectory I DD_dxgx_1 to the inertial navigation local level system, and record the time scale t1, azimuth angle A1, and pitch angle E1 of the extrapolated trajectory. If E1 > E0, the elevation angle increase count is incremented by 1; if E1 < E0, the elevation angle decrease count is incremented by 1.

[0073] The transformation from the geocentric inertial system to the earth-fixed coordinate system is expressed by the following formula:

[0074]

[0075] (4) Let DD_dxgx_0 = DD_dxgx_1, E0 = E1, and repeat step (3) until the overflight of the target outputs the overflight elevation angle, azimuth angle, and time scale.

[0076] 5. Display of the overflight elevation angle prediction result.

[0077] Update the table control and curve graph control in the graphical interface with the prediction result of step 4.

[0078] In addition to the above embodiments, the present invention also includes other implementation manners. All technical solutions formed by using equivalent transformations or equivalent replacements shall fall within the protection scope of the claims of the present invention.

Claims

1. A real-time prediction system for aircraft elevation angle based on trajectory data integration and extrapolation, characterized by: The system consists of three parts: parameter configuration module, data receiving and processing module and data display module, among which: The parameter configuration module is used to configure the parameters used by the system, including ship position information and guidance source trajectory information; The data receiving and processing module completes the reception of ship position data, guidance source trajectory data and the calculation of the elevation angle of the ship; The data display module is used to display the current information of various trajectories in real time. The upper half of the view is a tabular display of the real-time prediction results of the trajectory of each guidance source; the lower half of the view is a graphical display of the real-time prediction results of the trajectory of each guidance source; The data receiving and processing module first determines the type of data received by the network, determines the guidance source ballistic data by the identification code, and determines the ship position information by the identification code and the signal source identification. If the guidance source ballistic data and the corresponding inertial navigation data configured in the database are received, after dimensional conversion, the ballistic data and ship position data in the corresponding ballistic data processing class object are updated, and the Hangjie elevation angle prediction function is started. After the prediction is successful, the result is displayed on the main interface of the software; The data receiving and processing module receives two types of data according to the communication protocol network: ① various guidance source trajectory data, from which the target trajectory time scale, earth-centered fixed position vector and velocity vector are extracted; ② the ship attitude and position data of the inertial navigation device are used to obtain the current ship position information.

2. The real-time prediction system for aircraft elevation angle based on trajectory data integration and extrapolation according to claim 1 is characterized in that: The parameter configuration module includes two database tables, namely the "Target Guidance Source Description Table" and the "Ship Attitude and Position Data Table". The "Target Guidance Source Description Table" stores the target guidance source trajectory data information used to predict the target elevation angle, specifically including the guidance source identification number, guidance source name, calculation identification, guidance source identification code and ship attitude and position identification number fields; the "Ship Attitude and Position Data Table" stores the basic information of the ship attitude and position equipment of the space measurement ship, specifically including the ship attitude and position identification number, inertial navigation equipment name, inertial navigation data identification code and inertial navigation equipment source identification code fields.

3. The real-time prediction system for aircraft elevation angle based on trajectory data integration and extrapolation according to claim 2 is characterized in that: The specific process of the parameter configuration module is to read the records with "calculation flag" as TRUE in the "target guidance source description table" in ascending order according to the "guidance source identification number", and read the corresponding information in the "ship attitude and position data table" according to the "ship attitude and position identification number" in each row of records; for each record with "calculation flag" as TRUE in the "target guidance source description table", a trajectory prediction processing class object is created, which contains "guidance source name", "guidance source trajectory identification code", "inertial navigation identification code", "inertial navigation signal source identification", trajectory data, ship position data and corresponding trajectory prediction function.

4. The real-time prediction system for aircraft elevation angle based on trajectory data integration and extrapolation according to claim 1 is characterized in that: The Hangjie elevation angle prediction function mainly includes the following steps: 1) Convert the trajectory data to the inertial navigation horizontal system, and record the time scale t0, azimuth angle A0, and elevation angle E0 of the original trajectory. The conversion of geocentric fixed rectangular coordinates to inertial navigation horizontal rectangular coordinates is expressed by the following formula: Location: , Speed, including ship speed: , speed: , Among them, the parameter description is: The origin of inertial navigation, i.e. the geodetic longitude, latitude and altitude of the ship; is the position coordinate of the inertial navigation origin in the Earth-centered fixed system; is the rectangular coordinate of the inertial navigation horizontal system; is the rectangular coordinate of the geocentric fixed system; is the inertial navigation north velocity; is the inertial navigation eastward velocity; It is the meridian and zodiac components of the vertical deviation of the inertial navigation origin; ， ， ， Convert rectangular coordinates to polar coordinates: ， Parameter Description: is the rectangular coordinate parameter; is the polar coordinate parameter; 2) Convert trajectory data to geocentric inertial trajectory The conversion from the Earth-fixed coordinate system to the Earth-centered inertial system is expressed by the following formula: ， in: ， Convert the required data: Parameter Description is the rectangular coordinate of the geocentric fixed system; is the geocentric rectangular coordinate; is the angular velocity of the Earth's rotation; From a certain moment the time interval from which the calculation begins; 3) Geocentric inertial system ballistic Runge-Kutta integration extrapolation, with an integration extrapolation step size of 1 second, and extrapolate to obtain the geocentric inertial system ballistic I; convert the geocentric inertial system ballistic to the inertial navigation local level system, record the time scale t1, azimuth angle A1, and pitch angle E1 of the extrapolated ballistic. If E1 > E0, increment the elevation angle rise count by 1; if E1 < E0, increment the elevation angle fall count by 1. The transformation from the geocentric inertial system to the earth-fixed coordinate system is expressed by the following formula: ； (4)Let the geocentric inertial system ballistic = geocentric inertial system ballistic I, E0 = E1, and repeat step (3) until the target overflight is output, and output the overflight elevation angle, azimuth angle, and time scale.

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